MigL

The units of frequency are events per second, where in the case of light the events are wave cycles or peaks, if you will. So light is a clock. And it is affected by time dilation ( gravitational and kinematic ). So if the 'clock that is a light wave changes due to time dilation, its frequency changes. And frequency being intimately associated with its speed, c ( which cannot change ) means that wavelength changes inversely. And that is what we measure, the wavelength shift. We are, in effect, comparing two clocks, the one in our frame ( observer ) with the one of a frame deeper in the gravitational well. And we are doing this simply by comparing the light in two different frames. This effect is not, nor can it be evident, if you consider just one frame. Just think about it, in its own frame everything is as normal. There is no change in its own frame. So yes, the change is frame dependent, or if you will, the observer needs to be in a different frame to measure any comparative time dilation.

Very interesting post ( and subject ), ydoaPs. It seems like Loop Quantum Gravity, as pushed by your 'man-crush' ( Rovelli ), has built-in answers to a lot of the problems. The fact that, in the classical limit, it seems to reduce to Einstein-Cartan theory and not GR does however present a problem. It seems that the torsion tensor being non-zero in ECT, causes the Dirac equation to become non-linear, and causes problems with quantization. But I'm very much out of my depth here. Maybe one of the other members with a deeper understanding of GR and ECT can break it down for us

As if the American elections aren't enough of a circus, now you want call -in voting like Dancing With The Stars ? And the martial arts are for the televised match; Who needs a debate ! ( personally I think Hillary could kick Donald's ass )

Or, he could just be THAT ignorant and not have a clue what the second amendment states.

Only if you take my last sentence the wrong way, Disarray. If it measures like a 'duck', it is a duck ! If the ruler measures shorter it IS shorter. Your reality is only in your frame. Never mind what other different lengths of rulers are measured in an infinity of other frames. None are favoured, and so all are real IN THEIR OWN FRAMES.

Your opinion is certainly valued here, and you have every right to that opinion. Just like Jimmydasaint had a right to his opinion. But, until backed up with facts ( as Prometheus asked ), that is all they are. You can continue the discussion if you wish, as it has been fairly well behaved so far; I found it interesting ( and may even share some of your ideas ). Or you can take your ball and go home.

It doesn't contract in its own frame, you're right. But it may contract in the frame you measure it from. And it will affect you, in your frame, as contracted. A frame doesn't have to be a light year away. It could be right in front of your nose, but with a relativistic velocity. It is still a different frame, and you will measure contraction of the ruler. Furthermore upon a collision, the ruler will act as if it is shorter. It affects your frame as you measure it, not as in its own frame. So, if it quacks like a duck ( your measurement ), why do you keep insisting its a rabbit ( in its own frame ) ????

Relativity doesn't 'cause' the effects. These effects are just the normal workings of the universe. Relativity EXPLAINS the effects. ( if you understand it correctly- as Strange points out )

My vote still goes to Emmy Noether. Held in high regard by Hilbert, Klein, Einstein and Weyl. Her mathematical work has guided modern physics for the last century. Unfortunately she died young and only became an actual professor when she moved to the US in the 30s.

You might have some difficulty giving H. Clinton a rectal exam. She's a bit of a 'tight-ass'. ( she should have a little more fun, like her husband does )

Would it be fair to say that religion is a reflection of cultural mores at the time of introduction ? And afterwards it acts as a 'brake' to the development of cultural mores ? While Christianity was 'introduced' in the 4th century the last several centuries have seen some developments that try to keep pace with cultural development. The Vatican actually encourages scientific enquiry these days ( unlike Galileo's time ). Islam on the other hand, seems to have almost stopped its development about 10 centuries ago, after a brief period of about three centuries, where it spread its influence and culture across North Africa, Southern Europe to Spain, and as far eastward as the Punjab. I would also assume that the fact that Islam doesn't have one coherent voice ( like the Pope for Christianity ), makes it more susceptible to the whims and personal agendas of the individual imans who 'interpret' the Quran ? One might preach peace, another death and destruction to the West by suicide bombings to gullible followers.

No Mike. The gravitational wave medium cannot be particulate. Even dark matter interacts gravitationally. So how does the gravitational interaction get from one particle to another if there is no medium between the particles of dark matter... Can't you just be happy with space-time geometry as the field, and the medium To Disarray... Even with the equivalence principle the speed of light is invariant. Light is massless and constrained to move at the SoL. However light is a wave, and has a time varying amplitude. As such it can be considered a periodic clock signal ( the spacing between the peaks of the wave ), and yes, we do find a time variance in the signal when comparing signals from different depths in a gravitational well. A signal from deeper in the well will have the time between amplitude pulses stretched, or dilated, compared to a signal coming from higher up in the well. Notice that this is equivalent to a wavelength increase, or red-shift. Reality has nothing to do with dimensions. It is what affects you, i.e. what you measure.

