Re: How does ultrasound generate heat?

Physics Question ID Number: 1293658442.Ph

What is the mechanism by which ultrasound generates heat?

Greetings Green:

Reference 1. The first-ever phonon laser—a device that uses phonons, or the smallest
discrete (quantized) unit of vibrational energy—has been created by German and U.S.
scientists. The phonon laser uses amplified sound instead of light.

http://www.itwire.com/science- news/energy/27558-first-phonon-sound-laser-created-at-max-planck- institute

When atoms and molecules are at or near absolute zero temperature they have almost no
vibration. Quantum Mechanics teaches us that they cannot have zero vibration, however;
practically for us they are at zero vibration. As molecules and atoms begin to vibrate
from outside forces they impact each other causing a friction type of energy. We call
this frictional energy heat.

Recently (2010) in Germany at the Max Planck Institute, it has been demonstrated that
heat energy packets that we have been calling Phonons are quantized into energy packets.
These phonons are quantized into a frequency of vibration and an energy of vibration.
These energy packets are quantized in a manner similar to photons of light.(See Reference 1)

The water molecule is a good example of the change of state when molecules change
from solid to liquid to gas as the phonon frequency and energy of vibration increase.
We measure this change in energy as temperature.

Ultrasound wave energy (phonons)injected into a substance cause the substance’s molecules
and or atoms to vibrate more rapidly. This produces more friction generating new phonons of
a higher energy producing a higher temperature.

Thank you for an interesting question.

Best regards, Your Mad Scientist
Adrian Popa