Skip to main content

The Sun is Dying and Global Dimming – Brian Cox

Two mini-features from the CERN physicist, media star and scientific advisor to the movie Sunshine.
The Sun is Dying
The Sun will not live forever. It has enough fuel left, if our current understanding is correct, for another 5 billion years, at which point it will die. But could it be possible for the Sun to die much sooner, within the next 100 years even? From a scientific perspective, it should be said that this is very unlikely. But, it is also true that there is a lot about the universe that we do not understand.
Over the last few years astronomers have observed that there is extra “stuff” in the universe that we can see only by its gravitational influence on stars and galaxies. This stuff goes by the name of Dark Matter, and there is five times as much Dark Matter in the universe as there is normal matter, the stuff that makes up you, me, and the stars and planets we can see with our telescopes. What is this mysterious stuff? It’s possible, some scientists would say likely even, that this stuff is made of particles known as supersymmetric particles, a new and exotic form of matter that is high on the list of potential discoveries at CERN’s giant Large Hadron Collider, a 27km in circumference machine which begins operations this year after almost a decade of construction.
Theoretical physicists have spent many years calculating the properties of these supersymmetric particles, and we have a reasonable theoretical understanding of how they might behave. One possibility is that they could clump together into giant balls known as Q-balls. If this is true, then these heavy and exotic objects could have been made billionths of a second after our Universe began, and still be roaming the Universe today. It is speculated that, if a Q-ball drifts into the heart of a super-dense object such as a neutron star, it could begin to eat away at it’s core like a cancer, until the star is no longer massive enough to maintain itself and explodes in a violent explosion. Such explosions, known as gamma ray bursts, are seen in the Universe, although their cause is as yet unknown.
Could such a dangerous, exotic object drift into the Sun’s core and cause it to stop shining? It is likely that the Sun is many times too diffuse to stop a Q-ball – it would power right through. But maybe, just maybe, some strange exotic form of matter from the earliest times in the universe could settle deep within the Sun’s core, and disrupt its function enough to cause the catastrophic scenario seen in Sunshine. It’s far-fetched, but we have a saying in physics that anything that isn’t explicitly ruled out is therefore possible, so in the final analysis, you never quite know.
Global Dimming
It is now suspected that pollution in the Earth’s atmosphere, caused by industrialization and natural phenomena such as volcanic eruptions, may have significantly reduced that amount of sunlight reaching the Earth’s surface. It is estimated that this could have led to a cooling effect of over 1 degree overt he last 40 years, which would go some way to offsetting the effect of global warming. Global warming is caused primarily by increasing carbon dioxide levels in the atmosphere that prevent heat being radiated back out into space from the Earth’s surface.
The phenomenon of global dimming may therefore have saved us, so far, from the worst affects of climate change, although it has been noticed that as pollution levels have been reduced, particularly in Western Europe, the affects of global dimming seem to be reducing, leading to an accelerating temperature rise once again. We may therefore be in the paradoxical situation that reducing pollution might INCREASE the effects of global warming, leading us ever more quickly towards catastrophe.
This discovery isn’t all bad, however, because it may suggest a short term solution to climate change. Why not intentionally put pollutants, which may be designed to be benign in other respects, into the atmosphere to accelerate global dimming, and therefore slow the climate change caused by carbon dioxide emissions. Several suggestions along these lines have been made, including adding small particles to airplane fuel, and therefore using one of the main contributors to climate change, aircraft, to slow its effects. It’s an intriguing possibility, and one that is the focus of significant research, although it should be said that we cannot at present predict the effects of such fine-tuning of the climate, so global dimming shouldn’t be seen as a means to allow us to continue to increase carbon dioxide emissions.
Brian Cox is science advisor to the movie Sunshine – see


Popular posts from this blog

The Dialogues - Clifford Johnson ***

The authors of science books are always trying to find new ways to get the message across to their audiences. In Dialogues, Clifford Johnson combines a very modern technique - the graphic novel or comic strip - with an approach that goes back to Ancient Greece - using a dialogue to add life to what might seem a dry message.

We have seen the comic strip approach trying to put across quite detailed science before in Mysteries of the Quantum Universe. As with that book, Dialogues manages to cover a fair amount of actual physics, but I still feel that the medium just wastes vast acres of page to say very little at all. This is brought home here because quite a lot of the sections of Dialogues start with several pages with no text on at all, just setting up the scenario.

As for using a discussion between two people to put a message across, Johnson makes the point that, for instance, Galileo's very readable masterpiece Two New Sciences is in the form of a dialogue (more accurately a discu…

On the Moor - Richard Carter ****

There's much to enjoy in Richard Carter's pean to the frugal yet visceral delights of being one with England's Pennine moorland. If this were all there were to the book it would have made a good nature read, but Carter cleverly weaves in science at every opportunity, whether it's inspired by direct observations of birds and animals and plants - I confess I was ignorant of the peregrine falcon's 200 mile per hour dive - or spinning off from a trig point onto the geometric methods of surveying through history all the way up to GPS.

Carter is something of an expert on Darwin, and inevitably the great man comes into the story many times - yet his appearance never seems forced. It's hard to spend your time in a natural environment like this and not have Darwin repeatedly brought to mind.

I confess to a distinct love of these moors. Having spent my first 11 years in and around Littleborough, just the other side of Blackstone Edge from Carter's moor, the moorland…

Ten Great Ideas About Chance - Persi Diaconis and Brian Skyrms ***

There are few topics that fascinate me as much as chance and probability. It's partly the wonder that mathematics can be applied to something so intangible and also because so often the outcomes of probability are counter-intuitive and we can enjoy the 'Huh?' impact of something that works yet feels so far from common sense.

I think I ought to start by saying what this is isn't. It's definitely not an introductory book - the authors assume that the reader 'has taken a first undergraduate course in probability or statistics'. And though there's an appendix that claims to be a probability tutorial for those who haven't got this background, it's not particularly reader-friendly - in theory I knew everything in the appendix, but I still found parts of it near-impossible to read.

As for the main text, if you pass that first criterion, my suspicion is that, like me, you will find parts utterly fascinating and other parts pretty much incomprehensible. Th…