One off Silicon based humanoid...

[Aquinas]

This race never got a name but, way back in the early eighties, a member of the race was discoved in a small ship in the Domain of Illelish. The only inhabitant was a humanoid grey skinned creature who identifed itself as Xirtam.

Scientific examiniation revealed it (gender was never clearly established) to be a complex silicon based being.

Xirtam was found to be intollerant of high temperatures and energy weapons although the high mohs rating of his skin rendered him highly resitant to kinetic energy.

He was inducted into the Illelish Guard and recieved Imperial citizenship. He showed great skill as a military commander, although his ruthlessness did not indear him to many of the troops under his commmand.

He remained popular with the Archduke however and was appointed Colonel of the Illelish Guard with the rank of Brigadeer General.

He recieved other staff promotions eventually becoming Marshal of Illelish; he was assassinated by a high powered laser two years after his promotion.

No other members of Xirtam's species have been encountered in Imperial space and there is no record of their existence anywhere.

Vidmar

 

[pauldrye]

Originally posted by Vice-Admiral Vidmar Kulkinski:
Scientific examiniation revealed it (gender was never clearly established) to be a complex silicon based being.

What did he eat? Seriously.

Silicon biochemistry is problematic for a couple of reasons. Let's see:

- Straight silicon is too rigid for biochemistry except at high temperatures. Try siloxane, which is "silicon-based", but alternates Si-O-Si-O as the replacement for the carbon chain. You get silicones out of that, and they're much better suited for the purpose.

- Not to be indelicate but his, er, "digestive gas" is going to be mostly silane (replace the carbon in a methane and you get silane). Silane explodes in contact with air at room temperature. I trust you see the problem....

 

[Aquinas]

Ah well...

I was only 12 at the time... Shame I didn't know about his "digestive gasses" puts Rigel's Helium farts to shame.

I thought that silicon was only stable at low temps tho? That's why I made him vulnerable to lasers and plasma/fusion weapons (actually I was just lasers then as Book 4 hadn't come out)

So we'll just lose Marshal Xirtam in the what might have been file (may be use him in Space Opera)

Vidmar

 

[Rahnd]

I dont exactly remember my chemestry, but wouldent a silicon baised liform breath a gas other than oxogen? I am cant remember what it is. but do to the silicon and not carbon, his body would use a different combustable instead of O2?

 

[Rahnd]

To add to that, a silicon baised species still would be very workable and quite cool(find a different name though, i wont hold the one you made up against you, you were 12). I would just imagine cost of living would be a bit higher, and a some sort of resporator would be nessasary.

 

[pauldrye]

Originally posted by Rahnd:
I dont exactly remember my chemestry, but wouldent a silicon baised liform breath a gas other than oxogen?

No particular reason he would. The point of silicon is that it is chemically very similar to carbon, and quite common, so you just substitute it into the molecules for the carbon and end up with something fairly similar.

However, subsituting for oxygen is more problematic. All the elements chemically similar to it are solids at anything like room temperature. Sulfur doesn't turn into a gas until you hit 445 Celsius (and that's a one atmosphere -- if you immediately thought "Venus", the high pressure ups the boiling point).

The others (selenium, tellurium, and polonium) are even worse. 685, 988, and 962 Celsius, respectively. Hydrogen selenide is amazingly toxic to human, and pure polonium is both amazingly toxic and radiactive to boot. All are quite rare too, so the possibility of an atmosphere consisting of any of them is remote.

 

[Rahnd]

What makes the odds remote?

 

[pauldrye]

Originally posted by Rahnd:
What makes the odds remote?

Take a look at the Earth's atmosphere as an example:

Nitrogen
Oxygen
Argon

All three are relatively common in the universe:

Nitrogen: 6th most common element
Oxygen: 3rd most common
Argon: 11th most common

On the other hand:

Selenium: 34th
Tellurium: 52nd
Polonium: 84th

Each is many, many times less common than even Argon (in fact, the total number of atoms of *all* elements from number 12 to 92 put together are only twice that of argon alone. And argon is fifty times less common than nitrogen, which is seven times less common than oxygen).

To put it simply, there aren't enough atoms of Selenium, Tellurium, or Polonium around to make atmospheres out of.

On top of that, remember that they're chemically similar to oxygen, so in any situation where you wanted to use them, you'd need to explain where all the oxygen went (millions of times more common than polonium, for example) so that it isn't muscling in on the biological reactions that use your odd elements. Biochemical similarity is a problem in a lot of cases: it's why carbon monoxide is deadly, for example. It bears a resemblance to the O2 molecule in the air, and hemoglobin actually likes it better than 02. So it displaces the oxygen, and we suffocate....