# What is a constant

Could someone please explain the concept of a constant in simple terms?

It is a number that simply does not change and has a set, defined value. Pi, i (squareroot of -1) and e (Euler's number) are all examples of constants.

It's also a "fudge factor" so that our equations work out. For example, we all know E = mc2, but many physicists set c = 1 so that E = m and the fudge factor disappears. I've often wondered if it was possible to develop a mathematical/physical system where all of the fudge factors for the fundamental constants of the universe could be eliminated, but my mathematical expertise is nowhere near that sophisticated.

It depends on the context. The word "constant" have connected but different meanings in maths and in physics. As you're posting in the physics forum, I guess you're more interested with the physics notion. In a physical theory a constant is a quantity used to describe the behaviour of a system (together with plenty of other quantities) but that does not depend on which system is studied, what are its environement, the interval of time considered or the position in space of the system. So its value can be given (whithin a given system of units) independently of any experience.

By a constant i was referring to this type of constant-

F is proportional to m
F is proportional to a

Therefore F=kma
where k is the constant of proportionality

CompuChip