Star Sound behaviour can occur only at very early stages, when the system is dominated by its initial state as per the TIFR Experimental Study.
Physical Review Letters published the results of this in the recent days.
TIFR scientists were to produce very hot, solid density plasma that sounds just like a star. Femtosecond laser of very high intensity was used to produce the star-like object.
Research Scholar, Amitava Adak from Ultrashort Pulse High Intensity Laser Lab, TIFR said, “We were able to produce the star-like object for hundreds of picoseconds (10) to nanoseconds (10) using the laser”.
By the simple technique, pump-probe, the sound will be inferred. This is the main laser that produces the star-like object. And the probe is a tiny part of the laser which helps in studying evolution of the object clearly.
Mr. Adak said, “We measured the intensity and spectrum of the reflected probe and we could find very high frequency sound being generated in the hot, dense object. It was a chance discovery.”
The frequency of the sound that is produced is way beyond 20,000 Hertz. It is beyond the outer limit of human hearing. We can’t hear for this sake.
Due to the Hydrodynamic flows of different velocities, the sounds with greater intensity will be produced. The flows that are discussed above will reduce a density gradient in the plasma.
The plasma that is flowing will be moving from a region of high density to low.
Rapidly moving plasma encounters a stagnant flow in the plasma corona and results in the Hydrodynamic instability.
Due to this, a localised build-up of pressure will be formed. And this make a move further upstream.
“Plasma piled up at the interface between the high and low density regions generates a series of pressure pulses: a sound wave,” a release said.
“This behaviour can occur only at very early stages, when the system is dominated by its initial state. The picosecond-scale observations helped the team to detect the high frequency oscillations,” Mr. Adak said.
Dr. John Pasley from York Plasma Institute in the Department of Physics said, “One of the few locations in nature where we believe this effect would occur is at the surface of stars. When they are accumulating new material, stars could generate sound in a very similar manner to that which we observed in the laboratory — so the stars might be singing — but, since sound cannot propagate through the vacuum of space, none can hear them”.