Scientists Create Living Concrete | Hacker News Reader

Scientists Create Living Concrete

nytimes.com

77 pointsprostoalex28 comments

The title insists on the "living" part but the really exciting one is the "photosynthetic" part!!

It is really revolutionary, as it is a "concrete" that solidifies without rejecting CO2, thanks to its cyanobacterial base.

A few years ago, I had the pleasure of visiting a NASA lab building "bricks" of fungi that could be used to build structures on Mars. It's very cool to see similar technology spreading on Earth - another example of how space exploration tech can mesh with the real world.

The paper Biomineralization and Successive Regeneration of Engineered Living Building Materials [1]:

> Living building materials (LBMs) were engineered that are capable of both biological and structural functions. LBMs were created by inoculating an inert structural sand-hydrogel scaffold with Synechococcus sp. PCC 7002, a photosynthetic cyanobacterium.

[1] https://www.cell.com/matter/fulltext/S2590-2385(19)30391-1

The idea of buildings having cancer is pretty awesome in its own terms.

Living concrete might help in environments harsher than even the driest deserts: other planets, like Mars.

“There’s no way we’re going to carry building materials to space,” Dr. Srubar said. “We’ll bring biology with us.”

The other day me and my friend were riffing on ideas regarding a game about a space courier.

One issue was: given how expensive interstellar travel should be, what could possibly be so valuable as to justify the operation?

Biology. It's possible that flinging hundreds of thousands vials (so as to have a good chance of catching at least one) with certain bacteria at relativistic speeds would be less expensive than coming up with a process of synthesizing the same features in a local species.

But biology is also information...

Did you come up with a good reason for technology advanced enough to support interstellar travel but not being able to replicate lifeforms synthetically from a digital copy? Maybe alien lifeforms where the detailed chemistry hasn't been worked out?

Materials that regenerate! It could be used in pavements. It would be useful in sidewalks. But I would not dare use this for anything especially structural like beams or walls. However, it could be good facade.

I'm thinking of the rock faces in "return to oz" and can't decide whether this is awesome, terrifying or both

Sounds good, but gelatin is made from animals, and raising animals is bad for the environment.

Cement accounts for 8% of global C02 emissions. The article says it would be a step forward environmentally, and I'm inclined to believe them.

Parent comment has a point. If this production type replaces cement completely, then we'd need to know the delta in carbon emissions of the increased production of gelatin compared to the reduction of carbon emissions in cement to make a logical comparison.

You might be absolutely right that gelatin is "cheaper" than cement, but because prices don't incorporate externalities (carbon included) we can't use them for comparisons of this type.

That's a fair point. However, stating the case for my argument, gelatin is a by-product and not necessarily a by-product of beef which is well-known for being a big contributor of C02 emissions, but other sources like chicken. From my understanding, anything that provides collagen can provide a basis for gelatin. To reach a well thought out conclusion dictates a full analysis, my gut feel is just that gelatin could provide a more environmentally beneficial solution.

Chicken produces health emergencies like bird flu.

Bird flu doesn't seem like an important environmental consequence which is what you two are discussing.

Not strictly environmental, no, but an economic externality nonetheless. I agree it's a stretch to use it in an argument about CO2 emissions, though.

The collective biological health of various species seems like an environmental concern to me. Economic externalities are a funny concept. Economists seem to use this term to obfuscate when their model fails to account for something unforeseen. In this case, various novel diseases seemed improbable. Until they weren't.

The way I see it, the concept of externalities is a way of systematically dismissing things as "relatively unimportant." The model is perfect, and describes a productive system beautifully, and anything unexpected that results from it is an "externality." Almost like a bug becoming a "feature" to someone who is unwilling to address the problems of a system they've constructed.

But that's what you get when your entire economy is based off of endless growth and profited market relations. I'm not an advocate of central planning for replacing markets, but definitely an advocate for production being about meeting needs instead of generating surplus value for private owners.

I agree with you about biological health being an environmental concern, by the way. But I'm willing to bet you and me might see things a bit differently from the regular crowd here. When most people think of the environment, they think of oceans, trees, rivers, air, etc.

Raising animals is not bad for the environment. There are ways of raising animals which absolutely helps regenerate the soil and which helps the environment. Please read up on regenerative agriculture.

I don't think anybody misunderstands this point but the question, as with many when talking about 8B people, is more about scale. Are there "ways of raising animals which absolutely helps regenerate the soil and which helps the environment" such that our current collective meat consumption can be fulfilled?

The primary idea behind regenerative agriculture is that manure helps soil. But plants regenerate soil too. Legumes for example fix nitrogen in the soil.

I think that it's a bit of a shame that you are being downvoted, since the point that (I think) you are making is valid.

Namely you need to look at the total cost of manufacture, especially with respect to the environment and/or CO₂ impacts.

This process, excluding inputs, has a lower CO₂ impact than traditional concrete. It also, currently at least, produces a less useful concrete, as it isn't as strong.

The question is what is the net environmental and CO₂ impact when you also include the inputs.

One area where this new process has a positive impact: * No need for virgin river sand, although it is unclear if desert sand could be used. At least this would be a good way to "recycle" concrete, which is notoriously hard to re-use.

One area where it has a negative impact: * This concrete is no longer vegan friendly. Although to be fair, many plantation woods are not strictly vegan either, since may plantations directly lead to a lowering of biodiversity and/or loss of animal habitat. Sand mining is also typically not "victimless". * Requires a more diverse input/supply chain. Although the article doesn't really go into the impacts of this, so it's hard to estimate how bad this is. For example, do we need a kg of gelatine per kg of concrete, or per tonne of concrete?

Links to why it would be useful to use Desert sand in concrete: Desert sand is not really usable for most things that we want sand for, for example, it is not suitable for concrete, since it is too fine. (https://petroleumservicecompany.com/blog/could-desert-sand-b...)

This is why, desire being in a desert, Dubai imports its sand! (https://www.bbc.com/worklife/article/20160502-even-desert-ci...)

I am being downvoted because I tried to make the point as succinctly as I could. It turns out, stating something with childish simplicity doesn't sound smart. I am also being downvoted because as other comments have noted, their intuition states that the solution could have a margin positive net impact versus the externalities associated with industrial concrete production. And according to the doctrine of technology solutionism, which is the doctrine of most people who read HN (myself included sometimes), the onus is frequently on the skeptic to show through rational analysis that the innovative solution has greater harm than benefit, while the believers in the innovative solution are allowed to suspend doubt and use their intuitive judgement to rationalize the relative efficacy of the solution at hand. It's like the technologists' version of Bertrand Russell's Teapot.

There is a difference between a succinct argument and an incomplete argument. I'll leave it there because you seem like you want a reason to be offended.

Should vegans eat vegetables grown in manure?

There are farmers experimenting with “vegan vegetables”: vegetables grown without manure, but plant-based fertilizer only. E.g. https://www.partyfortheanimals.com/inspiring-pig-farmer-beco...

Fascinating. This is an input that I hadn't considered.

However "Vegan" things is definitely a tricky subject… for example cars often have leather seats and/or steering wheels. And it can be quite hard to get a "decent trim" car, and _not_ get leather. Tesla do offer "non-animal-leather" seats, but not all manufacturers have such an option.

Companies like Geltor[1] are solving this problem. I'd be excited to see their processes more widely adopted.

[1] https://geltor.com/about-us/

the end game of alt.pave.the.earth is nigh!

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