Einstein and Newton are in a bar...
...Einstein says to Newton, "I've found mathematically that as an object travels faster and faster, it experiences time lower and is squished in the direction parallel to the velocity, when viewed from a stationary perspective."
Newton replies "Interesting. Well, do go on."
Einstein explains, "Imagine two people at opposite ends on top of a train moving very quickly. Even though the train is moving, if the person in the rear shines a light to the other in the front, they will measure the light to move at the usual constant speed of light. Likewise though, a person stationary beside the tracks will also measure the light to travel at the same speed, though from their stationary perspective the light traveled further because by the time the light got to the front person, they had moved a little bit more forward due to the velocity of the train. This means that the stationary person sees the light take longer to go from one person to the other."
He adds, "Additionally, if the person in the rear of the train measures the velocity of the light away from him to be one value, shouldn't the velocity they themselves possesses not mean that the light would move faster from getting that extra push? But when we measure it, this is not the case!"
"If we allow ourselves to alter values like the passage of time for different perspectives, and even the masses of objects, we can create a set of physical laws which shows us how the people on the train can reconcile their views with the person beside it, based upon their relative velocities."
And so Newton replies, "What the hell is a train?"
