Saturday, December 16, 2017

Net Neutrality

Ever since the FCC repealed net neutrality my internet speeds have declined to glacial rates - sometimes too slow to even run an internet speed test.

Coincidence? Maybe. But these are paranoid times.

Wednesday, December 13, 2017

Are Blockchains Vulnerable

Lumo is talking about the possibility of something called a 51% attack on blockchains. I don't know enough to have an opinion, but I would be interested in the opinions of those who do.

Alabama Does The Right Thing

Dems are celebrating a big win in the Alabama Senate race, but it's way too early to start patting themselves on the back. It took an exceptional alignment of the stars for Doug Jones to win and such circumstances are unlikely to repeat: the sexual predator accusations, the fact that Moore was already unpopular in Alabama, and the hostility of the mainstream Republican party.

The old line Repubs are celebrating another ding in Steve Bannon, but there is plenty of evidence that Trump and Bannon still speak for a big chunk of the electorate. I think Dems will need to further erode that support if they are going to get to majority status in Congress.

Saturday, December 09, 2017

Forming Planets

In the current universe, stars form in large molecular clouds, usually having masses thousands of times that of the Sun. Consequently, they usually form in clusters of hundreds or thousands of stars. The discovery of thousands of extra-solar planets in the last couple of decades has demonstrated that many of these stars have planets. So how do these planets form?

The molecular clouds out of which stars form are turbulent, and consequently the blobs that condense to form stars have angular momentum - quite a bit more angular momentum than a star, and more, in fact, than a typical stellar system with planets. One way to deal with the angular momentum is to form a binary or multi-star system, two or more stars orbiting each other, and this is extremely common. Another way is to produce a planetary system, and for our solar system, most of the angular momentum is in the planets - mostly in Jupiter.

When a overdense "core" region of a cloud stars contracting under gravity, the angular momentum means that a significant fraction of the mass will form a disk perpendicular to the angular momentum vector (or, if you prefer, in the plane of the angular momentum bi-vector). This disk is flattened by gravity and viscosity, and its angular momentum resists being sucked into the star.

Our solar system seems kind of neat and simple. The planets close to the Sun are either metallic like Mercury or stony and metallic like Venus, Earth, and Mars, while out beyond the "snow line" where ices could condense, we have the gas giants Jupiter and Saturn and the ice giants Uranus and Neptune. Everything in its place so to speak.

The discovery of exoplanets revealed that the Universe is not that simple. There are hot Jupiters and Neptunes orbiting their stars far closer than Mercury, where they couldn't possibly have formed. Unravelling puzzles like this is one reason planetary formation science is now one of the hottest topics in Astrophysics. It's a good subject for generalists, requiring a mix of dynamics, thermodynamics and radiative transport, geology, chemistry, and stellar physics.

Friday, December 08, 2017

All Your Base Are Belong to Us

First they came, for Checkers, but I was silent, because I played chess. Then they came for chess, so I might have been a bit less silent, but hey, I still played Go. I whined when Go went down, but now, goldarn it, Alpha Zero has bested the strongest computer programs in Chess, Shogi, and Go, starting from scratch in each case (just the rules) and training itself solely by self-play, making zzero use of all the information humans have assembled over thousands of years of play. Even more annoyingly, it took only a few days to do it. Via Steve Hsu.

It's somewhat analogous to giving a five year old a chess set, explaining the rules to him, and coming back a few days later to find he was far better than the best player in the world. Clearly the best neural networks can now learn far more rapidly, and understand more deeply, than any human, at least in narrow domains.

All these games are narrowly constrained by definite rules and very specific outcomes. In most human activities we either have no definite rules or don't know the rules, so the strategies of Alpha Zero are not directly applicable. One domain where the rules are pretty definite is math. There have been a few situations where computers have been able to prove specific theorems of interest to humans, but I wonder if anybody has given a neural network like Alpha Zero the very simple axioms of say, group theory, and asked it to prove all the interesting theorems. An even better trick would be to get it to discover the interesting theorems.

Once More Into the Breach...

A few years ago, scientists managed to extract some DNA from 5000 year old bones at an ancient burial site at Rakhigarhi, now a village in India, but formerly one of the great cities of the Indus Valley Civilization (IVC), an ancient and mysterious civilization. One reason the civilization is so mysterious is that its writings, which consist only of a few short inscriptions, have never been deciphered, nor is it known if they even are actually writings.

