Wednesday, January 4, 2012
St. Anthony's Greek Orthodox Monastery
The Earth's Orbit
We are at a point in the earth's orbit that is closest to the sun.
The autumn and spring equinoxes are separated by approximately 1/2 year. In fact, there are three more days in the period from the spring equinox, about March 20,21, to the fall equinox, about September 20,21, than there are in the September to March time. This discrepancy was probably known to the ancients, as all calendars marked these times as important for migrations, agriculture and other cultural needs. The actual explanation for the differing day count came from Johannes Kepler, 1571-1630. Kepler realized that the orbit of the earth was not a perfect circle but an ellipse with the sun at one focal point. This meant that we were closer to the sun at certain times of the year and orbiting faster during those periods. He did not fully realize that gravity was the cause of our orbital motion so only could hypothesize rules based on observations that would describe the orbital motions of the planets. The physics community would have to wait for Isaac Newton, 1642-1727, for the idea of "action at a distance" and a quantifying rule for gravity.
In a modern introductory Celestial Mechanics course, Kepler's three laws form the basis for that course. The laws are:
- The orbits of the planets are ellipses with the sun at one focus.
- The equal area rule which states that if you connect a line from a planet to the sun, that line will sweep out a certain unit of area for a given time at any point in the orbit.
- The Harmonic Law, K = R cubed/T squared. Please excuse the non-mathematical notation, I'll get the format figured out eventually. This law states that for any object orbiting another object, the ratio of the radius of the orbit cubed to the period of the orbit squared is a constant value. To calculate the value of K for the sun we can use the earth's orbital parameters. Therefore K for the sun = 1 astronomical unit cubed/year squared. Mars is about 1.5 times further from the sun and takes 687 earth days to complete an orbit. The K value calculated from this data is 0.97 au cubed/ yr squared. The other planets return values very close to these numbers. Kepler did not know about Neptune, Uranus and Pluto, but we can calculate their K values and we find that they are also very close to 1.
There we are. We orbit the sun in an elliptical path and we happen to be nearest the sun on about 4 January each year. Our ellipse is very nearly a circle so we stay at nearly the same distance from the sun all year.
The Kepler Museum in Regensburg, Germany has a very informative and interesting display regarding Kepler's life and work.
This is not an official federal paid holiday, but I hope that you will celebrate anyway.
Tuesday, January 3, 2012
The GlassStacker in a babushka
Tuesday, December 20, 2011
Our Big Healey, 1957 100-6
http://www.mnhealey.com/mnhealey/newsletter/2009/Mar%202009%20enthusiast.pdf
Thursday, December 15, 2011
The Cuban Cigar
The GlassStacker and I were in Cabo San Lucas last week and I thought it would be fun to smoke a Cuban cigar. Finding a place to buy the cigar was easy, apparently a good fraction of the gringo tourists want this experience so the cigars are very readily available, for a price. So I bought the stogie, not a small or large cigar, just a medium, very mild, smoke. The store clerk said it would take about a half hour or so to smoke.
Toward the end of our stay I realized that I might not be able to import this purchase into the US of A. This necessitated my smoking the cigar in Cabo San Lucas. Our week was nearly gone so the deed had to be done now.
On Thursday afternoon, I took a regular pair of scissors and just cut the end off the cigar. That done I hunted around for a book of matches, not easy to find in a non-smokers domain. I eventually found a book in the bathroom supplies. Now I had my stuff together.
Where to have this illicit pleasure. The Boss was adamant about one thing and suggestive about another. She was not going to have this event polluting her airspace. That seemed non-negotiable to me, so I planned around her airspace by going out on the beach to a location not too close to anybody. I had my own airspace. The other item that concerned her was that I might be sick. I had not even considered that possibility. How could that happen? Now I had to be isolated in case the unthinkable did happen. The beach was a good choice.
The beach was a good choice until I tried to light the cigar. A fresh breeze made that tough. Never mind that I am a reformed smoker who knows how to light a smoke in the wind. It took several tries, many tries, to get it going. On about the middle try, I burned my thumb! Rats. But joy, eventually I got it lit.
Joy is a fleeting thing, as only about five minutes elapsed before I decided to put the cigar out. I'd had enough. I will rationalize and say that I had all that I needed. Just that initial taste... Now that I was done, I couldn't leave a hot ember in the sand, somebody would step on it, so I had to get it all out and take the stub to a trash can. I enhanced my experience by burning my index finger putting the cigar out.
I didn't get sick, my thumb and finger are nearly healed, my moustache and beard only smelled of tobacco for a couple hours and I have enough money to pay my Visa bill when it comes next week. It was all worth it.
Tuesday, October 12, 2010
Knees for the Future
The weather has been most agreeable and I have been able to walk the neighborhood. I am already going farther afield than I could before the surgery. I truly appreciate this.
That is all for now. Eat, sleep, read, exercise and keep 'em running.