Higgs Boson Discovered?!

[sol invictus]

According to experiment, it costs 511keV to make an electron, plus that tip for the neutron etc. Since the Higgs condensate is everywhere, making claims about the cost of an electron without it are not scientific.

Experiment says that it costs 511keV to make an electron, yes. But the claim that the Higgs is responsible is anything but "unscientific". What do you think science is? It's coming up with theories to try to explain experiment, and then testing them. And that's precisely what the Higgs mechanism is - it's a theory to explain where that 511keV comes from, and like all good theories, it makes a bunch of other predictions too. One of them is the prediction that the Higgs particles exists, and that it has certain very specific properties and interactions. That prediction looks like it has now been confirmed.

And the theory - correct or not - is 100% consistent with E=mc^2.

Do "we" know whether the electron gets its mass from interaction with the Higgs field, or is it just an assumption?

Again, it's not an assumption - it's a theory, one which may or may not be correct, but which is manifestly scientific because it makes testable predictions.

 

[sol invictus]

Actually, this is a part that you have completely wrong but that I think Sol has wrong as well.

No, I don't have it wrong. In the standard model, the electron's mass comes from the electron's Yukawa coupling to the Higgs field.

The Higgs mechanism addresses gauge bosons in a gauge theory. In the particular context of the Standard Model, the Higgs mechanism gives an electroweak theory with massive W and Z bosons and a massless photon, where previous attempts could only predict they were all massless. It actually says nothing at all about the mass of the electron, which was already adequately explained by QED around the 1940s.

Sorry, but you're wrong. Yes, in some sense the main role of the Higgs is not to account for fermion masses - it's to spontaneously break electroweak symmetry, and hence provide masses for the W and Z bosons. And it's also true that in general, one can write down masses for fermions without a Higgs.

But, in the standard model the left-handed particles have different gauge transformations than right-handed particles. An ordinary (non-Higgs) mass for the electron requires a coupling between the left and right-handed electron - but that's not gauge invariant, and hence nonsense. Instead, you need the higgs field (which has the opposite gauge transform as the left-handed fermions) to combine them. When the higgs field is non-zero - i.e. when it's condensed - that's a mass. When it's zero, the mass is zero.

Among other things, this means the higgs particle couples to fermions exactly proportionally to their mass, which is a testable prediction (among others). Since the top quark is the heaviest fermion, the higgs couples very strongly to it and like to decay to it.

 

[sol invictus]

My understanding was that while part of the Higgs mass comes from a self-interaction, there's a free parameter that gives the Higgs bosons mass even if the Higgs field were zero?

Paging theoreticians. Paging theoreticians.

If the Higgs field were zero, the Higgs "particle" would be a tachyon (a field with negative mass squared). That's why it condenses.

 

[Farsight]

Farsight, if you work through the math behind what Tubbythin is saying, you will find that the more general relationship between relativistic energy and momentum (neglecting the four-vector nature of momentum) comes out to:

E² = (pc)² + (mc²)²
which for massless particles, like photons, comes out to (m = 0)...

E = pc

No offense, but this is a pretty straightforward calculation requiring only a basic understanding of SR and some algebra. For someone claiming to be so well versed in SR, this isn't the kind of mistake you should be making.

I didn't make any mistake, I referred to the expression in post 430 on page 11. I also referred to it in post 473 on page 12 where I said this: Take a look at energy-momentum relation on wikipedia. See where it says the equation simplifies to E=mc² for a body in its rest frame. Then a bit lower down it says if the object is massless then the energy momentum relation reduces to E=pc as is the case for a photon.

 

[Farsight]

Einstein never said that the mass of a body doesn't depend on the Higgs mechanism. You did.

He didn't say the mass of a body doesn't depend on fairies either.

Einstein also never said that the mass of a body cannot depend on how strongly that body interacts with various fields. One reason Einstein never said this is because he never had any evidence to support such a claim. Another reason he never said it is because he knew perfectly well that the energy content (and therefore the mass) of a body can and often does depend on how that body interacts with various other fields.

You're airbrushing over history Stimpson.

