Gravitation's propagation speed.

Hi, I have been lurking at ATS for a while, thought i'd try kicking off a new thread.

Basically, we know the speed of light, but gravitation is not electromagnetic.

Has anyone done any research to find out the speed of gravitation?

I mean, if a star was suddenly ripped from its solar system by a black hole travelling past at 99.9999% lightspeed, how long would it take for the change to be "noticed" at the furthest of the stars satellites?

Note: I am aware that a black hole travelling that fast would have nearly infinite mass and so it would probably have more effect than the stars absence but I'm only using this as a (poor) metaphor to describe my point.

I have seen some debate on this.. My opinion, albeit not in any way learned, is that gravity is a function of spacetime. Since Spacetime itself can travel much faster the light, then we currently have no way of measuring the actual speed.

I'm no scientist, but I have come across certain information. One that says that even you and me have gravitational fields, they are just so minuscule you can't actually notice a difference. I guess gravitational "speed" would depend on the size of the object, ie, the suns gravitational "speed" will be greater than the earth's.

If this is not what you mean, just ignore my uneducated response

I thik this may be a good examle








we need to understand what gravity is fully . before we can measure it . Is it a force a byproduct a motion etc .


Then we can measure a graviTON .

Pesky Gravity . measuring it is ihard


looking for gravity wave here no luck


www.ligo.caltech.edu...

As a fellow lurker and academic, I'll bite.

It's true that the speed of light originated from EM, but because there is nothing that is known to travel faster than light in a vacuum, so this is accepted as the maximum speed of propagation. Einstein's general relativity is currently the most accepted description of gravity we have, and is defined such that nothing can propagate faster than light in vacua. Anything that has a cause can be connected to an effect that happened close enough and distant in the past enough that a light signal through a vacuum could reach it. Otherwise two observers moving at different relative speeds would disagree about which event happened first, and thus one event would not be causally connected to the other. I suggest a look into space-time intervals.

-Balboa

reply to post by rogerstigers

Since Spacetime itself can travel much faster the light, then we currently have no way of measuring the actual speed.

I am trying to concieve how spacetime travels. I would have thought spacetime is the substrate against which travel is measured.

But what I was really trying to get at was some sound theoretical or mathematical method for determining the number (if such is possible).

Thanks for your reply.

reply to post by chr0naut


To be honest, scientists don't even know much of anything about gravity. It very well may be the electromagnetic force. "Gravity is magnetism"

It took scientists a while to combine electromagnetism and the weak force into the electroweak theory. It is considered that gravity's reach is infinite, as a structure of the universe. Some theories suggest gravity is just a magnetic dipole, where attraction of each atom extends much further than it's repulsion.

Others believe in the hypothetical Higgs-Boson particle

Higgs Boson

It is the hypothesized particle that gives other particles their properties such as mass and spin.

The Higgs boson is the only Standard Model particle that has not been observed in particle physics experiments. It is a consequence of the so-called Higgs mechanism which is the part of the Standard Model that explains how most of the known elementary particles become massive.[2] For example, the Higgs boson would explain the difference between the massless photon, which mediates electromagnetism, and the massive W and Z bosons, which mediate the weak force. If the Higgs boson exists, it is an integral and pervasive component of the material world.

IF it exists.

Wow, 3 posters beat me to the punch...

Let me just state my opinion about gravity. In order to resolve the various paradoxes regarding black holes, combining quantum theory with gravity, etc..., there has come about something called the holographic theory, that states that anything happening within a given volume can be described by information. This information doesn't take up the volume, but rather can be fit onto a surface that bounds that volume. (i.e. for a sphere, the volume inside the sphere could be described by information fit onto the surface of said sphere.) Quantum comes in by defining a smallest possible area for a bit of information. The whole idea comes about by trying to understand black holes, but applying the logic in reverse (avoiding all the conundrums) results in a theory that supposes gravity as simply being an entropic force that tries to compress this data. In this theory, the event horizon of a black hole corresponds to the smallest possible surface on which all the info inside can be stored. So gravity is sort of like a universal data compressor. You're welcome if I blew your mind.

-Balboa

Originally posted by chr0naut
reply to post by rogerstigers

 

Since Spacetime itself can travel much faster the light, then we currently have no way of measuring the actual speed.

I am trying to concieve how spacetime travels. I would have thought spacetime is the substrate against which travel is measured.

The speed of light in vacuum can be thought of as what connects space and time. The whole of space-time consists of everything that has, is and will be, and doesn't have an associated speed.

-Balboa

I think this is a really good question and something I have pondered a bit recently so I'll throw my thoughts out there. I'm not a scientist and I don't know the math so I can only conjecture about what what I've been told is true from sources I consider credible and my own theories.

