Does hydraulically fracturing – or fracking – shale rock have the potential to cause methane contamination of groundwater in England?

By Chris Phoenix Clarke (the report is structured as a scientific paper as part of a final-year university study)

About the report

The report takes a personal viewpoint, targeting curious students and undergraduates, so that they might make up their own minds about fracking in England and how its environmental impact might affect drinking-water supplies.  My aim is to highlight the main protagonists and their respective opinions, along with an evaluation into the claims made and how they withstand scientific scrutiny.  The report will utilise the most relevant and comprehensive scientific evidence available and present it in such a way so that non-specialists can understand, with the hope that hearing both sides of the argument will allow for a proper understanding of the subject.

The report takes a neutral standpoint, with the goal of collating the most up-to-date scientific information on what is undoubtedly one of the most controversial topics of recent times (and yet one that is steeped in uncertainty and lack-of-understanding by the scientific community and the public alike).  Public perception is an important factor when attempting to move forward with any environmentally-sensitive industry, so it is crucial that reliable and accurate information is being offered—and this has never been more applicable than it is with fracking.



The opinion on whether fracking in England can cause contamination of drinking water falls roughly into two camps:  those that believe the dangers are minimal and with proper regulation that fracking should commence (UK government/associated departments); and those that call for a moratorium on fracking until further investigation has been carried out to determine exactly the environmental impacts and its effect on aquifers (Greenpeace, Friends of the Earth (FoE)).

There is, however, a general consensus amongst all parties involved that the most likely cause of contamination is spilled/leaking flowback water from potential well/borehole failure, rather than through the actual process of fracturing shale.  That being said, there is uncertainty—mainly through lack of scientific research—about the possibility of migration of methane towards aquifers as a consequence of shale fracturing.  The available evidence—largely from U.S. case studies—suggests that the closer drinking water wells were to active fracking sites, the higher their concentrations of dissolved methane, with samples less than 1 km away containing 6-20 times more methane than those further away1-2.  A dubious study by Cabot Gas and Oil Corporation of 1701 water wells in Pennsylvania found that concentrations were highly correlated with local topology, with higher readings in valleys than on elevated ground3.  Other results1-2, however, seem to contradict these results.

A study by the U.S. Environmental Protection Agency4 (EPA) provides the only real scientific data on spills/leaks associated with flowback water, showing that spill-rates ranged from 0.4 to 12.2 spills per 100 fracking wells in Colorado/Pennsylvania.  Out of 225 spills examined, 18 saw contaminated water reach drinking water supplies, but of this amount 74% by volume was attributed to surface-container integrity (and not well-failure).  With different, and more robust, regulation in place in England, this risk can be easily mitigated.

The British Geological Survey (BGS) has collected 155 groundwater methane samples to establish a baseline with which future fracking companies can use to monitor any variances during extractions5.  None of the samples exceed the explosive limit for methane.

Possible solutions include: invoking a temporary moratorium on fracking in England until the necessary research and revised regulations are in place; allowing it to go ahead provided baseline methane levels are known and monitored throughout for any fluctuations; and only permit sites to ‘frack’ at sufficient distance from aquifers to reduce risk of contamination.



While fracking in some form or another has been around, on a small scale at least, since the 1940s (Table.1), it hasn’t been until recently that large-scale commercial fracking of shale has become globally widespread, with particular ‘big players’ being the U.S. and China.  Indeed, according to the U.S. Energy Information Administration (EIA)6, the amount of billions of cubic feet of shale gas production in the U.S. has increased from 2.1 in 2008 to 11.4 in 2013, showing that expansion in the industry is rapidly gaining momentum.  This, in turn, makes any environmental concerns associated with groundwater that much more pressing, as any large-scale implementation – in the U.S. or elsewhere – will consequently affect a larger environmental area and a greater number of people.

Table.1 – Shale-gas history summary

The process has, so far, only been undertaken by one company in the UK7 (Cuadrilla), in 2011 near Blackpool, and although the government is “going all out for shale8, no fracking activity has since commenced.

Fracking is the extraction technique of ‘unconventional’ natural gas—predominantly methane—from shale rock.  Fractures are created in the rock by pumping highly-pressurised water, chemicals and sand down well-boreholes (figure.1) and along horizontal pipes to create fissures (the sand, or proppant, used to keep the fractures open)—allowing trapped gas to become liberated (figure.2).


Fig.1 – of hydraulic fracturing (image: Al Granberg/ProPublica)


Fig.2 – Shale gas well design (image: U.S. Department of Energy)

Concerns amongst environmental groups and the public about potential groundwater contamination as a consequence of fracking created much recent controversy, not least from residents in Pennsylvania who reportedly claimed that their proximity to fracking sites actually led to flammable tap water!9  It was speculated that methane liberated by fracking was somehow intruding into drinking water aquifers.

Due to the relative novelty of large-scale fracking operations and the inherent uncertainties associated with the possibility of methane contamination to groundwater, it is no surprise that fracking is a cause for concern as it looks to be implemented on a commercial scale in England.


Are groundwater reserves and aquifers the same thing?
Yes, both describe the same underground reservoirs of water used for drinking water supplies

What is shale?
Shale is deep, sedimentary rock, composed of very fine-grained particles that trap gas from hydrocarbons from escaping

What is the difference between conventional and unconventional gas?
Conventional gas is ‘free’ gas found flowing naturally within the spaces/pores between various rocks; unconventional gas is found trapped within the very low-permeable rock itself and can only be liberated by fracturing



Crudely put, the issue of whether fracking presents a risk to groundwater divides opinion into two camps:  on one side is the UK government who believe that the risks are minimal and that drilling should commence10, and on the other are the environmental groups like Greenpeace and Friends of the Earth (FoE) who call for a moratorium on fracking until further research has been conducted and more stringent regulations in place to mitigate pollution to drinking water aquifers11-12.

The government perceives the risks to groundwater to be more concerned with the wells themselves, rather than the actual process of fracturing the shale.  They recognise a number of hazards dealing with the design, construction and monitoring of the wells that could potentially lead to contamination of aquifers, but believe with robust regulations in place that these risks can be mitigated.  They also state that the risks are no different to well-established and accepted conventional gas drilling methods, and that “a moratorium in the UK is not justified or necessary at present”10.  It has released a number of reports on fracking through its various departments, most notably the Department of Energy & Climate Change (DECC)13, the Energy and Climate Change Committee (ECCC)10 and Public Health England (PHE)14.  It also references a joint report15 by the academic institutions of the Royal Society (RS) and the Royal Academy of Engineering (RAE).

Non-governmental organisations (NGOs) Greenpeace and FoE, whilst agreeing that groundwater contamination from the fractures themselves is unlikely, counter that the chemicals used in the fracking process, coupled with inadequate drilling regulations, still pose a considerable environmental threat  to drinking water aquifers due to well-failure.  They have also released respective reports on the issue11-12, and reference the reports by RS/RAE15 and the British Geological Society (BGS)16.

Where might they be going wrong?  One might speculate that the government’s eagerness to get moving with the industry could be fuelled by the growing energy crisis and the need to bring down costs—possibly rushing its development before the necessary research and regulations are in place.  You might also argue that the anti-fracking lobbyists are campaigning against something that the dangers of which are not yet properly confirmed or understood.

Either way there is much uncertainty surrounding what effect fracking has on groundwater, with only a handful of peer-reviewed studies having been undertaken, and it is these, along with various reports from either side, that are examined in the next section.


What is a moratorium on fracking?
A ban on all fracking activities until further notice.


The evidence

For reasons of clarity the different sources of available evidence will be evaluated individually, with comment as to how they relate to the views held by either side of the argument.

Molofsky et al (2013) conducted a study3 in Pennsylvania into methane sources in groundwater following claims of ignitable drinking water by homeowners in the vicinity.  They concluded that methane is common in the area and is “best correlated with topography and groundwater geochemistry, rather than shale-gas extraction activities”, suggesting that methane from the underlying Marcellus shale had not migrated through extensive pathways created by fracturing, and was not responsible for the methane in the drinking water.  They go on to say that “testing of 1701 water wells… shows that methane is ubiquitous in groundwater, with higher concentrations observed in valleys versus upland areas” (figure 4), implying that valley troughs are the sole cause for increased methane concentrations.

Fig.4 – Elevation map showing dissolved methane levels in 1701 water wells in Pennsylvania.  (Image: Cabot Oil and Gas Corporation)

Upon inspection, however, the objectivity and reliability of the study must be drawn into question as the paper is copyrighted to Cabot Oil and Gas Corporation and one of the contributing authors is an employee.

Osborn et al had undertaken a likewise study in 20111, but generated very different results.  They found that in active fracking areas, methane concentrations in water-wells increased with proximity to the nearest fracking site (with levels being a potential explosion hazard).  In contrast, wells more than 1km from fracking sites averaged nearly 20-times less—implying the underlying and currently-being-‘fracked’ Marcellus shale must be the source of contaminating methane.

Another similar study2 by Jackson et al (2013) found comparable results, stating that dissolved methane was discovered in 82% of samples, with concentrations averaging 6-times higher for homes less than 1km from fracking sites.  They also concluded that distance from fracking wells were the only significant data, finding that the data associated with distances to valley bottoms were not significant.

Both Osborn and Jackson’s papers were published in the respected Proceedings of the National Academy of Sciences with all contributing authors holding posts at academic institutions of varying scientific disciplines.  The papers seem to conflict with Molofsky, going against his conclusion that topography was the cause and seem to implicate fracking activities.

The Royal Society/Royal Academy of Engineering (RS/RAE) released their fracking review15 in 2012, concluding that the risk is “very low” of fractures extending from the shale rock to overlying aquifers providing that the extraction occurs at sufficient depths.  They explain that the geological nature of the intervening strata prevents this.  What is far more likely is well-failure, rather than the hydraulic fracturing of the shale itself, that can cause leaking of contaminated flowback water into the surrounding medium.  As respected academic institutions, one would rely on the findings to be accurate and free of bias.

Public Health England (PHE) in 2014 produced a very similar report14, and agrees that the process of fracking itself is unlikely to cause methane contamination and that the likely source is leakage through the borehole/well.  They advise that “caution is required when extrapolating experiences in other countries to the UK since the mode of operation, underlying geology and regulatory environment are likely to be different”.  Although a government department, PHE’s findings match very closely that of RS/RAE and appear reliable.

Both the RS/RAE and PHE suggest that effective environmental monitoring of methane in the vicinity of fracking sites is needed before, during and after extraction, and particular focus should be paid to designing and maintaining wells to ensure their integrity in order to mitigate leaks.

The British Geological Survey (BGS) compiled a specific report16 on groundwater contamination in 2012 and seemed more open with their conclusions, stating that contamination could potentially be caused by both flowback water (as a result of well-failure), and the constituents of shale gas itself (as a result of the fracturing process, known as fluid leak-off).  It has also been conducting a baseline methane study5 since 2012 to determine nominal levels of dissolved methane throughout the UK (figure.5), in order for the data to be available to fracking companies so they might monitor any variances during/after extraction.  They conclude all levels are below the explosive limit for methane (table 2).  Also a government department, but nevertheless provide comprehensive and relevant information.


