Re: Consistancy of the speed of light.

"Spaceman" <Realspace@xxxxxxxxxxx> wrote in message news:qMidnS86Eac7V3veRVn-pg@xxxxxxxxxxxxxx

"Greg Neill" <gneillREM@xxxxxxxxxxxxxxxxxx> wrote in message
news:kpzFf.7161$1e5.154111@xxxxxxxxxxxxxxxxxxxxxxxx
| You're being foolish again, James. The speeds of
| these things are such that no deviations from
| a straight line path will occur. These things
| aren't floating down through honey you know.
| They're moving like a bullet through a vacuum.

No,
they are moving like a bunch of electrons through electrons and atoms
and molecules etc..
They might be fast, but they are not immune to what they are traveling
through and if they act anything like light, they should also be curving a
bit
from gravity.

This is where your lack of math skills lets you down,
otherwise you wouldn't make such a statement without
checking first. To them the entire atmosphere is
essentially like a hard vacuum. These things have
no measurable size (they're just like really heavy
electrons).

Since they're moving essentially straight downwards,
any change in velocity due to gravity will be in
that direction too.

Light doesn't deviate significantly from a straight
line path in traversing a piddly field like Earth's,
either.


| Too fast and too heavy to deviate. Gravity acts on them
| for a few tens of microseconds while they descend. Muons
| have no stong interaction properties and are too massive
| to be significantly deflected by atomic electric fields
| that they encounter.

Who is saying atomic electric fields?
I am talking about the Earths static field.
there are tons of electrons out there that have no
atomic connections.

The vast majority of atmopheric molecules are neutral.
Any electron trying to muscle a muon is going to be
brushed aside like it wasn't there. The muon has a
rest mass of about 207 times that of an electron, and
these things are coming in hot and heavy.

James, stop your handwaving and run some numbers.

and still you are not following one specific one
so you can not just say such without actual physical
proof if you wish to call such "physical" proof.

Why do you want to follow one? I have to ask myself,
why is James harping on this particular idea, and the
reason I come up with is, he's got nothing else.
Rather than accept the facts gracefully, he will
niggle and whinge on over some irrelevant but
impossible to satisfy item.

James. Unless you can show how it is required that
some particular muon be followed all the way from
top to bottom rather than simply measuring the flux
of muons at various heights to determing decay rate,
(and you must show mathematically that different
results will be found), I'm declaring this point
closed.

| What pressure can a muon feel? It's much smaller
| than any atom. As far as it's concerned, *everywhere*
| is a vacuum. Or are you going to invoke some
| mytical properties here?

Oh, ya,
I forgot, you think pressure does not occur in small stuff
because we can't measure it.
fine, I will give ya that one.
:)


| As I said, there's no need. We know where they are
| generated (at about 9000m altitude) and that they
| have specific decay rates, interaction cross sections,
| and so forth. We know how much energy they have when
| they do make it to ground level (that is, we know their
| velocities).

There is a need to do such to call it physical proof.
To say one muon does such and such and it is proven
because we see this at start and this at end, (without
following it through the entire path it takes)
is not physical proof.
It is merely abstract proof.

It is not abstract proof (whatever that is). It may
be slightly indirect in nature, but it is damned solid
and is as close to direct evidence as you can get.
We know the source of the particles, we know how and
where they are generated, we know their characteristics
well enough to predict their interaction cross sections
and mean free path length so that we can make firm
predictions about the mumbers that should make it to
ground level.

I suppose that you discount wind tunnel experiments
because we don't follow the trajectory of every air
molecule? Or are you willing to concede that air has
certain predictable qualities in bulk?




| They have a rest frame decay halflife of about 1.4
| microseconds. Travel time according to our clocks
| for something moving at the speed they're measured
| to have from the height they're made is on the order
| of about 40 microseconds. That's about 28 times the
| rest frame half-life.

Yup, higher up they can spin more freely and last longer.
no biggie still.

What do you mean spin more freely? They're pointlike
paricles with a very small interaction cross section.
What's going to alter their spin? And more importantly,
what can change their spin at all, given that it's set
by their quantum properties?


| > | What can accelerate the muon after it's created?
| >
| > What can accelerate electrons after they are lost?
|
| You don't seem to appreciate the significance of the
| great mass and velocity these things have.

You don't seem to think about masses it is traveling through.
207 electrons is all it would have to hit to change it's course.
(even a car that wieghs a ton at any speed
can be influenced by 2000 one lb hits)

At the speed they're going, their relativistic mass
puts them at about 4600 electron masses. Then figure
the kinetic energy given their speed...

Try changing the course of a car travelling at 0.999c by
putting a few baby strollers in its path.

Also, why don't you look up the mean free path for somthing
the size of a muon in air. These buggers can pass through
rather significant amounts of matter without even feeling
a breeze.


| > | Interaction cross section is low, mean free path
| > | is large, gravity will have negligible effect.
| > | We know the speed when we detect them.
| >
| > You know the speed how?
| > You detected it fly by, and timed the exact same muon
| > a little bit further in it's path?
|
| We know the rest mass of the muon and we measure the
| kinetic energy deposited when they hit the detector.
| Simple math from there.

Ok,
but that still does not tell the speed it may be doing
up higher.

We know the energy at which they're created (pion decay)
because we know the process from lab experiments. So
we know the initial speed, too; they arrive with essentially
the same energy.

the end result does not always prove the path it took
nor the speed before such.

See above.

Basically, you do have some abstract proof of what you say.
But you sure do not have physical proof of the entire
life of such muons.
So, you can play with "time dilation muons" and abstract
proof all you want,
I will wait for actual physical proof before I jump to that faith
you have achieved..

In other words, you're going to hang onto your last,
irrelevant objection and claim it's a significant
problem.


.

Relevant Pages

  • Re: Consistancy of the speed of light.
    ... The speeds of ... they are moving like a bunch of electrons through electrons and atoms ... There is a need to do such to call it physical proof. ... To say one muon does such and such and it is proven ...
    (sci.physics)
  • Re: The Muon Double Speed Dilemma
    ... For the time being, the muon, would always create a required as a naturel ... ball during the very same toss is 58 mph. ... The speed also depends on the reference frame ...
    (sci.physics.relativity)
  • Re: speed, size, time
    ... |>> object 'shrink' in size, ... Maybe different speeds? ... |>> the direction of travel? ... | speed of electrons is a constant, it would all come out nicely. ...
    (sci.physics.relativity)
  • Re: Do muons prove SRT ?
    ... measuring the half life of the particle which is moving wrt that frame. ... earth bound observer that is about to be hit by the muon as it travels its ... the muon that agrees with General Relativity, ... muons to travel at relativistic speeds. ...
    (sci.physics.relativity)
  • Re: The Muon Double Speed Dilemma
    ... requires a simply a gravity matter, which the latter has had brought all its ... For the time being, the muon, would always create a required as a naturel ... the reference frame tied to a street sign, ...
    (sci.physics.relativity)