Planetarion Forums

Gayle29uk · 8 Jan 2003, 10:21

New scientist have an article detailing the first ever measurement of the speed of gravity (sorry Newton, Einstein was right again), Obviously this evidence that gravity is not instantaneous makes it even more likely that gravity is indeed wave based (someone page Jenny to fill in the details please

). Taking this into account we might get to see hovercars in our lifetime \o/

/me wants a hovercar

xtrasyn · 8 Jan 2003, 10:48

I feel smug for knowing this all along

everything in this ****ing universe is like water

wheter it be time, space, energy or gravity.

MrL_JaKiri · 8 Jan 2003, 13:38

From what the article said (although I wouldn't really trust New Scientist overmuch; it's become more of a political journal) I'd say that a Grand Unified Theory is further away, because of the increased difficulty in accounting for the Calibi-Yau spaces, which could alter said speed of gravity (obviously I'm talking about M-theory here, as I can't recall any other reasonably developed stab at a GUT).

What it does do is make a graviton (exchange particle of gravity) more likely, as a graviton is theorised to be a massless particle which travels at the speed of light. Hey, doesn't gravity travel at the speed of light? WHY YES!

Gayle29uk · 8 Jan 2003, 14:02

Quote:

Originally posted by MrL_JaKiri
From what the article said (although I wouldn't really trust New Scientist overmuch; it's become more of a political journal) I'd say that a Grand Unified Theory is further away, because of the increased difficulty in accounting for the Calibi-Yau spaces, which could alter said speed of gravity (obviously I'm talking about M-theory here, as I can't recall any other reasonably developed stab at a GUT).

It may be the best version but that still doesn't mean it's right. As it's basically Klein bottles on acid it's had a fair amount of time (80 years?) to mature as a theory so it should be fairly ripe.

Quote:

What it does do is make a graviton (exchange particle of gravity) more likely, as a graviton is theorised to be a massless particle which travels at the speed of light.

I prefer the wave/particle duality theory myself, same as in light.

MrL_JaKiri · 8 Jan 2003, 14:05

Quote:

Originally posted by Gayle28uk
It may be the best version but that still doesn't mean it's right. As it's basically Klein bottles on acid it's had a fair amount of time (80 years?) to mature as a theory so it should be fairly ripe.

I prefer the wave/particle duality theory myself, same as in light.

M-theory's only been in the works for about 20 years, and in its current state about 5 or so.

As for wave/particle duality, that applies to everything.

Mong · 8 Jan 2003, 14:20

Pavil, why do you have to be such a nob ALL THE TIME?

*sigh*

Anyway, can one of the resident brains here explain what Gayle said; "Taking this into account we might get to see hovercars in our lifetime"?

How would it work? Something to disrupt the graviton(?) waves, thus evading gravity. Or something to synchronise? I dunno, cos I never did physics or anything scientific past GCSE

M.

Gayle29uk · 8 Jan 2003, 14:22

Quote:

Originally posted by MrL_JaKiri
M-theory's only been in the works for about 20 years, and in its current state about 5 or so.

String theory has been around since the 60s at least and was developed from the work of Klein in the 20s (if I remember right). Admittedly the development to superstrings and then m-theory are more recent but the concept goes back at least 80 years.

And this is where I stop as I know nothing more about the subject.

Back on the REAL topic though, I STILL WANT A HOVERCAR!

Gayle29uk · 8 Jan 2003, 14:25

Quote:

Originally posted by Mong
Anyway, can one of the resident brains here explain what Gayle said; "Taking this into account we might get to see hovercars in our lifetime"?

How would it work? Something to disrupt the graviton(?) waves, thus evading gravity. Or something to synchronise? I dunno, cos I never did physics or anything scientific past GCSE

M.

Having proved that gravitons exist and travel at the speed of light we're one step closer to actually generating them (or neutralising them). I could be a bit optimistic about this happening in our lifetime though

We need Jenny so someone who understands it can argue with MrL about this

MrL_JaKiri · 8 Jan 2003, 14:37

Quote:

Originally posted by Mong
How would it work?

No idea, but knowing how gravity works would be the first step towards making one.

And I promised I'd make one for nod. Well, a back to the future style hoverboard anyway.

