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Photon path ..
#31
Think about how water waves get a direction. If you throw a stone into the water, you obtain a circular wave. To obtain some waves with a direction, you need need something more than a cause in a single point. Some mirror as in a flashlight, some hole on one side, or something greater which creates waves. And this "something greater", whatever it is, around will care about giving the information about the direction to the wave. But it will move too.
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#32
Schmelzer: "But it will more too."

I guess you mean "But it will move too." ?

Anyway, your point is a good one but doesn't entirely address this issue. Suppose you have an isotropic emitter, with no holes of any sort to direct the output. For instance, a hot sphere of tungsten. If it moves fast the photon emission will lose isotropy and become more intense in the direction of motion. Thus if it's going close to c it will start to look like a flashlight beam pointed forward (although some photons will still go out towards the back). So it's not about a guiding hole, or mirror. No matter how or why a photon is emitted orthogonally (to the side) when stationary, the relativistic addition of velocities dictates that it will slant forward when emitter is in motion. Why? AFAIK there's no known mechanical explanation. I wonder if dBB could provide one? But I'm pretty certain SR can't, nor does it attempt to.
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#33
Thanks, corrected.

And, no, the relativistic addition of velocities cares exactly about the point that the light cone remains the same. The Lorentz group is simply the group of transformations which leaves the light cone unchanged. So, (c,0,0) + (0,v,0) gives a velocity u with |u|=c. And (c,0,0) + (v,0,0) too. The light changes direction and frequency, but not the speed.

The question is why do you think the mechanical explanation given by an ether is not sufficient. (SR in itself does not even claim to attempt such an explanation, so it is out of discussion here.) I don't think dBB is relevant here, because the same problem appears with a ship and usual water waves too, already on a purely classical level and a complete mechanical explanation.
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#34
It's not the case that the ether explanation is not sufficient; I just didn't think about it. Main point was that ALT is looking for a mechanical (I think the word is applicable) explanation in terms of mainstream physics, but that simply isn't available.

My knowledge in this area is sketchy; but are you sure a ship behaves this way? For instance suppose I fire a bullet into water. Don't the waves spread out in a circle, unaffected by the bullet's direction? I thought it would make a bit of a track; and splash water in the forward direction. But the spread of the waves would be isotropic. Somewhat similar, a meteor always makes a circular crater (unless it's on a very extreme slant). When a plane makes a sonic boom, don't the sound waves spread isotropically from that point? We hear it equally in all directions. If not, don't bother to explain just say so. I'll address my ignorance by reading up on it.

Anyway since the ether model does give this exact, correct, velocity addition relation (I assume) that's a good point in its favor.

As for the light cone, it seems we have a misunderstanding. I'm referring to the way light spreads in 3-d space. If an isotropic source goes fast, apply relativistic addition to each light ray. The light that was at 90 degrees (when stationary) slants forward: that's what we (well, you and ALT) have been discussing. Of course everything in front of that slants even more forward. All, of course, still travelling at exactly c. That means that a full half (the forward hemisphere) of the light is now confined within a cone pointing forward, rather like a flashlight; so it can't be isotropic anymore. That "flashlight beam" can be called a "light cone" but it's NOT the relativistic 4-d light cone! That, of course, remains unchanged in both forward and back time directions, its boundaries still at 45 degrees (in a normal Penrose diagram).

Again if I'm misunderstanding I'll need to read up on it, don't waste your time explaining something elementary that I can look up on Wikipedia.
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#35
Ok, I have understood your point. What gets half of the energy is one hemisphere if the source is at rest but a forward looking cone for a moving source. Indeed. The other big known asymmetry is that the light forward is blue shifted, the light backward red shifted. The Doppler effect. Because blueshift means higher energy, this is similar.

So, without doubt, the speed of the source influences what radiation is created and how much in which direction. And to understand why one has to look at the details of some microscopic model, which provides some more details than a single moment at a single point. It is a short moment in a small region, but not infinitely short and infinitely small.
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#36
(05-18-2016, 07:26 AM)Schmelzer Wrote: And to understand why one has to look at the details of some microscopic model, which provides some more details than a single moment at a single point.  It is a short moment in a small region, but not infinitely short and infinitely small.

