A Bit More Detail

Assorted Personal Notations, Essays, and Other Jottings

Posts Tagged ‘comets

[BLOG] Some Monday links

  • Centauri Dreams reports on asteroid P/2016 G1, a world that, after splitting, is now showing signs of a cometary tail.
  • The Everyday Sociology Blog considers outrage as a sociological phenomenon. What, exactly, does it do? What does it change?
  • Joe. My. God. reports on a new push for same-sex marriage in Germany, coming from the SPD.
  • Lawyers, Guns and Money examines the Alabama government’s disinterest in commemorating the Selma march for freedom.
  • Marginal Revolution looks at Oxford University’s attempt to recruit white British male students.
  • At the NYRB Daily, Masha Gessen warns against falling too readily into the trap of identifying conspiracies in dealing with Trump.
  • pollotenchegg maps the distribution of Muslims in Crimea according to the 1897 Russian census.
  • Savage Minds takes a brief look at ayahuasca, a ritual beverage of Andean indigenous peoples, and looks at how its legality in the United States remains complicated.
  • Elf Sternberg considers the problems of straight men with sex, and argues they might be especially trapped by a culture that makes it difficult for straight men to consider sex as anything but a birthright and an obligation.
  • The Volokh Conspiracy considers how the complexities of eminent domain might complicate the US-Mexican border wall.
  • Window on Eurasia reports on protests in Russia and argues Belarus is on the verge of something.

[BLOG] Some Thursday links

  • blogTO notes that Uniqlo will be giving away free thermal clothing tomorrow.
  • James Bow shares his column about the importance of truth.
  • The Broadside Blog’s Caitlin Kelly shares with us her mid-winter walk.
  • Centauri Dreams reports about cometary water.
  • Dangerous Minds shares German cinema lobby cards from the 1960s.
  • Language Hat talks about dropping apostrophes.
  • Language Log reports about lexical searches on Google.
  • Lawyers, Guns and Money reports on the latest from Trump.
  • The NYRB Daily shares a review of an Iranian film on gender relations.
  • The Power and the Money’s Noel Maurer notes the ongoing gas price protests in Mexico.
  • Spacing links to some articles about affordable housing around the world.
  • The Volokh Conspiracy notes Germany’s abolition of a law forbidding insults to foreign heads of state.
  • Window on Eurasia suggests that stable Russian population figures cover up a wholesale collapse in the numbers of ethnic Russians, and looks at the shortages of skilled workers faced by defense industries.

[BLOG] Some Monday links

  • At Antipope, Charlie Stross imagines what might become possible with cheap heavy spacelift.
  • blogTO notes the vandalization of the iconic Toronto sign during Nuit Blanche.
  • The Dragon’s Gaze links to a paper considering the detectability of interstellar comets.
  • Language Log looks at Chinese language transcriptions for Obama, Hillary, and Trump.
  • Marginal Revolution looks at impending hard Brexit and notes how the economy of Thailand is dominated by Bangkok.
  • The NYRB Daily writes at length about its apparent discovery of the identity of Elena Ferrante.
  • Savage Minds shares a Bolivian perspective on Donald Trump.
  • Strange Maps shares a list of ten potential Jewish homelands outside of Palestine.
  • Window on Eurasia looks at quiet Chechen dissidence and warns about the consequences of Putin’s repressions.
  • Yorkshire Ranter Alex Harrowell worries about the people soon to be in charge of the United Kingdom’s Brexit negotiations.

[BLOG] Some Thursday links

  • Centauri Dreams looks at cometary breakups.
  • Dangerous Minds notes that a legal suit brought by a member of Kraftwerk has legalized sampling in Germany.
  • The Dragon’s Tales notes one group claiming that Planet Nine is a captured exoplanet.
  • Language Hat looks at a native speaker of Hindi who is learning Gaelic as an adult.
  • The Map Room Blog maps the decline of dialects in England.
  • Marginal Revolution notes an apparent collapse in Indian fertility.
  • Window on Eurasia notes Putin’s belief in the importance of spiritual bonds to hold Russia together.

