What is the Velocity?

I questioned that gravitons were faster than light (if they exist).

I am aware that in order to calculate orbits of planets one must assume instantaneous gravitational attraction when using Newton's physics. However, that is a theoretical simplification that is necessary to get good approximations of orbital data.

When more accuracy is needed you must use Special Relativity. Mercury's orbit is a case in point.

When dealing with Einstein's Special Relativity the speed of gravity is C. Those equations work as accurately as we can measure them.

As for what's in the future for extending our understanding of the universe and the laws that govern it, I haven't a guess. The only thing I am sure of for me is that ride will be exciting.

So what you say is.

Light speed is the maximum speed possible and there is no particles that can can travel faster.

The collapsing electromagnetic field is an interesting one but how does that apply to permanent magnets ?

The Earth is a magnet I believe from looking at the Northern Lights effect.

This planet is a really big magnet compared to what you can hold in your hand but why does this magnet still work when it has such a massive opponent.

From what has been described to me (ripples in pond) I think that from the conception of the universe the ripples in the pond have already set up their patterns (big bang and all.) so it follows that it is possible for gravity to exist without mass as in a pond of ripples created by objects bobbing up and down sometimes there is areas of in phase waves and there is no object !!

Is this the answer to black holes ????

Thanks for not mentioning any of my spelling errors and your interesting answers.

It sounds like you are conceiving of waves interference patterns in a pond, but must keep inmind that it may not be true that the wave of gravity can reflect off the edge of the universe and back through the universe. They may be dampened out at the edge of the universe. Plus mass and gravity are linked, so the conversion of mass to energy changes that gravitational effect. Like a pond a bobber floating on the pond when in a static condition generates no waves, the bobber has to change position somehow. Similarly mass has to change to cause changes in gravity that lead to propigating gravity wave fronts. Add the bobber, remove the bobber, move the bobber causes waves, though sometimes so slight they are undetectable.

I thought the universe was expanding and how does a wave bounce off the edge of an expanding universe ?...yeah pond analigy was just a thread from an earlier post.

Mass and gravity maybe linked but can you see what I say...It is about interference patterns.

Okay.....Build a dam in a river...now you can simulate expansion...then throw some stones into the dams pool and you will still get as I describe....but I will admit you will have to fill the pool at the same rate of wave propagation as the stones produce.

However, consider if the waves never reflect to contibute to interference. Plus it would be disisimilar in that you actually only have one wave front propigating not a series of waves. So consider interference from just the leading wave front that never reflects anywhere. In general, you might see interference occur at some points as wave fronts from other sources crossed, but it would either rise or fall and stabilize, not continue to rise and fall. Just superposition of the wave fronts. To set up a actualy recurrent cyclic wave, you would need to have mass changes in a cyclic pattern. To have a static interference pattern, you would need these cyclic waves to occur from multiple sources, or to encounter reflected waves. To detect the effect you would have to be in close enough proximity such that the energy of the waves is not dissipated.

<Light speed is the maximum speed possible and there is no particles that can can travel faster> "All material in nature, the mountains and the streams and the air and we, are made of Light which has been spent, and this crumpled mass called material casts a shadow, and the shadow belongs to Light. Perhaps, our view of travel and particles my be getting in the way of seeing this correctly. As I once read "the hardest thing about learning a new language is knowing an old language". -just a thought

Lets look at this another way, which might clarify the OP question... a little "thought experiment".

Suppose a lump of matter suddenly became "magnetic", is the field immediately present in everywhere in space? If not, how long would it take for it to extend 1 inch? 1 meter? Etc.

The mathematical equation we have for determining magnetic and gravitational strength are steady state equations, not initial or ending. It is much like trying to predict what happened at the origin of the Big Bang -- if you accept the Big Bang theory.

Boy, I sure mangled some spelling and grammar here. My apologies.

;-)

You can easily measure the magnetic field propagation with an electro-magnet. It turns out that speed is C.

