Finally someone wrote the article I wanted written about one of the infuriating parts of living in NYC: no countdown clocks for subway trains, for no good reason.
That’s why the MTA has tried to associate CBTC [a enormous overhaul of the signal system for the subway] with countdown clocks. New York riders crave realtime information about trains. They don’t care how they get it. So when Transit wants to drum up support for an obscure, costly, many-decades-long capital project to upgrade to CBTC, they always point to the clocks. (“Sustained Investment Makes Real-Time Information Possible,” declares one 2012 press release.) Reporters, struggling to make sense of a half-dozen interrelated projects, follow the MTA’s lead and assume that realtime train-location information depends on signal upgrades.
But that would make for some pretty expensive clocks, and it would make them awfully long in arriving. The F train, for instance, if it had to wait for CBTC to get realtime arrival information, wouldn’t see it until 2035.
It’s a misleading narrative. You can get countdown clocks without touching the signals. The MTA knows this.
An embarrassing symptom of municipal sclerosis.
- An analysis of the “rolling shutter” distortion effects in some popular pictures of propellors and other fast moving objects.
The NY Times covers drone racing:
(H/t Steve Hsu, who links more videos.)
- Tracking WT1190F.
- Should grand juries be abolished?
- CRISPR to be deployed to treat rare blindness in less than two years. H/t Scott Alexander. See also this excellent follow-up comment at Scott’s blog.
- You know where Coney Island Dogs were invented, right? Detroit.
- Jeff Kaufman on altruistic trade-offs and the parallels between global warming and animal suffering.
Bas Hensen from Delft gives a talk on the recent loophole-free demonstration of Bell’s inequality:
Incidentally, two other groups that were clearly in a very close race have just posted their loophole-free experiment: arXiv:1511.03189 and arXiv:1511.03190. (H/t Peter Morgan. Also, note the sequential numbers.) Delft’s group published as soon as they had sufficient statistics to reasonably exclude local realism, but the two other groups have collected a much larger sample, so their p-values are more like 1 in 10 million.
Nature covers twitter conversation between members of hiring committee where folks lament how bad impact factors and journal prestige are for sorting candidate…and then pretty much throw up their hands and keep doing it.
I think this is defeatism, perhaps combined with an unwillingness to face up to how poor our assessment mechanisms are. Have each candidate select their single best paper and read those. If it’s still too many papers, then literally choose N candidates at random, where N is the max number of papers you are willing to read, and throw the rest away. This is still a better method than using impact factors (although I can think of better ones). At least a random filter doesn’t distort incentives.
- A couple of small tribes have significantly more and more varied vocabulary dedicated to smell.
- Possibly high-impact, and a rare case of rational thinking in aid: “US Senators Mobilize on Improving Maternal and Child Health“.
I’m a sucker for jet packs. Whatever.
I’m pretty impressed with the claimed 10 minutes of flight time. I didn’t really think that was possible because of the weight of the fuel with a simple chemical propellants like kerosene. The fuel only weighs about 65 pounds, so it seems like you could extend the flight time by at least 50% using external fuel tanks. 15 minutes is a seriously long jet pack flight.
Superdeterminism is often held up as a reductio ad absurdum for the sorts of Bell loopholes that people entertain, but this isn’t completely fair. Critics are completely right that any experiment can be ignored, or taken as evidence supporting rather than disproving your position, if you assume sufficiently complicated conspiracies. But the complicated/implausible/inelegant aspect of the conspiracy is something that can change dramatically as you learn more.
I like to point to conservations laws (as suggested to me by someone I can’t remember) as a sort of super determinism that would seem like a ridiculous supposition if you first noticed them indirectly. “You’re telling me that if I compute some complicated function of velocities for N>>1 particles at some time, then let them interact chaotically, the function will take the same value later — completely fixing the speed of the final measured particle — even though the velocities are completely different!?! It would have to be a conspiracy!”
Faced with a local internet service provider that couldn’t provide modern broadband, Orcas Island residents designed their own network and built it themselves. The nonprofit Doe Bay Internet Users Association (DBIUA), founded by Sutton, Brems, and a few friends, now provide Internet service to a portion of the island. It’s a wireless network with radios installed on trees and houses in the Doe Bay portion of Orcas Island. Those radios get signals from radios on top of a water tower, which in turn receive a signal from a microwave tower across the water in Mount Vernon, Washington.
- If you need a short, but nice and clear exposition of the measurement problem, look no further than this guest post by David Wallace on Sean Carroll’s old blog. Maybe I’ve been doing this stuff for too long for my impression to tell me anything about accessibility, but I think Wallace is very good at laying out the important philosophical considerations very clearly and accessibly in a very short space. (Obviously, no answers are given.)
- Little by little, ever so slowly, Robin Hanson will turn the universe around. His comments.
- Lately I’ve heard a lot of people argue that it doesn’t make sense to give the Nobel prize to just 2 or 3 people, because big collaborations are so important in science. To me, this is silly. If you want to encourage and support collaborations, you should work on institutions and norms that are good for that — I think particle physics does a very good job here, so I would copy them — but prizes are not one of those thing. The entire point of a prize is to elevate a personality and heap status on them, and you can’t do that if it’s diffused over Dunbar’s number of people. To push this to it’s logical extreme, imagine how useless it would be to award the prize jointly to each of the thousands of physicists involved with a big experiment. Wouldn’t that be rediculous?
