matter made of space not energy?

[paultrr]

There is a bit of a misunderstanding there on Lorentz. Its time and length only that contract as one accelerates. Height and width stay the same irrespective of the velocity involved. So in general, anything accelerated still has dimensional properties. Our spacetime since the advent of Relativity is considered 3+1 dimensional.

Also, it is correct that mass is conserved in all reactions known. In fission and fusion that applies.

The vacuum does have energy. Cashmir experiments have shown this many times over. However, that energy cancels to at least 120 powers across the board as experiments and observations also show us.

[alxian]

i always understood that matter was super compact energy (atoms being made up of very little actual 'stuff' its mostly the bonds as mention earlier that we get our energy from), at least in such a way that the bonds between atoms can be broken, this potential energy is so great that a reaction based on a football worth of reactant can turn into a city leveling mushroom cloud.

while i never proffessed a perfect understanding of nukes i never though about whats left over after (after part of that nuclear energy, from the atomic bonds, is used to propagate the explosion (shattering even more nuclei nearby)), i.e. sure the reactant will be used up (in controlled nuke reactors this efficiency is like 5%) but in a nuclear bomb built with enriched uranium and specifically design for maximum yeild.. what is that yeild? what is the efficiency of a nuke? a better wording would be if matter (at its most fundamental) isn't 100% compressed energy and the potential within an inefficient nuke is still great enough to cause a mushroom cloud a the resulting fallout (that which is left over after the nuke has stopped reacting (violently)) how much power is stored within the strong force of enriched uranium (any atom for that matter). can controlled nuclear reactions ever tap that potential? with recycling they say sure why not, but i mean in one shot ultimate power in a regenerative controlled nuclear melting process, where the nuclear explosion is slow and controlled but complete leaving very little waste when its complete.

now... as for the topic.. technically yes the atom is made up mostly of space (between the electrons and nucleus, and then again between that individual components of the core), the rest is minute amounts of stuff that makes up the nucleus. so at least looking at the atom from its furthest electron orbit inward, yes, its mostly space, more akin to a solar system than a few billiard balls forming a core and ping pong ball electrons spinning in close orbits. the power of the atom that we use is manipulating the loose outer electrons, while the power gained from shattering the core of large atoms is still being debated...

[Tormod]

The "solar system" model of the atom is long since outdated. Rather, the electrons form shells around the nucleus at distances dictated by the energy levels of the electrons. The electron cannot be observed in orbit but the electrical charge of an atom can be easily measured (unless it is an ion, it is most likely to be neutral).

The lower the orbit, the less energy the electrons have.

In a nuclear fission bomb, a minute amount of uranium (or plutonium) is needed. But to make it explode you need to create a reaction so that the uranium atoms decay and emit neutrons to make other uranium atoms decay etc. The decay of uranium creates vast amounts of energy - when uranium is split in half, both halves repel each other with a vengeance...

To get the explosion going, you need to compress the matter at the exact same time from all sides to that the uranium reaches a critical pressure level and the fission reaction starts.

A very good explanation of this is found in David Bodanis' book "E=mc2 - a biography of the world's most famous equation".

[BlameTheEx]

Originally Posted by WebFeet

Energy has no Mass, and because of this it does not have spatial dimensions, but this does not exclude Energy from having spatial coordinates.

The combination of 2 or more of these spatial coordinates would result in a spatial dimension and the subsequent system would have Mass.

I am not sure you are right there. A photon is perhaps pure energy. It has no rest mass but it DOES have mass.

[WebFeet]

Originally Posted by BlameTheEx

I am not sure you are right there. A photon is perhaps pure energy. It has no rest mass but it DOES have mass.

The modern definition assigns every object just one mass, an invariant quantity that does not depend on velocity

If a photon has zero invariant mass, then that is how we define its mass, as zero. If it has no mass, then the only way to locate it would be with a coordinate.

[paultrr]

Photons have no rest mass. But they do have energy in the form of kenetic energy. Using the old formula E=MC^2 they still due to that kenetic energy have an energy equal to a certain amount of mass. As that matter goes there is no such thing as a photon or anything else in this universe at absolute rest. The term rest actually is itself a relative term where usually one can use the earth as a rest state against which things are measured. Something traveling at C or slightly less has more energy than something stationary, in a sence of the word, here on earth. However, the earth and the solar system itself is in motion so even here nothing is really at rest.

[WebFeet]

Originally Posted by paultrr

Photons have no rest mass. But they do have energy in the form of kenetic energy. Using the old formula E=MC^2 they still due to that kenetic energy have an energy equal to a certain amount of mass. As that matter goes there is no such thing as a photon or anything else in this universe at absolute rest. The term rest actually is itself a relative term where usually one can use the earth as a rest state against which things are measured. Something traveling at C or slightly less has more energy than something stationary, in a sence of the word, here on earth. However, the earth and the solar system itself is in motion so even here nothing is really at rest.

How can a photon have kinetic energy ?

Objects that are not in motion possess potential energy, which is converted to kinetic energy when a force acts upon the object to put it in motion. So an object in motion possess kinetic energy.

What force has acted upon a photon to put it in motion ? A photon's natural state is in motion, in fact its ONLY state is in motion, at a fixed velocity.

If a photon's velocity cannot be effected in any way, then is it really in motion ?

[Tormod]

Photons bend around gravity wells (like when a ray of light passes the sun). Photons never accellerate to the speed of light. They are light, and as such leave the emitting source at the speed of light. There is no force that has acted upon it for this to happen - all it takes is the creation of the photon (for example, when electrons change energy levels inside an atom).

The velocity of light can be changed - observe how light moves slower in water. In some experiments light has been slowed down to a few meters per second, AFAIK.

[C1ay]

Originally Posted by humility

It is that Energy does not have mass.

Take that mass you know as a baseball and hold it in your hand to get a feel for just how much mass it is. Now let a pitcher impart energy to that ball and catch it with the same hand. You will feel the new mass it has acquired from the energy. Next you will feel the energy as it changes form into heat energy in your hand.

[WebFeet]

Originally Posted by Tormod

The velocity of light can be changed - observe how light moves slower in water. In some experiments light has been slowed down to a few meters per second, AFAIK.

The speed is then dependant on the medium through which it is traveling.
In the experiment you mention,is light being slowed down or has its arrival at the end point merely been delayed?

Originally Posted by Tormod

Photons never accellerate to the speed of light. They are light, and as such leave the emitting source at the speed of light. There is no force that has acted upon it for this to happen - all it takes is the creation of the photon

Do photons get created ?
Energy can neither be created nor destroyed
Assuming a photon to be pure energy, this would imply that rather than it being created, it was there all along. Maybe as part of a more complex structure, such as the electron. If it were a component of the electron, then it would follow that it should maintain it properties while part of the electron, in other words it maintains its constant velocity within the structure of the electron. When it is released from the electron structure, it flies off at the only velocity it knows- the speed of light.
Throw an electron and a positron at each other, the result is two photons.