I guess we all struggle trying to put relativity in everyday terms and words. Its really meant to be treated mathematically. But how about this then... Reality is frame dependent. A nerf ball could be nearly stationary to observer A' frame, and when it hits him he won't even feel it. That same nerf ball could be moving at thousands of miles per hour as measured in observer B's frame, and when it strikes him it'll be like a ton of bricks. Same nerf ball, but the way it interacts with each observer's frame is different, but equally valid. Whatever you measure in your frame IS the reality ( distances, times, colors, masses, etc. ) in your frame. Whatever is measured in another frame is the reality in THAT particular frame. ( kind of makes 'reality' subjective, doesn't it )

The EM field he is talking about would be the QED field which gives rise to charged particles and photons, Swansont. This was a 'gimme' to Mike in the hope of stopping this discussion before it went to 10 pages ( now at 35 and rising ). But it doesn't have photons zipping through it Mike, excitations in the field ARE the photons. As for your ideas regarding the medium for gravitational waves being the masses that are scattered throughout the universe, Mike, just like the fibers in the carpet... How does the wave then get from one mass to another ? There has to be a mass in between to wave, doesn't there ? And how does the wave get to the in-between mass? There has to be mass continuously throughout the universe ? See how silly your idea quickly becomes ? But if that thing you don't like, space-time, because it is just abstract geometry; if we allow it to have energy ( virtual particles are borrowed energy ) then it has the equivalent of mass. And we can 'consider' it a continuous mass throughout the universe. Then we do have 'mass-energy' as a 'medium'. Now can we put this to rest ?

Move to Canada. We have the second largest land area in the World, the most fresh water and only 35 mil inhabitants. And we like company.

There is a type of resistance to the rug's wave, but not in the way you're thinking. There is no need for air or any other 'medium' for the rug to be immersed in, so it will work in space as well as on Earth. The 'resistance' is provided by the rug's inertia. In effect, the rug is the medium, and the energy of the wave is transferred to each succeeding point as the wave 'travels'.

You're always too darn reasonable, iNow. You're right, he did 'open the door'. However, if those beliefs help him cope with tragedy, whether they have basis in fact or not, why would we feel the need to challenge them.

I did not say the people who committed 9/11 were insane, although the argument could be made for. I said they were evil., And I also wouldn't say they were particularly religious as they enjoyed porn, prostitutes and booze. And then iNow brings pedophilia into the discussion, while John introduces Satan worshipping cats. Jimmy isn't pushing his religion on anyone. He came on here, but didn't try to convert anyone. His beliefs are simply HIS beliefs, and facts are not the basis for beliefs. He is certainly entitled to them. And if those beliefs help him through a difficult time in his life, so much the better. From reading this thread I get the impression that you guys are trying to convert him.

No, I'm saying those evil people would have used any other means to perpetrate their crimes. even if religion hadn't been available.

You're right John. Next time we see Pakistanis burning American flags and calling the West 'Satan',we should bomb them because they support terrorism. Look, all I'm really saying is, I don't have a problem with religion. It has its purpose, and some people need it. This very need is what makes these people easy targets for unscrupulous others, who use the institution to take advantage of the needy people. Somewhat akin to cancer patients who will grasp at any straw, or unproven treatment, pushed by unscrupulous hucksters, in an effort to survive. I have no need for religion currently. I hope I, nor anyone else ever need it. And I will not deny it to those who are unfortunate enough to need it.

We live in a closed system ( so far ). And closed system populations are self-governing ( by choice or circumstance ). So there will never be OVERpopulation. Oh, and I always thought humans tasted like chicken. Now Phi and Endy tell me it tastes like veal and Stringy says it tastes like mutton. I can't decide whether to try it or not; I like veal but not mutton.

Well Andrew, there's an example in the above post by Tampitump. "thousands of years of...committed by RELIGION" It wasn't the hijackers who committed 9/11, it was Islam. It wasn't Torquemada that brought about the Spanish Inquisition, it was the Catholic church. Why don't we stop blaming the institution, which has the purpose of bringing hope to desperate people, for the acts of a few demented individuals who use that institution to gain power/property ( some popes ), exact revenge on others ( hijackers or inquisitors ) or take advantage of others ( tele-evangelists ).

Open threads and start asking all those questions. Whether answerable or not, we all love a good discussion.

So you're OK with the field being the medium. And immediately you start running off on tangents, bringing dark energy ( ? ) and dark matter particles ( ? ) into the picture. Until you realize you don't have a clear understanding of what a field is. ( a value associated with every point in space or space-time, as the case may be) And so a field isn't 'material' enough for you anymore. You need something you can touch. Something you can see. You have been told why an EM or gravitational wave cannot be a 'waving' of particles, and you won't accept the field waving. What else is there ???

D. Trump is falling fast in the polls. He cannot win. Unfortunately, H. Clinton can lose. Hopefully she, and the rest of the Democrats, don't have anymore 'skeletons in the closet' that'll put heat back on them. ( that's a pretty nasty word to use in a public forum, Phi ) Oh, and I hope J. McCain withdraws his support from D. Trump, as any principled Republican should . I don't think D. Trump's endorsement will help J. McCain with his re-election as their bases are totally different.