Adam Brown

Most chemical reactions are pretty inefficient.

You burn gasoline and you extract, as a function of the rest mass of the gasoline that you started with, you extract one part in 10 billion of energy from the gasoline that you started with.

So that's bad from the point of view, you know, you have MC squared worth in a gallon of gasoline, you've got a full MC squared worth of energy in there, and you can only get out one part in 10 to the 10.

That's a pretty unsatisfactory...

situation, roughly speaking the reason that all chemical processes are so inefficient is that they only address the electromagnetic energy in the electrons, and a very small fraction of the electromagnetic energy in atoms is stored in the electromagnetic interaction between the electrons and between the nucleus and the electrons.

Most of it is stored in the nucleus itself, in the strong nuclear forces, and particularly in the rest mass of the protons and neutrons that constitute it.

So you can do much better if instead of doing electromagnetic interactions you use nuclear interactions that can probe the energy in turning protons into neutrons.

That's why nuclear power plants are so much more efficient on a per-mass basis than chemical

power plants like coal plants or gas plants, because you're getting a much higher fraction.

Best case scenario, you're getting one part in 10 to the 3 or 10 to the 4 of the rest mass of the uranium that you start with.

You're extracting as energy.

But even there, even in that process, it's still only absolute best one part in 1,000 of the rest mass.

And the reason is that you are...

Using where much more of the energy is stored, which is the strong and weak interactions between the protons and the neutrons, so much more is available to you.

But still, at the end of whatever the process you finish with there, there's a number that'll be conserved.

And that is what's called the baryon number.

So it's the total number of protons plus the total number of neutrons.

You can transmute protons into neutrons or vice versa in nuclear processes, which is part of the reason there's so much more...

use much more better energy than things that just affect the chemistry.

But still, most of the energy is stored in the rest mass of the protons and the neutrons.