You and your dog will separated and continue receding away from each other. That's essentially happening everywhere: space is expanding between everything, so we are drifting away from other galaxies. The Universe is infinite, and we can constantly drift apart from other objects because space is being created in between us.
Here's a GIF I made that might help you get it:. You can see how the galaxies drift apart as the space between them increases. And this happens everywhere in the Universe. The Universe is infinite, but more and more space is being created between matter. Fun fact: These objects can actually drift away from each other faster than the speed of light. That is, light from them eventually won't make it to us, since they'll be drifting away too quickly.
Now, this doesn't actually go against Einstein's theory that the speed of light is the fastest thing in the Universe. Einstein said that nothing can travel through space faster than light — but here, space itself is actually being created between the objects. Distances are increasing because space itself is dilating, and thus we can drift apart from other objects faster than light. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group.
Create a free Team What is Teams? The universe will still age tens of billions of years during your trip. The sun and the earth and everything you've ever cared about will have long since been destroyed. Not that it matters much. You won't be able to loop back to earth , anyway. It is most decidedly a one-way trip. Finally, it takes a little while to get up to speed. You may want to send robots who won't get bored or who don't feel any adverse effects from tremendous g-forces.
I won't begrudge you that, and for most of what follows, it doesn't matter anyway. Just to make things as "realistic" as possible, let's figure out how things would work in a spaceship that accelerates at one-g so it feels like earth-normal gravity in the ship, with the back as "down".
Around midway through, you'll start to decelerate at the same rate, at which point, you and all of your stuff will be tossed to the front of the ship as though you were in free-fall. So far, everything has sounded pretty dire, but traveling at near light-speeds has some advantages as well. One of the great predictions of special relativity is that the clocks of moving observers seem to run slow, and the closer you are to the speed of light, the slower that your clock seems to run.
A one-g acceleration is surprisingly swift. After only a year or so, you'd be traveling at close to the speed of light, so for the vast majority of the billions of years that it'd take to reach another galaxy, you'd be cruising along at nearly the speed of light, which means that your personal clock will start to run very, very slow.
By the time you reach a cruising speed the one with all of the 9's above , you'll age about 10 billion times slower than the stationary chumps in the rest of the universe. Every day distant galaxies get further and further away. And what with the universe accelerating , any given galaxy gets more and more distant the longer you wait.
I guess what I'm trying to say is that we should probably leave now, before things get worse. Surprisingly, there's another problem with an expanding universe: the expansion acts like a drag and slows your ship down. This is the same effect that causes light from the big bang to to get redder and redder lower and lower energy as time goes on.
And since light travels at the very fastest speed possible, this means that no type of information or signal has had time to reach the earth from these far away points. Such locations are currently fundamentally outside our sphere of observation, i. Every location in the universe has its own sphere of observation beyond which it cannot see. Since our observable universe is not infinite, it has an edge.
This is not to say that there is a wall of energy or a giant chasm at the edge of our observable universe. The edge simply marks the dividing line between locations that earthlings can currently see and locations that we currently cannot. And although our observable universe has an edge, the universe as a whole is infinite and has no edge.
As time marches on, more and more points in space have had time for their light to reach us. Therefore, our observable universe is constantly increasing in size. You may think therefore that after an eternity of time, the entire universe will be observable to humans. There is, however, a complication that prevents this. The universe itself is still expanding. Although the current expansion of the universe is not as rapid as during the Big Bang, it is just as real and important.
As a result of the expansion of the universe, all galaxy groups are getting continually farther away from each other. So what's next? She was a computer there. If you're interested in this at all, there's a really good book called The Glass Universe that talks about all of these computers who worked at the Harvard College Observatory, including Annie Jump Cannon, who's very famous for figuring out the brightness of stars, a relationship about that. Henrietta Swan Levitt determined this first standard candle.
So she was working at the Harvard College Observatory, examining photographic plates from telescopes. So these telescopes were taking all these images and they needed people to reduce the data, which is something that a lot of physical computers do now, but people did back then.
And she was looking at a particular type of star called a Cepheid variable, and she realized that there was some sort of a relationship between how fast they dimmed and brightened and what their brightness was. These Cepheid variables are very consistent, so she had this idea that, because luminosity and period are the same, maybe they could be used to figure out how far away something is. So the standard candle idea is that a candle has an intrinsic brightness that we know.
We can determine it because of some sort of physical relationship or just studying physics in general. This star, if we know this other thing about it, we know how bright it is if you were standing at a certain distance from it. OK, so if we know how bright it should be and we know how bright we're observing it, we can actually figure out the distance based on that, right? If you know how bright your flashlight is and you know how bright you're seeing it, you can figure out how far away it is.
ERIC: So the further away something is, the dimmer it appears to us, and if we know its true brightness, it's pretty easy math to calculate how far away it must be to appear how we see it. So they figured out that these Cepheid variables could be used in this way as a standard candle. Although, my personal favorite standard candle is a type 1A supernova.
And that's entirely because, when I was in college, I worked on a project on SS Cygni, which is a very well known cataclysmic variable.
And what a cataclysmic variable is is it's a red giant star, and it has a partner a star, a binary star companion, called a white dwarf, and actually, most stars in the galaxy are in multiple star systems, so it's pretty normal to find a binary star system. So in a cataclysmic variable, you have this red giant and you had this white dwarf, and the white dwarf is close enough to the red giant that it steals mass from the red giant.
It doesn't know what that mass belongs to and it takes it on and it turns into this disk that goes around the white dwarf and there is a point at which there's too much mass in the disk, it becomes unstable, it all falls on to the white dwarf and the white dwarf brightness suddenly.
And because we know what that mass is, there's a mathematical physical relationship between how much mass is in that disk. You then know how bright it is. You've got your E equals mc squared, so you know how much mass is going to turn into an energy, and then you can figure out how far away is.
ERIC: And this takes us even further out on the distance ladder, because these things are so bright, we can see them from really far away and we can measure larger distances. Yeah, and actually, that's how we got our first distance to the Andromeda galaxy was Edwin Hubble, who you may have heard of because of a certain telescope.
There was a person that that's named after. So Edwin Hubble in used Cepheid variables that, as Henrietta Swan Levitt had posited you could, to figure out how far away the Andromeda nebula was, because at that point they didn't know that galaxies were galaxies. But he used it to prove that it wasn't inside of the Milky Way, and his number was about , light years.
He used 12 Cepheids to figure that out. We now think it's about 2. ERIC: All right, we can use these methods to estimate distances to other galaxies that make up the universe, and now, we're at the end of our journey.
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