Tuesday, April 25, 2017

Open Clusters: Three Body Problems

All stars seem to form from large molecular clouds, and each such formation event seems to produce many stars - hundreds or thousands. Many of these clouds quickly disperse, but so-called open clusters can endure for billions of years. They do exhibit a peculiar behavior though. Instead of the expected behavior, called dynamical relaxation, in which the heaviest stars sink gradually toward the center while the lighter ones expand they seem to show a very gradual uniform expansion. It appears that this is due to interactions of other stars with binaries pairs of stars. (A SciAm article by Steven W. Stahler)

What drives the uniform expansion of open clusters? Converse and I demonstrated that the key is binary stars: pairs of close, orbiting companions that are quite common in stellar groups. Simulations performed by Douglas Heggie, now at the University of Edinburgh in Scotland, showed in the mid-1970s that when a third star approaches such a pair, the three engage in a complicated dance, after which the lightest of the three is usually ejected at high speed. The ejected star soon encounters other members and shares its energy with them, increasing those stars’ orbital velocities and e!ectively “heating up” the cluster. In our N-body simulations, it was the energy from these binary encounters that caused the open cluster to expand— albeit so slowly that the expansion could easily go unnoticed by astronomers.

The article is interesting throughout, with the usual good Scientific American figures and charts.

Monday, April 24, 2017

Amazon Knows My Taste

Wherever I go on the Web, Amazon ads follow me. And not random adverts. Ones carefully tailored to my taste. As proven by the fact that I have already bought those books. From Amazon.

How dumb do they think I am? Or do they actually know?

Sunday, April 23, 2017


In my gender and skin color. Let me rephrase that: I'm perfectly happy being male and having the skin color I have, despite its probable contribution to my skin cancers. What I'm unhappy with is that small majorities of both whites and males still approve Trump more than they disapprove him. So, at least, says a new Washington Post CNN poll. I had sort of reconciled to being a member of the mentally weaker sex, but skin color too?

I mean, fellow males and pale skins, WTF is the matter with us? This is not a hard question. Hope you wake up before this idiot gets us all killed.

Gunning for the Win

You really can't afford to be anti-gun in Montana. How the candidates for Montana's open Congressional seat show their arms:

Since then, Quist has vowed to protect Second Amendment rights. In his gun ad, he uses his family’s rifle to shoot a TV playing an attack ad.

Gianforte countered that with an ad of his own, claiming that Quist wants to create a national gun registry that would store personal information on a “big government computer.” The ad then shows Gianforte using a firearm to shatter a computer screen.


History's Lessons

...are many but highly ambiguous. Some historians would even deny their existence.

History Does Not Repeat Itself, But It Rhymes.............attributed to, but quite possibly not actually said by, Mark Twain.

One lesson I'm pretty confident of, however, is that humans have a strong tendency to assemble themselves in rival groups and kill each other. My confidence is considerably increased by the collaborating evidence from anthropology, archaeology, biology, and psychology. That tendency has always been a source of endless grief, but since the advent of nuclear weapons, has become an extinction level threat.

Historically, the best remedy for interpersonal violence has been a state with a monopoly on violence. Only a global state, or something like it, could work when every two-bit state gets nuclear weapons. Such a state is unnatural to human instincts, and anathema to nationalists of every stripe, so highly unlikely to happen. Unless our robot overlords decide that it's necessary.


World War II shattered every great power except the US and Russia. When Germany surrendered, the Soviets had overwhelming military superiority in Europe. Had Stalin chosen that moment to try to overrun the rest of Europe, could he have been stopped? It's hard to imagine how. The much smaller US Army in Europe would have been hard pressed to stop them.

Stalin already knew, though, that the US was close to a nuclear bomb - the Trinity test was only two months away, and after Hiroshima, it was clear that that option was impossible.

I seem to recall that Bertrand Russell suggested that it would be a good idea for the US and Britain to use their nuclear superiority at that point to force Russia to surrender and give up it's plans for a bomb. Many of the scientists at Los Alamos foresaw the world of today, where all sorts of countries would have nukes and the means to deliver them, and thought that the only viable alternative was global control.

Today we are on the brink of a world where dozens* of countries, some led by madmen, have nuclear weapons and the means to deliver them globally.

*The list today likely includes the US, Britain, France, Russia, China (the five official nuclear weapons states), India and Israel. Pakistan and North Korea also have bombs, but likely still lack the means to deliver them globally. Iran is probably not far behind. South Africa formerly had the bomb, and today essentially every technologically advanced state could build them rather quickly. It cost the US about 2 billion dollars to make the first bombs (perhaps 20-30 billion in today's dollars), but today it would be far, far cheaper.

