Tag Archives: astronomy

“Winter is Coming”

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Notes from A Song of Fire and Ice and SCIENCE: A panel on George R.R. Martin’s Game of Thrones series. Saturday, July 5, 2014, at Convergence 2014.

One of the distinctive features of this world is that the seasons last for multiple years, and the length of each season is unpredicable. How can this happen? Not by axial tilt, as on our Earth. Nicole Gugliucci said it could be achieved by planetary dynamics and referred us to “Winter is coming”. This paper (and I strongly recommend a look at the full paper as well as the abstract) suggests that the planet is orbiting a double star, in which case the orbit could be chaotic, leading to unpredictable seasons. Apparently (I have not finished reading the series) GRRM never explicity wrote that there was only one sun. In any case, one of the stars could be a roughly solar mass black hole, and hence invisible. Contrary to popular culture, black holes do not suck up everything around them. If you are in an orbit that stays well outside the event horizon you will never fall in. I asked about the long term stability of such a system. You want to be sure your planet stays in the “Goldilocks zone” — not too hot and not too cold. From “Winter is coming”:

To study the long-term stability of the CBP, we embarked on a long voyage of integration.
The orbit was stable after integrating for one million days. On Day 1,000,001 the Andals invaded. Funding cuts to all research projects promptly followed. We were unable to continue our work. Those of us who expressed strong opinions against the cuts were sent to the Wall.

You have to use days as your unit of time here because the years would vary in length. In winter they would be longer. I think these would also have to be sidereal days, certainly if both stars of the binary system are visible suns.

Avoiding “Sagan Syndrome.”

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Nathan Taylor, Why Astronomers and Journalists should pay heed to Biologists about ET.

Years ago I wrote something that mentioned similar issues: Extraterrestrial Intelligence: A skeptical view. This was long before the Kepler space probe. However, Taylor seems to be saying the fundamentals of the issue have not changed.

As Taylor points out, there is an ad hominem issue here. Frank Tipler, who was a forceful advocate of the no-ETs view in the early and mid 1980s, subsequently became a “crackpot” (Taylor’s word, but I agree completely). However, this does not invalidate Tipler’s earlier work.

Taylor also points out that for practical (creating life) purposes, the universe is still very young. Star formation will continue for a long time, a necessary condition for life. ETs may yet turn up, but you will need to be very patient.

Cool Discovery

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Another Incredibly Distant Member of the Solar System

Astronomers have announced the discovery of an amazing object in our solar system: 2012 VP113, an icy body with an orbit so big it never gets closer than 12 billion kilometers (7.4 billion miles) from the Sun! That’s 80 times the distance of the Earth from the Sun. No other solar system object known stays so far from the Sun. And at its most distant, it reaches an incredible 70 billion kilometers (44 billion miles) from the Sun—and it takes well over 4,000 years to circle the Sun once.

EDIT: See also A second Sedna! What does it mean?

Cosmos and Giordano Bruno

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I saw the first episode of the new Cosmos last week. The first and third parts were fine. The middle part, the cartoon about Giordano Bruno was the story I had heard long ago about how Bruno was a martyr for his scientific beliefs. This story is very widespread, and widely invoked by those who are hostile to religion. Back in 1971 I was in Turkey, on the walls of the formidable late medieval fortress of Rumeli Hisarı, when I saw a Soviet freighter passing through the Bosphorus named, in Cyrillic letters, Giordano Bruno.

Unfortunately, this was just cartoon history