Robotic life-forms have been mentioned earlier in this forum. Just remember the 3 Laws of Robotics:
1. A robot may not harm a human being, or, through inaction, allow a human being to come to harm.
2. A robot must obey the orders given to it by human beings except where such orders would conflict with the First Law.
3. A robot must protect its own existence, as long as such protection does not conflict with the First or Second Law.
In Asimov’s Robot books machines started to become more human and expanded the meaning of artificial intelligence. This is speculative sci-fi but if robots develop feelings they can be considered aliens too. Biorobotics is the study of making robots emulate or simulate biological organisms. And clones can be considered aliens, too. If you know the story “Island of Dr. Morreau,” he engineered clones, mixed their genes with animal DNA (recombinant DNA), and then they became not human anymore.
@Imperious:
I like the idea that the planet Mercury actually may have ice at its caps. If you move further south eventually a barrier of say 100 miles exists where the temp goes to 600 degrees. I wonder if life can be sustained in the “in between region”
It can’t, it’s too close to the sun
@Gen:
If you know the story “Island of Dr. Morreau,” he engineered clones, mixed their genes with animal DNA (recombinant DNA), and then they became not human anymore.
That is the movie with Val Kilmer. In the short story by H.G. Wells, the “beasts” were all created by vivisection… he CUT them to make them Human.
@Gen:
Uh, yeah, but that would be a totally alien species. Scientists don’t think it’s possible to have hydrogen or helium-based organisms… Just imagine–hydrogen is the lightest element and helium is not abundant enough!
The term “carbon-based” is just a reference to the fact that carbon can form long, long chains, like in DNA. I don’t remember ever hearing that hydrogen or helium have this characteristic as well, but I do think silicon can… However, I do know that helium is certainly abundant enough. If the Big Bang is correct, (and it is the leading theory as to the beginning of the universe) then helium makes up about 20% of the universe. And with the sky being loaded with billions of stars, that is a huge amount!
And that is the concept behind the Sci Fi stories…
Carbon is rather rare in the universe, but life developed based on it. If life formed in the case of this rare set of circumstances… (carbon in large quantities, specific temp, specific high energy source, etc.), then perhaps a related chain of events led to life with somethign far more common…
And Helium is not THAT out there… stable, exists in one of the HIGHEST energy environments known, with an abundance of radiation to allow for mutation…
I’ve just read that hydrogen and helium are the most abundant elements in the universe. (stars) Stars begin by burning hydrogen via fusion, and then when all their hydrogen fuel runs out, having been fused into helium, then the stars will simply begin burning helium. By the way, supposedly when that happens in our solar system, in about 5 billion years, then the sun will puff up dramatically, enough to engulf the Earth’s orbit. :cry:
Actually, I don’t have a periodic table in front of me right now, but isn’t helium one of the Noble Gases? That would mean that it is IMPOSSIBLE for any helium-based life-forms, since the Noble Gases’ valences are so low, (zero) that they don’t ever bond with anything else.
Except themselves…
@ncscswitch:
Except themselves…
I don’t know if that’s true… I thought elements with noncovalent bonding can’t bond with anything, even themselves
An element’s valence just means how many available “slots” it has with which to form covalent bonds. So I might just say that they can’t even bond with themselves either.
The available bonding slots has a lot to do with whether you can get life out of molecules. Hydrogen has a valence of 1 (one slot), so you can only bond it to one molecule. Oxygen has a valence of 2, Nitrogen has a valence of 3, and Carbon has a valence of 4. Silicon also has a valence of 4, which is why Silicon is considered as a possibility for forming life. Having a valence of 4 means that you can bind the maximum number of atoms to the atom, and can form all kinds of chains. Helium is a noble gas, so it is most stable not bonded to anything.
Another factor is whether you have a solution in which reactions can take place on the base molecule. Water happens to be the perfect solution for carbon based reactions to take place, which is why scientists look for water when they are looking for life.
Yes water is useful because it has a neutral pH, and also due to its continued dissociation between hydroxyl and hydrate ions
