[wallijonn]

Quote:

WASHINGTON (Reuters) - Einstein was right -- again. Satellites that have been pulled slightly off their orbits show that the Earth is indeed twisting the fabric of space-time as it rotates, scientists said on Thursday.

some more details can be found here:

http://www.reuters.com/newsArticle.j...toryID=6575621

 

[bangraman]

I saw this a couple of days ago. Interesting article, it proves Einstein's theories and makes space/time warping for travel a definite theoretical possibility. I do wonder however what happens to objects contained in the warped space/time area both during the warping process and after.

 

[shimage]

Quote:

Originally Posted by bangraman [It] makes space/time warping for travel a definite theoretical possibility.

No, it doesn't. I don't know GR, but I do know that Einstein would strongly disagree with this statement. There is no way to "cheat" the system, as far as he was concerned (and, as far as I can tell, every physicist agrees with him).

 

[JeffL]

That article said a very much bloated version of basically nothing at all. What else is in the news?

 

[Flasken]

wauw, cool!

 

[MD1032]

Very interesting. Good find.

 

[PinkFloyd]

Walli,

Your soo deep these days man..... you haven't been to a dentist who listens to the Carpenters have you?

Mike.

 

[jnewman]

Quote:

Originally Posted by shimage No, it doesn't. I don't know GR, but I do know that Einstein would strongly disagree with this statement. There is no way to "cheat" the system, as far as he was concerned (and, as far as I can tell, every physicist agrees with him).

I actually have studied a bit of both special and general relativity. It denies time travel (in an absolute sense - there are subjective frames of different time-rates, but that's not time travel. For example, you can put an atomic clock in a very fast plane, fly it around for awhile, and then bring it back to another atomic clock, and the one in the plane is measurably behind - it was moving more quickly, its time rate was slower) pretty much completely. It also pretty much denies space warps as well. It does leave black holes a little bit fuzzy. There's a mathematical model called an "Einstein-Rosen Bridge" that describes something like a wormhole linking a black hole in our time-space to a black hole in another time-space. I don't know enough about that part to know if two black holes could be linked in our time-space, but then you have the problem of building something capable of going into a black hole without being destroyed.

 

[RickG]

"Why do they call it Ovaltine? I mean the jar is round, the glass is round, shouldn't it be Roundtine?"

http://www.glossynews.com/artman/pub...tine-906.shtml

And when I stir the stuff, there really is a vortex, and a gravitational pull towards the center of the glass...

Hell, next I'll be using Bosco and bending time along with George Costanza...

 

[D-EJ915]

So this is an example of the bowling-ball on a wrestling mat thing?

 

[GanChan]

Quote:

Originally Posted by D-EJ915 So this is an example of the bowling-ball on a wrestling mat thing?

WWF Science Theatre:

"Whatcha gonna do
When Einsteinmania
warps time and space around YOOOO?"

 

[strohmie]

I have to give props for my boys at the University of Maryland for being involved with this study.

Go Terps!...WIN A GAME FOR ONCE!

 

[Megaptera]

Quote:

Originally Posted by D-EJ915 So this is an example of the bowling-ball on a wrestling mat thing?

It's an elaboration on it, you could say. This goes a big way towards proving one of the fine details; if it had been shown to not be the case, then that'd have been a hole in the theory that'd need explaining.

So the metaphor: Let's say you've got your mat, with your bowling ball on it -- the standard metaphor is that the bowling ball sinks and stretches the mat, and behold, you have an idea of what gravity 'looks' like. What this release is saying that if the bowling ball (something with mass) is spinning, the mat (the space that the mass is in) gets twisted with it. Which seems obvious, but remember we're not talking about rubber mats, we're talking about... well, I don't think there's really any good way for us to understand it. The whole thing about gravity is that it's like drawing something on a sheet of graph paper and then watching the graph grid wrap around what you drew.

It's easy to get a simple mental picture of this, but nobody is 100% certain of every factor involved or what effect those factors have. This report is cool because now we're a bit farther away from 0%

 

[wallijonn]

http://www.technewsworld.com/story/32650.html :
Quote:

In 1918, two years after the General Theory was published, researchers predicted that the gravity produced by massive rotating objects (such as planets, stars and black holes) actually should drag nearby space-time around with them. Consider the orbits of the planets. We think of them as circular or elliptical, but according to the General Theory, they actually are traveling in straight lines: It is the very space containing them -- the fabric by which they exist -- that is curved by the sun's gravity.

emphasis mine.

A more detailed analysis: http://www.2think.org/t000104284.shtml

My question is: If planets are travelling in a straight line - are they rotating? I say no; it is the curving of space which gives the illusion of rotation. That 'perspection' (perspective + -ion (a state of being)) is what we call time. Translation: We perceive time because we perceive space; we perceive space because we perceive time.


.

 

[Megaptera]

Quote:

Originally Posted by wallijonn My question is: If planets are travelling in a straight line - are they rotating? I say no; it is the curving of space which gives the illusion of rotation.

Well, bear in mind that there's a difference between a body's orbital motion and its rotational motion. Rotation is the spin a body has along its axis (the movement that lets us mark days off the calendar), and it's not the same thing as its orbital motion (which lets us mark years). So here's the thing about orbital revolution: it is, basically, just falling in a straight line through bent space, but you still wind up more or less where you started once you've made a complete revolution. That's relative to the sun, other stars, and other big things out there that aren't noticeably affected by the sun's gravity. Which means that it's more accurate to say that the curving of space gives us the reality of revolution, but the illusion of travel in a straight line