- Are those cocky physicists-turned-biologists living up to their reputation and embarrassing themselves by ignoring epistasis, epigenetics, and gene-gene interactions? Steve Hsu says no, citing the strong success of additive models in twin studies, and the theoretical explanation from stability for the same.
An excellent video (from here) depicting a 1956 vision of the future of autonomous driving.
(H/t Tyler Cowen.)
- I’m pretty skeptical of the feasibility Elon Musk’s Hyperloop concept, based on earlier criticism, but an unaffiliated company just signed a contract for the land to build a 5-mile test track, and Musk himself claims a different test is coming to Texas. Note however that the first company is long on hype, short on details.
All these amateurs and celebrities have been talking about the long risk of recursively self-improving artificial intelligence, but don’t the actual AI researchers think this is a bunch of hooey? Only if you cherry pick, notes Scott A. In particular, if you’re willing to trust the survey skills of people with skin in the game, then
…a survey of AI researchers (Muller & Bostrom, 2014) finds that on average they expect a 50% chance of human-level AI by 2040 and 90% chance of human-level AI by 2075.
- If you are a freshman or sophomore undergrad, GiveWell is hosting a one-week summer fellowship that may be of interest.
- Rockets engine tanks are often designed with excess hydrogen relative to their oxidizer because the unburnt hydrogen has a higher exit velocity for a given temperature, increasing specific impulse.
I have some comments on this critique of the PhD Thesis that’s been making the rounds.
He would much prefer to see theses’ introductory sections “written along the lines of a good review article, where the student does a critical appraisal of the state of the field”
Yes! A well-written thesis continues to be a very valuable contribution to the literature, but it is the parts that are *not* original work that are most useful. The reason is that older researchers in a field have almost no incentives to write good and truly introductory review papers, and the introductory sections of a thesis are often the best point of entry.
However, most theses are not well written because student don’t have much incentive either.
Hence, theses become bloated with “page after page of methods”, along the lines of: “I pipetted 2.5ml of this enzyme into that tube.”
Yea, it’s boring for professor on the thesis committee to read, but this sort of stuff is very valuable for students and postdocs, who often struggle to reproduce poorly-documented results from other labs.
“Communication within the science world and with the public is becoming shorter and snappier, yet our PhDs still seem to be stuck in the 1960s.”
Ahh yes, just what we need. Thesis-by-tweet…
- Here is a good interview with Ned Block on (among other topics) distinguishing access consciousness from other things that are called consciousness. He mentions a new book by researcher Stanislas Dehaene that gives a great introduction to what is empirically known about “conscious access”. Dehaene indulges in a bit more philosophizing than I think his skills warrant and, as Block points out, he does a bad job distinguishing between conscious access and other forms of consciousness (mostly because he dismisses all forms of the later as scientifically meaningless). That said, I strongly recommend Dehaene’s book.
- The LHC has now seen first collisions at 13 TeV.
The United Arab Emirate is planning a Mars mission:
- Machine learning and up-scaling Japanese prints. (HN discussion.)
- Anscombe’s quartet illustrates the limitations of common statistics. (H/t eric.)
- On the mystery of sloth defecation.
- Reading ancient scrolls made un-unrollable by the Mount Vesuvius eruption, using x-ray scans.
- Scott Aaronson on the the Logjam attack.
- Security questions (“What was the name of your first pet?”) are terrible. They’re not secure, and people forget them. (H/t Michael Blume.)
Here at PI we had a goose that made a nest on the ledge up on the 4th floor. I was wondering whether the goslings would be able to survive the initial plunge to the ground after they hatch, and this video made me more optimistic:
(Our goslings all made it, unharmed.)
Behold, the tortoise skeleton:
Further details from exxocet:
…the weird thing about the tortoise/turtle skeleton is those struts near the front, the scapula/shoulder blade is INSIDE the ribcage….How the hell did it get in there when most shoulder blades are on the outside of the ribcage?..Pretty cool development from embryo show us that the close ribs move backwards and reduce first to allow for the scapula to sneak inside.
