How Do We Know The Universe Is ACCELERATING?
Support MinutePhysics on Patreon: http://www.patreon.com/minutephysics Aatish Bhatia helped write this video! A big thanks for his help! Here's his blog: http://www.empiricalzeal.com The...
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The universe is expanding.If you zoom out far enough, you’ll find that everywhere in the universe is movingaway from everywhere else.But once you know the universe is expanding, you might wonder if it’s going to keep expandingsomehow, or eventually stop and crunch in on itself because of the attractive forceof gravity.Well, all you have to do is point your telescope at a distant galaxy, measure how fast it’smoving away from us, wait about a million years, and then do the same thing again tosee if the galaxy is moving faster or slower than before.But if you don’t have a million years to spare, here’s what you do.You look at different galaxies.Because light takes time to reach us, when we look at a galaxy far, far away, we seeit as it was a long time ago.So looking...
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The universe is expanding.If you zoom out far enough, you’ll find that everywhere in the universe is movingaway from everywhere else.But once you know the universe is expanding, you might wonder if it’s going to keep expandingsomehow, or eventually stop and crunch in on itself because of the attractive forceof gravity.Well, all you have to do is point your telescope at a distant galaxy, measure how fast it’smoving away from us, wait about a million years, and then do the same thing again tosee if the galaxy is moving faster or slower than before.But if you don’t have a million years to spare, here’s what you do.You look at different galaxies.Because light takes time to reach us, when we look at a galaxy far, far away, we seeit as it was a long time ago.So looking...
