Okay, this is wild: MIT scientists just captured heat literally sloshing back and forth like a wave inside a superfluid at near absolute zero. Normally, heat just spreads out slowly, but in these quantum fluids, it acts like a second kind of sound—hence the name 'second sound.' This is the first time anyone’s actually imaged it! The discovery could help crack mysteries about superconductors and even neutron stars. Physics just keeps getting weirder (and cooler). #Science #MIT #SecondSound