Could Neutrinos be Gravitons?

[Carlington]

I had another idea the other night. Sometimes these ideas I have help me to better understand the concepts I'm learning about, for example realising that within a transverse wave there lies a longitudinal wave, and that this is how we draw our amplitude vs. time graphs for sound waves. Sometimes these ideas are complete cock-and-bull, meaningless and irrational, and they only make sense at the time. Like that one time that I proved dividing 6*pi by 6 results in pi. This most recent of my ideas will probably fall into the latter category, but I want the opinions of you xkcdians, the ones I respect most.

So it goes like this: neutrinos don't¹ affect anything on a quantum scale. They have no mass¹ or anything of the like. Possibly trillions of neutrinos generated by the sun pass through the Earth all the time, with seemingly no noticeable effect.
Gravity doesn't affect anything on a quantum scale. It doesn't affect any of the quanta, i.e. hadrons, leptons, bosons.

I drew a similarity where there may in fact be none to be drawn and made the seemingly logical conclusion that neutrinos may, in fact, be the force-carriers for gravity. Now, for that to be the case, every body must generate neutrinos, and I realise this. What would be the most simple way to verify this theory? Test if the Earth itself generates neutrinos. Why can't we do this? Because of the sheer number of solar neutrinos passing through the experiment. They would generate so much interference as to render our tests useless. So how can we verify this? Well, I don't really know. That's why I'm adivisng myself, and everyone else, to take my ideas with a grain of salt. The real reason I posted here was to get thoughts and intelligent discussion on the matter. Can you tell me if it's possible that I'm right. If so, why? How about if I'm wrong? Can anybody reasonably prove that I'm wrong? Can anybody add anything to this idea, or point out any flaws in my thinking? Nobody else that I know can provide the kind of insight I see from the prople here all the time.


¹ Approximately, for all intents and purposes.

[gmalivuk]

No.

Neutrinos are actually reasonably well understood, and are generated in nuclear reactions. (Solar neutrino output varies noticeably, for example, despite the sun's mass having no such variation) Gravity, on the other hand, is generated by all matter.

[Tass]

Short answer: No.

Neutrinos does interact, but only very weakly through the weak force. Gravitons don't even do that. Neutrinos are fermions, gravitons would be bosons. Neutrinos are a well understood and integral part of the standard model of physics (and without the standard model you wouldn't even be looking for a "force carrier").

Compared to gravitons, neutrinos are strongly interacting particles. We are building huge kilometer long instruments capable of detecting deflections of a fraction of a proton diameter and they are just barely able to detect gravity waves. Detecting the quantization of said waves are so far beyond or capabilities at the moment. Compared to this detecting neutrinos are easy. Neutrinos do once in a while knock an electron out of its atom after all.

In short they are different particles, with very different characteristics despite superficial similarities, both with an extensive and rigorously tested theoretical framework behind them. Having neutrinos be gravitons would be like having photons being a variety of electrons, you'd need to rewrite all of physics.

Gravity doesn't affect anything on a quantum scale. It doesn't affect any of the quanta, i.e. hadrons, leptons, bosons.

Of course it does. It is just terribly weak and extremely homogenous every where except near black holes and at the beginning of the universe.

[JWalker]

Unfortunately no, neutrinos cannot be gravitons.

We know that neutrinos have spin 1/2, so they are fermions. We also strongly suspect that they do in fact have mass. Both of these things make it impossible for a neutrino to be the force carrier of gravity. If the graviton exists, it would have to be massless in order to explain the long range of the gravitational force (if it was massive, the gravitational force would decrease with distance much faster than 1/r^2), and it also has to be a spin 2 boson, as any lower spin boson or any fermion would not result in massive particles experiencing an attractive force as well as massive particles and antiparticles likewise experiencing an attractive force.

