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].
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.
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...
> Maybe the mass of the fungus can be grown from CO2 from respiration.
That's not a thing. Fixing carbon to a usable form [0] using "general biological energy source" to the carbon pool is extremely difficult (there are only four and a half, counting c3 vs c4 as a half, pathways known) and requires complex machinery to achieve.
[0] assimilating carbon dioxide in general is not difficult, even humans do it but it does not enter the general carbon pool and is effectively only transiently converted out of CO2, and net does not contribute to biomass.
Either you ship steel, or you ship biological material - you're shipping things either way. (And if you can do ISRU, then steel or just plain cast iron is available)
>> it could be shown that the melanized fungus C. sphaerospermum can be cultivated in LEO (Low Earth Orbit), while subject to the unique microgravity and radiation environment of the ISS.
I believe this "small scale" experiment was meant as a "proof of concept" to illustrate the idea whether this could be done in house in adverse conditions (unlike Earth's conditions) and could be a potential long term solution for radiation attenuation. I would hope that these somewhat promising results would allow them to conduct a large scale experiment.
Well technically it already is pretty darn green in that the energy system concentrates its waste into tiny generally well-contained packages that have, per TWh generated, a relatively miniscule negative impact and footprint on the biosphere.
I recognize this is controversial but the numbers are pretty solid.
Adam Stone has basically discovered that the radiation that causes the Great Pain of Space not only affects life, it is absorbed by it. So, surrounding yourself with other living creatures will prevent you from feeling the pain yourself. He eventually settles on building a shield out of live oysters, since they lack any central nervous system to experience pain with.
Interesting - how haven’t I heard about that story? I immediately thought about how Rick covers his outpost in screaming Mortys so that the galactic government can’t detect him. Morty pain as anti-Rick is a strange, appealing and disturbing thought... they’re effectively oysters soaking up the pain of the universe.
There's simply no way that this type of fungus could absorb enough radiation simply because it's not dense enough.
If you want to absorb radiation you have to block it which means it has to come into contact with matter.
The only way you can do this is to have either a smaller volumetric amount of something that's dense (lead, gold, uranium, etc) or a LARGE amount of something less dense (water, concrete, etc).
If you're just talking about an organic organism, sure, it can use the radiation BUT you'd need to have a MASSIVE amount of it in terms of volume and weight.
Simply put, the fungus itself is sparse when looking at it from a subatomic perspective. Most of the radiation passes right through it.
I think the whole framing of this discussion is inappropriate. The interesting thing about this fungus is that it can use the radiation as an energy source to sustain life. The fact that we can’t use the fungus as some kind of miracle lightweight radiation shield is missing the point.
Here we have a life form that has adapted to make use of a very unusual (on earth’s surface, anyway) energy source. That should not be taken for granted. It’s an amazing demonstration of the adaptability of life. It also warrants a deeper investigation into how this ability works and how it came about by evolutionary processes.
Agreed, lead blocks radiation quite well. I don't know why anyone would care about that property in a fungus. What is fascinating is that life evolved a novel energy pathway here, this is like photosynthesis but with gamma radiation. I'd love to know more about it.
> I don't know why anyone would care about that property in a fungus.
My thought would be the possibility of it being cheaper to produce than lead, possible to farm it. That could mean a more lightweight material for insulated suits and stuff along those lines.
> It's unlikely to be much use for shielding for reasons the top comment explains.
I did read the comment - I know it can't be used for that.
I only said that as a more generic response to "I don't know why anyone would care" about this property being found in a fungus - a statement which seemed to lack any imagination imo.
> The real reason to care is because it's an interesting - almost textbook - example of evolution operating in a challenging environment.
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.
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.
>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.
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.
Density blocks radiation but it's the "hard way" of doing it
It's better to have something that resonates in the frequencies you want to block.
