You appear to be advocating an Against The Mainstream position, is that correct?

I was just listening again to "Questions" #5 episode, and Pamela herself stated that photons experience NO time. - even though they are moving.

If it is against the mainstream then we'll have to ban Fraser and Pamela.

I was referring to RussT's position--I think he'd disagree with Pamela there. But it seems to go beyond that. I'm not sure.

All good with me as long as I learn something.

Which Grey responded to with a BIG "IF"...the No Time part


[then time would stand still", but that's a big "if"]

I agree, that's the way I understand it. Perhaps Richard could comment on this.

Thanks for the reference on rotation.

I'd disagree, and simply state that the question of how much time passes in the "rest frame of the photon" is not a meaningful one within relativity. In any valid relativistic reference frame, light moves at c, so there's no such thing as the rest frame of a photon. Now, as I said, one can bend relativity a bit, and try to use it to answer the question, "well, what if it were a valid reference frame, how much time would pass?" And it's true that a certain reading of the equations would tell you that no time had passed. But you'd also find that some of the relativistic equations would now include division by zero, so that should be a big clue that you shouldn't take your results too seriously. It's certainly true that there's no way to measure how much time elapses between emission and absorption for a photon, but that's at least as much because there's no way for a clock of any sort to travel along with a photon as because "no time passes".

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Conserve energy. Commute with the Hamiltonian.

Tensor's pretty bright. I'd assume that he's aware that it's not really possible to accelerate instantaneously to the speed of light. But his statement gets most of the idea across. A more precise wording might be that if you travel from here to Alpha Centauri, moving at arbitrarily close to the speed of light, the trip will take roughly four years for outside observers, but will be arbitrarily short for the person travelling. Depending on how fast you go, the trip could take a year as measured by the traveller, or a day, or a second, or a nanosecond. Essentially no time as measured by an outside observer, if the traveller is moving quickly enough. And it still scales. If you're travelling fast enough that time dilation means you measure a nanosecond to go four light years, then it will take you a whole second to travel four billion light years.

As always, don't take a casual statement attempting to explain the general idea of a theory to someone as the theory itself. If you want to know how differently moving observers will measure time according to special relativity, you need to look at the math of special relativity. And if you want to address problems that you think exist within special relativity, you definitely need to be looking at the math itself.

Well, I'm not "ignoring" some blatant contradiction inherent in special relativity. I'm being aware that casual statements about complex theories may sometimes lack mathematical rigor in their effort to explain those complex theories to people who may not have the background needed for a fully rigorous explanation.

Nope. Light travels at the same speed in all reference frames, and that speed is not zero. That's one of the founding postulates of special relativity.

Well, it's true that Einstein started from some simple thought experiments about how light behaves (though you won't find him using any examples of an observer moving at the speed of light), mostly to try to figure out a way to get electrodynamics and mechanics to work according to the same set of rules. And of course what's really important is not that the resulting theory is mathematically consistent (which it is), it's that it is also consistent with all the experiments designed to test it since then.

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Conserve energy. Commute with the Hamiltonian.

I've always been curious: we know photons have the characteristics of waves and of particles, so does a photon accelerate too? I assume not, but why not? Is it because a photon has no mass?

Isn't it the case that nothing with mass can travel at light speed, including any observer we could conceive of? Except in Star Trek of course. Does that make some of these thought experiments moot (regarding time stopping at 'c') or have I missed something important?

I've heard it said that were it not for relativity and the speed limit 'c' the entire history of the universe would play out instantaneously--how does that work?

Hope these aren't dumb questions!

Richard is quite aware of this (if I remember our posts to each other correctly).

Not a problem. For a better reference, the explanation is on page 92 and a pictoral representation is on page 93. This is in the second edition.

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Some try to tell me, thoughts they cannot defend,... - Moody Blues.

I'm gonna hold you to that.

That would be a good assumption.

That was the main idea. If you go back to the post that RussT took that statement out of, you will notice that it was an answer to someone who, I thought, would understand a simpler reply much better.

Your explanation is certainly more correct.


This has been, from my point of view, a problem with RussT's ideas. He's very good at taking quotes from different sources to support his ideas, but he seems to be very weak at actually understanding the math behind those quotes. As a result, to those who understand the math, his ideas seem rather quixotic.

I have, what I think, is a really good example of this concerning Mercury's anomalous precession. While I realize that it is due to the non-linearity of the GR equations, expressed, in the math, as a second order effect of the power expansion series, I like to explain it as the difference between Newtonian Gravity (where mass creates gravity) and GR (where energy is the cause of gravity). One can point out that the energy of the Sun's gravitational field adds to the gravity caused by the Sun. This extra bit of energy causes the extra tug on Mercury, causing the precession. While this explanation is obviously not complete (for one, it ignores the elliptical component of Mercury's orbit), it illustrates some of the differences of the two theories and the non-linearity of the GR equations, for people who have no idea what a power expansion is.

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Some try to tell me, thoughts they cannot defend,... - Moody Blues.

See, you are already using semantics here

Photons/Light accelerates instantaneously to "c". (which by the way is impossible for electrons to magically accomplish!)

Sure it still scales...it is all robustly consistent mathematically. Infact, it is absolutely 'Crap your Pants' perfect, as Publius has been know to quip.

However, it 'assumes' that the current defining of light/photons as having no 'rest frame' and experiencing no time, is correct, and that it is an invalid reference frame.


