nhaliday + popsci   166

What's Wrong With Growing Blobs of Brain Tissue? - The Atlantic
These increasingly complex organoids aren't conscious—but we might not know when they cross that line.

I don't know why you would even *want* to do this tbh... What's the application?
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april 2018 by nhaliday
How do you measure the mass of a star? (Beginner) - Curious About Astronomy? Ask an Astronomer
Measuring the mass of stars in binary systems is easy. Binary systems are sets of two or more stars in orbit about each other. By measuring the size of the orbit, the stars' orbital speeds, and their orbital periods, we can determine exactly what the masses of the stars are. We can take that knowledge and then apply it to similar stars not in multiple systems.

We also can easily measure the luminosity and temperature of any star. A plot of luminocity versus temperature for a set of stars is called a Hertsprung-Russel (H-R) diagram, and it turns out that most stars lie along a thin band in this diagram known as the main Sequence. Stars arrange themselves by mass on the Main Sequence, with massive stars being hotter and brighter than their small-mass bretheren. If a star falls on the Main Sequence, we therefore immediately know its mass.

In addition to these methods, we also have an excellent understanding of how stars work. Our models of stellar structure are excellent predictors of the properties and evolution of stars. As it turns out, the mass of a star determines its life history from day 1, for all times thereafter, not only when the star is on the Main Sequence. So actually, the position of a star on the H-R diagram is a good indicator of its mass, regardless of whether it's on the Main Sequence or not.
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december 2017 by nhaliday
How sweet it is! | West Hunter
This has probably been going on for a long, long, time. It may well go back before anatomically modern humans. I say that because of the greater honeyguide, which guides people to beehives in Africa. After we take the honey, the honeyguide eats the grubs and wax. A guiding bird attracts your attention with wavering, chattering ‘tya’ notes compounded with peeps and pipes. It flies towards an occupied hive and then stops and calls again. It has only been seen to guide humans.

I would not be surprised to find that this symbiotic relationship is far older than the the domestication of dogs. But it is not domestication: we certainly don’t control their reproduction. I wouldn’t count on it, but if you could determine the genetic basis of this signaling behavior, you might be able to get an idea of how old it is.

Honeyguides may be mankind’s oldest buds, but they’re nasty little creatures: brood parasites, like cuckoos.
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december 2017 by nhaliday
New Theory Cracks Open the Black Box of Deep Learning | Quanta Magazine
A new idea called the “information bottleneck” is helping to explain the puzzling success of today’s artificial-intelligence algorithms — and might also explain how human brains learn.

sounds like he's just talking about autoencoders?
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september 2017 by nhaliday
Does your weight change between the poles and the equator? (Intermediate) - Curious About Astronomy? Ask an Astronomer
You are right, that because of centrifugal force you will weigh a tiny amount less at the Equator than at the poles. Try not to think of centrifugal force as a force though; what's really going on is that objects which are in motion like to go in a straight line and so it takes some force to make them go round in a circle. (Centrifugal force is a fictitious force that shows up in the equations of motion for an object in a rotating reference frame - such as on Earth's Equator.)

So some of the force of gravity (centripetal force) is being used to make you go around in a circle at the Equator (instead of flying off into space) while at the pole this is not needed. The centripetal acceleration at the Equator is given by four times pi squared times the radius of the Earth divided by the period of rotation squared (4×π2×R/T2). Earth's period of rotation is a sidereal day (86164.1 seconds, slightly less than 24 hours), and the equatorial radius of the Earth is about 6378 km. This means that the centripetal acceleration at the Equator is about 0.03 m/s2 (metres per second squared). Compare this to the acceleration due to gravity which is about 9.8 m/s2 and you can see how tiny an effect this is - you would weigh about 0.3% less at the equator than at the poles!

There is an additional effect due to the oblateness of the Earth. The Earth is not exactly spherical but rather is a little bit like a "squashed" sphere (technically, an oblate spheroid), with the radius at the Equator slightly larger than the radius at the poles. (This shape can be explained by the effect of centrifugal acceleration on the material that makes up the Earth, exactly as described above.) This has the effect of slightly increasing your weight at the poles (since you are close to the centre of the Earth and the gravitational force depends on distance) and slightly decreasing it at the equator.

