At the moment, I'd say my ideas on the subject are very FMA, although the idea of equivalent exchange has been with me for a lot longer than the show has. I'm open to new interpretations, but I view it as turning something into something that's worth the same.
That interpretation does not seem clear to me, considering that the value of things is subjective. Unless the measure is energy or something of the sort, it seems like mambo jambo to me! :P
Besides, the whole point of alchemy is to get something that has more value than what you previously had. Also, I haven't actually read/watched FMA, so I wouldn't really know its interpretation, except perhaps for the fact that it is probably quite imaginative.
This... is the FMA way. :P
Well, it seems to me that the only objective way (unless I'm missing something) would be that the original material and the product should be equivalent in their total mass-energy.
I don't think you're missing anything, but we're going to have to figure out what transmuted objects should be equal in. There's... hmm...
Not mass, because you could have a plastic folder and turn it into it's weight in platinum, which would probably be worth a lot more.
Not materials, because then you wouldn't really be able to turn anything into anything else so much as reconstruct something. Though that could be a step in the process...?
Maybe energy... I mean, some objects don't have any energy, so they couldn't be changed... if that were the case, then something like a nuclear fuel rod would become really valuble.
Ugh... my brain's starting to hurt. :P