Gravity waves detected for the first time ever

[Q-reeus]

But it is re-radiation in the sense that an interferometer based gravity wave detector depends on the warpage of space to modulate the PHASE of an EM emission from a laser in one arm by means of shortening or lengthening it, but NOT to affect the phase of another beam at right angles to it, or to affect its relative phase to a lesser extent.

Cut out the first eight words and that passage makes sense. As to whether nature agrees with that standard expectation of effect of quadrupole mode TT-gauge GW's, many are anxiously awaiting as per OP post. It's clear to me your #27 is not talking about laser interferometer optical frequency fringes re 1/3rd lambda resolution limit, but about the size of a detector (e.g. LIGO arm lengths) relative to GW wavelength.

There is no such limit hinted at for either resonant mass or interferometer detectors. The actual detection limits are owing to various noise sources, and any number of online resources list them together with graphical representations of the 'sweet spots' that minimize the combined noise inputs.
Re-radiation by a massive object e.g. resonant bar would be fantastically feeble relative to an already fantastically feeble incident GW and detection of such by any principle whatsoever is utterly out of the question.** Your persistent claim of 1/3rd lambda resolution limit is a direct appeal to the classical diffraction limit of optics - and consequently implies such detection of reflected (re-radiated) radiation.
**[for sake of completeness will mention one maverick researcher who evidently still holds out hope of amplifying GW's by some fantastic factor of ~ 10^42 via 'quantum rigidity'. I linked to him recently in another thread here:
http://www.sciforums.com/threads/proving-gravity-waves.153178/page-2#post-3353626
A check of his arXiv entries: http://arxiv.org/find/gr-qc/1/au:+Chiao_R/0/1/0/all/0/1
speaks of someone obsessed with radical ideas.]
As far as engaging with your theory side of things re nature of space/space-time - sorry but - pass!

 

[Schmelzer]

If gravity waves don't show up, there is a problem with one of our most advanced and best supported theories, which would be devastating.

Theoretical physicists in general would be happy if there would be serious problems beyond those already known for GR - it would mean, they have something interesting to do, namely to search for a better theory of gravity.

In this particular case, I would be unhappy, because my own theory of gravity predicts also gravitational waves, there is no difference to GR in this question.

 

[danshawen]

Light travel time over space is intended to synchronize clocks, not define space. Space is defined according to Newtonian mechanics.

Quantum entanglement happens faster than bulk matter or energy can propagate in this universe, so this is by far the better way to synchronize clocks. Quantum entanglement is what chiefly demonstrates that space is an illusion, no more substantial then a wavelength of EM that is Doppler shifted in the absence of a knowledge of its frame of reference at rest. This allows for a more rigorous definition of simultaneity the likes of which Minkowski never bothered to dream.

ABSOLUTE SPACE AND ABSOLUTE TIME are defined by Newtonian mechanics, both dead since 1905. If you were an actual physicist, you would know this.

The only absolute space in this relativistic universe is at the dead geometric centers of the fundamental bound particles of energy we refer to as matter. NOT between them. NOT in crystalline lattices made up of them. NOT in the empty space, if any, between an electron cloud of an atom and its nucleus. Not in the empty space between orbiting planets , their moons, or the Sun. Not in the space between our solar system and the center of the Milky Way. Not in the vast interstellar distances between one galaxy and the next. The lengths of all of these spaces is identically ZERO relative to the appropriate relativistic inertial reference frames. We only know that other stars and galaxies exist and are red shifted by virtue of whatever set them in motion aeons ago. Eliminate all of those relative to an observer at rest where you are now and tell me you can make any real sense of any other other object you may see moving relative to you. Are you moving, or is it? It doesn't help to know what its momentum relative to you is. You will have exactly no idea how long or how short, or even how far away it is until or unless it collides with you and your relative motions are combined in the same FoR Just like Doppler shifts actually work. They only register a change in frequency or energy when a source of photons moves relative to wherever you are.

