non-zero mass photons?

A global team of scientists, including a University of Mississippi physicist, has determined the best constraint on the mass of photons so far, using observations of super-massive black holes. The research findings appear in the September issue of Physical Review Letters, one of the most prestigious, peer-reviewed academic journals in the field. "Black hole bombs and photon mass bounds" is co-authored by Emanuele Berti, UM assistant professor of physics and astronomy, along with fellow researchers Paolo Pani, Vitor Cardoso, Leonardo Gualtieri and Akihiro Ishibashi. This paper details how the scientists, who work in Portugal, Italy, Japan and the U.S., found a way to use astrophysical observations to test a fundamental aspect of the Standard Model – namely, that photons have no mass – better than anyone before. Read more at: phys.org...

I always suspected that photons might have a super small (rest)mass, ever since I heard about "quanta". The picture didnt make sense to me if photons were massless for a long time. Then you get taught that they dont have mass and you learn about the higgs interaction, and qed and it starts to make sense. Wouldnt it be crazy if photons have mass?

reply to post by ubeenhad


If anything, this study further confirms that photons have zero rest mass.
Their conclusion:

"With this technique, we have succeeded in constraining the mass of the photon to unprecedented levels: the mass must be one hundred billion of billions times smaller than the present constraint on the neutrino mass, which is about two electron-volts."

The fact that photons travel at the speed of light should be proof enough that they have zero rest mass.

reply to post by CLPrime


Yea if E = pc
But somethings got to give somewere, thought you pseudos would be all over this, like the FTL Neutrinos!

Originally posted by ubeenhad
Wouldnt it be crazy if photons have mass?

Photons are never at rest so it's impossible to measure their mass when they're at rest.

As the following source suggests, we can't experimentally prove the rest mass is zero but as the above study shows we might place lower maximum limits on it:

math.ucr.edu...

Is there any experimental evidence that the photon has zero rest mass?

Alternative theories of the photon include a term that behaves like a mass, and this gives rise to the very advanced idea of a "massive photon". If the rest mass of the photon were non-zero, the theory of quantum electrodynamics would be "in trouble" primarily through loss of gauge invariance, which would make it non-renormalisable; also, charge conservation would no longer be absolutely guaranteed, as it is if photons have zero rest mass. But regardless of what any theory might predict, it is still necessary to check this prediction by doing an experiment.

It is almost certainly impossible to do any experiment that would establish the photon rest mass to be exactly zero. The best we can hope to do is place limits on it.

And that's what's happened in the OP linked article, we've placed limits on it.

Seems like your missing the cool science here. They found another way to use black holes to study the fundamental structure of stuff! With the limits on experimental particle physics fastly approaching we are going to HAVE to rely on astrphysics!

reply to post by ubeenhad


Wouldn't observing photon interaction within a super dense material like tungsten provide similarly useful data?

I guess it'd have to be specific frequencies of light caring the photons, though, when observing them within the respective material


Cool stuff in research these days!

reply to post by ubeenhad

That's a good point. We can only make particle accelerators so large. But there are mysterious particles striking the Earth with far greater energies than we can create in an earthly particle accelerator, mysterious because we don't even know how they get such high energies.

So to continue researching higher energies to explore things like string theory, we would need to make use of these cosmic particles, which is hard to do, since they are so few and far between.

But yes, supermassive black holes are a cool tool for advancing science.

Originally posted by ubeenhad

But somethings got to give somewere

What's got to give?

Regardless, the experiment itself is interesting, though it's really just a marginal issue given the immense body of observational evidence in favour of Relativity, which necessitates the photon's zero rest mass. But it does have to be done, since science does (or should) require the tying up of these sorts of loose ends.

Originally posted by Soloro
Wouldn't observing photon interaction within a super dense material like tungsten provide similarly useful data?

You would need a lot of tungsten, and even if you could put enough of it in one place to provide comparable results, it would still collapse into a black hole, wouldn't it?

reply to post by CLPrime


Minimal yes, but could be key to unifying gravity.
Relativistic models wont work if we ever wanna know things like what happened at the instance of the big bang.

Edit: whats got to give? um gravity as spacetime geometry or quantized
Edit: And as with every particle physics discovery these days, novel appliactions in more controlled Qunatum Computing(just speculating)

reply to post by ubeenhad


You seem to have more understanding than you were letting on earlier this morning.

I've thought this too, it seems that anything that transfers energy while it is moving would surely have some sort of mass at rest, however minuscule it would be.

Would be interesting to get some experiments up an going with cameras like this that work with both visible light and the rest of the electromagnetic spectrum.

Geniuses at MIT capture images at 1trillion fps!!!

reply to post by twistedlogic


That word "seem" is your problem.

Everyone seems like something especially on the internet. Very rarely is it accurate.

I said nothing on the other topic for you to doubt my intelligence. Infact, if you searched my post history before yall started in on me, you would see i have given much more factual information than i have in this topic, BEFORE i posted the rant about pseudoscience. Yall just didnt like what i had to say so you insulted me personally. And my grammar. Which, i can admit is terrible. you should see my handwriting.

Like I did last night, I invite anyone from the other topic to debate some science if they are off the grammar kick.

reply to post by ubeenhad


Errr...not arguing, I'm agreeing that through logical analysis photons surely must have some sort of mass. And not once did I jab at your grammar. Just tried to differentiate you between being a troll or not. Sorry i don't read everyones post history before i comment on a thread....

And that first sentence was a compliment, not opening the door to last nights discussion.

PS derailing your own threads is a good way of getting them closed.

reply to post by twistedlogic

If troll means i will talk # about dumb science then i am a troll.
Troll me up son.

reply to post by ubeenhad


Lol its responses like that, that make you sound like a troll. No personal jabs at you, but responding with a hostile tone.

Theres no winning with you.

Adios my friend, take it easy.

Originally posted by twistedlogic
reply to post by ubeenhad

 

Lol its responses like that, that make you sound like a troll. No personal jabs at you, but responding with a hostile tone.

Theres no winning with you.

Adios my friend, take it easy.

Your the tool that brought up the other thread. Bring some more of that ignorant stuff her tonight. Im sober.