Gravity is a much more difficult problem.

magnetics are not steady state equations, otherwise we would not be able to perform calcualtions on power generation from movement in magnetic fields, or moving magnetic fields. The magnetic field strength at the reaction coils must be changing, and non-static to generate power. Also, magnetic field arise and collapse in electric coils affecting phase of potential relative to current. In addition, gravitation is not a static steady state equation, as collapsing stars, condensation or dispersal of mass, and other phenomena where mass densities change can lead to local variations in gravitational fields that must occur subsequent to the mass changes. Example, a body located between the moon and the earth would be subjected to less gravitational force, now if the moon collapsed into the earth relatively suddenly there would be a sudden shift in the gravitational force on that object if it remained the same distance from the center of the earth. Such an effect can occur relatively rapidly when considering supermassive cosmological bodies and great distances to the observer, or even when looking at very small high velocity bodies.

Many experiments have been done to establish the speed of light;
so why not magnetism? Like one can block a flow of light, is it not
possible to block a determined flow of magnetism, then, remove the
block and measure the time it takes to affect a distant object?

Perhaps a needle/electron moved by magnetism over a long distance.

It would be reasonable to assume this is possible to do with great
accuracy say, in a government laboratory? Millions are expended,
(if not wasted) on far more crazier things. And who knows.....

jt.

I'm a very simple person.... and life's too short to argue, friends.

An electromagnet can be gated any way you want.

The speed of propigation of magnetic fields are observable by looking at the collapsing field produced by a coil when the electric current is shut down.

Though a thought does occur, since the magnetism propigates at a speed of c. If you have a rotor with electro magnets rotating at a angular velocity such that the outer edges of the rotor magnets are moving near the speed c, how does this effect the field lines? Hmm, I may have to think about that a little bit.

There may be some empirical evidence in the form of rotating neutron stars, but I have no idea what data is out there or if it is feasible to get such data.

Indeed.

Allow me to express an opinion that is somewhat divergent from the common understanding.

Everybody speaks of gravity as a force, and in the Standard Model it is regarded as one of the four fundamental forces.

However! Comma. According to General Relativity, gravity is not really a force at all, but in fact a distortion in the geometry of space-time, not unlike a dip in an otherwise smooth landscape. What we perceive as the force of gravity is the acceleration imparted upon our butts by the surface of the Earth preventing us from moving in free-fall along our otherwise natural path towards the planet's center of mass.

This... Let us call it a "gravimetric distortion" for lack of a better term, though "mass-warp" also comes to mind... is caused (it is thought) by the interaction of mass with the space-time continuum. This interaction is poorly understood at best, but we do know that all masses cause a gravimetric distortion in the local space-time. And it is quite reasonable to assume that the total mass of the universe also causes a universal gravimetric distortion, which obviously would be experienced by all masses everywhere. And since the total mass of the universe is likely to be a constant, it is unlikely that this total "field" will change significantly.

The point here is that, while gravity is very much like unto a field effect, a gravity wave is not something that moves through space-time, but is in fact a movement of the medium itself. Thus the possibility of propagation velocities far in excess of c.

"Thus the possibility of propagation velocities far in excess of c."

I don't think so. Observations of decaying orbits of binary stars agree with Einstein's theories that the speed of gravity waves is C. They have been able to confirm that to an accuracy of 1%.

But! Until gravity waves are in fact detected and their propagation velocity actually quantified, it remains an open question. Indirect measurements will never satisfy the question.

Remember that the Standard Model is just that, a model. And while it provides a degree of accuracy for most things, the "oddities" are beginning to pile up, just as they did for Newtonian mechanics and for the crystal sphere model before that. Our understanding of the universe is far from complete.

No, I don't think it really isn't that open. What evidence we have supports C as the speed of gravity waves. So far nothing has been found that contradicts the observations to date and the supporting theory Einstein posed.

We may not as of yet measured or observed gravity waves, but we have observed and measured their effects and they agree with predicted theories.

If you evidence to the contrary, you could be a very famous man if you choose to posit a scholarly paper on the subject. ;-)

Why would I want to be famous?

Because we are inundated with a disproportionate number of idiots that have achieved famous status.

I was hoping that adding you might help swing that statistic the other way. ;-)

Hey, I'm just an old-school philosopher that nobody listens to. Though I have to agree with you when it seems that the primary qualifier for celebrity status is being physically attractive. I can remember a time when famous people were scientists, generals, statesmen. *Sigh*

Have you seen all the reality shows about new jersey, obviously physically attractive is not the qualifier.

Thus the possibility of propagation velocities far in excess of c.

