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Massless Energy & Nothing.


OmegaX7

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The quote means what it says. You can have energy without mass. But you cannot have mass without energy.

 

I hate that, I will have to study more. I can't argue the point because I am not smart enough to prove otherwise, but I still don't like it, hehe...Energy has no mass? Not having mass without energy I can grasp, hummmm...

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Actually, it would be more correct to say that "matter" is a form of energy. Mass is just a property of matter. Mass can be defined as that property of matter which causes it to have weight in a gravitational field - or to put it simlpy, that which causes something to weigh.

 

Pure energy has no weight, therefore the photon is massless (but to make matters worse it does have matter due to theory - a photon with frequency f has a mass of hf/c^2, where h is Planck's constant.

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I know I am not adding to this thread, but please reread the above quote and explain what it means...Energy cannot exist without mass if mass is concentrated energy. Even unconcentrated energy would have mass if the quote is true...

 

Smokinjoe9; Consider this example: Water can exist without ice, but ice cannot exist without water. Same principle, energy can exist without matter, but matter cannot exist without energy. Does this help you to understand???

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Where would a photon come from without some form of matter to produce it? I agree no theory proposes a pre big bang condition but to simply postulate that "it's just when we came into being" implys there was simply nothing before that time and you simply can't get something from nothing. But you might get mass/matter if you have enough energy. Right? Why couldn't there be 1 dimentional space? couldn't energy live there.

Omega,

 

I put in Bold your comment about what minimum requirement to create a photon. After thinking it

through, I realized it was a great question. Can a photon which is massless be created or spawned from

anything/particle which is itself massless ? There are interactions between neutrinos to produce or

absorb photons. Yet, it is now thought that neutrinos now are to have mass... The only other massless

particles I know of are Gluons and Gravitons. Neither have we seen directly. Gravitons are as of the

moment still theoretical while Gluons have at least some corroboration with Quantum Chromodynamics. I

at the moment am not aware of possible direct interactions of these particles with photons either

creating or destroying.

 

As for Vacuum Fluctuations. Their is ways to create something from nothing. This can occur actually

spontaneously. The lifetime is short dictated by Heisenberg's Uncertaincy Principle. So even though I

am not disagreeing with Paultr about BB not coming from nothing. I am showing that within our current

universe as is, briefly, QM can get you something for nothing...

 

You can mathematically make a 1-dimensional space, yet what is physical about it ? If you ignored

space in spacetime, then you have a 1-dimensional spacetime (meaningless yet so).

 

By separating different thoughts as above a reader can better discern what you the poster is

attempting to say. Good Luck posting and Welcome to Hypography! :rant:

 

Maddog

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It is simply not true that a photon has no mass. Einstien stated that inertial mass = gravitational mass. Light speed is a constant, which means, you cannot slow light down so the inertial mass is not a relevant issue. Light doesn't have a rest mass either because when a photon is infinitely redshifted, the light stops existing basically, it's potential energy is converted into gravitational energy (i.e. mass). Light does have gravitational mass and this can be observed.

 

A black hole is matter compressed down to the size of a particle. The matter increases in kinetic energy as it becomes denser and denser. The energy indeed has mass.

 

As for virtual particles:

 

They have energy. Where does this energy come form and where does it go?

You are trying to suggest it appears from nowhere and returns to nothingness at the end of it's existence. Explain this please?

 

Indeed energy has mass. Einstien's equation E=mc^2 shows us that mass is a measure of energy and vice-versa. Matter is energy but a better way of stating it is: matter is a form of compressed energy (not mass is compressed energy). Remember the atom bomb.

 

Damien

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It is simply not true that a photon has no mass. Einstien stated that inertial mass = gravitational mass. Light speed is a constant, which means, you cannot slow light down so the inertial mass is not a relevant issue. Light doesn't have a rest mass either because when a photon is infinitely redshifted, the light stops existing basically, it's potential energy is converted into gravitational energy (i.e. mass). Light does have gravitational mass and this can be observed.

Are you saying you can disprove this research at Harvard, "Optical computer made from frozen light"?

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Light does have gravitational mass and this can be observed.

 

No. Light has gravitational redshift, which is what you observe.

