First speed of gravity measurement revealed

NewScientist.com ^ | 01/07/2003 | Ed Fomalont and Sergei Kopeikin

[Aracelis]

the time it takes the bowl of spaghetti to hit the floor is directly proportional to the time it takes for the dog to arrive at the spill and clean it up and inversely proportional to the time it takes for mom to grab a towel and clean it up!

Also, there is no relationship between the amount of spaghetti that spilled and the extent of the stain. The stain will spread to a surface area of 2304 square-inches regardless. :^)

[Aracelis]

Can somebody please get Bill Nye the Science Guy to explain this so I can understand it?

ROFL! These guys just love to out-science each other. As long as your feet stick to the floor, don't worry about it (assuming they are not stuck in a pile of spaghetti).

[Physicist]

Not all motion is relative. Acceleration is absolute.

LOL. As I wrote my post, I wondered whether some lawyer was going to come along and say that acceleration is not relative. (That doesn't make it absolute, either, but that's a longer story.) The poster wasn't talking about acceleration, but about velocity.

[RightWhale]

I've always thought of gravity as a field of some kind even before learning about fields as a mathematical construct. Never worried about the speed of propagation of a change in field, still don't, but it looks like somebody ought to, so it is good to know that such changes propagate at the speed of light. Waiting for news of the gravitational blue shift.

[aruanan]

Here's a link to a response to the news item at the top. It contains some interesting revelations about the experimenter's methods:

Abstract. New findings announced today by S. Kopeikin are invalid by both experimental and theoretical standards. They do a disservice to science in general and the advancement of physics in particular because the announced findings do not represent the meaning of the actual experimental results and cannot possibly represent the physical quantity heretofore called "the speed of gravity", which has already been proved by six experiments to propagate much faster than light, perhaps billions of times faster. 

[MeekOneGOP]

Interesting. Thanks for the post...

[aruanan]

Whoops. Here's the DIRECT link to a response to the news item at the top. It contains some interesting revelations about the experimenter's methods:

Abstract. New findings announced today by S. Kopeikin are invalid by both experimental and theoretical standards. They do a disservice to science in general and the advancement of physics in particular because the announced findings do not represent the meaning of the actual experimental results and cannot possibly represent the physical quantity heretofore called "the speed of gravity", which has already been proved by six experiments to propagate much faster than light, perhaps billions of times faster. 

[Mr. K]

GRAVITY!
It's not just a good idea...
Its THE LAW!




(oooh I am glad I was first with that one)

[aruanan]

Never worried about the speed of propagation of a change in field, still don't, but it looks like somebody ought to, so it is good to know that such changes propagate at the speed of light.

See this link for a rebuttal of this paper referred to at the top.

[ThinkPlease]

I'm going to agree with Aruanan on this one. Kopeikin has released a press release on something that hasn't cleared peer review yet. It's extremely frustrating when someone tries to cheat the peer review process. At least have the good sense to wait until your paper has been accepted for publication!

space.com notes that the article is still in the peer review process because of problems from the reviewer.

On the other hand, if it is shot down, it is a vindication of the peer review process, something that Aruanan claimed was part of the corrupt scientific establishment just the other day.

[RightWhale]

part of the corrupt scientific establishment

Whoa!!!! Multimode attack!!!! Shields up!!!!

[FreeTheHostages]

Sorry I'm late to the thread! I had to come all the way over from the "I-told-you-so" Department.

LOL. :D

[FreeTheHostages]

ROFL. Heck, you can see that Gravity bends Light by simply holding your thumb between your eye and a light source and looking at the edges, however, this phenomenon doesn't happen when Light is traveling at slower speeds because so few Gravitons are being emitted.

Ah, c'mon, Dan, no response to this? PLEASE PLEASE I enjoy reading your responses. And if ever there were a highly inflexible, NON-bended straight line, Southhack's given you one.

Now, some will say it's a cruel sport. It's too easy. It's like hunting elephant in a zoo. But I say: Go for it!

[FreeTheHostages]

Looks like somebody's forgotten that all motion is relative.

Hmm, I hate to be niggling, but don't you think you presume to much in this case by using the word "forgotten"?

[metacognative]

I was told in high school that gravity didn't exist...the world sucks. Since then, coomon sense tells me that gravity does not 'pull', it pushes. HOWZAT?

[aruanan]

On the other hand, if it is shot down, it is a vindication of the peer review process, something that Aruanan claimed was part of the corrupt scientific establishment just the other day.

Your characterization of what I said "just the other day" is an over-generalization. The funny thing about the reception of Kopeikin's interpretation of the results of his experiment is that it ignores previously published data* already subject to peer review on a very controversial subject that present quite a different outcome.

*T. Van Flandern and J.P. Vigier (2002), “Experimental Repeal of the Speed Limit for Gravitational, Electrodynamic, and Quantum Field Interactions”, Found.Phys. 32, 1031-1068.

T. Van Flandern (1998) , “The speed of gravity – What the experiments say”, Phys.Lett.A ,/em>250, 1-11.

[aruanan]

part of the corrupt scientific establishment

See what was actually said. You know, trust, but verify?

[who_would_fardels_bear]

"Perhaps there is a minimum distance -- a quantum of space -- and a minimum amount of time -- a quantum of time"

If there is a quantum of space and a quantum of time this could be the soucre of the uncertainties of quantum mechanics: since a particle would have to jump from one point on some invisible grid to another, there is uncertainty about it's position when it is jumping from one point to the other.

The bad news is that if we find out that space and time is quantized, it could be because we are all part of some very sophisticated "first-person shooter" game driven by a computer with a fixed clock speed (the time quanta) and a fixed resolution (the space quanta)!

Where's my missile launcher?

[Chemist_Geek]

First, it would be *really* hard to vibrate a mass large enough to produce any non-trivial amount of gravity.

Then, how would one modulate the baseband? Or would we have to use CW?

[RightWhale]

how would one modulate

Mass has to move. Perhaps a rotating double star would give off CW strong enough to detect. Perhaps Jupiter is massive enough and close enough for the instrument to pick up something.