General Discussions > Education
No science child board?
cisdad:
--- Quote from: Tracey on December 15, 2011, 06:45:28 pm ---I just feel that going by the Big Bang theory, there is a finite amount of material expanding. The leading edge of that expansion is somewhere right now, what's it running into? I have the dark matter riddle solved, I'll reveal it in a later post. Hugs, Tracey
--- End quote ---
Dark matter is obviously the socks our dryers eat.
For the universe, you've got a common wrong image in mind. You're thinking of, say, we're in a large room observing things. Inside that room, we set off a firecracker (the big bang) and we watch the material expand in to that room. The crucial thing wrong here, even if hard to explain, is that you assumed there was space, and that space is separate from the universe. Once you get in to General Relativity, space is very much an active player in the universe -- and is inseparable from it. The universe is the matter/energy/_and_ space.
For the peculiar business of there being no 'outside' to look from, conduct this experiment. Take a strip of paper and a piece of tape. Before closing the strip, flip over the end. Then tape it closed. Now take a pencil and start tracing down the length of the paper. Keep going until you get back to where you started. You started on the inside, so everything you could reach is also inside. But you've covered 'both' sides of the paper. While the details are different for the universe, this seems to be how it is constructed -- there's no 'outside'.
Unrelated thing to do with that strip (a Moebius loop) is to take a pair of scissors and cut it lengthwise down the line you just drew. I won't spoil the story for you.
A good book to read on the Big Bang is Stephen Weinberg's _The first three minutes_. It doesn't have much on the general relativity side of things, but gives a good description of how we know that there was a Big Bang. If your math is comfortable with tensors, then B. F. Schutz's Introduction to General Relativity is a good one to get started on the weirdness of space being an active player in the universe.
Jennifer:
Great thread Pinkfluff,
Speaking of the nature of the universe, did you hear that scientists at CERN believe they have discovered evidence of the long sought after Top Quark, aka The Higgs Boson?
Jennifer
cisdad:
Higgs is a very different creature than the top quark. Not least, Higgs is not a quark, so it can exist freely in space, unlike the top, or any other quark.
It's big news if the find is confirmed. One report I've seen (about 12th hand) has it at 125 GeV, which is lighter than I thought the lower bound was previously established to be (something like 150-180).
Fingers crossed. Or not. It'd be much more interesting if the Higgs weren't found anywhere near where it was expected.
Jennifer:
--- Quote from: cisdad on December 16, 2011, 10:13:10 am ---Higgs is a very different creature than the top quark. Not least, Higgs is not a quark, so it can exist freely in space, unlike the top, or any other quark.
It's big news if the find is confirmed. One report I've seen (about 12th hand) has it at 125 GeV, which is lighter than I thought the lower bound was previously established to be (something like 150-180).
Fingers crossed. Or not. It'd be much more interesting if the Higgs weren't found anywhere near where it was expected.
--- End quote ---
Thank you for correcting me. :) The Top Quark was of course experimentally observed at Fermilab in 1995 and the Higgs Boson is the last fundamental particle predicted by The Standard Model that has yet to be observed. Do you think Sheldon and Leonard are excited? ;D
Jennifer
cisdad:
I'll guess that Leonard is a little down because it wasn't his experiment that caught it.
Sheldon is ho-humming it because it is merely an experimental result and doesn't say anything theoretically interesting. :). Different matter if it said something about quantum loop gravity that he could use against Leslie Winkle.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version