Taking into account both of the above effects, the gravitational acceleration is 9.78 m/s2 at the equator and 9.83 m/s2 at the poles, so you weigh about 0.5% more at the poles than at the equator.
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september 2017 by nhaliday
GALILEO'S STUDIES OF PROJECTILE MOTION
During the Renaissance, the focus, especially in the arts, was on representing as accurately as possible the real world whether on a 2 dimensional surface or a solid such as marble or granite. This required two things. The first was new methods for drawing or painting, e.g., perspective. The second, relevant to this topic, was careful observation.

With the spread of cannon in warfare, the study of projectile motion had taken on greater importance, and now, with more careful observation and more accurate representation, came the realization that projectiles did not move the way Aristotle and his followers had said they did: the path of a projectile did not consist of two consecutive straight line components but was instead a smooth curve. [1]

Now someone needed to come up with a method to determine if there was a special curve a projectile followed. But measuring the path of a projectile was not easy.

Using an inclined plane, Galileo had performed experiments on uniformly accelerated motion, and he now used the same apparatus to study projectile motion. He placed an inclined plane on a table and provided it with a curved piece at the bottom which deflected an inked bronze ball into a horizontal direction. The ball thus accelerated rolled over the table-top with uniform motion and then fell off the edge of the table Where it hit the floor, it left a small mark. The mark allowed the horizontal and vertical distances traveled by the ball to be measured. [2]

By varying the ball's horizontal velocity and vertical drop, Galileo was able to determine that the path of a projectile is parabolic.

https://www.scientificamerican.com/author/stillman-drake/

Galileo's Discovery of the Parabolic Trajectory: http://www.jstor.org/stable/24949756

Galileo's Experimental Confirmation of Horizontal Inertia: Unpublished Manuscripts (Galileo
Gleanings XXII): https://sci-hub.tw/https://www.jstor.org/stable/229718
- Drake Stillman

MORE THAN A DECADE HAS ELAPSED since Thomas Settle published a classic paper in which Galileo's well-known statements about his experiments on inclined planes were completely vindicated.' Settle's paper replied to an earlier attempt by Alexandre Koyre to show that Galileo could not have obtained the results he claimed in his Two New Sciences by actual observations using the equipment there described. The practical ineffectiveness of Settle's painstaking repetition of the experiments in altering the opinion of historians of science is only too evident. Koyre's paper was reprinted years later in book form without so much as a note by the editors concerning Settle's refutation of its thesis.2 And the general literature continues to belittle the role of experiment in Galileo's physics.

More recently James MacLachlan has repeated and confirmed a different experiment reported by Galileo-one which has always seemed highly exaggerated and which was also rejected by Koyre with withering sarcasm.3 In this case, however, it was accuracy of observation rather than precision of experimental data that was in question. Until now, nothing has been produced to demonstrate Galileo's skill in the design and the accurate execution of physical experiment in the modern sense.

Pant of a page of Galileo's unpublished manuscript notes, written late in 7608, corroborating his inertial assumption and leading directly to his discovery of the parabolic trajectory. (Folio 1 16v Vol. 72, MSS Galileiani; courtesy of the Biblioteca Nazionale di Firenze.)

...

(The same skeptical historians, however, believe that to show that Galileo could have used the medieval mean-speed theorem suffices to prove that he did use it, though it is found nowhere in his published or unpublished writings.)

...

Now, it happens that among Galileo's manuscript notes on motion there are many pages that were not published by Favaro, since they contained only calculations or diagrams without attendant propositions or explanations. Some pages that were published had first undergone considerable editing, making it difficult if not impossible to discern their full significance from their printed form. This unpublished material includes at least one group of notes which cannot satisfactorily be accounted for except as representing a series of experiments designed to test a fundamental assumption, which led to a new, important discovery. In these documents precise empirical data are given numerically, comparisons are made with calculated values derived from theory, a source of discrepancy from still another expected result is noted, a new experiment is designed to eliminate this, and further empirical data are recorded. The last-named data, although proving to be beyond Galileo's powers of mathematical analysis at the time, when subjected to modern analysis turn out to be remarkably precise. If this does not represent the experimental process in its fully modern sense, it is hard to imagine what standards historians require to be met.