 

Light may appear to be "pulled" towards things, but this is an illusion. Ligh simply follows the shortest path between two points, which in Einstein's universe might be a curve around a gravity well.

 

A black hole is matter compressed down to the size of a particle. The matter increases in kinetic energy as it becomes denser and denser. The energy indeed has mass.

 

This is not correct. Black holes are huge monsters. If the Sun were to become a black hole today, it would have a 3 kilometer radius.

 

As for virtual particles:

 

They have energy. Where does this energy come form and where does it go? You are trying to suggest it appears from nowhere and returns to nothingness at the end of it's existence. Explain this please?

 

Virtual particles "borrow" energy from the vaccum when they pop into existence. This energy is repaid when they are annihilated. No paradox there.

 

Indeed energy has mass. Einstien's equation E=mc^2 shows us that mass is a measure of energy and vice-versa.

 

No, his formula shows the conversion rate between energy and mass. If you wish, pure energy has no mass and would appear at one end of the energy chart, whereas hevaily charged particles would appear at the high end of the energy charts. But free particles are usually extremely long lived unless they are taken into an atom, for examples.

 

Matter is energy but a better way of stating it is: matter is a form of compressed energy (not mass is compressed energy). Remember the atom bomb.

 

I corrected my use of the term "mass" to be "matter" a few posts ago, so this is that I said before. It doesn't work the other way. Energy can clump together and form mass. Mass can be annihilated and release energy. The energy itself is massless.

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Hi Tormod,

 

Gravity is a force that works on mass to change it's momentum. That is not really a correct statement because gravity is the curvature of spacetime. Spacetime is the universal rules that govern the nature of how mass MUST react to another mass.

 

When a mass changes momentum in a gravitational force it's potential energy is converted to kinetic energy. However a mass moving against a gravitational field will relinquish it's kinetic energy in exchange for potential energy.

 

Red shifting is the exchange to potential energy and blueshifting is the exchange to kinetic energy. We can only observe this change via the frequency of light. The light does not change velocity though.

 

The radius of the sun you are describing is the event horizon. This is a point where the escape velocity is greater than the speed of light. The actual sun however has continued to compress past this point and is now sitting at the centre of gravity and is the size of a particle.

 

Damien

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It is simply not true that a photon has no mass. Einstien stated that inertial mass = gravitational mass. ... Light doesn't have a rest mass either because when a photon is infinitely redshifted, the light stops existing basically, it's potential energy is converted into gravitational energy (i.e. mass). Light does have gravitational mass and this can be observed.

Actually, Damien, I was specifically speaking of Rest Mass as massless. The kinetic

energy of a photon is based upon the wavelength of the light/photon. Yes, I would

agree with you according the GT by Einstein in a gravitational field work would be

done on the photon by the g-field causing a reddening of the light (longer wavelength).

A black hole is matter compressed down to the size of a particle. The matter increases in kinetic energy as it becomes denser and denser. The energy indeed has mass.

No dispute about black holes. Italicized remark is a bit off what I was saying (out of

context), though I am not in disagreement in general.

As for virtual particles:

They have energy. Where does this energy come form and where does it go?

You are trying to suggest it appears from nowhere and returns to nothingness at the end of it's existence. Explain this please?

Virtual or not, unless you have not heard of Vacuum Fluctuations, it is quite normal to

have the Vacuum itself create from nothing. It is dictated by Heisenberg's Uncertainty

Principle alone.

Indeed energy has mass. Einstien's equation E=mc^2 shows us that mass is a measure of energy and vice-versa. Matter is energy but a better way of stating it is: matter is a form of compressed energy (not mass is compressed energy). Remember the atom bomb.

I wasn't disputing Einstein's equation. Though if you know of the bomb, then you know

all the mass isn't converted (though this would for anti-matter/matter anihilation). I

suppose you could say that exactly depending which way you dance on the notion of a

Higgs Fields existance. Standard Model predicts it, though no one has found them.

 

maddog

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Gravity is a force that works on mass to change it's momentum. That is not really a correct statement because gravity is the curvature of spacetime. Spacetime is the universal rules that govern the nature of how mass MUST react to another mass.

