Why did I defend the geocentric model?

Diagram of Copernicus's answer to the geocentric system

In this eighth episode of the second season, I defend my defense of the Ptolemaic geocentric system of crystal spheres! I hadn’t even realized till I started recording that this is our 50th ever episode. I really should be so blown away that I’ve kept things going this long, but I’m not, somehow? Perhaps it’s just become a habit, and I stopped noticing milestones! But anyway, 50 episodes, I think that’s pretty amazing and I’m very proud to have made it this far. I’d like to thank every one of you for sticking with me for this long, and I’d also like to ask you to please let me know what you’d like me to do for the next fifty episodes!

Why I defended the Geocentric system

2:30

Today’s science explainy bit is not a question that anybody specifically sent to me. Rather, it’s something that people are generally quite curious to know: How am I, tireless crusader for the truth, able to justify my constant apparent defense for the old Ptolemaic system of a universe made from crystal spheres centered on the Earth? I think I make a pretty good argument, and you’ll find it in this episode.

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28:20

I didn’t want to stop this story with Copernicus because I think things get REALLY interesting when Galileo uses a telescope to properly disprove the geocentric model. He is a total heel about it, and the Church, desperately trying to protect itself from the reformation, sees Galileo as another troublemaker. As we all know, they tried hard to suppress him… it’s all just too fascinating, especially when you look more carefully and learn just how complicated Galileo’s relationship with the church and the elites really was! I don’t really have space to fit this in this season, unfortunately, but if enough of you mail me at podcast@urban-astronomer.com to ask for it, I’ll record it as a special bonus episode!

Last episode, I mentioned that we’re trying out a new community on the Flick app. It’s kind of like a social media network centered around podcasting. To me, it feels a lot like a classic web forum. To try it out, click the link at the bottom of the sidebar on urban-astronomer.com. Use the “urbanastronomer” join code. You’ll see existing conversations for each episode. There’s another one to introduce yourself, or you can start your own! It’s still early days, but the team behind Flick are working extra hard to build this thing, but even at this stage it feels like a great place for me to meet and chat with each one of you. It’s completely free, it is uncluttered with non-podcasty stuff, and I look forward to seeing you there!

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Comments

Why did I defend the geocentric model? — 2 Comments

Sean on 14 October, 2024 at 17:48 said:

I like thinking outside the box, and I think it is cool that you left this room for people to debate you, that being said, I can’t fathom (with all the info we have and info you can observe for yourself. Why would every planetary system we’ve found outside of our own geocentric system revolve around their star?

If you looked at a solar system outside of ours, with a good enough telescope, you would not see stars orbiting around a central planet, you only see stars orbiting around a more massive star (or Black Hole). If a geocentric model was the standard for planetary systems everywhere else. This is something you can actually see for yourself, if you’re observing the brightness of the star for a period of time. Periodic dimming of a star comes from planets transiting between us and their parent star. That’s one way to find planets. So if everything else is revolving around a parent star, why aren’t we? No other geocentric systems exist except for ours? It’s just crazy unlikely dude. I get thinking outside the box and that is what people really need to do when it comes to the cosmos, but you can’t keep holding onto a theory that’s been proved wrong so many times. It only makes sense if you stretched your imagination far outside what we have observed with more than just our eyes.

Reply ↓
- Allen Versfeld on 14 October, 2024 at 18:06 said:
  
  So I should probably make it more clear that I I don’t think the geocentric model is true. In in fact I would go so far as to say that it’s been impossible to believe in it ever since Galileo demonstrated exactly what you were talking about. His telescope was not powerful enough to show other planetary systems orbiting stars, but it was powerful enough to show the moons of Jupiter, and how they revolve around the planet. That alone was enough to prove that the Sun was not the center of all movement in the universe.
  
  So I’m not arguing that it’s true. Rather, I’m arguing that it was a reasonable belief in its time. Those complex models of planetary motion, with the epicycles, worked well and they produced quite accurate predictions of where the various lights in the sky were going to be at specific dates in the future. Of course they did – astronomers had had 1500 years to refine and tweak the geocentric model until it closely matched observed reality. In fact, they were quite a lot more accurate than Copernicus’s model (which made the mistake of assuming that all motion is circular). There would be no reason to abandon that model of the universe without Galileo’s observations.
  
  But then Galileo did make his observations. Evidence was produced that the theory was wrong, Kepler figured out the secret of elliptical orbits, and the rest is history!
  
  Reply ↓

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Why did I defend the geocentric model?

Why I defended the Geocentric system

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Why did I defend the geocentric model? — 2 Comments

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