The only absolute time in this relativistic universe is the instant of "NOW" of quantum entanglement. Like the discussion of absolute space in the preceding paragraph, all of those distances mean absolutely nothing in terms of when an entangled particle flips. Its entangled partner will flip THE VERY INSTANT this occurs, and it will happen whether it is part of the same atom, or the entangled partner has propagated to a distance that is the same as the distance measure of the known universe. Entanglement state changes happen much faster than bulk matter or energy can propagate. But even if every clock in every location in the universe were synchronized in a single instant, in the very next instant they would be unsynchronized. The proximity of energy to other energy, bound or unbound causes time to dilate. If you needed to draw a picture of how time is dilated everywhere, that picture would not resemble anything like a smooth curvature anywhere other than in proximity to a gravitational field either. That's because time, time dilation and entanglement is something associated with processes that occur mush faster than matter or energy propagates.

And the model of the spherical coordinate system with light travel time as its ONLY physical dimension is based on a realization of the above realities.

 

[PhysBang]

Quantum entanglement happens faster than bulk matter or energy can propagate in this universe, so this is by far the better way to synchronize clocks.

Except that, by the rules of quantum mechanics, entanglement cannot be used to synchronize clocks!

Why do you ignore the fundamentals of quantum mechanics every time you bring it up?

Why don't you just admit to everyone that your vague replacement for Special Relativity is based on a vague replacement of quantum mechanics?

The only absolute time in this relativistic universe is the instant of "NOW" of quantum entanglement. Like the discussion of absolute space in the preceding paragraph, all of those distances mean absolutely nothing in terms of when an entangled particle flips. Its entangled partner will flip THE VERY INSTANT this occurs, and it will happen whether it is part of the same atom, or the entangled partner has propagated to a distance that is the same as the distance measure of the known universe.

Except that "THE VERY INSTANT" is still relative to coordinate system chosen, since quantum mechanics is consistent with SR. Many cranks miss this because it doesn't fit with their aesthetics.

 

[danshawen]

Cut out the first eight words and that passage makes sense. As to whether nature agrees with that standard expectation of effect of quadrupole mode TT-gauge GW's, many are anxiously awaiting as per OP post. It's clear to me your #27 is not talking about laser interferometer optical frequency fringes re 1/3rd lambda resolution limit, but about the size of a detector (e.g. LIGO arm lengths) relative to GW wavelength.

There is no such limit hinted at for either resonant mass or interferometer detectors. The actual detection limits are owing to various noise sources, and any number of online resources list them together with graphical representations of the 'sweet spots' that minimize the combined noise inputs.
Re-radiation by a massive object e.g. resonant bar would be fantastically feeble relative to an already fantastically feeble incident GW and detection of such by any principle whatsoever is utterly out of the question.** Your persistent claim of 1/3rd lambda resolution limit is a direct appeal to the classical diffraction limit of optics - and consequently implies such detection of reflected (re-radiated) radiation.
**[for sake of completeness will mention one maverick researcher who evidently still holds out hope of amplifying GW's by some fantastic factor of ~ 10^42 via 'quantum rigidity'. I linked to him recently in another thread here:
http://www.sciforums.com/threads/proving-gravity-waves.153178/page-2#post-3353626
A check of his arXiv entries: http://arxiv.org/find/gr-qc/1/au: Chiao_R/0/1/0/all/0/1
speaks of someone obsessed with radical ideas.]
As far as engaging with your theory side of things re nature of space/space-time - sorry but - pass!

A laser beam of the longest possible coherence lengths and times will not be sufficient to construct an optical interferometer with a baseline even one light year distant. It might be possible to do one using microwaves, but the number of phase locked repeaters would also make the technology prohibitively costly, particularly in terms of what such an apparatus is likely to allow us to do just in terms of basic physics.

So, let me put this another way. Let's suppose I am completely wrong and the local interferometer somehow manages to detect a gravity wave from somewhere.

1) Where exactly did it originate or how would you even go about determining this?
2) Great. You detected one. Now, what? You build a bigger or more sensitive one to detect more? To what ultimate end, exactly? How does this advance physics or astronomy? Will you be able to use one to predict Earthquakes, tides, near Earth orbit asteroids? What?

You realize, this is, or should be, an even harder sell than building and operating the LHC.

 

[danshawen]

Except that, by the rules of quantum mechanics, entanglement cannot be used to synchronize clocks!

Why do you ignore the fundamentals of quantum mechanics every time you bring it up?

Why don't you just admit to everyone that your vague replacement for Special Relativity is based on a vague replacement of quantum mechanics?


