Dr Seuss Every Day Should Be Banned Books Day Shirt

Dr Seuss Every Day Should Be Banned Books Day Shirt

Ever watch a whirlpool? How about water going down a drain or even a Dr Seuss Every Day Should Be Banned Books Day Shirt of cream swirled into your coffee? It sometimes looks like a spiral galaxy. And we once thought gravity was holding a galaxy together. If you watch a whirlpool carefully you will notice the outside orbits the center slowly and the closer to the middle you are the faster it spins. But this was a bit of a problem for galaxies because this would make the arms of the galaxy wind up tight. They would not last for millions of years. Earlier in the century, before computers, astronomer would hire dozens of women who were good at math to do calculations for them. One of them made an important discovery: the speed of the stars in the outer arms was way faster than it should be. The galaxy was spinning like a solid LP record album! According to the laws of gravity, which we know quite well, it shouldn’t behave like this…unless there was WAY more mass than we could see. And the issue of *dark matter* was born. Yes, there would be a lot of dust and gas and planets and small stars we couldn’t see. But all that is still not enough for the behavior we observe. It is a mystery we are still working on!

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Dr Seuss Every Day Should Be Banned Books Day Shirt, Hoodie, Sweater, Vneck, Unisex and T-shirt

Best Dr Seuss Every Day Should Be Banned Books Day Shirt

This is completely correct. The Big Bang model suggests that all structures in the Dr Seuss Every Day Should Be Banned Books Day Shirt, from super clusters down to dwarf galaxies are built bottom up, by the contestant merging of smaller clumps of stars, gas and dark matter. The statistics and nature of this merging process is at the heart of modern cosmology and can be used to discriminate against different types of dark matter and different idea about how galaxies form. The currently favored idea is that the smallest clump that can be made by direct collapse after the Big Bang is about the size of an earth – galaxies are built as clumps of this size merge to make bigger and bigger clumps. Some of these mergers are quite violent and stars can be flung to great distances like when an astroid strikes a planet- blobs of debris can be shot into outer space. Rogue stars are the galactic debris that’s wandering though space trying to get back to the galaxy that expelled it, but can’t (necessarily). The nature if the rogue star population depends on the merger history of the Milky Way. We don’t know this exactly but we can make some inferences. The Milky Way galaxy shows no real signature of a merger (like a bulge of stars). In fact it’s relatively thin disc can rule out a recent big merger. Thus the rogue stars that populate our “halo” would have to be old, dim red stars having formed along time ago. This is consistent with a lack of any strong UV emission (which comes from young hot stars) in the halo (although the brightness (or density) of these rogue stars is just barely detectable.)

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