Again, there is nothing contradictory about saying that a body's mass is a measure of its energy content and that its mass depends on how it interacts with the Higgs field, as long as it is also the case that the energy content of that body also depends on how it interacts with the Higgs field (which it does).

Yes there is. It either depends on its energy content or on something else.

The fact remains that the standard model does not claim that the inertia of a particle ever depends on the Higgs mechanism. The rest mass does. And rest mass is not the same thing as inertia.

Unless it's a body at rest, which is what Einstein was talking about with those radium salts.

And like I said before, if you object to the term "mass" being used to refer to inertial mass, then you need to stop claiming that mass is a measure of energy content, because it quite demonstrably is not.

And there we have it. Einstein said "The mass of a body is a measure of its energy-content", and Stimpson say "it most demonstrably is not".

Show me where Einstein ever said that the energy of a particle cannot depend on how strongly that particle interacts with various fields. He never said it, because he knew better.

Oh don't insult our intelligence, Stimpson. You show me where Einstein ever said that the energy of a particle cannot depend on how strongly that particle interacts with fairies.

Put bluntly, you are making a complete fool of yourself. Nobody here is impressed with your feigned expertise. Nobody reading this thread actually believes that you know what you are talking about. And nobody cares if you put them on ignore for being mean to you.

That's a clear insult, from somebody who dismisses Einstein to boot. You know the rules. I'm not talking to you about this any more. Next.

 

[dafydd]

You know the rules. I'm not talking to you about this any more. Next.

How long will it be before you talk only to yourself?

 

[Farsight]

Completely and utterly false. Wrong. Incorrect. Not what we observe. Cannot be substantiated by experiment.

Light waves are always associated with angular momentum. Go watch Susskind's lecture.

You can't have a reasonable discussion about physics with someone who believes that waves are always associated with angular momentum. My evidence? This thread.

You aren't. You're just chipping in with snide comments. Next.

 

[sol invictus]

...waves are always associated with angular momentum.

Completely and utterly false. Wrong. Incorrect. Not what we observe. Cannot be substantiated by experiment.

Light waves are always associated with angular momentum.

We see what you did there, Farsight. Yes, light waves often carry angular momentum, and individual photons always do. But waves in general are not always associated with angular momentum. Sound waves, for example, do not have intrinsic angular momentum. And you weren't only talking about light. Here's the full quote:

Don't put words in my mouth. Photons are waves, waves are always associated with angular momentum. Look at wind waves. See the pictures on the right. A wave makes things go round.

Saying "A wave makes things go round" makes as much sense as saying "A horse makes things go round".

Admit your mistake and move on. Can you do that?

 

[Stimpson J. Cat]

He didn't say the mass of a body doesn't depend on fairies either.

Well, if somebody was claiming that fairies were responsible for electrons having a non-zero rest mass, and you argued that Einstein said "the mass of a body depends on its energy content, not the fairy mechanism", then your argument would be wrong. Einstein never said that. Likewise he never said that the mass of a body does not depend on the Higgs mechanism. So again, you are wrong for saying that he did.

Einstein also never said that the mass of a body cannot depend on how strongly that body interacts with various fields. One reason Einstein never said this is because he never had any evidence to support such a claim. Another reason he never said it is because he knew perfectly well that the energy content (and therefore the mass) of a body can and often does depend on how that body interacts with various other fields.

You're airbrushing over history Stimpson.

No, I am not. Einstein died before the Higgs mechanism was proposed, but as has already been explained to you, this is not the only mechanism by which interactions with fields are known to contribute to the mass of particles. This was known well before Einstein's death.

Yes there is. It either depends on its energy content or on something else.

Does my net pay depend on my gross salary? Of course it does.
Does my net pay depend on my tax rate? Of course it does.

You're just being silly here. I don't think you even believe the ridiculous arguments you are presenting anymore. I think you just can't bring yourself to admit that any of the arguments you have made are flawed.

And like I said before, if you object to the term "mass" being used to refer to inertial mass, then you need to stop claiming that mass is a measure of energy content, because it quite demonstrably is not.

And there we have it. Einstein said "The mass of a body is a measure of its energy-content", and Stimpson say "it most demonstrably is not".

