With no gravitational force to work against, your body not only doesn't need the same amount of muscle and bone, it starts breaking them down. As on Earth, so in space: use it or lose it. And exercise may not solve the problem.
No one with a living room radio that was a piece of furniture at the time would say, gee. I want to carry that around on my hip pocket. That was not a thought until NASA initiated this whole exercise. So there's an influence that's not just spinoff.
These are two different exercises. One of them is, "You don't know and I know, so just shut up and listen," and the other one is, you're curious and you're learning, and I have a way where you can learn this so you'll know it as well. And when you know it, and know why you know it, then you don't have to reference me ever again because you take ownership of the knowledge, and you can then share it with someone else.
