Friday, 14 February 2014

Cosmic radiation from the big bang discovered

It was in 1964 and two Americans, Arno Penzias and Robert Wilson owned a communication antenna that they were trying to make use of. But they were troubled by a persistent background noise, a steady steamy hiss that made experimental work impossible. The noise came from every point in the sky, day and night, every season.

The astronomers did everything they could to track down and eliminate the noise. They tested every electrical system. They rebuilt instruments, checked circuits, wiggled wires, dusted plugs. They climbed into the dish and placed duct tape over every seam and rivet. Then they climbed back into the dish with brooms and brushes and swept away all the bird droppings. But still the annoying noise was there.

Unknown to them, about 50 kilometres away researchers at a university were working on a idea that suggested years before by astrophysicist George Gamow: that if you looked deep enough in space, you should find some cosmic background radiation left over from the big bang. Gamow believed that by the time it had crossed the vastness of the universe the radiation would reach the earth in the form of microwaves. He had even suggested that the antenna that Wilson and Penzias were using would do the job of picking it up. So the noise that the antenna had picked up was what Gamow had anticipated. They had found the edge of the universe, or at least the visible part of it, 150 billion trillion kilometres away!!! They were seeing the first photons-the most ancient light in the universe- as microwaves.

   



The discovery of brown dwarfs

Not all stars are as big as normal stars, they just don't posses enough mass or a high enough temperature, not enough pressure in there core to start of major nuclear fusion reactions, stuff like that. These bodies continue to exist in space, but they are very hard to see because there temperatures and their brightness is much less than the stars that burn brightly- they are known as brown dwarf stars.

The first brown dwarf to be discovered was Gliese 229b in 1994. It is thought to be about 20 and 50 times the size of the planet Jupiter.


In 2011, what might be the coolest brown dwarf observed, its about 75 light years away from earth. Its called CFBDSIR 1458+10b and it has a temperature of around 90 degrees- about the same heat as fresh cup of tea!!!