When whales collapse their lungs there is still lung matter present. Why doesn't that get crushed?

Thank you for sending in such a great question!

Thank you for this very interesting question!  It is such a good question, as I am not sure scientists know the answer to it yet. Some of the most loved creatures on the planet still have many secrets for us to uncover and whales are certainly one of them, as it can be hard to study their behaviour.  I found this article on the London Natural History Museum website that I think could be of interest to you: https://www.nhm.ac.uk/discover/secrets-of-deep-diving-whales.html.  

For instance, when talking about the potential for whales to collapse their lungs as a way of coping with deep dives, they say this about the issues that come with this process:

“It is not fully understood how whales deal with these problems, as they too are at risk of their body tissues becoming heavily saturated with harmful levels of nitrogen.  
One theory is that marine mammals collapse their lungs in a way that forces air away from the alveoli, the tiny air sacs in the lungs that transfer gasses like oxygen and nitrogen into the blood.”

I am sorry that I cannot yet answer your question in more detail but I hope this article helps, and perhaps you will enjoy reading my answer to a question about ocean pressure more generally, linked here: https://www.ucl.ac.uk/culture-online/case-studies/2021/apr/how-much-pressure-builds-deepest-point-ocean.

Thank you again for the brilliant question!  One of the great things about being a scientist is finding the questions we don’t know the answers to yet, to try and then work to answer them.