Penn Engineers Discover a New Class of Materials That Passively Harvest Water from Air
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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!
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Please, the stretchy part of my sweatshirt sleeves have done this for years.
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You realize the amount of water is constant, right?
They do have a point about groundwater though.
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So, trees with more steps?
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I have a long distance call from Arakis, the Fremen are on line 1....
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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.
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You realize the amount of water is constant, right?
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.
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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.
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Stillsuits incoming.
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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.
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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!
It also somewhat instils distrust in science IMO, goes along the "eggs were bad for our health just 10y ago" type of argument
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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.
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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?
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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.
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You realize the amount of water is constant, right?
We prefer the term “recycled dinosaur pee”.
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Recently I found a new class of passive water aggregators in my snack. I call it ,"DO NOT EAT, SILICA"
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You realize the amount of water is constant, right?
Water is created and destroyed by biological and other natural processes. Here go photosynthesis:
6CO₂ + 6H₂O + Light → C₆H₁₂O₆ + 6O₂
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So, trees with more steps?
Trees harvest it from the ground, not the air.
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Those Egg Council creeps got to you too, eh?