Part 3/9:
The speaker casually transitioned into a discussion about the Ultra experiment, which originated from an unexpected discovery while testing indium for weak interactions in a cavitation system. Indium was chosen for its properties as a neutron absorber, similar to gold, and its favorable beta isotopes. This initiative was part of a broader exploration to observe weak interactions in materials, ultimately leading to the development and demonstration of the Ultra experiment. This simple yet repeatable demonstration of fundamental physical processes became a focal point of the talk.