Nice try, but I serious doubt anybody reading this thread is stupid enough to fall for such a blatant misrepresentation.

Oh don't insult our intelligence, Stimpson. You show me where Einstein ever said that the energy of a particle cannot depend on how strongly that particle interacts with fairies.

What's this "our" crap about? I doubt very seriously that you can find a single person involved in this discussion who actually agrees with you on any of this.

hat's a clear insult, from somebody who dismisses Einstein to boot. You know the rules. I'm not talking to you about this any more. Next.

Oh no! Farsight says he won't talk to me anymore.

Wait, that's right. I don't care. Seriously, Farsight, if you think anything I have posted on this thread is for your benefit, or that I ever thought there was any chance of convincing you of anything, you are even more deluded than I thought. I could not possibly care less whether you choose to talk to me or not. I am still going to point out why what you are saying is incorrect.

In fact, since even when you do respond to my posts you don't actually address my points in any kind of coherent way, it doesn't actually matter whether you respond to me or not. If anything we are all better off if you don't. That just means less noise.

Of course the best scenario would be if you just stopped posting your nonsense altogether. But until that happens, you will just have to put up with Physicists like me pointing out that you are don't actually know what you are talking about and that you your claims and theories are complete nonsense. You see, you don't actually make the rules here. You can ignore me, but you can't make me go away any more than I can make you go away.

 

[W.D.Clinger]

This has been entertaining...in "the smartest man in the world just jumped out of the plane wearing my book pack" sort of way.

Maybe you were trying to argue that energy is the same as scalar momentum multiplied by the speed of light. If so, we can repeat the above calculation to get this:

E² = m²c⁴ + E²​

Unless you want to argue that every cannonball has zero mass, that interpretation doesn't work either.

Don't put words in my mouth.

In Farsight's own words, written a couple of days later, with my highlighting:

And like space and time, energy and momentum are merely two aspects of the same thing called energy-momentum. You always divide by c to go from one to the other, for example for a photon energy E = hf whilst momentum p = hf/c. Hence momentum p=E/c.

So Farsight has confirmed, using his own words, that his interpretation fails at the level of eighth-grade algebra.

LOL, I've got maths A level, I did more maths at university when I did a Computer Science degree, and I've done maths tutoring up to A-level.

Before I infer anything about math education in the UK, I should consider the possibility that Farsight is an outlier.

My physics knowledge far exceeds that of other posters here.

When citing Wikipedia articles that refute your argument is the best you can do, your argument is laughable.

As everyone who knows anything about physics has been trying to tell you: Energy and momentum are related, but they aren't the same thing.

 

[Tubbythin]

I didn't make any mistake, I referred to the expression in post 430 on page 11. I also referred to it in post 473 on page 12 where I said this: Take a look at energy-momentum relation on wikipedia. See where it says the equation simplifies to E=mc² for a body in its rest frame. Then a bit lower down it says if the object is massless then the energy momentum relation reduces to E=pc as is the case for a photon.

You explicitly said, when discussing the energy of an electron:

The third one, because E=mc² means m=E/c², so if m=0 then E=0 too. Next!

 

[Farsight]

I'm not sure Cuddles is talking to me, but I'll have a look anyway.

In fact, this is beautiful demonstration of just how little Farsight understands.

No, he isn't talking to me. I wonder, does Cuddles fight shy of talking to me because he's afraid I'll embarrass him with my understanding? OK, let's see what he's saying.

The Higgs field effectively is an aether just, as you say, not quite in the way the term was originally used.

Fair enough. The only people who have a bad attitude to aether are people who don't know much physics. There's loads of aether papers on arXiv.

In fact, the path leading up to the work of Higgs and others was partly based on the early work of plasma physicist Anderson (check the references in the paper I linked earlier). Anderson wasn't actually particularly interested in that area of particle physics. What he was thinking about was how the universe might look to a hypothetical being that lived inside a plasma, and in particular what laws of physics such a being might deduce from observations.

Again, fair enough.

Photons have zero rest mass, and as a consequence can have any energy. Massive particles cannot have any possible energy, since they have a minimum energy due to their mass. In a plasma, there is a phenomenon known as the plasma frequency.

