michel123456

How come that I find everything so extraordinary and you find it so natural? E=p for photons (not only, but for all massless particles) In this diagram, you have not one single value for E, you have the whole range from zero to infinite. For a specific mass (say mass4), each value of Energy corresponds to a single value of momentum. Which is not true for m=0. Suddenly a single value of mass corresponds to all values of energy and all values of momentum. So one could interpret the diagram stating that a photon can have a whole range of kinetic energy. How do you change the kinetic energy of a photon? On the other hand, P is frame dependent. So E (kinetic energy) is also frame dependent. But for photons, what does "frame dependent" mean, since all photons travel at the same velocity? Am I the only one alive here?

The name "lingual theory of everything" sounds bad. ToE is in fashion but I am sure next generations will laugh a lot with the idea. On the other hand the concept is not bad. Newton laws of motion are based on such kind of statements. Archimedes law is also a statement. The principle of least action is also a statement. So why not working with statements? The concept thus would be to find the first most fundamental statements. That's Mike attempt. It is difficult to reach the fundamentals (I have made such attempts in the past). For example "occur" includes the notion of time: there is nothing and suddenly something "occurs" that did not "occured" before. So Time is there already. Space is there too, because "occurence" presupposes space. Also "reason for it " includes a cause to effect relation, which is also related to time, and which should be explained by the fundamental statement and not be part of it. IOW the statement may be true but is not so fundamental. Same comments with 1. the statement may be true but is not so fundamental. Same with 1 & 2, plus something related to the principle of least action. Very interesting but not new. -------------------------- My shoot: Everything that is possible to happen do happen. The subtlety is in the word "possible". --------------- Apologize. It's a paraphrase of Brian Cox & Jeff Forshaw "everything that can happen does happen" from The Quantum Universe: Why All That Can Happen Does Happen

That's my problem too.

Other comment on the graph: The increase of energy is I suppose kinetic. The graph of Mass 4 for example represents a single mass that we put in increasing motion (acceleration). The graph of Mass-zero (photon), does it represent a single photon that we put in acceleration (how do we do that?), or the graph of multiple photons? Can we change the kinetic energy of a photon?

Yeap. I repeatedly complained about the position of the Speculations Forum. As far as I have understood, it is not an error. It is intentionally put near the waste basket.

(emphasis mine) You must mean that the relation becomes linear. -------------------------------------------------------------- (edit) Yes but the diagram does not show that a small mass travels at close to C. Although a photon MUST travel at C. _For massless photons, does the diagram go through zero? Is there a photon with E=0? _It is half an half hyperbola, you have erased the other parts of the graph because they represent negative (unphysical) values. (I noticed the careful IPI in the equation) _what about a graph with M on the abscissa and Energy on the ordinate?

You can call me Michel

How would you do this? Cutiing my sandwich in 2 parts. There is no law of physics that say that my 2 sandwich pieces would be given the slightest velocity because they are of smaller mass than the original one. If you continue cutting in pieces smaller and smaller at my knowledge there is nothing in existing physics that would input any velocity because you reduced the mass of the object. Not even for a neutrino I suppose.

Go to advanced search (the rotary symbol on the up right corner next to the search window). Make a search by date you will find the old threads. I had the same comment and Cap'n increased the time in the "my content' to 2 years.(only). That means your content will display only posts from the last 2 years.

They can, yes (it's hard to swallow but say yes). They are not obliged to. I mean if you reduce the mass of an object, you don't see it slowly going away at some velocity.

Thank you again, but the wiki article about light-cone coordinates is not particularly enlightening. So the "rest mass" of a photon is something that does not exist. It is not "something" which value is zero. It is not even a limit that particles tend to approach. IIRC there is nothing that propulses a particle of low mass at any speed close to C.

That's the first reasonable post I have seen around for a while. Rest mass is not just a name. It really means something for other particles. You are trying to elude the question. Can a photon be at rest? No. it is not physically possible. Is it correct to use an equation to describe an impossible physical state? i don't think so. If you want to mathematically describe unicorns, you will obtain at best a fairy tale, nothing more. surely not "science". Now, about observation: in which condition do we measure that the photon has zero mass?

You are correct. It is disappointing. --------------------- So you are arguing that I asked a wrong question. Swansont wrote: IOW there is no frame in which a photon has zero mass.

Yes or No, please. Besides, if not in Minkowski space-time what is the difference? besides#2, "all inertial frames" ; does that include the inertial frame in which a photon is at rest? -------------------- (edit) forget the besides #1 & #2. A Yes or No will do. I really don't understand you problem. ACG52 has no problem answering a so simple question. Can a photon be at rest?

Interestingly, in Greek mythology, the human beings were not created by Zeus (the king of gods) but by a Titan (another kind of supernatural being) called Prometheus. Prometheus is that one who wanted to help the creature he made from clay and gave him the knowledge of fire (light). He was further condamned for that through immense cruelty. The one who gives light in latin translation is Lucifer, another name for the Devil.

You'll have to wait for 10 seconds: http://www.scientificamerican.com/article.cfm?id=einsteins-only-known-expe

Yes or No please.

As much as i know the following; Forces of nature are transparent. At each level of dimension, all interactions apply. Even at the infinitesimal scale, gravity exist together with weak & strong interactions. Simply at those levels gravity is negligible. I guess, and I have read it somewhere, that even at the very smallest scale, expansion of space exists and acts but is soooooo weak that it is negligible. Its effects are even weaker than gravity. At a larger scale, the weak & strong interactions become negligible and other interactions take over; electromagnetism and gravity. Over very large scales, gravity takes over. Over veeeeery laaaarge scales, expansion of space takes over. Gravity gets weaker as a function of the square of distance. Expansion of space gets weaker as a function of distance.

Can a photon be at rest?

You are putting the equation above all. Can a photon be at rest? if Yes you can apply an equation, if No, no equation can stand.

It's an oxymoron: photons cannot be at rest point. Discussing the rest mass of a photon is like discussing the color of a unicorn. And stating that the rest mass of a photon is null is like saying the unicorns have no color (because there are no unicorns).

I vaguely remember some years ago a guy who used to make a fool of science forums. It was a young actor IIRC.

I suspect like a Chef would do with his sauce: you hold the tissue flat on a pan (if you have a large pan) as high as possible and then you draw quickly the pan down, vertically and quicker than gravity. The tissue should fall evenly, not flat, but with all 4 sides at the same velocity.

(emphasis mine) The graviton is (supposed to be) massless. So does the graviton interact with graviton while at the same time carrying gravity? It sounds like a bootstrapping.

Why tissue paper? i mean ; the centre of mass is a geometric feature, if you change the shape of the object (it easily happens with tissue paper) then the centre of mass will change location. For example if you wrap the tissue in donut shape, the centre of mass will not be on the tissue.