What is the speed of gravity?

[newtonian]

The speed of light? Or faster? Or instantaneous?<br /><br />I thought it was the speed of light, but jatslo in another thread indicated it was unknown or not proven.

 

[jatslo]

infinite, or finite

 

[newtonian]

jatslo - I know we are still learning about gravity, but I didn't realize it was that uncertain!<br /><br />On the possibility of instantaneous (aka infinite), our literature notes:<br /><br />"A recently published book entitled The Universe Explained admits that ‘gravity is the most familiar, yet the least understood, of nature’s forces.’ It adds: “Gravitational force seems to travel across empty space instantly, without any obvious means of doing so. In recent years, however, physicists have begun to speculate that gravity might travel in waves made of particles called gravitons . . . But no one is quite certain of their existence.” - "The Watchtower," 4/15/01, p. 5<br /><br />That was, however, over 4 years ago. There was a more recent experiment which I thought confirmed gravity traveled at the speed of light.<br /><br />I will, of course, research these matters. <br /><br />But feel free to post what you can find!

 

[jatslo]

Right, waves and particles measured by magnitude and/or direction through a medium.

 

[newtonian]

Jatslo - Score one for c as speed of gravity, Einstein cited by Encarta 2003:<br /><br />EINSTEIN'S THEORY OF RELATIVITY <br /><br />In 1915 Einstein formulated a new theory of gravitation that reconciled the force of gravitation with the requirements of his theory of special relativity. He proposed that gravitational effects move at the speed of c. He called this theory general relativity to distinguish it from special relativity, which only holds when there is no force of gravitation. General relativity produces predictions very close to those of Newton's theory in most familiar situations, such as the moon orbiting the earth. Einstein's theory differed from Newton's theory, however, in that it described gravitation as a curvature of space and time.<br /><br />Microsoft® Encarta® Encyclopedia 2003. © 1993-2002 Microsoft Corporation. All rights reserved.<br /><br />To repeat the crucial phrase for emphasis:<br /><br />"He proposed that gravitational effects move at the speed of c."<br /><br />If I remember correctly, Newton proposed it was instantaneous.

 

[newtonian]

jatslo - score 2 for c:<br /><br />http://news.bbc.co.uk/2/hi/science/nature/2639043.stm<br /><br />Wednesday, 8 January, 2003, 13:55 GMT <br />Einstein proved right on gravity<br /><br /> It all adds up: Albert Einstein would be pleased<br /><br />By Dr David Whitehouse <br />BBC News Online science editor <br /> <br /> The speed of gravity has been measured for the first time, revealing that it does indeed travel at the speed of light. <br />It means that Einstein's General Theory of Relativity has passed yet another test with flying colours. <br /><br />The measurement was made by Ed Fomalont of the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, and Sergei Kopeikin of the University of Missouri, in Columbia, both US. <br /><br />Writing in New Scientist magazine, they say: "We became the first two people to know the speed of gravity, one of the fundamental constants of nature." <br /><br />Higher dimensions <br /><br />Isaac Newton believed the influence of gravity was instantaneous. Later, Albert Einstein assumed it travelled at the speed of light and built his 1915 General Theory of Relativity around that assumption. <br /><br />If gravity travelled at the speed of light it would mean that if the Sun suddenly vanished from the Solar System, the Earth would remain in orbit for about eight minutes - the time taken for light to travel from the star to our planet. Then, in the absence of gravity, Earth would move off in a straight line. <br /><br />Modern researchers say that knowing the speed of gravity is important in the study of branches of cosmology where the Universe has more spatial dimensions than the usual three. <br /><br />Some of those theories suggest that gravity could take a short cut through higher dimensions and so appear to travel faster than the speed of light. <br /><br />Jupiter's help <br /><br />To measure gravity's velocity, Kopeikin determined that it could be de

 

[jatslo]

They are both right and both wrong, because their quantifications are fragmented, and do not account for viscosity. For example, a zero rest mass must move at (c), or (v) relative to (c) in the medium. Both theories break down in quantum and the final frontier. If time is a factor in determining distance, then distance is exponentially flawed the further your object is from the Earth’s Sun. Essentially, space-time has varying degrees of viscosity created from whatever makes up whatever part of the universe, and light travels through these mediums at relative different speeds and/or velocities, which screws with time.<br /><br />It is ignorant to think that light travels at a constant rate of 186,000 miles per second for the entire 50-billion light years. Where there is zero viscosity: electromagnetism and gravity will intensify to instant speeds and slow as he ether thickens. Can you find density experiments involving Voyager, Galileo, and/or Cassini?