The discovery of these notes confirms the opinion of earlier historians. They read only Galileo's published works, but did so without a preconceived notion of continuity in the history of ideas. The opinion of our more sophisticated colleagues has its sole support in philosophical interpretations that fit with preconceived views of orderly long-term scientific development. To find manuscript evidence that Galileo was at home in the physics laboratory hardly surprises me. I should find it much more astonishing if, by reasoning alone, working only from fourteenth-century theories and conclusions, he had continued along lines so different from those followed by profound philosophers in earlier centuries. It is to be hoped that, warned by these examples, historians will begin to restore the old cautionary clauses in analogous instances in which scholarly opinions are revised without new evidence, simply to fit historical theories.

In what follows, the newly discovered documents are presented in the context of a hypothetical reconstruction of Galileo's thought.

...

As early as 1590, if we are correct in ascribing Galileo's juvenile De motu to that date, it was his belief that an ideal body resting on an ideal horizontal plane could be set in motion by a force smaller than any previously assigned force, however small. By "horizontal plane" he meant a surface concentric with the earth but which for reasonable distances would be indistinguishable from a level plane. Galileo noted at the time that experiment did not confirm this belief that the body could be set in motion by a vanishingly small force, and he attributed the failure to friction, pressure, the imperfection of material surfaces and spheres, and the departure of level planes from concentricity with the earth.5

It followed from this belief that under ideal conditions the motion so induced would also be perpetual and uniform. Galileo did not mention these consequences until much later, and it is impossible to say just when he perceived them. They are, however, so evident that it is safe to assume that he saw them almost from the start. They constitute a trivial case of the proposition he seems to have been teaching before 1607-that a mover is required to start motion, but that absence of resistance is then sufficient to account for its continuation.6

In mid-1604, following some investigations of motions along circular arcs and motions of pendulums, Galileo hit upon the law that in free fall the times elapsed from rest are as the smaller distance is to the mean proportional between two distances fallen.7 This gave him the times-squared law as well as the rule of odd numbers for successive distances and speeds in free fall. During the next few years he worked out a large number of theorems relating to motion along inclined planes, later published in the Two New Sciences. He also arrived at the rule that the speed terminating free fall from rest was double the speed of the fall itself. These theorems survive in manuscript notes of the period 1604-1609. (Work during these years can be identified with virtual certainty by the watermarks in the paper used, as I have explained elsewhere.8)

In the autumn of 1608, after a summer at Florence, Galileo seems to have interested himself in the question whether the actual slowing of a body moving horizontally followed any particular rule. On folio 117i of the manuscripts just mentioned, the numbers 196, 155, 121, 100 are noted along the horizontal line near the middle of the page (see Fig. 1). I believe that this was the first entry on this leaf, for reasons that will appear later, and that Galileo placed his grooved plane in the level position and recorded distances traversed in equal times along it. Using a metronome, and rolling a light wooden ball about 4 3/4 inches in diameter along a plane with a groove 1 3/4 inches wide, I obtained similar relations over a distance of 6 feet. The figures obtained vary greatly for balls of different materials and weights and for greatly different initial speeds.9 But it suffices for my present purposes that Galileo could have obtained the figures noted by observing the actual deceleration of a ball along a level plane. It should be noted that the watermark on this leaf is like that on folio 116, to which we shall come presently, and it will be seen later that the two sheets are closely connected in time in other ways as well.

The relatively rapid deceleration is obviously related to the contact of ball and groove. Were the ball to roll right off the end of the plane, all resistance to horizontal motion would be virtually removed. If, then, there were any way to have a given ball leave the plane at different speeds of which the ratios were known, Galileo's old idea that horizontal motion would continue uniformly in the absence of resistance could be put to test. His law of free fall made this possible. The ratios of speeds could be controlled by allowing the ball to fall vertically through known heights, at the ends of which it would be deflected horizontally. Falls through given heights … [more]
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august 2017 by nhaliday
How & Why Solar Eclipses Happen | Solar Eclipse Across America - August 21, 2017
Cosmic Coincidence
The Sun’s diameter is about 400 times that of the Moon. The Sun is also (on average) about 400 times farther away. As a result, the two bodies appear almost exactly the same angular size in the sky — about ½°, roughly half the width of your pinky finger seen at arm's length. This truly remarkable coincidence is what gives us total solar eclipses. If the Moon were slightly smaller or orbited a little farther away from Earth, it would never completely cover the solar disk. If the Moon were a little larger or orbited a bit closer to Earth, it would block much of the solar corona during totality, and eclipses wouldn’t be nearly as spectacular.

