Gravity, does it have speed?

StarLord

StarLord

Senior Member
Messages
3,187
Re: Gravity, does it have speed?

Lucidus,

<div class='quotetop'>QUOTE(\"lucidus\")</div>
Really? I haven't heard that. Could you provide a link? If that is true, then the effect would seem to occur immediately.[/b]
Click to expand...

try:
http://www.ldolphin.org/vanFlandern/gravityspeed.html

I am surprised Iggy hasn't been all over this.

Jim, I am no expert but perhaps a math wiz could double check that link and see if the math is sound.

It could be that Tom Van Flandern and you might disagree on this point.
 
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iooqxpooi

Member
Messages
173
Re: Gravity, does it have speed?

ACK! You crazy quantum physicists...Remember RELATIVITY! The gravitational field is curved space-time, (I saw a picture of that as I was scrolling down) according to Relativity. The quantum physicists, though, think that gravitational fields are composed of bodies emitting gravitons...which have NO MASS and emit a gravitational force...They think that they travel at the speed of light and pass through dimensions and blah blah blah...Kinda sounds like me trying to get around the fact that I am WRONG. (My first attempts to find a proof of my own of the pythag. theorem) Anyway, as you can see, I am a firm relativity believer...Thus I can tell you that gravity does not have speed...And oh by the way, if the sun dissappeared, the earth would not go in a straight line. Only if every body that could effect the earth dissappeared would the earth go in a straight line...And if that happened it would still come to a stop unless the plasma in space dissappeared too. :)
 
I

iooqxpooi

Member
Messages
173
Re: Gravity, does it have speed?

<div class='quotetop'>QUOTE(\"Chronodynamic Jim\")</div>
I'm Sorry, Most of you are wrong.
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First off, light IS a electromagnetic wave, so therefore, speed of electromagnatism = speed of light. The effect of magnatism travels at the speed of light.
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Secondly, Gravity doesn't have a speed really. light and electromagnatism are made up of exchange particles called photons that travel at the speed of light. Gravity is theorized to be composed of exchange particles called gravitons, though no one has observed them, and there's not a lot of hope that anyone ever will.
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The catch is that Gravity is not a classic force field like Electromagnatism, the Strong and the Weak forces. According to General Relativity, Gravity is best thought of as an effect. The typical illustration is that of a bowling ball resting on a sheet of rubber. The bowling ball would warp the surface of the rubber sheet as a result of its weight. A marble rolling on the warped surface of the rubber sheet would follow a curved path similar to the path of the Earth as it orbits the Sun.
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Gravity is simply the warping of the fabric of space caused by the presence of mass. If we Imagine the rubber sheet without a bowling ball it would be flat. As we rest the bowling ball on the rubber sheet a depression is formed, small at first and confined to the immidiate vicinity of the bowling ball. But as the bowling ball sinks deeper, the depression spreads outward from the center of the bowling ball.
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The same thing would happen with the Sun. The spreading effect of the warping of space in the presence of mass is the closest you'll ever come to the \"speed\" of gravity. That being said, your question is what exactly is that speed? Newton thought as some of the posters here thought, that this effect would make its presence felt instantaneously across any distance. General Relativity predicts though, that this effect decreases at the square of the distance and does so at precisely the speed of light.
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Ergo the answer to your question, Gravity, does it have speed? is Yes, and that speed is 186,282 miles per second.
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A more interesting question is, Why does the effect of gravity propigate at the speed of light? ?
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One last point before I go. In the above illustration regarding the rubber sheet and the bowling ball to explain gravity (an illustration I did not come up with BTW), the bowling ball represents the Sun, the rubber sheet represents the fabric of space-time, and the marble represents the Earth. ?
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What does the pull of gravity on the bowling ball and marble represent?
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Why do we invoke gravity as an integral part of an illustration explaining gravity?[/b]
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Looks to me like you just got yourself a Theory of Everything. Crazy scientists, always looking at the complex picture when they could just make gravity the speed of light and make gravity unified with EM! ;) :p


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Ah yes, I forgot to read the bulk of your post. Let us say that we have a sheet of paper. You put a ball on that paper. Tell me, if the ball weighs x kg and the paper is mn square meters in area, then how much of the paper is effected after q seconds? (q>0) ALL OF IT! Test it out. The magnitude just goes up as the time goes up, or it is directly proportional to time. If mn=infinity, then guess when x has to equal to effect all of it? Anything greater than 0! So long as x>0, the entire are of the paper will be effected. I discovered this during the summer as I was trying to test my reverse gravity theory. ;)
 
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iooqxpooi

Member
Messages
173
Re: Gravity, does it have speed?

And there is an easy way to test it...

Let s=speed
t=time that larger body existed
t1=time that it took for smaller body to fall out of orbit
d=distance

d/(t1-t)=s

But, of course, no measurement can be exact. :(
 
Chronodynamic Jim

Chronodynamic Jim

Junior Member
Messages
116
Re: Gravity, does it have speed?

Oh Yeah?
Well let G = Speed of Gravity
c = Speed of light

G*1=c

That proves that the speed of gravity is equal to the speed of light! ;)

PS hey Iggy!
 
StarLord

StarLord

Senior Member
Messages
3,187
Re: Gravity, does it have speed?

Imagine having a large electro magnet and it is spinning. There are all sorts of pcs of metal being held in place. Cut off the current. What happenes to those pcs of metal, do they fall straight down towards the floor or what?
 
S

sam mower

New Member
Messages
16
Re: Gravity, does it have speed?

imagine having your own apartment, you come home from work and turn up the light.
what happens when you turn on the switch? is the place lit instantly or what?
 
StarLord

StarLord

Senior Member
Messages
3,187
Re: Gravity, does it have speed?

<div class='quotetop'>QUOTE(\"iooqxpooi\")</div>
ACK! You crazy quantum physicists...Remember RELATIVITY! The gravitational field is curved space-time, (I saw a picture of that as I was scrolling down) according to Relativity. The quantum physicists, though, think that gravitational fields are composed of bodies emitting gravitons...which have NO MASS and emit a gravitational force...They think that they travel at the speed of light and pass through dimensions and blah blah blah...Kinda sounds like me trying to get around the fact that I am WRONG. (My first attempts to find a proof of my own of the pythag. theorem) Anyway, as you can see, I am a firm relativity believer...Thus I can tell you that gravity does not have speed...And oh by the way, if the sun dissappeared, the earth would not go in a straight line. Only if every body that could effect the earth dissappeared would the earth go in a straight line...And if that happened it would still come to a stop unless the plasma in space dissappeared too. :)[/b]
Click to expand...

Sorry Iggy, but I think that Van Flandern has sated even your mathematical lust for formulae. Even though gravity is considered a 'weak' force, it is possibly one of the strongest forces in the Universe. While the force may not be observed like light, it is more that obviously at work keeping your Capt. Crunch firmly planted to your table. Van Flandern's math shows that the speed of cessation is insanely faster than that of light.

Iggy, I would be interested to know what your calculator says about 93,000,000 miles and a speed of 2 x 10 to the power of 10 c. Numbers like that point to darn near instantaneous if I am not mistaken.

As far as the Earth sailing off into space in a straight line when that force is cut, are you saying that the earth is going to move in a curved line? If so, explain how that is possible when all gravitational forces from the sun no longer affect the planet and no longer cause it to adhere to a curved orbit and the planet is left to its own devices. Remember its spinning like a top at some 5000 mph.
 

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