There is an element of science fiction in Einstein's thought experiments. He said, "Imagination is more important than knowledge." He certainly built upon Newton, Maxwell, Kelvin , & others.

But I still haven't figured out what C2 really means. Is this just a mathematical constant used to describe reactions of annihilation & conversion or is there something of that speed actually happening?

You say C2 represents light moving away from each other. I assume you mean the photons (actually waves) seperating in an interaction that involves the conversion between mass & anti mass, although some physicists doubt such a process exists. But do they actually do this conversion at C2

@Remiforce C is the speed of light, emanating from a source (like the Sun) With E=mc2 - its explaining the release of Energy from a single point, hence light is emanating in all directions. That's why he put the 2 - to represent the speed of light times 2.(North/South)
Ive found that most of Einsteins work to be nonsense. His special Theory claims time is effected by gravity - it isn't. Gravity is created by matter, and only effects matter.

@Remiforce Considering C squared would be an enormous number, I think E =MC2 would be more accurate - 2 times the speed of light.

Thanks for your elucidation of the problem. As I understand it, mass is not matter, as it depends on relative velocity.. The conversion of mass & energy seems to be defined by the constant of C2,, but is this just an emperical relationship or based on necessity.

Some interesting questions have come up during this discussion, such as the relation of anti matter to matter & anti energy to energy. I know these are debatable theoretical concepts, but what role does annihilation play in this mass-energy conversion process, if any.

Then we come to the nature of mass & energy. String theorists say they are states of vibration in the field, but what is the nature of this field, & does it exist in reality or just in consciousness.

& lets not get into the singularity of black holes, which may not even exist...

You can see how an interested layman like me can be confused by all this

@Remiforce There is a reason that it took 200 years to move from newtonian Physics to general relativity. Mass is best understood as weight as compared to water. The theory relates to how energy and matter are related in the universe. If you take one gram of matter (solid, liquid, gas, it doesn't matter) and totally deconstruct it so that it is totally converted into energy, that is what the theory applies to. This is at the atomic level, no atoms or particles are left. To give you an idea of why this matters, if you take a piece of wood, burn it until it is only ash, if you weigh the gas produced and the ash, it will weigh the same as before you started in spite of large amount of energy produced. Nagasaki was the result of less than 2 kilograms of matter being converted into energy if I remember right, it may have been less.

Do not try to reconcile general and special relativity with string theory, they have spent over 100 years trying to do that with very little headway. E=MC2 has been proven to be correct in applied physics. I would sstill suggest trying to locate some of Isaac Asimov's physics texts, He is probably the easiest physicist to understand.

@remiforce @glennlab Only a minute fraction of the uranium in the atom bombs got converted into energy. The atoms that were split generated other nuclei known as daughter products. All the energy derived from conversion of the rest mass of the nuclei, and the subsequent decay processes.

Elements like uranium seek a ratio or balance in the number of neutrons to protons. In this case, 143 neutrons to 92 protons. However, in a fission reaction, the splitting is uncontrolled as the high-speed neutrons bash the nuclei into fragments. Usually, the daughter nuclei have too many neutrons and decay by emitting electrons. This decay converts a neutron to a proton, getting the nucleus closer to the ideal ratio.

However, if the daughter nucleus happens to have too many protons to neutrons (less likely, but it happens) then the decay mechanism is to emit a positron, converting a proton to a neutron and moving the nucleus closer to the ideal balance. The emitted positron is a positively charged electron, an opposite to an electron, as far as charge is concerned. When the positron encounters an electron, the charges cancel and both particles are converted into a great deal of energy.

Because conventional matter is mostly expressed with electrons orbiting nuclei, an emitted electron can travel several feet before it slows down and dumps its energy into its surroundings. In contrast, a positron annihilates almost immediately given the abundance of electrons it can encounter. As noted, the entire rest mass of both electron and positron are converted to either 2 or 3 high energy photons. As the rest masses of both electron and positron are 511 keV, the total energy is 1022 keV. Thus the 2 emittted photons are 511 keV, or if 3 are emitted, 341 keV.