https://blogs.scientificamerican.com/life-unbounded/the-solar-eclipse-coincidence/
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august 2017 by nhaliday
How large is the Sun compared to Earth? | Cool Cosmos
Compared to Earth, the Sun is enormous! It contains 99.86% of all of the mass of the entire Solar System. The Sun is 864,400 miles (1,391,000 kilometers) across. This is about 109 times the diameter of Earth. The Sun weighs about 333,000 times as much as Earth. It is so large that about 1,300,000 planet Earths can fit inside of it. Earth is about the size of an average sunspot!
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august 2017 by nhaliday
Controversial New Theory Suggests Life Wasn't a Fluke of Biology—It Was Physics | WIRED
First Support for a Physics Theory of Life: https://www.quantamagazine.org/first-support-for-a-physics-theory-of-life-20170726/
Take chemistry, add energy, get life. The first tests of Jeremy England’s provocative origin-of-life hypothesis are in, and they appear to show how order can arise from nothing.
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august 2017 by nhaliday
Correlated Equilibria in Game Theory | Azimuth
Given this, it’s not surprising that Nash equilibria can be hard to find. Last September a paper came out making this precise, in a strong way:

• Yakov Babichenko and Aviad Rubinstein, Communication complexity of approximate Nash equilibria.

The authors show there’s no guaranteed method for players to find even an approximate Nash equilibrium unless they tell each other almost everything about their preferences. This makes finding the Nash equilibrium prohibitively difficult to find when there are lots of players… in general. There are particular games where it’s not difficult, and that makes these games important: for example, if you’re trying to run a government well. (A laughable notion these days, but still one can hope.)

Klarreich’s article in Quanta gives a nice readable account of this work and also a more practical alternative to the concept of Nash equilibrium. It’s called a ‘correlated equilibrium’, and it was invented by the mathematician Robert Aumann in 1974. You can see an attempt to define it here:
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july 2017 by nhaliday
The Greatest Generation | West Hunter
But  when you consider that people must have had 48 chromosomes back then, rather than the current measly 46, much is explained.

Theophilus Painter, a prominent cytologist, had investigated human chromosome number in 1923. He thought that there were 24 in sperm cells, resulting in a count of 48, which is entirely reasonable. That is definitely the case for all our closest relatives (chimpanzees, bonobos, gorillas, and orangutans).

The authorities say that that Painter made a mistake, and that humans always had 46 chromosomes. But then, for 30 years after Painter’s work, the authorities said that people had 48.  Textbooks in genetics continued to say that Man has 48 chromosomes up until the mid 1950s.  Many cytologists and geneticists studied human chromosomes during that period, but they knew that there were 48, and that’s what they saw. Now they know that there are 46, and that’s what every student sees.

Either the authorities are fallible and most people are sheep, or human chromosome number actually changed sometime after World War II.  No one could believe the first alternative: it would hurt our feelings, and therefore cannot be true.  No, we have a fascinating result: people today are fundamentally different from the Greatest Generation, biologically different: we’re two chromosomes shy of a load. .    So it’s not our fault !

http://blogs.discovermagazine.com/loom/2012/07/19/the-mystery-of-the-missing-chromosome-with-a-special-guest-appearance-from-facebook-creationists/

funny comment: https://westhunt.wordpress.com/2014/11/19/the-greatest-generation/#comment-62920
“some social environments are better than others at extracting the best from its people”

That’s very true – we certainly don’t seem to be doing a very good job of it. It’s a minor matter, but threatening brilliant engineers with death or professional ruin because of their sexist sartorial choices probably isn’t helping…

I used to do some engineering, and if someone had tried on that on me, I’ve have told him to go fuck itself. Is that a lost art?

