Sunday Space | Is there any sound in space?

Critics will point out inaccuracies in science fiction films when there are sounds of explosions or lasers blast. It is true, to a certain point, but there are sounds in space.

The way we think of sound is the ability for the human ear to pick up audio signals. To do so, it needs to be in a frequency we can hear. It also needs to move through a medium, such as air, and as the long waves travel, it compresses the particles in the medium, eventually causing them to vibrate for our ear to pick them up.

However, our ear can only hear a certain frequency range of waves. Frequency is the measure of how long or short the waves are.

It is measured by how many waves pass through a fixed point in a certain time. A longer wave will have a lower frequency, less waves make it through in time. A shorter wave will have more, and therefore a higher frequency.

Our ears can only pick up a certain frequency range, about 20 hertz (Hz) to 20kHz (20,000Hz).

Of course, there are lots of higher frequencies we can't hear travelling through the air, like radio stations that broadcast in 100s of megahertzs (millions of hertz).

However, in space, it is not a perfect vacuum. There are places in the universe that do have mediums. A great example is the sun.

The sun has the solar wind, blowing off of into space. Occasionally we get eruptions from the sun like coronal mass ejections travelling through space. These have their own medium of charged gas, called plasma, travelling with them. In this plasma are vibrations, compressing the charged particles, just like sound waves in air.

It is in a very low frequency, well below what our ears can hear. But satellites can pick them up. The waves have different intensities, and pitches, all of which satellites that monitor the sun, and as these waves hit the Earth, can detect.

Scientists and musicians, like Kim Cunio at the ANU School of Music, have teamed up together, and can change the scale of the frequencies picked up by these satellites into a range our ears can hear. It is not much different to radios picking up frequencies we cannot hear, and converting them for us.

We can find a way to actually hear sounds from space.

There are also waves that do not need anything more than the medium of space-time itself.

Gravitational waves are ripples of gravity that travel through the fabric of the universe, compressing it as it travels just like sound waves compress air particles.

READ MORE SUNDAY SPACE COLUMNS:

These waves are tiny, and huge detectors with lasers shooting kilometres down to a mirror. As the waves hit the Earth, it shifts the light bouncing off the mirror a tiny fraction that the detectors can pick up.

Just with the sun sounds, you can change the frequency of these waves into a sound we can hear.

In space, we may not be able to hear you scream, but we can find ways to hear other things.