Fig.5 – distribution of methane groundwater data (image: BGS)


Table.2 – Summary of the methane baseline results up to January 2015 (Image: BGS)

The U.S. Environmental Protection Agency (EPA) recognises that leaking flowback water from faulty fracking wells poses a risk of contamination to groundwater and estimates that within the states of Colorado/Pennsylvania, spill rates ranged from 0.4 to 12.2 spills per 100 wells4.  Data from 225 well spills were also collected over a six-year period, and it was found that 18 (8%) of the spills reached surface water/groundwater.  But out of the 225 cases, 74% of the total combined spill-volume was attributed to surface-container integrity and not to the wells themselves4.  It also recognises fluid leak-off as a potential, albeit unlikely, risk.

The Department of Energy and Climate Change’s (DECC) 2014 fracking report13 on water attempts to justify the process by stating “Shale gas deposits are hundreds of metres to kilometres below the surface, much deeper than groundwater.  The geology of the UK means that generally there are layers of rock above the shale rock that are impermeable and act as a barrier to contamination”, referencing the findings15 by the RS/RAE.

The Energy and Climate Change Committee’s (ECCC) 2011 fifth report10 on fracking acknowledges fluid leak-off, referencing the EPA report4 and a 1985 study17 by Glenn.  But ultimately they conclude that this is unlikely, and concur that the only real risk of methane contamination of groundwater is via poor well/borehole integrity, and can be mitigated by robust regulation.

Data presented by the EPA4 seem to support the call for a moratorium on UK fracking by Greenpeace and FoE, with the former stating in their 2013 report11as the Gulf of Mexico oil spill has shown, regulating away accidents, spills and failures has proven difficult especially because fracking involves thousands of wells”.


What is flowback fluid?
During and after extraction, a proportion of the water produced by the fracking process returns up the well and may contain a number of dissolved constituents—including liberated methane

How does fluid leak-off work?
It is theorised that fracturing shale can lead to the opening of pathways/faults that might allow the migration of methane/gasses into nearby aquifers



From the evidence evaluated it appears there are a number of clear, albeit competing, solutions to the problem

  • Invoke a temporary moratorium of fracking activities in England pending further research into the potential threats to groundwater and appropriate and revised regulations put in place to mitigate well failure
  • Continue to allow the development of the industry but make mandatory that baseline methane readings are known for every potential site and constant monitoring of these levels undertaken during and after extraction (to see if contamination is occurring as a consequence of extraction)
  • Only allow shale rock deposits to be ‘fracked’ if their proximity to aquifers is sufficiently far enough away to present little or no threat of contamination (further research would be required to establish safe distances)

So, does hydraulically fracturing shale rock have the potential to cause methane contamination of groundwater?  The answer is yes, this does appear to be the case, although there is much uncertainty as to how or to what extent.  The evidence –insofar as current limited studies have allowed – suggests that the actual process of creating fractures deep underground is an unlikely cause of either the U.S. methane results, or potential future methane contamination of English aquifers.  It has been identified, however, that the possibility cannot be ruled out due to fluid leak-off, and it is certainly here that the focus of any further research should be conducted to better understand the probability and potential magnitude of this occurring.

The main cause for possible contamination by methane is flowback fluid transiting through wells of poor design, construction and monitoring, leaking/spilling out into the surrounding medium, eventually finding its way into groundwater reserves.  There is evidence to support that this has already happened in the U.S. (albeit the little data available suggesting surface containers are mostly to blame), and although extrapolating issues in the U.S. to those in England is never an exact science, the severity of the risks demand that well integrity and adequate regulations be addressed and solutions found for each, before any large-scale implementation of fracking in England takes place.

By Chris Phoenix Clarke


Further reading

Environment Agency (EA) –  The risk assessment for fracking in the UK.  The EA is a government department responsible for water quality and resources.

British Geological Survey (BGS) –  Information about UK shale deposits and aquifers.  The BGS is a government department and the foremost scientific authority on UK geological issues.

Department of Energy and Climate Change (DECC) –  Information about fracking regulation and monitoring.  The DECC is the government department tasked with awarding permits and regulating fracking in the UK.

David E. Newton – Fracking:  A Reference Handbook.  A personal, albeit scientific, viewpoint presented as the comprehensive book on fracking.


1Osborn, G. S., Vengosh, A., Warner, R. N., Jackson, B. R. (2011) ‘Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing’, Proceedings of the National Academy of Sciences, vol. 108, no. 20, 8172-8176 [online]. Available at (accessed 29/09/15)

2Jackson, B. R., Vengosh, A., Darrah, H. T., Warner, R. N., Down, A., Poreda, J. R., Osborn, G. S., Zhao, K., Karr, D. J. (2013) ‘Increased stray gas abundance in a subset of drinking water wells near Marcellus shale gas extraction’, Proceedings of the National Academy of Sciences, vol. 110, no. 28, 11250-11255 [online]. Available at (accessed 29/09/05)

3Molofsky, J. L., Connor, A. J., Wylie, S. A., Wagner, T., Farhat, K. S. (2013) ‘Evaluation of methane sources in groundwater in Northeastern Pennsylvania’, Groundwater, vol. 51, no. 3, pp 333-349 [online]. Available at (accessed 29/09/15)

4U.S. Environmental Protection Agency (2015) ‘Assessment of the Potential Impacts of Hydraulic Fracturing for Oil and Gas on Drinking Water Resources’, pp 17 [online]. Available at (accessed 29/09/15)

5British Geological Survey (2015) National methane baseline survey: results summary [online]. Available at (accessed 29/09/15)

6United States Energy Information Administration (2014) Shale gas production data [online]. Available at (accessed 28/05/15)

7Hellier, D. (2015) ‘Fracking: who’s who in the race to strike it rich in the UK’, Guardian, 22 August [online]. Available at (accessed 29/09/15)

8Watt, N. (2014) ‘Fracking in the UK: ‘We’re going all out for shale’ admits Cameron, Guardian, 13 January [online]. Available at (accessed 29/09/15)

9BBC (2011) ‘Bill Ely sets fire to his water supply in Pennsylvania’ 28 November [online]. Available at (accessed 29/09/15)

10Energy and Climate Change Committee (2011) Fifth Report: Shale Gas [online]. Available at (accessed 29/09/15)

11Greenpeace (2013) Fracking: What’s the Evidence? [online]. Available at (accessed 29/09/15)

12Friends of the Earth (2014) All that glitters… Is the regulation of unconventional gas and oil exploration in England really ‘gold standard’? [online]. Available at (accessed 29/09/15)

13Department of Energy & Climate Change (2014) Fracking UK shale: water [online]. Available at (accessed 29/09/15)

14Public Health England (2014) Review of the public health impacts of exposures to chemical and radioactive pollutants as a result of the shale gas extraction process [online]. Available at (accessed 29/09/15)

15Royal Society, Royal Academy of Engineering (2012) Shale gas extraction in the UK: a review of hydraulic fracturing [online]. Available at (accessed 29/09/15)

16British Geological Survey (2012) Potential groundwater impact from exploitation of shale gas in the UK [online]. Available at (accessed 29/09/15)

17Glenn, P. S. (1985) ‘Control and modelling of fluid leakoff during hydraulic fracturing’, Journal of Petroleum Tech, Vol. 37, no. 6, pp 2257-2272


Image references

Figure.1 – (2015) Hydraulic fracturing [online]. Available at (accessed 29/09/15)

Table.1 – Department of Energy & Climate Change n.d. Shale gas background note, pp 3 [online]. Available at (accessed 29/09/15)

Figure.2 – Geological Survey (2012) Potential groundwater impact from exploitation of shale gas in the UK [online]. Available at (accessed 29/09/15)

Figure.3 – Geological Survey (2012) Potential groundwater impact from exploitation of shale gas in the UK [online]. Available at (accessed 29/09/15)

Figure.4 – , J. L., Connor, A. J., Wylie, S. A., Wagner, T., Farhat, K. S. (2013) ‘Evaluation of methane sources in groundwater in Northeastern Pennsylvania’, Groundwater, vol. 51, no. 3, pp 339 [online]. Available at (accessed 29/09/15)

Figure.5 – British Geological Society (2015) National methane baseline survey of UK groundwater [online]. Available at (accessed 29/09/15)

Table.2 –  Geological Society (2015) National methane baseline survey: results summary [online]. Available at (accessed 29/09/15)


Have we reached a crisis-point for critical thinking?

By Chris Phoenix Clarke

In an age where we are bombarded with information from every angle, is it any wonder that a generation of people are becoming unable to tell the difference between what is the truth and what isn’t?

The Internet – for all its wealth of free and accessible information – is certainly a double-edged sword.  Whilst Google and the like have transformed our lives on a scale none could have envisaged, this has come at a cost.  A hefty price tag has been slapped on the box and a line of small print hidden amongst the text; a contract of soul-selling proportions drawn-up unknowingly between humans and a ubiquitous digital entity.  Slowly but surely several billion of us are becoming more stupid, whilst, somewhat ironically, having access to knowledge more vast than we could ever have dreamed of.

It’s the Great Library of Alexandria contained within our living rooms and in our pockets, but infinitely more extensive.

And yet the population lacks mental clarity.  We have lost the ability to think for ourselves.  For amongst the many petabytes and exabytes of the useful information lies countless stores of the bad: the inaccuracies, the misinformation, the lies, the cons, the agendas and propaganda, the corrupt and the just-plain-wrong.  The same bad information previously available in many newspapers and television shows except, in this instance, super-sized and now available at the click of a finger, for free, at all hours of the day and night and with lightning-quick efficiency.  The potential exposure of young minds to this kind of data is now many times greater in magnitude than ever before in history.

“The Great Library of Alexandria contained within our living rooms and in our pockets, but infinitely more extensive”

Those of us born in the 80s or before might recall accumulating knowledge about the world from books, dictionaries, encyclopaedias and videos, before becoming the first real wave of people to experience the Internet in their youth.  Anyone born in the 90s or later would consider the Internet just as much a permanent tool of education as any other – perhaps regarded as the only way in which to access information in some cases.

And herein lies the problem: a generation of people have never had a standard of good information; they’ve not been shown the difference between accurate and inaccurate, or how to recognise the bad.  Furthermore, because anyone can post and share almost anything on the Web, articles spring up looking like genuine news stories but might convey biased or exaggerated information; and because they look like the real thing, people are inclined to believe what they’re reading at first glance and without a moment’s hesitation, so the bad information is subsequently transferred on and spreads like a disease.

Shock media headlines generated to sell newspapers and generate Internet 'clicks' are nearly always bogus.
Shock media headlines generated to sell newspapers and generate Internet ‘clicks’ are nearly always bogus.