https://www.theguardian.com/science/2014/nov/14/rosetta-comet-dr-matt-taylor-apology-sexist-shirt
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july 2017 by nhaliday
Electroconvulsive therapy: a crude, controversial out-of-favor treatme – Coyne of the Realm
various evidence that ECT works

I will soon be offering e-books providing skeptical looks at mindfulness and positive psychology, as well as scientific writing courses on the web as I have been doing face-to-face for almost a decade.

https://www.coyneoftherealm.com/collections/frontpage

Coyne of the Realm Takes a Skeptical Look at Mindfulness — Table of Contents: https://www.coyneoftherealm.com/pages/coyne-of-the-realm-takes-a-skeptical-look-at-mindfulness-table-of-contents

Mind the Hype: A Critical Evaluation and Prescriptive Agenda for Research on Mindfulness and Meditation: http://journals.sagepub.com/doi/10.1177/1745691617709589
Where's the Proof That Mindfulness Meditation Works?: https://www.scientificamerican.com/article/wheres-the-proof-that-mindfulness-meditation-works1/
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june 2017 by nhaliday
Secular decline in testosterone levels - Rogue Health and Fitness
A Population-Level Decline in Serum Testosterone Levels in American Men: http://sci-hub.tw/10.1210/jc.2006-1375
Secular trends in sex hormones and fractures in men and women: http://www.eje-online.org/content/166/5/887.full.pdf
https://twitter.com/toad_spotted/status/984543033285898246
https://archive.is/dcruu
Small n and older sample, but interesting that while testosterone decreases have been large for men they’ve been even larger (in % terms) for women; wonder if this contributes to declining pregnancy and sexual frequency, rising depression.

https://www.labcorp.com/assets/11476
http://www.theamericanconservative.com/articles/sperm-killers-and-rising-male-infertility/
https://www.theguardian.com/lifeandstyle/2017/jul/25/sperm-counts-among-western-men-have-halved-in-last-40-years-study
https://www.weforum.org/agenda/2017/08/most-men-in-the-us-and-europe-could-be-infertile-by-2060
Strangelove: https://youtu.be/N1KvgtEnABY?t=67

https://www.scientificamerican.com/article/sperm-count-dropping-in-western-world/
https://news.ycombinator.com/item?id=14855796
https://news.ycombinator.com/item?id=14857588
People offering human-centric explanations like cell phones: Note also that the sperm quality of dogs has decreased 30% since 1988.

https://www.cbc.ca/radio/quirks/august-3-2019-science-of-awe-blue-whales-and-sonar-chromosomes-and-sleep-and-more-1.5047142/man-and-man-s-best-friend-have-both-been-experiencing-declines-in-sperm-quality-1.5047150
https://news.ycombinator.com/item?id=20636757

mendelian rand.:
https://www.ncbi.nlm.nih.gov/pubmed/28448539
1 SD genetically instrumented increase in BMI was associated with a 0.25 SD decrease in serum testosterone
https://twitter.com/SilverVVulpes/status/857902555489341441

Ibuprofen linked to male infertility: study: https://nypost.com/2018/01/08/ibuprofen-linked-to-male-infertility-study/
http://www.pnas.org/content/115/4/E715.full

Tucker Carlson: "Men Seem To Be Becoming Less Male": https://www.realclearpolitics.com/video/2018/03/08/tucker_carlson_men_seem_to_be_becoming_less_male.html
Carlson interviewed Dr. Jordan Peterson who blamed the "insidious" movement being driven by the "radical left" that teaches there a problem of "toxic masculinity." He said ideological policies focus on "de-emphasizing masculinity may be part of the problem."

...

