Therefore the Falling Hazard

What the 181 thinks about geodesic domes:
We think about how the term “geodesic” gets used in physics, particularly in relativity: when you think of a straight line in the middle of space, you might imagine that if some object were at one end of this imaginary line and somebody gave it a thwack, this object would travel in a straight line to some other point. Think about when you get away from earth and get away from earth’s gravity (and maybe also you have to imagine that you get as far away as possible from any other existing objects).

If now in this situation, when you are as far away from any other objects as you can possibly get, if you got a bump or a kick and moved out into this empty region then you could, maybe, call it intuitive that it would be a straight line that you travel in, because you go in a direction and you keep going in that direction.

It depends on what you like to feel like, we guess. Imagine that you are in a car going down a straight smooth road and your eyes are closed and you can’t hear the sound of the car engine and the windows are rolled up and maybe you even have earplugs in and your eyes are even covered—in this situation it’s going to be really hard to tell the difference between 100 miles per hour and 50 miles per hour. As long as you are going straight. But if you go around a curve, 100 miles per hour feels very different from 50 miles per hour. And this is a long way of saying that the straight line path, without the curves, is a geodesic.

In other words you can determine a geodesic by how you feel traveling along it, as long as you eliminate your connection with other points of reference (which are really arbitrary, on earth you might use a tree as reference for your speed, “that tree went by quickly, I must be going fast!’ But in outer space if it’s you and a tree who’s to say who is going fast? It is very hard to tell.)

Now we are again imagining that we are in space. In space and in orbit around some massive object—let’s say it’s a black hole. Nothing else is around. You will orbit the black hole and you feel exactly like you are stationary. To someone observing the situation, they would say “that person is not going in a straight line, they are traveling in an ellipse (or something like an ellipse).” But the person themselves will say, “I am going straight, I feel no effects of speed, acceleration, etc. I could be motionless.” One should probably call orbital motion straight line motion, but that’s confusing, consequently there’s a different term for it: you call it a geodesic. So geodesic can be any path where one physiologically feels motionless.