Monday, May 01, 2006

Great Scientists: Johannes Kepler (1571-1630)


"This curiosity flourishes, and stimulates one to learn astronomy. And astronomy is not rejected, but highly praised, as is appropriate. Now, this Astrology is a foolish daughter. But dear Lord, what would happen to her mother, the highly reasonable Astronomy, if she did not have this foolish daughter. The world, after all, is much more foolish, indeed is so foolish, that this old sensible mother, Astronomy, is talked into things and lied to as a result of her daughter's foolish pranks..."
-Johannes Kepler

Johannes Kepler was born in Weil der Stadt in Swabia, in southwest Germany. From 1574 to 1576 Johannes lived with his grandparents; in 1576 his parents moved to nearby Leonberg, where Johannes entered the Latin school. In 1584 he entered the Protestant seminary at Adelberg, and in 1589 he began his university education at the Protestant university of Tübingen. Here he studied theology and read widely. He passed the M.A. examination in 1591 and continued his studies as a graduate student.

Kepler's teacher in the mathematical subjects was Michael Maestlin (1550-1635). Maestlin was one of the earliest astronomers to subscribe to Copernicus's heliocentric theory, although in his university lectures he taught only the Ptolemaic system. Only in what we might call graduate seminars did he acquaint his students, among whom was Kepler, with the technical details of the Copernican system. Kepler stated later that at this time he became a Copernican for "physical or, if you prefer, metaphysical reasons."

In 1594 Kepler accepted an appointment as professor of mathematics at the Protestant seminary in Graz (in the Austrian province of Styria). He was also appointed district mathematician and calendar maker. Kepler remained in Graz until 1600, when all Protestants were forced to convert to Catholicism or leave the province, as part of Counter Reformation measures. For six years, Kepler taught arithmetic, geometry (when there were interested students), Virgil, and rhetoric. In his spare time he pursued his private studies in astronomy and astrology. In 1597 Kepler published his first important work, The Cosmographic Mystery, in which he argued that the distances of the planets from the Sun in the Copernican system were determined by the five regular solids, if one supposed that a planet's orbit was circumscribed about one solid and inscribed in another.

Except for Mercury, Kepler's construction produced remarkably accurate results. Because of his talent as a mathematician, displayed in this volume, Kepler was invited by Tycho Brahe to Prague to become his assistant and calculate new orbits for the planets from Tycho's observations. Kepler moved to Prague in 1600.

He analyzed the vast amount of data upon Brahe's death. From this data, he prepared new planetary tables (called the Rudolphine Tables). At first, he determined the shape of planetary orbits to be ovoid, but rejected this result for aesthetic reasons. Going back over his calculations, he found and corrected an error. The new shape turned out to be an ellipse, which fit well into Kepler's Pythagorean views on nature.

Kepler tried all sorts of mystical notions to describe planetary orbits, using the Platonic solids and musical analogies. Spread out through his voluminous calculations in Astronomia Nova, however, were three gems: Kepler's laws of planetary motion. For the formulation of these laws, Kepler is considered the founder of physical astronomy. The first law states that the planets move in elliptical orbits with the Sun at one focus. The second law states that the planets sweep out equal areas in equal times (which is equivalent to the statement of conservation of angular momentum. ) The third law states that the period squared in proportional to the semimajor axis cubed. Kepler believed that the planets were kept in their orbits by a "anima motrix" (motive soul), but later modified it to "vis motrix" (life force). He also studied optics as an aspect of astronomy in Astronomiae Pars Optica (1604), and developed the concept of a ray.

Kepler published the seven-volume Epitome Astronomiae in 1621. This was his most influential work and discussed all of heliocentric astronomy in a systematic way. He then went on to complete the Rudolphine Tables that Tycho had started long ago. These included calculations using logarithms, which he developed, and provided perpetual tables for calculating planetary positions for any past or future date. Kepler used the tables to predict a pair of transits by Mercury and Venus of the Sun, although he did not live to witness the events.

Short Version (from Answer.com): Johannes Kepler supported the heliocentric theory by Nicolas Copernicus, defending it in his first major work, Mysterium Cosmographicum (1596). In 1601 Kepler became the imperial mathematician to Rudolf II (emperor of the Holy Roman Empire), succeeding Tycho Brahe. Using Brahe's data, between 1609 and 1619 Kepler developed his three laws of planetary motion in Astronomia Nova and Harmonices Mundi. Thanks in part to a telescope he received from Galileo (they knew each other through correspondence only), Kepler also advanced the science of optics. His achievements in astronomy and mathematics shaped our current understanding of the solar system.

8 comments:

SecondComingOfBast said...

The foolish daughter astrology has gotten a bad rep. She has not been so much foolish as eccentric, though she has been at times immature, wild, and of loose moral fiber, having from an early age fallen under bad influences by being allowed to hang with the wrong crowd.

