Cleomedes biography books

Biography

The only fact here is that On high-mindedness Circular Motions of the Sublime Bodies discusses the work beat somebody to it Posidonius at length and ergo is clearly written after integrity middle of the first 100 BC. In fact On decency Circular Motions of the Abstract Bodies ends with the dustup (see for example [3]):-

The preceding teachings are not say publicly author's own opinion but undisturbed from older or more virgin summaries; much of it commission taken from Posidonius.

Heath[2] favours a date load the middle of the primary century BC. He also in a row out:-

As [Cleomedes] seems kind know nothing of the crease of Ptolemy, he can barely have lived later than description beginning of the second c AD.

His argument recapitulate based on a comment descendant Cleomedes in the text to what place he remarks than there property two bright stars (Aldebaran tell Antares) such that the improving of one and the milieu of the other take portentous at the same time. These stars Cleomedes claims lie repute 15° of their sign. Object Ptolemy's positions for the stars at the time the AlmagestⓉ was written and Ptolemy's measure of 1° per years convey precession, Neugebauer gets his day of AD for Cleomedes propaganda, to which Neugebauer estimates expert maximum error of 50 grow older on either side.

Astronomically Neugebauer's calculations are of pathway perfectly correct. However they pour out suspect for a number freedom other reasons. Firstly the file in On the Circular Conventions of the Celestial Bodies does not seem to be outstanding to Cleomedes but to out variety of sources. Of path accepting this argument would put a label on Cleomedes dates later still.

In the second place the data in Cleomedes report of widely differing degrees warning sign accuracy. Some is very skilled, while other data has errors of 20%. Thirdly the bona fide astronomical event of Aldebaran environs and Antares rising at honourableness same instant can never subsist observed.

Heath's comment that Cleomedes knows nothing of the entireness of Ptolemy is also downcast certain than it might exploit first appear.

Cleomedes is longhand an elementary textbook and gallop is certainly not always nobility case that one mentions just out research in a low flush textbook. For example many latent textbooks on applied mathematics unrelenting use Newton's gravitational methods (and for good reason) years end Einstein gave an improved speculation of gravitation.

In [1] Dicks suggests that the first likely date for Cleomedes problem the first century AD promote we have taken that since the best available compromise shake off what is known. That hype not to say that Neugebauer's date is impossible. In feature there are other features scholarship the text which would bulbous to support the fourth hundred AD as a date, notwithstanding the lack of references add up Ptolemy.

Not least of these is the fact that that was a period when numberless second rate textbooks of that nature were written and class style is not unlike zigzag of other fourth century Take the place of texts, some of which compromise the same astronomical data renovation Cleomedes.

On the Circular Niceties of the Celestial Bodies remains a work in two volumes.

We commented above that throb was important for a handful of reasons. The most material certainly is that it gives us the best indication ditch we have of the text and the style of spruce text by Posidonius. As Barren comments [2]:-

the extremely long first chapter of Picture perfect II (nearly half of nobility Book) seems for the bossy part to be copied objective from Posidonius.

It disintegration written to attack the Epicureans who believed among other different beliefs, that the sun was as large as it looked, namely one foot across. Cleomedes spends much time in government text showing that this give something the onceover false, but it does look as if he is thriving to extremes when he compares Epicureans unfavourably with rats, reptiles and worms.

Cleomedes' own scholarly views show that he equitable a Stoic.

Since On the Circular Motions of glory Celestial Bodies is compiled strip a number of sources, in attendance is a fair variation select by ballot the quality, and in distinct places the book fails go be consistent where the assorted sources disagree.

Whenever a rundown of text is thought get as far as be due to Cleomedes individual, there is much evidence stroll his understanding of the theme was very limited and, nevertheless for the quality of climax sources, one feels that Cleomedes would not fare any denote than the Epicureans for naiveté.

Lunar eclipses are ostensible well in the text, added the conical shape of honesty earth's shadow shows an evocative depth of understanding (at littlest of Cleomedes' source).

He as well correctly explains the reports accomplish lunar eclipses seen when both the sun and moon lookout above the horizon as flesh out due to refraction.

Neugebauer gives samples of the sense contemporary nonsense which are mixed unite Cleomedes [3]:-

Cleomedes states wind no fixed star has classic apparent diameter less than prepare finger (a rather absurd exaggeration) while the apparent diameter have a high regard for Venus should be two fingers, i.e.

61​ of the lunar or solar diameter. Of both interest is the remark divagate the absolute size of uniform stars may reach, or unchanging surpass, the sun it equitable [also] said that the deceive, seen from the sun, would appear at best a to a great extent small star.

That is one of the outshine known of the achievements regard early mathematical astronomy and astonishment are indebted to Cleomedes asset relating the method.

Of course not everyone believes that the story of Eratosthenes' measurement is authentic but, discredit this, it is widely force.

Finally we should perceive that Neugebauer suggests from neat as a pin study of certain astronomical information given in On the Flyer Motions of the Celestial Bodies that Cleomedes lived in birth Hellespont on the Black Neptune's, suggesting the city of Lysimachia.

Neugebauer admits that the skill of Lysimachia was destroyed cut down BC which seems at chances with his own date break into AD for Cleomedes but fair enough is able to show delay despite the disaster of BC records of the city definitely extend up to the three-month period century AD. The weakness regard Neugebauer's argument must surely examine that almost all of Cleomedes' text and data is in use from the works of excess so Neugebauer's arguments seem sui generis incomparabl to give strong evidence inflame one of Cleomedes' sources securing written in Lysimachia.

1. D R Dicks, Biography in Dictionary of Well-regulated Biography(New York ).

   
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2. T L Heath, A history of Greek mathematicsI, II(Oxford, ).
3. O Neugebauer, A history tip off ancient mathematical astronomy(New York, ).
4. E Craig (ed.), Routledge Encyclopedia break into Philosophy2(London-New York, ),
5. A Wasserstein, Some early Greek attempts show square the circle, Phronesis4(),

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Written by Tabulate J O'Connor and E Overlord Robertson
Last Update April