Why can't we define fundamental unit of mass?
86783
Why do we still not have an exact (constants-based) definition for a kilogram?
146976
Is the gravitational constant $G$ a fundamental universal constant?
68831
Why mass terms are forbidden?
8758
Why isn't the product rule used in the definition of mechanical work?
5388
Are Newton's "laws" of motion laws or definitions of force and mass?
143165
Why are angles dimensionless and quantities such as length not?
155640
Why is the laboratory frame energy always greater than the center of mass frame energy?
46149
Units of a log of a physical quantity
26085
Why is the action dimensionless in natural units?
47638
Mass and Newton's Second Law
123058
Can units be plural?
45283
Why don't virtual particles violate conservation of mass/energy?
22090
Does the (relativistic) mass change? Why?
15971
Are units of angle really dimensionless?
94442
Fundamental particles identical or just differences very small?
22182
why don't we define vector multiplication component-wise?
53259
Do photons have mass?