How is the mass defect from a nuclear reaction created?
Thanks for the help :)
Something relatively more complex emits photons and becomes relatively simpler / loses mass in the process.
Physics cannot answer "how" questions on a fundamental level.
Mass is "just" a type of energy. One type of energy is converted to a different one.
@Grinkle: fusion is a nuclear reaction as well.
mfb - good reminder, thanks.
in regards to mfb's statement about "how" statements:
i thought "why" was the question to shirk away from. i think differentiating "how" from "is" is somewhat semantic. "how" connotes an explanation, whereas "is" is book keeping; so i may venture to say that "how" is epistemological whereas "is" is ontological. but i suppose one may ask "how" ad infinitum just as one can with "why", and there seems to lie the rub.
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