Polygons (with line and point as guests)
Due to on observational evidence (no apparent motion of stars) ancient astronomers believed that the Earth was at the center of the solar system. The planets moved along concentric circles and everyone was happy. Some people noticed that the planets didn’t move in the sky as predicted by this model and epicycles were created to explain this. Planets move along the epicycle, and the epicycles move along a “deferent” circle.
I got accepted to present at my school’s student research competition! I’ll be giving a 10 minute talk about finding exoplanets. There will of course be Mathematica gifs. I’m excited.
Doppler shifting of a wobbling star.
In an Earlier Post I explained how stars hosting planets wobble due to mutual gravity. This wobbling can be observed by looking at the spectra of the star. Scientists don’t actually see the star wobbling, they see the frequencies shifting. By comparing the frequency shifts you can find the radial velocity of the star.