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Global Dimming and Death of Our Sun

Posted by jase on July 10, 2009

by Brian Cox

The Sun is Dying

Sol, our 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.

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Posted in Astronomy, Climate, Earth, extinction, Global Warming, Science, Solar Energy, Space | Tagged: , , , , , , , , , , , | Leave a Comment »

Was the Universe Destroyed by Dark Matter?

Posted by jase on July 7, 2009

Did dark matter destroy the universe?  You might be looking around at the way things “exist” and thinking “No”, but we’re talking about ancient history.  Three hundred million years after the start of the universe, things had finally cooled down enough to form hydrogen atoms out of all the protons and electrons that were zipping around – only to have them all ripped up again around the one billion year mark.  Why?

Most believe that the first quasars, active galaxies whose central black holes are the cosmic-ray equivalent of a firehose, provided the breakup energy, but some Fermilab scientists have another idea.  Dan Hooper and Alexander Belikov posit that invisible, self-destructing dark matter may have blown up every atom in the universe.  At least it’s plausible in that if we wanted to ionize an entire universe, we’d want something that sounded that awesome.

Dark matter is a candidate for providing ionizing radiation because, if it exists at all, it’s its own antiparticle: if two dark matter particles hit each other they can blow up.  Insane as it sounds, the theory predicts that despite making up most of everything the particles themselves are so tiny, and so terribly fussy about colliding, that they can form huge structures without destroying themselves.  Positron emissions which may be an indication of exactly this kind of self-destruction have been observed by the European PAMELA satellite currently orbiting the Earth.

As theories go, this one is more awesome than accepted.  The quasar hypothesis has wide support, and crediting something we’ve never even seen with reshaping the universe may be going a little far.  Then again, that’s what modern cosmology is doing with dark matter anyway, so maybe this idea will fit right in.

Posted in Astronomy, Earth, extinction, Extraterrestrial Life, Science, Space | Tagged: , , , , | Leave a Comment »

350 Year Old Photo Uncovered of Dodo Before It was Extinct

Posted by jase on July 7, 2009

A previously undiscovered 17th century picture of a dodo, drawn before the bird became extinct, is to be sold at auction by Christie’s.

The drawing, which dates from the late 1600s, offers a rare insight into the appearance of the flightless bird that was the first recorded casualty of human interference in the habitat of other creatures.

Dodos were the main predators on Mauritius until settlers introduced bigger animals to Indian Ocean island, including pigs. Many were shipped to Europe as curiosities or had their nesting areas destroyed and the species was extinct by 1700.

The 350-year-old drawing, described by Christie’s as “vibrant”, is one of a small number of images of the unfortunate bird whose demise was largely unnoticed until a dodo featured in Lewis Carroll’s popular 1865 book Alice’s Adventures in Wonderland.

Painted by an unknown artist of the 17th century Dutch school in about 1650, the unframed 10×8 inch picture is expected to fetch up to £6,000 when it is sold by Christie’s in London on July 9.

The auction house believes it differs from existing images, many of which were drawn from a small number of dodos that were put on display in Europe, some of which were later stuffed.

Little is known about the origin of the picture, which has never before been published.

The inscription above the bird, ‘Dronte’, was the Dutch 17th-century name for the dodo, although at this period it was also used in a number of other languages including French, German and Italian.

Julian Hume, a dodo expert and a palaeontologist at the Natural History Museum, said the image was “very interesting but rather odd”.

“The lack of tail is anatomically correct – the ostrich-like plumes normally depicted are exaggerations – but this may be a fault by the artist,” he said. “The angle of the dodo is also novel, showing a 3D pose rather than the usual side view.”

He added that it was likely to have been copied from earlier drawings. “The image is somewhat based on Roelandt Savery’s 1626 image of the dodo standing by a rock. We know so little about the number of transported live dodo specimens, and coupled with repeated plagiarism of images, factual determination is almost impossible to obtain.”

Another dodo expert, Anthony Cheke, said: “There is always a lot of interest in artefacts like these because the dodo is such a curiosity. This is certainly an unusual image although the drawing is, frankly, not very good even by contemporary standards.”

Posted in Animals, extinction | Tagged: , , , , , , , | 1 Comment »