Not yet a member? No problem!
Sign-up just takes a second.
Forgot your password?
Recover it now.
Already signed up?
Log in now.
Forgot your password?
Recover it now.
Not yet a member? No problem!
Sign-up just takes a second.
Remember your password?
Log in now.
12 Comments
enochsays...upvote if just for the pure awesomeness!
thanks KP!
Draxsays...Upvote for usage of lolcat font.
vairetubesays...dont forget local phenomenon
brainsays...When it says that the "known universe" is 93 billion light years across, they're referring to the "observable universe". This is the part of the universe from which light has had time to reach us. Interestingly, it's possible the universe is much much larger than that. It's also possible that the universe is smaller!
http://en.wikipedia.org/wiki/Observable_universe
I have a hard time understanding how the universe has no center. Everything I can find says it has no center and explains how the expansion has no center. I understand how the expansion has no center, but I don't understand how we can say for sure that the universe itself has no center. Can anyone explain that?
antsays...What song is this?
brainsays...Ant, apparently the song is Royksopp - Royksopp forever
vairetubesays...you know, the same people from the Geico commercial in the airport..
"everywhere i go.. there's always something to remind me... of another place and time... where love that traveled far had found me"...
dannym3141says...>> ^brain:
When it says that the "known universe" is 93 billion light years across, they're referring to the "observable universe". This is the part of the universe from which light has had time to reach us. Interestingly, it's possible the universe is much much larger than that. It's also possible that the universe is smaller!
http://en.wikipedia.org/wiki/Observable_universe
I have a hard time understanding how the universe has no center. Everything I can find says it has no center and explains how the expansion has no center. I understand how the expansion has no center, but I don't understand how we can say for sure that the universe itself has no center. Can anyone explain that?
I am not a qualified physicist, just a very interested amateur and i stand to be rediculed.
This is a piece of information i recall from "a brief history of time" and it was a while since i read it. And also, i must express that the maths involved is incredibly complex for any laymen including myself to fully 'understand' quite exactly what it means, and why it is realistic to use these analogies to give anyone who doesn't understand the maths (which is the only real way of PROVING this idea).
It's to do with how you consider the universe and therefore the expansion of it. The most famous example is drawing dots on a balloon and blowing air into the balloon - the dots get further away from each other and there is no centre. The difficulty is imagining that the baloon's surface is 2d and we're talking about 3d
You can then take 4d if you incorporate time, which would be the balloon inflating, so then you're talking about the 3d dimensions of the balloon as 4d. With the time dimension being shown by the radius of the balloon.
It's a trait of humans that we're limited in our view of things. Obviously, we imagine everything exactly how our eyes percieve it. We can see 3 dimensions, so that is our universe. Maths has given us understanding of a lot more dimensions and we can experiment and 'view' them in a mathematical way, but never beyond that. Like, we can't draw a tesseract (which is a 4d object), but we can draw the shadow of a tesseract.
That's because like out in the sun, our 3d objects throw a shadow and that shadow is 2d, so the 4d object's shadow becomes 3d.
I'm getting dragged further away from my point. I'll wrap it up with Hawking's explanation of time being like the surface of a planet. With the start of time being at the north pole and the end of time being at the south. If we imagine it in this way, we can see that there doesn't necessarily have to be something BEFORE time began (the big bang). Nor even something after time ends (big crunch?). Like Hawking has said before - there's no point asking what came before the big bang, it's a nonsensical question, "It's like asking what is north of the north pole?"
Also, these concepts have been shown to be true. All galaxies in space are moving away from each other.
rottenseedsays...^The answers to both "What happened before the big bang?" and "What's north of the north pole?" are the number '11' and the color 'periwinkle' respectively
oinkinsteinsays...amazing music, amazing facts, amazing universe. this is def favorited thanks for the post!
moodoniasays...*promote the wonder of the universe!
siftbotsays...Promoting this video back to the front page; last published Friday, July 3rd, 2009 12:15am PDT - promote requested by moodonia.
Discuss...
Enable JavaScript to submit a comment.