Ptolemaic Planetary model

[woxingma8]

The reason an Earth centered model was accepted for so long was because there was no evidence (that could be measured with the tools of that era) that the Earth was moving.

[luismedina2008]

God Bless you.

[FriginHavoc]

@luismedina2008 this has nothing to do with any god.... This is philosophical science.

[abarrathemaster]

one of the main reasons that people didn't question the earth center mobdle is that Aristotle says say and in those days whatever aristotle says is true.

[Wittgensteinism]

Wow. Ptolemy really was a genius... he just so happened to be dead wrong

[josecitomadera]

I'd like to see a REAL model of this. Any suggestions?

[josecitomadera]

I think I've looked at this video 20 times already in a row. Dude, you've got a gift for production.

[TheToxicRadio]

i know it's incorrect but it would let you know where things would be in the night sky from an observable stand point on the earth and be correct.

[MrC0MPUT3R]

@TheToxicRadio You wouldn't be able to get anywhere in space though. :P

[TheToxicRadio]

@MrC0MPUT3R thats forsure.... you'll be like, ALRIGHT LETS GO TO- hey... somethings not here here :[

[TheTrebleGirl89]

The only thing that is incorrect in this model is that Ptolemy didn't place Earth as the center of the orbit. He had it stationary and opposite an Equant which is what the deferent of the epicycle was attached to. The velocity of the Planets movement on the epicycle was constant while the velocity of the center of the epicycle on the Deferent was not constant. Ptolemy added the (theta)e to the equation which was the angular velocity of the epicycle with respect to the Equant which was constant.

[MrKledzik]

The movement of the spheres is difficult to imagine, but this movie really helped me. The 3D version with red-blue glasses will be nice too. Excellent movie, music is nice too.

[mdanielsco]

Can someone explain in a little more detail what's going on? Here's what it looks like to me:

* The first 10 seconds are a time lapse movie of Saturn's path across the sky

* From 0:15 to 1:45 looks like Eudoxus' theory of homeocentric spheres. But his theory had four spheres per planet, and it looks like here there's three. And I'm not sure what the hard half egg-shell thing is near the end

* From1:50-2:40 is the Ptolemaic theory

* From 2:40-End is Copernicus.

Is there a better explanation?

[SounzNice]

Excellent illustration of retrograde of an "outer" planet - particularily after 1:40. Good video. Thanks.

[recoveringcultmember]

This is beautiful.

[puncheex]

From 0 to 0:28 you have what is observed from Earth about the motion of Saturn (and all the otherbodies, too, except the sun and the moon). They move, and then seem to stop, move backward (retrograde), and then go forward again. 0:28 to 1:50 shows some kind of "crystal spheres" solution; I don't know anyone who actually espoused it. 1:50 to 2:35 is Ptolomy's epicycle theory, and finally 2:35 to the end shows Copernicus' solution, the Earth becoming a planet along with the others.

[Jeorney]

No wonder they considered Saturn to be a rogue planet. That how the idea of satan arose. To borrow from Monty Python: "Saturn is not the messiah, it's a very naughty planet!"

[puncheex]

@Jeorney: Ah, but all the other planets, even Venus and Mercury do the same thing. Saturn is not unusual on that account.

[Jeorney]

@puncheex Venus has been associated with Lucifer, the morning & evening star - another rogue. What would Aphrodite would say :) Not sure of Mercury outside of greek/roman myth. Not that I believe all this stuff, but its interesting what the ancients made of it.

[puncheex]

@Jeorney: Then again, sometimes a cigar is just a cigar. All "planets" exhibit retrograde motion during some part of their/our planetary orbits, excepting only the sun and the moon, so it is not totally unusual, and it is not really apparent to anyone who doesn't closely watch them. It was known, but not thought to be indicative of some bellicose propensity, afaik.

[Magiman2011]

I have question cant find answer to

In this age of high tech i would have thought there would definitive proof but cant find any

Is there any absolute evidence /proof the earth goes round the sun and not the sun goes round the earth?

[olmecbones]

@Mgiman2011. Yes. The annual parallax of stars. But if you'd rather that the Universe be spun around you then you're certainly welcome to that relativistic observation because strickly speaking you would not be wrong. But I'd hate to have to figure out your Einsteinian tensor fields. ;-)

[puncheex]

@Magiman2011That question is answered by asking yourself what your reference is? If your reference is the the blue/red shifting of most stars, or measurements of the CMBR flux, then it becomes obvious that the Earth is mainloy (but not entirely) moving around the sun. In actuality, the both of them are moving around their common center of gravity.

[PawelKolasa]

COPERNICUS DOESN'T PROVIDE EVIDENCE THAT EARTH GOES AROUND SUN.

wake up!

It's not in his book. The whole theory is a sham

[Ennio444]

Aristarchus of Samos (IIIrd Century BC) did theorize about that. And from Roman times on, the theory was known, although the Church rejected it, as rejected the round earth officially (although many clerics did believe that the Earth was round, as many people did since Ancient Greek times). Many people, scientifics, sages and philosophers, believed in heliocentrism before Copernicus, even though the Church rejected it, just as they didn't believe in God's power to strike them down with a plague.

[malonekk]

This is lovely . . . what is that piece of music?

[puncheex]

@malonekk: Mendelssohn's violin concerto.

[tzone92]

Explanation: As the Earth moves around the sun, and passes by other plants moving around the sun, but slower because they are farther away, the planets appear to move backward and then forwards again, because the Earth is moving faster than them. To explain this while preserving the Earth-centric solar system, the Greeks showed that this "apparent retrograde motion" could be explained if planets did not orbit in one circle around the Earth, but around a circle that orbited another circle, etc.