Given that melanin already works in the UV range it's not surprising that maybe with some changes it works with higher frequencies (though not too trivial neither because of the way quantum physics work)
I work in ionizing radiation transport. We use materials with high electron densities to shield gamma rays. Should we be using a material that "resonates" with gamma rays instead? If so could you provide an example of this working on gamma rays?
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?
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 lead because they have lots of electrons to stop gamma rays.
No where on this list of tools have I ever seen "materials that resonate with the radiation" so I'm just asking what the heck kind of radiation shielding physical effect is being referred to.
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.
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?
What’s astonishing is not the ability to block radiation (after all, biology will always defer to chemistry first, and physics second—there’s no way biology can come up with something that exceeds the capabilities of its substrates) but rather life’s way of rapidly adapting to make use of whichever energy source it can find to eke out an energy budget to thrive on.
P.S. Who else heard Dr Ian Malcom say “Life... finds a way” in their head?
On the contrary, I’d argue that most “life” (in the sense of our Eucledian definition of it) relies on exceeding the capabilities of its substrates via emergent properties - at least from the perspective of our current infantile understanding of the universe. Photosynthesis is so efficient because electrons jump multi-molecule gaps due to quantum effects, as we’ve found only a few years ago. The theory that most biological brains heavily leverage quantum processes is rapidly gaining ground as well - we simply lack the intelligence and processing capacity to design anything like it, since compared to our current computational abilities, millions of years worth of entropy may as well be an infinite amount.
Reductionism fails as completely as it does hilariously when it comes to systems where the whole does indeed exceed the sum of its parts due to laws of the universe we have yet to grasp. A much more sane approach is to think of the matter something is comprised of as nothing more than a filter/transformer for the entropy and environment it exists within. Life routinely harnesses entropy whereas our current technology is so ass backwards it does little but struggle against it (dendrites in batteries, for example). What science considers to be degradation or wear and tear is the very process living things rely on to exist - let that sink in.
I think you’ve missed my point entirely: the jumping of electrons that makes photosynthesis “so efficient” (which it isn’t—as a recent post here mentioned, it’s tuned for stability) is not in defiance of the laws of physics, but entirely compatible with them.
Only density can attenuate nuclear radiation, that’s the fundamental physical intuition here (which is also absent from the article/video posted). Nothing “merely biological” is going to change that. Now, making use of some of the energy that is attenuated by the non-dense biological medium... thta’s entirely within the biological domain.
> That’s true, but only local and short lived and very local effect.
And critically for my argument, photosynthesis works (less efficiently) even when this effect is absent. It’s not a mystery ingredient that makes the whole thing work.
Life can't exceed the capabilities of its substrates on their own terms, but it's not clear that life can be fully explained in or reduced to those terms either.
I’m glad you made this point, because it allows me to issue a cautionary word to those dualists who think that somehow the mind is something disjoint from the brain.
Yes, I'm glad you mention that; unfortunately I think sometimes the idea that causation may be multi-dimensional (in other words, that there is not necessarily a single implicative model capable of wholly explaining all things) gets mistaken for some sort of dualism.
But that view does not imply that mind and body are disjoint, are separate "essences", etc.
>> radiation beneath a ≈ 1.7 mm thick lawn of the melanized radiotrophic fungus (180° protection radius) was 2.17±0.35% lower as compared to the negative control.
2% doesn't seem much but again its just from 1.7 mm thick fungus. Wouldn't it be easier to grow it on Earth instead and test with thicker fungus layer for a significant attenuation of the radiation? I understand that they want to use it eventually on the ISS but couldn't the prototype be tested on Earth as well?
No, but the existence of water on Ceres was retconned in the show, now it’s again not accurate since while we discovered it has water between the book and the show we didn’t knew that it had that much water.
Yep but in the show in the first episode it was “fixed” the protestor says that Ceres used to have plenty of water until the inners stripped it for themselves.
> 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 mechanism in a non-organic setting?
This is pretty much one the hardest things to do in science today, replicating complex biological processes in a non-biological manner.