Except that "THE VERY INSTANT" is still relative to coordinate system chosen, since quantum mechanics is consistent with SR. Many cranks miss this because it doesn't fit with their aesthetics.

The more you respond, the more it appears I am conversing with someone who knows almost no physics.

Relativity IS NOT completely consistent with the Standard Model of particle physics in any part other than the part that is the same as Maxwell's equations for EM. Big deal.

 

[PhysBang]

The more you respond, the more it appears I am conversing with someone who knows almost no physics.

Relativity IS NOT completely consistent with the Standard Model of particle physics in any part other than the part that is the same as Maxwell's equations for EM. Big deal.

People often have trouble reconciling General Relativity with the Standard Model, but quantum mechanics is entirely consistent with Special Relativity. You are projecting your ignorance on others.

 

[danshawen]

People often have trouble reconciling General Relativity with the Standard Model, but quantum mechanics is entirely consistent with Special Relativity. You are projecting your ignorance on others.

And when you persist in Ad Hominiem attacks, what exactly is it you believe you are doing?

 

[PhysBang]

And when you persist in Ad Hominiem attacks, what exactly is it you believe you are doing?

I just point out that you engage in crank behaviors, like avoiding that you have made a gross error in understanding the science to claim that you have been personally wronged.

Will you abandon this fantasy that one can use entanglement to synchronize clocks?

 

[danshawen]

I just point out that you engage in crank behaviors, like avoiding that you have made a gross error in understanding the science to claim that you have been personally wronged.

Will you abandon this fantasy that one can use entanglement to synchronize clocks?

No, I will not. If the entanglement velocity can be clocked (and it ALREADY HAS), then evidently it can be used for clock synchronization, subject only to uncertainty principle limits.

It is fine to accept or reject a proposition based on its respective merits or a lack thereof. It is a fallacy to accept or reject it based on whomever it is who proposed it. This is also known as the GOP presidential debate official fallacy.

We can agree to disagree.

 

[Schmelzer]

People often have trouble reconciling General Relativity with the Standard Model, but quantum mechanics is entirely consistent with Special Relativity.

Only if one has very weak ideas about consistency. Any realistic (in the sense of fulfilling the EPR criterion of reality) as well as every causal (in the sense of fulfilling Reichenbach's principle of common cause) interpretation of QT needs a preferred frame. This preferred frame can be, of course, hidden, but it has to exist (if some reality exists) and defines the direction of causal influences.

If this is sufficient for being compatible with SR, fine. This would be, essentially, the Lorentz ether.

 

[PhysBang]

No, I will not. If the entanglement velocity can be clocked (and it ALREADY HAS), then evidently it can be used for clock synchronization, subject only to uncertainty principle limits.

You need to go and read those papers about the speed of entanglement again.

It's sad that you are so angry about this issue but not passionate about it. You really don't care about being right, only about tearing anything down that doesn't fit with what you have decided about science.

It is fine to accept or reject a proposition based on its respective merits or a lack thereof. It is a fallacy to accept or reject it based on whomever it is who proposed it. This is also known as the GOP presidential debate official fallacy.

I don't reject things because you propose them, I reject the things you propose that are nonsense. I point out that you are engaging in poor behavior in the hopes that you might change.

 

[danshawen]

I reject the things you propose that are nonsense.

What a coincidence. That's exactly the process I am applying to a select subset of the things I was taught.

Except that I have explained why it is I think they are nonsense, and what it is they conflict with, instead of appealing to an authority. A necessary expedient for something that cannot be proven one way or another, unfortunately. Obviously, I can't "prove" that the geometry I am proposing makes more sense then others, and the fact that it is simpler is certainly not a valid argument either. But the fact that their geometry actually explains much less speaks volumes.

If you can't even tell me whether Lorentz contraction of lengths happen from the leading, trailing edges, or the centers of relativistic meter sticks, and if you can't synchronize clocks any closer than the equivalent light travel time and/or the uncertainty principle limits, then don't tell me there is an absolute origin of a Lorentz-Euclidean coordinate system that can be agreed upon in two frames of reference in relative linear motion with respect to each other. Your geometry is flawed, to say the least.

The omission of an equivalent geometry for rotational inertia likewise speaks volumes.