@racocn8 Normal radioactive decay only releases mininsule and mostly unmeasureable matter to energy conversions, it is only through fission that we are able to get a measureable amount of matter conversion, Hiroshima bomb (16 kilotons of energy) was a conversion of approx 700 milligram of U-235 the Tzar Bomba converted just over 2 kilograms.
While you explanation is good it has little to do with the enerrgy released by breaking the nuclear forces holding nuclei together. or for that matter the fusion that boosts almost all current weapons.

@remiforce @glennlab Fission does indeed release large amounts of energy; that's what nuclear energy is all about. However, the conversions you cite relate to the fissile material that converted to radioactive daughter nuclei, not the 'mass' converted to energy.

The Hiroshima Bomb liberated 6.3x10^13 joules of energy, while a proton is the equivalent of 1.5x10^-10 joules of energy. Dividing, we get 4.2x10^23 protons or AMU, atomic mass units for the bomb. A mole is 6.23x10^23 units. so the energy of the Hiroshima bomb is 4.2/6.23 moles of hydrogen. At 1 gram per mole of hydrogen, that's about 0.7 grams, or the mass of 2 paperclips converted to energy in the Hiroshima Bomb.

It is indeed surprising that the energy from a nuclear bomb can create a plasma that would briefly be suitable for fusion. This fusion then unleashes still more energy via a different mechanism than fission. And yet, the mechanism is the same as far as converting the differences in nuclear rest mass to energy

Thank you for your elucidation of the problem. What I understand is we have to square the C because that is what is indicated in emperical measurements. The theory must follow the facts. I wonder if it is known from a theoretical basis why this squaring is necessary?.

It seems interesting the numbers don't match exactly, & apparently we have missing terms that are elucidated but are much too classified to teach in public schools.

What do you mean by that? Salt is essential for life, but too much of it will get you pickled

@Remiforce i mean, don't take uninformed opinions with a grain of salt, take em with a LOT of salt. i may be wrong, but i doubt anyone here is even remotely qualified to comment on the details of einsteins work in relation to the education level of most of the members here.

@MarkiusMahamius Au contraire, maybe I am a naive layman, but I am impressed with the scientific knowledge of many of the people commenting. This seems an interesting & enlightening discussion.

True. It seems easy to confuse mass & matter, as we live in a relatively stationary world & often fail to realize mass depends on velocity

If we think of matter as fields, then it seems we do have a philosophical controversy. If we think of fields as the substrate of matter, then we are on the border between matter & energy & perhaps are leaving physics & entering metaphysics.I believe string theory posits mass & energy are based on vibrations in the field, But what is the field & how are these vibrations generated?

The distinction between matter & anti matter is old fashioned, but the concept of annihilation seems to have no relevance to mass-energy equivalence. . I think we know what happens but not how it. happens.

So as I understand it the speed of light is just a constant & not the actual speed. Mass is not equivalent to matter, as it depends on the speed. We are dealing with theoretical reality & not actual reality. Thanks for making it clear

@Remiforce I'd say that it is both it's speed and a constant. The constant is (as far as we know) the fastest anything can travel through space. Light travels at maximum speed, but I don't doubt that there are factors that can affect it.

I understand that too, but Einstein's work laid the theoretical basis for the atom bomb

So the speed of light is just a constant & not the actual speed, but why is it squared? Multiplying 186.282 mps by itself would create a tremendously high number. Why is this squaring necessary?

I am asking because I haven't had a chance to study theoretical physics to the depth I would like to, & I wonder about these things

@Remiforce Most of this is WAY over my head. I just try to glean what I can to understand as much as possible. Did you read the link I posted? The comments from people who have a much better grasp on this were helpful to me in understanding that this equation is basically showing that energy and mass are the same thing; and it demonstrates how much energy it takes to create any given amount of mass--which is a tremendous amount. At least this is my rudimentary understanding.

I just had a thought. The mass of something will vary depending on the object, but the speed of light squared will be constant. Now, why it is squared and say, not to the 3rd power, is for more capable minds than mine to understand .