Massless Energy & Nothing.

[Tormod]

I'm sorry Tormod but I'm sure I'm not the only one who will have something to say about that....

 

You go out of your way, indeed.

[Eduffy80911]

Has it not been established that Energy has mass: M=E/C^2?

[Tormod]

Has it not been established that Energy has mass: M=E/C^2?

 

Please read through the thread before you post - this has already been commented upon.

[BlameTheEx]

There must be a single cause of gravity.

If the photon creates a gravitational force, a photon being energy, and all mass consisting entirely of energy, would it be consistant to say that energy/photon is the cause of gravity ?

 

This would mean that G - gravitational constant - must be able to be derived from the energy/photons radiating from a mass.

 

It is more basic than that. Gravity is a function of energy. It does not matter what form the energy is in. At least that is my interpretation of the available evidence.

 

Maybe something like "Dark Energy" will prove to be massless or even have negative mass. If so I don't think the evidence is sufficiently clear as yet.

[Damo2600]

Red shift doesn't change the group velocity of light. It alters the position of some of the waves i.e. the shorter wave lengths move toward the longer wavelengths. Universal redshift (the redshift that occurs when a planet is moving away from us) alters the wavelength of the shorter wavelengths however they stay in the same position. During all this the group velocity never changes in any situation.

 

Damien

[Smokinjoe9]

I like this thread it has shown me that there really is no answer to the question, well there may be an answer but no one REALLY knows it....What is mass REALLY??What is force REALLY???

[Damo2600]

Hi blame the Ex

 

Gravity is a function of energy. So gravity is also a function of mass. Universal gravity or dark energy, as it is sometimes refered to, must also have mass. This dark energy you are refering to has not been found. One particular physicist suggested that this dark energy seemed to him to be a somewhat imaginary substance to comfortably function as a universal gravity that we can't explain. This particular viewpoint is not well shared within the scientific community so it cost him his career. He has since had certain mental problems. However, the point is, not all physicists accept this notion of a dark energy yet are not at liberty to say if they want to keep their pay checks coming in (edit: and maintain any influence or respect). :circle:

 

Damien

[WebFeet]

It is more basic than that. Gravity is a function of energy. It does not matter what form the energy is in. At least that is my interpretation of the available evidence.

I almost fully agree.

 

For gravity to be a function of energy would imply that energy has some manner of attractive force that would have to act at a distance. This would make energy a complex system as opposed to a fundemental building block.

 

Consider this.

Gravity is not a function of a single particle of energy, but an effect created when two particles of energy meet. When ever an energy particle travelling through space encounters another, the premeability of that region of space decreases, the same effect as if the refractive index of the medium had increased. The direction and speed the energy is travelling in is effected, causing it to deviate from its original course.

[BlameTheEx]

I almost fully agree.

 

For gravity to be a function of energy would imply that energy has some manner of attractive force that would have to act at a distance.

Just so. Any lump of energy from a star down to a single photon has its own gravitational field.

 

IThis would make energy a complex system as opposed to a fundamental building block.

I am a little uncertain of your use of "complex system". The situation seems simple to me - energy attracts energy. The formula for gravity is not complex.

 

IConsider this.

Gravity is not a function of a single particle of energy, but an effect created when two particles of energy meet. When ever an energy particle travelling through space encounters another, the premeability of that region of space decreases, the same effect as if the refractive index of the medium had increased. The direction and speed the energy is travelling in is effected, causing it to deviate from its original course.

 

Hm. Gravity acts at a distance. Particles need not meet. As gravity stretches to infinity one could argue that every particle ALWAYS interacts with every other particle in the universe.

 

I have not heard of gravity defined as reduction of permeability (have I got the spelling correct?) before. Can you explain why that causes an apple to drop?

[lindagarrette]

It is my understanding that Einstein's General Relativity theory contains the only "proven" theory of gravity. Everything else is just conjecture. So far no connection has been made between particles (the three forces) and the effect of warping space/time. I don't see why gravity is considered to be a force.

[WebFeet]

Just so. Any lump of energy from a star down to a single photon has its own gravitational field......I am a little uncertain of your use of "complex system". The situation seems simple to me - energy attracts energy. The formula for gravity is not complex.

How does energy attract energy ?

 

If energy were to attract energy the would have to be some sort of emission from the energy to facilitate such an attraction. If so, what is powering the emission. If the energy itself were powering it, then this would result in a reduction in its own energy. If a photon's graviational field consumed its own energy, then the half life of photons could be calculated based on their energy level.