Pauli must have really, really had it tough to sell his idea of entangled electrons in atomic shells. Good thing there are hyperfine spectroscopic energy level changes to support some of those.

 

[PhysBang]

What a coincidence. That's exactly the process I am applying to a select subset of the things I was taught.

But it's not things that you were taught: you consistently get these things wrong. You rail against things that you half-remember or that you imagined.

Except that I have explained why it is I think they are nonsense, and what it is they conflict with, instead of appealing to an authority.

You don't appeal to anything. For example, you simply claim that one can use entanglement to synchronize clocks, despite everything about quantum mechanics that says that's impossible. You mention some tests that were done about the "speed of entanglement", but you don't cite them.

Since none of us here are doing primary research, everything in our discussion will be some sort of appeal to authority. You just would rather we don't actually listen to what the authorities really say.

A necessary expedient for something that cannot be proven one way or another, unfortunately. Obviously, I can't "prove" that the geometry I am proposing makes more sense then others,

Actually, you can. You can also prove that your geometry can actually be used, period. So far, your confusing description doesn't allow anyone to figure out how to describe anything.

I'm not sure what you imagine geometry is for. I'm not sure what you think physics is for, either.

If you can't even tell me whether Lorentz contraction of lengths happen from the leading, trailing edges, or the centers of relativistic meter sticks,

See the excellent post that James R wrote. Or any relativity textbook.

and if you can't synchronize clocks any closer than the equivalent light travel time and/or the uncertainty principle limits,

It's not clear what you mean by this.

then don't tell me there is an absolute origin of a Lorentz-Euclidean coordinate system that can be agreed upon in two frames of reference in relative linear motion with respect to each other.

Nobody said that there is an absolute origin. Everybody defending relativity against your bizarre charges has said that the origin is entirely arbitrary.

You even half-remember or fantasize about what people write here.

 

[danshawen]

I have said gravity waves win never be detected locally by means of local interferometry, and have given two arguments as to why I think not. Others have made no prediction, or said that they hope for detection.

Did you express an opinion? Can you not express an opinion because of a binding non disclosure agreement in connection with LIGO? I won't press you for an answer if you cannot, but I don't believe you have bothered to give us one.

 

[danshawen]

See the excellent post that James R wrote. Or any relativity textbook.

JamesR didn't answer the question either (does contraction occur from the leading, trailing edges, or the center?) Other than that, it was an excellent post, yes.

Neither coordinate systems nor their origins are "arbitrary". When someone hands you you a meter stick and asks you to measure something with it, you will need to know where to align the end ("origin") of the meter stick. If you do not, what sort of measurement is that? Right. "Arbitrary." You are answering like someone who has never even applied geometry.

Where do you think relativity's "gamma" factor (used for both length contraction and time dilation) comes from? A lot of x-x', t-t', and some calculus; that's where. They don't just drop from the sky. You use applied relativistic (not Galilean) geometry , origins and coordinate systems to get there.

But there is no way to get an x or an x' coordinate that does not depend on light travel time itself. Even when you line up the end of a meter stick with something you are measuring, you depend on VIEWING the end of the meter stick (photons entering the retina of your eye) in the same instant that it coincides with whatever it is you are trying to measure. And that is only for a static measurement.

A 4D interval is not always an invariant for entangled events, but the speed of light ALWAYS is. Deal with it.

 

[PhysBang]

JamesR didn't answer the question either (does contraction occur from the leading, trailing edges, or the center?)

You need to read that post again, since he explicitly answered it.

The short answer really should be: if you think that it happens anywhere specific, you really haven't finished reading the textbook.

Your hatred of this subject makes you fail to pay attention when the answers to your pseudo-questions are right in front of you.

Neither coordinate systems nor their origins are "arbitrary".

Bzzt. Wrong answer. Thanks for playing.

When someone hands you you a meter stick and asks you to measure something with it, you will need to know where to align the end ("origin") of the meter stick. If you do not, what sort of measurement is that? Right. "Arbitrary." You are answering like someone who has never even applied geometry.

And you are giving an example like someone who has never held a meter stick. It's entirely possible to use it to measure distances starting from any point on the stick. Pick one up and give it a try.

Where do you think relativity's "gamma" factor (used for both length contraction and time dilation) comes from? A lot of x-x', t-t', and some calculus; that's where. They don't just drop from the sky. You use applied relativistic (not Galilean) geometry , origins and coordinate systems to get there.

