Many people are fascinated with what goes on in space. It’s a world full of the unknown, sparking excitement and imagination. Now, thanks to advances in science and the latest technological innovations, our knowledge of space is growing, with new discoveries becoming more frequent.
One of the most amazing discoveries is the fact there are actually sounds in space. For many years, it’s been said there’s no sound in space. This is true in some respects, as there aren’t any sounds created in the conventional way, but far from space being silent, on the contrary, it has its own unique noises.
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How do we hear sound?
Conventional sounds, such as the ones we hear in our everyday life, need to travel through a medium so they can be heard. The sound wave is a “disturbance” that transports energy through a medium from one place to another, creating a sound that can be anything from a loud bang to a consistent low tone.
The “disturbance” in question is a vibrating object and the medium can be any number of interconnected particles such as gases, liquids and solids. An example of the creation of a sound is the ringing of a church bell.
The bell vibrates when it rings, which means it’s flexing in and out rapidly. When it flexes out, it pushes against air particles. Then, when it flexes in again, the air particles are pulled against adjacent air particles. Other particles are pulled in and out in sequence.
As a result of the pushing and pulling, a sound wave is produced. In other words, the bell’s vibrations are the original disturbance and air is the medium.
How does sound occur in space?
This is totally different from how sounds are created in space. There are very few particles, so any conventional sound waves would die away before they reached us.
Even big disturbances such as a supernova (the phenomenon that occurs when a star suffers a major explosion and ejects most of its mass) or solar flares (the eruption of high-energy radiation from the sun’s surface) are rendered silent before they are heard.
However, there’s another kind of sound created by a different process that doesn’t need to travel through any type of medium. This sound is created through gravitational waves and can therefore be heard in space.
How do we hear these space sounds?
Technologies such as the Laser Interferometer Gravitational Wave Observatory (LIGO) and the NASA spacecraft Voyager have enabled people to “hear” the universe for the first time in history.
LIGO is the largest gravitational wave observatory in the world and has two stations in the United States, one in Livingston in Louisiana and the second in Hanford, Washington.
Its purpose is to measure ripples that are occurring in the actual fabric of space – those distant gravitational waves that are arriving at the earth from a massive cataclysmic event taking place in the distant reaches of the universe.
The sounds resulting from the natural event would have gone undetected on the earth, prior to the discovery by LIGO, which first became operational in 2002, following a massive construction project that had begun eight years earlier in 1994.
Kip Thorne, Rainer Weiss and Barry Barish, the American physicists behind LIGO, were awarded the Nobel Prize in Physics in 2017 for their contribution to the research and subsequent observation of gravitational waves.
What were NASA’s space sounds?
Prior to LIGO’s detection of sounds from space arriving at earth, the only conclusive proof of the existence of such sounds came from footage recorded by the NASA Voyager programme, which recorded actual sounds from space.
The subsequent footage was posted on YouTube in November 2016. It became a hit, thanks to sounds that were described as “relaxing” and ideal for meditating by some people – while others found them “chilling” and eerie!
NASA designed and created special instruments to record the electromagnetic vibrations and make them into sounds that human ears could hear.
What causes the space sounds?
Up until December 2018, LIGO had detected gravitational waves from space 11 times. Ten of these were the sounds made by the mergers of binary black holes. A black hole is a phenomenon that occurs in space. It exhibits extremely strong gravitational effects, meaning that nothing can escape from inside it.
Binary black holes are two black holes that orbit closely around each other. When they merge, an immense amount of energy is given off as gravitational waves. LIGO has detected the waves given off by ten black hole mergers.
The eleventh detection by LIGO picked up the gravitational waves that resulted from the collision of two neutron stars, on 17th August 2017. This was the first time in history that such a detection had occurred. The stars spiralled closer and closer together until they finally merged.
The resulting disturbance was so massive that it was not only detected by LIGO, it was also seen on seven continents by 70 different observatories. Optical signals were so massive that they could be picked up by conventional telescopes.
Data being continually detected by LIGO may have far-reaching effects on various aspects of physics, such as nuclear physics, gravitation, astrophysics and particle physics.
Noise control solutions
While the phenomena of detecting sounds from space is fascinating, for people living their day-to-day lives near noisy industrial premises, a building site or next to noisy neighbours, the sound of silence would be preferable!
Sound Planning provides a wide variety of services and products aimed at minimising noise nuisance. As experienced acoustic consultants, we specialise in the design and supply of noise control products.
Please contact us for information on our bespoke solutions.