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[Steven Novella]

marco - there is a flaw in your reasoning in that it only applies to a dominant genetic disorder.

However, for a recessive disorder the number of recessive alleles removed from the gene pool by manifesting the phenotype is often negligible.

In other words - there would be many carriers out there - hundreds or even thousands of carriers for every child of two carriers that get a double dose of the gene and are then born with the negative trait, in this case no vagina.

Also - take a look at these incidence rates for various severe genetic diseases
http://www.gig.org.uk/education3.htm

1 in 5k is right in the middle.

[Trinoc]

The energy stored in the stocks is part of the total potential chemical energy stored in US biomass. The total energy stored in the US by this method, which includes all of the crops, forrests, wild plants, algae.... every photosynthesizing organism is the US!..... is less than our annual fossil fuel use. I am using that as a simple reality check for people who promote biofuels.

So far of course we are only talking about conventional crops/plants growing outside in fields. Do you have any figures comparing solar cells and other purely physical means of extracting the energy with ideas such as concentrated sunlight reflected onto columns of algae?

Doing some back of napkin engineering. You could use calcium hydroxide  to capture CO2 from a moving column of air and then heat it to release the CO2. The energy required would be (largely) that to circulate the air plus the heat energy required to raise the calcium carbonate to the temp where Calcination happens. I would assume that the bulk of that energy would be used for heating. It would require roughly 1.2 MJ to raise a kg of calcium carbonate by 800 degree C.  Because CO2 is just under half the mass of the original Calcium Carbonate we should more than double the energy per kg.

Lets say that leaves us with 5MJ per kg. That is way less than the 600 to 800 MJ per kg that plants require to remove the same amount of CO2.

Anyone want to check the reasoning and math?

There are plenty of chemical reactions that absorb CO₂. Virtually any alkali will do, and there are also more efficient and more easily reversible reactions -- using amines, I think -- which are proposed for use with power station flue gases.

What I don't know is how effective any of these absorbers are at extracting CO₂ at around 400 ppm rather than the high concentrations in flue gases. At the very least you would have to pump a tonne of air (about 1000 cubic metres) through the reactor to extract every 400 grams of CO₂ (around 110 grams of carbon), even assuming the reaction extracts 100% of the available CO₂ every time. Have you taken the size of the plant and pumping energy needed into account in your calculations?

[craig]

The energy stored in the stocks is part of the total potential chemical energy stored in US biomass. The total energy stored in the US by this method, which includes all of the crops, forrests, wild plants, algae.... every photosynthesizing organism is the US!..... is less than our annual fossil fuel use. I am using that as a simple reality check for people who promote biofuels.

So far of course we are only talking about conventional crops/plants growing outside in fields. Do you have any figures comparing solar cells and other purely physical means of extracting the energy with ideas such as concentrated sunlight reflected onto columns of algae?

Doing some back of napkin engineering. You could use calcium hydroxide  to capture CO2 from a moving column of air and then heat it to release the CO2. The energy required would be (largely) that to circulate the air plus the heat energy required to raise the calcium carbonate to the temp where Calcination happens. I would assume that the bulk of that energy would be used for heating. It would require roughly 1.2 MJ to raise a kg of calcium carbonate by 800 degree C.  Because CO2 is just under half the mass of the original Calcium Carbonate we should more than double the energy per kg.

Lets say that leaves us with 5MJ per kg. That is way less than the 600 to 800 MJ per kg that plants require to remove the same amount of CO2.

Anyone want to check the reasoning and math?

The process that you describe only removes the CO2 from the air and concentrates it.  It doesn't convert it into fuel of any sort.

To make the comparison to plants more equivalent you would have to chemically reduce the CO2 to carbohydrates.

[b2theory]

The energy stored in the stocks is part of the total potential chemical energy stored in US biomass. The total energy stored in the US by this method, which includes all of the crops, forrests, wild plants, algae.... every photosynthesizing organism is the US!..... is less than our annual fossil fuel use. I am using that as a simple reality check for people who promote biofuels.

So far of course we are only talking about conventional crops/plants growing outside in fields. Do you have any figures comparing solar cells and other purely physical means of extracting the energy with ideas such as concentrated sunlight reflected onto columns of algae?

