Categorizing objects in the universe can be difficult. The fiasco with Pluto over the last decade is more than proof of that. We generally look to location and then to size as the two main methods for classifying the stuff that permeates the cosmos. Galaxies contain stars, which host orbiting planets, which host orbiting moons; While asteroids fly in between planets and icy comets are wander through the outskirts of star systems. But what about the in-between objects? Often we find strange things in strange places. There are moons in our solar system that are larger than planets. What would...
If you could see through the lens of a very powerful telescope, to an area of sky the size of a grain of sand held at arm’s length, a new universe would be revealed to you. For in that tiny patch of seemingly empty sky, there are thousands of galaxies visible, albeit with many hours of light collection. Observing the most distant of these galaxies, at the edge of the universe, allows us to estimate the number of Galaxies present in the distant past, when the universe was very young. As our observations improve, and our ability to simulate the conditions of the...
When I do a planetarium show for an audience, and they see the night sky for the first time, I always ask them ‘What do you see?’ The response is the usual stuff – Stars, the Moon, maybe planets, or the Milky Way. But they seem to be missing the most important and largest part of the sky – the Darkness. Space itself. Stars light up the cosmos, but if there were no stars, would we think that the universe was empty? Perhaps, but if you can imagine this scenario, it gives you an important perspective when you want to...
After yesterday’s post about some data that has caused us to rethink a theory, I wanted to follow it up today with an even bigger bit of data that could substantially change an even bigger theory. Dark energy was discovered as a large-scale repulsive force in the universe that is responsible for the acceleration of its expansion. It was discovered by looking at type 1a supernovae in distant galaxies. since the supernovae all explode with the same mass limit, they appear to all have the same intrinsic luminosity. If we know how bright they actually are, we can compare them...
The deeper we peer through the cosmos, the more we are looking into the distant past. Light from other galaxies takes millions of years to reach us, and so when that light has finally arrived at Earth, it is millions of years old, a snapshot in time of the distant galaxy. The furthest we can see is so far back in the history of the universe, that galaxies haven’t even formed yet. As we look at the large-scale structure of the Universe, we see it filled with a cosmic web of galaxy clusters, containing tens of thousands of galaxies each....
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...
