Mass of light.

No Position

Before I start a yelling stream at me let me make it clear I am not taking a position on a photons rest mass issue. But I am inclined to think that both sides should take a deep breath. There may be more to the story than you are considering.


It turns out that there have been several experiments subsequent to MM that tend to support an aether theory and that a photon has a rest mass. But since this data runs agrain Relativity they are being ignored.


http://redshift.vif.com/JournalFiles/Pre2001/V04NO2PDF/V04N2MU2.PDF

or: http://www.signaldisplay.com/relativity.html

I have found another research organization involved in gauge theory that says photons indeed may have mass although they general refer to it as the massless photon throughout their study:


http://www.aias.us/pub/mattersagnac.pdf
 
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Will an atom have a mass if you measure it with a device made of
"huge atoms", whose nuclei are as large as planets or stars?
 
There is no such thing as a "huge atom" with a nucleus the size of a star.
 
Originally posted by James R
There is no such thing as a "huge atom" with a nucleus the size of a star.
Click to expand...
I believe it would be called a solar system.
I have always toyed with the thought that each solar system was only an atom in a molecule of a cell of a much larger being.
with respect:cool:
 
grimreaper:

Solar systems and atoms are very different. The picture of an atom that most people are taught at school is of the atom as a kind of miniature solar system. The modern quantum picture of an atom is very different from that. It describes the atom as a nucleus surrounded by "clouds" of electrons whose positions at any time are uncertain, but which can be predicted probablistically.
 
thanks for the clarification

Thanks for the clarification. I am not up on quantum physics. So how dose this relate to the valence bonding then. One electron per orbit? I think I’ll probably need some aspirin but it’s worth it for enlightenment.
With respect
:cool:
 
Your confusion arises from the word orbit. You can use the word orbit so long as you don't associate with the classical analogy of orbiting sytems such as planetary orbits. Replace the word orbit with state. One electron per state. A state in the atomic sense, is characterised by 4 quantum numbers, n, l, m(l) and m(s) (m(l) and m(s) are meant to be subscripts).
 
What if a scale invariant and complete description of the universe is consistent with the existence of these “huge stellar and planetary like atomic nuclei”. What if the very massive source of the atoms building us creates from the center of the earth the puzzling smaller variation of the gravitational field over the oceans and continents than what is expected from their masses. Until the irrefutable origin of the universe is revealed we should explore all possibilities in a search for a self-consistent picture of creation.

Quantum mechanic describes, like the rest of physics, only what we see. How we influence observation and what creates what we see is still controversial. The discovery of what creates what we see will not reject quantum mechanics or any other well checked theory. It will only show WHY we came to these descriptions of nature and in the same time it will expand the scope of understanding.

Probably there are no such things as quarks, which strangely enough know no unbounded states. And the discrete structure of the atomic nucleus can be accounted for by something simpler, connected to the universe beginning like one all-building scale independent, finite and discrete 3D-spiral interaction.
 
Peter2003:

<i>What if a scale invariant and complete description of the universe is consistent with the existence of these “huge stellar and planetary like atomic nuclei”.</i>

It isn't. Atoms and planets are quite different.

<i>Until the irrefutable origin of the universe is revealed we should explore all possibilities in a search for a self-consistent picture of creation.</i>

Yes, but let's not hang onto possibilities long after they have been shown to be false.

<i>Quantum mechanic describes, like the rest of physics, only what we see. How we influence observation and what creates what we see is still controversial. The discovery of what creates what we see will not reject quantum mechanics or any other well checked theory. It will only show WHY we came to these descriptions of nature and in the same time it will expand the scope of understanding.</i>

This is philosophy, not physics.

<i>Probably there are no such things as quarks, which strangely enough know no unbounded states. And the discrete structure of the atomic nucleus can be accounted for by something simpler, connected to the universe beginning like one all-building scale independent, finite and discrete 3D-spiral interaction.</i>

There is no evidence that this is the case.
 
