- John Baez reviews the surprising richness in the (non-)well-posedness of dynamical physics theories. (This is the first of a multi-part series; see Baez’s sidebar.)
- Photos from the national Beard and Mustache competition. (Scroll down.)
- From out of nowhere, Blue Origin reveals plans for Falcon Heavy competitor. (/r/SpaceX discussion.)
“China will resurrect the world’s largest plane“:
The sole operational An-225 began flying in 1988, initially carrying the Soviet Buran, a 105 ton reusable spaceplane, on its back. It was put into storage after the Soviet collapse, but restored and put into commercial service in 2002. Since then it has been rented out, flying super heavy cargos like gas and wind turbines, as well as military supplies for NATO forces in the Middle East.
Time lapse video of bacteria growth evolving resistance to antibiotics:
(H/t Alex Taborrok.)
The Pagoda of Hōryū-ji (“Temple of the Flourishing Law”) in Japan is the world’s oldest extant wooden building, built using wood felled in 594. The Economist uses this factoid as the intro to their article on building wooden skyscrapers. Concerning the fire risk:
In general, a large mass of wood, such as a CLT floor, is difficult to burn without a sustained heat source—for the same reason that it is hard to light a camp fire when all you have is logs. Once the outside of the timber chars it can prevent the wood inside from igniting. The big urban fires of the past, such as the Great Fire of London, which occurred 350 years ago this month, were mostly fuelled by smaller sections of timber acting as kindling. Prospective tenants would doubtless need lots of reassurance. But with other fire-resistant layers and modern sprinkler systems, tall wooden buildings can exceed existing fire standards, reckons Benton Johnson, a project leader with Skidmore, Owings & Merrill.
- How Holden Karnofsky says his thinking has changed. Good reading.
- Rumors of internal reboot of Apple’s self-driving car program.
- New galactic simulations suggest supernovae are sufficient to account for number of observed dwarf galaxies orbiting Milky Way, which previously could not be reproduced, weakening arguments that it was evidence of nontrivial dark matter properties. Naively, I’m worried this is a case of “tweak things until you get the answer you expect”.
- Also: Apparent discovery of galaxy made up of 99.99% dark matter. (Washington Post coverage.) More concretely, astronomers found a tiny collection of stars whizzing around much faster than makes sense. There’s definitely a whiff of epicycles here.
- Sabine covers recent work on nuclear parameters that weigh against anthropic arguments.
- Excellent recent work on what’s known about the purpose of various pupil shapes in animals. (H/t Will Riedel.)
- The Mineralarians eschew eating anything that was once alive.
- Peter Woit nicely summarizes some of the recent funding activities of the Templeton foundations. I commented in the discussion to clarify how Templeton’s funding is actually being distributed to math and physics.
SpaceX signed up a customer to re-fly a first stage. Then a different SpaceX rocket blew up. Musks says a crew would have survived, as the launch escape system is fast enough for them to evacuate. Here’s a video overlay of the escape system test and the recent explosion.
Apparently, the Apollo program used a simple broken-circuit trigger, so the escape system might really be initiated that quickly after the explosion:
On the other hand, the only real-world use of a launch escape system with crew on board was the Soviet Soyuz 7K-ST No. 16L which, because it used a very different design, took several seconds to actually engage. Luckily, in that case the fire was burning slowly and the crew survived:
- Group of four completely co-dependent viruses discovered. Mosquitoes exposed to any three are not infected.
- Some aspects of Jewish and Islamic law are based on sunrise and sunset, which have to be modified for people living at high latitudes.
- Forest-firefighting artillery.
- Proxima B.
- Peter Woit on the settling of some SUSY bets, and Robin Hanson’s original essay on betting to improve science.
- Distinguishing bolts from screws.
- A wrinkle in the simulation argument.
- Shipping traffic.
- Guinea worm is on the ropes, but seems to survive in canine reservoirs.
More bad news for me with my bet with Paul: Uber’s First Self-Driving Fleet Arrives in Pittsburgh This Month
Starting later this month, Uber will allow customers in downtown Pittsburgh to summon self-driving cars from their phones, crossing an important milestone that no automotive or technology company has yet achieved….Uber’s Pittsburgh fleet, which will be supervised by humans in the driver’s seat for the time being, consists of specially modified Volvo XC90 sport-utility vehicles outfitted with dozens of sensors that use cameras, lasers, radar, and GPS receivers. Volvo Cars has so far delivered a handful of vehicles out of a total of 100 due by the end of the year. The two companies signed a pact earlier this year to spend $300 million to develop a fully autonomous car that will be ready for the road by 2021…In Pittsburgh, customers will request cars the normal way, via Uber’s app, and will be paired with a driverless car at random. Trips will be free for the time being, rather than the standard local rate of $1.30 per mile.