[Sir_Elderberry]

within a transverse wave there lies a longitudinal wave, and that this is how we draw our amplitude vs. time graphs for sound waves

Not to get off topics, but what do you mean by this? A transverse wave is one in which some vector quantity (position, electric field, etc) varies perpendicularly to the direction of energy travel. A logitudinal wave is one in which the direction of that variation is parallel to the direction of travel--air molecules move back and forth, etc. We draw "amplitude" for sound waves, yes, but it doesn't relate to a position, just like how the arrows we draw for an EM wave's electric field don't actually take up the space they do on our diagram.

[scarecrovv]

What would be the most simple way to verify this theory? Test if the Earth itself generates neutrinos. Why can't we do this? Because of the sheer number of solar neutrinos passing through the experiment. They would generate so much interference as to render our tests useless.

I don't know jack shit about quantum physics either, so your idea sounded at least plausible. However, I thought through this statement a little more carefully, and you may (or may not) be interested in the results:

Suppose neutrinos are gravitons. In that case, neutrino flux through the local area from a given source must be proportional to the strength of the gravitational field from that source. The earth's gravitational field strength at the surface is 9.8m/s/s, as we all know. Typing "(G * mass of sun)/(1 AU)^2" (sans quotes) into Google's search bar yields .0059 m/s/s. Therefore, neutrinos from the Earth should massively dwarf neutrinos from the Sun. However, this is not the case, so neutrinos are not gravitons.

Good try though, keep thinking.

[Carlington]

At least I was shot down pleasantly.
Thanks for explaining why I was wrong, though. It makes it a lot easier to swallow when there's at least a reason that I was wrong, unlike the "You're wrong because you are" I so often get from teachers.

[ian]

although its been disproven already, force carriers don't have anti-particles. neutrions do.

[SU3SU2U1]

although its been disproven already, force carriers don't have anti-particles. neutrions do.

The W+ anti particle is the W-.

[ian]

oh i derped.

though not having charge, a graviton wouldn't have an anti-particle?

[doogly]

The photon is its own antiparticle. Graviton is the same.
http://sci.tech-archive.net/Archive/sci ... 02258.html
Baez is a beast.

[ian]

well a neutrino isn't, so uh.....i win?

[Carlington]

What would be the most simple way to verify this theory? Test if the Earth itself generates neutrinos. Why can't we do this? Because of the sheer number of solar neutrinos passing through the experiment. They would generate so much interference as to render our tests useless.

I don't know jack shit about quantum physics either, so your idea sounded at least plausible. However, I thought through this statement a little more carefully, and you may (or may not) be interested in the results:

Suppose neutrinos are gravitons. In that case, neutrino flux through the local area from a given source must be proportional to the strength of the gravitational field from that source. The earth's gravitational field strength at the surface is 9.8m/s/s, as we all know. Typing "(G * mass of sun)/(1 AU)^2" (sans quotes) into Google's search bar yields .0059 m/s/s. Therefore, neutrinos from the Earth should massively dwarf neutrinos from the Sun. However, this is not the case, so neutrinos are not gravitons.

Good try though, keep thinking.

Wait on, I think you misunderstood me a bit, or you made a mistake. Or I misunderstood you, it could really go either way. You've gone (G*mass of sun)/(1 AU)^2 = .0059 m/s^2
In other words: F/d^2 = a
Now, checking that with units, we get: kg*m*s^(-2)*m^(-2) = m*s^(-2)
Simplifying: kg*m^(-1)*s^(-2) = m*s^(-2)

and that's not a true statement. I don't doubt that I'm incorrect on other fronts, i.e. I was incorrect in my assumptions that neutrinos have no mass and don't interact, as gmalivuk, Tass and JWalker explained, but I thought I'd point out that your logic is a touch flawed, scarecrovv.

within a transverse wave there lies a longitudinal wave, and that this is how we draw our amplitude vs. time graphs for sound waves

Not to get off topics, but what do you mean by this? ...

Well, it only really applies to standing waves now that I think about it.