- Altruism, genes, and the sad story of George Price.
- Michael Nielsen is joining Recurse.
A (human-controlled) Da Vinci surgical robot sews a grape back together:
- A whole mouse brain has been “preserved at the ultrastructure level for electron microscopic imaging of its entire connectome.” (H/t Robin Hanson.)
- In 1975, Soyuz 7K-T No. 39 was an unsuccessful Soviet mission to dock with the orbiting Salyut 4 space station, but aborted before reaching orbit. During the abort procedure, the cosmonauts experienced over 21 g, much higher than the abort design max of 15 g. However, they and their capsule returned to Earth safely.
Footage from Berlin July 1945:
The slip-and-fall prevention programs at LANL — this is 100% real — helped give me the single biggest cynicism I now have about large organization. I used to think that organizations were inefficient and dehumanizing because of various incentive and communication issues that prevented good humans from working together. But now I believe that large organization actually destroy the souls of the people inside them. It’s not just a matter of frictions. The human beings themselves have been infected.
Luckily, there are highly useful and reasonably priced technological spin-offs.
- Nature Climate Change: Battery packs are getting cheaper fast.
- Is there no distinction between great scientists and hypsters?
Carl Schulman summarizes an example of bad study design:
Original underpowered study: 40 subjects. Meta-analysis of follow-on studies inspired by its publication and promotion, which showed the effect was a false positive: 7000+ subjects, 16 more studies. A striking example of how publishing underpowered and p-hacked studies waste far more resources than it would cost for the original authors to use adequately powered pre-registered designs.
P-hacking is not a victimless crime.
I gleefully continue to quote Weinberg (whose status is beyond reproach) in support of the idea that, yes, quantum mechanics really still is something we should worry about:
Horgan: Will further research help dispel the paradoxes of quantum mechanics, or might reality in some sense always be unintelligible?
Weinberg: I think our best hope is to find some successor theory, to which quantum mechanics as we now know it is only a good approximation.
- If it’s true that earlier proposals to probe spacetime foam are bunk, it’s crazy that this just sits on PRD. There have been dozens of papers on this idea in high-profile journals. Will this lead to embarrassing retractions or, alternatively, a convincing and widely accepted debunking? No, probably just silence.
Still have a hard time believing that quadracopters this fast and agile are real.
- More from Scott A.: How plausibly deniability and the principal-agent problem combine to give bad moral trade-offs in medicine.
Amazon delivery to your trunk?
Packages could soon be delivered to the boot of your Audi as part of a trial involving the car maker, Amazon and DHL…the system aims to end the frustration of missing the arrival of a package being delivered to home or work. Instead, Audi owners will be able to use their car as a shipping address for items ordered online….Using Audi’s in-car communications system, Connect, DHL delivery drivers would track a customer’s vehicle over a specified period of time and then use a digital access code to unlock the boot, the car maker said. This code would then expire as soon as the boot was shut.
- Nick Bostrom now has a Ted talk on recursively self-improving artificial intelligence.
The weirdest strategic reserves:
And what would follow a nuclear conflict? Well, countries wanted back-up power in case their electricity systems failed as a consequence of an electromagnetic pulse from a nuclear bomb. The Soviet Union kept and serviced a fleet of steam-powered trains — the strategic steam reserve — that could run on coal. The strategic steam reserve still exists today, but it has been decaying since the breakup of the Soviet Union in 1991.
- Why aren’t we domesticating tigers through selective breeding? Can we not achieve most of the gains in the first dozen or so generations, a la the Silver Fox experiment? I feel like we’re missing out on a lot!
Dieter Zeh, one of the founding fathers of decoherence, on Wigner and the measurement problem:
Eugene Wigner even suggested explicitly the possibility of an active influence of consciousness on the physical world [E.P. Wigner, in The Scientist Speculates, L.G. Good, edt. (Heinemann, London 1962), p. 284], but dropped this proposal when he learned about the concept of what was later called decoherence [E.P. Wigner, private communication (1970)].
