And there's your answer.
3 seconds sound clip from the Forbidden Planet (1956) movie soundboard.
You can hear this line at 01:19:44 in the Blu-ray version of the movie.
Quote context
[...]
- No, skipper, that is a scientific impossibility.
- Hypnotic illusions don't tear people apart.
- It would sink with its own weight to the center of this planet.
- Well, you saw it yourself, standing in those neutron beams.
- It must've been renewing its molecular structure from one microsecond to the next.
[...]