I think you are misusing Berkson's Paradox here. It applies when you sample two extremes, i.e. when you look at the richest 0.1% and the most moral 0.1% and notice that the two appear mutually exclusive, even though they might actually be uncorrelated in the general population. When you look only at the richest 0.1% and notice their lack of morals compared to the general population, that is a legit correlation.
Elsewhere in the world (under IFRS accounting rules) capitalization of R&D costs has been a firm requirement for a while. The US has been somewhat unique in allowing them to be expensed instead, until recently.
Yeah, seems I was wrong about that. Apparently most IFRS countries allow expensing R&D for tax purposes, regardless of accounting. Many even have an R&D superdeduction nowadays.
If the business has some revenue, but is not yet profitable after deducting development costs, it can become profitable on paper (and owe tax) if R&D is capitalized instead.
That depends on what kind of aviation we are talking about. An air taxi usable over 200km with 2 passengers is easy to achieve. But a minimally useful regional plane with 100+ passenger capacity is an entirely different matter, because it will be subject to the same regulations as conventional airliners. That is operational margin, winds, diversion and hold, etc. This means you probably need something like 2000km net range to be able to fly 500-1000km routes, which means you need close to 1000 Wh/kg batteries under reasonable assumptions for battery mass fraction and L/D-ratio.
> Note: When I say “wheel” throughout this post, please replace it with whatever tool, protocol, service, technology, or other invention you’re personally interested in.
Keeping the temperature constant with a thermostat is not an issue here. That would only explain things if the surface were kept cooler than the surrounding air (below the dew point), but from the description in the paper that does not seem to be the case. They basically claim that macroscopic droplets form spontaneously from an unsaturated vapor. And no, this is not something permitted by the second law of thermodynamics.
> And no, this is not something permitted by the second law of thermodynamics.
If someone points out to you that your pet theory of the universe is in disagreement with Maxwell’s equations—then so much the worse for Maxwell’s equations. If it is found to be contradicted by observation—well these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.
While I generally agree that it sounds dubious, this argument depends on whether the entropy of the liquid in the pore is lower than the entropy of the vapor in the air in the pore. I could see a highly hydrophilic capillary restricting a vapor enough to where it has better entropy in a liquid state.
If that's true we just need to balance energy, which the cooler does.
> I could see a highly hydrophilic capillary restricting a vapor enough to where it has better entropy in a liquid state.
My other comment here (and and a reply to a similar question) has more detail [1], but in short: this is true for capillaries and pores, it is not true for "collectable" droplets on a flat surface.
Practically it just means that the energy to form the droplets is coming from somewhere else, just not via cooling the surface below the dew point. For instance, you could imagine something like squeezing a material that undergoes capillary condensation to get the water out, since you'd pay the requisite energy cost via mechanical work.
Unless they have buried some really important caveat somewhere in the paper [1], it really looks like they are making claims that are incompatible with the second law of thermodynamics. They claim that water droplets are condensing on their nanomaterial at constant temperature and less than 100% relative humidity. This is absolutely forbidden by thermodynamics as we understand it. Under these conditions droplets can condense within pores (forming a concave surface), but they can never form a convex droplet on a flat surface.
Their mumbo-jumbo about water being "squeezed out" onto the surface by the hydrophobic component is totally bogus as well. The condensation will just stop earlier, without overflowing. Water condensing in concave pores and being squeezed into convex droplets requires hydrostatic pressure to be positive and negative at the same time.
The possibilities I see are: 1) contaminated surfaces 2) miscalibrated relative humidity or 3) they've neglected to mention a cooling plate that keeps the material below ambient.
I'm not sure what's forbidden here. You don't need 100% relative humidity to grab water from the air in fact in any wood has a moisture content that in equilibrium is in relation to the air moisture content. The moisture diffuses into every material and evaporates based on where it finds less vapor pressure. That's why you may have dry lips at 40% RH versus moisturized lips at 70% RH.
What you're referring to is condensation and is caused by air oversaturation due to a temperature drop which doesn't seem to be the case here.
Theoretically speaking, you can have a material that somehow absorbs high moisture from the air but has microscale properties that promote creation of droplets then somehow these droplets are separated from the rest of the air (with something like a smart vapor retarder, a passive material) and the water gets harvested.
What you are referring to is called capillary condensation [1]. When you have a hydrophilic surface with thin capillaries or small pores, they can pull water from the air below 100% RH. However, this process requires an enclosed space with a very small radius and the air-water interface is always concave in this case (it's just how capillary forces work).
Forming a convex surface, on the other hand, requires an at least slightly hydrophobic material and produces a positive internal pressure. This is a key difference, because condensation into a hydrophilic pore is favorable in terms of free energy, while condensing onto a hydrophobic surface is unfavorable (unless you have a supersaturated vapor).
> Theoretically speaking, you can have a material that somehow absorbs high moisture from the air but has microscale properties that promote creation of droplets then somehow these droplets are separated from the rest of the air
That "somehow" is what makes the paper's claims impossible. The water condenses spontaneously into the pore because it thereby lowers its free energy. Extruding it onto the surface is then even more unfavorable than direct condensation. Unfortunately, no passive system can achieve this feat, no matter how cleverly nanostructured, as it would go against the arrow of increasing entropy. You need an external energy source to drive that process.
The reverse problem is also true with such materials:
Water harvesting in pristine lab conditions may break down rapidly in realistic scenarios. Something that’s wet attracts dust and microbes. Dust plus water means more microbes. You’ll have lichen growing on this stuff in no time.
Zeus would like to file an injunction against the impostors associating his name with a something-equivalent¹ something. The Zeus brand stands only for supreme dominance. Zeus would not object to an actual zettawatt laser being named after him.
> You'd get the same result if you asked a random student to fully translate a passage from Hamlet, sentence by sentence, with no prior context. Or asked a random CS student to explain a random snippet of source code from the Linux kernel line by line. Most people don't deeply understand most things unless they get the bug and decide to dig in for fun.
I would rate the amount of specific context necessary to understand a random snippet of kernel code much higher than what you need for that Dickens passage. It's certainly much more dense with metaphor and playful use of language than normal prose, but I don't find it that opaque, even as an non-native speaker.
> The point is that you can't force comprehension on someone who isn't interested or motivated on their own. Most students are just muddling through because they "have to get a degree".
Well, yes, but that doesn't necessarily contradict the article. The bell curve at the bottom basically says that the comprehension they were expecting is in the top 3% or so, not the 60% of the general population who "have to get a degree". Add in all the Netflix and TikTok casualties, and the result ceases to be surprising.
