Sci-Fi impossibilities...

[johnmiic]

Issac Asimov put this forward in his Foundation and Earth novel. He proposed that the reason why the plants and animals in that story were the same on human inhabited planets was because the original settlers brought them there. While it makes sense that's just one theory tho. Plants are simple life forms. I expect there are similar plants on similar Earth-like worlds. Animals being more complex might vary wildly.

[Brazoo]

That's actually not true. The same basic elements which make up our planet are found throughout the universe, so it stands to reason that wherever similar conditions exist, (temperate climate, proximity to the sun, etc.) That elements will combine in the same way. For example, Mars is red because iron oxidized on it's surface the exact same way it does on Earth...you have the exact same chemical reaction occurring millenia apart on two different planets with two extremely different climates. Even here on Earth carbon-based life has developed in environments even more inhospitable than some planets, such as the sea worms living in toxic near-boiling water next to volcanic vents.

Yeah man - it's one of those mysteries where the answer actually gets more and more complicated the more we learn, which makes it incredibly frustrating. In fact if I had to pick choose ONE thing for science to answer in my lifetime - that might be it.

On one hand it seems incredibly unlikely that alien life would just happen to evolve in a similar way to the way life evolved on Earth, given all the random possibilities that are left up to chance during the whole process.

On the other hand life might always be predisposed to evolve similarly to how everything evolved here. For example, here evolution seems to favor symmetry for most animals (two eyes, two ears, four limbs...) but then there's things like sponges just to mess our neat little way of perceiving things up.

Last year NASA announced that they found a bacteria that used arsenic as one of it's building blocks - which would have had HUGE implications, but it seems now like they were wrong about their findings. All the later experiments (as far as I know) failed to produce the same results. If it was true it would have implicated that life started twice on earth instead of just once. It would be great if we could synthesize or manipulate bacteria genetics enough as a proof-of-concept for things like this though - to help answer the question. Aside from finding an alien being that might be the only way we could figure this out better.

I was listening to a science podcast a while ago, and the host wondered which would be more incredible: If we found alien life and it had alien DNA or if it had AGCT based DNA like everything on Earth did. Both possibilities are mind blowing for different reasons. It kinda hurts my head a bit.

I think in most cases sci-fi isn't as creative with alien life as it could be. Most aliens just seem like variations on what life is like here.

[johnmiic]

If it was true it would have implicated that life started twice on earth instead of just once.

If the theory of how the Moon was created, (a planetoid crashing into the young Earth), holds up then life may have started in one way, was wiped out, and reset after the Earth cooled again.

[Brazoo]

If the theory of how the Moon was created, (a planetoid crashing into the young Earth), holds up then life may have started in one way, was wiped out, and reset after the Earth cooled again.

I guess it's possible that there were parallel strains of life formed that were destroyed in some way - that we could have no evidence for now - and our strain survived and moved on. It's kind of an interesting sci-fi premiss for alien life too that I've never heard of being explored - someone uncovering not a new species, but a new life-form on Earth.

[Brazoo]

What I'm proposing is that they might have a very close equivalent, or an analog. That the patterns we saw here for evolution happen more or less the same on every planet with life, barring outside influence. So that common ancestor might be exactly the same, or slightly different, or completely different.... and that planet's equivalent of the hyena might have had a different ancestor altogether but evolved into something similar because it fit a niche.

Yeah - There are plenty of examples of convergent evolution - animals evolving similar traits independently from each other's evolutionary branches - Flight is an excellent example. Insects, birds and bats evolved for flight with totally different paths. So there's no way to discount the idea that life might just prefer certain configurations.

To me it all comes back to the building blocks and basic genetic structure. If life in the universe only has one basic chemistry to it that might limit the possibilities. If we're conceiving non-carbon based life then I think all bets are off.

Still, there are are so many possibilities even with our idea of carbon based life. Like, what if life evolved on a gaseous planet? Or a planet that doesn't get energy from a star? Take away some of our most basic evolutionary pressures like surface and our idea of up and down and that leaves things pretty open too, no?

[Brazoo]

When watching Star Trek Into Darkness, I thought the red stalky plant things they were running through at the beginning was kind of interesting. I imagine they're using something other than chlorophyll for photosynthesis, otherwise they'd be green. They seem like they'd use photosynthesis for energy, since they're growing like plants. Whatever the case, I'm pretty sure I'm being too much of a dork even thinking about it and J.J. Abrams was just like, "Red weeds! Awesome!" and that's about it.

