All of those things fall out from the speed of light being independent of the speed you are moving at (i.e. regardless of how fast or slow or what direction you

All of those things fall out from the speed of light being independent of the speed you are moving at (i.e. regardless of how fast or slow or what direction you are going, you will always get the same answer when you measure the speed of light in a vacuum). The easiest one to explain is probably the most mind-bending: wheter or not an event is "simultaneous" depends on the frame of reference. You are sitting in a spaceship that has a large empty cargo bay. There is a lightbulb in the exact center of the cargo bay. If you turn the bulb on, it will hit the front and the rear of the cargo bay at the exact same time. This is true regardless of the speed the spaceship is traveling at (because the speed of light will always be measured as the same value). Now think of what happens from the frame of reference of someone on a planet as the spaceship is passing by. Since the spaceship is moving forwards, and the light moves in both directions at the same speed, the light will hit the back of the cargo bay slightly before the light hits the front of the cargo bay. The faster the spaceship is moving, the bigger this difference.