That DNA is very interesting to students of India's demographic history, because it could shed light on a famous controversy over the origins of the Indo-European (IE) languages of India, and consequently on the history of Indian culture, religion and its great literature. Modern Hinduism is thought to have its origins in the Vedas, which were carefully preserved in an elaborate oral tradition for at least hundreds of years and only written down around the First Century BCE. The language of the Vedas is Vedic Sanskrit, an Indo-European language.

There are a few theories of the origin of the IE languages, the most prominent being that it arose in horse domesticating, cart riding pastoralists of the Eurasian steppe near the Black Sea. There is ample genetic and linguistic evidence that these peoples swept across the steppe and across Europe, conquering and wiping out nearly all previous languages. A corollary is that they also invaded India, either at or shortly after the collapse of the IVC.

Hindu nationalists as well as some scholars prefer an Out of India theory of IE origins. The Hindu nationalist semi-official mythology believes that Vedic culture survives from the IVC and therefore that Hindu Civilization is autochthonous, and are offended by the idea that Vedic culture might be due to invaders. Contemporary genetic evidence indicates that most current Indians are mixtures of two genetic strains, the so-called Ancestral South Indians (ASI) who have no close links with any other genetic group except Andaman Islanders and Ancestral North Indians, who are closely related to Northern Eurasians and ancient Iranian farmers.

The Aryan Invasion Theory, and its slightly more PC version, the Aryan Migration Theory, posit that the IE languages (and consequently, parts of the Vedic culture) were brought to India by invaders (or migrants) to India after the decline of the IVC. Consequently, the DNA from Rakhigarhi might provide crucial evidence. If that DNA looks just like modern Indian DNA, then the origin of Vedic culture in the IVC gains a lot of credibility. On the other hand, if it looks either like ASI DNA, or a mixture of ASI and ancient Iranian farmer DNA, the Aryan incursion theories look more plausible.

Now to the chase: we have been promised the results for well over a year now, but none have been produced. The non-Indian experts who did the analysis have said that the results are in the hands of their Indian co-author. From him, silence.

If you have any bit of paranoia you should now be convinced that (a) the results are not favorable to the Hindu Nationalist mythology and (b) are being suppressed for political reasons.

Note that political reasons may not be bad reasons. Hindu Nationalists have displayed a nasty violent streak, and those who fail to toe the line may be persecuted or even lynched, often on the basis of unconfirmed or baseless rumors.

Thursday, December 07, 2017

Winter Comes...

...to Las Cruces, but it's having a lot of trouble getting here. It's snowing right now to the North, West, and East of us. It's even snowing South of us, in El Paso and Mexico. But here, the Sun is shining.

I mean if it's going to be cold anyway, could we at least get some snow?

WTF?

Here is the accusation which supposedly is bringing down Al Franken:

Dupuy said she “saw Al Franken” and asked to take a picture with him because her foster mother was a fan. “We posed for the shot. He immediately put his hand on my waist, grabbing a handful of flesh. I froze. Then he squeezed. At least twice,” Dupuy said.

Sunday, December 03, 2017

Men (Still) Behaving Badly

Powerful men continue to fall in the wake of Harvey Weinstein's tumble. I doubt if it is news to many women that there are a lot of predators out there, but it keeps surprising men, including the perps, many of whom seem shocked to learn that their behavior was reprehensible. Of course that could be feigned, but I don't think all of it is. One would hope that the steady demolition of icons would cause predators to change their behavior, but it's probably way too early to tell.

I was watching a morning news show in which several women discussed a bunch of highly influential newsmen among the recently fallen, and the role they may have played in Hillary Clinton's defeat. The argument was that their predatory behavior was linked to pervasive disrespect for women, and that disrespect was reflected in the coverage of Clinton. I found their arguments pretty persuasive, but I also have to confess that whenever the camera focussed on the youngest one, my primitive brain could not resist announcing to me that "Damn, she's hot!"

So what's the cure, or is there a cure? Most cultures have considered the issue and concluded that men are inherently so dangerous that women need to be kept locked up, one way or another. Oddly enough, many women don't like this idea. An idea popular with the panelists was that more women in power would discourage male predatory behavior, and I think that that sounds reasonable, but I also guess that the predatory instinct is deeply embedded.

I recall somebody, perhaps Jared Diamond, writing about young chimpanzees but with an eye to their cousins, that the males competed obsessively for status, first dominating younger conspecifics, then females, and finally other adult males. It's not a purely male problem, as among humans, as well as our hairier relatives, females are attracted to those dominating males.

White women in Alabama are mostly planning to vote for Moore.

Friday, December 01, 2017

Interesting Headline:

New York City Has Genetically Distinct ‘Uptown’ and ‘Downtown’ Rats.

But then I found out that the story was about rodents.