Saturday, March 10, 2018

My head hurts, or I dare you to read the link in this post all the way through, or a little light reading as the equinox approaches

Did you ever wonder how Kepler differed from Copernicus?

Me neither.

Nicolaus Copernicus (1473-1543) had a certain view of things having to do with the sun, the moon, the earth, and the planets. Then along came Johannes Keppler (1571-1630) with a slightly different view of things. It's all made clear (or not) in the following article from Wikipedia:

Kepler's laws of planetary motion

Basically, Kepler's three laws are:

1. The orbit of every planet is an ellipse with the Sun at one of the two foci.
2. A line joining a planet and the Sun sweeps out equal areas during equal intervals of time.
3. The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.

So, basically, it's as simple as 1, 2, 3.

Yeah, right.

Here is an illustration that makes things ever so much clearer:

As I was saying, yeah, right.

But perhaps the most disturbing statement in that article is this:

the semi-latus rectum p is the harmonic mean between rmin and rmax

I fervently hope someone invented a laxative for that.

To me, the most interesting thing I learned from reading the article is that the eccentricity of the orbit of the Earth [that is, it is elliptical, not circular as Copernicus had thought] makes the time from the March equinox to the September equinox, around 186 days, unequal to the time from the September equinox to the March equinox, around 179 days.

If you read the entire article and your head has stopped spinning, now that you have had your horizons expanded (as it were), please join me in singing Here We Go Round the Mulberry Bush (4:44), not once, but twice, complete with instructions on personal hygiene and planning your day.

Finally, which came first, the chicken or the egg?




  1. It is too early in my day for my brain to hurt this much.

  2. I would give you some sort of coherent statement but my eyes are still rolling around in their sockets. I wonder if the rolling motion is circular or elliptical.

  3. You wrote this (and read the original) in preference to pulling your hair out with tweezers?

  4. Attention two Australians and a Nebraskan: See my comment on the previous post (March 8th)....

  5. I've now finished my lunch. I shall avoid giving myself indigestion.

  6. Thanks for this. Can we have some Quantum Physics for dessert please?