Second Sound Captured: Physics Breakthrough
- In a groundbreaking achievement, scientists have, for the first time, directly imaged "second sound," a phenomenon where heat behaves like sound waves.The observation, made within a superfluid state...
- This breakthrough, achieved using a novel heat-mapping technique, could provide insights into heat flow within ultradense neutron stars and advance the advancement of high-temperature superconductors.These superconductors, a major...
- richard Fletcher, an assistant professor of physics at MIT and study co-author, likened the phenomenon to heat sloshing back and forth in a tank of water, even as...
Scientists have achieved a monumental feat: directly imaging “second sound,” a phenomenon where heat acts like a wave, for the first time. This observation,made in a superfluid state using cold lithium-6 atoms,marks a pivotal breakthrough in physics.This innovative heat-mapping technique allows visualization of heat waves, offering invaluable insights into superconductors adn the behavior of neutron stars. This advancement, led by MIT researchers, is poised to revolutionize our understanding of heat flow in extreme environments, opening doors to advancements in energy transmission and astrophysics.The implications span from improving high-temperature superconductors to more accurately predicting neutron star behavior, a major goal in physics. Discover how News Directory 3 is following the progress, and find out what’s expected to come next in this groundbreaking research.
‘Second Sound’ Captured: Scientists Image Heat Waves in Superfluid
updated may 30, 2025
In a groundbreaking achievement, scientists have, for the first time, directly imaged ”second sound,” a phenomenon where heat behaves like sound waves.The observation, made within a superfluid state of cold lithium-6 atoms, reveals heat moving as a wave and bouncing within its container.
This breakthrough, achieved using a novel heat-mapping technique, could provide insights into heat flow within ultradense neutron stars and advance the advancement of high-temperature superconductors.These superconductors, a major goal in physics, promise near-lossless energy transmission.
richard Fletcher, an assistant professor of physics at MIT and study co-author, likened the phenomenon to heat sloshing back and forth in a tank of water, even as the water itself appears still.
Typically, heat dissipates slowly from a source, raising the temperature across a material.Though, superfluids, created by cooling fermions to near absolute zero, defy this norm. Atoms pair up and move without friction, causing heat to flow like a sound wave.
Physicist László Tisza first predicted this “second sound” in 1938. However, direct observation has been elusive until now.
Martin Zwierlein, a physics professor at MIT and senior author, noted that previous observations only detected faint reflections of density ripples associated with second sound. The new technique allows for direct observation and characterization of the heat wave.
The researchers overcame the challenge of tracking heat flow in ultracold gases, which do not emit infrared radiation. Thay developed a method to track fermion pairs through their resonant frequencies. As lithium-6 atoms change temperature, their resonant radio frequencies shift, with warmer atoms vibrating at higher frequencies. By applying resonant radio frequencies, the scientists tracked the particles’ flow frame by frame.
Zwierlein stated that this new technique allows them to observe the transition from a normal fluid, where heat equilibrates predictably, to a superfluid, where heat sloshes back and forth.
the physicists believe this technique will enable better study of extreme objects like neutron stars and improve the design of high-temperature superconductors.
“There are strong connections between our puff of gas,which is a million times thinner then air,and the behavior of electrons in high-temperature superconductors,and even neutrons in ultradense neutron stars,” Zwierlein said.
What’s next
The researchers plan to use their heat-mapping technique to further explore the properties of superfluids and their potential applications in energy transmission and astrophysics.