[BLOG] Some Tuesday links

  • Bad Astronomy’s Phil Plait shares pictures of stellar shock waves.
  • Beyond the Beyond’s Bruce Sterling discovers he got the title of his blog from a Poul Anderson title.
  • blogTO reports on yesterday’s massive lineup for the Union-Pearson Express.
  • Centauri Dreams bids adieu to comet probe Philae.
  • Dangerous Minds shows us how the David Bowie instrumental “Crystal Japan” got used in a Japanese TV commercial for sake in 1980.
  • The Dragon’s Gaze shares the Kepler-454 system with its oddities.
  • Language Log talks about “Kongish”, a mixed Cantonese-English speech used for political protest in Hong Kong.</li"
  • The Map Room Blog notes misuses of maps.
  • At the NYR Daily, Charles Simic despairs after visiting New Hampshire.
  • Transit Toronto notes progress building infrastructure in Mississauga.
  • Window on Eurasia notes that Yandex News gets more sources from Facebook and Twitter than elsewhere.
  • Arnold Zwicky looks at the gay love songs of Eli Lieb.

[BLOG] Some Wednesday links

  • blogTO notes underground constructions, from subways to roads, which never took off.
  • Centauri Dreams suggests that an analysis of KIC 8462852 which claimed the star had dimmed sharply over the previous century is incorrect.
  • The Dragon’s Gaze looks at the greenhouse effect of water vapour in exoplanets and wonders if carbon monoxide detection precludes life.
  • Lawyers, Guns and Money notes the economic radicalism of early Marvel.
  • Marginal Revolution argues China’s financial system should remain disconnected from the wider world’s so as to avoid capital flight.
  • The Numerati reacts to the recent snowstorm.
  • Personal Reflections examines Australia Day.
  • The Planetary Society Blog depicts an astronomer tracking a comet.
  • The Russian Demographics Blog notes that Ukraine now hosts one million refugees.
  • Towleroad notes that gay refugees are now getting separate housing in Germany.
  • Window on Eurasia talks about the worrying popularity of Chechnya’s Kadyrov and suggests that when the money runs out Russia’s regions will go their separate ways.

[LINK] On how the Wow! signal of 1977 might be an artifact of cometary hydrogen

Gizmodo and Centauri Dreams each noted that the famous Wow! signal of 1977, one of the best candidates for an extraterrestrial signal, might be an artifact of comets. From Centauri Dreams:

We do know that the ‘Wow!’ signal’s intensity rose and fell over the same 72-second interval that the Big Ear itself could keep an object in its view — with a fixed field of view, the Earth’s rotation governed this. Hence Ehman could assume the signal had an origin in space, and Antonio Paris makes the same assumption. Scheduled to appear in the Journal of the Washington Academy of Sciences, the paper notes that the size of a comet’s hydrogen cloud is determined by the size of the comet, extending for as much as 100 million kilometers in width. The cloud increases significantly as the comet approaches the Sun. From the paper:

Since the rate of hydrogen production from the comet’s nucleus and coma has been calculated at 5 x 1029 atoms of hydrogen every second, the hydrogen cloud is the largest part of the comet. Moreover, due to two closely spaced energy levels in the ground state of the hydrogen atom, the neutral hydrogen cloud enveloping the comet will release photons and emit electromagnetic radiation at a frequency along the hydrogen line (1420.40575177 MHz).

Two comets are of interest. Looking back to 1977, Paris found that from July 27 to August 15, the Jupiter-family comets 266P/Christensen and P/2008 Y2 (Gibbs) were transiting near the Chi Sagittarii star group, placing them close to the source of the “Wow!” signal. [. . .]

If the cometary hypothesis is correct, this would explain why subsequent searches using the Very Large Array and the Ohio State University Radio Observatory between 1995 and 1999 found nothing, for neither comet would then have been near the right ascension and declination values of the original signal. Paris suggests that the period of 266P/Christensen (6.63 years) and P/2008 Y2 (Gibbs) (6.8 years) can explain why the signal was never again detected.

The idea that the Wow! signal was produced from clouds of neutral hydrogen emanating from the two comets seems quite a stretch, but usefully, Paris offers a way to falsify the hypothesis. We learn that comet 266P/Christensen will again pass through the neighborhood of the “Wow!” signal on January 25, 2017, while comet P/2008 Y2 (Gibbs) will be in the area on January 7 of 2018. So we will have the opportunity to test the notion and analyze the hydrogen spectra of the two comets. Shouldn’t the Big Ear have picked up the same cometary signature 24 hours later? We can’t be sure, but scanning the hydrogen signal from each comet sounds like a good idea.

Written by Randy McDonald

January 20, 2016 at 3:23 pm