New Sounds from Space
Objective: This file expands the basic notion of sound by considering gravitation waves emanating from space. Are these strange and unusual sounds musical? Of course, it is up the individual and one's own brain.
Think for a moment about all the sounds you encounter during your daily activities. Some of these we classify as noise (a jackhammer). Others give us information about the environment, sometimes warning us of danger (an ambulance siren). Some sounds we simply ignore and subconsciously accept (e.g., incidental music in a mall or grocery store. Still other sounds, like birds singing, are pleasing enough possibly to be considered music.
How do new sounds, especially pleasing or intriguing enough to be considered possibly as musical, enter our environment? Technology is one source. New inventions and machines (the whirring of a computer hard drive) produce new sounds never heard before.
In 2016 scientists were able to detect gravitational waves coming from outer space and translate these into sound using basic loud speakers. Recall that sound is composed of waves that travel through the environment by exerting pressure against air molecules. Recent discoveries in physics point to the possibility that gravitation waves exist in outer space as wave forms even though there are no air molecules in space. So why not convert these to sound?
Physicists liken gravitation waves as ripples in the fabric of space-time. As planets revolve around the sun gravitational forces are at work, which set off ripples or gravitational waves through space. Some of these vibrate within the human range of hearing (20-20,000 hz). They cannot be heard in space since there are not air molecules present. However, scientists detected these waves in February, 2016, using Laser Interferometer Gravitational-Wave Detectors. They converted the data into sound waves that we can hear through earth-bound conventional means--loud speakers.
The following link takes you to a short site where you can hear the sound of two black holes colliding. Note in this article why Einstein would have been especially pleased by the discovery of this sound and be sure to play the short video as well.
http://www.popsci.com/listen-to-sound-gravitational-waves Links to an external site.
Do these gravitational waves actually produce sound? We know they produce waves that travel through space. Note that the plasma wave instruments used to detect the gravitational waves do not detect sound. In other words, it seems that these waves do not make a sound that humans can hear as they travel through space. However, the plasma wave instruments do indicate frequencies and pitches of the gravitation waves. When these are played through loudspeakers sound is produced, which humans can hear. Go to the following link to listen to more of these "space" sounds.