Dark Matter vs Dark Energy

In article ,
(Rob Oldershaw) writes:
Actually I am saying that the concept of magenetic monopoles is a
silly one, as those who study nature, rather than just squiggles on
paper, would be most likely to conclude.

Aren't you the one urging us to be open-minded? What makes you think
magnetic monopoles cannot exist? There certainly used to be lots of
smart people who thought they were a reasonable bet.

Questions for the experts:
1. Is there sound reason for ruling out the existence of magnetic
monopoles? I know of some upper limits on their abundance, but could
there be any at all?

2. Has there ever been a satisfactory explanation of the "Valentine's
Day Event?" Could it have been a genuine (but _very_ lucky!)
monopole detection?

[[Mod. note -- If it was a monopole detection, then we need to
somehow explain why/how none of the other monopole-detection
experiments have seen anything. I am not up to date with current
work in this area, but I had thought that other experiments now
have cumulative detection cross-sections that are much larger than
Cabrerra's up to the Valentine's-day event.
-- jt]]

--
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
(Please email your reply if you want to be sure I see it; include a
valid Reply-To address to receive an acknowledgement. Commercial
email may be sent to your ISP.)

In article ,
(Rob Oldershaw) writes:
Actually I am saying that the concept of magenetic monopoles is a
silly one, as those who study nature, rather than just squiggles on
paper, would be most likely to conclude.

Aren't you the one urging us to be open-minded? What makes you think
magnetic monopoles cannot exist? There certainly used to be lots of
smart people who thought they were a reasonable bet.

Questions for the experts:
1. Is there sound reason for ruling out the existence of magnetic
monopoles? I know of some upper limits on their abundance, but could
there be any at all?

2. Has there ever been a satisfactory explanation of the "Valentine's
Day Event?" Could it have been a genuine (but _very_ lucky!)
monopole detection?

[[Mod. note -- If it was a monopole detection, then we need to
somehow explain why/how none of the other monopole-detection
experiments have seen anything. I am not up to date with current
work in this area, but I had thought that other experiments now
have cumulative detection cross-sections that are much larger than
Cabrerra's up to the Valentine's-day event.
-- jt]]

--
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
(Please email your reply if you want to be sure I see it; include a
valid Reply-To address to receive an acknowledgement. Commercial
email may be sent to your ISP.)

[[Mod. note -- The existence or nonexistence of magnetic monopoles
seems to me to be more in sci.physics.research territory than
sci.astro.research, so I'm crossposting this to both newsgroups,
and rediercting followups to s.p.r. only. Unless it moves back into
s.a.r. territory, further discussion of this topic should be in s.p.r.
-- jt]]

Steve Willner wrote in message ...
In article ,
(Rob Oldershaw) writes:
Actually I am saying that the concept of magenetic monopoles is a
silly one, as those who study nature, rather than just squiggles on
paper, would be most likely to conclude.

Aren't you the one urging us to be open-minded?


Definitely, but should one be open-minded about the existence of
unicorns or "the face on Mars"? That's hyperbole, but one must have a
healthy skepticism to balance out the open-mindedness. Nothing I know
about NATURE supports the hypothesis of magnetic monopoles, and
decades of heroic searching have only produced negative results.
What's a poor boy to think? What does the man of wisdom (science)
conclude?


What makes you think magnetic monopoles cannot exist? There
certainly used to be lots of smart people who thought they
were a reasonable bet.


Sure, but then many "smart people" backed epicycles, phlogiston, etc.
"The authority of a thousand does not outweigh ..." - Galileo



Questions for the experts:

I gather that I am excluded from this set, so I won't... .


[[Mod. note -- There's a famous argument by (I think) Dirac
(it's summarized in Jackson's E&M textbook) that the existence of
even a single magnetic monopole in the universe would explain
(require for consistency) the quantization of electric charge.
-- jt]]

[[Mod. note -- The existence or nonexistence of magnetic monopoles
seems to me to be more in sci.physics.research territory than
sci.astro.research, so I'm crossposting this to both newsgroups,
and rediercting followups to s.p.r. only. Unless it moves back into
s.a.r. territory, further discussion of this topic should be in s.p.r.
-- jt]]

Steve Willner wrote in message ...
In article ,
(Rob Oldershaw) writes:
Actually I am saying that the concept of magenetic monopoles is a
silly one, as those who study nature, rather than just squiggles on
paper, would be most likely to conclude.

Aren't you the one urging us to be open-minded?


