[PHOTO] Wind chimes from below

The wind chimes that sound outside my door look distinctly geometrical from below.

[BLOG] Some Friday links

• 80 Beats links to a profile of Taiwanese computer programmer Kevin Wang, the man whose humourous animations of news events have created for him a worldwide fandom.


• At Centauri Dreams, Paul Gilster discusses the implications of theories of planetary formation suggesting that the number of free-floating planets far exceeds the number of star-orbiting planets (or stars, even) for interstellar migration: island-hopping in the Oort to the next star over?


• Crooked Timber's Rich Yeselton discusses Mitt Romney's alternating use of "Democratic" and the insulting diminuitive "Democrat" on the campaign trail. At the very least, Romney may not be a man without qualities, but those qualities are invisible.


• Eastern Approaches links to two blog posts on ethnic tensions with international implications in the Baltic States, one on a polarizing referendum in Latvia on granting the Russian language official status, the other on a Polish-Lithuanian dispute over the Lithuanization of Polish names.


• Geocurrents has a post outlining the long history of Russian/Russophone immigration to the San Francisco Bay area.


• At Registan, Wendell Schwab discusses the patronage in Kazakhstan of religious art and places of worship by politicians, apparently a controversial bypassing of the state.


• Slap Upside the Head is rightly unimpressed with the Ontario public Roman Catholic school system's substitute for gay-straight alliances in its schools.


• At Spacing Toronto, Noah van der Laan discusses the world's largest streetcar network in Australia's second city of Melbourne. Lessons there!.


• Finally, in the aftermath of Whitney Houston's death Torontoist gathered and shared vintage news articles about Houston's presence in Toronto. The reviews were very good, although one reviewer's excitement at imagining what her voice would be like in two decades (after her mid-1980s appearance) is inevitably sad.

[LINK] "Alpha Centauri B: A Close Look at the Habitable Zone"

Paul Gilster's space-centered blog Centauri Dreams takes its name from Alpha Centauri, the nearest star to Earth. To the naked eye a single star visible only on Earth from the Southern Hemisphere, through the telescope it turns out that Alpha Centauri includes three stars, with two of these stars being pretty Sun-like stars in a stable orbit that could support planets with Earth-like environments. Gilster's most recent post examines the prospects for an Earth-like planet orbiting Alpha Centauri B, the dimmer and oranger of Alpha Centauri's two Sun-like stars. B has become a major target of astronomers since it's the less massive of the two Sun-like stars, and it would be easier to find an Earth-mass planet around B than around A.

What's the story? First, the background.

Centauri A and B, being high metallicity stars, are presumably prime candidates for circumstellar disks with a high solid material component, making the building blocks of planets readily available, and deepening the spectral lines for improved precision in radial velocity studies. Another useful factor for observations is that the binary is inclined by only 11 degrees with respect to our line of sight, an important fact because it means that any planets we discover through RV methods will yield a mass that is fairly accurate, assuming that the planets around these stars have formed in the same orbital plane. Without such knowledge, the mass figures from RV studies vary widely depending on assumptions about the target system’s inclination.

Studies on planet formation have shown that both Centauri A and B should be capable of forming terrestrial planets even when the perturbations caused by the binary companion are taken into account. Early studies on this question have found that the planetesimal disks seem to be stable out to about 3 AU of the parent stars, assuming a reasonable inclination of the disk relative to the binary plane, meaning something less than 60 degrees. More recent work by Thébault and colleagues has shown that the later stages of accretion may not be efficient because the binary companion can inhibit the growth of larger objects outside 0.75 AU (Cen A) and 0.5 AU (Cen B).

What does this mean? Most likely that the formation of gas giants is unlikely here (a finding that squares with previous radial velocity surveys), while if we can get past the problem of forming larger planetesimals referred to above, Earth-mass planets should be able to form in the habitable zone of Centauri B, assuming an eccentricity of no more than 0.3. A 2009 study I’m not familiar with by Michtchenko & Porto de Mello makes the case that any terrestrial planets that do form in Centauri B’s habitable zone should be dynamically stable despite perturbations from Centauri A under certain conditions of eccentricity and orbital inclination, but planets with inclinations to the orbital plane larger than about 35 percent should experience strong instability.

Next, comes the question of where B's habitable zone--the area of space where a world could conceivably support a moderate Earth-style climate, not too hot like Venus' nor too cold like Mars', orbiting around its sun.

Kasting and team used a model that assumed Earth-mass planets with similar atmospheric composition and found a habitable zone ranging from 0.5 to 0.9 AU, although this 1993 study did not include the perturbing influence of Centauri A. But [in a new paper astronomer Duncan] Forgan notes this with regard to the light reaching Centauri B planets:

If main sequence relations for the luminosity of each object are assumed, the insolation experienced by planets in the habitable zone of α Cen B due to α Cen A would be no more than a few percent of the total insolation of the α Cen AB system at the binary’s periastron, and around one tenth of a percent at apastron. This insolation can be diminished further by eclipses of α Cen A by α Cen B, the duration of which is estimated to be of order a few Earth days.