Should this be interpreted as evidence that Uber/Volvo has tech that Google doesn’t, or that they are just more aggressive at involving customers? Possible counterpoint from seibelj:
If we don’t have self-driving cars everywhere on highways moving cargo, then we won’t have self-driving taxi cabs for many years after whenever that happens. City driving, where Uber can actually make money with the density of people, is the hardest driving of all, and will be the last place where self-driving cars without any human operator take over.
- Preliminary GiveWell investigation finds that voluntary medical male circumcision is within the cost-effective range of other priority programs. I have been pretty impressed with GiveWell’s level-headed assessment of politically charged topics.
- The origin of the Coast Guard phrase “You have to go out, but you don’t have to come back“.
- The fraction of Americans who agree “most people can be trusted” has fallen by a third since 1972. Increased demand for regulation is correlated with not just general distrust, but with distrust of the government.
- Factors that will be important for a sub-2-hour marathon.
- A case for moving the US nuclear posture to commit to no-first-use.
Development of the Apollo spacesuit:
“7 mistakes I made when I published my academic book“. An interesting bit on open access:
…the series editors had already negotiated with the publisher to have the books in the series be accessible and downloadable via the publisher’s website….more and more presses are offering options like this these days, so it’s worth asking about it wherever you end up taking your manuscript.
H/t Tyler Cowen. Also by way of him: The Greenland shark is the oldest living vertebrae in the world, with an expect lifetime of at least 272 years, and probably more like 4 centuries. (Washington Post coverage.)
- Colorizebot bot patrolled reddit for a couple weeks, fulfilling user requests to colorize B&W photos based on a neural net. Interestingly, it did a good job of finding realistic colors when given the B&W version of fantasy images that originally had unrealistic colors.
- Influential Chinese-American physicist Chen-Ning Yang publicly argues that China should not build the LHC successor. See especially John Baez’s coverage of the retort.
- Transmitting data across an air gap using sound generated by a hard drive actuator.
- Surprising to me: this excellent visualization seems to give strong evidence that the historically static upper limit on human age should not be expected to continue. Life expectance for folks who are quite old (> 85) is essentially unchanged since UK data collection started in 1845, but this looks to be simply because it hasn’t been worthwhile to apply resources to extending it when most people die earlier. The same flatness of life expectancy used to be true for folks at younger ages (e.g., 60), but then began improving as mortality for younger ages was largely suppressed. This is an excellent example of nonobviousness of how to properly do trend extrapolation. (H/t peripitea.)
- ChemArXiv. Yep.
- The village of Dull, Scotland is a sister city of the U.S. town of Boring, Oregon.
- Yes, adult intelligence declines with age, starting in the 30’s or earlier. Of course, adults gather skills and knowledge at the same time, which more than compensates in terms of productivity until they hit a peak in their 40s or 50s. But you should expect to hit your peak earlier the more your field depends on raw intelligence rather than skill and experience.
- Wild polio crops back up in Africa after it was suspected of being eradicated. Incidentally, vaccine-derived (not wild) polio is an interesting tail risk of the vaccine process.
Squirrel carries gopro up tree:
- Sabine Hossenfelder delves into the psychology of well-meaning and motivated cranks through the first-hand knowledge she got by selling her time to them. (Minor: I object to the idea that “In physics… that ‘demarcation problem’ is a non-problem, solved by the pragmatic observation that we can reliably tell an outsider when we see one.” This is just begging the question: we know we’re better than the crackpots because we talk like us!)
- The hygiene hypothesis continues to fascinate, especially with the possible connections to the recently fashionable gut flora research. The allergy-protection benefit of early childhood exposure are uncertain, but is there any downside?
- The Charity Science team got real serious about doing the research on what charitable startup ideas are most promising. (H/t Michael Wiebe.)
- Mathematica 11 finally makes the debugging process non-horrendous: “Messages now give an immediate option to locate the code that issued the message.” Or at least it claims to; haven’t tried it yet. It looks like a GUI for exploring a stack trace. This, of course, is not the same thing as finding the exact line (when possible) that resulted in an error. And Courier has been replaced by a Sans Serif font. Look here for more quirk fixes that long-time users will appreciate.
The increase in quality for the results of this face transplant, compared to earlier patients, is hard to believe:
The video includes before and after pictures, including the donor, plus extensive video. It’s not too graphic given the subject matter, but the man’s appearance between his accident and the transplant surgery is disturbing. This New Yorker article describes his heroic actions as a firefighter that led to his grievous injury.
Diverse applications of the Model T:
…the Model T was (intentionally) almost as much a tractor and portable engine as it was an automobile. It has always been well regarded for its all-terrain abilities and ruggedness. It could travel a rocky, muddy farm lane, ford a shallow stream, climb a steep hill, and be parked on the other side to have one of its wheels removed and a pulley fastened to the hub for a flat belt to drive a bucksaw, thresher, silo blower, conveyor for filling corn cribs or haylofts, baler, water pump (for wells, mines, or swampy farm fields), electrical generator, and countless other applications. One unique application of the Model T was shown in the October 1922 issue of Fordson Farmer magazine. It showed a minister who had transformed his Model T into a mobile church, complete with small organ.
