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Archive for November, 2015

Your Turn, Round 2-6: How to Escape From a Gas Giant

Between 2 and 3 years ago, I did a series of posts describing a sciencefiction setting of my own invention.  I was exploring different ways one might resolve the Fermi Paradox.  For those unaware, the Fermi Paradox goes like this: We observe many places in the universe where technological life could appear and persist; but we have no evidence of alien visitors to Earth.  Where is everybody?

The default solution to this paradox is to have technological life be rare in the universe.  Other possible solutions include civilizations encountering various problems; barriers that prevent them from traveling or sending robotic emissaries across interstellar distances.  So I call the setting “Fermi Problems” (geeky reference is geeky).

One situation I considered was life on a gas giant; specifically a hypothetical superjovian planet around HIP 66461, a G-type star 150 parsecs from the Sun.  Since HIP 66461 is in the section of sky allocated to the constellation Ursa Major, I called these hypothetical aliens the ursians and the planet Ursa.  I had thought that Ursa was a deep enough gravitational well that the ursians could never escape without outside intervention.  I may have been wrong.

So, How Do You Escape From A Gas Giant?

To go into orbit around a gas giant with 2.8 times the mass of Jupiter, you have to acquire a speed of at least 50 km/s.  Escape velocity requires twice the energy of the minimum orbital speed – i.e. 70 km/s in velocity, plus a bit more to account for the remaining gas drag.  That is very fast.

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Fantasy Round 42: The Aeronaut’s Windlass

2015/11/15 Leave a comment

The Aeronaut’s Windlass is a new book from Jim Butcher (the author behind The Dresden Files) and it is nifty.

It’s also the first book in a planned nine-book series (called The Cinder Spires).  My plan is to buckle in for a wild ride.

Also: not too many spoilers here, so go right on ahead.

Not shown in this picture are the lines and buckles that any sensible airship captain and crewmember uses to avoid falling overboaord or getting concussions when exciting things happen. (Also, exciting things happen.)

Not shown in this picture are the lines and buckles that any sensible airship captain and crewmember uses to avoid falling overboaord or getting concussions when exciting things happen.
(Also, exciting things happen.)

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