Yes that's exactly why I thought of dBB. Seems conceivable it could provide an explanation. Also ether model. Whole idea is to move beyond "it just happens by magic" and "you can't ask that question" to a mechanical explanation. May be these models won't work, but probably something will. At least, I'm 100% convinced the effort should be made - by a lot of physicists, not just one or two "radicals".

I still would like to see specific experiments (not just theory) to answer ALT's question! If I find any will post a link here.
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#37
Hi guys, and thank you both for the informative and interesting remarks. A few points;

EVERY real thing in nature has to be mechanical / physical, doesn't it ?

I have no idea what dBB is but will research it shortly.

When I first became interested in this, I came across a paper I by some physicist who makes the issue very clear, and of course, infinitely better than I. I am trying hard to remember his name and find that paper. I think you will find it fascinating. I recall his point that if Einstein had the benefit of a modern day laser, he would have never come up with SR.
I will keep trying to find it - I may have a copy of it in an old computer I will be able to access this weekend.
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#38
dBB = "de Broglie-Bohm" theory. See http://ilja-schmelzer.de/forum/forumdisplay.php?fid=6. Schmelzer has done a lot of work in this area.

Everything in nature has to be physical with the exception of consciousness which may or may not be. We should always look for a "mechanical" explanation. Too often modern science says "that's just how it works" and refuses to look further; that's bad. Still, some physical things may not be "mechanical".

For instance, off the top of my head: the universe may be a "Virtual Reality" simulation. In that case nothing, at bottom, can really be explained mechanically. Then there are some scientists who limit the scope of the word "mechanical" and wouldn't include explanations involving, say, entropy, non-locality, probability and other subtle concepts. It becomes a question of semantics as much as anything else.

Bottom line, at the current state of knowledge we should not give up on mechanical explanations for anything, even consciousness.

I'd like to see the paper ... interesting to note that Einstein, in 1917, came up with "stimulated emission" which is the theoretical basis of the laser. It took about 40 years to actually build one, though.
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#39
dBB; thanks for the link. I will peruse it shortly.

Semantics - indeed. What I was getting to, I think, is that it's perhaps an oxymoron to call something 'metaphysical' or relativistic, ie, in some sense, separate to reality or transcending reality. Lets say a better term is 'natural' rather than 'supernatural' - all things must be natural.

The paper; I have located a copy of it on my old computer. It is called;

'A Report On How The Optical Laser Disproves The Special Theory Of Relativity'
by one Richard O Calkins.
It was submitted for peer review (where ?) in 2013 according to the paper itself.

I can't seem to find a link to it for download, anywhere, including his web site.
I have emailed him and asked him for a link. Absent of which, I can post all forty odd pages here, (not a good idea as it has many diagrams and I'm not sure how they will appear) or somehow send to you (or anyone else interested). I really think you will find it very interesting.

PS, if you search for it yourself, please be aware that as a result of it, others, mainly science writers, have also written, and those writings have very similar titles. Therefore, you should look for the exact title, above.
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#40
Thanks ALT,

I see from reviews that he feels the directionality of a laser disproves SR. This seems related to your question in this thread, and so it would make sense for you to summarize the relevant argument here, wouldn't it?

Reading Calkin's site I agree with at least one of his points: SR's "enthronement" is about sociology not just physics. Like so many others, I came innocently to the physics community, 40 years ago, to point out certain problems I naively thought they'd missed. Like so many others, it took years of fanatical rejection to begin to realize: they already know my "brilliant theory" perfectly well! But ... there are other issues involved.

Oh well, such is life. Anyway I'll be happy to hear Calkin's arguments, but will probably not be too surprised by any of them. Please give us a summary. On this site we stick to the physics exclusively, please.

[edit] I found more info on Calkin's site and am NOT impressed. He says gravity does not bend light! Instead the Sun's atmosphere refracts it. AFAIK this is not correct at all. Admittedly I've never looked through a telescope at gravitational lensing phenomena, but can't believe all those astronomers are faking those pictures! And there are many other tests of this fact. Calkin's objection would have been allowable back in 1920, but not today. As always I'll listen to anyone, but if he can't address these points give up.

Based on his artwork and the rest of his site I'm sure he's a fine gentleman; but misguided. Argument to the contrary is welcome - once.
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