In that (shoddy, 30-second, MSPaint ) diagram, A is a node, B and C are the maximum and zero amplitudes of the antinode.
As the shape of the wave rotates from AB to AC, our approximaton shows us that the distance between these two points fluctuates periodically with the motion of the transverse wave. Remembering that none of the individual particles in a transverse wave actually move in the direction of propagation, this change in distance between the two points must therefore represent compressions and rarefactions. Knowing as we do that compressions and rarefactions mean longitudinal wave, we can see that within this transverse standing wave there lies a longitudinal wave. According to my physics teacher, (who has lied to make the answers to my questions easier before) we use the reverse of this process to graphicaly represent the amplitude over time of a compressional wave, usually a sound wave.

[doogly]

That wasn't F/d^2, that was F/m. Your units for the constant G are off.

[Carlington]

Unless AU^2 has become a unit for mass since the last time I checked? AU, or Astronomical Unit is the distance between the Earth and Sol? O.o

[doogly]

oh, so you thought G*mass of the sun was a force?
Ah, you thought that because you thought G=9.8 m/s^2 ! That's g. Big G is the universal gravitational constant. Little g is the value of the gravitational field at the surface of the earth.

g = G * (mass of earth) / (radius of earth)^2

[Antimony-120]

Unless AU^2 has become a unit for mass since the last time I checked? AU, or Astronomical Unit is the distance between the Earth and Sol? O.o

Clearly they meant Amps times potential energy squared.

[Carlington]

oh, so you thought G*mass of the sun was a force?
Ah, you thought that because you thought G=9.8 m/s^2 ! That's g. Big G is the universal gravitational constant. Little g is the value of the gravitational field at the surface of the earth.

g = G * (mass of earth) / (radius of earth)^2

Oh! Well, I'll be blowed, I stand very thoroughly corrected. My apologies to you, good sir.
I should have known better than to doubt a forumite; they're a brainy bunch, or so I've heard.

[gmalivuk]

Not only did you doubt a forumite, you also doubted Google's dimensional calculations!

[Carlington]

Forgive me, I beg of you! I was young and foolish!
But in all seriousness, I am in a state of disbelief over the fact that I managed to doubt an xkcdian and the Great Leader Google in one fell swoop. Chalk it up to the fact that it's 3am and I haven't got any caffeine to hand.

[SU3SU2U1]

well a neutrino isn't, so uh.....i win?

Actually, if neutrinos are majorana, they are their own anti-particles. There are experimentalists looking for this right now (see, for instance, neutrinoless double-beta-decay.

[Timtu]

I'll tack this on the end...

The fact that neutrinos likely have mass is important because gravitational waves can be shown to travel at something close to the speed of light.

om nom nom nom knowledge

[Carlington]

"Something close to the speed of light"?
That infers, in my mind, that we don't know whether gravity waves/gravitons have mass or not?

Also, I just realised that neutrinos are not bosons and of course they have mass, etc. Feelin' like a bit of a doopy now.

[doogly]

According to GR gravity is massless. The bounds on whether this is actually true all the way down through the quantum theory is less tightly bounded than with photons, but still, I wouldn't be putting money on it.

[Novae D'Arx]

Gravity is a weird one. We've been trying to find the elusive graviton for a long time, and there's a lot of doubt as to whether it's really a "thing" or not.

My personal bet is that a lot of our jiggering with fields and virtual particles, etc. are going to, in the end, be explained much better with the interactions between Calabi-Yau manifolds in multidimensional space. It seems like we're slooowly groping in that direction, though nobody really wants to say that except the string theorists... But who the hell in their right mind listens to a string theorist, except maybe desperate hippies in search of a cheap way to make their brains do a triple lutz and a salchow or two?

So, um, yeah. I think we're in for an interesting millennium. Once we get done working out the retardedly complex mathematics and do some more work (hopefully the LHC will provide enough info to narrow down the candidates) on the C-Y geometries, we miiiight just work out why force fields act so fookin' strange and are so resistant to common sense visualization. I mean, even the theories state that they basically have to imagine a particle is there, but really isn't, to be able to explain how the various vector fields act. I think actually being able to explain, rather than describe, these fields would go a long way towards dealing with our groping physics models.