Doing some back of napkin engineering. You could use calcium hydroxide  to capture CO2 from a moving column of air and then heat it to release the CO2. The energy required would be (largely) that to circulate the air plus the heat energy required to raise the calcium carbonate to the temp where Calcination happens. I would assume that the bulk of that energy would be used for heating. It would require roughly 1.2 MJ to raise a kg of calcium carbonate by 800 degree C.  Because CO2 is just under half the mass of the original Calcium Carbonate we should more than double the energy per kg.

Lets say that leaves us with 5MJ per kg. That is way less than the 600 to 800 MJ per kg that plants require to remove the same amount of CO2.

Anyone want to check the reasoning and math?

The process that you describe only removes the CO2 from the air and concentrates it.  It doesn't convert it into fuel of any sort.

To make the comparison to plants more equivalent you would have to chemically reduce the CO2 to carbohydrates.

Agreed. However, that isn't the point. In that last post I was simply putting together an educated guess as to how much energy is required to remove a given amount of CO2 from the air. Since I already know that it requires the plant to capture 800 MJ for every kg of CO it removed from the air and I am only using 5 MJ/kg, I have another 795 MJ of energy with which I can use to electrolyze water and cook it's Hydrogen with my newly acquired CO2 to produce a gasoline-like fuel with an energy density of 40MJ per kg. I doubt that such a process is only 5 percent efficient.

[Cpolsonb]

I always find the "how do you know the great wall of china exists" analogy hilarious when I see it repeated (or things in it's style). I propose a new term known as an "U.nidentifed F.oreign O.bstacle" 

Check out my blog for the lastest sighting of this new kind of UFO!

P.S. Sorry about whoring my blog twice in the same show notes 

[seaotter]

I for one love it when you skeptics find my sacred cows. I hate those fucking parasites. I just found one on the quack cast a coupla weeks ago. I took for granted that mold caused all sorts of disease in your house. I celebrate when these unsupported beliefs get exorcised. Ridicule? Bring it on! I can take it!

Agreed. Mold and Aspartame were both things that I had just accepted as bad, without any real evidence. Two years ago I was an electrician on a jobsite that was shut down because of black mold that had started to grow on the sheetrock from water damage. The aspartame issue was one that I remember hearing for the last decade and being as lazy as I was I never bothered to question it. Feels good to start a new week with two less cows on my back. Plus, now I can add some diet root beer back into my diet.

At least I'm not the only one who thought there was something suspicious about aspartame.

What is the deal with black mold? From looking around on the internet it does seem to be a health issue.

http://www.quackcast.com/spodcasts/files/podcast_24.mp3

[Voodoo Rage]

I always find the "how do you know the great wall of china exists" analogy hilarious when I see it repeated (or things in it's style). I propose a new term known as an "U.nidentifed F.oreign O.bstacle" 

Check out my blog for the lastest sighting of this new kind of UFO!

P.S. Sorry about whoring my blog twice in the same show notes 

It's such a ridiculous analogy and it does expose the inherent flaw in almost all non-skeptical believers; that any belief has validity just because you personally want it to be true (evidence is never part of the equation). I hear that in religious debates all the time, "Well I KNOW that MY religion is true because I just do."

[The Dicklomat]

...I hear that in religious debates all the time, "Well I KNOW that MY religion is true because I just do."

Whenever I encounter someone who takes the attitude that something is true because their instinct or gut tells them that it is, I show them "The Monty Hall Paradox" (which Brian Dunning referred to in "S or F"), ask them what they would do (they ALWAYS say it doesn't matter) and then I tell them that they are better off switching and show them a simpe mathematical proof demonstrating why.

Most of them then tell me it's a math trick (like the supposed "Achilles vs the Tortise Paradox"), but then after I make them put money on it (suckers!), I show them another more convincing demonstration (the idea for which I got from quip Bob Novella made on a show a couple of years ago) using a lottery ticket metaphor that ALWAYS convinces them to switch.

On rare occasion, the result has been that the person who once put so much faith in their "hearts" on other things then think twice before they do so again.

BTW - I used this little trick last year to wager my boss into giving me the time off I needed to go to TAM7.  He was soooo confident that it was a sure thing that he wouldn't even let me put anything on the table except to stop asking for time off.  He is much wiser now...