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[alway]

Something about it still doesn't make sense to me. If the universe is only about 14 billion years old and it is 30 billion light years away, wouldn't the distance between us and it have to be increasing faster than the speed of light?

I'm somewhat exhausted from work, so maybe I'm just missing something here...

That's actually what's happening. The universe is growing faster than light. Look it up.

And beyond that, it's currently accelerating due to dark energy. Dark because we don't know wtf it is, but it's uniformly causing expansion of the universe faster than it can collapse in on itself from gravity. Which means some sort of uniformly distributed negative energy. The discovery of its nature is one of the biggest mysteries in current physics, and will probably revolutionize it and our technology in pretty massive ways.

But anyway, yes. This is also why, given sufficient time, the farthest stars and galaxies in the sky will redshift to nothing. The Cosmic Microwave Background radiation, which you see in the sky in the microwave range, around what an analog TV receives, originally consisted of high energy gamma rays created as the universe cooled. And as the universe continues expanding, it's expected it will redshift to nothing in about 1 trillion years.

So when it is said 'the universe is 56 billion light years across,' it's really just shorthand for 'the visible universe is 56 billion light years across.' And yet, this is 'the universe' as far as we are concerned. Without travelling faster than light (which, thanks to Einstein means travelling backwards in time), you cannot run fast enough to get past that 'edge' of the universe. Anything slower than the speed of light, and the edge will recede due to the passage of time; at the speed of light, and the edge will stay at the same place. So in short, yes, there is probably more 'stuff' out there; but we can never interact with it through any force, light, spacecraft, or otherwise. And as such, it is outside of our universe.

It doesn't make any sense from a classical perspective; which is why, to understand it, you need to visualize space-time as a singular entity.

[Sirus]

Okay, thanks for writing all that stuff out and all...but I knew about dark energy, accelerating expansion, and the "visible universe" concepts for some time now. I just hadn't realized that the expansion had already exceeded the speed of light, hence my confusion

Legit happies: I keep getting free stuff. Yesterday it was an entire container of red licorice from a warehouse that I picked up a load from. Today it's an entire loaf of banana walnut bread from this coffee shop as they prepare to close. This is awesome.

[Thecard]

I keep getting free stuff. Yesterday it was an entire container of red licorice from a warehouse that I picked up a load from. Today it's an entire loaf of banana walnut bread from this coffee shop as they prepare to close. This is awesome.

Why would a coffee shop order hookers?

[Sirus]

I keep getting free stuff. Yesterday it was an entire container of red licorice from a warehouse that I picked up a load from. Today it's an entire loaf of banana walnut bread from this coffee shop as they prepare to close. This is awesome.

Why would a coffee shop order hookers?

They didn't. I'm here to take advantage of free Internet during my rest break, not deliver anything - hookers or otherwise

[Xantalos]

I nearly passed out several times tonight, and barfed twice.
Karate is FUCKUNG amazon.
Sorry for misspelling, little tired and shaky at the moment.

[alway]

Reading through the early XKCDs again.

[Putnam]

Something about it still doesn't make sense to me. If the universe is only about 14 billion years old and it is 30 billion light years away, wouldn't the distance between us and it have to be increasing faster than the speed of light?

I'm somewhat exhausted from work, so maybe I'm just missing something here...

Yes. Space can expand faster than the speed of light.

It's interesting, isn't it?

[LordSlowpoke]

Something about it still doesn't make sense to me. If the universe is only about 14 billion years old and it is 30 billion light years away, wouldn't the distance between us and it have to be increasing faster than the speed of light?

I'm somewhat exhausted from work, so maybe I'm just missing something here...

Yes. Space can expand faster than the speed of light.

It's interesting, isn't it?

therefore, space the matter in space are separate and i assume the speed of space would be a new universal boundary we should be working on in our somewhat smutty scifi fanfics

[Putnam]

Space has no speed.

[lue]

I once heard an idea that light used to move slower in the early days, which would imply it can/will be faster in the future, which would imply that perhaps current c does not take infinite energy to get to (speed-wise, that is.) Or rather, that somehow how fast you go with ∞ energy is inextricably linked to light's speed (or rather, how fast something like light can move through the Higgs field). And... and...and...

Note: I am not a physicist. Thus I estimate about 76.4% of the above paragraph is inaccurate.

Note: I am not an estimateur. Thus I estimate that about -6.79% of the guessed percentages in this and previous paragraphs are inaccurate.

Also: how about a game where you're a photon and you have to dodge Higgs Bosons on your way to wherever. Game starts at about 1 planck second per second, and at the hardest mode travels to 1s/s.
The Game Over message would be "Goddamn Particles got me again!"

[Putnam]

Yeah, that's very much under debate.

You've got your logic backwards. Light travels at the maximum speed because it has no rest mass; the speed of light has nothing to do directly with light. It's not inextricably linked to light's speed, it is literally the maximum speed of the universe, one which light happens to go at (because, again, no invariant mass). Also has nothing to do with the Higgs field; the Higgs field is what gives particles invariant mass, so light does nothing with that at all.

Also, it's called a Planck time, not a Planck second

[lue]

Yeah, that's very much under debate.

You've got your logic backwards. Light travels at the maximum speed because it has no rest mass; the speed of light has nothing to do directly with light. It's not inextricably linked to light's speed, it is literally the maximum speed of the universe, one which light happens to go at (because, again, no invariant mass). Also has nothing to do with the Higgs field; the Higgs field is what gives particles invariant mass, so light does nothing with that at all.

Also, it's called a Planck time, not a Planck second

Waitaminute, if it's actually called Planck time, then does that mean 1/60 of a minute called a second? Man, no wonder people give me weird looks when I say "I was able to complete that test in 2 minutes and 52 times."

But yeah, I realized how my "inextricably linked" statement was wrong right around the "(or rather," part.

And if photons don't interact with Higgs' stuff, then fine. I could make photons dodge phlogiston, or perhaps various unsavory particles in the luminiferous æther. I mean, one of those things must be something photons have to dodge in real life. Right?

[Sirus]

Make the game about a neutrino dodging other particles. Start with easy stuff like the interstellar void, end with entire planets covered in heavy water.

[Putnam]

Oh come on, that wouldn't even be remotely difficult until the very end. Friggin photons interact more than neutrinos.

[lue]

Obviously, difficulty rating would be what kind of particle you select.

Neutrino's the easiest
...
... (more options, don't know which ones nor how to rank them)
...
Antimatter particle of some variety is the hardest