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[One from the archives, a previously unpublished short story I wrote c. 2017 on the theme of BASE jumping.] Why anyone thought a prison on the Moon was a good idea was beyond me. Remote, dangerous, inhospitable, to be sure. But certainly not impossible to escape from, as I was about to show. I had been ‘quartered’ in Block D, formerly optical scientist research and habitation module. Half buried in lunar dirt, the squints had wanted light, so Block D had some narrow slit-like windows near the ceiling, unlike the other blocks. From this window I could watch the Earth …
A quick note to formalize some observations on elite organization dysfunction. The Space Mirror Memorial at Kennedy Space Center in Florida commemorates the 25 US astronauts who have died in flight. Ron Dittemore is the retired former Space Shuttle program manager who was ultimately responsible for the series of decisions that resulted in the Columbia disaster, which killed seven of the lost 25 astronauts. Throughout my career I’ve become increasingly obsessed with a particular and fairly obscure form of institutional failure. I haven’t seen much written about its general form, so I’m writing this post to collate my thoughts. Dittemore’s …
I don’t ordinarily write about events “in the moment” but for this I will make an exception, as I was personally affected. Caveats aside, my family and I are safe, we evacuated for several days, and due to heroic efforts by professional firefighters and psychotically brave neighbors, my house and most of my neighborhood escaped destruction. We were the lucky ones – by far. In 2019, as my wife and I were house hunting, we inspected multiple homes in the Pasadena area. Every house we looked at in Altadena burned to the ground last week. I watched the Eaton fire …
I wanted to gain better insights into the Salton Sea level, evaporation, inflows and outflows. Step one was to gather publicly available data about its level, and collate it into a single graph. Here we see that despite the continual formation of Salton Sea advisory committees, the water level increased about 12′ after 1950, flooding many coastal resort towns, and then began a precipitous drop in about 2000. [Edit: If you enjoy this kind of thing, you may find a career at my company, Terraform Industries, rewarding. We’re hiring smart ambitious people in Los Angeles to bridge the gap between solar energy …
Part of the Mars Trilogy Technical Commentary Series. Contains spoilers for this chapter and earlier chapters. Google Mars .kml. Literary commentary podcast. “Shikata Ga Nai” Japanese for “What else can we do?” “It is what it is,” “There is no other choice.” The final chapter of Red Mars is told from Ann’s perspective. In the previous chapter, she learned that her son Peter may have been on the space elevator when the Bogdanovists cut it down. In the italicized opening pages of this one, we learn that Peter was on the elevator “Bangkok Friend” but, along with the other inhabitants, …
More in science
My post last week clearly stimulated some discussion. I know people don't come here for political news, but as a professional scientist it's hard to ignore the chaotic present situation, so here are some things to read, before I talk about a fun paper: Science reports on what is happening with NSF. The short version: As of Friday afternoon, panels are delayed and funds (salary) are still not accessible for NSF postdoctoral fellows. Here is NPR's take. As of Friday afternoon, there is a new court order that specifically names the agency heads (including the NSF director), saying to disburse already approved funds according to statute. Looks like on this and a variety of other issues, we will see whether court orders actually compel actions anymore. Now to distract ourselves with dreams of the future, this paper was published in Nature Photonics, measuring radiation pressure exerted by a laser on a 50 nm thick silicon nitride membrane. The motivation is a grand one: using laser-powered light sails to propel interstellar probes up to a decent fraction (say 10% or more) of the velocity of light. It's easy to sketch out the basic idea on a napkin, and it has been considered seriously for decades (see this 1984 paper). Imagine a reflective sail say 10 m\(^{2}\) and 100 nm thick. When photons at normal incidence bounce from a reflective surface, they transfer momentum \(2\hbar \omega/c) normal to the surface. If the reflective surface is very thin and low mass, and you can bounce enough photons off it, you can get decent accelerations. Part of the appeal is, this is a spacecraft where you effectively keep the engine (the whopping laser) here at home and don't have to carry it with you. There are braking schemes so that you could try to slow the craft down when it reaches your favorite target system. A laser-powered lightsail (image from CalTech) Of course, actually doing this on a scale where it would be useful faces enormous engineering challenges (beyond building whopping lasers and operating them for years at a time with outstanding collimation and positioning). Reflection won't be perfect, so there will be heating. Ideally, you'd want a light sail that passively stabilizes itself in the center of the beam. In this paper, the investigators implement a clever scheme to measure radiation forces, and they test ideas involving dielectric gratings etched into the sail to generate self-stabilization. Definitely more fun to think about such futuristic ideas than to read the news. (An old favorite science fiction story of mine is "The Fourth Profession", by Larry Niven. The imminent arrival of an alien ship at earth is heralded by the appearance of a bright point in the sky, whose emission turns out to be the highly blue-shifted, reflected spectrum of the sun, bouncing off an incoming alien light sail. The aliens really need humanity to build them a launching laser to get to their next destination.)
Recent results show that large language models struggle with compositional tasks, suggesting a hard limit to their abilities. The post Chatbot Software Begins to Face Fundamental Limitations first appeared on Quanta Magazine
A tour of interesting developments built in the last two decades
Is that immigrant high-skilled or do they just have a fancy degree?
Everything, apparently, has a second life on TikTok. At least this keeps us skeptics busy – we have to redebunk everything we have debunked over the last century because it is popping up again on social media, confusing and misinforming another generation. This video is a great example – a short video discussing the “incorruptibility’ […] The post Incorruptible Skepticism first appeared on NeuroLogica Blog.
