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Comment by VLM | Hacker News Reader

"So if you made a human that did this, you would have a human that could refrain from eating much food for energy and instead choose to hang out in a nuclear reactor"

There may also be a surface area to volume argument that radiation could support a 200 pound pile of fungi, but only as long as the average thickness of fungus (or human) is less than 1/4 inch for maximum adsorption rate.

Also specific power per gram of fungi is probably pretty low compared to my leg muscles.

It would probably be more efficient to use the reactor to generate (eventually) visible light and use that and good old chlorophyll although that runs into the surface area/volume thing again where extensive past discussion shows all it really does is slow down starvation a couple percent. Chlorophyll is ridiculously inefficient.

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That's a good point. Gamma rays are pretty penetrating though, so unlike visible light there might be some benefit to having a rather thick piece of flesh to absorb as much gamma rays as possible, instead of letting most of them pass through the skin then get uselessly absorbed by muscle and organs.

I think you are dead on with the power consumption point though. The human body uses something around 100 watts or so right? (That might just be how much they put off in waste heat, I'm not really sure... but in the neighborhood of a few hundred watts I guess) You would need to put out way more than that in gamma rays to power the person, taking into account waste at various stages. I suspect you'd cook a human before you managed to power one.

I had a strange weird idea about all this, you might not be able to generate enough power to do mechanical stuff, but I wonder if you could power nano-robots and micro power bio-telemetry gadgets using this? The problem with magnetic fields is the area of the pickup coil of something the size of a blood cell is so small.

You couldn't do anything bulk physical, but you might safely generate enough power to do ultra low power telemetry. Like hold this piece of natural granite to activate the glucose monitor sensors in your hand's blood vessels walls or something.

Or using a really good switching power supply like design you could eat a banana, all of which are somewhat radioactive, and some sensor could very slowly charge up for an hour (or a day, or a week...) and then use all that power in a millisecond to squeak out your blood pressure to your phone.

Something good might yet come of this. Probably not this decade, maybe this century though.

If somebody at YC turns this into a startup I'll be impressed.

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