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Thanks for posting. Great article. A word of caution about Kepler's discovery of elliptical orbits. We usually encounter this topic in physics textbooks who ill
by nyc111 8y ago
Thanks for posting. Great article. A word of caution about Kepler's discovery of elliptical orbits. We usually encounter this topic in physics textbooks who illustrate the ellipticity of planetary orbits with highly eccentric ellipses of probably 0.7 or more ecentricity. But, as an example, the eccentricity of Venus' orbit is 0.0068! So if you draw such an ellipse on letter size (or A4) paper you cannot tell it apart from a circle.
- dustfinger 8y agoThanks! I am glad that folks here found it engaging :-). Plus, I have learned a lot reading the comments. Thank you all for your contributions.
- acqq 8y agoThat the modern illustrations are wrong doesn't diminish what Brache correctly measured and Kepler carefully figured out by his calculations.
- nyc111 8y agoI agree. It's not their fault. What interests me is this: If the eccentricity of planetary orbits is so small, I wonder if we can still uphold the circularity of orbits, but place the sun slightly off center? Will this geometry save the observations?