[user11]

Hi, I'm amazed by all the tools we have in science to measure things indirectly fx measure weight(force) by measuring mass and downward acceleration of an object.

But there seems to be some hidden secrets: How do you invent a concept like mass and force and measure them in the first place? We know that you need force and acceleration to measure mass, but to make equipement like a newton meter to measure force, you need a known mass to calibrate it to measure force accurately. which invention came first, and how could you define the size of one of them without knowing the other?

[mizzo.pl]

Mass as weight goes back well in pre-history. While actual as more scientific goes back to Newton I think, and that gravitation stuff. About thinking out the concept? It's like going deep in asking why. If I push block it gets pushed. Why? Because I pushed it. But why pushing it caused it to move? And so on in that chain of thinking and trying to answer it with scientific answers rather than just because it does, and that's all.