Now what about the supernova results? Four detectors were operating during the day of the SN 1987A event. Wikipedia tells us what they observed: (1) Kamiokande $11$ $\overline{\nu}$, IMB $8$ $\overline{\nu}$, Baksan $5$ $\overline{\nu}$ over $13$ seconds, three hours before the photons, (2) Mont Blanc $5$ $\nu$ (yes, neutrinos) over $7$ seconds, six hours before the photons. The Mont Blanc events are generally not thought to be correlated with SN 1987A. Let us now do the crazy theory thing and consider the possibility that astronomers do not understand supernovae. That is, from our Earth bound perspective we assume a simultaneity of both photon and neutrino output from the burst. The antineutrinos still travel at a speed very close to $c$, in order to arrive at roughly the same time as the photons (which has already been pointed out a gazillion times on the blogosphere), but we find that all $\nu$ and $\overline{\nu}$ are traveling at a speed greater than $c$.
Theoretical consistency then begs the question: why does the pink line drop to zero for large distances, in a vacuum, in the MeV range? Note that there are already several variables to play with here. First, assume that the MeV range is not the culprit (think MiniBooNE). Perhaps the pink line really is a local result, obtaining the maximum $\Delta v/c$, whereas the SN 1987A neutrinos are only tachyonic as they pass through (all very classical thinking) the stellar debris (someone already suggested this somewhere).
Many possibilities. Another crazy one is the following. What if the tachyonic neutrinos left the burst long after (as in years) the photons, so that $\Delta v/c$ matched the constant. Who are we to say that this is not the case in our frame.
I think the best reason for trusting the OPERA result is the poor understanding of relativity, even amongst theorists. Now, no doubt, many will foolishly rush for the foamy spacetime Lorentz violation bandwagon. Spacetime is not absolute.
ReplyDeleteThe last paragraph is not a joke about aliens with the technology to create supernovae.
ReplyDeleteLet us assume that in the local frame of SN1987A, there is a 3 hr difference between photon and antineutrino emission. These local conditions are then reproduced by the absorption of particles at the receiving end. This does not require an Earth (QG) frame to fix the 3 hours at SN1987A at 3 hours, which may well be years. This implies that there will always be a 3hr/6hr time lag, due to the details of the event, but that we cannot infer anything about the neutrino speed from this observation.
So, the naive supernova measurement is a red herring.
ReplyDeleteThe correct speed for an ultra low energy tachyon is probably $\infty$. Thus the pink curve asymptotes to the canonical $\Delta v/c$, but curves upwards at the left. As observed.
That was nice, Kea. Compare with black hole horizon, Minkowski lightcone, and Einstein. Maybe you will see the non-locality? These theoreticins are just fooling around. Einstein is still better in observing than they are :)
ReplyDeleteYes, never forget to take seriously what is observed, and only what is observed.
ReplyDelete"Let us assume that in the local frame of SN1987A, there is a 3 hr difference between photon and antineutrino emission. These local conditions are then reproduced by the absorption of particles at the receiving end. This does not require an Earth (QG) frame to fix the 3 hours at SN1987A at 3 hours, which may well be years. This implies that there will always be a 3hr/6hr time lag, due to the details of the event, but that we cannot infer anything about the neutrino speed from this observation."
ReplyDeleteI don't see any concept here, beyond total deconstruction of the usual space-time concepts via radical Humean skepticism.
What I mean by that:
Usually, in order to make any sort of prediction, any sort of induction, any sort of guess about the nature of anything, you need to make a few assumptions. But as Hume pointed out, correlation is not causation, no matter how great the correlation is, and one may always disown any causal interpretation and insist that anything at all might happen in the next moment.
In the passage I quoted, you seem to be saying, "Maybe there's a 3-hour time lag at the source (SN1987A), and maybe there's a 3-hour time lag at Earth, but there's no necessary connection between those two things, and no necessary implication for the velocities in between."
That is, I am unable to identify any contentful conception of space, time, matter, etc behind this statement of yours. It seems to be just a bare statement of possibility: "If we assume absolutely nothing about anything, then it is possible that there was a 3-hour time lag at the source, and a 3-hour time lag at Earth, and that the velocity in between was any value you like."
Well, Mitchell, you should read what I wrote again. I specifically said that local conditions were replicated at emitter and absorber. Hence, three hours is three hours. But as you may remember from high school, relativity allows time dilation, for suitable pairs of frames. Of course, I am also thinking about a quantum gravitational picture for how photons and neutrinos actually get from there to here, but then we have been doing that for years and what I just said was not inconsistent with it. It is HIGH time that stringers like you actually learned to take relativity seriously.
ReplyDelete"I specifically said that local conditions were replicated at emitter and absorber."
ReplyDeleteThat's exactly the problem. I have no idea what you mean by "local conditions". What conditions? Conditions of what?
"It is HIGH time that stringers like you actually learned to take relativity seriously."
What do you mean by relativity? Apparently something other than Lorentz invariance or local Lorentz invariance.
Ah, you have seen the non-locality :)
ReplyDeleteI was wondering if the neutrinos were actually produced at the site of the supernova. If the supernova produced some other light speed particle that decayed in the atmosphere of the earth, the neutrinos from that decay would be coincident in time with the light. Or at least offset by the delta for light versus that other light speed particle.
ReplyDeleteCarl, astrophysicist's had predictions about neutrino output from supernovae BEFORE the 1987A event. I think that counts for something.
ReplyDeletePhysicists think they understand supernovae enough to claim that SN indicate (the only indication) of cosmic 'acceleration'. Yet they haven't even figured out what powers the explosions. The stars that become supernovae would be likely locations of central Black Holes.
ReplyDeleteExactly, Louise. And I've been to enough astrophysics talks to know that quantum gravitational modeling of the system is still some way off.
ReplyDelete