Thursday, October 13, 2011
THE UNIVERSE IS...ARE YOU READY FOR THIS...FLAT!!!!
That's what physicists are telling us now...that the universe is flat. Twenty years ago it was considered curved; saddle-shaped, in fact. Man, things are changing fast! It's an exciting time to be a cosmologist, but a confusing time for everybody else.
So where did this idea come from? The answer is contained in the 15 minute video above. Tor Barstad says we have a reliable way to measure the curvature of light from two celestial objects billions of light years away, and that these lines and angles show no bending, as they would if the universe was curved.
Here's (above) a simpler explanation. This six minute video takes a while to get started, so I recommend beginning at the two minute mark.
It's hard to know where all this is going, and new discoveries could change the picture in unpredictable ways. A couple of weeks ago it was discovered that a neutrino might be able to travel faster than light. If that turns out to be true, that could have a big effect on cosmological calculations, even though the faster speed increment is very slight.
BTW, there's a couple of interesting comments under this YouTube video. One says that "flat" refers only to the relatively even distribution of energy in the universe, but Tor Barstad's video definitely talks about flat in terms of geometry.
This one minute video (above) isn't relevant, but I'll put it up anyway because it's so interesting. It turns out that there's one thing we know for sure that can travel faster than light, and that's space. After The Big Bang space itself expanded faster than the speed of light, and is still expanding that fast. Anything traveling within existing space is limited to the speed of light.
It's strange to think how space is now regarded as a thing with definite properties, and with measurable energy.
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10 comments:
Fascinating! I always thought maybe the universe is a finite space but if we kept flying forward in space eventually we'd end up in the same place, similar to how if you walk straight around the globe eventually you'll return to the same point.
In regards to the bottom video, if space is expanding faster than anything within space can travel, that means we'll never be able to catch up?
Also the theory is that the neutrino isn't going faster than the speed of light at all but it's traveling backwards in time
Joshua: Neutrinos travel back in time? Holy Mackerel! I never heard that before. Can you remember where you read that?
I think it's cause neutrinos have (pending extensive peer review and recreation of experiments) been shown to move slightly faster than the speed of light, which would (for reasons I don't know since im not up on my relativity) make them travel back in time or some weird quantum thing. Einstein does say that there is nothing barring something that is already travelling faster than light from doing so, just that you can't accelerate past the speed of light cause of the whole "mass gradually approaches infinite faster you go" thing. Conceivably if neutrinos are already travelling at the speed of light instantaneously from their instant of creation they would not be breaking any laws.
Have you heard of the theory that our universe is just a holographic projection? Wild stuff, my problem with stuff like hyperdimensions and superstrings is it's getting progressively harder for people without advanced degrees to graps, even with clever analogies.
This is an interesting parallel to the discovery that the earth was round. Amazing how in this universe of spheres the very universe itself could be flat.
I actually read it in a newspaper but here's an article online
http://bit.ly/qMhlBn
The wikipedia article about the neutrino says "As noted by Gregory Benford, among others, special relativity implies that tachyons, if they existed, could be used to communicate backwards in time."
And I also heard this clever joke on the subject: http://bit.ly/oFoT1t
Are you familiar with Ted Greene Eddie? He was a famous jazz guitarist and teacher that lived in Encino till his untimely death in 2005. http://www.youtube.com/watch?v=Zkuo2384ZN4 I've been watching videos of his lessons and lectures on jazz, classical and rock music, they're full of interesting digressions and philosophical ideas. He reminds me of you more than anyone else I've ever encountered, it's actually kind of eerie, he's pretty much you if you dedicated your life to music instead of art. I know you're into music and "theory" in general though so I thought you'd find him interesting.
http://www.youtube.com/watch?v=4DJdJi9wjKo check out this version of Eleanor Rigby!
Joshua: Aaaargh! When a joke's really clever I almost never get it. I asked my daughter to explain this one and she said it reminded her of the minimalist blond jokes that used to go around, jokes like: "The Blond walked into the bar." That's it...that's the whole joke. I didn't get that joke either, until she explained it to me.
Anon: Wow and Double Wow! Those were great videos, especially the first one.! I hate to admit it, but I never heard of Ted Greene until you mentioned him. I definitely will go back and check out some of the other videos. Many thanks!
Mush replied to a much earlier post:
"Wonderful strips, Eddie! Hey, if you din't know, there're more Kurtzman strips over here, including the one you showed! http://comicrazys.com/2008/06/12/silver-linings-harvey-kurtzman/"
Mush: Very nice! You say there's more Kurtzman there? Thanks, I'll check it out!
Anon: The holographic projection theory is fascinating, but very hard to believe. Boy, no wonder science fiction doesn't sell as much as it used to...the stuff coming out of universities is much more over the top.
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