There is no way to convert between energy and matter. Thinking that E=mc^2 is an "exchange rate" between energy and matter is a common misconception.
The meaning of E=mc^2 is not that you can exchange E amount of energy for mc^2 amount of mass. The meaning of E=mc^2 is that in every system, the total kinetic energy is equal to the the total mass times the speed of light squared.
The common belief is: When you cause nuclear fission in an atom, that very small mass gets converted into energy, and because the exchange ratio is c^2 (which is enormous), the lost mass turns into a huge amount of energy, which is the nuclear explosion.
This is wrong. The correct explanation is: Because of E=mc^2, we know that even in a small atom there is a huge amount of energy. That energy then gets converted using fission into a more useful form (the explosion.) The mass of the whole system stays constant through the whole process.
Well, no, that's not the answer. It's not important how the mass is transformed into energy, nor how much. He's just saying that if it's possible to transform x kg of something into y energy and back again (the second part being the real challenge), could I make a machine that "creates" energy?
From Wikipedia:
"The total rest masses of the fission products (Mp) from a single reaction is less than the mass of the original fuel nucleus (M). The excess mass Δm = M – Mp is the invariant mass of the energy that is released as photons (gamma rays) and kinetic energy of the fission fragments, according to the mass-energy equivalence formula E = mc²."
So the energy released by the reaction would be Δmc², right?
It says "the total rest masses." This is talking about the rest mass, which is different than the relativistic mass. I believe that the relativistic mass is the one that actually matters.
To your question, I agree that the energy released would be Δmc², but there would be no conversion between mass and energy in the process. The total mass and the total kinetic energy would remain the same after the fission as they were before it.
Ah, so once the byproducts are again at rest with 0 kinetic energy, total mass of the system will be equal to total mass of the system before?
So the energy of the explosion comes purely from the atoms being at a lower energy state than they were as uranium? I suppose it makes sense if it takes a huge outlay of energy to form them, which stars could certainly source.
There is no way to convert between energy and matter. Thinking that E=mc^2 is an "exchange rate" between energy and matter is a common misconception.
The meaning of E=mc^2 is not that you can exchange E amount of energy for mc^2 amount of mass. The meaning of E=mc^2 is that in every system, the total kinetic energy is equal to the the total mass times the speed of light squared.
The common belief is: When you cause nuclear fission in an atom, that very small mass gets converted into energy, and because the exchange ratio is c^2 (which is enormous), the lost mass turns into a huge amount of energy, which is the nuclear explosion.
This is wrong. The correct explanation is: Because of E=mc^2, we know that even in a small atom there is a huge amount of energy. That energy then gets converted using fission into a more useful form (the explosion.) The mass of the whole system stays constant through the whole process.