I sure would like to see that private communication…
So after a couple of studies said that grant review committee did no better than chance, there is a new study that says they actually add some value! A standard deviation in review evaluation score gives 19% fewer high-impact publications, 15% fewer citations and 14% fewer patents. Given the tremendously skewed distributions of citations (with the top 5% attracting 50% of the citations, or whatever), this seems like a very modest accomplishment by the review committees.
It would have been a lot more useful to also know how a percentile increase on the review score translated into a percentile increase on the citation distribution. We already the citations are highly skewed from a winner-take-all dynamic, so even if you just barely increase your chance of funding the top paper as opposed to the second-to-top paper, your expected number of citations might jump a lot.
Of course, if you think citations are roughly proportional to scientific value, then this doesn’t matter. The absolute number of citations is the important thing, and it really is worth it to eek out a slightly higher chance of funding the top paper. But if you believed that, you’d think from the exponential explosion in citations that science today is vastly more valuable than even a few years ago, and that physics hadn’t stopped making much progress back around 1970….
How about searching for extraterrestrial intelligence by looking for the byproducts of their galactic accelerators probing the Planck scale? This is probably a bit like medieval scholars estimating the size of the cloth you’d need to sail to the moon, but fun nonetheless. The author mentions that the Planck scale is about 10 XeV, with a footnote stating
The SI prefixes for very large numbers are E (1018; exa), Z (1021; zetta),
and Y (1024; yotta). No larger SI prefixes have been decreed, but I adopt symbols that continue in reverse alphabetical order: X (1027), W (1030), and V (1033), as proposed (sometimes in jest) by Jeff Aronson, Jim Blower, and Sbiis Saiban.
An aircraft window has three panes. The outer and middle pane are hard glass, and each are capable of withstanding the pressure differential on their own. The inner pane is just non-airtight plastic (presumably easily replaceable), and is designed to take the smudges and scratches from passenger elbows.
The interesting part is that there is a small hole through the middle pane, so that the gap between the outer pane and the middle pane is at cabin pressure. Apparently this cuts down on frost and fog that would otherwise form on the middle pane. If the outer pane fails, this gap drops to exterior pressure and the middle pane must suddenly bear the full pressure differential. The cabin air does leak through the hole in the middle pane, but only at a relatively slow rate that can be compensated by the plane’s pressurization system.
Neat discussion of cell line infections, i.e., truly infectious cancers:
…we have here the most abrupt evolutionary transition known, a jump from mammal to one-celled organism in a single step. For this transmissible tumor, also called canine venereal sarcoma, is in every sense an independent infectious organism, just as much so as Salmonella typhi or Plasmodium falciparum. It reproduces and metabolizes. Although descended from dogs, it is genetically different from dogs, with a different chromosome number (57 rather than 78), due to extensive chromosomal rearrangements. Since it cannot, as far as we know, exchange genetic material with dogs, it is a new species….Although its phenotype differs considerably from dogs (no brain, no bones, no eyes, no fur, asexual) classification by descent clearly implies that it is a canid and mammal – certainly the most unusual mammal ever discovered.
If cell line infections are reasonably common, it might be that immunological rejection of foreign tissue, which so complicates organ transplants, is a necessary function rather than a side-effect.
A number of parasitic organisms have lost so many nonessential functions that it is almost impossible to tell what they once were by any methods other than molecular biology. For example, the organism that causes ‘whirling disease’ in trout is a degenerate jellyfish.
How it’s made, pasta edition:
LaTeX in commentsInclude [latexpage] to render LaTeX in comments. (More.)
- How to think about Quantum Mechanics—Part 1: Measurements are about bases (9)
- 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)
- Links for July 2018 (3)
- How to think about Quantum Mechanics—Part 1: Measurements are about bases (9)
foreXiv by C. Jess Riedel is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.