General rule, 1-2 orders of magnitude more sensitive than we have now.

Which is bonkers considering we’re really close to exact when we measure things like the weight of individual atoms… But we measure using things like the energy the atom releases when being smashed at close to the speed of light. All those measurements have some inaccuracy that stacks, even if the math is precise, so it’s, analogous to using 22/7 in place of pi. you need 10x more granularity to register that pi is 3.141… and not 3.142… need new inventions in the way to measure to know for sure.