Which ties in with what I've been saying about standing waves, where wave harmonics apply.

Above this frequency photons can penetrate the plasma, but below it they can't. This is how radio waves can bounce off the ionosphere, for example. That means the hypothetical being inside a plasma would observe photons to have a minimum energy, and would therefore deduce that they have mass.

No they wouldn't. They say that those massless photons add mass to the system when they trapped inside a box made out of "ionosphere" plasma".

There is also another related phenomenon that light consists of transverse waves with no longitudinal component, while in a plasma they excite longitudinal oscillations called plasmons, and this also implies a massive particle.

A photon is massless. A plasmon isn't, because it's like "the system".

So what Anderson had done was show that given a particular kind of background, a particle which would normally be expected to be massless could actually behave in every way as though they had mass. In a universe filled with a uniform plasma, photons would have mass due to their interaction with this all-pervading condensate.

Not true. And the Higgs mechanism doesn't give photons mass.

In effect, we're the being in Anderson's plasma. Without knowing about the Higgs field, we observe certain particles to have mass that we wouldn't expect.

Not true. We expect a particle at rest to have mass because it's a body, and the mass of a body is a measure of its energy-content.

Interaction with the plasma/Higgs condensate simply explains why that happens.

LOL. Then explain it.

Of course, the plasma in that case is non-relativistic and effectively matches early ideas of the aether - a plasma gives you a preferred frame of reference and we know there isn't one. As Farsight says, we've already disproved that this kind of aether exists.

But Einstein did talk about the aether of general relativity in his 1920 Leyden Address. And I said if the Higgs mechanism was responsible for both photon momentum and electron mass that would be OK. Only then it's just four-potential. So it isn't.

What Farsight completely misses is that we've only disproved this specific kind of aether.

No I haven't. See above.

The Michelson-Morley experiment says absolutely nothing about a relativistic aether, and neither does Einstein

Wrong. See his 1920 Leyden Address.

...relativity, or anything else. Far from the Higgs mechanism ignoring this, the fundamental basis of the whole thing is the discovery of a way to generalise Anderson's work to what is essentially a relativistic aether. The entire reason this work was important is not because physicists are all idiots who just ignored Einstein's work

They aren't all idiots. A lot of them oppose the Higgs mechanism and remind us of E=mc².

it's because they found a way to describe an aether that is entirely consistent with Einstein's work.

Apart from that E=mc². And like I pointed out to sol, it's an assumption that the Higgs mechanism gives the electron its mass.

It's generally not referred to as an aether because that term is associated with the long discredited non-relativistic aether. Farsight nicely demonstrates the sort of confusion that can cause in people who don't know anything about the field.

But obviously I know plenty.

Now, the idea of some weird substance filling the whole universe might sound a bit crazy, but it's not actually a new or unusual idea at all. OK, the Higgs field is present everywhere in the universe. Well so is the gravitational field. So is the electromagnetic field.

It's four-potential. Light is a wave in it. There is no electromagnetic field filling space because electrons don't all accelerate thataway.

And we've long accepted that empty vacuum is actually filled with particles constantly popping in and out of existence.

No we haven't. It doesn't happen. We have no experimental evidence to support this notion. Vacuum fluctuations are not the same as particles popping in and out of existence.

The behaviour of all particles is already governed by their interaction with these background fields of the universe. Adding in another one isn't really such a big step, especially if it explains a bunch of stuff that no-one's managed to explain in any other way.

I've explained it any other way. The explanation I gave is just a rehash of Einstein's explanation. But neither you nor anybody else has explained the Higgs mechanism.

 

[Farsight]

Actually, this is a part that you have completely wrong but that I think Sol has wrong as well. The Higgs mechanism addresses gauge bosons in a gauge theory. In the particular context of the Standard Model, the Higgs mechanism gives an electroweak theory with massive W and Z bosons and a massless photon, where previous attempts could only predict they were all massless. It actually says nothing at all about the mass of the electron, which was already adequately explained by QED around the 1940s.

Like I pointed out to sol, the Higgs mechanism is assumed to be responsible for electron mass. And sorry to use bolding, but this is important: please give a reference for the QED explanation of electron mass.

