View Full Version : Why Silicon-based Aliens Would Rather Eat our Cities than Us: Thoughts on Non-carbon

2011-Dec-01, 02:50 PM
Editor’s note: Bruce Dorminey, science journalist and author of “Distant Wanderers: The Search for Planets Beyond the Solar System,” interviews NASA astrochemist Max Bernstein for Universe Today about the possibility of Silicon-based life. Conventional wisdom has long had it that Carbon-based life, so common here on earth, must surely be abundant elsewhere; both in our [...]

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2011-Dec-01, 05:49 PM
My first thought when I hear the phrase "silicon-based aliens" is robotic aliens based on silicon semi-conductor circuitry. Maybe such aliens would rather "eat" silicate atmospheres (http://iopscience.iop.org/1538-4357/703/2/L113/fulltext/apjl_703_2_113.text.html).

2011-Dec-02, 10:03 PM
I'm sure a lot of animals would prefer eating atmosphere as well. Plants could be seen as "eating" atmosphere, but animals eat based less on the building-block value of their food than on the energy content of their food. Do silicate atmospheres have more chemical energy than silicate buildings do?

It's a bit silly, in any case. Oil is organic and has high energy content, but that doesn't mean that we can eat it.

My first thought with "silicon-based" is 2nd gen life too (reproducing machines), but it's an interesting thought-- are reproducing robots really going to be described as silicon-based? The closest we've got so far is through using a bunch of carbon. (I have no knowledge of alternate computing technologies, and I guess electronics are the hard part now.)

Is there some reason that life couldn't use both silicon and carbon? Is it a case of anything sili-can do, carbon do better?

2011-Dec-05, 08:46 PM
Silicates have no significant chemical energy, but that's not really a problem. Silicate atmospheres only exist on extremely hot worlds which are close to the parent sun. As such, there's plenty of solar power.

In theory, anything silicon can do carbon can do better. In practice, our digital technology is heavily based on silicon, rather than diamond or graphene. Currently, at least, the forms of carbon suitable for high performance digital electronics are expensive and difficult compared to silicon technology.

So, it's possible that technological aliens may find it easier to develop silicon based machines than carbon based machines.