Seeing the headline, you must be thinking – but I never hear anything! Unfortunately the pitch is nearly a trillion hertz, so it’s not really something we can hear and enjoy. but.. nevertheless, it’s true. Stars are able to make sounds, but they are millions of light years away. So you can’t really hear them to determine whether they are singing or just talking to themselves.
Little stars can sing to themselves
In a recent study, NASA has discovered a group of massive red stars that are actually humming to themselves. The planet-hunting Kepler space telescope recently spotted sound waves emanating from the stars, the Wall Street Journal reports. NASA recorded the tune, and played it recently at a press conference in Denmark. “It is a giant red concert,” says the astronomer who made the recording. “They have many different frequencies and overtones.”
The sound waves can help astronomers determine the size, density, age, and structure of the stars, in much the same way seismic waves reveal details about Earth’s interior. “To measure the size of the star, we essentially measure the tone of these musical notes,” says one astronomer. “The sound waves travel down into the star and bring information back up to the surface of the star that Kepler can see as flickering.”
The study of fluids in motion – now known as hydrodynamics – goes back to the Egyptians, so it is not often that new discoveries are made. However when examining the interaction of an ultra-intense laser with a plasma target, the team observed something unexpected.
Scientists … realized that in the trillionth of a second after the laser strikes, plasma flowed rapidly from areas of high density to more stagnant regions of low density, in such a way that it created something like a traffic jam. Plasma piled up at the interface between the high and low density regions, generating a series of pressure pulses: a sound wave.
Final Few Words on the topic
However, the sound generated was at such a high frequency that it would have left even bats and dolphins struggling! With a frequency of nearly a trillion hertz, the sound generated was not only unexpected, but was also at close to the highest frequency possible in such a material – six million times higher than that which can be heard by any mammal!