In olden times it used to be a case of ‘cutting through the crap’ and being able to tell if you were being conned, lied to, or ‘taken for a ride’.  Being gullible was held with derision – on a par with stupidity or exhibiting the traits of an imbecile.  It was considered as something to ridicule; something one would have to improve upon if one was to succeed in this world.  And the solution?  To stop being so gullible and start questioning the authenticity and reliability of information.

And so it was, broadly speaking, for millennia.

Of course there were the songs, the tales, the legends and myths that came with events being recounted at court and castle, by way of messenger and the common forums, the pub and tavern, brothels and ships and on the battleground; and it was often the case that Chinese whisperers and fanciful storytellers would fantastically fabricate all manner of fables and folklore and the truth – had it even happened in the first place – would be diluted.

The popularisation of the printing press in Germany in the 15th century ushered in a new era of mass communication and yielded – along with the Renaissance – a time of vast intellectual and creative enlightenment and self-awareness.  Literacy spread like wildfire and the proliferation of great thinkers, artists and scientists is unparalleled before or since.

Propaganda reared its ugly head a few centuries later, in particular in colonial India in the 19th century.  The First and Second World Wars and the Cold War took it one step further and significantly elevated the effectiveness of the media to manipulate the truth to sway public opinion toward political favour.  The ulterior motives at play, whilst concealed to some, had many questioning the validity of what they were hearing and created what was perhaps the first generation of modern-day conspiracy theorists and free-thinkers since the Renaissance.

Cue  the arrival of the 1990s and global networking and the inauguration of the World Wide Web.  Suddenly, in just a few years, the world was abound with You Tube, memes, blogs, forums, instant-chat rooms, web pages and social media, all bursting with information for the taking.  And just like the Bubonic devastation that ravaged Europe and Asia due to the Black Death in the 14th century, an infection set in and spread to every corner of the cyber-continent – the bad information contagion caught and passed on by endless chains of online interactions that continue to this day, only inexorably more severe.

It was an inevitable occurrence of such an extreme explosion of connectivity, akin to the world existing one minute as sparse isolated villages and the next increasing to the size of modern-day China.

And the vaccine for this digital plague?  Critical thinking.

Perhaps this is being a little unfair.  Global connectivity is a truly wonderful utility that has revolutionised the way society operates.  Aside from the obvious benefits the Internet has to offer – such as e-commerce, e-mails, downloads etc. – it is also a research tool and a platform for information to propagate, making it a delicate but colossal store of [mostly] unrestricted data.  The problem of course being that anybody can share anything online – hence the information pandemic and its spread of stupidity.

“With the truth drowned in a sea of irrelevance, we’re becoming a trivial culture, more concerned with vacuous ‘selfies’, celebrity ‘tweets’ and Facebook gossip.”

Critical thinking and reasoning are skills developed in academia but not often taught in schools.  It’s the ability to question and to sift quickly through the gravel to find the gold, so to speak, and to scrutinise evidence.  It’s the act of not being gullible and believing everything you’re told.  And how do you ‘cut through the crap’ and avoid being ‘taken for a ride’?  Question everything.  Question authority.  Check the evidence.  Check the sources of information.  Don’t believe everything you read or hear.  Check for objectiveness and bias.  Research everything.  The provenance, origin or author, the authenticity, the relevance and clarity… all valuable areas for finding and digging up the useless weeds of the World Wide Web.

Just a couple of minutes scrutiny or research will separate the factual from the fabricated, the balanced from the bulls**t and the reliable from the rubbish.

Like something from Aldous Huxley’s dystopian Brave New World, or its totalitarian literary opposite number – George Orwell’s 1984 –  the world is seemingly in the infantile stages of a kind of population mind control.  Like Orwell’s oppressive and restrictive filtering of knowledge and history by The Party, we see likenesses today:  the banning of Google, Facebook, Twitter, WordPress – amongst many others – in China, and You Tube, Twitter and Soundcloud – to name but a few – in Turkey.

In the U.S. and parts of Europe, however, we see alarming similarities to the antithetical future World State portrayed by Huxley, where mass distribution of entertainment is encouraged in an attempt to pacify the people – diverting their attention away from political issues.  With the truth drowned in a sea of irrelevance, we too are becoming a trivial culture, more concerned with vacuous ‘selfies’, celebrity ‘tweets’ and Facebook gossip.

“For every time this check is performed, the plague of bad information infects one less person and the pandemic is, very gradually at least, reduced”

A more accurate comparison might be made with Lee Bradbury’s 1954 dystopian classic Fahrenheit 451 which focuses on the burning of all books, state-based censorship and the general dumbing-down, apathy and short attention-spans of the population.  While not quite as severe as Bradbury’s Firemen that are tasked with hunting down books and putting them to the flame-thrower, today’s society somewhat neglects reading books in favour of smartphone apps and social media.

So the next time you see a sensationalist news headline, a ‘factual’ meme, a pseudo-scientific article, a You Tube ‘expert’ – just question it.  Consider its validity.  For every time this check is performed, the plague of bad information infects one less person and the pandemic is, very gradually at least, reduced.  You could even, if you’re feeling really adventurous, pick up a good book – for there are many – and try losing yourself in imagination instead of traipsing through the trivial, but relentless vomit of the News Feed.

The world is a beautiful, enthralling place, unique – as far as we can tell – in the Universe.  To miss out on what it has to offer is tantamount to heresy.  Let us use the incredible technological wonder at our fingertips to enter a new era of enlightenment and knowledge – a new renaissance if you will – but in our lifetimes, in the 21st century.

View of the United Kingdom from the International Space Station, 400 km above the Earth. Image credit: André Kuipers
View of the United Kingdom from the International Space Station, 400 km above the Earth. Image credit: André Kuipers

By Chris Phoenix Clarke

Volcano apocalypse – the 5 most notorious eruptions of all time

by Chris Phoenix Clarke

Volcanoes are pretty badass, let’s be honest.  In this particular blog I’ll be reviewing 5 of the most destructive natural events in Earth’s history, caused by 3 different volcanic mechanisms: stratovolcanoes, supervolcanoes and flood basalt eruptions.

The 'Volcano Man' G Brad Lewis photographed his friend standing in front of exploding lava at the edge of the Kilauea volcano in Hawaii.
The ‘Volcano Man’ G Brad Lewis photographed his friend standing in front of exploding lava at the edge of the Kilauea volcano in Hawaii.  Image credit: G Brad Lewis/Barcroft Media.

Everyone’s typical picture of a volcano is a tall, conic mountain with a crater at the top bellowing out ash and spewing out lava (a stratovolcano – see picture of Mount Fuji below).  Unfortunately, this is no more accurate than the stereotypical view that the English all drink tea and talk like the Queen, and Australians converse solely about barbecues and drink Fosters.  

There are many different types of volcano, ranging from the picture-postcard snow-crested peak of Mount Fuji in Japan (below) to the linear fissure vents of Iceland and Hawaii.  Some explode violently sending gas and dust high into the atmosphere, whereas some seep thick lava down gently-sloping flanks (known as shield volcanoes).  Others have enormous calderas — the area of a volcano that collapses in on itself and into the empty magma chamber following an eruption, leaving an incredibly vast, open, cauldron-like hole.  Volcanoes of this type and size are usually coined supervolcanoes, but are classified officially on their VEI rating — the Volcanic Explosivity Index — a logarithmic scale with each rise of 1 corresponding to a ten-fold increase in the amount of ejected material, with the highest rating being an 8; the lowest being a zero).

Mount Fuji is a stratovolcano that is also Japan's highest mountain, situated 100 km south of Tokyo. It last erupted in 1708.
Mount Fuji is a stratovolcano that is also Japan’s highest mountain, situated 100 km south of Tokyo. It last erupted in 1708.  Image credit: AFP/Getty Images.

Some volcanoes lie patiently dormant while others have died and gone to volcano heaven (or hell, shall we say) and are extinct.  Some volcanoes can even erupt for a million years and take centre stage in the largest mass extinction event our planet has ever known: the Permian-Triassic extinction event.  Said to have wiped out 90% of all living things, this catastrophe of 250 million years ago very nearly ended life on Earth before humans had even begun to evolve.

What follows are 5-of-the-best eruptions, so to speak, but one must remember that although fascinating, volcanoes are also furnaces of death and destruction and should be regarded equally with fear and caution as with curiosity and awe.

5) Mount Tambora, 10th April 1815.  Location: Sumbawa, Indonesia.  VEI rating: 7

Officially the largest eruption in recorded history, Mount Tambora is claimed to be the only VEI-7 in almost 2000 years.  It killed in excess of 70,000 people and caused 1816 to become known as the ‘year without a summer’ due to the effect it had on North American and European weather.  The lowering of global temperatures was such that crops failed and animals died, causing widespread starvation – the worst famine of the 19th century.

This volcanic winter, as it is known, is the reduction of global temperatures as a consequence of ash particles and sulphuric acid droplets physically blocking sunlight from reaching the surface of the Earth.

The eruption was heard over 2000 km away and the ejected material (ejecta) from the volcano measured over 160 km3 .

Mount Tambora is still active to this day, but almost reaching the 200th anniversary of the catastrophe it hasn’t shown any signs of exploding again with the same magnitude.

Aerial view of Mount Tambora. Image credit: Jialiang Gao (
Aerial view of Mount Tambora. Image credit: Jialiang Gao (

4) Yellowstone caldera, 2.1 – 0.64 million years ago.  Location:  [currently] Wyoming, United States.  VEI rating: 8

Like the pits of Hell portrayed in Dante’s Inferno, here lurks a reservoir of fire and brimstone in the heartland of the United States that has been responsible for many of the largest explosive volcanic eruptions in all of history.  I am, of course, talking about the now world-renowned Yellowstone hotspot.

90% of the planet’s volcanic activity is found at the boundaries between tectonic plates; the other 10% at hotspots.

Hotspots are areas of volcanic activity at seemingly random locations across the surface of the planet that are hypothesised to be caused by anomalously super-hot parts of the underlying mantle or particularly-thin sections of the Earth’s crust (or, indeed, both).

While the hotspots do themselves appear to drift very slowly (the mantle behaves like a highly-viscous liquid over geological time), the constant, and comparatively faster, movement of the tectonic plates which make up the crust move across the hotspots — tracing out a trail of volcanic structures above and away from them.  This is evident in island chains such as Hawaii and on land from the Yellowstone hotspot trail.  As the Pacific Plate has headed in a north-westerly direction over the last few tens-of-millions of years, the magma from the hotspot has intruded through the seafloor to build up volcanic islands that rise above sea level.

Once an island is formed it is very gradually dragged away from the hotspot by the tectonic plate until it is no longer positioned above the active area.  The process continues on and another island is made in its place — repeating again and again until an island chain starts to take shape.  The main island of Hawai’i is the newest (300,000 years old) and the oldest is the island of Kaua’i (4 million years old), but the chain actually stretches away from what is termed as the state of Hawaii all the way up to the Aleutian Trench near Russia — the eroded islands there being many tens-of-millions of years old.

