joigus

This is only valid for static solutions!

And it does. Welcome to our world (the real one.) Radiation pressure is proportional to the number of photons per unit time that hit the mirror and the average energy of the photons, which is, \[\hbar\omega\] which is affected by frame-dependence. Inverse time transforms exactly like frequency. In GR is a bit more complicated, but it can be locally understood in terms of inertial frames. So it's not an invariant (or your cryptic "absolute" word.) Radiation pressure is a frame-dependent object as well. I rest my case. This is about the first time that you've asked a question. I think you can learn some relativity in a reasonable time (compared to Eddington's years) today thanks to the fact that you've got lots of material, in the form of online courses. Many people here can help you. There are wonderful free e-books out there. You're not dumb, you're just sticking to your guns to the point of nonsense. You can teach yourself relativity by reading good books and following excellent courses, but you've wandered alone for too long. Neither Einstein nor Eddington were lone wanderers. Every (static) exact solution in GR carries with it what you call an acceleration field. What the meaning of it is is far less clear to me. What's sure is that changing coordinates to locally flat (inertial) takes you to what the free-falling observer sees. But the starting point from the exact solution is far less clear in my opinion. I'm looking forward to what the experts in this community have to say. Mercury's precession is already a solved problem to 43'' of arc per century. Bettering that is a pretty tall order. I would start with vector calculus and a relatively simple model of field theory, like Maxwell's equations. When Einstein postulated his equations, he took Maxwell's as a model.

Missed this. This really says it all. A viewing angel is telling me from nth layer that you're mistaken. Cheers

So you do dimensional analysis... I'm impressed!

Blimey! 7 years! No wonder he's experiencing time dilation. Thanks a lot, Studiot.

Thank you, Markus. Although you've shot too far ahead for him. I can't +1-you because I've run out of points.

'Absorption and instantaneous re-emission' was a colloquial way of saying 'radiation pressure' of the photons on the cavity where you're confining them to make the clock. I said that to have you picture in your mind that the photons are interacting within the clock by means of non-gravitational forces. Then I rephrased it as 'radiation pressure,' just to see whether you understood it better: Then, on your linked Caltech article (https://www.caltech.edu/about/news/caltech-scientists-create-tiny-photon-clock-1029😞 Lo and behold, your Caltech publication confirms my diagnostic. What was I telling you? Radiation pressure. You've missed the point completely. That's what makes your clock be affected by time dilation (never mind it's made of photons.) And I, and everybody here, is tired of repeating to you, but there it goes once more: Time dilation is a frame-dependent effect. As I spent many hours, c. 1990, thinking about toy models for massive elementary particles made up of bouncing photons (massless) and had to rule them out because I wasn't able to postulate the self-interaction, I know what I'm talking about. IOW, I had the same idea (just the non-crazy snippet) than you 30 years ago and it took me less than 24 hours to throw it in the garbage can. I didn't in my wildest dreams try to model gravity with that, though. And please, don't try to smother me with big names like Eddington or Feynman to try and push ahead a crazy idea. We're all grown-ups here, or are we?

I never said that. The bouncing photon clock that you talked about involves photons interacting with matter, which no longer is a photon travelling through the gravitational field. Such system, with two parallel mirrors and a photon bouncing back and forth, doesn't work like you claim it does. If you ever see a radiation pressure fan or radiometer, you will understand what I mean just looking at it. You won't have to think or listen to anybody, or read what they say, which for you is a definite advantage: photons push against a mirror, you see? That's why your idea didn't work. But I'm starting to lose track of what you're saying. You've talked so much nonsense today I can't keep track. Now those are real photons, not the ones that are in your mind. Cheers

Yes, this is Richard Feynman in 1965. Have you heard of entropic gravity? Erik Verlinde deduces Einstein's equations and Newton's laws. And it is by no means sure it is the right theory: https://en.wikipedia.org/wiki/Entropic_gravity#Criticism_and_experimental_tests IOW, people don't buy it just yet. Why should scientists pay more attention to you than to Verlinde, for example? Com'on, don't make a fool of yourself any longer. This is really painful to witness.

rjbeery, I'm giving you some homework: https://www.amazon.com/Introducing-Einsteins-Relativity-Ray-dInverno/dp/0198596863 You don't sound to me like you're completely off your rocker. Maybe you've tried to get into the forest a little too deep, a little too devil-may-care, and without dropping your breadcrumbs on the floor. I don't want to be completely negative. So there you are.

When a particle is massive, wavelength has to do with mass by De Broglie's relation, \[p=mv=\frac{h}{\lambda}\] p is called 'momentum.' m is the particle's mass, v is the particle's velocity, \lambda is the wavelength and h is Planck's constant. For photons though, it's also, \[p=\frac{h}{\lambda}\] But expressing p as mv is no longer valid. So the photon's wavelength has nothing to do with its mass.

1) I do not believe anything, I need, demand AAMOF in this context, logical proof or experimental evidence. You have neither. 2) Clock rate is a relative (frame-dependent) quantity. Plus you only too obviously don't understand special relativity, let alone GR.

Before re-iterating too much, I would suggest you re-read what people are telling you, and then re-think for a change.

