In article <PM03g.8708$Qz.311@fed1read11>, "LawsonE" <nospam@nospam.com>
writes:

<mmeron@cars3.uchicago.edu> wrote in message
news:b303g.11$15.486@news.uchicago.edu...

In article <1145866340.769870.18000@u72g2000cwu.googlegroups.com>, "Eric
Gisse" <jowr.pi@gmail.com> writes:

mmeron@cars3.uchicago.edu wrote:

In article <cDZ2g.8699$Qz.2770@fed1read11>, "LawsonE"
<nospam@nospam.com> writes:

"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:sIX2g.117900$oL.8310@attbi_s71...

Golden Boar wrote:

Photons have an infinite mass!

Sorry--Into into the killfile with you troll! *Plonk*

Still think you should research the number of legs on a horse...

Oh, it has been proven long time ago that a horse has an infinite
number of legs.

But this horse has only two!

http://img233.imageshack.us/img233/338/bipedhorse3bw2ba.gif

That's a truncated version.

Simplification for engineering purposes...

A physicist would simplify one step further, making the horse legless
and spherical.

<mmeron@cars3.uchicago.edu> wrote in message
news:bW03g.13$15.469@news.uchicago.edu...

In article <PM03g.8708$Qz.311@fed1read11>, "LawsonE" <nospam@nospam.com>
writes:

<mmeron@cars3.uchicago.edu> wrote in message
news:b303g.11$15.486@news.uchicago.edu...

In article <1145866340.769870.18000@u72g2000cwu.googlegroups.com>, "Eric
Gisse" <jowr.pi@gmail.com> writes:

mmeron@cars3.uchicago.edu wrote:

In article <cDZ2g.8699$Qz.2770@fed1read11>, "LawsonE"
<nospam@nospam.com> writes:

"Sam Wormley" <swormley1@mchsi.com> wrote in message
news:sIX2g.117900$oL.8310@attbi_s71...

Golden Boar wrote:

Photons have an infinite mass!

Sorry--Into into the killfile with you troll! *Plonk*

Still think you should research the number of legs on a horse...

Oh, it has been proven long time ago that a horse has an infinite
number of legs.

But this horse has only two!

http://img233.imageshack.us/img233/338/bipedhorse3bw2ba.gif

That's a truncated version.

Simplification for engineering purposes...

A physicist would simplify one step further, making the horse legless
and spherical.

That's called a "cow."

Golden Boar wrote:

PD wrote:

Golden Boar wrote:

PD wrote:

Golden Boar wrote:

PD wrote:

Golden Boar wrote:

I think that I have discovered that photons are not massless.

Mass is the resistance to a change in motion.

If a photon had no mass, then a photon would have no resistance to a
change in its motion.
If a photon had a little amount of mass, then it would have little
resistance to a change in it motion.

According to the above 2 statements, it would be easy to change the
speed of a photon.
Since we know that a photons speed is constant, it is not possible for
a photon to have a small amount of mass, or for a photon to be
massless.

For a photon to have a constant speed, it must have an infinite
resistance to a change in its motion, which can only mean one thing:

Photons have an infinite mass!

Which would pose a small problem. Infinite mass would imply infinite
gravitational attraction, which would mean that our universe would have
a hard time surviving for 14B years without gravitational collapse.

It would pose no such problem. Infinite mass would not imply infinite
gravitational atrraction, because gravitational attraction is a result
of energy, not mass.

You might have to explain to me what the energy is that holds you to
the Earth, what the energy is that holds lunar landers on the moon.

If you think that it is mass that causes gravitational attraction, they
why are massless protons affected by gravity?

Massless protons? You mean massless photons?

Oops, yes i meant massless photons :)

First of all, just because massless photons are attracted by gravity
doesn't mean that massive protons aren't attracted by gravity. You,
sir, are made of protons, and you do indeed feel gravity.

Secondly, it is *both* mass and energy that causes gravitational
attraction.

The fact that massless photons cause gravitational attraction suggests
that it is energy, not mass, which causes that attraction. Since
everything we know that has mass, also has energy, what proof do you
have that mass is causing gravitational attraction?

