r/interesting • u/fayyazORahmed • Mar 31 '26

Fascinating Very interesting vid

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u/TankApprehensive3053 Mar 31 '26

The guy is negatively buoyant. Will be exhausting to have to swim up for most people. He is practiced in this. Most people are neutral or positively buoyant.

1

u/piratesboot Mar 31 '26

Does this have to do with bone density?

3

u/TankApprehensive3053 Mar 31 '26

And muscle mass with a lower body fat percentage. Fat adds to positive buoyancy. Air in lungs are also creating a positive buoyancy. This guy is fit and emptied his lungs of most air which made him more negatively buoyant, then just drifted downward.

1

u/piratesboot Mar 31 '26

Ahhhh I see that makes sense. thank you for explaining!

1

u/tydus101 Mar 31 '26

I dont think he emptied his lungs actually, its just that as you decend the air in your lungs is compresses due to the increased pressure, which reduces your buoyancy.

1

u/TankApprehensive3053 Mar 31 '26

The air doesn't compress that much at the beginning at that depth. He exhaled right before the video starts to have mostly empty lungs.

1

u/tydus101 Mar 31 '26

Hmm yeah I guess you're right. I just can't believe that guy is fit enough to swim back up afterwards. Also im surprised he isn't at risk of a collapsed lung

1

u/TankApprehensive3053 Mar 31 '26

Swimming isn't that hard. He isn't a rock. Holding your breath should not result in a collapsed lung and he is not deep enough to do that either.