Even more surprising: the droplets didn’t evaporate quickly, as thermodynamics would predict.
“According to the curvature and size of the droplets, they should have been evaporating,” says Patel. “But they were not; they remained stable for extended periods.”
With a material that could potentially defy the laws of physics on their hands, Lee and Patel sent their design off to a collaborator to see if their results were replicable.
I really don’t like the repeated use of the phrase “defy the laws of physics.” That’s an extraordinary claim, and it needs extraordinary proof, and the researchers already propose a mechanism by which the droplets remained stable under existing physical laws, namely that they were getting replenished from the nanopores inside the material as fast as evaporation was pulling water out of the droplets.
I recognize the researchers themselves aren’t using the phrase, it’s the Penn press release organization trying to further drum up interest in the research. But it’s a bad framing. You can make it sound interesting without resorting to clickbait techniques like “did our awesome engineers just break the laws of physics??” Hell, the research is interesting enough on its own; passive water collection from the air is revolutionary! No need for editorializing!
Yeah, science communicators need to not evaluate themselves by the same metrics as newspapers and magazines. Getting people to click and share should not be the metric of success.
It also somewhat instils distrust in science IMO, goes along the “eggs were bad for our health just 10y ago” type of argument
Those Egg Council creeps got to you too, eh?
Yeah, why pretend physics are being broken when we could instead discuss the fact that we’re one step closer to having moisture farming as a profession!
Cool, just have to go to Tosche Station to pick up some power converters first.
You can waste time with your friends when your chores are done.
Recently I found a new class of passive water aggregators in my snack. I call it ,“DO NOT EAT, SILICA”
pull water from the air, collect it in pores and release it onto surfaces without the need for any external energy
If this is legit, it’s going to be revolutionary.
If a “passive dehumidifier” is possible using this and a funnel/hose, that could be extremely exciting for basement and cellar owners everywhere
depends how space efficient it is. maybe you would you need to fill your entire basement with the stuff for it to work.
A surface-area maximizing structure like a radiator grille could probably be used if it’s anywhere near reasonable, but yeah, that could be a concern
That seems like it would violate the law of entropy by turning a high entropy state (water vapor mixed into the air) into a lower entropy state (water in liquid form), but I’m probably just missing something.
I don’t at all understand why the second law of thermodynamics is being invoked. Nonetheless, capillary condensation is already a well-studied phenomenon. As the scientific article itself notes, the innovation here over traditional capillary condensation would be the ability to easily remove the water once it’s condensed.
Re: Entropy:
- Entropy is a statistical phenomenon that tends to increase over time averaged across the entire body, i.e. the Universe. Not literally every part of the Universe needs to increase its entropy as long as on average it is increasing. You’re evidence of that: your body is a machine that takes entropy and pushes it somewhere else.
- Water vapor is a high-energy state compared to liquid water. What you’re saying therefore is the opposite of how the second law works: water vapor’s energy tends to spread out over time until it eventually cools back to a liquid. Liquid water is a higher entropy state than water vapor.
The entropy of a little water mixed with air is higher. As with anything that mixes a little.
Condensation is exothermic, though, so the material will heat up slightly
Yeah that was my thought too. I hope it makes it to actual use cases and not just lab proof of concept.
Yeah now we can industrially extract all the remaining water from the air as well as the ground.
edit: Sorry I thought it was obvious this was slightly tongue-in-cheek.
You realize the amount of water is constant, right?
Not if Nestle has anything to say about it
They do have a point about groundwater though.
We prefer the term “recycled dinosaur pee”.
FMT99 missed the week they taught the water cycle.
Water is created and destroyed by biological and other natural processes. Here go photosynthesis:
6CO₂ + 6H₂O + Light → C₆H₁₂O₆ + 6O₂
I am fairly certain they are referring to the fact that we are already removing water from the fresh water cycle, and this could remove even more. For example, global warming combined with draining the aquafers means less water in the cycle as it was drained into the ocean and isn’t beaing replenished as snow/glaicers.
Yes, the total volume of water on the planet isn’t being changed by that shift, but the amount of freshwater is.
Nobody will remove water from ambient air in relevant amounts. Roughly 0.5 % of air is water vapor, a total of something like 10’000 km³ liquid water. This is replaced (residence time) about once every 10 days, so roughly 1’000 km³ daily.
Say we extract 10 km³ (10’000’000 m³) daily, enough for roughly 10 million people (including all industry, zero recycling of the water etc.). By that time you deal with 1 % of earths atmosphere every day. May I remind everyone how absurdly costly in any conceivable way that would be? You would rather lay a few pipes and purify sea water at a tiny(!) fraction of the cost.
They won’t drain the aquifers, nature will replace that much water!
They won’t cut down all the forests, the trees will just regrow!
They don’t have to cycle the entire atmosphere to cause havoc. Pulling the moisture out in local areas that already have lost aquifers and ice in the mountains is the obvious issue. Plus, you don’t know the cost in the long run, it could end up being fairly cheap.
People were able to (and at some places did) cut down every tree WELL before they had power tools and even saws. Just with axes. The comparison is laughable.
No, massive air moving structures can not be cheap. Neither building nor operating them.
Stillsuits incoming.
I have a long distance call from Arakis, the Fremen are on line 1…
Please, the stretchy part of my sweatshirt sleeves have done this for years.
I’d recommend reading the article before trying to make a comparison.
When water condenses on surfaces, it usually requires either a drop in temperature or very high humidity levels. Conventional water harvesting methods rely on these principles, often requiring energy input to chill surfaces or a dense fog to form to collect water passively from humid environments. But Lee and Patel’s system works differently.
Isorhermal (unpowered) water condensation from capillary action isn’t the interesting part, (and the article title doesn’t really make that clear), but the potential ease of water extraction after condensation is interesting - and the original paper makes it clear in the discussion that that part isn’t done yet and isn’t guaranteed
So, trees with more steps?
Trees harvest it from the ground, not the air.
Trees absorb MOST of their water through the soil, but are absolutely capable of absorbing water directly into their leaves. Google “Foliar uptake”
