WTF is the speed of gravity

[KrazyHorse]

Originally posted by Ethelred


Crank site.

Even though he has a real science education he is still a crank.

Lambert Dolphin is under the delusion that the Earth is only about 6000 years old. So to patch physics he and others sometimes pretend real hard that the speed of light is EXTREMELY variable. Carefully ignoring the fact that it would cause other variable to change so much the Earth would be a molten ball with metalic vapor for an atomosphere due the accelerated decay of radioactive material that he needs to make the Earth look so young.

I didn't even realise he was involved in Creationist gobbledygook. The site was wacko enough on its own merits...

[KrazyHorse]

Originally posted by Phil_de_geezer
I can't for the life of me figure out how they are going to test this.



Surely this measures the strength of the field that the light is passing through?

It does exactly that. However, the strength of the grav. field depends on where the photons from the quasar "see" Jupiter (since, presumably Jupiter is moving relative to the path the photons are taking between quasar and Earth).

[KrazyHorse]

Originally posted by Ned
Interesting article on a number of points.

Point 1. The speed of light relative to a moving observer is not constant. Because matter is a wave, the clocks change to make it appear constant

Bollocks. Your interpretation sucks ass

Point 2. If gravity has a speed, it is much, much greater than the speed of light

Bollocks. We've not had the ability to adequately test the speed till now due to weakness of grav. coupling constant.

Point 3. The postulate than nothing can propagate faster than the speed of light is false.

Bollocks, as it is based on (2)

EDIT: changed (1) to (2)

[KrazyHorse]

Originally posted by Ned


The article states the facts and concludes that they are consistent with Lorentzian Relativity and inconsistent with Special Reltivity.

But these are the conclusions of the author who issues a challenge to the adherents of Special Relativity to provide an explanation.

The universe is consistent with Lorentzian Relativity, not Special Relativity. Special Relativity (Einstein) says than nothing can propagate faster than the speed of light. Lorentzion Relativity does not.

Gravity clearly propagates much faster. It is also possible to travel faster than the speed of light in the Lorentzian universe.

BollocksX10

The author has stated "facts", not facts.

[KrazyHorse]

Originally posted by IoT


That's my understanding. Essentiall momentum has to be conserved and emitting an exchange particle requires an appropriate change in the emitter and ultimately in the absorber too. This is a very simplified view of what happens and its been many years since my undergrad particle physicis courses. You can bet there is a ton of Quantum Mechanics in there somewhere

Arggg. Yup. QFT does away with messy individual virtual particles, from what I understand...

[Ethelred]

Originally posted by Frogger


I didn't even realise he was involved in Creationist gobbledygook. The site was wacko enough on its own merits...

I have known about Lambert for over two years. I have him in my reference section of my favorites. Just in case someone uses him for a source. Some pages are more clearly Creationist than others but all the science on them is based on the idea that the Fundamentalist view of the Universe is the basis or at least the guidline for all knowledge.

While it is possible that the speed of light is not constant there sure is little indication of it for billions of light years out into space. I think maybe a little at the edge of our perception and that is where the idea of an accelerating universe comes from.

[Ned]

Alright, Frogger, Does gravity have abberation or not?

[Ethelred]

Originally posted by Ned


The article states the facts and concludes that they are consistent with Lorentzian Relativity and inconsistent with Special Reltivity.

Are you referring to Slowhand's link to the Lambert Dolphin site? I didn't bothet to look at it. THIS TIME so don't anyone think I am being close minded. I read that nonsense a long time ago.

That site has one idea of what constitutes fact. The Bible and only the Fundamentalist view of the Bible. Any facts that show it wrong are either ignored or subjected to what can at best be called unproven hypothetical manipulation till all sight of reality is either lost or covered over.

There are stars that are billions of light years away. Hmm what to do. OH I HAVE IT. The speed of light has changed. What do mean the evidence doesn't support it. The Bible shows us the universe isn't that old so the speed of light must have changed.

There are way too many products of the U-238 decay sequence. I HAVE A SOLUTION. The rate of decay has changed and U-238 in the past had a decay rate of many orders of magnitude higher than today. Yes thats it.

----

Only Lambert hadn't noticed the last time I looked that his solution would turn the Earth into a VERY hot molten mass even at the surface. Maybe he has patched that up a bit now. Of course that would entail some profound changes in every other element and most likely some changes in probabilistic events that are somewhat inherent in numbers themselves rather than in the specifics of physical constants.

[Caesar the Great]

well i didn't read through all this tread, but i'd like to see if i know anything about this...

if gravity were to travel faster at the speed of light, then the information is being exchanged between two bodies FTL, and that really messes up the theory of relativity right?

so if the sun were to explode, earth's trajectory in space would change either before, after or exactly at the same time we see the explosion...

so theoretically if gravity does "travel" instantaneously, we could be able to use that to send information in 0's and 1's across any distance instantaneously (well there are limitations due to the object used to transmit the 0's and 1's), either the presence of gravity or its absence...

[KrazyHorse]

Ned the Physicisisisisist

I'm going to assume that you are talking about the apparently obvious conclusion that the time of propagation of graivty from source to object would cause an aberration in the force exerted on the object, giving it a transverse acceleration dependent on v/c.

Nothing could be farther from the truth. The author simply "forgot" that Newtonian gravitation is wrong, and hand-inserting a time-delay doesn't make it any more right.

If you know GR, I can show that the leading-order term v/c disappears (and so do all other terms up to (v/c)^5). This makes the grav. radiation effect a quadrupole term. In other words, not very important. This is one of the fundamental topics covered in any intro GR course.

[KrazyHorse]

As a matter of fact, this exact conundrum was "solved" for me in the last week of class for 198-514: GR by Prof. Grant (IIRC)...

[Asher]

[KrazyHorse]

CS wimp.

[Asher]

You know it.

[Dinner]

Originally posted by Sava
On Earth at Sea Level it's 9.8 meters/per second

Actually it is 9.8 meter/per second/per second. However I am still an old fashioned Anglo-Saxon so I prefer 32 feet per second per second.