Yes that is what I thought.

There is a family of particles (tachyons) who regularly move faster than light- existence not proven.

As per theory of relativity- they have imaginary mass and bringing them down to speed of light will require infinite energy.

Also there are some symmetry experiments (done a few decades back) where a pair of symmetric particles were manipulated and the twin responded immediately - at a distance of quite a few kilometers - and the time corresponded to one much faster than light. And as far as I remember there was no refutations of the experiment.

And as mentioned, there are supposed to be hyperspaces (on theory too, outside the qualm of science fictions) where the effective information exchange would be faster then light. But then those are out of the realm of the normal space-time continuum and there anyway the rules of physics, as we know, would not apply.

The only thing that travels faster than light is bad news.

"There is a family of particles (tachyons) who regularly move faster than light- existence not proven."

That is correct; it is hypothetical.

"As per theory of relativity- they have imaginary mass and bringing them down to speed of light will require infinite energy."

This is concerning the hypothetical particle, the tachyon. All of that is just hypothetical and does not constitute facts.

"Also there are some symmetry experiments (done a few decades back) where a pair of symmetric particles were manipulated and the twin responded immediately -"

I think you are referring to quantum entanglement, which is true. However, it is important to point point out that there is nothing actually moving faster than light. The two entangled photons may react at the same instant, but there is no mass or particle traveling faster than light.

"And as mentioned, there are supposed to be hyperspaces"

There are boundless theories and speculations. If you are claiming that this is evidence for faster than light, the bad news has already preceded you. These claims do not support the argument that any particle is faster than light.

My friend, I refer you to Clarke's Laws, particularly his first which states "When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When the same distinguished but elderly scientist states that something is impossible, he is almost certainly wrong."

The second and third are also worth looking at. "The only way to discover the limits of the possible is to go past them into the impossible." and "Any sufficiently advanced advanced technology is indistinguishable from magic."

The point here is that where older, more highly educated folk will sit there knowing why things cannot be done, younger, less educated types will go out and do the impossible, and then later invent new theories explaining how and why it really was possible after all. And it has happened over and over and over again throughout history.

Operating the scales is a demanding exercise though.

I never said that we should stop postulating new theories.

However, it is important to distinguish between what is known to be true and what is thought to be statistically possible.

While some theorist might make a case that it is statistically possible to step off the ledge of the Grand Canyon and walk to the other side, a wiser man would probably bring a parachute.

Oh, absolutely! But there we are talking about the pragmatic, not the theoretical. We know without doubt that if we step out into open air, we will fall. We know that if we try to breathe water, we will drown.

But, as to the theoretical? It is believed that it is impossible to know both the direction and speed of a particle simultaneously, and based upon currently accepted theory and available technology, so it is. It is believed that it is impossible for a body to exceed c within the space-time continuum, and again, based upon currently accepted theory and available technology, so it is.

But, what about 20, 50, 100 years from now? As our technological capabilities increase, so will our theoretical framework evolve.

Just for example, suppose we build a research institute in flat space, out beyond the orbit of Pluto or even further. Suppose we could build our instruments on a vast scale without having to bow to gravity? What new things might we learn, and how would theory have to change to explain these new facts?

The point is that one day Quantum Mechanics and General and Special Relativity will be just as obsolete as Newtonian Mechanics is for us now. Still useful no doubt, but just not able to account for all of the observational details. I sincerely hope it happens within my lifetime. And I for one will not be one of those who goes to my grave calling the successors to Einstein, Heisenberg and Bohr liars.

So my friend, why not use your education to entertain the unlikely, to look for ways over, under, around or through that which is theoretically impossible today? I'm pretty sure it'd be a lot more fun.

What about those mice they dump in those tanks of highly oxygenated water that survive, though they have to learn they can breathe the water.

Hold on is this implying our butts are causing a "gravimetric distortion".

Yes. All masses, however large or small, create a gravimetric distortion in local space-time. However, the gravimetric distortion caused by an individual human is fairly insignificant, and really part of the total planetary "field".

It is not yet certain that gravity waves exist. Asking for a speed based on the assumptions that it is both a particle and that it exists is asking for an answer that is not much more than a guess.

Here is a link to a group that is looking for a gravity wave.

www.aigo.org.au .

Good luck