# Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.

*From*: "tomgee" <tyropress@xxxxxxxxx>*Date*: 6 Jul 2006 12:58:45 -0700

Phineas T Puddleduck wrote:

http://www2.slac.stanford.edu/vvc/theory/relativity.htmlPaddlebutt, you and PD just make up physics as you go

Momentum

For non-relativistic objects

along, doncha? Pray tell us, quick before the Stooges

gallery jumps to help you, what it is you're calling "non-

relativistice objects".

I know what relativistic objects are: figments of your

combined imaginations from the SR subset of relative

motion. Are you saying "non-relativistic objects" are

those real things that we can empirically research?

And just when does speed become relativistic, PQuack?

Newton defined momentum, given the symbol p, as

the product of mass and velocity -- p = m v. When speed becomes

relativistic, we have to modify this definition -- p = gamma (mv)

When it's in your head?

So you're saying here that anyone can arbitrarily make a real

Notice that this equation tells you that for any particle with a non-zero mass,

the momentum gets larger and larger as the speed gets closer to the speed of

light. Such a particle would have *infinite* *momentum* (SNICKER) if it could

reach the speed of light. Since it would take an infinite amount of force (or a

finite force acting over an infinite amount of time) to accelerate a particle

to infinite momentum, we are forced to conclude that a massive particle always

travels at speeds less than the speed of light.

Some text books will introduce the definition m0 for the mass of an object at

rest, calling this the "rest mass" and define the quantity (M = gamma m0) as

the mass of the moving object.

massive object into a massless object at will? I always knew

that Mandrake could do that, but not that physicists or teachers

have the same magical powers.

Of course, but what if you choose the wrong mass?

This makes Newton's definition of momentum still

true provided you choose the correct mass.

Can you fix that with a wave of your Mandrakian wand?

Oh, you're narrowing your studies to that, are you?

In particle physics,

Which is the same as saying, "We ignore the energy

when we talk

about mass we always mean mass of an object at rest and we write it as m and

keep the factor of gamma explicit in the equations.

accruing to the object due to its motion, since it and us

are at constanct velocity wrt each other, and the speed

gamma cancels out." Or, "There is no such thing as an

object at rest, but we can imagine there is some such by

comparing the motion of objects that are moving at the

same speed and direction as we are." There is nothing

invalid about that, unless you claim it represents reality.

What ignorance? That has already been covered long

http://physics.nmt.edu/~raymond/classes/ph13xbook/node76.html

http://galileoandeinstein.physics.virginia.edu/lectures/mass_increase.html

Much more dramatically, in modern particle accelerators very powerful electric

fields are used to accelerate electrons, protons and other particles. It is

found in practice that these particles become *heavier* *and* *heavier* as the

speed of light is approached, and hence need greater and greater forces for

further acceleration. Consequently, the speed of light is a natural absolute

speed limit. Particles are accelerated to speeds where their mass is thousands

of times greater than their mass measured at rest, usually called the "rest mass"

Now shall we make it SPNAK 4 for you TG, or are you gonna admit your ignorance.

before you got here. It's new to you since you just began

to read about it, but it's old hat to regular poster here. I

would not advise you to waste our time by posting stuff

you just learned.

BTW, how can those particles get heavier and heavier if

they are massless? Oh, that's right - you Stooges have

magic wands!

But you can, right?

I think we both know the answer. You can't shut up.

.

**References**:**Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.***From:*tomgee

**Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.***From:*Phineas T Puddleduck

**Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.***From:*tomgee

**Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.***From:*Phineas T Puddleduck

**Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.***From:*tomgee

**Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.***From:*Phineas T Puddleduck

**Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.***From:*Phineas T Puddleduck

**Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.***From:*Phineas T Puddleduck

**Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.***From:*tomgee

**Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.***From:*Phineas T Puddleduck

**Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.***From:*tomgee

**Re: PHOTON MASS -- A FACT. MASSLESS PARTICLES -- NOT FACT.***From:*Phineas T Puddleduck

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