In Space...Can Anyone Hear You Scream?

"In space, no one can hear you scream"1979 sci-fi movie 'Alien' gave us this quote, that defined the whole genre. If there is one fact that all of us know about space, is that sound can not travel in a vacuum.

Is there really no way to hear someone's scream in space? well, there is a'trick' [apart from Radio coms]. Let's consider ascenario.

Say our hero is doing a spacewalk, just outside of his craft. Radio is down.The pilot of his shuttle is screaming for help.He can hear the scream faintly. How? Simple! His helmet was touching the shuttle's hull.

Her vocal cords vibrated the air molecules in the shuttle. Some of the vibrational energy transferred into the hull and from the hull to his spacesuit--> the air in the suit --> eardrums. In the same way, two spacewalkers can talk, by touching each other's helmet ( as shown in tv series 'The Expanse'Season 3 episode 13).

Let's extend this discussion to screaming on the surface of a planet. Now, the properties of sound depend on the medium.

The atmosphere of Mars is really really cold and thin (i.e. less dense) compared to Earth. So, the speed of sound there is about 30% less than On Earth. So, the frequency of your scream will be much lower on mars...i.e. you will have a smooth Bass-y voice. Funnily, as Mars atmosphere is rich with carbon-di-oxide, it absorbs sound waves really fast. So your loudest scream would be barely audible from a few meters away.

Another really intriguing place in the solar system is Saturn's moon, Titan( https://en.wikipedia.org/wiki/Titan_(moon)#Atmosphere ).Titan's atmosphere is really cold (-179.2 degrees centigrade)and a thick atmosphere (19 times more massive than of Earth). So, the speed of sound is much slower than in earth, resulting in the frequency of your scream to go down..increasing the bass. Though Titan's atmosphere is mostly nitrogen so..sound travels pretty good and far.

At last, how can we forget our Evil twin, The Venus?Venus is super-duper hot ( u can bake a pizza just by setting it in sun), and its atmosphere is really really dense..(90% carbon dioxide). Because of high-temperature sound in venus travels much faster than on earth. So, you should sound slightly shriller over there, right??Wrong...According to researcher Timothy Layton, due to a much higher density of Venus's atmosphere, human vocal cords will work a little differently. As a result, you will get a deeper voice in venus than in other planets discussed.

So, we can safely assume that unless you are in the space without any space suit and screaming to the naked voice alone, there are always some ways people can listen to you.

Anyway, that is all for today. Any suggestions and corrections are welcome. See ya on the next blog. Until then keep your Eyes open & Minds open.