5 Everyday Things That Go Totally Nuts in Zero Gravity
Humanity has a strange tendency to think of physics in terms of how it operates on Earth, despite the fact that our little ball of mud amounts to little more than a speck of roach poop in the grand scheme of things. If you really want to see how physics works, you need to go zero gravity, man.
Zero-G environments are totally a part of our physical universe, and an overwhelmingly dominating part at that. This means ye olde laws of physics are totally at work in there, too. They just like to operate like a goddamn maniac.
Fire Turns into Floating Spheres of Glowing Energy
Before reading further, take a moment to go light something in your house on fire. That flame looks like that due to gravity, specifically the fact that hot air rises. The flame is fueled by oxygen, letting the excrement of carbon dioxide and water vapor heat up and lower in density. Eventually, they float away, only to be replaced with fresh, cool oxygen to be murder-burned. However, take that shit to zero gravity, and things will get weird. Fireball weird.
Yep, that there is a space flame. In zero gravity, puny Earth things like buoyancy and convection don't exist. So when you light a match, the carbon dioxide goes nowhere. It just gathers around the flame like hobos around a barrel fire. Meanwhile, the flame keeps happily engorging itself with oxygen until the hobo CO2 all around it snuffs it out.
Left: Normal flame. Right: Awesome ball of space fire.
That flame shape you're used to can only happen because the fire forces hot air to rise upward. Since none of that really happens in zero gravity, the flame just expands in all directions in a desperate search for random oxygen particles. Essentially, this means fires in zero gravity are lower in temperature, consume less oxygen, are dimmer in terms of brightness ... and totally float around like fireballs if you, say, ignite a floating drop of gasoline.
How astronauts resist the temptation to start mage duels the second their spacecraft leaves the atmosphere, we'll never know.
By the way, you get the exact same effect if you boil water.
Since your house is engulfed in flame by now, you'll notice that any standing liquids have probably begun to boil. Your average water boiling session on Earth produces lots of tiny bubbles that float up to the top, but in space, that pesky lack of buoyancy and convection strikes again. The bubbles just sort of sit in the middle of the scalding hot liquid, refusing to move until they eventually form one giant, floating Voltron bubble:
Don't you just want to stick your hand in there? We guess it's the ability to resist such temptations that qualifies people to be astronauts.
Liquid Surface Tension Becomes Hardcore
Here's a fun experiment for your next 30-minute shower crying session: Clench your fist, dunk it in the water, and try to capture a film of water in the circle formed by your thumb and index finger. Chances are that whatever tiny amount of water you can capture almost immediately bursts away as surface tension loses the fight with gravity. Awesome, yes?
No. Of course it isn't. But once you remove gravity from the equation, shit gets real.
We think he's saying something about being a "space god."
In zero gravity, surface tension holds strong, and that same small puddle of water would be a sticky pool with the apparent consistency of jelly.
There's no way he's not making a "bloop bloop" noise when he does that.
This is because gravity on Earth causes the liquid to fall into the multiple nooks and crannies of your misshapen mitt, until the fickle film of water bursts. In zero gravity, surface tension has no forces keeping it down; the water just maintains its cohesiveness and doesn't budge unless you specifically shake it off. That is, if you can; these zero-gravity water films are like little sheets of clingy rubber, and even vigorous shaking may not be enough to remove them.
And if you want to get really freaky, you can just use colored liquids:
Now all we need is a black light and some club music.
Tell us that doesn't look like a little color themed X-Man two seconds away from seriously ruining someone's day.
Sound Gets Physical
When gravity goes missing, other forces step up to the plate, allowing scientists to study them in ways they never thought possible. Sound is no exception.
Um ... Don, what do you have there? You're frightening us.
The man above is veteran NASA astronaut and ISS chemical engineer Donald Pettit handily engineering a vacuum cleaner into a didgeridoo in order to demonstrate sound waves hitting spheres of water. The man below is veteran NASA astronaut and ISS chemical engineer Donald Pettit getting carried away.
Um ... DON?!
Now deeply entrenched in native mode, Pettit uses his electric didgeridoo thing to blast some spheres of water into ... WHAT THE SHIT IS HAPPENING?
"It's attacking! Run!"
Man, that water is pissed. The overpowering oscillations of sound easily break that nasty, rubbery surface tension of the weightless liquid, making tiny droplets spout off in all directions. And that's just the tip of the iceberg. Varying frequencies of sound waves in zero gravity can (and totally will) create anything from subtle rippling to total insanity.
Here, let's witness the birth of the dubstep golem, brought to you by some corn starch and hard, hard bass:
And the devil.
