Comments on: Dumb questions with smart answers #23: Why is space dark?

By: em

em — Sat, 07 Feb 2009 09:33:00 +0000

very interesting!

but this is what makes my brain almost short circuit-

so the universe is still expanding, so the space that the universe inhabits is even bigger…but what’s containing *that* space?

like- where is all of this stuff being held, and how could just infinite space exist?
makes me think of all the ancient myths about nothing but Chaos existing, and from Chaos came the gods.

By: Brad

Brad — Fri, 06 Feb 2009 15:39:00 +0000

Astrophysicist here:
your answer is basically correct except for one thing: the Universe is not necessarily finite in extent. There’s no way to know. We DO know that it’s bigger than the horizon (the total distance light could travel since the Big Bang). There’s just no way to prove that it’s infinite or finite if there’s no way to see outside this horizon. Thankfully, the solution to Olber’s paradox doesn’t depend on this point. The age of the Universe and redshift are good enough by themselves.

By: Joel

Joel — Fri, 06 Feb 2009 14:48:00 +0000

Thank you William in Boston– your remarks regarding the finality of the universe are quite on point. To expand on it:
The assumption by physicists that the universe is finite is more a relic of conservation of mass than anything else– if the “big bang” theory is correct, then scientists make the assumption that the original element of the big bang must have had a finite mass. However, things we “knew” to be true have not proven to be “universal” (pun INTENDED), especially regarding Newton’s laws, which have lost a lot of meaning in terms of “space” and the atomic level since Einstein’s theory of relativity.
Besides that, the possibility that space is not finite (i.e. infinite) has an infinite amount of possible (not necessarily plausible) explanations, but that’s another conversation.
This page reminds me of those binge-drunk conversations my fellow engineers and I used to have regarding space’s finality, like, “if the universe is infinite, then is there someone somewhere doing the exact same thing and talking about the exact same topic as us right now?”

By: Dummy

Dummy — Fri, 06 Feb 2009 13:26:00 +0000

is the universe is expanding, what is it expanding into? what is on the other side…

By: Vickey

Vickey — Fri, 06 Feb 2009 11:21:00 +0000

I just have trouble imagining space being infinite. It’s hard to wrap my head around the idea that space is not some actual finite space. I think of space like a huge room, and what’s outside surrounding the room? I’ve thought about that for years, and it still blows my little pea-brain away…

By: maumau

maumau — Tue, 09 Oct 2007 01:22:23 +0000

hey the universe isn’t dark….
there are things which is hidden from our eye sight as our retina can’t be focus all the things to our brain.
Besides is all under gravity control.
No gravity, no life exist!

By: WUGGY6X9

WUGGY6X9 — Mon, 08 Oct 2007 19:49:19 +0000

The amazining universe.I just can’t get enough of it!

By: t

Mon, 08 Oct 2007 17:03:44 +0000

if there are so many objects in space, it would stand to reason that millions of objects are behind other objects. so a star we see in the sky could have hundreds, thousands or millions of objects behind it “blocking” that light.

when the planet moves, stars become visible while others go away from sight. the ones that become visible then have other stars behind it that become non-visible. and this is only in a 2d plane since that is our way of “seeing” objects. we cant look around an object 50 million light years away until the planet moves to a different angle, which then blocks more. etc etc etc.

By: PM Toone

PM Toone — Wed, 12 Sep 2007 13:41:25 +0000

Dumb questions with smart answers #23: Why is space dark?

Dumb answer: Lack of light.

By: Sheralyn

Sheralyn — Tue, 11 Sep 2007 23:19:42 +0000

I’ve often wondered if the “Big Bang” was only one of a succession of Big Bangs…