isn't it rather presumptious to say that all life is carbon based?

Question

isn't it rather presumptious of us to say that life can't exist on other planets just because those planets don't have what we humans deem neccessary for it?

Answer 1

Yes and no. Life as we know it can only be carbon based. There are some folks at NASA who think about this all day long and have developed theories on silicon, nitrogen, sulfur, etc. based life forms.

Answer 2

It's entirely correct to say that all life WE HAVE EVER SEEN is carbon-based.

As for the rest of the universe, it seems rather likely.  The next element with similar chemical properties is silicon, and silicon just doesn't form the kind of molecules that carbon does.  We can make silicone (silicon-oxygen) polymers but they do not form naturally the way carbon chains do.  Radio astronomers have even found emissions from simple sugar molecules from deep space!  Nothing like it has been detected from silicon.

On top of this, the conditions which silicon life would probably need are far less likely than those of carbon-based life.  So, until we find something else or have good reason to expect to find it, the claim is reasonable.

Answer 3

First, everything we have seen so far is carbon based, so empirical evidence in is our favor there.

Second, experiments with silicon have shown that while silicon can create very complex molecules, the temperature range for silicon based organic molecules to be complex enough yet also reactive enough is too narrow, so silicon life might be possible, but it would probably only be stable under laboratory conditions.

Third, the major reason for life to be carbon based is that carbon has a particular energy gradient associated with most of its compounds, and no other atom shows this as well as complexity. While it might be possible for life to breath methane or drink ammonia in some extreme environments, it would still, in the end, be carbon based because carbon is such a versatile atom.

Some people have theorized about plasma based or neutron-star-based life, but until we have more data, that is pure speculation.

Answer 4

Carbon based life is deemed as the most likely form because of the great variety of different carbon based chemicals, and the fact that carbon is much more commonplace than other reactive elements.

The other reactive elements have inherent limitations relating to having too narrow a temperature range between reactivity and instability, or too small a number of other co-reactors or co-reactors that can interact within the thermal range of some kind of liquid, no, a solid wouldn't allow the initial mixing needed for bio genesis.

Answer 5

Hmm - you are correct in a way - but, they should have some element that is stable like Carbon for us. Where ever in the universe, the periodic table should be true ya? It cannot change from planet to planet or Galaxy to galaxy or may be universe to universe. may be there are silicon based life forms - who knows - but what is important is for the atom formation to be stable.

Answer 6

there may other lifeforms based on other elements, all life on earth is carbon based. there is a vast ocean on europa, a moon of jupiter may have life, who is to say it can't be silicon based

Answer 7

The Horta is silicon based.

Answer 8

All "life as we know it" is carbon-based.