Definitely, but should one be open-minded about the existence of
unicorns or "the face on Mars"? That's hyperbole, but one must have a
healthy skepticism to balance out the open-mindedness. Nothing I know
about NATURE supports the hypothesis of magnetic monopoles, and
decades of heroic searching have only produced negative results.
What's a poor boy to think? What does the man of wisdom (science)
conclude?


What makes you think magnetic monopoles cannot exist? There
certainly used to be lots of smart people who thought they
were a reasonable bet.


Sure, but then many "smart people" backed epicycles, phlogiston, etc.
"The authority of a thousand does not outweigh ..." - Galileo



Questions for the experts:

I gather that I am excluded from this set, so I won't... .


[[Mod. note -- There's a famous argument by (I think) Dirac
(it's summarized in Jackson's E&M textbook) that the existence of
even a single magnetic monopole in the universe would explain
(require for consistency) the quantization of electric charge.
-- jt]]

Steve Willner wrote in message
...
In article ,
(Rob Oldershaw) writes:
Actually I am saying that the concept of magenetic monopoles is a
silly one, as those who study nature, rather than just squiggles on
paper, would be most likely to conclude.

Aren't you the one urging us to be open-minded? What makes you think
magnetic monopoles cannot exist? There certainly used to be lots of
smart people who thought they were a reasonable bet.

Questions for the experts:
1. Is there sound reason for ruling out the existence of magnetic
monopoles? I know of some upper limits on their abundance, but could
there be any at all?

Yes. The simplest is that magnetic monopoles would violate the physical
model that Maxwell used to derive 'Maxwell's equations.' (On Physical Lines
of Force, 1861)

2. Has there ever been a satisfactory explanation of the "Valentine's
Day Event?" Could it have been a genuine (but _very_ lucky!)
monopole detection?

I recall that it was attributed to a cosmic-ray event.

greywolf42
ubi dubium ibi libertas

Steve Willner wrote in message
...
In article ,
(Rob Oldershaw) writes:
Actually I am saying that the concept of magenetic monopoles is a
silly one, as those who study nature, rather than just squiggles on
paper, would be most likely to conclude.

Aren't you the one urging us to be open-minded? What makes you think
magnetic monopoles cannot exist? There certainly used to be lots of
smart people who thought they were a reasonable bet.

Questions for the experts:
1. Is there sound reason for ruling out the existence of magnetic
monopoles? I know of some upper limits on their abundance, but could
there be any at all?

Yes. The simplest is that magnetic monopoles would violate the physical
model that Maxwell used to derive 'Maxwell's equations.' (On Physical Lines
of Force, 1861)

2. Has there ever been a satisfactory explanation of the "Valentine's
Day Event?" Could it have been a genuine (but _very_ lucky!)
monopole detection?

I recall that it was attributed to a cosmic-ray event.

greywolf42
ubi dubium ibi libertas

On Thu, 21 Aug 2003 09:56:28 +0000, greywolf42 wrote:

Steve Willner wrote in message
...

Questions for the experts:
1. Is there sound reason for ruling out the existence of magnetic
monopoles? I know of some upper limits on their abundance, but could
there be any at all?

Yes. The simplest is that magnetic monopoles would violate the physical
model that Maxwell used to derive 'Maxwell's equations.' (On Physical Lines
of Force, 1861)

But they do not violate a number of more recent models. I think that's
the point. Maxwell's model may not allow monopoles, but they are
certainly allowed in many field theory models.

Maxwell's model isn't the last word in electrodynamics, there's QED and
the Standard Model. Neither of those make any use of Maxwell's model
(though the reproduce Maxwell's equations in the correct limit).

As for ruling out monopoles or not, there's plently of beyond the standard
model theories that predict them. So at this point I wouldn't rule them
out completly. And I certainly wouldn't rule them out based on a 150 year
old model.

Matthew Nobes

On Thu, 21 Aug 2003 09:56:28 +0000, greywolf42 wrote:

Steve Willner wrote in message
...

Questions for the experts:
1. Is there sound reason for ruling out the existence of magnetic
monopoles? I know of some upper limits on their abundance, but could
there be any at all?

Yes. The simplest is that magnetic monopoles would violate the physical
model that Maxwell used to derive 'Maxwell's equations.' (On Physical Lines
of Force, 1861)

But they do not violate a number of more recent models. I think that's
the point. Maxwell's model may not allow monopoles, but they are
certainly allowed in many field theory models.

