Where DID all the oxygen come from?

Author: Holly Published: August 19, 2010 3 comments

Passing Gas is an excellent intro for both adults and kids on where the air you breathe comes from, and has a couple of funny surprises.

Whether you’re interested in the “climate change” debate, are a homeschooler, are a parent of a middle-school or high-school science-age student, or would simply like to know the answer to the question, I highly recommend the few minutes it will take to watch this.

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About the author: Novelist, writing teacher, on a mission to reprint my out-of-print books and self-publish my new ones.

3 comments… add one

Lionel Davoust Aug 28, 2010 @ 8:57

As an ex-scientist, ex-oceanobiologist, I have to say I find the video’s conclusions extremely flawed. The facts are sound, the perspectives are not. Yes, there is a kind of uncertainty about the causes of global change, but caution has to prevail in such a matter. More importantly, the catch-22 argument about plant life in the end is total nonsense.

YES, plants do use CO2 to fuel photosynthesis, but that’s only one part of the argument. Plants do BREATHE too, that is take it O2 to fuel their metabolism, just as we do.

Very roughly:
PHOTOSYNTHESIS: use CO2 + light and chemical components to manufacture sugars (akin to what we do when we eat). Excreting mainly O2 in the case of plants. (In biochemistry: Calvin cycle)
BREATHING: use O2 to break down sugars to fuel the living being’s activity (growing, reproducing etc.) (Krebs cycle)

A plant without O2 will die as surely as us. This argument does not hold.

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Danielle Aug 20, 2010 @ 10:45

Not relevant to this, but veeeery interesting Tip email from you today. Once again, you have lit a lamp that shed a different light on my writing.

And I now have no interest in watching “The Day The Earth Stood Still” (either version of it.) 😀

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Astropolis Aug 19, 2010 @ 18:22

Actually I’ve used this sequence of reactions as the basis for some of my terraforming stories. Essentially the idea is that there are plenty of planets with the pre-life chemistry, all the colonusts need to is seed them with algae from orbit, then wait:

Our first goldfish – we called him Thor for obvious reasons – had survived the process and become a pet. We’d promised him a pond of his own, and a lady goldfish, just as soon as the terraforming advanced far enough to let him breathe. There was a natural pond only a hundred yards from where we’d landed and every week we analysed the water. It had started off with enough dissolved ammonia to work as a highly effective bleach. But as the terraforming reactions kicked in hard the atmospheric ammonia was fixed into the soil and the reducing gases, mainly hydrogen and methane, went down fast. There was more and more carbon dioxide, day by day, until the morning when the digital Orsat announced the first oxygen.

Then the race was on. When would the dissolved oxygen in the pond get up to the point that Thor could be released?

He didn’t make it. As the atmosphere went through the high carbon dioxide phase, before the carbon got trapped in biomass, we had a greenhouse period. The temperature went way up and everyone on the ship started discarding clothing. Thor went up to one end of his tank and sulked for three days before we realised that goldfish don’t handle hot water very well. By the time we’d got some ice in his tank he was badly stressed, and he died a week later. Of course we thawed another Thor – we called this one Frosty – but he wasn’t the same.

We gave Thor a proper burial. We got the core drill and went down to a decent depth, then dropped him in and backfilled.

And that’s why the grave of the first colonist to die on Homeworld is six feet deep, but only four inches across.

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