On land, the Yellowstone hotspot has erupted nearly 20 times in the

The trail of calderas span several U.S. states as the North American tectonic plate moves across the hotspot. Image credit: Smithsonian National Museum of Natural History
The trail of calderas span several U.S. states as the North American tectonic plate moves across the hotspot. Image credit: Smithsonian National Museum of Natural History.

last 16.5 million years, with the trail of calderas originating at the Nevada-Oregon border, going right across Idaho and finishing at its current location at the most north-westerly tip of Wyoming — in Yellowstone National Park (if only Yogi Bear was made aware of the real nature of his surroundings!).  Fast-forward a little longer and a new caldera will undoubtedly form in Montana.

Inside the national park the Yellowstone Plateau consists of 3 calderas that date back to 2.1, 1.3 and 0.64 million years ago — the first and last of these being supereruptions, and the other a very sizeable VEI-7 (getting on twice the size of the Mount Tambora eruption of 1815).  The ejecta from the two supereruptions was approximately 2,500 km3 and over 1000 km3 , respectively, making the former the second largest VEI-8 eruption of all time.

3) Krakatoa, 26th August 1883.  Location:  Sunda Strait, Indonesia.  VEI rating: 6

A photograph of an Indonesian newspaper dated one month after the eruption, showing a drawing of Krakatoa as it was before the eruption of 1883.
A photograph of an Indonesian newspaper dated one month after the cataclysm of 1883, showing a drawing of Krakatoa as it was before the eruption.

The second, but unfortunately not last, entry on our list from the Indonesian archipelago, Krakatoa is largely regarded as the most notorious eruption in recorded history.  Having claimed the title as the loudest noise ever heard by human ears and creating the biggest tsunami wave ever seen with human eyes, it also has the rather more infamous statistic of killing approximately 120,000 people (figures of 36,000 made 130 years ago are alleged to have been grossly under-estimated) — a total that is probably the most number of human fatalities ever caused by a volcanic eruption.

Having only been a VEI-6 eruption, you might be wondering why Krakatoa was so devastating.  The truth is that no one really knows.  The favoured hypotheses suggest that some form of subsidence or landslide, either above ground or submarine, allowed the mixing of sea water with the volcano’s magma chamber causing a highly energetic phreatic explosion.  Either way, two thirds of the island disappeared overnight as a result of the cataclysm.

Such was the ferocity of the main explosion that sailors in the Sunda Strait had their ear drums shattered, and the noise could be heard as far away as Australia (over 3000 km away) — a distance that is comparable to travelling between London and Moscow!

The pressure wave caused barometers the world over to go crazy and reverberated around the world 7 times; the explosion having had the energy of 2 hundred million tonnes of TNT (or 200 megatonnes) making it 12,500 times more powerful than the bomb dropped on Hiroshima and 4 times as powerful as the largest nuclear device ever detonated (the Russian Tsar Bombe in 1950).

The great 9.0 Japanese earthquake of 2011 generated tsunami waves of 10 metres. Image credit: Mainichi Shimbun/Reuters
The great 9.0 Japanese earthquake of 2011 generated tsunami waves of 10 metres. Image credit: Mainichi Shimbun/Reuters.

But the two most deadly features of the Krakatoa explosion were the tsunamis and pyroclastic flows that followed.  A pyroclastic flow is a superheated, fast-moving cloud of noxious gas and dust that incinerates and suffocates as it propagates away from a volcano, sometimes for many tens, or even hundreds, of miles.  Indeed, the one generated by Krakatoa traversed 40 km of ocean on a cushion of heated air and inundated flabbergasted natives on the island of Sumatra, killing over 1000 people.

The tsunami surges reached their peak at 40 metres — some 3 to 4 times higher than the Boxing Day tsunami of 2001 and Japanese tsunami of 2011.  Tidal gauges registered increased levels as far away as the English Channel (although some scientists claim this was due to the globally circumnavigating pressure wave).  It was the sheer immensity of the flooding that caused over 90% of the deaths from the catastrophe.

Never before has humankind played witness to oceanic destruction on such a colossal scale.  The sight must have been truly terrifying.  It is therefore understandable that Krakatoa makes it into the top 3 eruptions of all time.

2) Lake Toba,  70,000 b.c.  Location:  Sumatra, Indonesia.  VEI rating: 8

The eruption at Lake Toba (also situated in Indonesia) is widely recognised as the largest volcanic event on Earth in the last 25 million years and the largest VEI-8 of all time.  Considered supervolcanic due to its VEI rating, the explosion ejected approximately 3000 km3 of material into the atmosphere, blanketing most of southern Asia in 15 cm of ash and causing a volcanic winter that lasted for nearly a decade.  Moreover, it is postulated that global temperatures didn’t recover fully for a further 1000 years (there is geological evidence in ice cores of dramatic and catastrophic climate change during this period).

Landsat image of Lake Toba. The caldera lake is 100 km long and 30 km wide. Image credit: NASA.
Landsat image of Lake Toba. The caldera lake is 100 km long and 30 km wide. Image credit: NASA.

But possibly the most extreme part of Lake Toba’s CV is the suggested ‘human bottleneck’ that ensued.  Homo sapiens were only just beginning to get itchy feet by considering to venture out of Africa at the time, and along with the other hominids (including the Neanderthals) it made for a pretty meagre world population.  The Earth was experiencing a glacial period (between 110,000 – 15,000 years ago) so technologies such as agriculture were far from being realised and to put it simply: humans hadn’t been around long enough to populate to anything resembling considerable numbers.

After the Toba catastrophe it is estimated that less than 10,000 humans remained on the planet.  Global temperatures — already low due to the glacial period — had dropped by 3-5 °C courtesy of the volcanic winter, and in doing so created more planetary ice cover, which in turn raised the Earth’s albedo (a measure of how reflective to sunlight a surface is) — further compounding the problem.  

It is any wonder we managed to survive at all and quite scary to think we very nearly faced extinction as a species.  For this reason Lake Toba makes it to number 2 on our list.

Lake Toba as it looks today.
Lake Toba as it looks today.

1) The Siberian Traps, 250 million years ago.  Location:  [what is now] Siberia, Russia.  VEI rating: n/a

The Permian-Triassic mass extinction (or ‘The Great Dying’ as it is commonly referred to) is the single largest extinction event since the emergence of multicellular life on Earth.

Wiping out 90% of all living things, The Great Dying has often been attributed to a gargantuan asteroid impact (far larger than the one responsible for the death of the dinosaurs) or a volcanic eruption of almost incomprehensible enormity and duration.

The 'Great Dying' -- or Permian-Triassic extinction event -- is the most deadly mass extinction of life in Earth's history.
The ‘Great Dying’ — or Permian-Triassic extinction event — is the most deadly mass extinction in Earth’s history.

It just so happens that an enormous volcanic event did occur around the same time, in what is now known as Siberia, Russia (the continents had very different geography hundreds of millions of years ago) — creating the Siberian Traps.  Covering an area of 2 million square kilometres (the size of Western Europe) the Traps are evidence of an eruption so massive that it spewed out up to 4 million km3 of lava!  The Earth literally split open in a number of different places and the magma inside bled out for — wait for it — one million years.  That’s one million years in case you didn’t hear me the first time.

The word ‘traps’ is derived from the Swedish trappa (meaning stairs) and is an example of a flood basalt.  This type of event is the massive eruption of lava over a wide area of land or ocean that creates huge plateaus and mountain ranges — often layered in composition and forming ridged edges that resemble stairs or steps (see below).

The Siberian Traps. Layers of flood basalt cover an area over 2 million square kilometres.
The Siberian Traps. Layers of flood basalt cover an area over 2 million square kilometres.

It’s unclear why this event took place; the best hypothesis supposes that a meteorite impact triggered the enormous splits to open, and is also backed by [literally] solid evidence.  A number of candidate craters have been discovered — the best situated in east Antarctica.  The crater is 500 km wide and is still intact, suggesting it was formed in the last few hundred million years.  It would have also been roughly antipodal to the placement of the Traps, meaning it is at the opposite location on the other side of the Earth.  The theory is controversial at best but some scientists hold that an impact on one side of a planet can affect its antipodal location — as if the force propagates along a straight line through the centre of the Earth connecting the two.  Either way, an impact of this size would doubtless trigger tectonic unrest the world over, causing massive volcanic activity.

Whether initiated by colossal asteroid or gaping fissures in the crust, or a combination of both, The Great Dying very nearly extinguished all life on Earth.  The flood basalt of the Siberian Traps is inextricably linked with the worst extinction event in history and is without doubt the most massive example of volcanic activity on the planet.  It is for this reason that it tops the list of the most notorious eruptions ever; a real volcano apocalypse — evident in the cold, icy plateaus of northern Russia.



Monsters of the Cosmos: Black holes

by Chris Phoenix Clarke

“Now I am become Death, the destroyer of worlds” – Bhagavad Gita, Verse 32, Chapter 11

BLACK HOLES are the most terrifying, yet least understood features of the cosmos.  It is thought that a supermassive black hole — that is, one millions of times the mass of our sun — resides at the centre of every adult galaxy (including our own), and that quasars — the brightest and most distant (and, indeed, oldest) objects known in the Universe — might be the source of their turbulent creation.

I hope to take you on a journey into the heart of these mythical structures:  from violent births in the hearts of collapsing stars, to primordial beasts as old as the Universe itself; from white holes and wormholes, to escape velocities and event horizons.  Perhaps what follows might even make you question your very understanding of the fabric of reality, and indeed the Universe, itself.

So, first things first; how do they form?

To put it bluntly our Sun is a bit nondescript.  It’s a bit average.  For all its toiling fury and life-enabling radiation, the Sun is the cosmic equivalent of a vodka orange – nothing too exciting, but it’s hardly a  boring glass of soda water either.  When it dies it will quite uneventfully shed its outer layers and compress into a white dwarf star, seeing out the remainder of its days glowing gradually fainter as the aeons pass by.  Much like an ageing Guinness drinker propping up the local pub, our Sun is certainly no vomiting teenage binge drinker like its more massive counterparts.  In stark contrast, these stars getting on 15 times the mass of the Sun are simply too large to become white dwarfs and end their days in a quite spectacular fashion:  their respective cores undergoing cataclysmic implosions of truly astronomical proportions; the collapse causing the violent expulsion of each of the star’s outer layers into space, leaving behind dense and strange objects so mind-boggling it almost defies belief.

A 'feeding' black hole devouring a nearby star.
Artist’s depiction of a ‘feeding’ black hole devouring a nearby star.  Image credit: NASA

These objects are known as a stellar black holes — something that challenges our most fundamental of intuitions on the most grandest of scales.

