Arnold Neumaier
Jul30-04, 12:55 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nPerfectly Innocent wrote:\n> daniel@elit.net (Daniel Elander) wrote in message news:<37d84b42.040728=\n1407.1fa13104@posting.goog le.com>...\n>=20\n>>So tell me why neutrinos from supernova explosions arrive after the lig=\nht does.\n>=20\n>=20\n> I\'ve read that neutrinos from Supernova 1987A were observed to arrive\n> 18 hours before the photons.\n> http://www.npl.washington.edu/AV/altvw54.html\n> The same link mentions the difficulty in detecting low energy solar\n> neutrinos. If neutrinos are tachyonic, then the slowest moving\n> tachyons have the greatest energy. That could explain why detectable\n> neutrinos are only noticed at speeds comparatively equal to the speed\n> of light.\n\nNeutrinos are very unlikely to be tachyons, since the\nlatter produce Cerenkov radiation which has never been observed.\n(However, Cerenkov radiation is indeed observed when fast particles\nenter a dense medium in which the speed of light is smaller than\nthe particle\'s speed. Relativitly only demands that no particle with\nreal mass is faster than the speed of light in vacuum.)\n\nThe interest stopped around 1980, when it was clear that\nthe QFT of tachyons would be very different from standard QFT,\nand that experiment didn\'t demand their existence.\n\nIn fact, the theory of symmetry breaking demands that tachyons do\n_not_ exist: When a relativistic field theory is deformed in a way\nthat the square of the mass (pole of the S-matrix) of some physical\nparticle would cross zero, the old physical vacuum becomes unstable and\ninduces a phase transition to a new physical vacuum in which all particle=\ns\nhave real nonnegative mass. This is believed to be the cause of inflation=\n\nin the early universe. (Of course, the exact mechanism is not known\nsince it would require a nonperturbative definition of QFT.\nBut classical and semiclassical computations strongly suggest the\ncorrectness of this picture.)\n\nhttp://www.weeklyscientist.com/ws/articles/tachyons.htm\nspeculates about connections between tachyons and inflation,\nbut has some links with further useful information.\n\nBelow are some references about tachyons, for those interested;\nthe more important papers are marked by an asterisk.\n\n\nArnold Neumaier\n\n\n=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=\n=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D\n\n* G. Feinberg,\nPossibility of Faster-Than-Light Particles,\nPhys. Rev. 159, 1089 (1967).\n\nJ. Dhar and E. C. G. Sudarshan,\nQuantum Field Theory of Interacting Tachyons,\nPhys. Rev. 174, 1808-1815 (1968)\n\nM. Gl=FCck,\nNote on Causal Tachyon Fields,\nPhys. Rev. 183, 1514 (1969).\n\nD. G. Boulware,\nUnitarity and Interacting Tachyons,\nPhys. Rev. D 1, 2426 (1970).\n\n* B. Schroer,\nQuantization of m2<0 Field Equations,\nPhys. Rev. D 3, 1764 (1971).\n\nG. Feinberg\nLorentz invariance of tachyon theories\nPhys. Rev. D 17, 1651 (1978)\n\nC. Schwartz\nSome improvements in the theory of faster-than-light particles\nPhys. Rev. D 25, 356 (1982)\n\nSM. B. Davis, M. N. Kreisler, and T. Alv=E4ger\nSearch for Faster-Than-Light Particles\nPhys. Rev. 183, 1132 (1969)\n\n* L. W. Jones\nA review of quark search experiments\nRev. Mod. Phys. 49, 717 (1977)\n[Section IIIG is relevant.]\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Perfectly Innocent wrote:
> daniel@elit.net (Daniel Elander) wrote in message news:<37d84b42.040728=
1407.1fa13104@posting.google.com>...
>=20
>>So tell me why neutrinos from supernova explosions arrive after the lig=
ht does.
>=20>=20
> I've read that neutrinos from Supernova 1987A were observed to arrive
> 18 hours before the photons.
> http://www.npl.washington.edu/AV/altvw54.html
> The same link mentions the difficulty in detecting low energy solar
> neutrinos. If neutrinos are tachyonic, then the slowest moving
> tachyons have the greatest energy. That could explain why detectable
> neutrinos are only noticed at speeds comparatively equal to the speed
> of light.
Neutrinos are very unlikely to be tachyons, since the
latter produce Cerenkov radiation which has never been observed.
(However, Cerenkov radiation is indeed observed when fast particles
enter a dense medium in which the speed of light is smaller than
the particle's speed. Relativitly only demands that no particle with
real mass is faster than the speed of light in vacuum.)
The interest stopped around 1980, when it was clear that
the QFT of tachyons would be very different from standard QFT,
and that experiment didn't demand their existence.
