OT: Carbon Dioxide races -> known vs unknown -> terraforming mars -> is or is not

[narf poit chez BOOM]

small correction - Last i heard, photon's where 2000 times the size of an electron.

i saw quarks and basically started blabering. or should that be 'firmly speaking my mind without taking a good look around first?'. but, since i don't seemed to have annoyed anyone and was at least partly on topic, i'll leave it there.

[Fyron]

Then you heard wrong. Photons are much much smaller than electrons. In fact, they are what electrons use for gaining and losing energy.

[Suicide Junkie]

The effective "size" of a photon is proportional to its wavelength.

Microwaves, for example, have wavelengths of from 10th of a millimeter to 10 centimeters... hence the size of the view holes in your microwave door.

[Fyron]

Well, I was more referencing the particle nature of photons than the wave nature...

And as you know, electrons have a wave nature too, so they are technically much bigger (in wave form) than their particle nature would indicate.

[ July 18, 2003, 02:27: Message edited by: Imperator Fyron ]

[Andrés]

Some related question:

But it would be plausible for life, even if they breathe oxygen, to evolve in an atmosphere that is toxic or unbreathable four us, perhaps combined with different G, pressure, temperature, ect...
For example the 70% N2, ~26% O2, ~4% CO2 atmosphere Dogscoff had suggested would not be healthy for humans, but perhaps perfectly fine for an alien species.
That would have similar effects in a sci-fi story without the need of unrealistic chemistry.

What about silicon based lifeforms? Are they possible? Would they have different requirements and tolerances than carbon based life?

In the Star Wars universe there are a few cyanide-breathing aliens, whose atmosphere is as deadly for us as our oxygen-rich atmosphere is deadly for them. Is there any hint of realism here?

[geoschmo]

I think without question that is possible Andres. It's entirely plausible to imagine a lifeform that follows the same basic rules but living on a world that is too hostile for us to survive. There are many lifeforms on earth that thrive in areas humans are unable to.

I wonder though if a person that breaths oxygen and is immune to the effects of cyanide for example because of their home environment would simply tolerate the cyanide, or develp some actual need for it. That would be the determining factor in whether they would need special aparatus to visit earth like worlds.

Geoschmo

[Fyron]

There are organisms that can live in very human-toxic environments on earth, so that is possible. But, most of them are very simplistic monerans, so it gets iffy whether more complex organisms can form in them (esp. in conditions that are extremely harmful to life in general). They can survive partially because of their simplicity; there is not much to go wrong, so not much protection had to evolve.

There actually are some silicon based lifeforms on earth. They are monerans (bacteria), so nothing too complex. But, I am not sure if silicon can perform as efficiently as carbon for more complex organisms. It might be possible though. Of course, that is the only other element that complex natural (ie: non-robotic) life could be based on, as it is the only other element capable of forming hugely complex molecules (100s to 1000s of atoms) as carbon can (though it does not do it as well). Such complex molecules are necessary for natural lifeforms.

[ July 18, 2003, 19:06: Message edited by: Imperator Fyron ]

[macjimmy]

This reminds me of something I once read about atmosphereic formation on earth. Seems like a different atmosphere on a planet could be a function of its age, or if it has life or not. IIRC, earth's atomsphere was a highly toxic combination of volcanic gases and such before early single celled life "terraformed" earth into the oxygen-enriched enviroment we have today.

[Loser]

Originally posted by Imperator Fyron:
There actually are some silicon based lifeforms on earth.

Are you sure of this?

I would be most pleased to see a link to information on this. It would be really fascinating.