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Tag Archives: astronomy
Happy Lady Ada Day!
In accordance with the Pledge, I would like to recognize the work of Vera Rubin. She discovered most of the matter in the universe, an accomplishment that really should be better known.
Via Make.
Home State Stupidity
Illinois plutocrats are frakkin’ goofy
The government of Illinois, an an obvious attempt to distract America from Blagojevich’s hair, has declared that Pluto is a planet.
[snip]
That’s OK though, Illinois congresscritters. I’m sure there’s nothing else for you to do with all your spare time. But y’know, I hear those pesky Hoosiers next door want to make π equal to 3! Hurry! You can still beat them to it!
Mercury in free fall
I am not referring to the planet, although that is also (and always) true.
I posted before about the temperatures on December 15 and this past Tuesday.
This morning I saw a thermometer reading -22oF/-30oC.
However my car, a ’95 Ford Escort, was still able to start. There was a bus waiting at the Park-and-ride, and it stopped downtown across the street from a Skyway entrance. So my total exposure to the weather was probably under 5 minutes.
I just checked the forecast. It may be a full 17oF/9oC warmer when I go home!
Windycon
mia_mcdavid and I are at Windycon. We attended this convention for 20 years when we lived in Chicagoland and it, with some help from Capricon, defined our sense of what a science fiction convention should be. We are having a great time. Continue reading
Seeing is believing
I was particularly struck by: “Then they discovered an old observation from 2004, which also showed the planets and how far they had moved around the star in three years.” Similar discoveries of old observations occurred after Neptune and Pluto were found in our own solar system.
Living History
From Bad Astronomy:
….there’s something cool about old’ [tele]scopes. It’s hard to imagine any other scientific instrument in any other field that can still produce good quality data after more than 100 years.
The universe is a dangerous place
Tunguska centennial
Celestial Mechanics
Alessandra Celletti and Ettore Perozzi, Celestial Mechanics: The Waltz of the Planets. This is a semi-popular look at one of my old and persistent interests. Very little math, but a lot of graphs and terminology. It includes the traditional subjects, e.g. tidal forces, the discovery of Neptune, Delaunay’s lunar theory, and the stability of the solar system. but the emphasis is on modern developments, e.g.
- Modern dynamical systems theory and chaotic motion.
- Trojan satellites and Lagrange Points–L1 can actually be useful, even though it is unstable.
- Artificial satellites and space travel, including Hohmann transfer orbits.
- Planetary ring systems.
- The Kuiper belt, the outer solar system, and the demotion of Pluto from planetary status (correct, IMHO).
- Planets around other stars.
A unifying theme is the importance of resonant orbits. For example, Neptune makes three orbits around the Sun in about the same number of years as Pluto makes two. This is not a coincidence.
Recommended for those with some general knowledge of astronomy.
From Hilbert Space to Dilbert Space, and beyond 