I've heard that when scientist do calculations to determine the path of travel for bodies in space, gravity is treated as acting instantaneously and that if it is limited to the speed of light the calculations do not come out correctly. Also I've wondered since a black hole can pull in photons and not let them escape then it seems the force of gravity must be travelling faster than the photons.

Brilliant answers so far but I feel that science hasn't quite gotten it yet.

I understand how (on a quantum scale) a shared Higgs between two particles in motion can alter their angular momentum causing them to change direction towards each other (and that if we are moving in the same relative frame we don't see their movement through space, only their apparent attraction to each other).

... and I can see how (on the macro scale) the the warping of spacetime changes the path between masses and therefore brings them together.

... but both of these models ascribe the same action to vastly different mechanisms (in my view) and neither works at the other scale.

So I still have the feeling that we don't have an answer just yet.

reply to post by goatfish


I think your post is right on the money! That is what I am trying to get at.

thanks.

There is a field of science called electrogravitics, sounds like Einstein did finish his unified theory but the military stamped 'Top Secret' on it. I have seen a few studies where very high voltages do affect gravity. It kind of puts it on the speed of light sort of range, but being a different incarnation of force may have some variation in its propagation. When you do drop a ball, it does take a little bit to overcome the stationary inertia before it starts to fall. Need some pretty sensitive equipment to determine how long it takes for the first little microscopic movement to occur.

reply to post by kwakakev


Yeah, that would also relate to what Podkletnov/TTBrown/Ning Li/Tajmar & etc have theorised but it seems that either the reasearch has stalled or that for some reason, people with better equipment cannot replicate the results.

I hope & wish that a loophole in current theory is found soon.

Originally posted by chr0naut
I understand how (on a quantum scale) a shared Higgs between two particles in motion can alter their angular momentum causing them to change direction towards each other (and that if we are moving in the same relative frame we don't see their movement through space, only their apparent attraction to each other).

... and I can see how (on the macro scale) the the warping of spacetime changes the path between masses and therefore brings them together.

... but both of these models ascribe the same action to vastly different mechanisms (in my view) and neither works at the other scale.

So I still have the feeling that we don't have an answer just yet.

This is very true, there isn't yet a definite answer. Higgs bosons are still theoretical, and come about due to the so-called Higgs mechanism. Obviously due to Higgs, these bosons come into the quantum field theory in a similar way to antiparticles. Antiparticles were originally thought to be negative energy particles traveling backwards through time, which in fact is an equivalent description to antiparticles with positive energy traveling in the normal way through time. The latter makes more sense, and so is the accepted description. The Higgs mechanism does a similar thing by taking unphysical results from quantum field theory and realizing that they are equivalent to the description of a scalar boson. The problem is we've never detected a scalar boson, and there's a decent likelihood that there shouldn't be ANY scalar bosons (we've never detected one). Luckily, we may not need a quantum description of gravity. The reason why not is due to the weakness of gravity. I'd like to think that gravity is not fundamental.

reply to post by chr0naut

Basically, we know the speed of light, but gravitation is not electromagnetic.

Some would disagree...

BTW, welcome to ATS and I'm sure a friendly Mod will be along shortly to tell you that starting a thread before you have 20* posts is a no no..

One thing I have noticed is that on space missions, astronauts in zero G are able to propel themselves forward by wriggling their bodies in a screw like fashion.

At the speeds that they are able to move, air currents could not be what they are pushing against so how does that work?

reply to post by backinblack


Oops, I'm sorry if I don't have enough posts.

My profile says that I have 88 posts at present?

Just realised that you meant 20 star posts. I'll try & fix that soon.

That's only half of the "equation:" the other "parts" are electromagnetic flow or fields and there is one other: "the EM connection" which binds all things instantaneously. This is "quanta" in nature; it's the point between a singularity. I should say the "point of" but this implies there lies something further, but can be an inverse of "sorts," that can be visualized as a "bouncing" ball between two states much like when a black hole feeds and stops feeding, hence the bouncing ball.

Just relaying a "hunch" based-on a loose-association of vague theoretical recollections. Please correct if possible.

reply to post by chr0naut


That's fascinating and not well-known information. Also confirms the "wave or particle" effect of a photon of light moving in a "cork-screw" fashion, much like the orbit of the moon about earth makes the same pattern if you are viewing the moon and earth's orbit looking downward as a disc. What struck me as odd, is that the moon never truly orbits the Earth, and why we only see one side at all times. It never revolves around the Earth, hence only one side is able to be seen. almost like a EKG with one beat per month, but instead of the beat moving in a linear line, perspective shifts and moves as the beat.

Is this non sequitor?