I don’t know either, but I do know that an internalised, correct understanding of pressure and one of its measures ‘pounds per square inch’ would be a sufficient condition to save his life.
I think this is a good opportunity to point out that many people haven’t internalized what it means to say “the atmosphere’s pressure is about 15 psi”. It implies that, if you were to lie face down and someone like me stood on your back, eliciting excruciating, “GET OFF ME!” pain on your end, they’ve only increased the pressure on your back by maybe 30% of what was on it your entire life, even as it may seem like much more than that.
Indeed, when I visited the Boston LW meetup, a few people there initially refused to believe the implications of 15 psi atmospheric pressure, apparently never having connected that figure to everyday experience.
Fortunately, there are easy experiments to impress people with. As a kid, my favorite one was laying a ruler on a table so half of it was sticking out perpendicularly, put a few layers of newspaper over the other half, and then quickly hit the exposed half downwards—and fail to knock it off the table because atmospheric pressure helped hold it down.
(At least, I think this is how it went. It was a long time ago. I’m sure there are other nifty experiments.)
I think this is a good opportunity to point out that many people haven’t internalized what it means to say “the atmosphere’s pressure is about 15 psi”. It implies that, if you were to lie face down and someone like me stood on your back, eliciting excruciating, “GET OFF ME!” pain on your end, they’ve only increased the pressure on your back by maybe 30% of what was on it your entire life, even as it may seem like much more than that.
Indeed, when I visited the Boston LW meetup, a few people there initially refused to believe the implications of 15 psi atmospheric pressure, apparently never having connected that figure to everyday experience.
Fortunately, there are easy experiments to impress people with. As a kid, my favorite one was laying a ruler on a table so half of it was sticking out perpendicularly, put a few layers of newspaper over the other half, and then quickly hit the exposed half downwards—and fail to knock it off the table because atmospheric pressure helped hold it down.
(At least, I think this is how it went. It was a long time ago. I’m sure there are other nifty experiments.)