Smaller stars undergo nuclear fusion in their cores at a much slower rate than giant stars, ensuring that they burn less brightly and live a good while longer.  The comparison of giant stars being the ‘rock gods’ of the Universe is usually a good way of looking at it.   Rather than living a life of excess and partying and possibly dying from an overdose, our Sun is the much more sedate and conservative type, blending in with the crowd and living well into the age where beige clothing is appealing.  But leaving the alcohol-related anthropomorphic analogies aside for a moment, like everything else in the Universe, stars have finite lifetimes

When stars between about 0.5 and 1.4 solar masses pop their celestial clogs they implode, leaving behind the aforementioned white dwarf star; the fatal core collapse having been halted by something known as electron degeneracy pressure*.  This is the outward pressure caused by the electrons in the core obeying a quantum mechanical rule applying to all fermions (a family of particle of which an electron is a part of) called Pauli’s exclusion principle.  It states that no two fermions with the same energy level can occupy the same space, meaning that the core can only reach a certain density before the electrons simply cannot get any closer together, for fear of treading on each other’s sub-atomic toes, so to speak.

*as a point of interest, it is worth noting that the recent supernova in galaxy M82 is thought to have been a white dwarf star that gained mass from a binary companion (another star in mutual orbit around the other).  The result was a core-collapse supernova that is currently visible in the night sky at the time of writing [25th January 2014].

Then again, when stars with cores above this critical mass (otherwise known as the Chandrasekhar limit) die, their cores initiate a collapse of such energy that each electron decides it’s ‘had quite enough of this s**t’ and attaches itself to the nearest available proton — much like a toddler clinging to their mother’s leg — to form a neutron, enabling the collapse to continue to even more compact volumes and densities.  Then, just like the electrons before, the neutrons themselves create their own outward pressure for similar reasons and the collapse is halted.  The resulting object is known as a neutron star.  So dense is this stellar remnant (the star having been well over 2 million km in diameter before,  is now just 15 km wide) that one teaspoon-full would weigh as much as mount Everest!   (see previous blog ‘Pulsars, magnetars and neutron stars‘).

Artist's impression of a supernova explosion.
Artist’s impression of a supernova explosion.  Image credit: NASA

But it’s really the heavy-set kebab munchers with cores in excess of 15 solar masses that, via their own immense gravity, crush down so violently that even the neutron pressure cannot tolerate the force, and the result of this super-sized implosion is the object known as the stellar black hole**.

**another way for a stellar black hole to form is for an existing neutron star to gain mass; to accrete matter from somewhere else.  This can be achieved in a binary star system containing a red giant star and a neutron star, for example, with the latter gravitationally ripping off streams of gas and plasma from the former –- thus increasing its mass.  If the critical mass is breached then core-collapse will start and an implosion into a black hole is inevitable.

That’s a bit racist!  Why are they called black holes?

Considering the exotic nature of these awesome monsters, they are actually quite aptly named.  Far removed from the dubiously-coined terms for the sub-atomic quark particles (such as ‘up’, ‘down’, ‘charmed’ and ‘strange’ flavours), or the way biologists seem to over complicate the naming of even the most simple of life’s processes, black holes are essentially black and do represent a cosmic hole of sorts.

According to Einstein’s seminal paper on general relativity (see previous blog: ‘Once upon a spacetime‘), space is inextricably linked with time and in the presence of gravity space is curved.  In short, this means that space and time are no longer two separate entities, but instead exist as one conjoined entity known as spacetime, and that wherever mass is found, spacetime bends in towards it.  The larger the mass, the more the curvature of the spacetime around it.  The familiar analogy of a bowling ball being placed upon a taught sheet of rubber is one way to visualise it, with the rubber bending in as the weight of the bowling ball warps the sheet.  Analogous to a marble being rolled towards the bowling ball would be the planets in orbit around the Sun.

The curvature of spacetime around a mass is the definition of gravity itself; it’s the act of ‘falling’ into this curved space that gives the illusion of a force pulling something in towards it.

Such is the curvature of spacetime, or gravity, generated by a black hole that the situation arises in which nothing can escape its attraction once ‘fallen in’ (this, the event horizon, will be explained more in a second).  Light, in all its unparalleled performance, is nigh-on fast enough to free itself, meaning that, to quote The Eagles – Hotel California: ‘you can check out any time you like, but you can never leave’, rendering the black hole forever invisible to our curious eyes.  It is, to describe it as Terry Pratchett might, so dark that it is devoid of colour; it is the blackest of all really black things***

***sometimes when a black hole is ‘feeding’, the matter being sucked in forms a super-heated accretion disc around the perimeter of the event horizon.  The process can also produce jets of radiation expelled at the poles.  This enables the black hole to have its effects on in-falling matter directly observed, but still not those within the actual black hole itself.

Okay, but what actually is a black hole?

The key ingredient to black holes is their titanic gravity .  When a supergiant star dies and undergoes core-collapse as part of a supernova explosion, what’s left is an object so compact that it’s been hitherto impossible for human minds to contemplate.  Indeed, the predictions of Einstein’s general relativity suggest that these remnants are actually infinitely dense but occupy a space of zero volume — that is, they are infinitely small.  This ‘singularity’ as it is known, is clearly counter-intuitive; how can something be infinitely dense and yet take up no space whatsoever?  Moreover, the physics break down as soon as these infinite numbers start being introduced — usually meaning some part of the theory is wrong or incomplete — and that, in fact, there is probably no singularity at all — just something we are yet to understand.

So in answer to the question ‘what is a black hole?’, and as far as is currently understood, black holes are regions of space containing an object that is infinitely dense, but occupies no volume.  It is infinitely small — a singularity.  It sounds almost retarded, but we can actually calculate the mass of a black hole by its effect on nearby gas and stars — thus defining a particular value for its mass even though the object itself has zero volume and is infinitely small!  You might well be thinking that something is amiss here — that scientists need to go back and carefully review their life choices, and you wouldn’t be the first, or indeed last, to share this opinion!

The truth is no one knows; it is simply conjecture (more on the ‘funkier’ theories later on).  One of the aims of physics in the last 100 years has been to unite our two best theories of the Universe — general relativity and quantum mechanics — to give one overriding explanation of how everything works.  We’ll then see what the mathematics has to say about black holes and their dubious singularities…

‘Event horizon’ is a 1997 film starring Laurence Fishburne, what does it have to do with black holes?

The event horizon of a black hole.
The event horizon of a black hole.  Image credit: Answers magazine

What we can establish by using Einstein’s theory of general relativity is how black holes warp, or bend, the surrounding spacetime to such an extent that nothing can escape the pull upon breaching a certain critical distance from the centre.  This radius is known as the event horizon, or Schwarzschild radius, and it is the distance at which the escape velocity of the black hole equals the speed of light.  This ‘point of no return’ at which a black hole’s escape velocity is equal to the speed of light (300,000 km per second) is easily understood by picturing a fast-flowing river that becomes ever-more difficult to paddle your kayak against, until the current becomes so great that your heroic paddling counts for naught as the kayak tumbles over the waterfall.  Analogous to the waterfall is the black hole’s event horizon.  Simply put, it is the maximum distance from the black hole’s centre inside of which an outside observer cannot see into; events inside this zone are forever unknowable****

****Stephen Hawking recently argued that the event horizon is not actually a well-defined boundary as Einstein’s general relativity would have us believe but, instead, more of a fuzzy, fluctuating area of spacetime caused by quantum effects (Nature, 2014).

Just as a rocket being launched from Earth needs to hit a certain speed to be able to counter the effects of gravity and travel into space, so too does anything encountering a black hole (if it intends to leave).  This speed is known as the escape velocity.  The gravity generated by the warping of space around the mega-dense black hole is so huge that the required escape speed is in excess of the speed of light.  This means that something would need to travel faster than the speed of light to leave the confines of a black hole, and as light by its very nature cannot travel faster than itself, this poses a problem.  What it actually does is render the inside of the black hole forever black (as light is trapped by the gravity) so no information can ever leave to hit our eyes in order to see it.

If we can’t see them, how do we know they exist?

Due to their inherent blackness it is only possible to infer a black hole’s existence indirectly, that is, the effect they have on surrounding matter, and from doing so it is also possible to determine the mass of the black hole.  The two main indications of a black hole’s existence are the speed of orbiting stars and gas around a central region of space (observed as being empty), accretion disks of orbiting material, and energetic outbursts known as radiation jets.

The G2 gas cloud will encounter our very own supermassive black hole in 2014.
The G2 gas cloud will encounter our very own supermassive black hole in 2014.  Image credit: Sunday Times

A perfect example, potentially at least, is the impending feast of Sagittarius A* — the supermassive black hole at the centre of the Milky Way.  In the coming months leading up to summer 2014, the black hole–some four million times the mass of the Sun–will play host to an incoming gas cloud three times the mass of the Earth  (BBC 2014), tugging at it gravitationally until it rips apart and becomes ‘spaghettified’ as the black hole slowly feeds and devours — dragging the head of the gas cloud inwards faster than the tail, thus causing the metaphor of elongation commonly found in Italian cuisine.  This cosmic banquet has the prospective chance to brighten Sagittarius A* by a factor of 10,000; an event unlikely to occur at such close proximities again for several hundred years, and will allow astronomers and astrophysicists to finally have some light shed on an otherwise very shadowy supermassive spectre at the heart of our very own spiral galaxy.

This event is not too dissimilar to a deep-sea oil rig setting off thousands of flare guns one-by-one in the dead of night — illuminating the  sky for miles around as the location is quite clearly  revealed.  Of course, there’s always the chance things don’t go to plan, such as the gas cloud’s trajectory being slightly off or a small wayward star masquerading behind the veils of the cloud; both possibilities potentially causing the entire mass to career past the black hole rather than being sucked in like vermicelli.  Only time will tell.

Wormholes, white holes and parallel universes

Black holes are bread and butter for science fiction advocates and inventive imaginations.  No more exotic a phenomenon could have been dreamt of, let alone one that is posited to actually be real and considered science fact.  Many wondrously wacky ideas have been exclaimed regarding the ‘insides’ of black holes, and if we’ve learnt anything in science since the days of Copernicus and Newton it’s to never discount any theory as crazy by its merits alone.  It is often said that sufficiently advanced technology is indistinguishable from magic, and the same applies for new discoveries.  No one truly knows what goes on inside a black hole, but I’ve picked perhaps the most hopeful  and altogether enticing of the current bunch of theories, namely: wormholes and white holes.

White holes are the hypothesised opposites of black holes.  They are impossible to enter and can quite happily emit light and matter into Space.  Claimants of this belief hold that at the singularity of a black hole is a white hole doing its reverse thing out into another universe.  If you imagine a sand timer — the opening funnel at the top collects all the sand and directs it down to the centre, at which point it falls out of the opening funnel at the bottom.  Analogous to this is the black hole collecting all light and matter and funnelling it into the singularity, which in actual fact is a white hole spewing it back out into another universe.  Some even go as far to say that white holes are actually the causes of ‘big bangs’, and that our universe is actually a kind of waste product from another universe’s black hole – our big bang having been caused by the associated white hole.

In the immortal words of Wayne’s World — Wayne: “No way!”, Garth: “Way!”