 

[Farsight]

I'm going to make an exception to my own rule here, because this is choice:

Not a theorist...

For an experimentalist, you're amazingly adept at dismissing hard scientific experimental evidence.

...so a bit out of my depth

No comment.

My understanding is that there *is* a gauge-invariance problem with any (non-Higgs-based) fermion masses in the Standard Model. My understanding is, further, that since you really need to posit a Higgs field to explain the gauge boson masses...

We'll turn the Sauron gaze to them one day.

...you might as well (but aren't strictly forced to) reuse it to give you nice gauge-invariant fermion masses, too.

Not if you understand E=mc² and electron diffraction and atomic orbitals where "electrons exist as standing waves". Then you look at h and harmonics.

If there's a necessary connection between these two, no one has ever explained it to me.

No. And you can't explain why the Higgs field gives the electron its mass. And I didn't even mention quarks.

However: now that the LHC has actually seen the Higgs, and in particular since it's seen *both* a fermion-coupling decay (top loops leading to higgs gamma gamma) and a gauge-boson-coupling decay (H->ZZ and H->WW) of what appears to be the same 125 GeV particle ... well, that basically confirms the simple picture above.

All they've seen is a bump on a graph.

Seeing Higgs tau tau would nail it down. Building a 250GeV linear collider and measuring the Higgs resonance width would *really* nail it down, eh? Let's do that.

And let's cut your funding to do it? When you're flipping burgers for a living, you can remind yourself that it's all worthwhile, because whilst the ILC still can't find any evidence for SUSY, they do have a bump on a graph.

Gotta go.

 

[Farsight]

I totally dismissed it because it was nothing to do with the question.

I answered your question here. That answer was everything to do with your question.

It was a repeat of you ignoring the Higgs mechanism. Then complaining about putting relativistic in front of QFT!

I didn't ignore your question. But you did totally dismiss my answer. I just missed your question because it was overtaken by events. It's been a busy thread.

Farsight: Is the Higgs mechanism a relativistic quantum field theory?
i.e. is it is based on special relativity and is thus consistent with E=mc^2.
First pointed out 1 November 2012

And the answer according to Wikipedia is : Yes!
Higgs mechanism

Wow - you really need to learn some physics, Farsight !
Without Lorentz invariance there is no SR and no E=mc²

Again, read my answer instead of dismissing it. Einstein said the mass of a body is a measure of its energy-content. Hence mass is another aspect of energy-momentum. The Higgs mechanism is at odds with that.

 

[Farsight]

Have to just add a voice in support of this comment. If you read Einstein's own book about his theory (aptly enough named "Relativity"), this is made clear. The basis of it lies in Lorentz invariance; that's the mathematical expression of his ideas on the constantsy of light speed. Thus, it's that invariance that leads to E=mc². It's absolutely the issue.

Note however that GR subsumes SR, and during the development of GR Einstein said this:

1911: If we call the velocity of light at the origin of co-ordinates cₒ, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = cₒ(1 + Φ/c²)
1912 : On the other hand I am of the view that the principle of the constancy of the velocity of light can be maintained only insofar as one restricts oneself to spatio-temporal regions of constant gravitational potential.
1913: I arrived at the result that the velocity of light is not to be regarded as independent of the gravitational potential. Thus the principle of the constancy of the velocity of light is incompatible with the equivalence hypothesis.
1915: the writer of these lines is of the opinion that the theory of relativity is still in need of generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned.
1916: In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity and with it the whole theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (e.g. of light).

Note that he said all this in German, and he didn't use the word velocity. The word he used was geschwindigkeit. That's speed. And c is a speed, not a velocity. The principle was the constant speed of light, not the vector-quantity. And we all know that the coordinate speed of light varies in a non-inertial reference frame. Such as in a gravitational field. The local speed of light is measured to be constant because the speed of clocks varies too. This is particularly noticeable for optical clocks.

 

[Farsight]

Oh dear: The fallacy of argument by authority that even cites an authority talking about somthing unrelated to the Higgs mechanism!