 

[jatslo]

Yeah, that is relative to position and viscosity. We are lucky to have a Jupiter big brother. Yep, electromagnetism and gravity most definitely travel a relatively the same speeds and velocities in one point in space-time, which is finite or infinite. Ask them if time is a factor in there conclusion, and then toss some viscosity between the quasar and here and we have a problem pinpointing the position of the quasar.

 

[newtonian]

jatslo - You are referring to the speed of light which does vary according to the medium through which it passes.<br /><br />That is very interesting - do you have links on this?<br /><br />Are you suggesting gravity speed also varies according to the medium through which gravitons, if they exist, travel?<br /><br />Back to recent scientific links with other thinkers involved, two links are right here at SDC. See the latter one in this link, which links to the earlier one:<br /><br />http://www.space.com/scienceastronomy/gravity_speed_030116.html<br /><br />Jude 13 indicates that some stars, probably specifically black holes, are in eternal darkness with no set course. Having no set course may mean escaping the gravity of our universe.<br /><br />If gravity propagates at c, and if inflationary models are correct about early expansion faster than c, than the model hinted at in Jude 13 would be very likely correct.<br /><br />The latter link raises the possibility that gravity is faster than c but not instantaneous.<br /><br />The experiment admittedly had a 20% error factor.<br /><br />Interesting photo in the latter link, btw.

 

[jatslo]

Nope! I worked it out in my quantum brain

 

[jatslo]

It is possible that gravity prorogates faster through the medium. There are to many mediums between here and there to ascertain distance by time utilization. It is okay though; I doubt we will be going to a star any time soon.

 

[jatslo]

It is possible that gravity proprogates slower through the medium as well; it would depend on the varibles involved: Magnitude and/or velocity.<br /><br />Nuclear implosions/explosions originate from rest, but light is far faster that pressure, but that may just be a timing issue with respect to the temporary creation of a vacuum.

 

[newtonian]

jatslo - You are losing me - perhaps because I am tired.<br /><br />We may not fully appreciate the gravity of the matter!<br /><br />If we only knew the cause of gravity, the mechanism involved, it would help.<br /><br />Which then would help us identify what gravity is.<br /><br />Which would then explain how it travels.<br /><br />You are correct that if gravity travels at c then it is indeed effected by time - as is all travel to my knowledge.<br /><br />I will be researching this. Feel free to add any input.<br /><br />Thank you for your posted input - it is both stimulating and boggling my brain!<br /><br />I am wondering if it has anything to do with quark spin properties and propagation of said spin.<br /><br />I do believe quarks propagate gravity - am I correct?<br /><br />Or is it simply, as I believe Einstein visualized, bending the space-time fabric due simply to mass?

 

[jatslo]

I know how to make self-sustaining vector and scaler quantities of artificial gravity without spin, and without the use of an anti-universe.

 

[newtonian]

jatslo - Please post details. However, I need to go to sleep and work long hours tomorrow so won't be able to respond 'til Wednesday.<br /><br />I am very interested in quantum effects, scaler fields, etc. - but you will need to simplify since that is not my field!<br /><br />I do know Linde appealed to scaler fields for the origin of our universe and also inflation theory.<br /><br />Clearly, gravity is involved in our universe's origin.<br /><br />Signing off for now - look forward to your response.

 

[jatslo]

If I can construct artificial gravity before someone else, then you can read about Jatslo in the news, and if someone else succeeds before Jatslo, then I will tell you how they did it.

 

[raghara2]

<br /><br />http://www.metaresearch.org/cosmology/speed_of_gravity.asp<br /><br />This is nice summary.

 

[siarad]

If gravity travels at c & is dented spacetime then the dent must be different in the direction of travel than behind.<br />Has any measurement been made of this nonlinearity in respect of the suns travel or any high g object?

