© Pint of Science, 2018. All rights reserved.
This evening is all about the parts of the universe that we can't see, or is missing. We will hear about using X-rays to study black holes, the least understood objects in the universe. And we will hear of the search for antimatter, a 'mirror-image' of normal matter of which 99% has been lost since the Big Bang.
Why is that pint not made of antimatter? And: Why has the universe not annihilated itself?
Antimatter is like matter, except everything is opposite - electrons and anti-electrons for example have opposite charge. When matter and antimatter meet, they annihilate, producing a lot of energy. Conversely, matter and anti-matter can be made from energy. We got pretty good at that. We can even make anti-hydrogen, the most important ingredient in anti-beer. But why do we have to make it? Lots of it was created in the big bang. Where has it all gone? And why didn’t the matter disappear along with it? Why is there stuff in this universe - enough of it to make stars, planets, people, pints?
X-raying Black Holes
Black holes are so dense that not even light can escape. So how do we “see” them? As gas falls towards a black hole it gets hot, glowing X-rays. These flows are detected by space-based observatories. By analysing these X-rays we can study the environment. Astronomers can even measure the warping of space & time and infer that some black holes are spinning rapidly. It is surprising that super-massive black holes play a key role in the evolution of their host galaxy, and even that of clusters of galaxies. I will take us on a tour of X-ray observations of black holes from small to large scales.