You asked me the question. I said I don't know, and offered a parallel. I'm not just arguing from Einstein's authority, I've explained the standing wave which adds mass to the system due to the symmetry between momentum and inertia. Did you miss it? Or did you dismiss that too?

to emphasis how bad this is :

• But see Woit's blog where he talks about SUSY as an unstoppable juggernaut, maybe the electron is something like that!
• But see Woit's blog where he talks about SUSY as an unstoppable juggernaut, maybe the neutrino is something like that!
• But see Woit's blog where he talks about SUSY as an unstoppable juggernaut, maybe the quarks are something like that!
• But see Woit's blog where he talks about SUSY as an unstoppable juggernaut, maybe the Z boson is something like that!
• But see Woit's blog where he talks about SUSY as an unstoppable juggernaut, maybe plate tectonics is something like that!
• But see Woit's blog where he talks about SUSY as an unstoppable juggernaut, maybe the theory of evolution is something like that!
• etc. etc. etc.

Get a grip, RC. You asked me a question, I responded in good faith.

Yes, that is what We (Apparently) Found the Higgs Boson. Now, Where the Heck Did It Come From? says.

Does not parse.

Re: maybe. I've not been saying that, and was surprised to see it in New Scientist. Then why did you cite an opinion piece in a science magazine rather than a scientific paper in a scientific journal. One that talks about black holes and so according to you must be wrong!

Because it contained quotes by CERN physicists that you ought to pay attention to.

You may have switched off the critical analysis part of your brain . Otherwise you would have asked yourself a simple question: Where is Matthew Chalmers' scientific paper that so easily invalidates the Higgs boson? And an even simpler question: Who is Matthew Chalmers? My guess - given his ignorance of how the Higgs boson gets its mass, a staff writer for New Scientist.

Oh right, you're going to dismiss reportage of what CERN physicists say because the report isn't a peer reviewed paper. Nice trick!

This is where the Higgs gets it mass from in a valid pop-science actual answer:
We (Apparently) Found the Higgs Boson. Now, Where the Heck Did It Come From?

And what's the answer? Let's have another look:

The answer may surprise you: The Higgs gives itself mass!

Why did physicists think up such a weird particle decades before they saw any evidence of it? Where did all these ideas come from? The answer is: pure mathematics!

Well whoopeedoo! That's all right then! Let's just suck that right up! And if anybody quotes Einstein at us and gives a careful explanation backed with hard scientific evidence, we can dismiss it as argument from authority and totally irrelevant!

Sigh. Gotta go.

 

[Hellbound]

Note however that GR subsumes SR, and during the development of GR Einstein said this:

1911: If we call the velocity of light at the origin of co-ordinates cₒ, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = cₒ(1 + Φ/c²)
1912 : On the other hand I am of the view that the principle of the constancy of the velocity of light can be maintained only insofar as one restricts oneself to spatio-temporal regions of constant gravitational potential.
1913: I arrived at the result that the velocity of light is not to be regarded as independent of the gravitational potential. Thus the principle of the constancy of the velocity of light is incompatible with the equivalence hypothesis.
1915: the writer of these lines is of the opinion that the theory of relativity is still in need of generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned.
1916: In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity and with it the whole theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (e.g. of light).

Note that he said all this in German, and he didn't use the word velocity. The word he used was geschwindigkeit. That's speed. And c is a speed, not a velocity. The principle was the constant speed of light, not the vector-quantity. And we all know that the coordinate speed of light varies in a non-inertial reference frame. Such as in a gravitational field. The local speed of light is measured to be constant because the speed of clocks varies too. This is particularly noticeable for optical clocks.

I'm sorry, can you explain what that has to do with my comment? I didn't mention velocity, I was discussing speed.

And just for fun, can you describe any actual, testible, functional difference between "the speed of light is measured to be constant" and "the speed of light is constant"?

 

[Tubbythin]

No, he isn't talking to me. I wonder, does Cuddles fight shy of talking to me because he's afraid I'll embarrass him with my understanding? OK, let's see what he's saying.

 

[Farsight]

...I can not see any circumstance where Fairsight's theories will play a significant role in that process.

I'm telling you about Einstein's theory, not mine. The mass of a body is a measure of its energy-content.