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Wondrous Wednesday 16: Losing the Universe

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Summary

Universe expansion: space between galaxy clusters expands (not within gravitationally bound areas). Light can't cross ever-growing distances. After 1M years: 0.02% galaxies lost. 10B years: 80% lost. 150B years: 99.999997% lost - only local group visible (50 galaxies, 2 trillion stars). Red dwarf stars last 10 trillion years. Dyson swarms could harvest star energy. Last stars: 10^19 years. Sun consumes Earth in 5B years anyway.

Transcript

0:00 Welcome to ANI in the air wondrous Wednesday where I talk about something
0:04 wondrous. So today I thought I would talk about this, it was a vlog posting I came
0:13 across and essentially it's about losing the universe. So the universe under our
0:28 current understanding of it is expanding and apparently, I didn't actually know
0:35 this, it's kind of embarrassing, but I guess it doesn't expand in the parts that are
0:40 gravitationally bound, so like inside of galaxies or clusters of galaxies, but it
0:46 the clusters, the space in between them expands and so as time goes on it gets
0:56 farther and farther apart and so as the light from those stars travel I can't
1:04 actually cross the distance of all that expansion at some point. And so the idea
1:15 is basically we're losing a view of the universe and and so kind of if you're
1:31 just at any point in the universe you think about how far it's been since the
1:38 Big Bang when it all started. I believe that's still fashionable to consider
1:43 that as part of the the model. Then you know how much can you not see from
1:50 that point. So there's a table on this thing, it says after 1 million years 0.02
1:56 percent of the galaxies are lost, 10 million years 0.2 percent, 100 million
2:00 years 2 percent, 1 billion years 20 percent, 10 billion years 80 percent, 150
2:09 billion years approximately 99.999997 percent of the universe is gone. So we're
2:23 you know we're at a point where we can still see a lot of the universe but in
2:37 about a hundred and fifty billion years that's about five billion in about five
2:43 billion years we the Sun explodes and consumes the earth so I don't really
2:49 need to worry about this but after about 150 billion years essentially what we
2:56 see will be our local cluster of galaxies and so there's about I guess
3:09 our local group has about 50 nearby galaxies and in total that comes to
3:15 about two trillion stars so still a lot but the rest of the universe will just
3:22 be blackness and incidentally in case you were curious and I certainly didn't
3:30 know this after 150 billion years
3:36 they'll still be the smallest stars powered by fusion the red dwarf stars
3:46 they're expected to last about 10 trillion years so one could potentially
3:52 still have life going on probably I don't know about forming new life or not
3:59 no idea but certainly if existing life such as ourselves manages to get off
4:06 this planet and start propagating across the galaxy and across the other ones you
4:14 know it on these timescales is quite possible and there are things called
4:19 like well Dyson sphere is the short name but Dyson swarm is kind of the cool
4:26 thing where it's like pieces of stuff circling the Sun and kind of collecting
4:34 the energy from the Sun and surviving off of that and so by changing where it
4:39 is based on the power of the Sun the star that you're happen to be around you
4:46 know you can you can make things work and then the post continues to finish
4:55 off with that that apparently the last of the stars current model will be 10
5:10 quatillion years that's a 10 or I guess a 1 followed by 19 zeros so that is what's
5:25 in that post I just thought that was kind of cool I know the idea of just the
5:31 universe going far away from us expanding expanding till we're just this
5:38 small little group of galaxies two trillion stars I think of that when the
5:47 next time you see Doctor Who and visiting some you know traveling through
5:52 all of space and time and like half the episodes on earth it's like really you
5:57 know I love the show just saying but um alrighty I'll hopefully post that link
6:06 along with this podcast alright well that is wondrous Wednesday I hope you
6:13 are wondering what the heck I was just talking about and maybe click on that
6:16 link you all have a good day I'll see you when I see you hopefully before the
6:24 universe fades away