Originally posted by James R
There is no such thing as a "huge atom" with a nucleus the size of a star.
Click to expand...

the neutron star is very often likened to a single huge nucleus, the size of a star.
 
It is likened, but we know that the 2 are definately not the same.
For one, gravity plays a much more important role. Also you should know that there are no stable neutron nuclei.
 
Questions

To all,

Yes, atoms and planets are quite different at the scales of observation created by the atoms that build us.
But have we any idea how the earth will behave in a giant hand that squeezes it together with the moon? This hand will feel like squeezing a balloon according to Savov’s theory of interaction, or like a tiny hand squeezing and atom, due to revealed 3D-spiral structure of the space between the earth and the moon. This 3D-spiral structure offers the simplest and singularity free explanation of structure buildup in the universe as an interaction between multiscale self-reproducing and so self-similar sources of interaction, some seen as galaxies, stars, planets, atoms and light depending on their size.

Meantime the collapse of the sources of the atoms in centers of stars and planets leaves very massive dense and rotating 3D-spiral interactions, which are considered as neutron stars in the terms of what we have at hand – the atomic structure that builds everything around us. It is very likely that there are more things in heaven and earth than are deemed in anybody’s philosophy as it is argued in one of greatest plays of all times (Hamlet).

The great puzzles of understanding imply that either nature is really enormously complex or that the initial objects set in the foundations of physics should be reconsidered. The study of dynamical systems, e.g. see Gleick’s CHAOS Making a New Science and many similar titles imply that complexity of nature is likely to be born in our minds.

The inward 3D-spiral vorticity of the found 3D-spiral interaction that builds the source of the earth’s atoms pushes them inward and thus creates what we call earth’s gravitational attraction. The outward 3D-spiral vorticity prevents the moon from falling on the earth. At much smaller scales the electron never falls on the proton and the discreteness of these 3D-spiral patterns if interaction accounts for the discrete orbits of the electron.

How can the big bang universe beginning generate the clumpy structure of the universe at all scales from flying away from each other elementary particles of uncertain origin and structure. Consider this: the distance between every two particles increases in the just born big bang expanding universe. Then their interaction has to decrease also. How can you trigger any structure buildup in a domain of a decreasing interaction? It is much simpler to obtain everything from one unfolding to smaller scales interaction rather than to start from very small sources of interaction (elementary particles, puzzling matter antimatter asymmetry and so on) for multiscale structure buildup.
 
Peter2003, we've been through this before. Until you can explain what you mean by "3d spriral structure" in simpler terms, the theories you are trying so hard toconvinse everyone of are useless.


me:"purple monkey bus"
you:"what"
me:"it explains everything. purple monkey bus. check out this link"
you:"that link says nothing about 'purple monkey bus' what does it mean?"
me:"it means everything. it explains how the universe works. purple monkey bus is very greataford and versimilitude."
you:"huh? that doesn't make any sense. what is purple monkey bus"
me:"it explains everything. check out this link."
you:"but that link doesn't explain what I'm asking! what is purple monkey bus??"
me:"it explains everything. check out this link."
....

please take you assumptions doewn to their base level, and explain them from there if you want peop0le to understand what you are saying. What is, and what makes up a thing wherein the universe is a 3d spiral? Please use simple geometric terms and math to explain. do not define it with other items which are as yet undefined. Assume I know nothing about the universe *AT ALL* and tell me what it is, in your understanding. start with space. then matter. then energy. then time. then whatever else you want to branch into.

and please start as new thread to do this in, instead of filling up everyone else's thread with this theory until it has more than ust you and the author backing it. Once you have shown that the theory has some serious reality to back it, then you can start using it to answer other people's questions.
 
Hello. I'm new to the group. This is one of my favorite subjects so I decided to post on this topic first.

First - Many physicists do tend to not use the concept or relativistic mass but that is a matter of personal taste. More people use it in places like cosmology then they do in particle physics. This should be noted since its quite wrong to assume that a relativist means rest mass when he uses the term "mass."