Maxwell's model isn't the last word in electrodynamics, there's QED and
the Standard Model. Neither of those make any use of Maxwell's model
(though the reproduce Maxwell's equations in the correct limit).

As for ruling out monopoles or not, there's plently of beyond the standard
model theories that predict them. So at this point I wouldn't rule them
out completly. And I certainly wouldn't rule them out based on a 150 year
old model.

Matthew Nobes

In article ,
(Jeffery) writes:

"...The most interesting feature of the Standard Model is that it is based
on symmetry. ..."

"Each of these three symmetries {strong, weak and electromagnetic force} is
simple and elegant. However, the most controversial aspect of the Standard
Model is that it 'unifies' the three fundamental forces by simply splicing
all three symmetries into one large symmetry, SU(3) x SU(2) x U(1), which is
just the product of the symmetries of the individual forces. ..."

"(The Standard Model) is very ugly because it crudely splices three very
different interactions together. Personally, I think that the Standard
Model can be compared to crossing three entirely dissimilar types of
animals, such as a mule, an elephant, and a whale. In fact, it is so ugly
and contrived that even its creators are a bit embarrassed. They are the
first to apologize for its shortcomings and admit that it cannot be the
final theory." {i.e. It cannot be physically 'correct.'}

None of the things you listed are in anyway a criticism of the
Standard Model? The worst you can say about it is that some guy thinks
it's ugly? I don't think it's "ugly".

I find myself agreeing with this criticism that the standard model is
ugly. I don't have my copy of "Surely You're Joking, Mr. Feynman"
nearby, otherwise I would give the exact reference. There is a story
about someone interviewing Feynman, and the standard model comes up.
Feynman, also perceiving the ugliness, shouts mockingly "SU(3) x SU(2) x
U(1), bla bla bla" at which point Murray Gell-Mann sticks his head out
of his office and says to the interviewer "I see you've met Dick".

To me, Maxwell's unification of electricity and magnetism is a REAL
unification, somehow qualitatively better than that of the standard
model. In general, a unification energy scale is expressed which is the
energy at which the coupling constants are all equal. But how do we
know for sure if the curves of coupling constants vs. energy really do
all meet at one point? Is there any reason, other than hope of
"unification", to believe this?

And what about gravity? Sure, there are some areas where QM and GR
aren't compatible, and quantum gravity will be needed. But perhaps this
quantum gravity will not be a "unification" of gravity with the other
interactions.

In article ,
(Jeffery) writes:

"...The most interesting feature of the Standard Model is that it is based
on symmetry. ..."

"Each of these three symmetries {strong, weak and electromagnetic force} is
simple and elegant. However, the most controversial aspect of the Standard
Model is that it 'unifies' the three fundamental forces by simply splicing
all three symmetries into one large symmetry, SU(3) x SU(2) x U(1), which is
just the product of the symmetries of the individual forces. ..."

"(The Standard Model) is very ugly because it crudely splices three very
different interactions together. Personally, I think that the Standard
Model can be compared to crossing three entirely dissimilar types of
animals, such as a mule, an elephant, and a whale. In fact, it is so ugly
and contrived that even its creators are a bit embarrassed. They are the
first to apologize for its shortcomings and admit that it cannot be the
final theory." {i.e. It cannot be physically 'correct.'}

None of the things you listed are in anyway a criticism of the
Standard Model? The worst you can say about it is that some guy thinks
it's ugly? I don't think it's "ugly".

I find myself agreeing with this criticism that the standard model is
ugly. I don't have my copy of "Surely You're Joking, Mr. Feynman"
nearby, otherwise I would give the exact reference. There is a story
about someone interviewing Feynman, and the standard model comes up.
Feynman, also perceiving the ugliness, shouts mockingly "SU(3) x SU(2) x
U(1), bla bla bla" at which point Murray Gell-Mann sticks his head out
of his office and says to the interviewer "I see you've met Dick".

To me, Maxwell's unification of electricity and magnetism is a REAL
unification, somehow qualitatively better than that of the standard
model. In general, a unification energy scale is expressed which is the
energy at which the coupling constants are all equal. But how do we
know for sure if the curves of coupling constants vs. energy really do
all meet at one point? Is there any reason, other than hope of
"unification", to believe this?

And what about gravity? Sure, there are some areas where QM and GR
aren't compatible, and quantum gravity will be needed. But perhaps this
quantum gravity will not be a "unification" of gravity with the other
interactions.