But 1990’s-movie shock aside, it’s no less valid an idea than current standard cosmological models stating that everything in the Universe was created at a single point.

Wormholes, or Einstein-Rosen bridges to go by their proper name, are hypothesised tunnels connecting two regions of spacetime and are an active, ongoing area of theoretical physics research.  There is much debate about what kind of wormhole could exist, but a certain type, at least, is predicted from the equations of Einstein’s general relativity (a theory that has withstood all scrutinies thrown at it, in what is now its 99th year).

Traversing the wormhole's 'throat' can be quicker than light travelling outside the wormhole.
Traversing the wormhole’s ‘throat’ can be quicker than light travelling outside the wormhole.  Image credit: Edobric

Some proponents suggest intra-universe wormholes to be a possibility — that is, tunnels connecting 2 different regions of spacetime in the same universe.  If the geometry of space is curved like many believe, it would therefore be allowable to travel faster than the speed of light, although not in the traditional sense.  It would simply be faster to traverse the wormhole from one location to the other than it would be for light to ‘go the long way around’ by travelling in the spacetime outside the wormhole.  If you imagine sprinting at maximum speed around the side of a mountain to get to the other side, someone walking through a tunnel bored through its centre could conceivably get to the other side before you did.  Of course, light travelling in the wormhole with you would always reach the other location before you did, in the same way as a sprinter running through the tunnel will always beat the person walking.

There’s all sorts of complications with these wormholes, however.  To be traversable they seem to require ‘exotic’ matter in the form of some sort of negative-energy mass in order to stabilise them, and some scientists claim that wormholes can only exist in one direction in the singularities of black holes.  The latter would only bring you out into another region of spacetime inside a different black hole, meaning that you could never escape out past the event horizon in this new region.

The quantum-mechanical "Schrödinger's cat" paradox according to the many-worlds interpretation. In this interpretation, every event is a branch point; the cat is both alive and dead, even before the box is opened, but the "alive" and "dead" cats are in different branches of the universe, both of which are equally real, but which do not interact with each other.
The quantum-mechanical “Schrödinger’s cat” paradox according to the many-worlds interpretation. In this interpretation, every event is a branch point; the cat is both alive and dead, even before the box is opened, but the “alive” and “dead” cats are in different branches of the universe, both of which are equally real, but which do not interact with each other.  Image credit: Christian Schirm

Perhaps a more compelling argument is that of inter-universe wormholes.  These wormholes actually bring the traveller out into another region of spacetime in a parallel universe, resolving certain paradoxes which may arise in intra-universe wormholes, such as time travel and causality violations (the traveller would be brought out into a separate universe that doesn’t interact with the first, so they would never run into said paradoxes).  This theory is an interpretation of quantum mechanics, whereby reality is more like a tree of many branches, where every possible outcome does happen and there is an infinite number of parallel universes.  Standard quantum mechanics (I say standard; there is absolutely nothing orthodox about quantum theory!) uses something called a wavefunction collapse which asserts that before something is observed every outcome is possible, until collapsing into just one reality the moment it is observed.  Schrödinger’s cat being the usual analogy to use at this point, but I’ll refrain from delving any deeper into quantum mechanics here (see picture above).

Quasars and supermassive black holes

Finally we get to the real monsters of the cosmos: supermassive black holes.  It is hard to fathom just how powerful, how huge and how destructive these leviathans of space really are.  It is consensus amongst physicists that one lies at the centre of every adult galaxy and that the formation of these giants is down to the brightest phenomena in the Universe: quasars.

Supermassive black holes range in the order of  a hundred-thousand to a a few-billion times the mass of the Sun, whereas stellar black holes are classified as forming from stars up to about 30 times the mass of the Sun.  Intermediate black holes, as they are known, are strangely lacking from our observations of the cosmos which suggests that the formation of supermassive black holes is fundamentally different to that of stellar black holes.

It is worth mentioning at this point that evidence of supermassive black holes has been observed in the very early universe, implying that their creation is something that occurred during the first generation of galaxies.  Some theories assert that newly-forming galaxies are turbulent and chaotic places and that existing stellar black holes are constantly fed and grow to larger, more intermediate sizes.  They then encounter other black holes doing the same and a kind of cannibalistic black-hole chain-reaction occurs, eventually going on to form one colossal supermassive black hole at the centre of the galaxy.  This cannibal-esque feeding frenzy forms what is known as a quasar — an active galactic nucleus that takes the form of enormous jets of energy being emitted from the edges of the supermassive hole’s event horizon as an orbiting accretion disc of stars, gas and other black holes is fed into the monster’s mouth.

Quasars seem to have been a feature of almost all newly-forming galaxies during the first generation in the early universe.  They are therefore some of the oldest detectable sources of light we have observed — which also make them the most distant.  Such is the energy output of a quasar that it is possible to observe one 28 billion light years away!

Another theory puts forward the existence of primordial supermassive black holes — those that formed as a direct consequence of the extreme pressures of the Big Bang, and would explain the origins of supermassive black holes at the centres of the first galaxies.

So one might say, if some of the previously-stated theories are combined, that a black hole in another universe created a white hole in our Universe (the Big Bang) which, in turn, created the primordial supermassive black holes of the first galaxies.  These eerily-enormous galactic engines allowed for the continued evolution of stars which, themselves, lived out their lives to eventually collapse into stellar black holes.  And so the grand black-hole recycling system goes on and on…  One might even say that black holes are the fundamental mechanism by which our Universe (and, potentially, an infinite amount of other universes) is built upon, and without which, there would be no Universe to reside inside so we could sit here and ponder their importance in the first place.

So it seems that stellar black holes are as ubiquitous in the Universe as they are unusual and, although related in a sense to supermassive black holes, form very differently to their monstrous big brothers.  These celestial older siblings are likely found at the centre of every known galaxy and are perhaps key to the Universe’s evolution and continued survival.  Whatever really lurks in these regions of dark space, whether complicit with current theory or not, will doubtless be, at the very least, just as exotic as the limitations of our intelligence have allowed us to imagine.

Written by Chris Phoenix Clarke, January 2014.


Clarke C.W., 2014. Space City. Available at [accessed 29th January 2014]

Nature, 2014. Stephen Hawking ‘There are no black holes’. Available at [Accessed 29th January 2014]

BBC, 2014. Black hole’s ‘big meal’ could spark fireworks. Available at [accessed 29th January 2014]

The trouble with string theory

by Chris Phoenix Clarke


Whether you’ve looked into it or not, it’s probably true to say that you have at least heard of string theory.  It’s strange, a bit crazy, and challenges our intuitions on the most basic of levels – just like a good physical theory should do.  It comprises a number of slightly altered versions — collectively known as ‘superstring theory’ — but all ultimately deal with the same fundamental principles.

The need for a theory such as this is down to the complete and utter incompatibility of our two current best theories that describe the Universe: Einstein’s revolutionary paper on general relativity and the mind-bending theory of quantum mechanics.  Both do fantastically well at describing and predicting their respective scales (general relativity for things we can see; quantum mechanics for the sub-atomic world), but both are useless when combined together to attempt to describe everything.  This, of course, means that both theories are incomplete, and to some extent, wrong.  What string theory, and other concepts like it, try to do is explain everything in just one single overriding theory.

String theory

String theory is based on the idea that every particle in the Universe is composed of unimaginably tiny vibrating strands of energy — or strings — and the frequency of which determine the type of particles that exist.  Much like piano keys playing certain allowed notes, these strings can only vibrate at certain ‘harmonics’, with each harmonic corresponding to a different type of elementary particle.

Now this is all well and good – it is certainly an elegant and compelling theory.  However, the maths doesn’t work.  That is, unless you introduce 10 dimensions into the mix.  Once you use 10 (yes, TEN) dimensions, the equations work perfectly and generate all the correct values for things like the mass of an electron (that, without the dimensional additions, came out wrong before).

But this is the inherent problem with string theory: the introduction of a further 6 dimensions more than we are used to in our every day lives.  How can there be more than up/down, forwards/backwards, left/right, plus one dimension of time?  These 3 spatial dimensions encompass everything around us, to suggest there can be a further 6 is tantamount to hallucinogenic drug use and requires a leap of faith more associated with religious types than scientists!

There is also the slightly convenient snag in string theory, so to speak – it can’t be disproved.  The cardinal ingredients — the minute strings of vibrating energy — are so small that they are billions upon billions of times smaller than protons, neutrons and electrons (on a scale known as the Planck length, or 10−35 m), and are likely to be veiled from view forever.  The theory is also unable (at its current state) to make any testable predictions about the Universe.

So an elegant theory, yes; but one with enormous hurdles to overcome if it is to be taken seriously. Introducing 6 additional dimensions and claiming that resonating strings (that can never be seen) populate every particle in the Universe without some sort of evidence other than complex mathematics is asking a lot from even the most open of scientific minds, but we must remember that Copernicus and Einstein started down roads quite similar to this one…

The ant on the telephone pole

The analogy often used to entice people into the extra-dimensional viewpoint of string theory is one of ants on telephone cables.  Imagine you are in a third-storey flat, looking out of a window at a distant telephone pole.  From your frame of reference you see the pole and the telephone cables running out into the various buildings, and if you didn’t know any better you’d say that the pole appears as a flat brown object and the cables as thin black lines, both obviously appearing from your distance, respectively, as 2-D and 1-D objects (you can see the movement up/down and left/right is possible on the pole, but you can’t infer that forwards/back is an option.  And the cable is so thin from your vantage point that you can only assume that left/right movement is possible.)  Now zoom in and imagine yourself as an ant climbing the telephone pole and scurrying around the cables; from this frame of reference the cables appear anything but 1-D, they are very much round and the ant can move along in all 3 dimensions.

The point of this analogy, then, is to show that if something is small enough then it can easily go unnoticed.  Moreover, something can appear to be very different from how it really is — simply from not being observed in enough detail — and such might be the case with the proclamations of string theory; dimensions so small that we can never notice them.  Whereas our 4-dimensional universe is suggested to be ‘flat’, these other dimensions are proposed to be curved and form tiny loops.

This is a very hard concept to grasp, even for just one extra spatial dimension.  But to visualise another 6 is likely to make one’s brain explode.  This again addresses an intrinsic flaw, if you like, with the human species.  I think it might have been Richard Dawkins who quipped — possibly in reference to another author —  ‘We evolved to avoid lions on the Great Plains of Africa; we didn’t evolve to do quantum physics’.  Our deep-rooted common sense is perhaps the greatest limitation of our understanding of the Universe; our brains aren’t built to comprehend such distinctly counter-intuitive and bizarre concepts.