And whether light has mass depends on how you define the term "mass". Inertial mass (aka "relativistic mass) is defined as the quantity "m" such that the quantity "mv" is defined in collision processes. Once m is determined then so is mv. Then the quantity mv is defined as momentum and given the name p. If the particle is a tardyon, defined as a particle for which v < c then m is a function of velocity, i.e. m = m(v) The quantity m(0) = m_o is then called its "proper mass" aka "rest mass". I prefer the term "proper mass" myself. Then

m(v) = m_o/sqrt[1-v^2/c^2] = gamma*m_o

where

gamma = 1/sqrt[1-v^2/c^2]

The momentum is then given by

p = mv = gamma*m_o*v

The kinetic energy of the particle is found through the work-energy theorem, i.e. the work done on a particle equals the particle's change in kinetic energy. It can then be shown that

K = (gamma - 1)m_o*c^2 = gamma*m_o*c^2 - m_o*c^2

The quantity m_o*c^2 is the particles rest energy E_o. Substituting in m we get

K = mc^2 - E_o

or

mc^2 = K + E_o

This is called the "total energy" but it really isn't since it doesn't include the potential energy. I call this "inertial energy." Let E represent this quantity. Then

E = K + E_o

It can be shown that

E^2 - (pc)^2 = (m_o*c^2)^2

The momentum of the photon is related to its energy as E = pc. Substituting into this equation we get

m_o = 0

That is what people mean when they say "a photon has zero proper mass". It's not really a valid thing to do since the derivation is carried out by *assuming* the particle's speed could change and that's impossible for a photon.

If the particle is a photon then the mass is given as m = p/c where c = speed of light and p = magnitude of its momentum. Since p = hf where h = Plancks constant and f the photons frequency then m = hf/c.

There are three aspects of mass and therefore three kinds of mass

(1) Inertial mass - The "m" in "p = mv"
(2) Passive Gravitational Mass - That upon which gravity acts.
(3) Active Gravitational Mass - That which creates a gravitational field.

A beam of light is deflected by the sun because it has (passive gravitational) mass. In fact both Richard Feynmab and Albert Einstein said this.

A beam of light can also generate a gravitational field - i.e. it has an active gravitational mass.

Someone said that light isn't bent by the sun because it travels in a straight line in spacetime. That is not quite right. To be precise one should say that light moves on a pass of extremal length. The path of light is a geodesic and that is all that is required. This does not mean that the light does not have a straight line in *space*. Note that saying that light is deflected due to curved spacetime and not due to gravitational attraction is wrong. These are identically the same phenomena which is simply described in different languages. The later being described in the language of differntial geometry.
 
Einstein showed that inertial mass and what you call "active gravitational mass" are the same thing. In the general relativistic picture, there is no need for a concept of "passive gravitational mass". Inertial mass is all that is required.
 
Light has "no mass" is a current theory that physicists like to hold because it has yet to be proven wrong. Assuming this allows for all the wonderful equations and experiments that we have in our pursuit for the T.O.E. It is taught in class because this seems to be the general consensus and why fight with it. SOmeone's gotta have a lot of guts and funding or time to do such a thing.

However it also depends on how you define mass. which i believe is based on some scale. I myself don't believe in it being massless...just negligible mass!
Its sort of like viewing an axis or plane...a point really has no quantity but mixed in with a bunch of other points you can get some measurement, in this example distance

As for curved space:
the best 2 examples are the (1)orange and the bowl and (2)the toilet flushing.
The bowl center acts as the "sun" and the orange is the object in orbit.
The toilet bowl is the region bounded by the gravitational forces of the "sun"
and if its let to continue flushing without sucking anything in, the things will orbit.

And it is this latter example that i think its more believable...that is little particles pushing the gravitational bending rather than the space actually bending on its own.
DAMN PHYCISIST TERMINOLOGY
 
James R said:
Einstein showed that inertial mass and what you call "active gravitational mass" are the same thing. In the general relativistic picture, there is no need for a concept of "passive gravitational mass". Inertial mass is all that is required.
Click to expand...