“Signaling and Productivity in the Private Financial Returns to Schooling”, Bingley et al 2015. [PDF] Abstract:
Does formal schooling contribute to individual labor market productivity or does it act as a signal to employers of predetermined labor market skills? We test for whether employers statistically discriminate between workers on the basis of their schooling, by assuming we can observe a proxy for worker productivity that the employer cannot – father, brother and co-twin earnings. Using population-based Danish administrative data, we find that employers initially statistically discriminate between workers on the basis of schooling, but schooling earnings differentials fall over time as employers learn about worker productivity. We further propose a novel test for job market signaling using differences in twin pair earnings growth, and find that signaling is important at the upper end of the schooling distribution – explaining a large proportion of the college wage premium.”
- Adam Davidson: “You’re Not Supposed to Understand the Federal Reserve“.
- Documentary on Australian Tent Boxing.
I think this is my favorite colorized historical photo.
Apparently it’s Washington DC, 1921.
- Gene editing advance.
- Genome sequencing drops to $1,000. HN comments.
- “Lytro announces world’s first light field VR video camera” (HN comments.)
Carl Shulman tracks how changes in animal farming tech affect consumption and animal-years per kg of animal product produced:
Summary: Selective breeding, drugs, and altered diets have greatly increased the quantity of milk, meat, and eggs produced per year of farmed animal life for multiple species, creating side effects that lowered the quality of life of farmed animals, and increasing consumption through lower prices. In the United States it appears that for some agricultural industries productivity increases since 1950 might have reduced farmed animal-years enough to outweigh the effect of falling prices. These include dairy, beef, and eggs. However, total animal-years of chickens raised for meat, the most populous farmed land animal, increased dramatically in total and per capita, despite a severalfold reduction in chicken-years per kg of meat sold. Increases in production efficiency may reduce demand for farmed animal-years in some mature developed country markets, while increasing demand in larger emerging markets. Further analysis using detailed income and price elasticity information, as well as welfare effects of overbreeding, could estimate net effects of technological change on animal welfare.
- Sam Altman of YCombinator releases the “Startup playbook“.
- Colorized photos of the unearthing of Tutankhamun’s tomb.
- Nature News: “CRISPR: A path through the thicket“.
This is the US military’s directive requiring that autonomous systems may only engage lethal or kinetic weapons under the direction of a human. (Non-lethal electromagnetic weapons can be fully autonomous.) H/t this article on the Navy’s small swarming power boats:
- Testing glasses that claim to improve color discrimination in the colorblind. I was familiar with a lot of this material, but some of it was new and it’s well presented. Also, this article (H/t escherplex) has a nice comparison of the spectral response curves for humans and the tetrachromatic European starling.
- “Shooting star illuminates Thailand sky” (brief GIF video).
Usually I don’t like the very common journalistic practice of blending a story on large-scale developments with human interest stories. (If your article is worthwhile, I don’t need to be tricked into reading it. And most human interest pieces are boring and/or I hate humans.) But this article on the long development of artificial hearts has some choice bits:
After pulling into a handicapped parking space, Williams unplugs his [artifical] heart’s air-compressor from the car’s charger, straps on a backpack that weighs roughly 14 pounds, and steps into the Southern California sun. As he walks up a wheelchair ramp to the coastal path, a man in an army fatigue hat and board shorts yells: “What are you doing, you’re not handicapped!” Williams stops and locks eyes with the pedestrian. “I don’t have a heart,” he responds, noticeably flustered. “What’s your disability?”
- The editorial board of the linguistics journal Lingua abandon Elsevier.
- Computer-generated email responses from Google.
- If you can imagine finding stories about commodity futures funny, go here.
80k Hours argues that philosophers are high-impact careers:
…the main reason why I think that philosophy is a high-impact area for research is that there are so many open questions that would radically change the value of all our activities. If non-human animals have similar moral status as humans do, or if we should think it’s morally important to create happy people, then the world’s moral priorities look radically different than we might have thought. We might be living in a moral catastrophe and not even know it; we need people to try to figure out if this really is the case. There are few other fields where conclusions in those fields can radically change your views on how you should live your life in the way that moral philosophy can. Moreover, compared to other areas of intellectual inquiry, the number of philosophers is very small. In some areas, at least, there seems to be significant potential to make progress on topics that would not otherwise have been addressed.
I agree with them, but note their philosophical background and connections potentially make them very biased.
- A very good distinction made by Noah Smith, between one-time efficiency gains and growth promoters. Worth pointing out that many regulation do have both efficiency costs and growth costs, though. Unnecessary professional licensing like for hair stylists both increases the cost of hair cuts and reduces innovation, e.g., one more barrier to profiting from an automatic haircutting robot.
The Sun in 4k resolution video
(You may want to download the video from YouTube using a downloader like this one.)
The flare at 28:05 is pretty spectacular.
