Peter’s answer to “Scientific question - please do not read if you have not already read the book! : : : One of th…” > Likes and Comments
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Thanks for answering. I must have overlooked this information. Follow up question: when the Hail Mary is 100% O2, then why did he need the oxygen mask when he was injured?
To give him more oxygen, the same reason why we would on earth. Assumingly the mask supplied oxygen at a higher pressure.
In chapter 8 he finds some hard paraffin and "with some poking, open flames, and mild swearing.." how could he do this in a 100% O2 environment?
I have not been able to find a reference to the % of O2 in the book can you please provide at least a chapter reference?
@Mike G: when he goes out for the EVA to fetch the cylinder in chapter 7: "Interesting. I didn't have to go through a decompression step. ... Apparently, the entire Hail Mary is at that 40 percent pressure." there is another place where it get's clear it's pure O2. Pure O2 with lower pressure behaves pretty similar to normal atmosphere in regards of how quick paraffin will burn. (admittedly 40% O2 is still more than what we have)
contradicting that later in chapter 16: "Xenonite ... separates my one-fifth atmosphere of oxygen pressure ..." 20% O2 makes even more sense than 40%
Flammability involves more than the simple fire triangle of O2, fuel, & ignition when you're dealing with a closed system such as the Hail Mary. Pressure and temperature also play roles in the equation with an inverse relationship between pressure and lower flammability limits (LFL).
What I find more frustrating is the inconsistencies in ship pressure as mentioned by Peter P. In addition to his quoted observations, there's a comment regarding the ship's emergency systems engaging when pressure is >0,33 atm, which contradicts the inference of 0.4 atm mentioned in chapter 7 just before the first EVA. My guess is that his editor (and beta readers) didn't pay much attention to the science leaving that to Weir's expert sources to figure out.
current american space suits operate at about 0.3 atm and pure O2. Russian suits operate at about 0.4 atm and pure O2
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Heike
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May 07, 2021 07:49AM
Thanks for answering. I must have overlooked this information. Follow up question: when the Hail Mary is 100% O2, then why did he need the oxygen mask when he was injured?
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To give him more oxygen, the same reason why we would on earth. Assumingly the mask supplied oxygen at a higher pressure.
In chapter 8 he finds some hard paraffin and "with some poking, open flames, and mild swearing.." how could he do this in a 100% O2 environment?I have not been able to find a reference to the % of O2 in the book can you please provide at least a chapter reference?
@Mike G: when he goes out for the EVA to fetch the cylinder in chapter 7: "Interesting. I didn't have to go through a decompression step. ... Apparently, the entire Hail Mary is at that 40 percent pressure." there is another place where it get's clear it's pure O2. Pure O2 with lower pressure behaves pretty similar to normal atmosphere in regards of how quick paraffin will burn. (admittedly 40% O2 is still more than what we have) contradicting that later in chapter 16: "Xenonite ... separates my one-fifth atmosphere of oxygen pressure ..." 20% O2 makes even more sense than 40%
Flammability involves more than the simple fire triangle of O2, fuel, & ignition when you're dealing with a closed system such as the Hail Mary. Pressure and temperature also play roles in the equation with an inverse relationship between pressure and lower flammability limits (LFL).What I find more frustrating is the inconsistencies in ship pressure as mentioned by Peter P. In addition to his quoted observations, there's a comment regarding the ship's emergency systems engaging when pressure is >0,33 atm, which contradicts the inference of 0.4 atm mentioned in chapter 7 just before the first EVA. My guess is that his editor (and beta readers) didn't pay much attention to the science leaving that to Weir's expert sources to figure out.
current american space suits operate at about 0.3 atm and pure O2. Russian suits operate at about 0.4 atm and pure O2
