Totally dumb Wall-E question. (SPOILERS)

July 9, 2008 6:08 AM

Totally dumb Wall-E question. (SPOILERS)

So dumb, sorry, but it's bugging me.

So there's that part where Eve chases Wall-E and the plant out into space because AUTO tried to get rid of them. When Wall-E and Eve reunite in deep space he pulls out the plant to show her the mission isn't lost. I was like, OMG HE'S GONNA KILL IT, NOW THEY'LL NEVER SAVE EARTH. But the plant, of course, lived and the show went on.

What would happen to a plant exposed to the forces of deep space? Would a plant die instantly in space or would it take a couple minutes for it to die? Would it pull a Total Recall or would it just sort of wilt? Or would it remain perfectly preserved, but dead?

posted by The Straightener to grab bag (14 comments total)

The water in the plant would freeze pretty quickly, expanding the water and rupturing the cell walls, causing it to wilt and die. But hey, it's a cartoon.
posted by kuujjuarapik at 6:11 AM on July 9, 2008

NASA has a page on the effects of exposure to space on humans. The page suggests that being in space for half a minute or less would not cause permanent injury to humans. Also, it specifically points out that a person would not freeze. As I recall, the plant is in space for less than that, so I suspect it's actually fairly realistic, so long as Wall-E or Eve kept it warm and out of vacuum otherwise.

Now, if you want artistic license, consider how long that little fire extinguisher lasted...
posted by jedicus at 6:30 AM on July 9, 2008 [1 favorite]

The plant was exposed to space for longer than 30 seconds. WALL-E shows EVE the plant immediately after surviving the pod implosion, but then they "dance" for at least a minute or two. Sure, he put the plant back into his body compartment, but unless he has a life support system in there that would re-pressurize after being opened in space the conditions wouldn't be any more favorable.

However, I'm not sure how long it would take for the plant to actually wilt and turn brown. Perhaps the Holo-Detector didn't require a living plant, just one that looked alive.

Great movie, by the way!

--FCOD
posted by flyingcowofdoom at 6:37 AM on July 9, 2008

Whoa, that NASA link lays down some ice cold truth! Thanks!
posted by The Straightener at 6:40 AM on July 9, 2008

Well, humans and plants are different organisms. Humans are endothermic and can create body heat, most plants cannot. Also, the surface area of a plant compared to it's volume is greater in a plant than a human, more surface area exposed = more rapid cooling, less volume = less thermal mass to stay warm.
posted by kuujjuarapik at 6:41 AM on July 9, 2008

The way I rationalized it to myself was that it was way in the future and that plant is some sort of SuperPlant!! because it was able to grow in a fridge amongst garbage.
posted by spec80 at 6:45 AM on July 9, 2008 [1 favorite]

The plant has been evolving in an inhospitable toxic wasteland for 700 years and can now weather the effects of space with no problem. For instance, it was found sealed in a refrigerator cut off from the Sun.

Morpheus voice: "You think that's chlorophyll you're photosynthesizing? . . . Hmmph!"
posted by cowbellemoo at 6:47 AM on July 9, 2008 [2 favorites]

To counter what kuujuarapik says, on the other hand plants can tolerate a wider range of temperatures, and starting at a lower temperature means they lose heat less quickly. Their internal circulation is slower, meaning heat will be conducted through them more slowly too. It's not at all obvious that small plants will cool to the point of death more rapidly than a person.
posted by edd at 6:50 AM on July 9, 2008

In Space, the plant wouldn't cool off and freeze . For it to freeze means that energy (in the form of heat) would have to go somewhere. Space isn't really cold, it's just "not"; that is, there's nothing in a vacuum to which the energy can be transfered. In an atmosphere, things can cool down because the air can take some of the energy away. Since a vacuum is the absense of things, the temperature will stay relatively the same as there's no where for the energy to go. That's why the most energy efficiant windows have a layer of vacuume between two planes of glass, to stop the transfer of energy.

If anything, the loss of presure while maintaining temperature would cause the water to boil. Drop the pressure enough (like in a vacuum) and the water'll be a gas no matter what the temperature. In humans this doesn't happen because the circulatory system and skin are able to maintain some sort of pressure system on the body's liquids. It's hard for me to say what'd happen to a plant. The cellulose in it would probably prevent it from losing structure, but I'm not sure if it would maintain a pressurized system or not. Plants tend to be rather porous, so I'd expect the water might boil within the plant, but could very well stay put, effectively turning back into a liquid when brough back into an atmosphere.
posted by swashedbuckles at 7:07 AM on July 9, 2008 [1 favorite]

In Space, the plant wouldn't cool off and freeze .

Yes, it would. Probably not in the time the plant in the movie (I haven't seen the movie) is exposed, but given enough time, it would. (Or to be precise, it would reach the freezing temperature of water, but whether there would be any water left to freeze or not, I couldn't say.)

For it to freeze means that energy (in the form of heat) would have to go somewhere. Space isn't really cold, it's just "not"; that is, there's nothing in a vacuum to which the energy can be transfered.

It would have to go somewhere, but it doesn't have to go to something. While conduction (if it's not touching anything else) or convection are not possible methods of heat loss in space, radiation still applies. There doesn't have to be anything in a vacuum to receive the energy for something to cool via thermal radiation.
posted by DevilsAdvocate at 7:23 AM on July 9, 2008

Cooling down by thermal radiation would take a lot longer than the plant is exposed to vacuum in the movie, as you suggest. It really isn't exposed that long.

It always surprises me how many people think it would be hard to stay warm in space when, in fact, dissipating excess heat is far more of a problem.

And NO, David Brin, you can't dissipate the heat by shooting out lasers. No no no no no no no no.
posted by Justinian at 7:55 AM on July 9, 2008

I conjecture that the Axiom is parked in some kind of nebula containing plenty of nutritious Dark Matter. That, coupled with the bright light of newborn suns, keeps the plant healthy.
posted by drinkcoffee at 8:43 AM on July 9, 2008

IIRC, self-linking is OK in comments so long as it's relevant, right?

Well, I wrote a post on the Wired GeekDad blog that covers exactly this kind of thing.
posted by cerebus19 at 8:59 AM on July 9, 2008

flyingcowofdoom: "The plant was exposed to space for longer than 30 seconds. WALL-E shows EVE the plant immediately after surviving the pod implosion, but then they "dance" for at least a minute or two. Sure, he put the plant back into his body compartment, but unless he has a life support system in there that would re-pressurize after being opened in space the conditions wouldn't be any more favorable."

As I recall, EVE sucked up the plant in her little blue tractor beam and stored it inside of herself. Perhaps that storage compartment is specially designed to protect plant life in harsh conditions, considering that her whole purpose is to retrieve and deliver it safely to the Axiom?
posted by Rhaomi at 11:57 AM on July 9, 2008