Isaac Newton
This is what Newton thought about gravity.
What is, gravity is a force (that pulls on massive objects)?
This is what you would feel if you were in freefall.
What is weightless (or no forces on your body)?
This is the amount of acceleration you are currently experiencing, on the surface of the Earth.
What is 1 g?
Curved spacetime is responsible for this natural phenomenon.
What is gravity?
This is what happens to time when you get close to the surface of a large planet or star.
What is it goes slower (time dilation?
This is what Newton came up with when he watched an apple fall from a tree and looked up at the moon.
What is Newton's Law of Gravity?
This is how many g's were on Mr. Crocker's cellphone when he dropped it.
What is zero g's?
This is the general amount of acceleration you would feel in a rocket ship leaving the Earth's surface.
What is greater than 1 g?
Because spacetime is curved around the Sun, the light from distant stars, passing close to the Sun does this.
What is, it bends?
Compared to a person on the surface of a large planet, an astronaut in mostly empty space experiences time in this way.
What is, it speeds up (goes faster)?
What is, time never changes (a second is a second)?
In order for you to experience freefall in a classroom, you would simply do this.
What is remove the chair beneath your body?
If you are in a rocket ship that just turned left, away from the solar system, and the engines are still thrusting, this is the direction that is now down.
What is right?
This is the main reason our classroom's Spacetime Simulator failed to produce orbits which last a long time.
What is friction (when the marbles rolled on the fabric, there was friction)?
When people on Earth look at the clock on a spaceship which is passing by the Earth at almost the speed of light, this is what they see.
What is time moves slower on the clock (or time slows down)?
This is what Newton thought about space (or distance/length of an object).
What is space always remains the same size (it doesn't change, it is constant)?
This was Einstein's happiest thought.
What is, a person (window-washer) falling from a building would experience no forces (weightlessness) on the way down.
When you turn off your thrusters of your rocket ship you are going 100,000mph away from the solar system. In this situation, this is the direction you would think is down.
What is, there is no down (or up, you are weightless)?
This object curves spacetime so drastically that nothing that goes into its well can escape.
What is a black hole?
If you watch a super fast moving object pass you by, not only will you witness it's clocks moving slower, but the object will appear this way.
What is shorter (it's length will contract)?
Famously, Newton said this when asked how gravity actually works.
What is, I don't know (I'll leave it to those who come after me to figure it out)?
Near Earth's surface, if you are falling, you are experiencing this one force on your body.
What is air resistance (or drag)?
You are in freefall heading fast toward a crash landing on the Moon. In this scenario, this is accelerating.
What is the Moon's surface is accelerating toward you?
Because the Earth spins, it does this to spacetime.
What is frame dragging (or it pulls spacetime along with it as it spins)?
In order for GPS systems to work, these are the two things that need to be thought about when the systems are programmed.
What are Gravitational Time Dilation (General Relativity) and Mechanical Time Dilation (Special Relativity)?