Because *quantitatively*, the amount of the attraction is proportional
to the mass. (Strictly speaking, and as I mentioned to you, we know
that the amount of attraction is actually due to a combination of mass
and energy.) Your qualitative mush-mouthing without checking whether
the *numbers* work out shows how easy it is to fool yourself with
qualitative mush-mouthing.

I guess you are talking about the equation F = G.m1.m1/r^2.
This can be rewritten as

F = E1.E2 / (F_P.r^2)

and

F_P = hbar.c / l_P^2

which gives the equation

F = l_P^2.E1.E2 / (hbar.c.r^2)

where,

E1 and E2 are energy packets
r is the distance between the two packets of energy
F_P is th Planck force
hbar is the reduced Planck constanst
c is the speed of light in a vacuum
l_P is the Planck length

Please demonstrate how this equation works for the force of attraction
between you and the Earth when you're standing on the surface. You will
have to show where you get appropriate values of E1 and E2 for you and
the Earth.
Some useful numbers:
Mass of Earth = 6.0E24 kg
Radius of Earth = 6.4E6 m

(I expect that if your mass is, say, 80 kg, the result of this
calculation should be a little less than 800 N, which is the
experimentally measured value.)

Since I cant find an equation for calculating the gravitational
attraction between photons, I cannot say if works for them. Perhaps you
could help in this regard?

The problem you suggest, is simply not a problem at all.

When something stupid like this comes up, it's time to erase everything
from the chalkboard and mutter, "No, that's obviously crap."

It is simple logic.

1) A photon has constant speed.
2) The fact that it has constant speed means that there is no change to
it's motion.
3) The fact that there is no change to its motion, means it has an
infinite resistance to changes in its motion.
4) Mass is defined as being the resistance to a change in motion.

Which of the above statements do you disagree with?

4 in particular. And because 4 is incorrect, then 3 is incorrect,
because you are using 4 to conclude 3.

The validity of 4 in no way affects the validity of 3

Infinite resistance to a change in motion, simply means that its motion
does not change. It does not link mass with resistance to change in
motion.

OK, look at it a different way. Newton's first law says that the fact
that there is no change to a body's motion indicates that there is no
net force acting on the body. This is a completely disjoint conclusion
from the one you draw.

Applying a force to a photon does not change its state of motion, it
changes its wavelength and frequency.

Reference for this? Example?

What makes you think 4 is incorrect?

Because that's not what mass means, except in a very narrow context.
The *conserved physics quantity* invariant mass is a *quantitative*
property of a system, defined by sqrt(E^2 - p^2). You may say, "But
that's just math". And to that I tell you: That's how we establish
which properties have physical value. Energy is of interest because it
is a conserved *quantitative* property of a system. Electric charge is
of interest because it is a conserved *quantitative* property of a
system, and it tells us something about the *quantitative* strength of
interactions. Linear and angular momentum is of interest because it is
a conserved *quantitative* property of a system. Mass is of interest
because it is a conserved *quantitative* property of a system, and it
tells us something about the *quantitative* strength of interactions.
And so on and on and on....

Mass is a measure of a body's inertia . Inertia is the resistance to
changes in a body's state of motion. These are the definitions that
result from Newtons work and which Einstein used in special relativity.

Yes. Newton only considered a finite class of objects. He did not
consider massless objects, nor did he know anything about any
invariants of a system except for momentum. Einstein, on the other
hand, did. The definition of invariant mass that stems from Einstein's
work is the one that I showed you.

PD

You seem willing to accept that for some cases but not for others.

When you recognize what makes physical properties useful, and *how*
they are useful, then you will have a better grip on physics.

PD

So maybe it can mean a completely different thing:
That F=ma doesn't apply to photons.
or
That the proposed definition of mass isn't as good as you thought.

PD

If a photon had infinite mass, then F=ma would not apply to the photon
as we would have the following equation, F = infinity * a.

Similarly, the equation, E = mc^2 does not apply to the photon, as we
would have, E = infinity * c^2.

The fact that photons have infinite mass, explains why these equation
don't apply to the photon.

The fact that photons are made of ectoplasm would also "explain" why
these equations don't apply to the photon. Except that they're not.

PD

Think about this idea, test this idea, post some problems that may
arise because of this idea.

Can you think of any pridictions that this idea would give rise to?
Can ytou think of any problems that this idea would solve?

Don't dismiis this idea so quickly.