[go123453]

I couldnt have put it better myself

[LiquidSmooth]

hmm, i wonder what the Mayans believed and a few other ancient astronomers, cause htey seemed to be more advanced than us in many ways.

[puncheex]

@LiquidSmooth: In some ways, perhaps, but there is no evidence that they had the precision instruments that the Europeans had, even before telescopes. Without them this kind of precision is unattainable.

[ChemicalROSElie]

I liked a lot, a work well done, simulations estraordinarias. It was me very useful. . . and the sound trail, an espataculo to the part! congratulations! ! ! !

[jasonguyperson]

inaccurate* (this is a correction to my previous comment)

[joshuaslong]

Thank God for Occam's Razor

[jasonguyperson]

and Galileo

[soulofjimi]

can somebody please tell me what I just watched? Very interesting, but I do not get it.. Ptolemaic

[jasonguyperson]

It was an early mathematical model to explain the mysterious motion of the planets - back when our ancestors thought the earth was the center of everything. It is quite clever, but ultimately inacurate.

[soulofjimi]

oh, yea dude music was cool.. Yea that seems logical.. Do you ever still wonder about Steady State Theory compared to the big bang, especially if you take string theory and quantum entanglement into account?

[psychosavant]

Look up Ptolemy. He was an ancient philosopher. Arguably the first to publicly question the idea of just accepting without looking for evidence and for that is a very celebrated philosopher. Even though his idea about a geocentric solar system was incorrect, Ptolemy did provide a suprising solid mathematical explanation for the pattern exhibited by planets that moved throughout the night sky. Later, other philosophers would show the sun, not the earth, was the centar of the solar system.

[soulofjimi]

yea, well what about Steady State Theory compared to the big bang, especially if you take string theory and quantum entanglement into account?????

[psychosavant]

You were asking what you were looking at. I was telling you it was the Ptolemaic model (that is the model of the universe as thought of by Ptolemy). This has nothing to do with the Steady State Theory, the big bang, string theory, or quantum entanglement. There is no quantum physics or question of the origin in the universe involved in the Ptolemaic model. It a question of the structure of the solar system as the planets position relative to the sun.

[puncheex]

@soulofjimi: What about it? The Big Bang explains the Cosmic Microwave Background Radiation, Steady State doesn't. Pretty much end of the story. No need to bring in strings, or Quantum entanglements or anything else.

[recoveringcultmember]

@psychosavant Why was it incorrect?

[puncheex]

@soulofjimi: The basic problem is, why do the planets move as they do as observed from Earth? Ptolomy, using the axiom of movement in circles, had to add circles within circles to (and later, even more of them) to make the measurements come out right. Copernicus solved a lot of problems by making the Earth one of the planets, all going around the sun; Galileo proved that by observing phases and the example of Jupiter. Kepler finished by abandoning circles for ellipses. Newton explained why.

[thanhsonluong]

Ptolemy (aka claudius ptolemy) was a Roman citizen of Greek descent who lived in Egypt ;)

[monsieurhassan]

What kinda motion is that towards the end, beginning at around 1:50 . .. when there's a planet and another small thing moving with it . .. is it a moon?

[heliocentricist]

Ah, i remember the epicycles. they used to make me chuckle! :D

[nixter888]

Do you think i don't know that!!!!He was an other GREAT GREEK IN A GREEK CITY!!![ALEXANDRIA],or you forgot that!!!

[nixter888]

Do you think i don't know that!!!!He was an other GREAT GREEK IN A GREEK CITY!!![ALEXANDRIA],or you forgot that!!!

[nixter888]

Alexandria was founded by Alexander the Great in 332 BC as Ἀλεξάνδρεια (Alexándreia). Alexander's chief architect for the project was Dinocrates. Alexandria was intended to supersede Naucratis as a Hellenistic center in Egypt, and to be the link between Greece and the rich Nile Valley.

[nixter888]

Alexandria was a center of Hellenism. The early Ptolemies kept it in order and fostered the development of its museum into the leading Hellenistic center of learning (Library of Alexandria)!ALL GREEK!

[AdventuresWorld]

Please, can you explain me something about it??

[princefy]

the last system is the solar system we talk about nowadays--the old system was the first--please study einsteins theories-remember theories are still theories--the new system has not yet been proved beyond a reasonable doubt

[crazy650c]

Why is the system shown sun-centered at the end?

[puncheex]

@crazy650c: That's Copernicus' solution - make the Earth a planet like the rest, and the retrograde motion becomes apparent. For a while after Copernicus published (after he died), Ptolemy hung on because his three-layered epicycles were actually more accurate than Copernicus. When Kepler finally make the circles ellipses, the system became hugely more accurate.

[crazy650c]

@puncheex Thanks. Of course you know that the earth does not move. It is the center of the universe. All the universe spins around the earth in an helical pattern northward and then southward, in repeating cycles. How in the world fools think the atmosphere remains stationary with respect to the earth while the earth supposedly spins at thousands of mph - which violates the laws of physics is just amazing to me.

[puncheex]

@crazy650c: Of course I don't know any such thing. There is no "center of the universe". The atmosphere remains on the Earth because gravity keeps it there. According to you Venus, Jupiter and Saturn don't have our excuse for the atmosphere remaining where it is, and yet on each of them it does (also for Uranus, Neptune, Mars and Titan, come to think on it). Your concept of physics is much too small and self-fulfilling.

[NeoEllis]

Excellently done, that was really something.

[propdude1]

Great video. Helped me with my History of Science and Technology exam. Too bad Ptolemy's not in pop culture or because then your video would get far more views that it deserves.

[emjaymoggs]

if only

[racheldizon]

cool video. thanks!!

[nixter888]

An other Greek INVENTION,an GREEK wonder!

[planetics]

!!!

excellent video !!!

!!!