Neutrinos supposedly have a non zero rest mass (the electron variety is currently hypothesized @ < 2.2eV), kaon & tau far higher.

Here's my burning issue;-

If the so-called neutrino surge detected from SN 1987a arrived @ approx' the same time as optical confirmation (some 18 hours later) ..... given that this supernova is around 51.4 thousand parsecs away, even a tiny rest mass would require near infinite energy to accelerate it to such speed.

Edit: Have I missed something obvious?
Confused1
Is the < 2.2eV rest or relativistic mass? What is the energy of the particle (if not < 2.2eV)? (We are preparing to have guests for dinner).
QUOTE (Confused1+May 13 2012, 10:06 AM)
Is the < 2.2eV rest or relativistic mass? What is the energy of the particle (if not < 2.2eV)? (We are preparing to have guests for dinner).

Good point, will dig deeper.
Robittybob1
QUOTE (Lady Elizabeth+May 13 2012, 09:37 AM)
Neutrinos supposedly have a non zero rest mass (the electron variety is currently hypothesized @ < 2.2eV), kaon & tau far higher.

Here's my burning issue;-

If the so-called neutrino surge detected from SN 1987a arrived @ approx' the same time as optical confirmation (some 18 hours later) ..... given that this supernova is around 51.4 thousand parsecs away, even a tiny rest mass would require near infinite energy to accelerate it to such speed.

Edit: Have I missed something obvious?

Not if it can use its own mass to cause the velocity, convert its rest mass to relativistic mass (KE plus momentum) regaining its mass when stopped.
So as it is moving it is virtually massless. (This is only an off the cuff suggestion).
Lasand
Old Winston on Russia:

"It is a riddle, wrapped in a mystery, inside an enigma."

Seems to fit the neutrino also.
QUOTE (Confused1+May 13 2012, 10:06 AM)
Is the < 2.2eV rest or relativistic mass? What is the energy of the particle (if not < 2.2eV)? (We are preparing to have guests for dinner).

C2, everything's still insanely fuzzy .... foggedly inapparent, with lashings of flavour changing, Majorana mechanism, mass eigenstates having values all over the shop. Essentially, more ludicrous than a long range UK weather forecast.

Edit;- help!
mathman
The neutrinos from a supernova have an almost clear path out, so their time of flight is not affected. Radiation has to go through a lot of matter, so it is impeded by reaction with the matter.

An everyday analogy: Neutrinos from the sun arrive at the earth a few minutes after they are born in the fusion reaction. On the other hand, radiation from fusion takes years to finally reach the surface and get out.

(Note - I am a little hazy as to the times involved, but the general idea is valid.)
QUOTE (mathman+May 13 2012, 08:34 PM)
The neutrinos from a supernova have an almost clear path out, so their time of flight is not affected. Radiation has to go through a lot of matter, so it is impeded by reaction with the matter.

An everyday analogy: Neutrinos from the sun arrive at the earth a few minutes after they are born in the fusion reaction. On the other hand, radiation from fusion takes years to finally reach the surface and get out.

(Note - I am a little hazy as to the times involved, but the general idea is valid.)

Yeah, I've already taken this into consideration; however, this absorption, re-emission jazz would only act to delay the initial photon burst for tens of hours @ most .... if neutrinos had any semblence of mass they'd arrive much, much later ... that's why I'm beginning to doubt this oscillation flavour concept stuff.

Extract from wiki

"The neutrino measurements allowed upper bounds on neutrino mass and charge, as well as the number of flavors of neutrinos and other properties.[6] For example, the data show that within 5% confidence, the rest mass of the electron neutrino is at most 16 eV. The data suggests that the total number of neutrino flavors is at most 8 but other observations and experiments give tighter estimates"

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