Complex Numbers

In a Vacuum

One thing that often bugs me about science fiction movies and shows is when they get the "science" part wrong.

    How long could you survive in space without a spacesuit?  
The vacuum of space is unforgiving, and time is not on your side.

It usually doesn't stop me from enjoying the story, unless it's egregious, but how long would it take to make sure you get something right?

Today's topic, though, is one that we don't have much empirical data on. It's not like we can shove people out of airlocks and time how long it takes until they die. Well... not ethically.

And yet, some recent shows don't seem too far off the science on this one.

Many of us have dreamed of going into space.

Preferably inside of something.

But traveling in space brings a whole set of challenges and hostile environments, so it's vital to recreate the conditions on Earth that have allowed life to evolve and flourish.

As I've mentioned before, we can only live in a zone of atmosphere proportionally thinner than an eggshell. Everywhere else in the universe, as far as we know, will kill us in varying amounts of time, from instantly to slightly longer than instantly. Hell, even our evolved environment kills us, but usually over a matter of years, not seconds.

Spacesuits allow astronauts to venture outside their spacecraft for short periods, by providing the air, water, pressure and physical protection needed for a human to survive.

Sucks if you're one of the people who also need companionship to survive. I guess there's the two-way radio for that.

Sci-fi movies and shows, including "2001: A Space Odyssey" and "The Expanse," have portrayed astronauts suffering — and surviving — short exposures to outer space without a spacesuit, while others have depicted a range of grisly deaths.

I thought The Expanse was great, but it didn't always get the science right, either.

"Within a very short time, a matter of 10 to 15 seconds, you will become unconscious because of a lack of oxygen," according to Stefaan de Mey, a senior strategy officer at the European Space Agency (ESA) charged with coordinating the strategy area for human and robotic exploration.

I still don't think that's the worst part.

Bodily fluids, such as saliva and tears, would begin to boil. A human body would also expand, but the skin would be elastic enough to cope with the pressure change, de Mey said, adding that horrific movie portrayals of exploding humans are not accurate.

And it's even worse than that. Fluids don't start to boil because they get hot. They boil because the pressure drops. You know how water boils at a lower temperature in Denver than it does in New York? Well, space is even more empty than Denver air, and the boiling point drops even further.

Depending on where you are, you can boil and freeze at the same time.

Because you'd be unable to alter your dire situation, brain death would follow within minutes, unless you were rescued and brought back to the safety of the pressurized, oxygen-rich environment of a spacecraft and resuscitated.

"Within minutes?" Weasel! Of course, as I said, we have no empirical evidence of this, so uncertainty is understandable. So I'm going to go with the time it took to rescue Star-Lord in Guardians 3.

Spacesuits also protect from various types of radiation. In LEO, there is protection from some forms of radiation. Prolonged or long-term exposure to electromagnetic radiation from the sun would cause health issues, including radiation sickness and an increased risk of cancer. UV light would also burn the skin.

Sure. I just got yeeted out an airlock, and my first (and last) thought is, "Boy, it sucks to be exposed to this much radiation."

Being in space without an EVA suit becomes very deadly — very, very quickly. While someone could survive this grim scenario, they would want to have very little air in their lungs and get back to the safety of a pressurized spacecraft within seconds — or hope to be rescued and resuscitated within minutes.

I think the important takeaway here is that death by airlock isn't instantaneous, not like if you're standing next to the fusion reactor when it explodes. No, you'd have time to think about it, much like those seconds between when you jump off the building and hit the pavement.

In the latter case, though, the last thing that goes through your mind would be concrete.