E ≠ mc²?Follow

The difference between a law and a theory is that the law doesn't explain the phenomenon, not that one is necessarily stronger than the other. Theories will always be theories, laws will always be laws.

theoretical != hypothetical

It's the measured speed of a photon in a vacuum. Which since we assume that a photon is massless must therefore be the maximum speed at which an electromagnetic particle can travel. But if we're wrong, and photons do have mass (presumably incredibly small mass), then the true maximum speed would be just a tiny bit higher. A mass small enough that we haven't detected it yet would result in a discrepancy in that speed that is also small enough to fall within the margin of error of other tests we've performed, yes?

Holy shit, I guess we can add Physics to the very long list of things you know nothing about.

Let's start with what I "think" you mean. When you say "have mass" do you actually mean "are matter"? I started to type a basic explanation of quantum electrodynamics, then I realized who I was replying to, and regained my senses.

Anyway, that aside, could you explain why if Photons had "mass", and for the sake of sanity, let's set "mass" to mean what's it mean for the last 70 years of physics before you answer: invariant non relativistic mass, why this would allow neutrinos to exceed C? While we're here, neutrinos have mass, they have to, they oscillate, so let's short circuit any crazy ideas about photons somehow having "more mass" than neutrinos. They don't.

I keep putting "mass" quotes, incidentally, because photons, essentially by definition. If they did, they'd be something else, not photons, and light would work entirely differently (and a lot differently) than has ever been observed. A LOT DIFFERENTLY. The idea that photons have mass, and this is in no way an exaggeration, is similar to the idea that moon does contain a green cheese core.

This is in interesting anomaly. It'd be fascinating if it could be replicated, and that would drastically change physics as we know it. I'd really enjoy that.

Sadly, I think it's more likely I'll get to ride my pet unicorn than that happening.

Let's wait for the PR before we get too lathered up.

It doesn't. It means that C is slightly faster than we think it is. Or did you miss that the last handful of times I explained it in clear English simple enough for a 5th grader to understand?



And yet, amazingly, people who actually work in the field aren't 100% sure. Similarly, while they assume that photons have no mass, and have set an upper limit on what the mass of a photon could be without violating observed behavior, they don't actually know that for sure either.



You declaring it so (in bold nonetheless) doesn't actually make it true. I know your ego is larger than the state of New Hampshire, but that just means you're more likely to be self deluded than anything else.



Only the parts of the definition of a photon that are completely circular and dependent on the assumption that photons are massless and thus the speed they travel at is the speed that massless particles travel at and is thus the fastest speed a particle can travel and is thus the basis point from which we calculate all other relative particle speeds is dependent on photons having no mass.

You do get that we use the photon for this pretty much only because it's super easy to detect, right? It's pretty much arbitrary. We picked it because it appeared to be the fastest moving thing we could detect. So we declare it the fastest, assume it's massless (because we can't find anything faster) and move on. Please tell me you can grasp how finding something that appears to move faster than light, changes the very assumptions you base your argument on

If neutrinos were easy to detect instead of ridiculously hard, can you explain any reason why we wouldn't use them as the basis for determining C? Think really hard about that before answering because it's a biggie.



Nope. You're grossly over-exaggerating things. It doesn't change anything at all except that C is really just slightly faster than we thought (and we're talking like .0000001% faster, so an amount that we can barely even measure, but into which the measured speed of a neutrino can fit). As I stated earlier, we already know that ambient conditions can cause a photon to move slower than the "speed of light" (even a hell of a lot slower in some cases). We do experiments in which we slow photons down all the time. Amazingly, the laws of physics don't fall apart at all.

Aside from insisting that it would make things work "a lot differently", can you actually name any way in which it would make things work differently? Again, you insisting it must be true doesn't make it true. There's a whole set of physics thought experiments which ask specifically what would happen if photons actually had a very very small mass. The answer is pretty much "not much".



Yeah. It's an exaggeration. But it's what you do best, so keep at it!



More or less drastically than the possibility that photons actually do have a tiny mass?

What's funny is that I'm applying Occam's Razor here. Assuming the measurements are correct, then assuming that the current measured speed of photos in a vacuum is *not* actually the fastest speed a particle can travel (That's "C" btw, which works in the equations regardless what we use to measure it) is the simplest explanation. Assigning a very very small mass to photons is honestly the least disruptive way to allow for that finding. There are others as well, which require assuming ambient conditions in the vacuum which we have previously assumed don't slow down photons at all (which I explained in an earlier post as well).

Barring that, you kinda have to re-write whole sections of our understanding of physics. At it's most basic Smash, if neutrinos really are traveling faster than the measured speed of light, then the measured speed of light cannot actually be C, without tossing out the entire meaning of the value of C in physics.