[. . .]

So what does Forgan find? It turns out that calculating the habitable zone of Centauri B’s inner and outer boundaries can be roughly correct if we leave Centauri A out of the picture — the dimensions of the habitable zone remain more or less the same. But adding Centauri A does create oscillations in the planet’s climate that happen when Centauri A is at its closest to Centauri B. The temperature variations caused by Centauri A are no more than several K, and could alter the fraction of habitable surface on planets at the habitable zone boundaries by about 3 percent, a figure made flexible depending on the size of oceans or planetary obliquity.

The paper goes on to note the possible effect on life (science fiction writers take note):

It is reasonable to speculate that if life were to exist on planets around α Cen B, that they may develop two circadian rhythms (cf Breus et al. 1995) corresponding to both the length of day around the primary, and the period of the secondary’s orbit (approx 70 years). Altering the available habitat by a few percent may also influence migration patterns and population evolution.

The impact of B on a planet orbiting A would be lesser, I'd think, since B is the dimmer star and would have proportionally less effect.

[BRIEF NOTE] On changing attitudes to homosexuality in China

Joe. My. God linked to an eyecatching Xinhua article on support for GLBT rights.

More than 80 percent of Chinese people born after the 1980s hold no discriminatory beliefs regarding homosexuality, according to a survey on marriage perspectives conducted by jiayuan.com, a major Chinese dating website.

The survey results, which were published in the Monday edition of the Beijing News, indicate that 83 percent of respondents born between 1980 and 1989, as well as 82 percent of those born after 1990, do not disapprove of homosexuality.

This survey has to be taken with a non-trivial amount of skepticism. Is jiayuan.com's surveyed population representative of the Chinese population at large, for instance? What exactly does "no discriminatory beliefs regarding homosexuality" mean? Still, compared to the United States where as recent as 2008 a Gallup poll on the subject revealed a roughly even split over the moral status of homosexuality and even adjusting for the well-known phenomenon of younger demographers being more pro-gay than older, figures in excess of 80% are noteworthy.

What's up? Commenters at Joe. My. God. highlighted the contributions of gay-positive sexologist Li Yinhe for this rather high figure, along with more broadly a lack of the religious opposition to homosexuality found in the West in indigenous Chinese traditions. Presumably without deep-seated objections to homosexuality as a moral issue, rapid shifts in public opinion would be considerably easier than in the West.

Homosexuality as a moral issue, however, is one thing. Homosexuality as a lived experience compatible with expected behaviour, however, is another. This China Daily report on gay life in China on Valentine's Daily makes the point that whatever changes have occurred on homosexuality as a moral issue, as a practical issue homosexuality is incompatible with familial expectations.

"Love can exist between a boy and a girl, and so it does between a man and a man, and a woman and a woman, doesn't it?" said Li Yinhe, a renowned female sexologist with the Chinese Academy of Social Sciences.

She said that on this day of love, the gay community also wants to, and should, express love for their partners.

"It's good to see that Chinese gays are more active nowadays. Society has been more and more inclusive, and they have begun to step into the sunshine from the dark," Li said.

Li's comment reflects a recent survey on marriage perspectives conducted by jiayuan.com, a major Chinese dating website, which found that over 80 percent of respondents born after the 1980s bear no discriminatory beliefs regarding homosexuality.

However, most gay lovers prefer to get into the Valentine's spirit in a low-key manner.

A gift may not be necessary, and gay couples often opt to go to a gay bar or a less public place where their intimacy won't make them too "noticeable."

"After all, we are different. If we walk hand-in-hand or kiss in the street, people will see it as abnormal, some may stare at or even laugh at us," said a gay man surnamed Xie, who celebrated Valentine's Day by having a simple dinner at a local restaurant with his boyfriend.

Meanwhile, the holiday is more bitter than sweet for those gay men who have married women.

Mu Sen, a fashion stylist living in Hangzhou, the capital city of Zhejiang Province, had a tiring day commuting from his "underground" boyfriend's house and his home.

He skipped work and drove a long way to his boyfriend's house to give him a gift and have lunch with him during the day. But, in the evening, he will make dinner to please his wife on this special day.

"My boyfriend wants me to stay with him the whole day as he values this festival a lot," he said, "but, you know, I am a husband and will soon be a father to my second child."

Li, who has been fighting for the recognition of homosexual marriages in China, called on gay men to avoid marrying women.

Li said that the situation for gays in China has indeed become much better, but pressures remain. These pressures can compel a gay man to choose to marry woman -- a so-called "normal marriage" -- but sometimes become a source of tragedy for the gay men and their wives.

This is not so different from the situation in the West at all.