Can Sound Really Exist in the Vacuum of Space?

[deepthishan]

I have read that sounds exist in space. Some examples include:

1. http://www.ted.com/talks/honor_harger_a_history_of_the_universe_in_sound.html
2. http://www.nasa.gov/centers/goddard/universe/black_hole_sound.html

How does sound propagate in space if "Outer space has very low density and pressure, and is the closest physical approximation of a perfect vacuum" ? (- Wikipedia)

Thanks!

 

[Drakkith]

I have read that sounds exist in space. Some examples include:

1. http://www.ted.com/talks/honor_harger_a_history_of_the_universe_in_sound.html
2. http://www.nasa.gov/centers/goddard/universe/black_hole_sound.html

How does sound propagate in space if "Outer space has very low density and pressure, and is the closest physical approximation of a perfect vacuum" ? (- Wikipedia)

Thanks!

Number 1 is simply radio signals that we receive and turn into sound waves ourselves. It is very much like listening to the radio.

Number 2 is the result of the scientists measuring waves through the gas in the cluster and changing them into a sound. Because of the low density, the frequency of these waves is very very long, as the article said it was 10 million years long. (1 hertz is one cycle per second, this one would be 1 cycle per 10 million years.)

 

[deepthishan]

Number 1 is simply radio signals that we receive and turn into sound waves ourselves. It is very much like listening to the radio.

Number 2 is the result of the scientists measuring waves through the gas in the cluster and changing them into a sound. Because of the low density, the frequency of these waves is very very long, as the article said it was 10 million years long. (1 hertz is one cycle per second, this one would be 1 cycle per 10 million years.)

Thank you- your answer cleared up a number of questions!

However, how can these transverse waves be converted to longitudinal sound vibrations? (As guessed I'm not a Physics Major!)

 

[Drakkith]

By figuring out the frequency. If you were to look at me wave a string back and forth you could count the number of times it goes up and down per second and come up with the frequency. In this case they were able to figure out that it was once per 10 million years.