## If you’re in a diving pool 3 meters deep, why do your ears hurt if you swim to the bottom?

Okay I actually know it’s the density of the water, but you wouldn’t think the pressure difference would be that great in only 3 meters, how great is the pressure difference and do you have a basic rule of thumb for how to think about that? Like I’m sure you could give me a formula that would make my eyes glaze over, so please don’t give me a scary formula, like I don’t know what a pascal is…

## Answers ( 2 )

The rate of change of pressure is the issue.

When you climb a mountain your ears have plenty of time to adjust.

If you go up in a car the ears pop every so often.

The pressure gain in just 3 meters is similar to the drop in pressure climbing to some 5000 m altitude.

Now it is tough enough coping at this altitude but imagine if you got there in just a half a second.

When physicists say there is a so-and-so chance that a particle is in a particular place, do they mean…

1) that the particle has an exact location, but the best they can do with their crude measurements is to calculate the chance that it is in any place in particular

or

2) that the particle’s position is literally a fuzzy zone of chance with no absolute position

or

3) something else?

This also (of course) applies for speed, but I don’t want to confuse things…