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[Cryxis, Prince of Doom]

Not as heavy as some useless telescope
Pshhh

[Quartz_Mace]

If the universe is constantly expanding, what is it expanding into?

[Cryxis, Prince of Doom]

I just thought the edge of our observation was the point where the universes expansion is greater than the lights ability to reach earth or something like that

[i2amroy]

The way that I heard it explained is that as you get farther away the light has to have been traveling farther to have reached you. The "edge" of the universe that we can see is because that's the point where the light that we are seeing is the light from right after the big bang. We can't see any farther then that because the light from anything farther away hasn't had time to reach us yet.

(This also has the nifty side effect that no matter where you are standing it seems like you are standing in the exact center of the universe, since the "limit" is based off of the speed of light and your current position.)

[Cryxis, Prince of Doom]

So what would happen if something went faster than the speed of light?
I say something because it would have to be a very special 'thing' to pull that off

[i2amroy]

So what would happen if something went faster than the speed of light?
I say something because it would have to be a very special 'thing' to pull that off

As far as we know you can't (or at least not locally).

If you worked around it some way (such as through wormhole) it would look like the universe was two unconnected bubbles, one large one centered on you and one smaller one on the other end of the wormhole.

As for what would happen to you if you actually did go faster then light, you actually end up arriving at your destination before you leave (as a weird version of time travel), which is one of the reasons we don't think it could happen, since it plays hell with causality. It would also seem like the universe had "moved", in the sense that things on one side (the one you were traveling away from) would disappear and things on the side you were traveling towards would suddenly appear from nothingness.

[Quartz_Mace]

So what would happen if something went faster than the speed of light?
I say something because it would have to be a very special 'thing' to pull that off

As far as we know you can't (or at least not locally).

If you worked around it some way (such as through wormhole) it would look like the universe was two unconnected bubbles, one large one centered on you and one smaller one on the other end of the wormhole.

As for what would happen to you if you actually did go faster then light, you actually end up arriving at your destination before you leave (as a weird version of time travel), which is one of the reasons we don't think it could happen, since it plays hell with causality. It would also seem like the universe had "moved", in the sense that things on one side (the one you were traveling away from) would disappear and things on the side you were traveling towards would suddenly appear from nothingness.

So, you'd essentially break physics, DF style?

[Cryxis, Prince of Doom]

Ya I'd heard that before but I meant just a particle

Worm holes don't realy found because you're taking a short cut and not actualy reaching the speed.

What if faster than light things exist but we just can't observe them?

[Quartz_Mace]

Ya I'd heard that before but I meant just a particle

Worm holes don't realy found because you're taking a short cut and not actualy reaching the speed.

What if faster than light things exist but we just can't observe them?

Then let's hope one doesn't hit the Earth.

[i2amroy]

What if faster than light things exist but we just can't observe them?

They've already been theorized in the form of Tachyons, but so far no experiments we've done to try to detect them have shown anything. That said the biggest reason why we don't think they exist is:

Most physicists think that faster-than-light particles cannot exist because they are not consistent with the known laws of physics. If such particles did exist, they could be used to build a tachyonic antitelephone and send signals faster than light, which (according to special relativity) would lead to violations of causality.

[Cryxis, Prince of Doom]

Ah
Well...

What would happen if a theoretical tachyon struck a black hole?

[i2amroy]

Ah
Well...

What would happen if a theoretical tachyon struck a black hole?

They've got imaginary mass, so AFAIK it would just shoot straight through it. Lots of things (like gravity, and crashing into things, etc.) wouldn't really apply to a theoretical tachyon AFAIK.

[TheDarkStar]

Any FTL phenomenon allows time travel (and other bizarre things), even wormholes. That's why we're pretty sure it's impossible.

[Cryxis, Prince of Doom]

So it would pass straight through the densest thing that exists in this universe?

[TheDarkStar]

Yes, because it doesn't interact at all. This brings up the point "Why does it matter if it exists or not if it has no effect on the world?"