They will learn how to transmit sound in a vacuum, even if it seems impossible.

In cinema, there are no worthwhile conversations or articles about science in which the error sound explosions in space. Even some of the great landmarks of sci-fi cinema, such as star WarsThey make mistakes that we forgive for the overall quality of the saga. On the other hand, other modern titles such as interstellar, they take care of this detail very well, demonstrating an uncomfortable absolute silence in space scenes. This makes a lot of sense because sound cannot be transmitted in a vacuum. At least under normal conditions, this is impossible to do, as a group of Finnish scientists managed to do this with a rather interesting trick.

It should be noted that what these scientists have achieved cannot be applied to sound explosions in movies. Although, with a little more science fiction in them, it might be possible to achieve something interesting. But it is applicable in real life, in development smartphones or for temperature control, for example.

What these scientists have achieved is known as the acoustic tunnel, and it has been studied since 60sbut this has not been achieved so far, so this is no doubt a great advance in science.

Why can’t sound be transmitted in a vacuum?

Vacuum is defined as the complete absence of matter in a given space, something that can be created artificially or naturally. The latter applies, for example, to the case interstellar spacewhere there is some matter, but very little and widely spaced.

For its part, sound is transmitted by vibrations, the range of which from one particle of matter to another, like the hands of rock concert attendees carrying a singer from one end of the room to the other, and then back onto the stage. The same if they were far apart.

If there were no audience, the singer would fall to the floor and be unable to move around the room. WITH sound the same thing happens. If there are no particles through which vibrations can be transmitted, we will not hear anything. This is why it is said that sound cannot travel in a vacuum and why the sound explosions in some films ignore the scientific evidence.

How did they manage to fool physics?

These scientists, from University of Jyväskylämanaged to transmit sound in a vacuum thanks to two crystals from piezoelectric materials. So materials are known that can convert motion into electrical energy and vice versa. That is, if we make the crystal vibrate, we will get an electric current. And if we subject it to an electric field, we will cause it to deform.

We have already seen that sound is transmitted in the form of vibration. Therefore, if sound falls on a piezoelectric crystal, an electric field is produced when it vibrates. Then if it reaches a new crystal, the electric field will vibrate again. Thus, in a vacuum, sound had to propagate from one side to the other.

Of course, an important detail must be taken into account. And the fact is that in order for the electric field to reach the second crystal properly, both must be very close, at a distance less than a wavelength the sound to be transmitted. This shows that if only the spacecraft star Wars If they were made of these crystals and were very close, the cosmic explosions would not be heard. The problem with the crystals can be solved, but the distance is different, because the explosion can affect the second ship. All wrong.

But in real life it is really useful. reach journey of sound in a vacuum It may have many applications such as those mentioned above or quantum computing. In short, although it may not serve to explain sonic explosions in space, in real life it can perform some of the most interesting functions. Features that might also seem taken from the movie Science fiction.