The bold statement is actually not quite right. A particle/object under the effect of the

gravitic field move according to the path of least resistance as shaped by geometric

effect of the force of gravity.

Red shifting is the exchange to potential energy and blueshifting is the exchange to kinetic energy. We can only observe this change via the frequency of light.

The effect is similar to hearing the change in pitch of a train whistle. It increases when

moving toward you and lowers when moving away. This effect in a gravity field is for

a different reason with the same effect. Frequency is convertable to wavelength and

are related. Frequency is the cycles per second of a completed wave. Wavelength is

the length in distance of that completed wave.

The radius of the sun you are describing is the event horizon. This is a point where the escape velocity is greater than the speed of light. The actual sun however has continued to compress past this point and is now sitting at the centre of gravity and is the size of a particle.

This bold remark is I think you funniest yet. You may have heard all scrambled or

remembered it this way. The sun you see is EXACTLY the same sun Actually there.

It is just the one that was about 8 minutes ago. With EXACTLY the same Radius.

A Black Hole has an Event Horizon of which is Dependent upon the mass of the

Black Hole. As Tormod said, one the mass of say 3*sun would be about 26 miles

in diameter or so. To have one about the size of a proton would imply it's mass is

about that of a small asteroid (one 10 miles across). I would read up on this. It is

great stuff! :rant:

 

maddog

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Light at rest does not have a mass because light is a constant c. How can something that never stops have a rest mass? Forgive me if this sounds a little absurd. My understanding is that when light infinitely redshifts it no longer exists as light. I hope you can explain this to me. But you didn't say whether light travelling at c has a mass.

 

I don't really understand vacuum fluctuations which is why I asked you to explain to me:

 

"They have energy. Where does this energy come form and where does it go?

You are trying to suggest it appears from nowhere and returns to nothingness at the end of it's existence. Explain this please?"

 

Your answer didn't quite help me understand. Heisenberg's UP is about: by knowing the position the less you know the momentum (of an electron). Vice versa. I don't have the actual wording on hand. How is this relavant?

 

The gravity thing I stated myself was not really correct.

 

I understand the wavelength of light and the shorter wavelengths move toward the longer wavelengths. Red shift. The gravitation force needed to create any noticeable effect is rather large. Which is different compared to the redshift we see as a star is heading away from us. Where the wavelengths actually stay where they are yet the wave changes length.

 

I think there has been some misunderstanding about the sun. We (Tormod and I) were discussing our sun if it had been compressed down to the size of a particle to create a black hole and not the sun in it's present state. In this case the the radius would be represented by the event horizon.

 

I'm not sure on the rest but I think we agree on most. These are just a few things we need to clear up.

 

Damien

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Hi Tormod,

 

Gravity is a force that works on mass to change it's momentum. That is not really a correct statement because gravity is the curvature of spacetime. Spacetime is the universal rules that govern the nature of how mass MUST react to another mass.

 

Spacetime is AFAIK simply the unification of space and time as required by Einstein's relaitivty theory. The laws of nature are not defined by spacetime...it is rather the other way around. The properties of spacetime are the results of the physical laws in our universe.

 

Anyway, how does this relate to the discussion of whether energy has mass or not?

 

Red shifting is the exchange to potential energy and blueshifting is the exchange to kinetic energy. We can only observe this change via the frequency of light. The light does not change velocity though.

 

My point was that light does not have mass per se. This whole thread is about whether there can be energy without mass, which I have tried to explain.

 

The radius of the sun you are describing is the event horizon. This is a point where the escape velocity is greater than the speed of light. The actual sun however has continued to compress past this point and is now sitting at the centre of gravity and is the size of a particle.

 

My point here was that it is the radius, not the singularity, that defines the black hole's gravitaional influence. Outside of the radius, the black hole's gravity is just like that of any other object. It is only inside the radius that strange things happen. I wrote this because earlier you wrote:

 

A black hole is matter compressed down to the size of a particle. The matter increases in kinetic energy as it becomes denser and denser. The energy indeed has mass.

 

Which is not really saying that energy has mass, but that the mass changes energy levels. Pure energy has no mass.

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