Fungus at Chernobyl absorbs nuclear radiation via radiosynthesis • Hacker News Board

Re: Fungus at Chernobyl absorbs nuclear radiation via radiosynthesis

#81

Post by raverbashing » Sat, Aug 15, 2020, 4:51 PM UTC

acidburnNSA wrote: post #79

ckdarby wrote: post #74

Earlier quoted context omitted.

I down voted your comment, here is why. Working in transporting this material I'd gather you'd have expertise related to this. Could you better explain why the existing approach is used?Can you counter the arguments made by what you're replying on? Is your comment providing value or information to who you're replying to?

Thank you for explaining! Gamma rays interact with atomic electrons and get slowed down via the photoelectric effect, compton scattering, and pair production [1]. Depending on the energy of the gamma ray, different fractions of those interactions will dominate. The ones that matter most for most ionizing gamma rays we encounter work better if there are more electrons packed in. So we use high density materials like l…

You are right of course, but the effects you're describing are kind of what I meant

Yes, I don't think there is a magic material that will perfectly resonate with high energy gamma rays. But evolution might be able to figure it out. Maybe "resonance" is more specific, and "interaction" is better.

My criticism was more to the " you need thick material to stop radiation" whereas the answer is more "we need thick material because that's the best material we know for the job". Glass is opaque to UV which is more energetic than visible light for example.

And not to forget we know if some materials that do absorb gamma rays, the issue is that they like to go boom after doing that https://en.m.wikipedia.org/wiki/Photofission

Re: Fungus at Chernobyl absorbs nuclear radiation via radiosynthesis

#82

Post by Hnrobert42 » Sat, Aug 15, 2020, 4:53 PM UTC

barbegal wrote: post #40

barbegal wrote: post #31

I am skeptical that this fungus absorbs radiation significantly more than the equivalent amount of water would. The paper [1] isn't very clear about possible inaccuracies in the results and I don't understand why this experiment hasn't been repeated down on Earth. The mass attenuation coefficient of the fungus is 0.234 cm^2/g at 100MeV whereas water is 0.0166 cm^2/g according to this paper [2]. [1] https://www.biorxi…

Reading the paper again, I made a mistake in my comment above. The mass attenuation coefficient was at 10keV not 100MeV. Water has a mass attenuation coefficient of about 5cm^2/g at 10keV. Table 1 [1] in the paper shows the true comparison with water at 100 MeV where it can be seen that there is not a large difference. On a weight basis stainless steel outperforms the fungus. [1] https://www.biorxiv.org/content/10.11…

Maybe it’s because you have to ship stainless steel from Earth. Maybe the mass of the fungus can be grown from CO2 from respiration. The carbon originally coming from food, which has to be shipped up. Lots of maybes, but you know, maybe...

Re: Fungus at Chernobyl absorbs nuclear radiation via radiosynthesis

#83

Post by rch » Sat, Aug 15, 2020, 5:03 PM UTC

barbegal wrote: post #40

barbegal wrote: post #31

I am skeptical that this fungus absorbs radiation significantly more than the equivalent amount of water would. The paper [1] isn't very clear about possible inaccuracies in the results and I don't understand why this experiment hasn't been repeated down on Earth. The mass attenuation coefficient of the fungus is 0.234 cm^2/g at 100MeV whereas water is 0.0166 cm^2/g according to this paper [2]. [1] https://www.biorxi…

Reading the paper again, I made a mistake in my comment above. The mass attenuation coefficient was at 10keV not 100MeV. Water has a mass attenuation coefficient of about 5cm^2/g at 10keV. Table 1 [1] in the paper shows the true comparison with water at 100 MeV where it can be seen that there is not a large difference. On a weight basis stainless steel outperforms the fungus. [1] https://www.biorxiv.org/content/10.11…

I wonder if material degradation factors like neutron embrittlement would tip the scales in favor of a fungal barrier at longer timescales.

Re: Fungus at Chernobyl absorbs nuclear radiation via radiosynthesis

#84

Post by acidburnNSA » Sat, Aug 15, 2020, 5:12 PM UTC

raverbashing wrote: post #81

acidburnNSA wrote: post #79

Earlier quoted context omitted.

Thank you for explaining! Gamma rays interact with atomic electrons and get slowed down via the photoelectric effect, compton scattering, and pair production [1]. Depending on the energy of the gamma ray, different fractions of those interactions will dominate. The ones that matter most for most ionizing gamma rays we encounter work better if there are more electrons packed in. So we use high density materials like l…

You are right of course, but the effects you're describing are kind of what I meant Yes, I don't think there is a magic material that will perfectly resonate with high energy gamma rays. But evolution might be able to figure it out. Maybe "resonance" is more specific, and "interaction" is better. My criticism was more to the " you need thick material to stop radiation" whereas the answer is more "we need thick materi…

Just quick response on the last point: Photofission reactions happen all the time in places like nuclear reactors. There are no materials that I'm aware of that photofission explosively. The photofission reactions are generally very rare compared to all the other reactions. Heck, natural uranium in your kitchen counter spontaneously fissions all the time but that doesn't lead to an explosion because 1 million atoms is a lot less than 1e23 atoms. Am I missing something?

Re: Fungus at Chernobyl absorbs nuclear radiation via radiosynthesis

#85

Post by 08-15 » Sat, Aug 15, 2020, 5:16 PM UTC

acidburnNSA wrote: post #67

jojobas wrote: post #54

Earlier quoted context omitted.

Absorbtion is a misnomer. It uses a tiny fraction of energy of whatever particle it is. In terms of attenuation it cant be different from anything else of similar density and composition.

But then why this seemingly-ridiculous line from the article? > Scientists are thinking of shielding astronauts and space objects with a layer of this radiation-absorbing protective fungus.

