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SINCE THE EXISTENCE OF DARK MATTER was first suspected back in the 1930s, scientists have been trying to figure out what it might be made off. In the last eighty years all sorts of oddities with funky names have been put forward as candidates. We’ve had the mighty ‘Macho’ (Massive astrophysical compact halo object); the feeble ‘Wimp’ (Weakly Interacting Massive Particle); the villainous (in a sci-fi kind of way) ‘Axion’; the unfortunate ‘sterile-neutrino’; and the sexy ‘Susy’ (supersymmetry) particle.

Now there’s a new dark matter kid on the block and this one comes complete with magnetic doughnuts.

Dark matter makes up more than 80 per cent of all the matter in the Universe and accounts for more 26 per cent of the total energy (‘ordinary’ matter makes up less than five per cent of the energy). This mysterious substance doesn’t interact with the electromagnetic radiation   (heat, light, radio etc) that we rely up to see the Universe so it is invisible and is only detectable by the gravitational influence it has on stuff we can see.

It has been assumed that dark matter was invisible because it interacts through exotic forces that we are unaware of in our normal existence, but now there’s a new theory that puts dark matter back into the realm of the everyday.

MORE THAN 400 MILLION years ago, the Earth was a very different place than it is today. The climate, encouraged by excessive levels of greenhouse gases, was hot enough to ensure no water was locked away at the poles. Sea levels were a hundred metres higher than today and, in their balmy waters, sea life had exploded – dominating life on Earth. 

Then this all changed. Inexplicably, the climate cooled, glaciers formed at the poles, sea levels plummeted and more than 85 per cent of the Earth’s species died out. The Late Ordovician mass extinction, as it has come to be known, was one of the most catastrophic extinction events in the planet’s history, but what caused the climate to take such a dramatic U-turn?

One explanation is that the Earth was the unwilling recipient of a massive dose of gamma radiation gifted to us by a distant star, dying a violent death. Gamma ray bursts (GRBs) are the most powerful cosmic explosions we know of. When a massive star explodes in a supernova explosion, sometimes, as if in a fit of raw fury, the star will spew intense beams of deadly gamma radiation into the cosmos.

If the Earth was at the receiving end of such an outburst all those millennia ago, gamma radiation would have smashed into the atmosphere – destroying the protective ozone layer and blanketing the planet in suffocating blanket of smog that blocked sunlight and sent the climate into the tailspin that resulted in the death of more than three-quarters of life on Earth.

Well, get your best apocalypse trousers on, if some scientists are to be believed, the Earth could be on the receiving end of another dose of gamma rays.

This week marks the 70th anniversary of the iconic ‘Dam Busters’ raid on German dams. The strategic impact of the raids is still a matter of debate, but that doesn’t detract from the technical innovation of Barnes Wallis’ ‘bouncing bombs’ and the bravery of RAF 617 Squadron

ON THE EVENING OF MAY 16, 1943, 19 modified Lancaster bombers set out from RAF Scampton to attack the dams of the industrial Ruhr region in Germany.

The planes of the newly-formed 617 squadron were carrying a very special ‘bouncing bomb’ that, although it would have very little impact on the outcome of the war, would ensure the aircrew that deployed it and the man who designed it would be forever remembered as the Dambusters.

At the height of World War II, Bomber Command was tasked with destroying as much of Germany’s industry as possible.

They had tried targeting factories but these were quickly rebuilt so they turned their attention to targeting the power sources that supplied them – coal mines, oil fields and hydroelectric dams.

Coal mines were too easily repaired and the oil fields were too far away, so the dams, which supplied both power and water to industry, became the target. Unfortunately, aircrews faced two problems: first, dams are (damn) difficult to destroy – after all they are strong enough to hold millions of tonnes of water at bay. Only a very large bomb, or an underwater torpedo strike would do the job.

Second, Hitler was aware of the importance of his dams, so they were well defended by submerged anti-torpedo defences.

The large bomb idea was abandoned because the RAF lacked an aircraft big enough to carry it, so it had to be the underwater option. But how would the crews get past the defences?