In fact, the theory of symmetry breaking demands that tachyons do
_not_ exist: When a relativistic field theory is deformed in a way
that the square of the mass (pole of the S-matrix) of some physical
particle would cross zero, the old physical vacuum becomes unstable and
induces a phase transition to a new physical vacuum in which all particle=
s
have real nonnegative mass. This is believed to be the cause of inflation=
in the early universe. (Of course, the exact mechanism is not known
since it would require a nonperturbative definition of QFT.
But classical and semiclassical computations strongly suggest the
correctness of this picture.)
http://www.weeklyscientist.com/ws/articles/tachyons.htm
speculates about connections between tachyons and inflation,
but has some links with further useful information.
Below are some references about tachyons, for those interested;
the more important papers are marked by an asterisk.
Arnold Neumaier
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D==3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
* G. Feinberg,
Possibility of Faster-Than-Light Particles,
Phys. Rev. 159, 1089 (1967).
J. Dhar and E. C. G. Sudarshan,
Quantum Field Theory of Interacting Tachyons,
Phys. Rev. 174, 1808-1815 (1968)
M. Gl=FCck,
Note on Causal Tachyon Fields,
Phys. Rev. 183, 1514 (1969).
D. G. Boulware,
Unitarity and Interacting Tachyons,
Phys. Rev. D 1, 2426 (1970).
* B. Schroer,
Quantization of m2<0 Field Equations,
Phys. Rev. D 3, 1764 (1971).
G. Feinberg
Lorentz invariance of tachyon theories
Phys. Rev. D 17, 1651 (1978)
C. Schwartz
Some improvements in the theory of faster-than-light particles
Phys. Rev. D 25, 356 (1982)
SM. B. Davis, M. N. Kreisler, and T. Alv=E4ger
Search for Faster-Than-Light Particles
Phys. Rev. 183, 1132 (1969)
* L. W. Jones
A review of quark search experiments
Rev. Mod. Phys. 49, 717 (1977)
[Section IIIG is relevant.]
> daniel@elit.net (Daniel Elander) wrote in message news:<37d84b42.040728=
1407.1fa13104@posting.google.com>...
>=20
>>So tell me why neutrinos from supernova explosions arrive after the lig=
ht does.
>=20>=20
> I've read that neutrinos from Supernova 1987A were observed to arrive
> 18 hours before the photons.
> http://www.npl.washington.edu/AV/altvw54.html
> The same link mentions the difficulty in detecting low energy solar
> neutrinos. If neutrinos are tachyonic, then the slowest moving
> tachyons have the greatest energy. That could explain why detectable
> neutrinos are only noticed at speeds comparatively equal to the speed
> of light.
Neutrinos are very unlikely to be tachyons, since the
latter produce Cerenkov radiation which has never been observed.
(However, Cerenkov radiation is indeed observed when fast particles
enter a dense medium in which the speed of light is smaller than
the particle's speed. Relativitly only demands that no particle with
real mass is faster than the speed of light in vacuum.)
The interest stopped around 1980, when it was clear that
the QFT of tachyons would be very different from standard QFT,
and that experiment didn't demand their existence.
In fact, the theory of symmetry breaking demands that tachyons do
_not_ exist: When a relativistic field theory is deformed in a way
that the square of the mass (pole of the S-matrix) of some physical
particle would cross zero, the old physical vacuum becomes unstable and
induces a phase transition to a new physical vacuum in which all particle=
s
have real nonnegative mass. This is believed to be the cause of inflation=
in the early universe. (Of course, the exact mechanism is not known
since it would require a nonperturbative definition of QFT.
But classical and semiclassical computations strongly suggest the
correctness of this picture.)
http://www.weeklyscientist.com/ws/articles/tachyons.htm
speculates about connections between tachyons and inflation,
but has some links with further useful information.
Below are some references about tachyons, for those interested;
the more important papers are marked by an asterisk.
Arnold Neumaier
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D==3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
* G. Feinberg,
Possibility of Faster-Than-Light Particles,
Phys. Rev. 159, 1089 (1967).
J. Dhar and E. C. G. Sudarshan,
Quantum Field Theory of Interacting Tachyons,
Phys. Rev. 174, 1808-1815 (1968)
M. Gl=FCck,
Note on Causal Tachyon Fields,
Phys. Rev. 183, 1514 (1969).
D. G. Boulware,
Unitarity and Interacting Tachyons,
Phys. Rev. D 1, 2426 (1970).
* B. Schroer,
Quantization of m2<0 Field Equations,
Phys. Rev. D 3, 1764 (1971).
G. Feinberg
Lorentz invariance of tachyon theories
Phys. Rev. D 17, 1651 (1978)
C. Schwartz
Some improvements in the theory of faster-than-light particles
Phys. Rev. D 25, 356 (1982)
SM. B. Davis, M. N. Kreisler, and T. Alv=E4ger
Search for Faster-Than-Light Particles
Phys. Rev. 183, 1132 (1969)
* L. W. Jones
A review of quark search experiments
Rev. Mod. Phys. 49, 717 (1977)
[Section IIIG is relevant.]