Yes, arbitrary coordinate systems in which Newtonian mechanics holds to a good approximation. (See http://www.fourmilab.ch/etexts/einstein/specrel/www/ )

But there is no way to get an x or an x' coordinate that does not depend on light travel time itself.

Yes, there is. Find a meter stick.

Even when you line up the end of a meter stick with something you are measuring, you depend on VIEWING the end of the meter stick (photons entering the retina of your eye) in the same instant that it coincides with whatever it is you are trying to measure. And that is only for a static measurement.

Now you are half right. You are beginning to discuss the use of time in measuring spatial distances. However, you are seemingly saying that blind people cannot measure distances. This is mistaken.

A 4D interval is not always an invariant for entangled events,

Events are not entangled. You keep saying this nonsense, but your repetition does not make it true.

And the 4D SR interval between events is always an invariant, even if the events are the locations of particles or physical systems that are entangled.

but the speed of light ALWAYS is. Deal with it.

I can deal with it. But I suspect that you are too angry to begin to deal with it.

 

[danshawen]

You need to read that post again, since he explicitly answered it.

The short answer really should be: if you think that it happens anywhere specific, you really haven't finished reading the textbook.

Your hatred of this subject makes you fail to pay attention when the answers to your pseudo-questions are right in front of you.

Bzzt. Wrong answer. Thanks for playing.


And you are giving an example like someone who has never held a meter stick. It's entirely possible to use it to measure distances starting from any point on the stick. Pick one up and give it a try.


Yes, arbitrary coordinate systems in which Newtonian mechanics holds to a good approximation. (See http://www.fourmilab.ch/etexts/einstein/specrel/www/ )


Yes, there is. Find a meter stick.


Now you are half right. You are beginning to discuss the use of time in measuring spatial distances. However, you are seemingly saying that blind people cannot measure distances. This is mistaken.


Events are not entangled. You keep saying this nonsense, but your repetition does not make it true.

And the 4D SR interval between events is always an invariant, even if the events are the locations of particles or physical systems that are entangled.

I can deal with it. But I suspect that you are too angry to begin to deal with it.

Even a blind person using a meter stick has to wait until nerve impulses related to tactile sense propagates to and from their limbs before they can make a measurement. Waves of potassium and sodium ionization in nerve conduction are just a whole lot slower than light travel time.

But unless someone can answer the question about which way a length contracts, an exact solution to the question of where the origin of a coordinate system relative to two different FoRs in relative motion actually is located, is as you say, arbitrary, which is to say, useless to any practical means of calculation.

 

[danshawen]

No. Referring someone to a textbook TO DO THE HOMEWORK TO GET THE ANSWER doesn't answer this particular question. It wasn't in my expensive physics textbooks. EITHER of them, as a homework problem with or without a solution, or anything else. If you can find a discussion of this anywhere, please show it to me.

Even though it does not answer my question, I don't blame JamesR for this response. After all, MY FRESHMAN PHYSICS PROFESSOR WOULDN'T ANSWER THE QUESTION EITHER, EVEN FOR HIS "STAR STUDENT", AND HE WAS GETTING PAID HANDSOMELY TO PROVIDE AN ANSWER.

As far as relativity physics as currently or previously taught is concerned, there is no answer to this question. You might as well be asking: "What is the meaning of my insignificant life?"

This is fun. I'm glad you can deal with it and I'm not angry with you at all. The all caps are just because I'm too lazy (and also can't see well enough) to do such things effectively in italics. If I were really angry, I'd probably do all caps and bold and underscore or something.

 

[danshawen]

Here is the "answer" to my question, if you can call it that:

http://physics.stackexchange.com/questions/83520/a-relativistic-meter-stick-and-a-thin-disk

WITHOUT JUSTIFICATION OF ANY KIND, the answer to this question simply assumes that the answer is that the rod and the disk both contract from their geometric centers (and also that the disk ROTATES IN THREE DIMENSIONS, not four).

If I were paying for such help with my physics homework, and they offered this as an answer, this is the point at which I would find a different major worthy of serious attention. This is not a definitive answer. It is a mathematical convention. I do understand the difference.

You are very welcome.