Those are the numbers. They paint a very clear picture: American men are failing, in body, mind and spirit. This is a crisis. Yet our leaders pretend it’s not happening. They tell us the opposite is true: Women are victims, men are oppressors. To question that assumption is to risk punishment. Even as women far outpace men in higher education, virtually every college campus supports a women’s studies department, whose core goal is to attack male power. Our politicians and business leaders internalize and amplify that message. Men are privileged. Women are oppressed. Hire and promote and reward accordingly.

https://pinboard.in/u:nhaliday/b:bd7b0a50d741
But it also hints at an almost opposite take: average testosterone levels have been falling for decades, so at this point these businessmen would be the only “normal” (by 1950s standards) men out there, and everyone else would be unprecedently risk-averse and boring.
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may 2017 by nhaliday
Peter Ungar, the Author of 'Evolution's Bite,' on Teeth History - The Atlantic
Ungar: The conventional wisdom in bioarchaeology is that the onset of agriculture and the increase in carbohydrate consumption led to more cavities. These carbohydrates—and especially later on when we hit the Industrial Revolution and the wide availability of refined sugars—provide a bed to which the bacteria that cause cavities can stick. They provide food for the bacteria as well. These microorganisms they eat, then they reproduce, and they poop. And it’s that poop basically that is acidic and erodes the teeth and causes cavities.

There’s certainly some evidence in a lot of the world where that’s the case, particularly the New World where people started to consume a lot of maize, a lot of corn. The cavities rate went way up with corn consumption. But we really don’t see it that much in, say,  the Middle East where people started to eat wheat and barley. And even less in Far East where people started to consume rice. That leaves a complicating factor.
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april 2017 by nhaliday
Octopuses Do Something Really Strange to Their Genes - The Atlantic
But to what end? RNA editing is still mysterious, and its purpose unclear. Technically, an animal could use it to change the nature of its proteins without altering the underlying DNA instructions. But in practice, this kind of recoding is extremely rare. Only about 3 percent of human genes are ever edited in this way, and the changes are usually restricted to the parts of RNA that are cut out and discarded. To the extent that it happens, it doesn’t seem to be adaptive.

In cephalopods, it’s a different story. Back in 2015, Rosenthal and Eisenberg discovered that RNA editing has gone wild in the longfin inshore squid—a foot-long animal that’s commonly used in neuroscience research. While a typical mammal edits its RNA at just a few hundred sites, the squid was making some 57,000 such edits. These changes weren’t happening in discarded sections of RNA, but in the ones that actually go towards building proteins—the so-called coding regions. They were ten times more common in the squid’s neurons than in its other tissues, and they disproportionately affected proteins involved in its nervous system.
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april 2017 by nhaliday
Extended spider cognition | SpringerLink
Spiders do not seem to be cognitively limited, displaying a large diversity of learning processes, from habituation to contextual learning, including a sense of numerosity. To tease apart the central from the extended cognition, we apply the mutual manipulability criterion, testing the existence of reciprocal causal links between the putative elements of the system. We conclude that the web threads and configurations are integral parts of the cognitive systems. The extension of cognition to the web helps to explain some puzzling features of spider behaviour and seems to promote evolvability within the group, enhancing innovation through cognitive connectivity to variable habitat features. Graded changes in relative brain size could also be explained by outsourcing information processing to environmental features. More generally, niche-constructed structures emerge as prime candidates for extending animal cognition, generating the selective pressures that help to shape the evolving cognitive system.

https://www.quantamagazine.org/the-thoughts-of-a-spiderweb-20170523/
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april 2017 by nhaliday
How Humans Evolved Supersize Brains | Quanta Magazine
Based on her studies, Herculano-Houzel has concluded that primates evolved a way to pack far more neurons into the cerebral cortex than other mammals did. The great apes are tiny compared to elephants and whales, yet their cortices are far denser: Orangutans and gorillas have 9 billion cortical neurons, and chimps have 6 billion. Of all the great apes, we have the largest brains, so we come out on top with our 16 billion neurons in the cortex. In fact, humans appear to have the most cortical neurons of any species on Earth. “That’s the clearest difference between human and nonhuman brains,” Herculano-Houzel says. It’s all about the architecture, not just size.
news  org:mag  org:sci  popsci  evolution  sapiens  neuro  eden  density  comparison  nature  data  scale  nibble  org:inst 
march 2017 by nhaliday
Was the Wealth of Nations Determined in 1000 BC?
Our most interesting, strong, and robust results are for the association of 1500 AD technology with per capita income and technology adoption today. We also find robust and significant technological persistence from 1000 BC to 0 AD, and from 0 AD to 1500 AD.

migration-adjusted ancestry predicts current economic growth and technology adoption today

https://economix.blogs.nytimes.com/2010/08/02/was-todays-poverty-determined-in-1000-b-c/