During this era, entire automobiles (including thousands of Model Ts) were even hacked apart by their industrious owners and reconfigured into custom machinery permanently dedicated to a purpose, such as homemade tractors, ice saws, or many others. Dozens of aftermarket companies sold prefab kits to facilitate the T’s conversion from car to tractor. The Model T had been around for a decade before the Fordson tractor became available (1917–18), and many Ts had been converted for field use. (For example, Harry Ferguson, later famous for his hitches and tractors, worked on Eros Model T tractor conversions before he worked with Fordsons and others.) During the next decade, Model T tractor conversion kits were harder to sell, as the Fordson and then the Farmall (1924), as well as other light and affordable tractors, served the farm market. But during the Depression (1930s), Model T tractor conversion kits had a resurgence, because by then used Model Ts and junkyard parts for them were plentiful and cheap.
Like many popular car engines of the era, the Model T engine was also used on home-built aircraft (such as the Pietenpol Sky Scout) and motorboats.
- Robin Hanson responds to the claim that the em era, even if it arrived first, would lead so quickly to the era of de novo AI that studying ems isn’t valuable. Also from him: “Conferences serious @ truth assign a critic to each speaker. Those don’t reveal that not serious.”
Leopard falls in large well in Pimpalgaon Siddhanath, a village in west-central India. It is rescued from drowning by the lowering of a rope-suspended cage:
- Lonnie Johnson: The father of the Super Soaker. (Excellent short-form autobiography.)
- Laser brooms are for cleaning up space debris.
Battle for Castle Itter:
The Battle for Castle Itter in the Austrian North Tyrol village of Itter was fought on 5 May 1945, in the last days of the European Theater of World War II. Troops of the 23rd Tank Battalion of the 12th Armored Division of the US XXI Corps led by Captain John C. “Jack” Lee, Jr., a number of Wehrmacht soldiers, and recently freed French VIPs defended Castle Itter against an attacking force from the 17th SS Panzergrenadier Division until relief from the American 142nd Infantry Regiment of the 36th Division of XXI Corps arrived….The French prisoners included former prime ministers, generals and a tennis star. It may have been the only battle in the war in which Americans and Germans fought side-by-side. Popular accounts of the battle have called it the “strangest” battle of World War II.
- Tinnitus shares a lot of the same psychological pathology as chronic pain.
- Avi Loeb at Harvard Astronomy points out that there was a few million years during the cosmological dark ages when the CMB bath itself allowed for liquid water, and that this could contain the majority of all matter that has even enjoyed the physical conditions and chemical precursors for life, as measured by kilogram-seconds during the history of the universe up to current day.
In the redshift range 100≲(1+z)≲137, the cosmic microwave background (CMB) had a temperature of 273–373 K (0–100°C), allowing early rocky planets (if any existed) to have liquid water chemistry on their surface and be habitable, irrespective of their distance from a star. In the standard ΛCDM cosmology, the first star-forming halos within our Hubble volume started collapsing at these redshifts, allowing the chemistry of life to possibly begin when the Universe was merely 10–17 million years old. The possibility of life starting when the average matter density was a million times bigger than it is today is not in agreement with the anthropic explanation for the low value of the cosmological constant.
- Jason Ketola covers New Harvest 2016: Experience Cellular Agriculture.
- The 750 GeV diphoton excess vanished. Physicist (especially theorists) ought to be more embarrassed than this.
Talk about first-world problem solutions:
(H/t Tyler Cowen.) I don’t think it will materialize, but fingers crossed.
- The knowledge and control of laboratory mice is crazy.
- The National Poo Museum.
LaTeX in commentsInclude [latexpage] to render LaTeX in comments. (More.)
- Legendre transform (4)
- Branches and matrix-product states (6)
- Jess Riedel This prompted me to take an old email where I listed some models of branching... – Oct 12, 3:16 AM
- interstice Thanks. Do you know of any systems, toy or real, where we can identify a... – Oct 11, 10:06 PM
- Jess Riedel Great question. It is not obvious that we should define branches from the tensor structure... – Oct 10, 8:00 PM
- interstice Right, so to argue that the branches evolve independently, one must first define what branches... – Oct 10, 4:19 PM
- Jess Riedel You're right that the criteria for defining branches I give in the paper doesn't make... – Oct 05, 2:33 PM
- interstice I have a stupid(?) question. The criteria you give in the paper doesn't involve time-evolution... – Oct 05, 12:36 PM
- Comments on Weingarten's preferred branch (1)
- Links for August-September 2017 (2)
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