I had a long discussion the other day with my sister during which I told her how one-fifth of North-American believe that the the Sun is orbiting the Earth. I kept thinking about this after the end of the discussion, and I was wondering if there was a way to demonstrate to people, by a sort of experience that everybody can do on their home, that it is in fact the Earth that is moving around the Sun. I was thinking of something like the experience were you put a non-moving stick of butter in a microwave oven, measure the distance between the melting point and by multiplying by the frequency of the microwave, demonstrate the speed of light. Obviously if it took until two hundred years ago to find this proof, that was probably more complex that I expected. But perhaps that, like the measurement of the speed of light that everybody can do at home thanks to the availability of stuff that scientists did not had access to in the past, there was a way to also reduce the complexity to a combination of available equipment (I am an incorrigible optimist who believe that any problem can be solved by time and a better education).
Certainly the most understandable proof that we have today is that we are capable to send missions to Mars and that this would be impossible if our knowledge of how the solar system works was wrong. But that would be forgetting that most people who believe that the Sun is orbiting the Earth probably also believe that the travels to the Moon were an hoax, so we are back to the same problem: Until people can do the experience themselves, there is no way they will believe it. This is the reason why those people say that evolution is just a theory when they have no problem with the gravitation theory.
So I started to search what was the proof that the Earth is orbiting the Sun (I had no idea myself what was this proof, even if I do not remember ever having any doubt about this). The most fascinating one was called the aberration of light and was soon searching what kind of hardware James Bradley used to make this discovery. I knew it was some sort of meridian telescope and I was thinking that hooking up a Celestron telescope with a webcam connected on the Internet would permit to show to everybody the movement of the star that indicates that the Earth is moving on an ellipse – hoping that the progress in optics and computer would permit to replicate the experience. This is how I went to read on Google one or two pages of “Parallax: The Race to Measure the Cosmos”, immediately order it on Amazon, and read it back to back on two evenings. The book is a fascinating reading and I strongly recommend but it was a disappointment to discover that the kind telescope used by Bradley was still out of reach for an amateur (Here’s a picture that shows exactly what I mean).
I have some ideas on how to perhaps solve these problems but by lack of available time this project will unfortunately have to go on the “things to do when I am retired” folder. But that was a great book to read.