Putterman-Weil:
Post-1500 Population Flows and the Long Run Determinants of Economic Growth and Inequality: http://www.nber.org/papers/w14448
Persistence of Fortune: Accounting for Population Movements, There Was No Post-Columbian Reversal: http://sci-hub.tw/10.1257/mac.6.3.1
Extended State History Index: https://sites.google.com/site/econolaols/extended-state-history-index
Description:
The data set extends and replaces previous versions of the State Antiquity Index (originally created by Bockstette, Chanda and Putterman, 2002). The updated data extends the previous Statehist data into the years before 1 CE, to the first states in Mesopotamia (in the fourth millennium BCE), along with filling in the years 1951 – 2000 CE that were left out of past versions of the Statehist data.
The construction of the index follows the principles developed by Bockstette et al (2002). First, the duration of state existence is established for each territory defined by modern-day country borders. Second, this duration is divided into 50-year periods. For each half-century from the first period (state emergence) onwards, the authors assign scores to reflect three dimensions of state presence, based on the following questions: 1) Is there a government above the tribal level? 2) Is this government foreign or locally based? 3) How much of the territory of the modern country was ruled by this government?

Creators: Oana Borcan, Ola Olsson & Louis Putterman

State History and Economic Development: Evidence from Six Millennia∗: https://drive.google.com/file/d/1cifUljlPpoURL7VPOQRGF5q9H6zgVFXe/view
The presence of a state is one of the most reliable historical predictors of social and economic development. In this article, we complete the coding of an extant indicator of state presence from 3500 BCE forward for almost all but the smallest countries of the world today. We outline a theoretical framework where accumulated state experience increases aggregate productivity in individual countries but where newer or relatively inexperienced states can reach a higher productivity maximum by learning from the experience of older states. The predicted pattern of comparative development is tested in an empirical analysis where we introduce our extended state history variable. Our key finding is that the current level of economic development across countries has a hump-shaped relationship with accumulated state history.

nonlinearity confirmed in this other paper:
State and Development: A Historical Study of Europe from 0 AD to 2000 AD: https://ideas.repec.org/p/hic/wpaper/219.html
After addressing conceptual and practical concerns on its construction, we present a measure of the mean duration of state rule that is aimed at resolving some of these issues. We then present our findings on the relationship between our measure and local development, drawing from observations in Europe spanning from 0 AD to 2000 AD. We find that during this period, the mean duration of state rule and the local income level have a nonlinear, inverse U-shaped relationship, controlling for a set of historical, geographic and socioeconomic factors. Regions that have historically experienced short or long duration of state rule on average lag behind in their local wealth today, while those that have experienced medium-duration state rule on average fare better.

Figure 1 shows all borders that existed during this period
Figure 4 shows quadratic fit

I wonder if U-shape is due to Ibn Kaldun-Turchin style effect on asabiya? They suggest sunk costs and ossified institutions.
study  economics  growth-econ  history  antiquity  medieval  cliometrics  macro  path-dependence  hive-mind  garett-jones  spearhead  biodet  🎩  🌞  human-capital  divergence  multi  roots  demographics  the-great-west-whale  europe  china  asia  technology  easterly  definite-planning  big-picture  big-peeps  early-modern  stylized-facts  s:*  broad-econ  track-record  migration  assimilation  chart  frontier  prepping  discovery  biophysical-econ  cultural-dynamics  wealth-of-nations  ideas  occident  microfoundations  news  org:rec  popsci  age-of-discovery  expansionism  conquest-empire  pdf  piracy  world  developing-world  deep-materialism  dataset  time  data  database  time-series  leviathan  political-econ  polisci  iron-age  mostly-modern  government  institutions  correlation  curvature  econ-metrics  wealth  geography  walls  within-group  nonlinearity  convexity-curvature  models  marginal  wire-guided  branches  cohesion  organizing  hari-seldon 
march 2017 by nhaliday
A Unified Theory of Randomness | Quanta Magazine
Beyond the one-dimensional random walk, there are many other kinds of random shapes. There are varieties of random paths, random two-dimensional surfaces, random growth models that approximate, for example, the way a lichen spreads on a rock. All of these shapes emerge naturally in the physical world, yet until recently they’ve existed beyond the boundaries of rigorous mathematical thought. Given a large collection of random paths or random two-dimensional shapes, mathematicians would have been at a loss to say much about what these random objects shared in common.

