You certainly know it, but sharing it for the ones who don’t:
The full equation is E² =(pc)² +(m₀c²)² where E, p, c, m₀ are respectively: energy, momentum, the speed of light, inertial mass. The (pc)² part is kind of a big deal, because otherwise massless particles (like photons) would have no energy.
If p = 0, then the equation simplifies into that famous E=mc².
This, too: if E = hc/λ and E = mc², then we can combine both as hc/λ = mc². Rearranging this shit you get m = h/λc. Since h/c = 2.2*10⁻⁴²kg*m, you’d get:
The famous equation includes momentum so I always chuckle when they only show E=mc2
You certainly know it, but sharing it for the ones who don’t:
The full equation is
E² = (pc)² + (m₀c²)²where E, p, c, m₀ are respectively: energy, momentum, the speed of light, inertial mass. The(pc)²part is kind of a big deal, because otherwise massless particles (like photons) would have no energy.If p = 0, then the equation simplifies into that famous E=mc².
What I think is funny is that if you assumed E=mc^2 for all particles, then that would mean that red light is lighter than blue light.
This, too: if E = hc/λ and E = mc², then we can combine both as hc/λ = mc². Rearranging this shit you get m = h/λc. Since h/c = 2.2*10⁻⁴²kg*m, you’d get:
…BLOODY ULTRAVIOLET IS MAKING ME FAT!
Einstein initially did write:
Does the inertia of a body depend upon its energy-content?, 1905
which got re-arranged to E=mc^2. Although he was aware that this doesn’t apply to systems in motion or mass-less particles such as photons.