Because NASA is no longer relevant, but desperately wants to be. So they publish anything, and anlways with a sensational headline: microbes that incorporate arsenic into biomolecules, reactionless microwave propulsion, and not fungal radiation shields.

That line doesn't just seem ridiculous, it is.

Re: Fungus at Chernobyl absorbs nuclear radiation via radiosynthesis

#86

Post by dogma1138 » Sat, Aug 15, 2020, 5:17 PM UTC

perl4ever wrote: post #76

dogma1138 wrote: post #8

Earlier quoted context omitted.

> Is it doable to maintain a 21-cm thick layer of fungus, at all, let alone in space, for a prolonged period of time? Building a living wall isn’t hard, I have one with moss in my flat it does wonders for air quality (even if not actual one just the smell/perception is enough), fungus is easy to grow - feed it shit and keep it in the dark does work. > Wouldn't it be easier/simpler to replicate this radio-synthesis me…

>Insulin while being the first human protein to be synthesized today is still created using biotechnology by using bacteria to manufacture it An interesting factoid I ran across is where citric acid comes from. I had noticed inexpensive "lemon iced tea" had citric acid listed as an ingredient, and vaguely thought perhaps it's called that just because the citrus source is heavily processed. Turns out, while citric aci…

Citric acid is used as a preservative and regulator in food so it will be added even if the ingredients contain it naturally simply for consistency with flavored drinks it’s even more common to basically break everything down to their base chemical ingredients and then add them back in at the exact amounts.

Overall pretty much anything that is naturally produced in plants and animals will already be the most “efficient” way of doing that both due to natural selection and both due to the fact that the process is easily scalable, heck we still make rubber from the rubber tree because nothing else comes close to that.

Chemistry is fucking hard and we don’t have anything close to the molecular machinery that living organisms have to assemble complex molecules.

Chemistry in living things is like a robotic assembly line in a factory, chemistry in manufacturing is throw stuff into a reaction chamber and stir it until something happens.

Re: Fungus at Chernobyl absorbs nuclear radiation via radiosynthesis

#87

Post by xsmasher » Sat, Aug 15, 2020, 5:22 PM UTC

acidburnNSA wrote: post #67

jojobas wrote: post #54

Earlier quoted context omitted.

Absorbtion is a misnomer. It uses a tiny fraction of energy of whatever particle it is. In terms of attenuation it cant be different from anything else of similar density and composition.

But then why this seemingly-ridiculous line from the article? > Scientists are thinking of shielding astronauts and space objects with a layer of this radiation-absorbing protective fungus.

Because the "article" is a clickbait Youtube video from a channel with videos like "Is the world ending in 2020?" and "Ghost caught on tape in my apartment." It doesn't even name the scientists.

I went searching for "NASA Chernobyl fungus" and found a paper about using it as a shield on mars: https://www.biorxiv.org/content/10.1101/2020.07.16.205534v1

>Estimations based on linear attenuation coefficients indicated that a ~ 21 cm thick layer of this fungus could largely negate the annual dose-equivalent of the radiation environment on the surface of Mars, whereas only ~ 9 cm would be required with an equimolar mixture of melanin and Martian regolith.

It makes more sense in the Mars context, where you might not have lead available, and where growing a large amount of fungus from a small seed packet is a big bonus.

Re: Fungus at Chernobyl absorbs nuclear radiation via radiosynthesis

#88

Post by dogma1138 » Sat, Aug 15, 2020, 5:23 PM UTC

bobhel wrote: post #75

Tade0 wrote: post #59

Is the fungus edible?

Here's the real question. Or, can it be made edible? Cultivating something like this on Mars out in the open makes more sense than growing potatoes indoors.

Even if it’s not directly edible it can be a source of amino acids and proteins that could be then processed into something edible or be a source of food for other things that provide better nutritional value to humans like yeast.

The question is it going to be more cost effective than hydroponics.

Re: Fungus at Chernobyl absorbs nuclear radiation via radiosynthesis

#89

Post by lopmotr » Sat, Aug 15, 2020, 5:25 PM UTC

Hnrobert42 wrote: post #82

barbegal wrote: post #40

Earlier quoted context omitted.

Reading the paper again, I made a mistake in my comment above. The mass attenuation coefficient was at 10keV not 100MeV. Water has a mass attenuation coefficient of about 5cm^2/g at 10keV. Table 1 [1] in the paper shows the true comparison with water at 100 MeV where it can be seen that there is not a large difference. On a weight basis stainless steel outperforms the fungus. [1] https://www.biorxiv.org/content/10.11…

Maybe it’s because you have to ship stainless steel from Earth. Maybe the mass of the fungus can be grown from CO2 from respiration. The carbon originally coming from food, which has to be shipped up. Lots of maybes, but you know, maybe...

To grow fungus from CO2, don't you first have to grow a plant then let the fungus eat dead plant? Plants require (heavy) equipment to support them.

Re: Fungus at Chernobyl absorbs nuclear radiation via radiosynthesis

#90

Post by filoeleven » Sat, Aug 15, 2020, 5:36 PM UTC

einpoklum wrote: post #5

Ok, but: 1. Is it doable to maintain a 21-cm thick layer of fungus, at all, let alone in space, for a prolonged period of time? 2. Wouldn't it be easier/simpler to replicate this radio-synthesis mechanism in a non-organic setting?

On (2): It is often easier to have the organism do it for us.

Fungi are especially good at creating defense compounds like antivirals, antibacterials, and antifungals. This makes sense when you think about how they grow: miles of hyphae in a single square inch, and only one cell wall keeping the inside from the outside.

There are a lot of compounds that we don’t know how to synthesize, or where it’s so costly so as not to be worth it. Compare that to simply feeding a mushroom waste and waiting. Plants work similar wonders with chemistry.