OK, but you're drifting away from entropy. I mean, electrons, photons or pi mesons can 'experience' curvature (and there I do accept your term,) but not entropy, as entropy is a property of your level of description. It's to do with lost information, and particles don't lose any information AFAIK. Or the concept of them 'experiencing loss of information' doesn't seem a reasonable physical concept. What entropy growth (or information loss) has to do with is a quite abstract but useful concept that is called 'volume of phase space.' It is a measure of the amount of information that a physical system contains just because of the fact of being in a certain dynamical state. This 'volume of phase space' is neither lost nor gained; it's constant. Just constant. Entropy is the part that is hidden to my description. We could say, \[S=\textrm{constant}\] This is sometimes called 'microscopic entropy' and its conservation is the most fundamental physical principle there is. Now, it just so happens that many things go on without us knowing about it. Only because there is a fiduciary value of a quantity that stays constant and I can associate with the information content of a system, can I speak about loss of information. Otherwise it wouldn't make any sense. I hope that helps to clarify the situation as to the entropy. It's a really confusing concept, and the great mathematician John V Neumann once said that physicists don't know what entropy really is. No longer the situation, I think.

How do you define 'absolute'? For any object moving, you set clocks and systems of laser beams going back and forth to measure positions and time intervals (the latter calculated taking into account how much the signals delay in reaching the observer, it's not 'subjective' time we're talking about; it's not 'when I see the object.') Now, let's call them dt, dx, dy, dz. The so-called proper time of the moving object, in Special Relativity, and with the proper generalization, in General Relativity too, is, \[d\tau^{2}=dt^{2}-dx^{2}-dy^{2}-dz^{2}\] For what observer? For all inertial observers! Now, that's what I would call invariant (I'd never say 'absolute'.) And in order to do that, you need a system of signals, as they're trying to tell you. You need a way to bring it all together, so to speak. For a photon, the proper time is always zero, so photons have no internal clocks. While, seen from the 'outside' in empty space, they always go c.

Sorry, I didn't see the geodesic equation, I didn't see Einstein's equations derived, I didn't see the equivalence principle, I didn't see the Newtonian limit, I didn't see gravitational horizons, FRW or DeSitter universes or any other cosmologies, I didn't see vacuum energy, I didn't see dark matter, or red-shift, I didn't see a thing that even remotely reminded me of gravity, except in the title and Eddington's paper. I suggest you change your mindframe: Try to prove yourself wrong. If you always try to prove yourself right, you're always going to find a way to be right.

I don't know exactly what you mean with 'experience.' Systems of both massive or massless particles contain entropy, a black hole contains entropy of a very different kind, and even for one quantum particle entropy can be defined in terms of its wave function. Entropy, at the most fundamental level, is defined when the distinctions among different dynamical states are lost. Entropy is the opposite of information. The total entropy of the visible universe in cosmology approximately equals the number of photons, about 10^90. A gas of photons contains entropy. So I suppose the answer to both questions is yes. I've just answered the one that Strange passed on, but he was spot on when he said it's about 'systems.'

I was about to tell you about your mistake with the ticking clocks, to do with absorption and re-emission, and elaborating on your messing up red-shift with slowing down. But it would be wasted on you, as there's no one reading at the other end. I close with a quasi self quotation: Gravitational fields do not slow down photons, they just-red shift them and make them bend their trajectories. Read some relativity books. And a literal self-quotation:

I meant, -Today I've learnt about: geons Indebted to MigL

Gravitational fields do not slow down photons, they just-red shift them and make them bend their trajectories. Think again. In no way does that resemble an electron. A bundle of EM field does not have charge, nor does it invert the sign of its probability amplitude under 2pi rotations, which is required. And I've missed the part where you provide a causal mechanism for gravity.

-Today I've learnt about: Einzel lenses and viral load in aerosols. Indebted to: Swansont -Today I've learnt about: colour-entangled W states Indebted to: Studiot -Today I've learnt more details about: quaternary-structure protein dymers and palindromic character of RNA sequences Indebted to: Dagl1 and CharonY -Today I've learnt about: Intricacies related to atmospheric CO_2 absorption by weathering at the Himalayas Indebted to: Area54 and Studiot -Today I've learnt about: phenomenological/heuristic aspects of cosmology in general Indebted to: Mordred -Today I've learnt about: geons Indebted to Strange There's quite a bunch of 'todays' there. And I'm still learning. And counting...

Easy. If what the survey says is actually true --see below: Analogy --not to be taken literally: Go to a prison and ask all convicts for murder crimes whether they're guilty or not. You end up with a list of: 10 % say they did; 65 % say didn't and 25 % don't remember. Conclusion: Only 10 % of convicts for murder crimes actually did commit a crime. Explanation: In the words of Daniel Dennett; American Philosopher and scientist, outstanding at exposing many religious (and other) logical fallacies IMO, "they believe in believing in God." I.e.: They live in a social environment in which it would be far more costly for them to declare themselves atheists than to keep on pretending. Dennett, e.g., takes no prisoners when it comes to theologians. They all fall --willingly or not-- in the use/mention fallacy: "A history of God," "God in our society," etc. Religion is absolutely rife with fallacies, half-truths, and conveniently spun arguments and data. Besides, as iNow says, . Excellent point.

It never crossed my mind. Well, it did, but it was a virtual process.

Forgot to say hello. I'm Joss, I teach Physics, Maths, Chemistry and English @ some academy in Spain. They sometimes make me teach Bio and Spanish, because they somehow assume I must know everything. I'm a theoretical physicist. My alter ego is Sisyphus. PD: I love Yogi Berra quotes

Feynman Lectures on Physics, volume 1, chapter 1, Section 1-3. Atomic Motion. Go to your local library and start reading Feynman now. Then start mimicking Feynman in whatever way you can without giving up your principles, and maybe buy a pair of bongos. Just joking. But the key word in all of this is: Feynman.