Everyone will hear you scream in space: physicists have learnt to transmit sound in a vacuum, but there's a problem
The famous slogan from the sci-fi horror film Alien may have to be modified somewhat, as the statement that "no one can hear you scream in space" has suddenly become outdated. Physicists have managed to invent a method that allows waves to be transmitted in the space vacuum.
This is stated in a study published in the journal Communications Physics. However, like most breakthrough ideas, this has certain limitations.
As you know, sound on Earth is transmitted by vibrations moving through the air. Moreover, the density of the air can change the way we hear sound: your voice on Mars, Venus, or Earth will sound completely different.
In space, however, sound simply cannot "travel" through space, as there is no air, and therefore nothing to vibrate against. Therefore, neither screams nor explosions make any sense in a vacuum and are accompanied by complete silence.
But this is likely to change in the near future. A pair of Finnish physicists from the University of Jyväskylä's Centre for Nanoscience, Juoran Geng and Hilari Maasilta, have managed to make sound waves transmit through an airless void. The only problem is that their method works only at fairly short distances.
In scientific terms, the method relies on the use of piezoelectric materials to convert sound waves into an electric field that can cross a vacuum and then be converted back into sound waves on the other side.
According to physicists, piezoelectric materials include crystals (e.g. tourmaline and quartz), some types of ceramics and polymers, and some semiconductors such as zinc oxide.
What makes these materials special is that they produce an electrical voltage when they are pressed, bent, stretched or subjected to vibrations.
So to communicate in space, a person will need to stand in front of a piezoelectric plate and speak to it. The sound will make the air vibrate, and these vibrations will pass through the plate, creating an electric field. This field will pass through the vacuum, pushing and pulling charged particles - such as those in the second piezoelectric plate on the other side of the vacuum. In this way, your scream will travel from one plate to the other in the form of an electric field, but when it encounters the other plate, it will be transformed back into a sound wave.
The researchers admit that in most cases, the effect of sound transmission in this way was not very large, but they found cases where "the full energy of the wave jumps through the vacuum with 100% efficiency".
The main problem with the idea is that the gap between the two piezoelectric materials must be smaller than the length of the sound waves being transmitted.
If you take an average person, their scream can travel from 1 to 12 metres. The deepest sounds a person can hear have wavelengths of about 18 metres.
As Inverse notes, Geng and Maasilta say their method could be useful in tiny systems that combine electrical and mechanical parts, such as some types of sensors or even for temperature control. Other teams of engineers have been experimenting with ways to use sound waves to move heat for several years.
Earlier, OBOZREVATEL reported that a "perfect" explosion occurred in space, which makes no sense and contradicts the laws of physics.