Edited, Sep 23rd 2011 6:25pm by gbaji

No. I'm not joking. And if you stop and step back for a second, you'll realize that I'm correct. How the hell do you think we measured C? We started with the assumption that light was the fastest particle and measured the speed of photons. All of the equations we use in general relativity rely on that value, but if the value is very very very slightly off, it doesn't change a damn thing. It's a constant in the equations. You could plug 5 in there and the equations would work. They wouldn't match the world we see around us, but the equations themselves would still be correct. That's the very nature of a constant.

A value of C that is nearly imperceptibly higher than what we've previously assumed it to be does not change a damn thing in physics.



No. C has a very specific meaning in physics. But the value we assign to C is based solely on measuring the speed of photons because... wait for it... photos are/were the fastest particles we'd ever measured. Based on that, we assume they are massless (but it's not necessary for the model to work), and that nothing can go faster than "the speed of light". But it's really C that nothing can go faster than. We can't measure C. We can only measure particles which we think are traveling at C.


Once you get past the assumption that C must be the same exact value as the speed of light in a vacuum, you realize that it doesn't break anything for C to be slightly faster than light. The Lorentz factor (and a whole bunch of other stuff btw) is not defined relative to the speed of a photon. It's defined relative to C. The value of C is simply assumed to be the same as the speed of a photon in a vacuum. If it's slightly higher, it doesn't break anything at all. Why do you assume it would?


You're literally getting caught up in a label.

False dilemma? Really? There are vastly more possibilities than what you're allowing here.

And please, don't presume to lecture me on the origins and significance of c. I'm somewhat doubting if you even knew what a neutrino was before coming into this thread now.

Name one. As you yourself pointed out, the significance of C as the presumed fastest speed that an electromagnetic particle can travel is critical to relativity as whole.

The exact value of that speed is *not*.

We can either assume that we got the value slightly wrong *or* assume that other particles can travel faster than C. It's not a false dilemma. These are the only two possibilities. Surely you see that. It's two sets that make up the whole here. Either C is the fastest speed of a particle, in which case the neutrino can't go faster than it, or it's not. If it's not, then large portions of relativity break down. If it is, and neutrinos are faster than photons, then C must be faster than photons as well.

You don't need to understand an ounce of physics to follow this argument. It's simple logic.



And yet, you seem unable to really grasp what I'm talking about in anything other than a "regurgitated from a textbook" way. It's shocking that people with educations can't follow such a simple logical argument.


And for the record, let me repeat that we're assuming that the speed of neutrinos are in fact exceeding that of photons here and it's not a measuring error, or some other factor that just makes it appear like they are.

Edited, Sep 23rd 2011 7:36pm by gbaji

And for the record, let me repeat that we're assuming that the speed of neutrinos are in fact exceeding that of photons here and it's not a measuring error, or some other factor that just makes it appear like they are.

We understand. Neutrinos move faster than photons because photons have some small mass that's greater than the mass of neutrinos, so it isn't that anything moves faster than C, because photons move slower than C because of their mass.

Not confusing, just mathematically impossible and idiotic.

Stop right there. This is the assumed case right? Let's ignore the "why" for the moment and just look at the "what":

C is the fastest speed that particles can travel.
Neutrinos travel faster than photons.
Both neutrinos and photons are particles.

Therefore C must be faster than the speed of photons.


This incredibly simple logical formulation encapsulates the entire question we're discussing. That's really all there is here.


Either that conclusion is true, or one of the other two assumptions are incorrect. Which means either that C isn't actually the fastest speed the particles can travel *or* that neutrinos and photons are not both particles (specifically, neutrinos would have to not be particles). To change either assumption would require massive re-writing of our understanding of physics.

Occam's razor says that C is faster than the speed of a photon in a vacuum. Doesn't mean it's true, but it's the most reasonable starting assumption to make (outside of the obvious measurement error of course!). I've presented a couple possible explanations for why photons might move slightly slower than C. Having a tiny mass is only one. Heck, there could be dozens. But no matter what that reason is doesn't change the basic logical conclusion I wrote above.


You really can't see this? Amazing!

Edited, Sep 23rd 2011 8:00pm by gbaji

C is the fastest speed that particles can travel.
Neutrinos travel faster than photons.
Both neutrinos and photons are particles.

Therefore C must be faster than the speed of photons.


This incredibly simple logical formulation encapsulates the entire question we're discussing. That's really all there is here.


Yes, tautologies are tautologies.

No, if the results of this experiment are confirmed, there's not an incredibly simple explanation. There's a mindbogglingly complex problem that may result in some sort of elegant solution in no way related to changing the "speed" of C.

Lots of magical science in this thread.

Has no one posted this yet? Really?