ar813

That's wild! Now I want to go hunting for more such examples..

If I take a step back and think back to say a few (or 5) years ago, what LLMs can do is amazing. One has to acknowledge that (or at least, I do). But as a scientist it's been rather interesting to probe the jagged edge and unreliability, including using deep research tools, on any topic I know well.

If I read through the reports and summaries it generates, it seems at first glance correct - the jargon is used correctly, and physical phenomena referred to mostly accurately. But very quickly I realize that, even with the deep research features and citations, it's making a bunch of incorrect inferences that likely arise from certain concepts (words, really) co-occurring in documents but are actually physically not causally linked or otherwise fundamentally connected. In addition to some strange leading sentences and arguments made, this often ends up creating entirely inappropriate topic headings/ sections connecting things that really shouldn't be together.

One small example of course, but this type of error (usually multiple errors) shows up in both Gemini and OpenAI models, and even with some very specific prompts and multiple turns. And keeps happening for topics in the fields I work in in the physical sciences and engineering. I'm not sure one could RL hard enough to correct this sort of thing (and it is not likely worth the time and money), but perhaps my imagination is limited.

If they can do this to Harvard, what hope do other universities have?

Between NIH grant-making being slowed down and this, there is no way to interpret these moves than being an underhanded way of causing university research infrastructure to collapse. Consider also, for example, that one Friday last month there was an announcement that indirect rates being cut to 15% for Dept. of Energy grants.. but only for universities, not companies or national labs!

Just from a steady state picture there is now significantly less funding flowing to America's research institutions and institutes. At some point buildings will be shut down, infrastructure mothballed and a generation of scientists will simply not be trained.

An adversary could not ask for a better outcome.

The answer to this problem lies here: “Entsminger pointed out that roughly 80% of the river’s flow is used for agriculture, and most of that for thirsty crops like alfalfa, which is mainly grown for cattle, both in the U.S. and overseas.”

The simple solution would be to raise prices on water such that it disincentivizes growing water hungry crops than alfalfa for example. The west’s water crisis is less about cities than agricultural choices made during the last century, which was wetter than it will be going forward. The obvious answer is to either regulate or incentivize using less water hungry crops more strongly. It would be better if this had started slowly a while ago, allowing the market to adjust and reallocate. Alas, looks like it will have to be an abrupt shift in the near future.

Erdős apparently came up with the following poem to break the ice, which is pretty funny!

This is the city of Madras / The home of the curry and the dal Where Iyers speak only to Iyengars/ And Iyengars speak only to God.

Was that last line a reference to Ramanujan?

This was unfortunately the norm in his community at the turn of the century. A rather detailed study about the historical context of marriage among women in Ramanujam's community (Tamil Brahmins) is here: http://eprints.lse.ac.uk/46203/1/__lse.ac.uk_storage_LIBRARY...

From what I understand, it was common across many communities throughout India (though in Tamil Nadu, primarily among the Brahmins) for girls to be married before the onset of puberty (with consummation of the marriage only permitted post-menarche.. at least in theory). I do recall seeing a paper once that argued that the age of marriage actually became younger for some complicated reasons under British rule in the early 19th century.. not sure if that's believable.

As you might guess, I'm from the same community, and my great-grandmother was married at the age of 9 or 10. While one could attempt to rationalize and contextualize it, I think that's pointless: it was wrong then, as it is now.

I think the points raised are reasonable and, to my mind, not particularly partisan (though I would argue one party is more responsible for the current chaos by several orders of magnitude than the other one..).

The deeper issue this raises is, I suppose, a constitutional one paired with Long Now Foundation-type questions. How do we design institutions that can't themselves be changed too easily due to majoritarian whims, yet can evolve over decades and centuries as societies change. We certainly shouldn't expect the institutions and norms of today to precisely meet the needs of our descendants decades or centuries from now.

For the here and now though, my observation is this: Americans in general are allergic to learning from what other countries do. But really, as a very large country, we should be studying what smaller countries do and using them as experimental points of data and testing them out here. There are plenty of implementations of better, more responsive governance out there. Nothing's perfect, but saying 'we're number one' and plugging our ears is no solution.

Singapore is similar, in that pay for top public servants is competitive with top private sector pay. And they try to attract the best and brightest.

I don't think it will reduce the need for energy storage. If it does, it might be in some marginal cases and by a small amount. This is because the power generated using this approach is quite a bit less than what you can get from solar. So for any conventional uses, PV+storage will always be the winner. I think the real advantage for this might be for low-power, long-duration applications where battery cycles can be a challenge. The other big scenario is polar climates, where there's low solar insolation for several months.

