The Starry The Starry MessengerMessenger

What was it?•A 56 PAGE SCIENTIFIC TREATISE released in 1610, in Latin.• A report on new exciting discoveries of the ‘spyglass’•DEDICATED TO THE FOURTH DUKE OF TUSCANY, COSIMO MEDICI I, HIS PATRON.•Written rather quickly to assure his fame

What does it contain?• 1: His claim to the

creation and understanding of the telescope and a description of it

• 2: the surface features of the moon revealed by his new discovery, such as craters and mountains “higher than mountains on earth”.

• 3: The resolution of new fixed stars.

• 4: the resolution of the milky way and some nebulae, such as Orion, into individual stars.

• 5: the detailed observation and charting of the most visible 4 moons of Jupiter. [1]

Why was it important?• First ever scientific treatise addressing the telescope;

the future of observational astronomy. • The use of scientific method –his work was testable.• The first documented observation of another planet’s

moons.• The idea that nebulae could consist of stars.• An example of the scientific application of telescope.• The definite moment in the undermining of the

Ptolemaic system, eg. Jovian moons, Gegenschein; “One look through the telescope, and a reasonable man would start thinking”[2]

OTHER WRITINGS* The Little Balance (1586) – his own theories based on Archimedes law of leverage and the

law of buoyancy * Letters on Sunspots (1613)

* Letter to Grand Duchess Christina (1615) – an essay on the relation of the new discoveries in science to revelations and biblical quotation

in the bible * discourse upon Comets (1619) DISCORSO DELLE COMETE – a critique of orazio grassi’s

“on the 3 comets of 1618” delivered in a lecture at the florentine academy by June

Mario Guiducci, a pupil of Galileo's.

• The Assayer (1623) Il Saggiatore – a second critique on a jesuit astronomer, orazio gracci, who correctly believed that comets where ‘real’ and moved beyond the orbit of the moon.

• * Dialogue Concerning the Two Chief World Systems/ (1632) Dialogo dei due massimi sistemi del mondo – the scientific comparison which touted the copernican as a legitimate alternative to the ptolemaic system, and attacked members of the papacy in metaphor.

• * Two New Sciences (1638) Discorsi e Dimostrazioni Matematiche, intorno a due nuove scienz – Published in Leiden,

Holland, as galileos' works were

banned in italy. It contained no cosmology and dealt instead with the engineering science of resistance and material strength, and the mathematical science of motion and acceleration. It was considered by many to be his ‘magnum opus’. [3]

• “In my Starry Messenger there were revealed many new and marvelous discoveries in the heavens that should have gratified all lovers of true science” – 1623; letter written to Don Virginio Cesarin [4]

• [1],[2] http://isc.temple.edu/pericles/forster.htm [accessed 21/1/08]

• http://www.physics.emich.edu/jwooley/chapter9/Chapter9.html [accessed 21/1/08]

• http://www.sparknotes.com/biography/galileo/section5.rhtml [accessed 21/1/08]

• [3] http://physics.ship.edu/~mrc/pfs/110/inside_out/vu1/Galileo/galileo_timeline.html [accessed 21/1/08]

• [4] http://www.chlt.org/sandbox/lhl/dsb/page.245.php [accessed 21/1/08]

• TRANSCRIPT: http://www.liberliber.it/biblioteca/g/galilei/sidereus_nuncius/html/sidereus.htm [accessed 21/1/08]