ParraCida · 8 Jan 2003, 15:47

Quote:

Originally posted by xtrasyn
I feel smug for knowing this all along

everything in this ****ing universe is like water

wheter it be time, space, energy or gravity.

how about light?

and btw, time does not exist.

MrL_JaKiri · 8 Jan 2003, 16:46

Quote:

Originally posted by xtrasyn
I feel smug for knowing this all along

everything in this ****ing universe is like water

wheter it be time, space, energy or gravity.

Space time isn't a wave

SepH · 8 Jan 2003, 16:55

Quote:

Originally posted by MrL_JaKiri
No idea, but knowing how gravity works would be the first step towards making one.

And I promised I'd make one for nod. Well, a back to the future style hoverboard anyway.

twould be nice if we could create artificial gravity aswell

ofc hoverboards* > hovercars > *

*back to the future anyone?

MrL_JaKiri · 8 Jan 2003, 17:09

Quote:

Originally posted by SepH

Quote:

Originally posted by MrL_JaKiri
No idea, but knowing how gravity works would be the first step towards making one.

And I promised I'd make one for nod. Well, a back to the future style hoverboard anyway.

back to the future anyone?

Intervention · 8 Jan 2003, 17:19

Quote:

Originally posted by Gayle28uk

/me wants a hovercar

www.firebox.com -> expensive stuff

MrL_JaKiri · 8 Jan 2003, 17:22

Quote:

Originally posted by Intervention
www.firebox.com -> expensive stuff

My hovercars will be cheap and plentiful!

To make anyway. I'll charge you through the nose.

SepH · 8 Jan 2003, 18:56

Quote:

Originally posted by MrL_JaKiri
back to the future anyone?

[/quote]

allright, im gonna slap myself a couple of times now

sayonara · 8 Jan 2003, 19:14

I was so hoping this bit of news would eventually come to light.

It means those smug "let's call space ether even though space will do fine as a name" tossers will have to face the fact that pretty much everything in the universe has a finite velocity, and that they are talking crap.

Huzzah!

sayonara · 8 Jan 2003, 19:17

Quote:

Originally posted by Intervention
www.firebox.com -> expensive stuff

Did you mean this?

http://www.firebox.com/index.html?di...roduct&pid=415

W · 8 Jan 2003, 21:50

In some experiments (already performed, basic stuff) the speed of gravity is the same as the speed of light. In other experiments, gravity propagates instantaneously. This is not new.

Quote:

From that they worked out that gravity does move at the same speed as light. Their actual figure was 0.95 times light speed, but with a large error margin of plus or minus 0.25.

I have to wonder; is that the standard deviation? 2x standard deviation? What? Isn't 25% pretty big an error estimate? Being that big, isn't it more correct to have a geometric error estimate, not a linear one? (ie not +/- error, but *-/ error)

Not that there's any conventional theory to get the equations they used. Most likely the result of their "experiments" was allready given from the theory used to deduct it from the raw data.

And since I can't post on a physics topic without telling you all what I think is more likely:

I doubt that gravity, or even the strong or weak nuclear forces, work in any way like the electromagnetic forces do. It seems a stupid mistake to do to assume that the virtual particles of these forces are anything like photons. I doubt such particles can be said to "travel" at all, not even in the degree that light particles do.

acropolis · 8 Jan 2003, 22:31

Quote:

Originally posted by W
And since I can't post on a physics topic without telling you all what I think is more likely:

I doubt that gravity, or even the strong or weak nuclear forces, work in any way like the electromagnetic forces do. It seems a stupid mistake to do to assume that the virtual particles of these forces are anything like photons. I doubt such particles can be said to "travel" at all, not even in the degree that light particles do.

I tend to agree.

I would say that by relativity, the entire concept of "instantaneous travel" is simply nonsense, so to that extent this result is unsurprising, but I see nothing in there that would indicate that gravity "travels" at all, at the speed of light or otherwise.

I would guess that if instead of finding out that gravity travels at .95 +/- .25 they found that it traveled at .5 +/- .25, this study would have just been ignored anyway.

MrL_JaKiri · 8 Jan 2003, 23:40

Quote:

Originally posted by acropolis
I would guess that if instead of finding out that gravity travels at .95 +/- .25 they found that it traveled at .5 +/- .25, this study would have just been ignored anyway.

The experiment would be refined and repeated to test if the value of the speed of gravity was indeed in the region given, as that would be quite a deviation from predicted.