/Cue the angry, violent physicists coming for the inevitable beatdown.
//Oh, God - they brought pitchforks AND torches... HIDE ME

[Carlington]

With some clever use of Google-Fu, I found out what a Calabi-Yau manifold is. Sorta. I'm not quite there with some of the heavier terminology and concepts, but I think I have a semi-reasonable grasp on what you're saying. I'm not exactly sure how one would apply that the the problem at hand, but I'm sure I'm missing something fairly vital there anyway.

[doogly]

They're pretty tricky, and fairly important in string theory. I think the above poster was just sputtering some things of little substance hoping that people will come with pitchforks so there can be shouting. I wouldn't worry about it.

[Carlington]

There's always one, isn't there? Yes, debate and discussion are important in the process of scientific progress, but that doesn't debate will directly cause progress. We shouldn't stir it up unless necessary, really.

[Robert rox]

Here is the thing. Neutrinos were just recently tested and their "speed" is faster than light by 30 nanoseconds. If they have mass and photons don't yet they are impossibly faster then how is that true? Well the explanation is simple. Neutrinos can bend space and time like gravitons can jump from dementions so it looks like it is faster than the speed of light. Perhaps neutrinos are made of gravitons (looped strings that have the weak force of gravity). Or so it seems. A theory suggests that gravity is just as strong as electromagnetism but just seems weaker. IMeaning that the strong and weak nuclear and the electro magnetic forces, in the string theory, suggest that they are tied down to a membrane, a stretched out widened string with it's own space-time dimension, i.e. 3d. The three forces are tied down to the membrane while the graviton (gravity string) is free to move from dimension to dimension (membrane to membrane). This definitely works with quantum mechanics so gravity does play a part in it. It was long argued that gravity had no relation with quantum mechanics because the math didn't work right. But with this theory it most definitely can. Infact there is also a theory that our universe is in a giant mbrane (the math works for this concept) and the Big Bang was another free floating universe (membrane) that hit ours causing a burst of energy creating our universe. Of coarse we don't know what happens when two membranes hit each other but this theory might explain everything from the Big Bang to multiverses to atoms and quantum mechanics. The answer in in the strings.

[yurell]

Here is the thing. Neutrinos were just recently tested and their "speed" is faster than light by 30 nanoseconds.

That result was demonstrated to be the result of faulty wiring (i.e. experimental error), not superluminal neutrinos.

[Robert rox]

Ok there was faulty wiring but all of the results afterwards concluded that neutrinos goes the same speed as light which is interesting that a particle with mass can go as fast as a particle with out mass. So the warp theory could still be relevant.

[gmalivuk]

No, the consensus is still that neutrinos travel slower than light, as predicted.

[mfb]

Ok there was faulty wiring but all of the results afterwards concluded that neutrinos goes the same speed as light which is interesting that a particle with mass can go as fast as a particle with out mass. So the warp theory could still be relevant.

The expected speed difference to light is so extremely tiny it is impossible to measure it (with all exisiting and even proposed experiments). The experimental values are in agreement with this prediction.
Your previous post is not a theory, it is a collection of buzzwords.

[Ixtellor]

Isn't there a theory about tiny 'particles' that can evolve based on the amount of mass in the vicinity?
(I say particles because I don't have the vocab like bosons, etc)

Hence, could a particle be both at different times?

[doogly]

No, that is not a thing.

[thoughtfully]

It resembles a bit the idea that at high energies, forces unify and their bosons become indistinguishable. Perhaps morphing among themselves at a whim much as massive neutrinos do, with a bit of hand-wavy layperson-speak to help them along.

[doogly]

But neutrinos are not bosons, so this would seem to be a double stretch even by those standards, no?

[Ixtellor]

No, that is not a thing.

I found what I was thinking of.
http://en.wikipedia.org/wiki/Chameleon_particle

The "chameleon" is a postulated scalar particle with a non-linear self-interaction that gives the particle an effective mass that depends on its environment: the presence of other fields.[1] It would have a small mass in much of intergalactic space, but a large mass in terrestrial experiments, making it difficult to detect. The chameleon is a possible candidate for dark energy and dark matter, and may contribute to cosmic inflation.

Yea the more I read the less I understand... I should be quiet now.