Static Electricity Pretends to Be Gravity
Static electricity is already pretty weird. What child wasn't mesmerized to find he could make the dog's hair stand up when he rubbed it with a balloon, or that he could have electric shock fights with his brother in that motel with a really shitty rug? Well, once again, take an already weird phenomenon into space and it only gets weirder:
Those are water droplets orbiting a knitting needle. Statically charged objects work their magic by exerting attraction to their opposites, and in space, the lack of gravity actually makes this static attraction closely resemble the physics of gravity. So take a moist piece of paper and rub it over a knitting needle to generate a static charge, then squirt small droplets of (also statically charged) water at the needle, and that's what you get. The charges of the needle and droplets find they have no gravity to mess their relationship up, so they start to replicate gravitation physics themselves.
The guy performing this experiment, by the way, is none other than Don Pettit, who has become famous for making accidental discoveries by fooling around in space. And when we say "fooling around," we of course mean "he solved one of the biggest mysteries in the history of astronomy." During one particularly uneventful space day, he poured some salt into a plastic bag and shook it around in front of a live video feed for no real reason but shits and giggles. Several seconds later, the salt globules started holding hands and singing "Kumbaya":
A 12-pack later, they were all naked.
Back on Earth, another scientist happened to be watching the live stream and realized that Pettit had just accidentally solved a critical stage of planetary accretion, as in the force that makes planet stuff stick into enough other stuff to become planet-sized. Scientists around the world soon realized that in a zero-gravity environment, tiny particles bumped into each other and created static charges, causing these infinitesimally small particles to cling to each other, replicating gravitational physics and solving the mystery behind how planets are formed.
Although we can't help but think that at least part of the attention is because the process just looks cool as all fuck.
No way he's not high as hell, doing all this random stuff up there.
Every Living Thing Becomes a Weird Mutant
Here's something else you never really think about: Pretty much every living thing you've ever seen looks like it does because it evolved in Earth's gravity. Take the gravity away, and pretty much all of them go apeshit. Fish swim in tiny circles for no apparent reason, cats and pigeons stumble around helplessly, and even microscopic organisms like cells lose their shit. But then there is moss, which does this:
It's a galaxy made out of fur!
Moss, like almost all plants, is gravitropic, meaning that it grows in the opposite direction of gravity's pull. On Earth, this means moss usually grows in a disorganized tidal wave of moist shit, aiming toward light and away from Earth's gravitational pull. But when it's grown in zero gravity, it pulls out all the stops and starts growing in a weird, clockwise spiral.
If it could speak, it would be all like, "Fluff? Fluff, fluff, fluff ..."
It's not a "Meh, all plants can do that" thing, either; moss is the only plant ever grown in zero gravity that exhibits consistent signs of pattern growth. All other vegetation loses all orientation and starts growing in random directions. Scientists discovered the phenomenon back in 2002 and still have no real clue why moss sees fit to grow as a spiral instead of an unruly clump of crap.
But moss isn't the only living thing that seems to really come out of its shell in zero-G. Food poisoning bacteria, mainly salmonella, love zero gravity. When scientists gave salmonella a ride on a space shuttle to study how zero gravity resonated on it, the result was a terrifying re-enactment of John Carpenter's The Thing. The salmonella that went into space was ordinary -- what came back to Earth was three times more deadly.
It's what we here at Cracked refer to as the "Ew, gross, poop" experiment.
Not only do pathogens like salmonella become deadlier, but bacteria and microbes grow a whole lot quicker. The picture above highlights the difference between a control group of bacteria (left) versus a space-grown bacterial colony (right) with 75 percent more diarrhea. Because diarrhea is the exact thing you want to flourish on a goddamn space station.
"I'm going to need a raise. And a flame thrower."
Another species that fares extremely well in space is, unsurprisingly, the common cockroach. Space-bred cockroaches aboard a Russian spacecraft have been known to develop quicker, be more resilient, and have far more stamina and speed than Earth roaches, although this may have more to do with the Russian space program than with zero gravity.
All right, so what about people? Do we gain any superpowers when freed from the oppressive crush of Earth's invisible fist?
Nope! We just start to look weird. Many of the human body's mechanisms rely on the presence of gravity, and without it, all sorts of fluids start roaming about inside our body, gathering in hollow and strange places, such as the goddamn face. The result is something called the "Charlie Brown phase," where an astronaut's head inflates with fluids and causes him to look like a bloated bobble head. Here's a before and after:
We're positive that mission control sounds like the teacher.
Fernando would love it if you would find it in your heart to donate to The Debate League, his friend's non-profit organization.
Related Reading: Before you get TOO excited about our astronomic future, click this link and learn why space travel might suck. Don't let Cracked get you down on the whole concept of extraplanetary exploration. You can get up to some pretty badass stuff in space, including making friends with a Robonaut. And if you thought the Mars Rover was as awesome as modern space missions got, you'd best think again. Because the fictional HAL 9000 has a REAL robo-centaur buddy.