Le Pen vs. Macron

With about 1/3 of the vote counted.

That's not the worst possible outcome.

Navel Gazing

My curiosity was aroused when I noticed that a couple of so called referring URLs were from the Rational Wiki's Luboš Motl Page. I couldn't find any reference to my blog on the page, so I'm a bit curious as to how I could have been referred from it. It's true that I'm a long time student of the Lumonator, and that I have been known to refer to him as "the blogfather," since he is really my inspiration (or provocation) for blogging, but that's not much help.

UPDATE: Never mind. My reading skills obviously are lacking. Also, I noticed that someone, (Lumo?) had "edited" the title of my blog. I thought that I might try to edit it, but the signing up puzzle defeated my senile intellect.

Eve of Destruction

Richard Feynman, who had driven his roommate Klaus Fuchs’s old Buick down to Albuquerque the previous June, in the midst of the final effort to finish the bombs, to keep vigil with his young wife Arlene while she died of tuberculosis, found himself lost between worlds. Before he left Los Alamos he had thought about what the bomb meant and had made some notes. He had calculated that Little Boys in mass production would cost about as much as B-29s. “No monopoly,” he had written.863 “No defense.” And: “No security until we have control on a world level. . . . Other peoples are not being hindered in the development of the bomb by any secrets we are keeping. . . . Soon they will be able to do to Columbus, Ohio, and hundreds of cities like it what we did to Hiroshima. And we scientists are clever—too clever—are you not satisfied? Is four square miles in one bomb not enough? Men are still thinking. Just tell us how big you want it!” The twenty-six-year-old widower may have seen too much of death. He sat in a bar in Manhattan one afternoon in the months after the war looking out the window at all the people going by and shaking his head, thinking how sad it was that they didn’t realize they had only a few years to live.

Rhodes, Richard. Dark Sun: The Making Of The Hydrogen Bomb (p. 202). Simon & Schuster. Kindle Edition.

The world has avoided nuclear destruction for 70 some years through deterrence. Now it looks like nuclear weapons and the means to deliver them are falling into the hands of religious fanatics and dangerously homicidal dictators. How long can this unstable equilibrium last? Not only that, but the leaders of two of the world's three nuclear superpowers are aggressive and far from intelligent.

Saturday, April 22, 2017

Oh Dear!

Bee explains that physicists haven't really created negative mass.

Next she'll probably be claiming that various athletic feats don't actually defy the laws of physics.

Is nothing sacred?

Defection: Canadian Style

Shortly after the war, a cipher clerk in the Soviet embassy in Canada who had decided to defect, gathered up documents demonstrating the extent and details of Soviet spying and went to a newspaper. He was ignored. Attempts to go to the government were equally unpromising:

Finally the Minister of Justice sent out word that they should go back to the Soviet Embassy and return the documents. The Gouzenkos assumed that Soviet agents within the government must have made so stupid and deadly a decision. In fact, it came directly from the Prime Minister of Canada, Mackenzie King, who seems to have been terrified that he might stir up trouble with the Soviet Union.

Rhodes, Richard. Dark Sun: The Making Of The Hydrogen Bomb (p. 184). Simon & Schuster. Kindle Edition.

Friday, April 21, 2017

Grouchy Review

Veep is a much honored show that has been running on HBO since the Devonian. Having recently acquired access, I caught about one and one half episodes before concluding that it was a)really dumb, b)not funny.

Of course if I get bored enough to watch any more I might change my mind. Anybody got a contrary?

Secrets and Spies

Several early chapters of Dark Sun are devoted to Soviet spies in the US Manhattan project and their influence on the Russian bomb effort. It was immense. During the war the US shipped thousands of tanks, aircraft, ships, and even whole factories to Russia to support the war effort against Germany. They also shipped thousands of sealed suitcases, which contained tens of thousands of documents, many of them top secret. A flood of Soviet agents made the trip in the opposite direction, spreading out over the country. They had broad access to American technology and American industry. Evidently, someone important thought it was important enough to the war effort to allow that.

Air Force Major General Follette Bradley, who pioneered the Alsib Pipeline [the air route from Montana to Alaska to Siberia], would tell the New York Times:

Of my own personal knowledge I know that beginning early in 1942 Russian civilian and military agents were in our country in huge numbers. They were free to move about without restraint or check and, in order to visit our arsenals, depots, factories and proving grounds, they had only to make known their desires. Their authorized visits to military establishments numbered in the thousands. I also personally know that scores of Russians were permitted to enter American territory in 1942 without visa. I believe that over the war years this number was augmented at least by hundreds.