Yet in work over the past few years, Sheffield and his frequent collaborator, Jason Miller, a professor at the University of Cambridge, have shown that these random shapes can be categorized into various classes, that these classes have distinct properties of their own, and that some kinds of random objects have surprisingly clear connections with other kinds of random objects. Their work forms the beginning of a unified theory of geometric randomness.
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february 2017 by nhaliday
How do food manufacturers calculate the calorie count of packaged foods? - Scientific American
The original method used to determine the number of kcals in a given food directly measured the energy it produced.The food was placed in a sealed container surrounded by water--an apparatus known as a bomb calorimeter. The food was completely burned and the resulting rise in water temperature was measured. This method is not frequently used today.
q-n-a  news  org:sci  popsci  food  nutrition  measurement  phys-energy  physics  thermo  org:mag  explanation  metabolic  methodology  fire  heavy-industry 
february 2017 by nhaliday
INFECTIOUS CAUSATION OF DISEASE: AN EVOLUTIONARY PERSPECTIVE
A New Germ Theory: https://www.theatlantic.com/magazine/archive/1999/02/a-new-germ-theory/377430/
The dictates of evolution virtually demand that the causes of some of humanity's chronic and most baffling "noninfectious" illnesses will turn out to be pathogens -- that is the radical view of a prominent evolutionary biologist

A LATE-SEPTEMBER heat wave enveloped Amherst College, and young people milled about in shorts or sleeveless summer frocks, or read books on the grass. Inside the red-brick buildings framing the leafy quadrangle students listened to lectures on Ellison and Emerson, on Paul Verlaine and the Holy Roman Empire. Few suspected that strains of the organism that causes cholera were growing nearby, in the Life Sciences Building. If they had known, they would probably not have grasped the implications. But these particular strains of cholera make Paul Ewald smile; they are strong evidence that he is on the right track. Knowing the rules of evolutionary biology, he believes, can change the course of infectious disease.

https://www.theatlantic.com/past/docs/issues/99feb/germ2.htm
I HAVE a motto," Gregory Cochran told me recently. "'Big old diseases are infectious.' If it's common, higher than one in a thousand, I get suspicious. And if it's old, if it has been around for a while, I get suspicious."

https://www.theatlantic.com/past/docs/issues/99feb/germ3.htm
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february 2017 by nhaliday
In Computers We Trust? | Quanta Magazine
As math grows ever more complex, will computers reign?

Shalosh B. Ekhad is a computer. Or, rather, it is any of a rotating cast of computers used by the mathematician Doron Zeilberger, from the Dell in his New Jersey office to a supercomputer whose services he occasionally enlists in Austria. The name — Hebrew for “three B one” — refers to the AT&T 3B1, Ekhad’s earliest incarnation.

“The soul is the software,” said Zeilberger, who writes his own code using a popular math programming tool called Maple.
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january 2017 by nhaliday
Why Chinese Speakers Cut Their Hair Before New Year’s
Is the Chinese Language a Superstition Machine?: How ambiguity in language can create unique taboos.
news  org:mag  popsci  china  asia  language  culture  biases  cocktail  org:sci  foreign-lang  sinosphere  embedded-cognition  info-dynamics 
january 2017 by nhaliday
Tibetan Plateau Discovery Shows Humans May Be Tougher Than We Thought - Scientific American
The first humans venturing onto the Tibetan Plateau, often called the “roof of the world,” faced one of the most brutal environments our species can endure. At an average elevation of over 4,500 meters, it is a cold and arid place with half the oxygen present at sea level. Science has long held that humans did not set foot in this alien place until 15,000 years ago, as suggested by archaeological evidence of the earliest known settlement on the northeastern fringe of the plateau 3,000 meters above sea level. But now new genetic data indicate this may have occurred much earlier—possibly as far back as the last ice age, 62,000 years ago.
news  org:mag  popsci  sapiens  asia  antiquity  genetics  world  environment  org:sci  archaics 
december 2016 by nhaliday
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