How "sounds" space
Photo by Paul Hudson CC-BY
Sound is a physical phenomenon that represents elastic waves propagating in a particular medium. In a narrow sense, sound refers to vibrations perceived by the hearing organs of animals and humans. The eardrum in our ear picks up high-frequency changes in air pressure, and the brain processes the received signal.
In space, we hear nothing, because there is no medium suitable for sound propagation. However, we will find out if a supernova explosion occurs near our planet - the “explosion” will be the result of the deformation of the Earth’s atmosphere under the action of light.
However, if we are talking about electromagnetic oscillations that a person is not capable of perceiving, then their conversion into a sound format can give interesting and valuable results. For example, in this video, NASA processed the received signals from different planets:
At Geektimes, they already talked about a NASA account in SoundCloud, which opened the door to the world of “cosmic” sounds (for example, a digitized recording of sounds from the Voyager gold record was published ) and brought the synthesized recording sound from Venus as an example of what can be recorded on the surface of a planet.
But back to the "sounding planets." Radio waves emitted by celestial bodies, can be considered using a special device - an interferometer .
Interferometers are widely used in astronomy to create radio and optical telescopes with high resolution. An example is the giant ALMA radio telescope, consisting of more than 66 antennas distributed over a large area, which receive radio waves emitted by astronomical objects.
The principle of operation of an astronomical interferometer is as follows: suppose that two antennas are directed toward the space body X. Since the radio waves move in space at a constant speed, the radio waves from object X will reach the antennas set at a certain distance from each other at different points in time. After that, the signals of the two antennas can be interfered and the desired source information can be extracted from the resulting signal.
Optical telescopes, like our eyes, are imperfect and allow us to make observations only in the visible range of radiation. ALMA was specifically designed to record long waves. Thanks to this, scientists were able to look into the farthest corners of the universe, hidden from our eyes by clouds of gas and cosmic dust.
The International Space Station is another project whose goal is to expand our knowledge of space. And here's an interesting question, but how does the ISS sound? Experts involved in the training of astronauts to fly to the station, they say that everything there sounds exactly the same as on Earth.
The International Space Station itself consists of modules, and its internal space resembles narrow cylindrical corridors. There are 14 modules in total, each of which contains research laboratories, utility rooms, warehouses, sleeping places, and simulators.
In this regard, the ISS is quite a noisy place: the fans tirelessly drive air through the entire station. All this is reminiscent of several dozen computers “overloaded with processes”, whose coolers rotate at a breakneck speed and create a rather strong hum.
In addition to the fans on the ISS, there is still a large number of pumps, compressors and other devices that emit sounds, for example, a special ARED space simulator, in which a cunning system of cylinders, levers and disks provides loads of up to 600 kg. Astronauts need to train, and to raise an ordinary bar in space is inconvenient and useless.
The noise level on the ISS varies from 58 to 72 decibels (maximum 80). Of course, all parts of the station sound differently: the noise level on the ISS can be assessed by video(pay attention to how the sound changes at 24 minutes when switching to the Russian space module).
If you don’t like the video tour of the station, then astronaut Chris Hadfield especially for you has uploaded several audio tracks recorded in various parts of the ISS to SoundCloud. Moreover, he even recorded the song, accompanying himself on the guitar.
Many musical compositions can very accurately convey the feeling of space and immerse us in a cosmic mood in a matter of seconds. Someone thinks that the greatest number of space associations are associated with the songs of David Bowie ( 1 and 2 ). Listening to them, you seem to go on a long journey.
Others advise to pay attention to the classicthe works of Gustav Holst "Planet". There are even more interesting options . Or the application "Inception", which told Wired:
PS More materials on the topic of audio - in our blog " Hi-Fi World ".