[reliablereason]

I did some basic calculations to compare the energy in the radiation vs the energy required to grow 10% extra.

- If we assume they are working in the reactor we get radiation levels of something like 1 mGy/hour. But we can prop this up to mabye 500 mGy/hour since i dont know how they grew their culture

- That leads to 0.05 J of extra energy per gram of microbial bio material.

- Energy needed to grow 1g of microbial biomaterial ≈ 3.15 kJ 10% of that is 315 J per gram

The result is that:

The amount of radiation energy available is 4 orders of magnitude too small to power even a 10% growth boost.

Edit: updated with more accurate estimations.

[once_inc]

Add in some evolutionary strategies, and you have the recipe for a good sci-fi book: a fungus in Chernobyl rapidly outpaces its competitors due to its ability to absorb radiation. Each iteration grows and reproduces faster, until it is so blindingingly fast that it begins to outpace the output the fuel rods produce.

The world rejoices as this fungus is perfect for cleaning up nuclear waste products, until we realize that it evolved to function outside of Chernobyl and begins to eat everything it can reach. Mankind launches into a desperate struggle for survival as the fungus lays waste to large swathes of land.

[gus_massa]

They don't eat the radioactive material and make it not radioactive.

[Assuming they use the radiation to get energy [1].] They just wait patiently until the radioactive atoms decay and emit radiation, like a gamma ray, and then absorb the gamma ray and use the energy. The half life of the radioactive material does not change.

[1] I still doubt this claim, but let's go along assuming the best case.

[Joel_Mckay]

Some fungi are already the largest organisms on earth at >200 km^2

Armillaria ostoyae ( https://en.wikipedia.org/wiki/Armillaria_ostoyae )

Consider when organisms must pass, that these ancient fungi likely still consume the host... Thus, on a 8000 year timescale most fungi doesn't necessarily need to pursue food that naturally dies in around a century.

Yeasts are already sharing your body along with numerous other organisms that are often harmless or even beneficial. Best not think about it too much if you are uncomfortable with seeing yourself as a mini ecosystem. =3

[wartywhoa23]

A variation on the Gray Goo scenario.

https://en.wikipedia.org/wiki/Gray_goo

[Andrex]

This lines up with a book idea I've had for like 20 years. Crazy!

Don't wait to write sci-fi I suppose! Life may catch up, haha.

[throwawaymaths]

Aside from the Chernobyl part, that's basically Andromeda strain

[khuey]

Some similar concepts are found in The Expanse for those who have not read/seen it.

[xattt]

Its only regret… not developing resistance to polyene antifungals.

[actionfromafar]

This is basically what happened. Then they became us.

[kalaksi]

I'm not sure where you're going with this, but since they have actually researched how it grows, I think it's more likely your calculations/assumptions are incomplete.

For example:

> Energy needed to grow 1g of microbial biomaterial

based on what?

Edit: Maybe you meant that radiation alone wouldn't be enough for that growth, so there'd be other components that it's helping with.

[reliablereason]

Initially i asked a AI for standard values but here is a proper source:

- Negentropy concept revisited: Standard thermodynamic properties of 16 bacteria, fungi and algae species ( https://arxiv.org/abs/1901.00494)

> Maybe you meant that radiation alone wouldn't be enough for that growth, so there'd be other components that it's helping with.

Yes. Clearly it grew as it grew, but the question is what drove/powered the growth.

[engine_y]

There's another parameter worth considering - how efficient is it to convert sunlight vs. gamma radiation into biologically usable energy.

What if for some reason gamma radiation changes the equilibrium constants for ADP --> ATP?

[aeonik]

Another hypothesis to test would be if the radiation is being used as a catalyst somehow.

E.g. Could be denaturing something else, unlocking a previously inaccessible energy source. Possibly some radiochemistry creating a new food source for the fungus too.

[credit_guy]

I also did some back of the envelope calculations. Here's what I got: the radiation level just 1 meter away from the "elephant foot" (the solidified molten core), at the time of the accident was about 1000 times lower than the solar irradiation. At 100 meters it was 10 million times lower (because of the inverse square law). Now, the radiation from the elephant foot has decreased significantly. I couldn't find a recent estimate, but I would expect it to be at least 100 times lower. So at 100 meters from the elephant foot, the radiation level is a billion times lower than what you get from the sun. There's no way any organism can "feed" on that.

[Retric]

> Here's what I got: the radiation level just 1 meter away from the "elephant foot" (the solidified molten core), at the time of the accident was about 1000 times lower than the solar irradiation. At 100 meters it was 10 million times lower (because of the inverse square law).

No, the elephants foot isn’t a point source at its surface.

To use an extreme example going from 1m away from the sun to 100m away from the sun doesn’t result in a 10,000x drop off in energy density. Instead the exponential drop-off occurs relative to the center of the sun because energy is coming from any point on the surface visible to that location. A similar principle applies with the elephants foot, though the geometry is more complicated.

[Retric]

> That leads to 0.05 J of extra energy per gram of microbial bio material

Over what timeframe? If that’s 0.05 J per hour and “the researchers found that fungi that faced the galactic cosmic radiation for 26 days grew an average 1.21 times faster” 26 * 25 / 21% and the numbers don’t look that unreasonable.

[reliablereason]

I calculated over 5 days. Which was just a guess.

But i focused on the 10% mentioned.

That said time could be factored out if you did everything properly.

[vintermann]

Yeah, from that it sounds like the main advantage of this mold is that it gets some compensation from all that deadly radiation, and thus does better than mold which doesn't.

[zamalek]

Right, it could be a lack of competition in the direction of the reactor. It's a giant petri dish for anything able to withstand radiation.

[PatronBernard]

Sources dude...