Actually Einstein showed that inertial mass is proportional to *passive* gravitational mass. One then chooses units to set the constant of proportionality equal to one.

And is would be incorrect to say that there is no need for passive gravitational mass. For one thing we must keep in mind the different ways in which these terms are defined so that we can test the theory. Also, passive gravitational mass is what is being weighed when you step on the bathroom scale. And weight is a function of speed. Thus a moving body weighs more than the same body at rest.

For example: Suppose you're in a frame of reference in which there is a uniform gravitational field. The gravitational accelertion is along the z direction, i.e. drop a stop and it accelerates relative to your frame, in the -z direction. Place a scale at z = 0. Place a body on the scale and let it move with speed v. Then the weight is

W = m_p*g

where m_p = passive gravitational mass. Since passive gravitatioinal mass equals inertial mass then

m_p = m = m_o/sqrt[1-v^2/c^2] = relativistic mass

And keep in mind that the "curved" in "curved spacetime" is just a term carried over from differential geometry. Nothing is really physically curved per se. The curvature is simply a mathematical statement about the mathematical manifold we call "spacetime." It's these mathematical things which describe the physical world. The physical manifestation of this curvature is tidal forces, i.e. the deviation of the trajectories of two particles in free-fall.

Note that spacetime curvature cannot be used to describe all gravitational forces. For example: There is no spacetime curvature in a uniform gravitational field and yet particles are still deflected by such a field.
 
pmb said:
Note that spacetime curvature cannot be used to describe all gravitational forces. For example: There is no spacetime curvature in a uniform gravitational field and yet particles are still deflected by such a field.
Click to expand...

Hey, this is new thing for me. Are you sure about this, that there is no spacetime curvature in a uniform gravitational field? I believe that general relativity is a more general gravitational theory than Newton's theory. However, if what you said is true, it would mean GR is not better than Newton's theory after all. :)
 
Paul T said:
Hey, this is new thing for me. Are you sure about this, that there is no spacetime curvature in a uniform gravitational field? I believe that general relativity is a more general gravitational theory than Newton's theory. However, if what you said is true, it would mean GR is not better than Newton's theory after all. :)
Click to expand...

Yes. I'm 100% positive. Spacetime curvature and tidal gravity are precisely the same thing expressed in different languages. Since a uniform gravitational field is defined as a gravitational field with no tidal forces then it follows that there is no spacetime curvature.

Consider Einstein's equivalence principle: A uniform gravitational field is equivalent to a uniformly accelerating frame of reference.

Consider an inertial frame of reference in flat spacetime. There is obvioulsy no spacetime curvature in that frame. Now go to a uniformly accelerating frame of reference. Since spacetime curvature is absolute then it follows that there is no spacetime curvature in this frame of reference and since this is equivalent to a uniform gravitational field then it follows that there is no spacetime curvature in a uniform gravitational field.

If a gravitational field does have spacetime curvature then the equivalence is only local, i.e. restricted to a region so small as to consider the field to be uniform.

This is all in the GR literature especially in Einstein's paper

"The Foundation of the General Theory of Relativity," by Albert Einstein (1916)
(Annalen der Physik 49)

Note what Einstein says in that paper

"It will be seen from these reflexions that in pursuing the general theory of relativity we shall be led to a theory of gravitation, since we are able to "produce" a gravitational field merely by changing the system of co-ordinates. "

In Einstein's general theory of relativity (and by this I mean as interpreted by Einstein himself and not as interpreted people who disagree with Einstein) the gravitational field has a relative existance. Spacetime curvature does not have a relative existance


This is also in the paper "Principle of Equivalence," F. Rohrlich, Ann. Phys. 22, 169-191, (1963), page 173

In this paper the author defines a uniform gravitational field as a gravitional field which has no spacetime curvature.
 
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