Well, we do have red plants too - which got me wondering and searching so I found this:

http://www.nytimes.com/2013/07/23/science/how-does-a-plant-with-red-leaves-support-itself-without-green-chlorophyll.html?_r=0

Which basically says red plants have chlorophyll, but also produce another pigment that masks the green.

I didn't see the movie yet, I saw the opening and decided to watch it another time. My nerd brain was racing too much to drop my suspension of disbelief to enjoy it. (They dropped Spock in a volcano - they couldn't have just programed that device to go off without him? Why were Kirk and Bones on the planet? Spock is freaking out about the prime directive, but he's also about to freeze a volcano? This is for another time...after more alcohol.)

[Brazoo]

Getting off biology for a sec, here is one that recently happened to me:

I've always loved the opening of the cartoon "Thundaar the Barbarian" when the Moon splits in half, and lately a lot of post apocalyptic sci-fi movies have used a broken moon. I was cool with it, because it looked neat and reminded me of Thundaar, but recently I was listening to a podcast and they were complaining that seeing the Moon split in half was one of their pet peeves, because if an object that size was torn apart gravity would cause it to coalesce again almost instantly. Oh yeah...oops.

[ctc]

>If life in the universe only has one basic chemistry to it that might limit the possibilities. If we're conceiving non-carbon based life then I think all bets are off.

Definitely; but I think when it comes to a sci-fi story you HAVE to take stuff like that at face value. As presented by the story, 'cos that's the rules they're working by. In real life we can imagine all sorts of anythings 'cos we don't have a good sampling to go off of. But even then, the Earth has all sorts of weird little critters that defy our prior ideas about what life needs. ("Extremophiles" I think is the collective term.)

Don C.

[Brazoo]

>If life in the universe only has one basic chemistry to it that might limit the possibilities. If we're conceiving non-carbon based life then I think all bets are off.

Definitely; but I think when it comes to a sci-fi story you HAVE to take stuff like that at face value. As presented by the story, 'cos that's the rules they're working by. In real life we can imagine all sorts of anythings 'cos we don't have a good sampling to go off of. But even then, the Earth has all sorts of weird little critters that defy our prior ideas about what life needs. ("Extremophiles" I think is the collective term.)

Don C.

I'm not a HUGE sci-fi dude, outside of movies, I assume in a lot of novels aliens are little wilder because they can explain things deeper. In movies I tend to find aliens a little dull. I'd like to see a movie with an alien that looked ALIEN - an intelligent life-form that wasn't humanoid. I can see the limitations story-wise - for people to visually relate to these creatures without huge lengthy explanations you could do in a novel.

[ctc]

>In movies I tend to find aliens a little dull.

I imagine a lot of that is because of the limits of budget and effects technology. That's what makes me sad about CGI; we can finally do ANYTHING, and we choose to make stuff that looks a lot like everything else.

>I'd like to see a movie with an alien that looked ALIEN

That's one reason I like cartoons so much; you see some weird stuff. I remember reading about the animated Trek episode "BEM;" that they wanted an alien that split like that in the original show, but couldn't pull it off convincingly with the effects of the day.

>they were complaining that seeing the Moon split in half was one of their pet peeves, because if an object that size was torn apart gravity would cause it to coalesce again almost instantly

....but the mutants, wizards and thousand year old technology that still worked was okay? (AND the fact that Gemini claims to have used the novel "Frankenstein" as inspiration for one of his monsters, even though the method used is from the film....) This is why I think it's fun to discuss such things, but not get too wrapped around the axle over them. Maybe it was a magic comet, hence the proliferation of paranormal powers afterwards.

Don C.

[Brazoo]

>they were complaining that seeing the Moon split in half was one of their pet peeves, because if an object that size was torn apart gravity would cause it to coalesce again almost instantly

....but the mutants, wizards and thousand year old technology that still worked was okay? (AND the fact that Gemini claims to have used the novel "Frankenstein" as inspiration for one of his monsters, even though the method used is from the film....) This is why I think it's fun to discuss such things, but not get too wrapped around the axle over them. Maybe it was a magic comet, hence the proliferation of paranormal powers afterwards.

Don C.

Sorry, maybe I didn't explain that clearly. They weren't complaining about Thundaar, they were complaining about all the recent movies that used that image. Movies that are trying to seem more plausible scientifically than Thundaar. "Oblivian" is the first one that comes to my mind, but there was about 5 they mentioned (possibly the last Star Trek, but I can't recall). Apparently its popular to throw a broken moon into movies now.

Also, this was in a science podcast where they specifically review movies for the science - it's meant to be educational but light hearted. It's cool to me because just like Torgopizza was saying it makes you think about things differently.