how some fish species can live at insane depths of the ocean, while the best nuclear submarines can only go a couple thousand feet before being crushed.

Question

Soft bodied fish like the snail fish can apparently live at depths deeper than 25,000 feet… yet somehow, despite modern engineering marvels, and the availability of the strongest materials available to man, we can barely create underwater vehicles that dive to the same depths — and even the ones that do, are far from safe. How do these submarines get crushed and these soft bodied fish survive?

In: 2

Answer 1

It’s not the pressure that’s the problem; it’s the pressure *difference* that’s the problem. Submarines have hollow, low-pressure air-filled spaces inside them; the fish don’t. The submarines must maintain their low pressure spaces through the sheer strength of their mechanical structure; the fish do not face this challenge because they simply have the same pressure inside and out. This wouldn’t be a problem for humans either if we could fill our hollow spaces with liquid—but that tends to hamper our ability to breathe.