There is a loose hierarchy of the cosmos that repeats. Stars form clusters, and then galaxies. Galaxies form clusters, and then these form clusters of their own, called superclusters. Gravity dominates the structure of such collections, yet all we feel and see from Earth is a relatively homogeneous distribution of stars. How do we see this hierarchy? If we zoom in, looking at a patch of sky so tiny that we can’t see any stars, what do we see? This patch of sky is about the size of a grain of sand held at arm’s length, and if we point the...
Image submitted to an image processing competition called ‘Hubble’s Hidden Treasures’ are expected to be amazing, but this is the only one I’ve seen that will make you happier. This cosmic ‘smile’ is in the constellation Ursa Major, and is made up of the light from four galaxies, each with Billions of their own stars. This is the biggest happy face ever found! The two eyes are very distant galaxies known as SDSSCGB 8842.3 and SDSSCGB 8842.4. So why do we see this ring structure? You might think that the Galaxy is stretched by gravity, but its something much more...
You might think simulating the entire Universe is difficult, and it is, but not for the reasons you would think. The Physics is actually somewhat straightforward. We know the math behind star formation, Gravity, and fluid dynamics, and throwing in a few other effects is not too bad. The hard part is finding a computer powerful enough to do the calculations in a reasonable amount of time. Think about it. Imagine having a universe of 100 Billion ‘particles’ used for a simulation. Each particle has a starting point, and that it pretty easy to do. But then for every...
You need to see this animation. It’s an amazing picture showing the Hubble Ultra Deep Field and the small patch of sky Astronomers had to aim at in order to photograph it. The moon is there for comparison. The patch of sky is about the size of a grain of sand held at arm’s length. Courtesy of gfycat.com, it really puts things in perspective. The crazy part is that if you look in any direction in the universe, in patches of sky as small as this one, you see the exact same thing. There are more galaxies in the Universe than we...