“We evolved to avoid lions on the Great Plains of Africa; we didn’t evolve to do quantum physics”

To simply dismiss the wacky claims of string theory is to be foolish and somewhat naive; it is very possible that there could be more ‘space’ to the Universe other than up/down, left/right and forwards/backwards, we just find it excruciatingly difficult to visualise.  It wasn’t so long ago that Ernest Rutherford proved the existence of atomic nuclei, and Arthur Compton the electron.  More recently the discovery of quarks, dark matter and dark energy.  All seemed silly, strange and unlikely before they were proved, and yet how strange or silly does the idea of an electron seem in the twenty-first century?  Arthur C. Clarke wrote that ‘Any sufficiently advanced technology is indistinguishable from magic’, and this same line of reasoning can be applied to physical theories, in the sense that concepts so strange do seem indistinguishable from make-believe at first glance.

The trouble with string theory, then, is the task of accepting these extra dimensions.  Thought experiments often help with visualising scientific ideas, but I can’t help but feel the one about the ant doesn’t really suffice.  After all, whether or not we are too far away to safely say a distant object is 3-dimensional, it is still just 3-dimensional.  The cable doesn’t behave any differently than anything in the overlooking flat – it still operates in the same 3 dimensions as we do.  Yes, the ant has more of a claim to this realisation than us, but all that it proves is that there is greater detail the smaller something gets (and the associated observational blindness one has when one is much larger!).


Perhaps more effective would be Edwin A. Abbott’s 1884 novel Flatland.  In the story the world is 2-D, existing on what is akin to a flat piece of paper.  Everything on this 2-dimensional world can move either forwards/back and/or side-to-side, but cannot move up/down (much like a graph drawn on some A4 paper displaying the X- and Y-axes; the same sheet of paper cannot literally show the Z-axis which effectively would rise right out of the paper and into the air).  Now imagine that a 3-D object — such as a ball — somehow descended upon Flatland and passed completely through it.  From the frame of reference of someone confined within the limitations of this 2-D world they would notice a small line materialise out of nowhere (as the bottom of the ball began to penetrate through) that gets progressively longer (as the ball nears halfway) and then progressively smaller again (as the other half of the ball goes through) before finally disappearing.

This would be a very mystifying experience indeed for a resident of Flatland – their comprehension of space is limited to the 2 dimensions they exist in.  To suggest there is a third would be too much for them to understand, and even by demonstrating a 3-dimensional object results in a 2-dimensional translation.  The only way for a ‘flatlander’ to grasp 3 dimensions would be to lift them out of 2 dimensions and into 3, and showing them the ball passing through Flatland.  Analogous to this are humans not being able to appreciate further spatial dimensions whilst existing in the 3 we can comprehend – so programmed are we to see and process our world in 3 dimensions that contemplating any more defies every ounce of common sense that we possess.

A 'calabi-Yau' shape. A proposed arrangement of the extra dimensions that warp the strings into their allowed harmonic frequencies. Image credit: Brian Greene
A ‘Calabi-Yau’ shape. A proposed arrangement of the extra dimensions that warp the strings into their allowed harmonic frequencies. Image credit: Brian Greene

If we have learned one thing from dark matter, dark energy, and quantum mechanics it is not to discount something based solely on how odd and outlandish it is.  This isn’t to say that the necessary extra dimensions of string theory are real, far from it, but it is this willingness to think outside the box that has spawned many of the greatest scientific achievements.  Had the ancient Greeks not argued that the Earth could be spherical, Eratosthenes might never have made his calculations to estimate its circumference and Magellan might never have proved it by circumnavigating the planet.  Had Copernicus not announced the heretical notion that the Sun did not go round the Earth — but in fact was the exact opposite — Galileo and Newton might never have made their respective breakthroughs in astronomy and physics.  Maxwell’s work on electromagnetic fields; Einstein’s special and general theories of relativity; the spooky reality-defying quantum theory as developed by Heisenberg, Schrödinger and Bohr (amongst many others) – all required brave steps into the unknown and were initially met with scepticism and, quite often, ridicule from others that understandably felt threatened by the strangeness and scope of that which at first appeared so extraordinary.

by Chris Phoenix Clarke

Star profile: Betelgeuse

by Chris Phoenix Clarke

Betelgeuse (pronounced ‘betel-jers’) is a red supergiant star around 640 light years away in the constellation of Orion. It is nearly 1000 times larger than the Sun and 20 times more massive; it’s diameter alone would be enough to engulf Mercury, Venus, Earth and Mars and would reach the orbit of Jupiter.

Betelgeuse, as compared to our Sun.
Betelgeuse, as compared to our Sun.

The star is in the final stages of its lifecycle and is expected to go supernova any time between now and the next million years. Upon doing so, Betelgeuse–or at the very least the light from the explosion–will outshine the full Moon and be clearly visible in broad daylight.  Due to the distance involved it is quite possible that Betelguese has already exploded, but we wouldn’t know about it until the light had completed its 640 year journey to Earth!

Doomsayers in 2012 claimed the ensuing gamma-ray burst from the supernova could result in the end of the world, but due the the star’s axis of rotation being tilted away from the Earth this almost certainly debunks the claims.

All that will be left of Betelguese after its impending supernova is a star remnant known as a neutron star. Approximately 20 km in diameter, the neutron star will still weigh more than our own sun and spin incredibly fast – some do in excess of 100 times per second! It is even possible the resulting remnant will be a pulsar neutron star, emitting regular pulses of electromagnetic radiation from the polar regions for many thousands of years (and with such alarming regularity that the pulses might only go out of sync by 3 milliseconds per million years!).

Betelgeuse is clearly visible to the naked eye as a bright red star (it is actually the 8th brightest in the night sky). If you face south and look to the right just after dark, Betelgeuse is the top-left star in Orion (the hunter constellation that resembles a man shooting a bow).

For more information about neutron stars please visit:

Written by Chris Phoenix Clarke

4 reasons why astrology is bollocks

by Chris Phoenix Clarke

“I don’t believe in astrology; I’m a Sagittarius and we’re skeptical.”

– Arthur C. Clarke

night skyMan has always been curious about the night sky.  I sometimes picture our distant ancestors roaming through Africa’s Great Rift Valley, gazing up on a clear summer’s night and becoming awash with marvel and wonder at the tapestry laid out above them; much in the same way as I experienced as an awestruck child echoing the sentiments unquestionably felt by Copernicus, Galileo and Newton just a few centuries before.  Never has there been more justifiable a spectacle as unanimously admired throughout human history than the ethereal  magnificence of a starry night sky.

But contrary to what the rather crude title of this blog suggests, it is not with too much ridicule that I refute astrology; I think if more people took the time to look upwards instead of inwards we wouldn’t have half the triviality and petty squabbles we are surrounded by in our every day lives.  I can see how the grandeur of the heavens can be spellbinding enough to trigger belief in a connection between us and the stars, but what was once a genuine search for the meaning of human existence has mutated into a money-making industry based entirely on non-scientific speculation that preys on the vulnerability, insecurity and curiosity of millions of people the world over.

Some may assert an honest interest and/or legitimate pursuit of the ‘science’ of astrology, but I can only assume that what they’re really laying claim to is a deluded kind of hobby, a pseudo-science at best.  Science is the method in which testable predictions can be made about the Universe; to date, not a single one has ever happened by way of astrology.

*DISCLAIMER* Before I begin I want to make it abundantly clear that I realise astrology has many furrows and off-shoots, and I don’t claim to have researched each and every astrological avenue; this blog is merely a broad look at the core principles involved and how they withstand to scientific scrutiny.  I’m sure many astrologers will denounce the credibility of other astrologers’ methods (and visa versa) but rather than pursue semantics, I am addressing the fundamental assumptions on which astrology is founded and why, in my opinion, they lack any shred of validity in today’s society.  If this causes offence, well perhaps you should have seen it in your tabloid horoscopes/tarot cards/tea leaves that a tall, dark stranger would appear and insult your mystical beliefs – in which case you really shouldn’t be very surprised, or indeed offended by, this blog in the slightest.

#1 – What force connects us?

Astrology, in its broadest sense, uses the positions of planets and stars at the time of our birth to predict future events in our lives.  This implies that the planets and stars somehow affect us, physically, in such a way that their position relative to each other (and indeed, us) at the time of our birth has a very real — and more importantly, tangible —  influence over what will happen in our futures.

A physical connection means a force must exist.

The Universe as we know it is composed of 4 fundamental forces: the strong and weak nuclear forces, which act only at very short distances and govern the interactions between subatomic particles and atomic nuclei; electromagnetism, which acts between electrically charged particles, and gravitation, which acts between masses.  Absolutely everything we know of in the entire Universe happens because of one or a combination of these 4 forces at work, and we understand them well enough to send rockets to the Moon, supply electricity to homes, create medicines and technology, and blow up entire Japanese cities.  This doesn’t go as far to say we know everything there is to know, but from the inexorably vast leaps in scientific knowledge through the ages we can safely say we have capitalised on what we do know, and heroic feats have been accomplished by those endeavouring to seek and discover new and unfamiliar advancements of mankind.  So for those that decree an ‘unknown’ force as the puppeteer of astrology I say this: if science, in all its rigour and tenacity, knows nothing of this force by now, then I can assure you that practitioners of astrology know even less.

It seems only logical then to discount the nuclear forces, due to their inherent proximity limitations, and concentrate instead on gravity and electromagnetism as possible candidates for the mystery force of astrology.

If the supposed connection between us and the planets was down to gravity, then due its own definition the gravity experienced between a human and a planet would be proportional to the two masses involved and inversely proportional to the square of the distance between them.  This means that both mass and distance are defining characteristics of the ‘force’ of gravity (Newton proposed gravity as a force; Einstein later postulated that gravity is simply the act of falling into the curved spacetime caused by a massive object – see a previous blog ‘Once upon a spacetime).

This raises two very important points: 1) if gravity is the force used by the workings of astrology then any object of mass will affect the predictions; moreover, the larger the object, the larger the force of gravity.  2) the distance between an object and the Earth is also vitally important; the further away something is the less ‘pull’ of gravity it exerts.  The implications are therefore very clear; objects with more gravity in relation to the Earth exert a higher force, meaning they should have more influence in astrological terms.

However, as will become repetitively apparent, this couldn’t be further from the truth.

Jupiter, for example, holds no more sway than Saturn even though it is much nearer and far larger.  Diminutive Pluto, barely even two-thirds the size of our moon, has no less say-so than Mercury even though it is a few billion miles further away from the Earth.  Seemingly exempt are also the various moons, other dwarf planets, and asteroids of the Solar System; indeed, two moons outsize the planet Mercury and a further five outsize Pluto.  The dwarf planets Eris and Makemake are comparable to that of Pluto and there are many other TNOs (trans-Neptunian objects) well over two hundred miles in diameter, usually found in a region known as the Kuiper Belt (a vast reservoir of asteroids, similar to the asteroid belt between Mars and Jupiter, but found much farther out past Neptune).

Solar system objects to scale
Solar system objects to scale
The main planets and dwarf planets to scale
The main planets and dwarf planets to scale

So knowing what we do about gravity, it does beg one glaringly obvious rhetoric: surely the Moon, being as massive and as close as it is, would have the only influence over our lives?  The other planets (somewhat larger than the Moon, granted, but are so much further away than they are more massive) exert next to no gravity in comparison, so how would they have any influence whatsoever over our lives when pitted against the huge rock on our cosmic doorstep?  It’s like saying a lit match several fields away has equally as likely a  chance to burn you as the raging bonfire you are swigging your cider next to.