Insulin while being the first human protein to be synthesized today is still created using biotechnology by using bacteria to manufacture it simply because of how difficult it is to synthesize proteins.
>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 acid was originally produced on an industrial scale from fruit, circa WWI, due to shortages, Pfizer started making it using microbes, specifically black mold.
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.
Creating the same molecules would be considerably more complex than harvesting them heck we might not even be able to make them at all there is a plethora of compounds we use on a daily basis we can’t synthesize.
Your example isn’t a particularly good one solar panels and photosynthesis don’t operate in the same manner, if we needed to produce chlorophyll at scale we probably wouldn’t be able too.
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.
Well, we are as much alike as our consciousness/brain can manage to find a pattern for. The consciousness compresses reality by finding patterns. As long as we are able to understand some phenomenon, there will always be a pattern that this understanding is serviced by, and we will be able to see some relation between two different things through that pattern. In that sense, everything we perceive will be connected in one way or another. In that sense, everything is "one".
But does that say anything about the physical world, or rather about our own brains, our consciousness and how it works? A matter of perspective. And of how you define "real".
Fungi and animals actually have a common ancestor, protista. It's not exactly my area of expertise, but I believe that the way a fungus grows its tendrils and communicates over it is much like our nervous system.
Here[0] is a fancy graphic that succinctly displays how the kingdoms of life are categorized.
Protista is a paraphyletic group of single-celled eukariotes. However, animals and fungi are each other's closest multi-cellular living relatives. Animals are closer to other holozoa, and fungi are closer to other holomycota, but both are equally distant from, for example, Amoebozoa, which includes many other protists.
I attended a course of neurophysiology, and the most stunning thing I've found was that all (or maybe almost all, I don't remember clearly) the neurotransmitters used by a human's neurons exist in a single cellular organisms, even in prokaryotes. Serotonin, glutamat, dopamin and others could be found in bacteria, so bacteria had all the chemistry needed for a central neural system hundreds of millions years ago, and nevertheless it took hunderds of millions years ago to build Einstein's brains.
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.
It shouldn't be too surprising since the universe and earth have been and remain naturally filled with radiation for billions of years. The heat that keeps magma warm in the earth comes 50% from radioactive decay of uranium and its daughters. Life today is based on plants and microorganisms absorbing radiation emanating from a giant nuclear reactor in the sky.
This is just a twist on how it's always been done.
Last minute changes to the content become a bit of a nuisance when the deliverable involves a voice recording, to say the least. A good synthesis pipeline could be set up to re-render the whole thing on a git hook.
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This happened in a demo at work recently. I couldn't follow along, the robot voice was just too distracting.
In that case I think it was someone insecure in their English skills, which I guess I can understand. I would rather they just do their best and we will make it work. Most of my coworkers are ESL anyway.
If it's really a problem just ask someone else to do the voiceover. The robots are not anywhere close to good enough to do the narration without being incredibly distracting.
>In that case I think it was someone insecure in their English skills, which I guess I can understand. I would rather they just do their best and we will make it work. Most of my coworkers are ESL anyway.
I think at this point, I can discern even the thickest of accents if the person were to talk slow because of my (awesome) ESL coworkers, but I'm not sure the average person from my city would be able to do the same with some thick ESL accents. I'd personally prefer the human voice like you, though.
I think this speaks to a common fear of technology taking over and incidentally/consequentially killing everyone. Like the Terminator series, and many others as well. IRL you might recall the torrents of fearful articles and posts about the world being consumed by a human-triggered black hole when they started building the massive colliders. And every few years, someone predicts AI will do us in. And HAARP killing us with bad weather and earthquakes. So many examples abound.
[1] https://www.biorxiv.org/content/10.1101/2020.07.16.205534v1....
[2] https://apps.dtic.mil/dtic/tr/fulltext/u2/a278139.pdf
Edit: I made a mistake in this comment, see child comment for correction.