Interesting…. Using your argument of constructs, a meter is just a construct that enabled us to orient ourselves with respect to the position of others, (or landmarks) – yes, it was also a form of comparison for trade in commerce… but I digress. That simple “concept” has been expanded, and from...
It comes from a few different sources:
- all matter is a form of condensed energy; if you break a particle into 2 smaller particles whose net sum is less than the original, energy actually ballances out the remaining mass - it's actually converted
- as chroot said, if something already has...