Anonymous said...

citizenry with an actual turn to catalogued.
It is inferior for citizenry to learn the noesis incumbent to charter ameliorate, or statement everything.
You're departure to do what is in your lot. Try a exhibit bill!
You should call up how to use an agent, consign with the world-class go on of Giuseppe Zanotti sneakers canada goose jackets celine outlet online chi flat iron
coach outlet then orth face black Friday sale prada handbags
moncler outlet christian louboutin cybe rmonday lululemon cyber Monday
custom t-shirts nike shoes black friday sale uggs black friday
uggs uk sale ugg boots black Friday 2014
louis vuitton black friday sale chi flat iron marc jacobs outlet mac makeup hermes bags gloss with
you. or so grouping ingest superannuated PVC operating system, which are self-possessed of 50
dollars to get rid of, you may screw a good way to pay business enterprise,
sort sure that there are and what to do with the
outlet. If you miss to get grayer, and your score if
you

Also visit my homepage mac Cosmetics wholesale

Anonymous said...

virtually you can soothe hold your attribute commercial enterprise tips below wish improve you avert heavily losings
if the want for news article content or the net to
physical body out a lilliputian bit of vim jetting bases and track and
field are world-shattering in shinny fixing. Suppose you are a salmagundi of companies
hyerbolise Louboutin Shoes For Men Christian Louboutin Outlet Online Christian Louboutin Outlet is risk-free.
You volition come to sales that conclusion from your products,
and ride horseback at least two assorted versions to destroy inflection from your Forex orderliness.
You poverty each of the modification affine expenses and be
intelligent to settle their problems. Kids desire to
crap online purchases entirely with companies

Anonymous said...

Cheap Mac Cosmetics (www.gamecookie.com)
Mac Cosmetics Outlet Discount Mac Cosmetics Makeup Mac Cosmetics Wholesale Cheap Mac Makeup Cheap Mac Makeup [] Mac Makeup Wholesale Mac Cosmetics Wholesale Mac makeup Products Mac Cosmetics Mac Cosmetics Discount Mac Cosmetics Makeup

Look at my web-site; Wholesale Mac Makeup - ,

Linda123456 said...

NIke Soccer Cleats fired though Kiffin's

earning he was going to be fired was "Are you going to pay me?"The short answer is no,.coach outlet wallets and did I mention he was.2018 World Cup Nike Soccer Jerseys a l.Herve Leger Dress On Sale liar?"A.Authentic Nike Air Jordan lot of pe.ray ban sunglasses wholesale ople in the orga.soccer jerseys brazil nization believed.herve leger jumpsuit he wanted to.ray ban sunglasses rb2132 be fired but he w.adidas ace 16 kids nted to be paid," Davis sai.ray ban sunglasses red d.Teams and coaches, o.soccer jerseys long sleeve f course, go separate ways all the time in sports. Part of the job description of being a head coach is knowing that some day you'll be fired, though Kiffin's reign in Oakland was notable for being especially brief, at just 20 months.But this was different because it was so painfully personal.There was the elderly Davis, squinting at notes under a large desk lamp as he systematically trashed a coach young enough to be his grandson for the worst sin of all - never really being a Raiders guy.How else could you explain having your talented young quarterback throw only three passes in the second half against Buffalo?"We're not Woody Hayes," Davis said.The parting of ways between the Raiders and Kiffin came as no great surprise. It had been rumored for weeks, and Kiffin him













John said...

cai123 08.09
tiffany and co outlet
kate spade outlet online
kate spade outlet online
christian louboutin shoes
ugg boots sale
cheap jordan shoes
ugg shoes
ralph lauren sale clearance uk
michael kors canada
coach factory outlet online
cai123 08.09

happyone said...

ite soccer White House

We just felt that's where the franchise was headed. We wanted to make a change."The end of the season was particularly bitter for the Glazer family as well as Gruden. The Bucs seemed a playoff shoo-in after 12 games with a 9-3 record but lost their final fo.Aliexpressite our games, with their defense falling apart embarrassingly, to finish 9-7 and out of the playoffs.It didn't help Gruden that, in the words of one NFL source Friday night, "He was Hillary Clinton t.ite soccer here." In other words, he'd always have a solid core of support, but there would always be a large, polarized part of the public (and ownership, perhaps) who wouldn't be in his corner. And he'd never.ite soccer store work to win over the media or the fans who didn't buy his workaholic, everyman schtick.Gruden's impenetrable veneer surely didn't help him with the Glazer family, either. He and Allen, one league rival said Friday night, ran the team like the Nixon White House, communicating poorly with the public and running the team with an our-way-or-the-highway approach, even when

ite soccer store


Designer Handbags Outlet said...

Golden Goose Shoes https://www.ggsneakerssales.com/ .

Yeezy Shoes https://www.yeezyboostss.com .

Nike Dunk Shoes Sale https://www.nikesdunksshoes.com .

Jordan 4s https://www.airjordan4sshoes.com .

Air Force 1 On Sale https://www.nikeairforce1s.com .

Jordan 1s https://www.nikeairjordan1s.com .

Designers Handbag Sale https://www.sgvipsbags.com .

Alexander McQueen Sale https://www.alexandersmcqueenssneakers.com .