Wasn't it Einstein that said that mass is just energy?
How did it go?
E = m c^2
The faster you go, the more energy... and the more mass your thing carries.
That 'm' in there is special. It's the so-called relativistic mass.
m = m0 / sqrt(1 - v^2/c^2)
With m0 being the mass of the object, at rest.
v is the object's speed and c is the good old constant... oh... wait... no... it's a speed... the speed of electromagnetic waves (light) - for relativity came out of trying to figure out the relative motion of electromagnetic waves, as described by Maxwell's equations.
What happens when v becomes c? square-root of zero on the denominator? zero on the denominator?! ARHGHGHG
You get a poorly behaved equation... we don't like dividing by zero... nor does nature... But Nature cheats, it seems - and sets the mass of the electromagnetic wave at zero, too.
What happens if you get something with a v greater than c? square-root of a negative number? An imaginary number? Imaginary mass?
Ai ai ai!
How did it go?
E = m c^2
The faster you go, the more energy... and the more mass your thing carries.
That 'm' in there is special. It's the so-called relativistic mass.
m = m0 / sqrt(1 - v^2/c^2)
With m0 being the mass of the object, at rest.
v is the object's speed and c is the good old constant... oh... wait... no... it's a speed... the speed of electromagnetic waves (light) - for relativity came out of trying to figure out the relative motion of electromagnetic waves, as described by Maxwell's equations.
What happens when v becomes c? square-root of zero on the denominator? zero on the denominator?! ARHGHGHG
You get a poorly behaved equation... we don't like dividing by zero... nor does nature... But Nature cheats, it seems - and sets the mass of the electromagnetic wave at zero, too.
What happens if you get something with a v greater than c? square-root of a negative number? An imaginary number? Imaginary mass?
Ai ai ai!