Rhodes, Richard. Dark Sun: The Making Of The Hydrogen Bomb (pp. 100-101). Simon & Schuster. Kindle Edition.

For the Manhattan project, the key spies were inside, with Klaus Fuchs being the most important. He was a talented physicist as well as a committed Communist from his teenage years, and he worked at the heart of two crucial efforts: the gaseous diffusion plant to separate fissionable U235 from U238 at Oak Ridge and the design of the explosive lenses that were the essential ingredient of the plutonium bomb.

The information gathered by the various spies was crucial to the Russian efforts, since the relative poverty and weakly developed technology in Russia made it impossible to carry out many of the experiments performed by the US, Britain, and Canada.

Rhodes has a lot of material on the spies, their psychology, and the tactics used to recruit them. Nearly all were motivated mainly by ideology. A common recruiting tactic used on the less committed was the appeal to a common enemy: Russia is our ally, we are just sharing information needed to confront the fascists. Israel has been known to use similar tactic on Americans.

Thursday, April 20, 2017

Finding ET

Actually, extra-solar planets, and just maybe, life out there. Chris Jones portrait of Sara Seager in the New York Times Magazine. A facinating human portrait of an astrophysicist bent on a cosmic quest.

Like many astrophysicists, Sara Seager sometimes has a problem with her perception of scale. Knowing that there are hundreds of billions of galaxies, and that each might contain hundreds of billions of stars, can make the lives of astrophysicists and even those closest to them seem insignificant. Their work can also, paradoxically, bolster their sense of themselves. Believing that you alone might answer the question “Are we alone?” requires considerable ego. Astrophysicists are forever toggling between feelings of bigness and smallness, of hubris and humility, depending on whether they’re looking out or within.

One perfect blue-sky fall day, Seager boarded a train in Concord, Mass., on her way to her office at M.I.T. and realized she didn’t have her phone. She couldn’t seem to decide whether this was or wasn’t a big deal. Not having her phone would make the day tricky in some ways, because her sons, 13-year-old Max and 11-year-old Alex, had a soccer game after school, and she would need to coordinate a ride to watch them. She also wanted to be able to find and sit with her best friend, Melissa, who sometimes takes the same train to work. “She’s my best friend, but I know she has other best friends,” Seager said, wanting to make the nature of their relationship clear. She is an admirer of clarity. She also likes absolutes, wide-open spaces and time to think, but not too much time to think. She took out her laptop to see if she could email Melissa. The train’s Wi-Fi was down. She would have to occupy herself on the commute alone.

Seager’s office is on the 17th floor of M.I.T.’s Green Building, the tallest building in Cambridge, its roof dotted with meteorological and radar equipment. She is a tenured professor of physics and of planetary science, certified a “genius” by the MacArthur Foundation in 2013. Her area of expertise is the relatively new field of exoplanets: planets that orbit stars other than our sun. More particular, she wants to find an Earthlike exoplanet — a rocky planet of reasonable mass that orbits its star within a temperate “Goldilocks zone” that is not too hot or too cold, which would allow water to remain liquid — and determine that there is life on it. That is as simple as her math gets.

Bits and Pieces

Among the many joys of Richard Rhodes Dark Sun are the biographical bits:

Once the magnitude of the disaster sank in, says Stalin biographer and General of the Soviet Army Dmitri Volkogonov, the dictator “simply lost control of himself and went into deep psychological shock.97 Between 28 and 30 June, according to eyewitnesses, Stalin was so depressed and shaken that he ceased to be a leader. On 29 June, as he was leaving the defense commissariat with Molotov, [Kliment] Voroshilov, [Andrei] Zhdanov and Beria, he burst out loudly, ‘Lenin left us a great inheritance and we, his heirs, have fucked it all up!’ ” Stalin retreated to his dacha at Kuntsevo; it took a visit from the Politburo, led by Molotov, to mobilize him. “We got to Stalin’s dacha,” Anastas Mikoyan recalled in his memoirs. “We found him in an armchair in the small dining room. He looked up and said, ‘What have you come for?’ He had the strangest look on his face.

Rhodes, Richard. Dark Sun: The Making Of The Hydrogen Bomb (pp. 42-43). Simon & Schuster. Kindle Edition.

Beria's repellent qualities apparently extended to having teenaged girls kidnapped off the streets to be raped in his office.

Wednesday, April 19, 2017

Venezuela on the Brink

Is Maduro finished? NICHOLAS CASEY and PATRICIA TORRES in today's NYT:

BOGOTÁ, Colombia — Protesters demanding elections and a return to democratic rule jammed the streets of Caracas and other Venezuelan cities on Wednesday. National Guard troops and government-aligned militias beat crowds back with tear gas, rubber bullets and other weapons, and at least two people were killed, according to human rights groups and local news reports.