In the context of an r/AskScience discussion of tardigrades, theguavashop explains a key structural difference between plant cells (which have a multi-micron thick cell wall) and animal cells (which do not):
Animal cells tend to be able to dehydrate and survive but if they over-hydrate they die, whereas plant cells are the opposite. When plant cells over-hydrate the cell wall keeps them intact while animal cells simply burst, however if plant cells dehydrate the cell membrane shrivels up and rips away from the cell wall causing death while animal cells can shrivel up and often survive until they are rehydrated.
- The Triumph of Humanity Chart.
- The Economist estimates value added by universities, by finding out how much more alumni earn than their incoming scores would suggest. Princeton does pretty bad, coming out with slightly negative value-added.
- Why Mathematica indices start at 1 rather than 0. Note that this is a good example of a StackExchange question that shouldn’t be closed. Just because people who don’t know the answer suspect that answers will be opinion-based doesn’t mean someone else doesn’t know an objective answer. In this case, speculative answers (like Murta’s) should have been down-voted, but the question should have remained open.
- Python namedtuples. I have found the Mathematica analog, Associations, to be very useful.
- Tesla autopilot avoids collisions.
- Tyler Cowen reports on the educational benefits of China’s recently relaxed one-child policy.
As I can attest, hospital are terrible at letting their patients sleep. (ACP version.) The recovery implications of good sleep are non-trivial.
Many of the author’s suggestions don’t seem that practical, though, especially about trying to get different nursing assistants to come in the room at the same time. (This will obviously cause them to waste lots of time sitting around waiting for their colleague to arrive.) The best suggestion seems to be to make “sleep protocol”, which I guess physicians can request, the default case for non-ICU patients.
However, I think completely autonomous vital signs would be totally do-able and would reduce, rather than increase, the burden on nurses. The vital signs in most US hospitals are: temperature, blood oxygenation, pulse rate, respiration rate, and blood pressure. It is feasible for all of these to be monitored continuously and autonomously with only very small amounts of new technology. In particular, temperature, pulse rate, and respiration rate should be detectable with infrared and visible cameras, while blood oxygenation and pressure should require no more than a finger sleeve or wrist strap.
- Megaproject: The Gotthard Base Tunnel.
The headline for this article “Science papers rarely cited in negative ways” is pretty useless, and clearly turns on how one defines “rarely” and “negative”, and really can’t be assessed by an outsider with no experience in a field. But this is unambiguous and notable:
The analysis also suggests that negative citations are most likely to come from other researchers who are close in disciplinary affiliation and “social distance” to the critiqued authors — which is probably no surprise — but relatively far in geographical distance. The latter suggests that social factors — the awkwardness of contradicting someone whom you are likely to bump into in person — may play a part in science’s self-scrutiny.
- The instrument choice of the Europa Multiple-Flyby Mission, formerly known as the Europa Clipper, was finalized earlier this year.
- Peter Woit reports on a new film/series being developed about Lev Landau. Anyone who has been to my office knows I have almost finished collecting the complete set of Landau & Lifshitz…
- A claim: Selling cars direct to the consumer could save 6 percent on total costs.
- The first time the far side of the Moon, which is tidally locked to face away from the Earth, was ever seen was by the Soviet probe Lunik 3. (This was some 8 years before humans onboard Apollo 8 saw the far side themselves.) Lunik 3 required highly specialized temperature-resistant and radiation-hardened photographic film that the US could produce but had not yet been achieved by Soviet scientists. In the midst of the space race, the Soviets obtained the film from high-altitude spy balloons, released by the US to fly over Soviet territory, as part of the American Genetrix project. The Soviets shot down the balloons and then recovered the valuable film from the wreckage.
- Effective Altruism newsletter.
These work well when you open them up on a smart phone: Higher res, “look-through” (magic eye) technique. Lower res, with Charon, “cross-eyed” technique. Heck, why not a cross-eyed one of Jupiter?
- Robin Hanson compares two origins of moral progress: wealth or discovery of moral truth.
LaTeX in commentsInclude [latexpage] to render LaTeX in comments. (More.)
- How to think about Quantum Mechanics—Part 1: Measurements are about bases (11)
- Wigner function = Fourier transform + Coordinate rotation (6)
- Ninnat Dangniam [latexpage] Mahmoud, one has to be careful how to define “quantumness” based on the negavitity... – Dec 28, 1:54 AM
- Mahmoud Now I know that the negative values of Wigner function represents of the non-classical state... – Sep 13, 1:18 PM
- Jess Riedel Thanks Lucy. Sorry about the spam filter; the options provided by Wordpress are crummy and... – Aug 26, 8:39 AM
- Lucy Keer Oops, that was a bit unclear - meant to say that I tried to add... – Aug 26, 7:45 AM
- Lucy Keer Thanks very much for writing this up! I had very similar frustrations recently in trying... – Aug 26, 7:40 AM
- Links for April-May 2018 (8)
- Devin Bayer Hi Jess, I found your blog via another physics blog and subscribed because I found... – Aug 04, 3:29 PM
- Top posts (2)
foreXiv by C. Jess Riedel is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.