Currently we can look at Galaxies as they were billions of years ago. The light that we see, or rather that Hubble sees, was emitted billions of years ago. Surely if every photon generated its own graivtational field, they would become depleated of energy long before they reach here, billions of years later.

 

You never get something for nothing, unless you collect taxes.

 

I have not heard of gravity defined as reduction of permeability (have I got the spelling correct?) before. Can you explain why that causes an apple to drop?

Put a pencil in a glass of water, the pencil looks as if it is bent. It's just refraction. Light going from one medium into another with a higher refractive index. The light is bent, not the pencil. The closer you get to the earths surface, the higher the concentration of energy. When the apple decides to jump out of its tree, it could just float there in mid air, but as the energy in the apple encounters a higher concentration of energy, even a very small increase, the course the energy is taking will bend towards the higher concentration. As each particle of energy in the apple if effected in the same way, the closer the apple gets to the ground until it makes contact.

 

Google for Polarized Vacuum for a comparison to GR.

[Damo2600]

Youg guys are so confused.

 

Mass is a measure of the weight of energy. We can measure the mass of energy. If energy does not have mass then mass is merely an imaginary concept to describe the way energy attracts energy. A force is a misleading, imaginary construct to measure the curvature of spacetime that mass/energy causes. The idea that when an object moves under a gravitational force it is being pulled is a subject that has provided a lot of heat yet very little light.

 

So web feet you are correct to question all this. If all matter consists of energy then perhaps mass (or weight) doesn't exist at all it is merely the curvature of spacetime that moves energy along a straight line. Then the EM waves that energy causes is the curvature of spacetime it causes in a waving motion. However mass is a measurement of an object. If you can know the radius and mass of a planet you can measure it's size. So whether mass is what we think it to be (i.e. weight) it matters not really because it exists as a measurement of something. Energy does have mass whatever that means.

 

Damien

[WebFeet]

If all matter consists of energy then perhaps mass (or weight) doesn't exist at all it is merely the curvature of spacetime that moves energy along a straight line.

With the absence of mass, the reliance on spacetime to account for movement is also absent. The curvature of spacetime is dependant on the presence of mass. In which case all you're left with is energy.

 

Saying that mass doesn't exist, it's only energy is like saying that you car doesn't exist it's only a collection of parts. Sure, if you strip your car down all you have is a pile of parts, but when those parts are assembled together you have a car capable of burning fuel to achieve motion.

The same is true of mass and its component parts, energy.

[Damo2600]

Hi Webfeet,

 

I was making a point that light is energy and it has mass. However what is mass? Mass we know is a function of energy and we can measure it. Perhaps spacetime is dependant only on energy and the appearance of mass can be measured.

 

You seem to be a curious individual and I was catering to your curiosity.

 

I will restate - "Energy has mass what ever that means".

 

Light DOES have mass whatever that means. Mass is merely a mathematical measurement involved with momentum.

 

Damien

[WebFeet]

You seem to be a curious individual and I was catering to your curiosity.

Damien,

I've been called a lot of things in my time, but it's the first time I've been called a curious individual, except maybe in a dusty old school report.

 

I was making a point that light is energy and it has mass. However what is mass? Mass we know is a function of energy and we can measure it. Perhaps spacetime is dependant only on energy and the appearance of mass can be measured.

Mass is not a function of energy. Energy in isolation has very little function. It's only when energy meets energy that things start to happen. The system that is created when energy comes together has additional properties that are not inherant in energy.

Just like your car, it has properties that you will not find in its components. It's only when they all come together that it becomes a car. Change the way you put the components together and it becomes a different car.

 

Mass is a higher order structure than Energy. Mass for one thing has dimensions, energy is dimensionless, it is no more than a coordinate. If you take two coordinates, you have a dimension you can measure, mass.

 

If light were to have mass, then according to SR, it couldn't travel at the speed of light.

 

The properties associated with the mathematical model that is SpaceTime can also be demonstrated using only energy.

[Tormod]

Mass is a higher order structure than Energy. Mass for one thing has dimensions, energy is dimensionless, it is no more than a coordinate. If you take two coordinates, you have a dimension you can measure, mass.

 

If light were to have mass, then according to SR, it couldn't travel at the speed of light.

 

Thank you, WebFeet. This is the exact point I've been trying to get across.

[Damo2600]

Fighting a losing battle.

 

And I worked so hard. Phew.

 

I hope someone read this thread and came to the conclusion that energy has mass. You know if I just reached that one individual... It'd b all worthwhile. sniff

 

Later guys

 

Damien