 

[igorsboss]

<font color="yellow">jatslo - score 2 for c:<br />http://news.bbc.co.uk/2/hi/science/nature/2639043.stm <br />Wednesday, 8 January, 2003, 13:55 GMT <br />Einstein proved right on gravity <br /></font><br /><br />Sorry. This particular conclusion was later determined to be incorrect by peer review. Although it was a very good effort, it turns out that the experiment only measured the speed of light, not the speed of gravity. I don't have a source for this yet, but I recall this from previous SDC posts.<br /><br />Score 1 for c. All we have to go on here is Einstein's word. We don't yet know the speed of gravity.

 

[newtonian]

igorsboss - I had already posted this link, which give the critique of the earlier interpretation:<br /><br />http://www.space.com/scienceastronomy/gravity_speed_030116.html

 

[newtonian]

Igorsboss - I believe the dispute is whether relativistic effects of time dilation + length contraction were the factor being measured rather than the effect of the limit of the speed of gravity.<br /><br />Scientific American, 4/03, questions the experiment allegedly confirming gravity speed is c, e.g.: <br /><br />“Yet most relativity researchers are skeptical.<br />“It’s a beautiful experiment that gives a very<br />nice new confirmation of general relativity,<br />but it’s still unclear whether it’s testing the<br />speed of gravity,” says Steven Carlip of the<br />University of California at Davis.” <br /><br />Concerning Kopeikin and Fomalont’s experimenet, Sciam reports:<br /><br />Last September they put their plan into action<br />when Jupiter passed close to the line of<br />sight between Earth and a quasar. The quasar<br />image scooted 1,300 microarcseconds across<br />the sky—with a 50-microarcsecond skew, just<br />as expected from relativistic effects.<br />So far, so uncontroversial. The fun begins<br />when you ask which relativistic effect was operating.<br />There are oodles of possibilities, and<br />Einstein’s notoriously subtle equations do not<br />specify which mathematical term corresponds<br />to which physical effect. Kopeikin and Fomalont<br />contend that the dominant effect was the<br />propagation of gravity. As Jupiter travels, its<br />gravitational force on the ray varies, and the<br />variation takes a little while to travel through<br />space to the ray. To isolate this effect, the scientists<br />constructed an alternative version of<br />relativity, in which cg could differ from c.<br />They were then able to infer a value for cg<br />from the data, without presuming it. The two<br />c’s turned out to have the same numerical value,<br />with a precision of 20 percent.<br />But others, notably Clifford M. Will of<br />Washington University, take a different approach<br />to extending relativity and attribute<br />the observed skew to the better-known relativistic<br></br>

 

[newtonian]

siarad - I don't know how we would measure the curvature of spacetime in your scenario.<br /><br />By circular reasoning, of course, one could measure the effect of gravity changing due to velocity and infer this caused a change in the curvature of spacetime - but this would, of course, be circular reasoning.<br /><br />To my knowledge, the strength of gravity is not effected by sub-light variable speed or velocity (or acceleration for that matter).<br /><br />If gravity is similar to light, such that a graviton is similar to a photon, which I doubt btw, then one would expect the wavelengths of gravitational variation would be shifted similar to red or blue shifting of light due to speed.<br /><br />I will start another thread on this since it is a different area of scientific research.

 

[newtonian]

ragharA2 - Excellent link - if accurate, then gravity does not travel at the speed of light.<br /><br />I need to study it better though.<br /><br />What is your conclusion as to the speed of gravity in view of that excellent summary?

 

[formulaterp]

<font color="yellow">ragharA2 - Excellent link ... What is your conclusion as to the speed of gravity in view of that excellent summary?</font><br /><br />Ummm ... Newtonian? You do realize that Van Flandern and the folks at metaresearch aren't exactly playing with a full deck, right? Take everything you read there with a grain of Lot's wife.

 

[newtonian]

formulaterp - Better or worse than Halton Arp? Japanese Raelians?<br /><br />Seriously, in view of our state of knowledge on gravity, even way outside the box input helps for critical analysis - i.e. questioning assumed models or factors.<br /><br />The link proposed propagation of gravity FTL but a limit of c for speed of gravity waves.<br /><br />It does sound like a way out model.<br /><br />I prefer to examine input on the basis of content rather than on the basis of who contributed the content.