3 ms·

Right, I wasn't saying he did. I was trying to say that, without a theoretical framework to hang that kind of energy generation on, there was no capacity to und

Right, I wasn't saying he did. I was trying to say that, without a theoretical framework to hang that kind of energy generation on, there was no capacity to understand what was going on. E=MC^2 is precisely that kind of theoretical framework. Pretty amazing, to me. Being able to say "It's this far away, this hot, and this large, but why?"

fsh 7y ago
E=mc^2 is a consequence from special relativity, not a theoretical framework. It also has very little to do with the understand of nuclear reactions. The reason why nuclear reactions release much more energy than chemical reactions is that the binding energies inside the nucleus are much larger than inside the electron shell. Mass-energy equivalence exists in both cases.
- pfdietz 7y ago
  Indeed. And in a Newtonian universe, it's possible that something like nuclear fusion could exist that would liberate much more than mc^2. There would be no upper limit on nuclear reaction energies set by the total rest energy of the reactants.
archgoon 7y ago
I don't think thats true though. In 1903, Radioactivity had already been proposed as an explanation for the Sun's heat (2 years prior to Annus Mirabilis). The connection between E=mc^2 and nuclear reactions doesn't become clear until you start losing mass (proton + neutron) in the reactions, which doesn't happen for the reactions involved in the Sun (Carbon Nitrogen Oxygen Cycle). The connection was recognized by Lise Meitner and Otto Hahn when they discovered fission, where a mass loss does occur. However, they didn't publish their discovery until January 1939; and Hans Bethe had already been working on the Carbon Nitrogen Oxygen Cycle, and didn't need fission to account for the Sun's processes (neutron + proton mass is conserved in the relevant reactions). He was just working off of observed empirical data to make his conclusions.
- the8472 7y ago
  > which doesn't happen for the reactions involved in the Sun You might want to rephrase that, after all a mass loss occurs in any reaction, it's just not as significant as a whole nucleon.

fsh 7y ago

E=mc^2 is a consequence from special relativity, not a theoretical framework. It also has very little to do with the understand of nuclear reactions. The reason why nuclear reactions release much more energy than chemical reactions is that the binding energies inside the nucleus are much larger than inside the electron shell. Mass-energy equivalence exists in both cases.

pfdietz 7y ago
Indeed. And in a Newtonian universe, it's possible that something like nuclear fusion could exist that would liberate much more than mc^2. There would be no upper limit on nuclear reaction energies set by the total rest energy of the reactants.

archgoon 7y ago

I don't think thats true though. In 1903, Radioactivity had already been proposed as an explanation for the Sun's heat (2 years prior to Annus Mirabilis). The connection between E=mc^2 and nuclear reactions doesn't become clear until you start losing mass (proton + neutron) in the reactions, which doesn't happen for the reactions involved in the Sun (Carbon Nitrogen Oxygen Cycle). The connection was recognized by Lise Meitner and Otto Hahn when they discovered fission, where a mass loss does occur. However, they didn't publish their discovery until January 1939; and Hans Bethe had already been working on the Carbon Nitrogen Oxygen Cycle, and didn't need fission to account for the Sun's processes (neutron + proton mass is conserved in the relevant reactions). He was just working off of observed empirical data to make his conclusions.

the8472 7y ago
> which doesn't happen for the reactions involved in the Sun You might want to rephrase that, after all a mass loss occurs in any reaction, it's just not as significant as a whole nucleon.