# photon

## A Photon has no mass. It can’t rest.

A) A Photon has no mass. B) A implies “It can’t rest”. C) Therefore it doesn’t have rest mass. D) Photon rest mass is zero.

Assertion and reasoning; A is correct. B is correct and follows from A. C is correct, it does follow from B. But D is incorrect it does not follow from A, B, or C. Its erroneous, a sloppy language that has been thought to be correct for ages now.

The trick is to realize there is no property called mass of photon — at-least in the same sense as it is for other particles with mass, therefore no rest mass. To say rest mass is zero is a special value of mass or rest mass. It just doesn’t have rest mass, as it neither has mass, nor rest, which are equivalent formulations, one leads to other. But A, B or C do not lead to D. They are not equivalent way of saying each other. They invalidate each other actually.

## What happens when squirrels do not move.

Stationary state and squirrels !

Okay so the squirrel isn’t moving around so much, giving a fuzzy image. We can call the instant during which the squirrel wasn’t moving akin to a “gross” stationary state.

But why is the railing of window fuzzy? It isn’t moving !

Diffraction.

Due to diffraction enough light is coming from the other side of the iron bar, to enable us to see whats there. That quadrangle is diffracting the light. But why its fuzzy?

Diffraction is by its own very nature even though purely classical in many sense, fuzzy towards energy if time window is small. [due to energy vs time uncertainty]

That is, full energy cycle isn’t available, because a small time window is chosen. If you time-lapse the photograph, diffraction will become quite insignificant. Although it might still be there depending on details.

## The time-energy uncertainty relation.

The time-energy uncertainty relation is a blessing in disguise which comes in handy to check various values that are quoted, so as to see if something is inconsistent or not. It’s very powerful in guiding to check if we are ourselves making something silly or not.

I have described in two recent articles — will link later, why.

1. One must be careful what energy and what time one is relating to, one just does not take any time and any energy and make a relation, in-fact one can see who is a good physicist from one who is a novice, by seeing how this relation is used by him.

This was joked by Landau: I can measure the energy and then look at my watch, time is just a parameter. But Einstein and Niels Bohr argued “during a very short time interval one must be careful what energy is allowed and what is not, there is a constraint on the windows of errors or uncertainties”.

2. Life-times are arbitrary variables as are energies, their means are not necessarily linked inversely as in case of the uncertainty relation itself, the latter gives a relation between the error-window which are linked inversely.

So watch out how much inconsistent description is given in an average article eg in Wikipedia and even in our text-books. These are training the future physicists very wrongly. One needs experience of solving good problems, one is to work in experiments of highest standard and understand them.

## Further OPERA of a comprehensible universe.

Following are the serious physics based remarks, analysis or studies I have made so far on OPERA collaboration’s experimental result or ones that can be read in this context. This measurement has surpassed in my opinion all bounds of doubt and uncertainty. What remains is an anomaly, in this article I will give some suggestions on how anomalies if any can be addressed and make other pertinent remarks.

Before that here are the serious articles on OPERA so far — only 1 humor based article is on OPERA with popular musical analogies, I will mention it just for the heck of it and presume it does not take any one away from scientific context, but then serious and good quality experiments aren’t necessarily understood by serious physicists who keep on making vague comments which is more of a danger toward science than just humor:

[in order of chronology, into past]

Article 1: The time energy uncertainty relation.

Article 2: Further OPERA of a comprehensible universe — the current blog you are reading.

Article 3: The sociology of skepticism.

Article 4: Why scientists think photon is mass-less.

Article 5: What do we know about photon ? (Light).

Article 6: Why the neutrino and photon break-up?  — You may avoid this it’s just humor.

Article 7: Fundamental things you should know about the neutrinos.

Article 8: Just a few implications of the OPERA neutrino result.

Article 10: Is a photon always moving at the speed-of-light? (current title: What are photons) — This one is before I knew anything called OPERA experiment exists, although written less than two weeks ago.

Article 11: Why nothing moves faster than light? — on my main blog site, written April this year.