Yes that distance matters in so far as getting the heat to the thermoelectric can be a bit more challenging. However I believe this has been investigated before and there are likely ways of doing it at least somewhat well.

There was an analysis done on the theoretical (Carnot/ 2nd Law) limits of using Earth's infrared emissions in this way: https://www.pnas.org/content/111/11/3927.abstract (Roughly 4 W/m2 for a system that purely exploited the radiative mismatch between outgoing and incoming long-wavelength radiation from the sky.

The bigger limit in our case is that we're using a thermoelectric generator - and achieving a relatively small temperature difference. We argued in the paper it might be possible with improved engineering and more favorable weather conditions to push performance to 0.5 W/m2.

In general, solar gets you far more power than this method ever will. The only advantage to combining the two might be to provide incremental power at night that improves the overall energy economics of the footprint associated with the solar panel.

And yes, a heat source would improve the power output. This has been the approach of an entire field of research that one might term 'waste heat recovery'. This encompasses everything from industrial sources to the human body or a campfire. The advantage, such as it is, of what we've done is that you don't need a source of heat besides the air itself.

Yep!

One way to understand this cooling effect is that it occurs because at wavelengths where greenhouse gases are not substantially absorptive, heat can effectively escape out (or at least get absorbed and sent back to you at a higher altitude). The actual mechanisms are more complex than I'm describing as the atmosphere's temperature and composition varies with altitude, but the net effect from the perspective of a surface facing the sky is that, if you're at the same temperature as the air around you, you will radiate more heat out than the sky sends back to you.

All that being said, this is not in and of itself a climate change solution in the way you might be imagining. Most surfaces on Earth are effective at radiating heat already, and do so (it's in climate models). The difference here is we're thinking about actively making use of the cooling effect from a device, or building-scale to offset energy uses.

Yes! Most natural materials have a relatively high emissivity at the infrared wavelengths associated with "typical" room / terrestrial temperatures. So in that sense, pretty much any material you might have (except for a highly polished metal that might have low emissivity) is suitable to get some cooling using the radiative cooling effect at night.

The fancier materials work is for two things: 1) selective emission which can allow the radiative cooler to get to a colder temperature than a natural material (many/most of which have relatively uniform emissivity), and 2) high solar reflectance at the same time, which can allow radiative cooling during the day as well.

Hi there - I'm the lead author of this paper. Not a big fan of this particular write-up.. it's not a solar panel at all! But happy to answer questions.

The NYT actually had a detailed write-up that I thought was quite accurate: https://www.nytimes.com/2019/09/12/science/solar-energy-powe...

Following the Tolkien reference, migrants trying to cross the border are like Sauron’s army? Orcs? I’m not sure this world needs more ways of dehumanizing the desperate people and refugees seeking better lives.

I admire the author's willingness to see possibilities for positive change here, including through restorative justice. It is especially admirable in the context of the fundamental violations and loss of trust that such harassment and assault continues to impose on so many women in their professional careers. I can also completely understand different reactions to this, including a deep sense of anger and betrayal.

We must all do better, and continuously seek to do so.

In the short term, there is clearly value to outing commonly-known 'secrets' such as this one, in this and many other industries.

Yes, it emits more radiation/ heat when hotter. A nice feature of radiation is that scales as T^4.

It's pretty durable on its own. That being said, as we've moved to the product stage we've packaged it in a way to protect it further.

The great thing is that we can use existing manufacturing processes (which we are already using) to do this extremely cheaply at large volumes. So the cost at scale will be competitive and make economic sense for customers. Our focus is on packaging this into a compelling product that delivers large electricity savings. Lifetimes of 20+ years are expected.

You can still get cooling, but you get less heat rejection per unit area in high humidity because of the effect you point out.

Sorry, that's the convention of the journal. It's W/m^2 -- heat rejection per unit area.

I'm one of the authors / people working on this. Yep, radiators like the ones on the ISS are pretty much the dominant/only ways to get heat out in space.

In response to your questions: yes, it can in fact cool below the ambient air temperature entirely passively (even during the day! -- which adds real value for cooling applications). We've shown in other recent work that you can use this effect to cool as much as 45-50°C below the ambient air temperature, if you insulate the radiator perfectly.

The reason this works here on Earth is that some upward thermal radiation isn't absorbed and re-emitted back to you. So if you start at the air temperature, looking upwards, you will be sending more heat out than the sky sends back to you. This allows an upward-looking surface to cool itself down until the heat going out and coming back to it balance out.