One might go so far as to say that the actual planet we reside upon exerts more gravity than anything else; the very fact we remain rooted to the spot as the Earth spins at 1000 kph attests to it, and yet the colossal mass directly in contact with our feet has about as much input into astrological predictions as a penguin does in an avalanche.

Of course the real nail in the coffin for gravity being the solution to astrology is its inherent weakness when compared with the other three forces.  It is so much weaker, in fact, that a simple fridge magnet can beat the entire Earth in a tug-of-war with a paper clip.  Not even the whole of the Earth’s mass, pulling at the paper clip gravitationally, can stop the humble magnet from picking it up.  This shows just how superior electromagnetism is as a force when compared to the strength of gravity.  To suggest the planets can gravitationally affect our futures due to conditions set when we were born is, quite simply, barking ludicrous.

So what about electromagnetism then?  The problem with this theory is that electromagnetism deals with the interaction of electrically-charged particles, either in the form of electric or magnetic fields, and because of the composition of the various planets, not all have electric or magnetic fields – they can be neutral.  All the planets would need to be equally ‘charged’ for any astrological predictions to be made and as far as is known to science — and more importantly, astrologers — this just isn’t so.

In any case, by far the largest emitter of anything electromagnetic is the Sun itself.  Making up over 99% of all the mass in the Solar System, the Sun dwarfs anything else in the neighbourhood and if electromagnetism is the source of astrology’s mysterious force, then any and all predictions about our futures would only deal with the Sun and nothing else (to do otherwise would be akin to thinking that spilling a glass of water during a tsunami made a noticeable difference).  Again, this is not so in astrology.

#2 – why some ‘planets’ and not others?

There are more than just 9 (pardon, 8) planets.  Pluto’s declassification as a ‘proper’ planet was bad enough for astrologers, but since then many other Solar System objects, comparable in size, have been discovered, with undoubtedly many more on the cards.  Unless astrologers grant some special pass to the main 8 planets, why should they be dealt with any differently to any other object orbiting the Sun?

We already established that gravity – or more precisely, mass and distance – cannot figure in astrology, and this isn’t an opinion; this is according to astrologers themselves and the way they treat each planet equally when formulating predictions.  So by their own admissions, astrology cannot be based in gravity.

So if mass and distance are redundant and the only factor of importance is proper classification as a planet, then what do we do about the hundreds of new planets that have been discovered orbiting other stars in our galaxy?  Distance clearly plays no part, and these newly discovered planets are proper planets, so why shouldn’t they figure?

#3 – The falsifiability of star sign astrology

If science has been dropping bombs on ignorance, stupidity and mumbo-jumbo over the last few centuries, then the one about every person on the planet being the wrong star sign has got to be up there with other great explosions of scientific sanity such as carbon dating and the Earth being spherical.  Yes, when I first heard this it amused me too.  The fact that there are actually 13 signs in the zodiac only added more sprinkles to an otherwise already very tasty slice of cosmic in-your-face cake, which I shall now explain.

There are 3 critically-essential problems with the branch of astrology commonly found in newspapers and magazines.  Star sign astrology, or horoscopes, deal with the apparent position of the Sun relative to a set of constellations when someone is born (otherwise known as the zodiac).  They claim that being a particular star sign assigns someone particular and specific traits about their personality, and allows for the determination of certain future events in their lives – usually days, weeks or months in advance.

The first problem is that of axial precession.  If the Earth was perfectly spherical all the time then it would spin about its axis and demonstrate no ‘wobble’ whatsoever – kind of like the wheel of a new car as it spins around the axle.  But due to the Earth bulging slightly at the equator and the fact that the Sun, Moon, and other planets tug at it gravitationally, the spin becomes ever so slightly offset and over the course of approximately 26,000 years the Earth’s north direction traces out a complete, but small, circle in the night sky.  Analogous to this would be a spinning top when slightly off-balance; the toy would begin to wobble away from dead-upright and trace a small circular motion about the centre (but of course spinning tops obey friction laws and the Earth’s gravity, and so the circle becomes larger and larger until it topples over).

This means, many years from now, that Polaris (the North Star) will no longer be our northern reference point in the sky; instead it will move towards the stars Deneb and then Vega, before returning once more to Polaris (see animation below).  This precession causes the apparent position of the Sun against the backdrop of the constellations to move over time, meaning that the Sun will not always be in the same sign of the zodiac at the same time each year.  Furthermore, over the course of 26,000 years the Sun actually regresses through each one of the zodiac constellations until it is back where it started, meaning that astrology’s dependence on the position of the Sun relative to the stars is complete and utter nonsense.

This stellar regression has resulted in star signs shifting forwards in the year by about a month since the zodiac was conceived 2000 years ago, so pretty much everyone alive is now a different star sign; Cancers are now Gemini, Capricorns are Sagittarius  and so on and so forth.  Those born in the first half of December might be intrigued to know that they are actually Ophiuchus, the ’13th’ sign of the zodiac.  Left out by astrologers in favour of only wanting a collection of 12 star signs, Ophiuchus is evident in the sky for all to see but is seldom spoke of, lest known or accepted, by astrologers and the general public alike.  Just another example of astrology cherry-picking and ignoring the evidence put forward by astronomers.

Axial precession
Axial precession

The second problem concerns the movement of the stars over time.  All stars in the Universe career through space at astonishing speeds, bound by the force of gravity as they orbit the centre of mass at the centre of their respective galaxies.  Stars in our own galaxy–the Milky Way–are not fixed relative to the Earth.  They are moving relative to us and we are moving relative to them; it only seems like the stars are continuously found in the same place each year because of the immense distances involved.  You only have to look out from the beach to a small boat on the horizon to see that it appears to barely move.  It gives the illusion of staying still even when crashing through the waves at a given rate of knots.  After a short while you might notice a small degree of movement to the left or right, and this is analogous to the astronomical time it would take for a star many light years away to appear to have moved in the sky at a given rate of tens of thousands of miles an hour!  Every single one of the constellations we see now looked completely different to the dinosaurs and will look completely different in the future, thus rendering star-sign astrology and its dependence on the zodiac totally falsifiable.

Thirdly, a process known as cognitive bias can occur because of the vague and highly ambiguous predictions of star-sign astrology.  A bit like television weather forecasts, the outlook for a given region can only be honed-down to the precision of ‘widespread gales with a chance of rain’, or ‘patches of cloud’ and ‘sunny spells’.  The same is evident in all horoscopes ever written.  ‘Your luck will turn’, ‘beware of financial problems, ‘you will meet someone who does something’ are all common ‘predictions’ of horoscopes and yet they are so vague it is any wonder why people take the slightest notice.  The deliberate ambiguity only heightens the inherent lack of legitimacy.  Cognitive bias is the process by which people act upon what they have heard.  So in other words, after hearing they might be lucky or make some money, or meet someone, they will subconsciously go out of their way to make it happen.  This might take the form of taking more chances to become lucky, or deciding to go to a nightclub after all, thus increasing the chances of ‘acting out’ their horoscope.  This applies to the traits assigned to their star sign too; an individual who is a Cancer might grow to fit their profile as outlined by astrology because they subconsciously think it’s the way they are meant to act.

There is also one strikingly obvious flaw with star-sign astrology.  Assuming that statistical averages hold true (and they always do when dealing with large numbers) this means that roughly an even amount of people are born into each star sign, meaning that if we divide all the 7 billion people of this planet into the 12 [accepted] signs of the zodiac, there will be over 580 million people with the same star sign as you.  Suggesting that my weekly horoscope in the Daily Mail applies to 580 million other people makes the prediction of me coming into financial success that little bit less fortunate (not to mention economically unlikely!).  Also there are only so many tall, dark and handsome strangers on this planet!

Finally, if astrologers choose to ignore axial precession and the movement of distant stars, they cannot dispute that each orbit of the Earth around the Sun does not bring it back to exactly the same spot.  On average, the Earth is 44,000 miles further away each year, implying that someone born on the same day as you the following year would not have been in the same position as you were in relation to the Sun.  Again, this throws the validity of astrology right out the laboratory window.

#4 – Consistency, consistency, consistency!

If a mysterious force as of yet known to science–but somehow understood and utilised by astrologers–really does exist between humans and the stars, then proof would be in the planetary pudding, so to speak.  This would take the form of a certain level of consistency between predictions made by astrology as a whole; and yet there is not one slice of this pudding anywhere to be seen.  In fact, some statistical tests have debunked the claims of astrology so heavily that it’s been stated that pure chance has, in many instances, been more consistent than astrological predictions (Dean and Kelly, 2003).  And that doesn’t even make mathematical sense!

You only have to compare weekly horoscopes between various magazines, newspapers and television shows to see the inconsistencies.

Astrology, clearly and indisputably debunked.

It is often said that recollections of certain memories are finite, that experiences you thought inexhaustible at the time are actually more precious than you know.  Included in this I would undoubtedly put the memory of a crystal-clear, star-filled panoramic view of the night sky.  I’m sure as children  most of us spent some time peering upwards after dark with all sorts of questions about the Cosmos reeling through our curious brains.  But when was the last time, post-childhood, we remembered such an experience?  I know a certain percentage of you will recall — probably with a certain nostalgic fondness — a time spent with friends outside on a clear night, lying on some grass, gazing up at the stars and trying to differentiate between planes, shooting stars and UFOs, but how long ago was it?  And more importantly, how many times will you ever experience it again?  Is it inconceivable then, in the most regrettable of ways, that this particular childhood memory might be the last, or indeed only, time you’ve ever spent really appreciating the starry night sky?  How long before the memory fades into obscurity and is lost forever?

What is now and what was surely a glittering display of celestial magnificence in the times of our first ancestors, the stars are rightly a spectacle to be cherished and used as a catalyst for imagination and discovery.  There is absolutely no need to conjure an imaginary bond between us and these amazing objects, much like the unnecessary invention of gods we seem to require to assign meaning to our lives.  It should be enough that we are able to bear witness to the view, and as science delves deeper into the mysteries of the Cosmos, so too do we learn more about the Universe in which we live, and ultimately about ourselves in the process.

Written by Chris Phoenix Clarke

What looks like a star-filled sky is actually the Hubble telescope's most distant image ever recorded. Each point of light is an entire galaxy, formed in the early universe!
What looks like a star-filled sky is actually the Hubble telescope’s most distant image ever recorded. Each point of light is an entire galaxy, formed in the early universe!


Dean, G., Kelly, I.W., 2003. Is Astrology Relevant to Conciousness and Psi? Available at

The Christian Science Monitor, 2011. Why astrology is even sillier than we thought. Available at

 Wikipedia, 2012. Axial precession. Available at

Astrophysics graduate blogging about the Universe