I 100% agree that light/photons travel at a constant "c", In Vacua/Einstein 'empty universe', in all reference frames. However, you switched to 'light', where I said each individual photon.

Each individual photon (wave) IS just sitting still, at 0 velocity, in/on its Point (Particle), which is carrying it at "c". BUT I don't even need to 'prove' that, to show what is really happening here. Also, even if you assume that the photon is really sitting in/on the 'particle', if you defined the particle the same way as you currently define light in its own frame, then the 'particle' could travelto infinity, instantly in its own frame, and that is still Impossible.

When you get to the very limit of the extremes (ie; Time 'frozen' at the event horizons) is where, when it it is understood correctly (And YES, I do understand!!! Playing the "MATH CARD" will not work anymore, besides, it is Ad Hom to attack, what you or Tensor 'assume' is 'my understanding', with it!!), you can flesh out 'what is really happening'.

SO, when the end result of assigning simultaneity to all photons in their light path, in lights reference frame, and 0 time that a photon experiences, in its own frame, results in photons/light being able to travel to infinity, instantly, in its own frame, YA gotta know that that is Impossible.

And then what happens...you/they just say that it is an INVALID reference frame, BUT YA want to keep all the dilation and contraction...and yes, when you do that, it all scales purr-fectly

SO, what happened, for this to become SOOOO acceptable? That light could travel clear across the universe instantaneously, in its own frame, and Time could 'freeze'? (btw, light/photons do freeze time in a way...when they hit the lens of any of our cameras/telescopes).

That darned 'Spaceship' and those thought experiments, and what would a stationary frame and a moving frame see at relavistic speeds...IT is ALL SCI-FI, and Einsteins SR convinced mainstream (Or I guess it would be more correct to say what is now mainstream), that you/they were seeing what is "REAL" from a 0 velocity position when you hold something stationary in the same reference frame.

SO, sure, if you were sitting on the single photon, traveling at "c", you could not measure your speed, so you have to measure it from another frame to see the reality of it traveling at "c". Just like if you were sitting on the bullet, you could not measure reality from that frame, sitting on the bullet at 0 velocity in your own frame.

We always transfer to another frame to see the reality when we are at 0 velocity in our frame, just as I am sitting here at 0 velocity in my chair, time is ticking away 1 second at a time.

So all the experiments, like Pound/Rebka, that require the 'stationary', are not seeing the reality...you have to switch to the 'other frame' to see the reality...assigning gravitational redshift to the gamma rays in that experiment looks correct, BUT it is the earths rotation that is really causing those rays appear to be sped up closer to a gravitational source. Time automatically goes slower at altitude, and faster toward the center of the earth because of the earths rotation.

And this is what I meant when I finally realized what Ken G was actually saying here...

Now, here is what I will admit...I am not sure how to solve this.
ETA; I meant what someone is going to need to do mathematically. I know how to solve the Time dilemma

We know that Light travels at "c" in Vacua, and that all reference frames see it as so, unless it is curved by a massive object, BUT do we just have to accept that we have to 'figure out' what is happening at the Event Horizon, or whatever frame we are looking for 'what is happening there', OR is there a way to switch the maths around so it will show correctly, that Time is just flowing at the event horizon as the free faller see it.

Hmmmmmm...

Does anyone else see the dichotomy in these two statements? I could give you a hint, but then, since you understand the math all so well, I guess we'll just have to wait until you find it.

I'm not assuming anything. You have made statements to the fact that you don't understand the math and have demonstrated, that you don't understand, in the comments above and in other posts. As to whether or not it is an ad hom, your understanding or lack of understanding is directly related to your claims. You don't show, and have claimed you don't know, the math. This makes your claims rather shaky. As some of your comments directly contradict the actual math.

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Some try to tell me, thoughts they cannot defend,... - Moody Blues.

I would disagree. Photons are created already moving at the speed of light. They don't get created first, and then accelerate. That answers Steve Limpus's question about photon acceleration as well. Photons don't accelerate, they are always moving at light speed from the moment they are created to the moment they are absorbed.

Well, you're contradicting yourself here, since, as I've pointed out, if it assumes that the hypothetical rest frame of a photon is in fact not a valid reference frame, then we can't properly say anything about what time is doing in such a frame. But it's more important to point out that it doesn't actually matter what it assumes. The important part is that, after making those assumptions, the theory makes quantitative, measurable predictions about the results of various experiments, and that those results match what we see when we actually carry out those experiments.

For special relativity, there is no reference frame in which light can travel an infinite distance instantly. That's true whether we're using "classical" special relativity and treating light as a wave, or quantum electrodynamics (which incorporates special relativity), in which light can be considered to be composed of photons. If you want to create your own theory, where it is possible to have the rest frame of a photon, that might be a problem for your theory, but that doesn't make it so for relativity.

It's not that anyone wants to keep time dilation and length contraction. I think most physicists would have been happier if we could just use Newtonian mechanics. However, that doesn't match the results of experiment. We use special relativity because it works, not because we thought Einstein was a great guy.

Light doesn't travel instantaneously in any relativistic reference frame, and time doesn't "freeze" for any observer.

No, the thought experiments didn't change the mainstream view by themselves. It was the fact that the predictions based on those thought experiments match observation.

You can't be sitting on a photon, travelling at the speed of light. However, you can be sitting on a bullet travelling along with it at some speed less than c, and you'll work out all the same laws of physics that you would if you were instead watching the bullet zip past you with some significant velocity. You may not like it, but it works.

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Conserve energy. Commute with the Hamiltonian.