President Nicolás Maduro defied international calls, including a plea from the American State Department, to allow peaceful assemblies and ordered his forces in

to the streets. Some demonstrators, wearing masks to protect themselves from tear gas, fought back with firebombs.


The One and Only Real Secret

I've started reading Dark Sun, Richard Rhodes' award winning history of the development of the fusion (H) bomb. (Hat Tip, Fernando). I've barely started, but I have to say that Rhodes is a compelling writer.

One thing that caught my eye was that key Russian scientists were aware of the possibility of a uranium bomb in 1939, and some were already advocating a strong program to try to build it. Two fundamental problems prevented it: the uncertainty as to whether a bomb would actually work, and the enormous expense required to find out. In the end it was decided that the necessary resources could be more usefully spent preparing for the coming war with Germany. The government did not trust the scientists enough to go for broke, and the scientists, with intimate knowledge of Stalin's terror, did not trust the government enough to go all out.

Rhodes sums it up:

Trust would not be a defining issue later, after the secret, the one and only secret—that the weapon worked—became known.

Rhodes, Richard. Dark Sun: The Making Of The Hydrogen Bomb (p. 42). Simon & Schuster. Kindle Edition.

Rise of the Cyborgs

Human's aren't quite surrendering to the robots yet. Maybe we will merge with them. Or just leave a few traces in their 'DNA' like the Neandertal did with us.

Kristen V. Brown, Gizmodo:

At Facebook’s annual developer conference, F8, on Wednesday, the group unveiled what may be Facebook’s most ambitious—and creepiest—proposal yet. Facebook wants to build its own “brain-to-computer interface” that would allow us to send thoughts straight to a computer.

What if you could type directly from your brain?” Regina Dugan, the head of the company’s secretive hardware R&D division, Building 8, asked from the stage. Dugan then proceeded to show a video demo of a woman typing eight words per minute directly from the stage. In a few years, she said, the team hopes to demonstrate a real-time silent speech system capable of delivering a hundred words per minute.

“That’s five times faster than you can type on your smartphone, and it’s straight from your brain,” she said. “Your brain activity contains more information than what a word sounds like and how it’s spelled; it also contains semantic information of what those words mean.”

I don't know, but I'm guessing they are reading sub vocalizations (or nerve impulses to your vocal apparatus) rather than the thoughts directly.

Bribery, American Style

Inaugural Fund Raising.

Tuesday, April 18, 2017


Ordered a book from Amazon, but I notice that it's being shipped via Royal Mail. I assume that means that it's coming from the UK (or maybe Canada or Australia - what do they call their post?).

Hope that it will be in a language I understand.

Book Review: Homo Evolutus

Juan Enriquez and Steve Gullans are venture capitalists and authors with an interest in life sciences. Gullans is a former professor at Harvard Medical school. Their book, or I should say micro-book, Homo Evolutus, seems to be based on a TED talk they gave. The subject is their thesis that the human race is about to "speciate," or give rise to a new species of Homo, thanks to the radical advances being made in biotechnology and genomics.

Roughly the first half of the book is devoted to background material on the evolutionary history of the various human species (19 so-far known, by their count) and their biological underpinnings. The rest is a quick catalog of some of the extraordinary goings on at the interface of biology and technology, many of which were unfamiliar to me. A couple of examples:

Not only did the two Chinese teams take mouse skin cells, and de-differentiate them back into pluripotent stem cells… They then took these stem cells and allowed them to re-grow, differentiate, and gave birth to live mice. Which then could reproduce normally.

Enriquez, Juan. Homo Evolutis (Kindle Single) (TED Books) (Kindle Locations 1372-1375). TED Books. Kindle Edition.

About a lab where synthetic organs are being grown using such tools as inkjet printers loaded with stem cells:

On a bench top, a freshly printed mouse heart beats away in a box. (Take that Edgar Allan Poe.)

Enriquez, Juan. Homo Evolutis (Kindle Single) (TED Books) (Kindle Locations 946-948). TED Books. Kindle Edition.

There is lots of similar stuff, including the cutsie asides, which I usually found slightly more amusing than annoying.

Homo Evolutus is (so-far) available only as a Kindle Single, and it's a very slender book indeed, only 58 pages, and that length is a great exaggeration due to it's idiosyncratically chatty format. It's more like a long magazine article. It's an hour or two of reading, and it's cheap, $2.99, Amazon only. I found it often interesting, and read about a number of things I had never heard of before. There are lots of endnotes and references for those who would like to check their work.