[TheOtherHobbes]

There's no such thing as "conservation of matter." There's conservation of mass in basic chemistry, but it's really just a partial understanding of conservation of energy anyway.

It's almost as if the author has never heard of exothermic chemical reactions.

[kmm]

Conservation of matter is as exact a law as they come in chemistry, let alone biology. The part of mass lost as heat doesn't even match up one part in a billionth. As soon as it becomes relevant, you're not doing chemistry anymore, you're doing physics.

I know it's not "technically" correct, but when doing science, you use the laws applicable to whatever field you're working in.

[ncmncm]

In biology, there is conservation of matter. Geology, too. Everywhere, really, except in atom-smashers, stellar cores, and nukes.

[doublesCs]

No, this isn't true. There's no conservation of matter anywhere. If you take 2 hydrogen atoms and weight them, then bond them together in a hydrogen molecule and weight that, the molecule weights less than twice one hydrogen atom.

[ncmncm]

But you still have the two hydrogen atoms, before and after. They are matter. Tiny (really tiny!) differences in weight don't change that.

[doublesCs]

I guess when you said "conservation of matter" I interpreted that as meaning "conservation of mass", seeing as we're talking about weight loss.