Galileo and the language of science

Galileo's observing notes for 1610 begin in Italian. Clearly he is writing little memos for his own interest. He discovered the moons of Jupiter on 7 January 1610 he switched to Latin after 12 January. Latin of course was the language used by all savants, natural philosophers, and mathematicians until the end of the 18th century. Copernicus, Mewton, and Descartes wrote in Latin in order to reach an international audience. Galileo wrote books in Italian and Latin. For example, the famous Dialogue of the Two World systems, published in 1632, and which directly led to his trial in 1633, was Italian because he wished to reach a wide lay audience in his home country. The Starry Message (Sidereus Nuncius) published in 1610 is in Latin because it contained revolutionary ideas, and he wanted to reach an international readership of natural philosophers. In terms of the history of science communication, Galileo is remarkable because he writes popular stuff in Italian and serious stuff in Latin

For a modern take on communicating the new astronomy to a variety of audiences see http://bit.ly/TOTast

Interested in Sidereus Nuncius? Buy it here

Galileo has observed Jupiter's moons for two weeks

400 years ago tonight marks the first two weeks of Galileo's observations of Jupiter's four moons. By now he has seen the moons play hide and seek many times -- going into and emerging from eclipse by the giant planet Jupiter. He is absolutely convinced that the moons are part of Jupiter's system. However, in his observing notes he is not yet speculating about what his observations indicate. He's demonstrating great restraint. His notes show excellent observation of the application of the scientific method: observe, acquire data of the highest quality, write it all down

My website for Total Astronomy media services

Galileo sees all four again

15 January 1610. Galileo can't wait for evening twilight. He was clouded out last night, but tonight, three hours after sunset, he points his spyglass at Jupiter once again and sees all four of the companions, all to the west of Jupiter. Four hours later ('the seventh hour', after midnight) the visible companions are three in number. He stays up another hour and spies two of the companions in conjunction

I keep having toremind myself that the diagrawms in Sidereus Nuncius are the telescope view, which is inverted -- east is right and west is left in Galileo's thumbnails

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Galileo sees four moons for the first time

Yesterday, minus 400 years, on 13 January 1610, Galileo saw all four moons of Jupiter for the first time. He wrote that all four were of the same magnitude and far outshone the background field stars

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Galileo sees a star 'appear' while observing Jupiter

So the next night, 400 years ago tonight, Galileo looks at Jupiter one hour after sunset. He can see two bright stars parellel to the ecliptic, one east of Jupiter and one to the west. A couple of hours later he spies a third object, quite dim, 'almost touching Jupiter'. By now he realises that he is making a discovery of momentous importance

He gets a new surprise the next day.

Stay tuned by following this blog. I will be covering Galileo's observations through to early March 1610. All blogs will be concise. Comments on the blog aare most welcome


Simon Mitton
http://bit.ly/TOTast

Galileo realises that he has discovered worlds orbiting Jupiter!

Exactly 400 years ago tonight* Galileo sees two stars to the east of Jupiter, one of which is twice as bright as last night. This is the night on which he is amazed to accept that the only explanation of his observations is "I have now accepted without the shadow of doubt that there were in the heavens three stars wandering about Jupiter, just as Mercury and Venus go round the Sun"

That folks is truly awesome. Having observed Jupiter on just four nights he reaches the correct conclusion that the Copernican system applies to Jupiter just as it applies to the Sun

Source of this information is a new translation of Sidereus Nuncius http://bit.ly/7WsibK

Editors, producers, media folk etc can contact me through my website http://bit.ly/TOTast

Galileo is now completely baffled

So, last night, 9 January 1610, Galileo was clouded out. 400 years ago tonight it was clear in Venice, so he turned his 20x power spyglass to Jupiter once more. He can see only two starlets! One has disappeared or is hiding. At this stage he cannot figure out what's happening. Remember, he has only three observations, and his telescope does not have setting circles or anything fancy like that. With three observations spanning just four nights he cannot yet rule out the weird possibility that there is something irregular about Jupiter's motion, an irregularity that would not be detectable to a naked eye astronomer. He's also intrigued by the fact that these unpredictable starlets are on a line parallel to the ecliptic. He actually calls them big stars because they seem so bright through his telescope.

Media industry and other followers can contact me through my website http://bit.ly/TOTast

I have an interview about Galileo's discoveries of 1610 with BBC Radio 4 coming in February. I am interested in further commissions / talks / science writing

Galileo gets clouded out!

So having spied three starlets close to Jupiter, Galileo was anxious totake another peek on this date, 9 January, exactly 400 years ago today. But he was disappointed --clouded out. It happens to us all. I have been clouded out at three total solar eclipses. Stay tuned for tomorrow-- the starlets are playing hide and seek

Links: follow the links in yesterday's blog

Galileo asks: did Jupiter move east last night?

On 8 January 1610 Fate compelled Galileo to take his second look at Jupiter. This time all three little stars were west of Jupiter, whereas the night before two of them were east of Jupiter. That riased a huge question in his mind: Had Jupiter moved eastwards since the 7 January? Such a proper motion would be entirely at odds with the computations of astronomers.

My source is a new translation of Sidereus Nuncius http://bit.ly/7WsibK

Media followers, editors, etc can find me at http://bit.ly/TOTast

Galileo: 400th anniversary Moons of Jupiter

Exactly four hundred years ago today (ignoring the effect of calendar reform) Galileo first spied three stars close to Jupiter: two to the east and one to the west. On his first sighting he could not, of course, note anything unusual (his telescope could see millions of stars), but they caused him surprise because they were in a straight line parallel to the ecliptic.

Come back tomorrow to see what happened next!

Links and acknowledgement can be found on blogs below

Galileo: seeing stars to magnitude 12

In Sidereus Nuncius (1610), Galileo writes that his telescope allows him to see a further six orders of magnitude. The Greek astronomer Hipparchus devised the magnitude system in about 150 BC. The brightest stars were first nagnitude and the faintest visible to the naked eye sixth magnitude. A first magnitude star emits 100 times the light of a sixth magnitude star. Ptolemy uses this convention in the Almagest.

Galileo's telescope showed stars frommag 7 to mag 12. The light from a mag 12 stars is 10,000 times fainter than mag 1. Galileo described the 7 - 12 mag stars as "so numerous they are almost beyond belief.

Source of this information: follow the links in yesterday's blog

Galileo gets a pay rise

On 24 August 1609, just over 400 years ago, Galileo visited the Ducal Palace in Venice to present a spyglass (telescope) to the Doge. At this date Galileo has yet to turn his telescope to the heavens. His accompanying letter assigned the copyright to the Venetian Republic. He explained that the spyglass could be used tosee approaching enemy boats at muchgreater distance thanbyeye alone, allowing more time "for engagement, pursuit or flight".

The chairmanship of the Venetian Senate rotated weekly. One of Galileo's chums had the chair that week. In 1608 he had the University of Padua increase Galileo's salary from 160 florins to 320 florins a year payable in advance. On 25 August this influential supporter, Antonio Priuli, had the Senate grant Galileo tenure for life, and an increase in salary from 320 florins to 1000 florins, the highest salary the university ever paid to a professor of mathematics

My source of this information http://bit.ly/7WsibK

Media followers who would like help to cover Galileo's discoveries of 1610 can contact me via http://bit.ly/TOTast

Galileo resolves misty nebulae into stars 1610

In his stunning book A Sidereal Message (actual title is Sidereus Nuncius, normally translated incorrectly as The Starry Messenger)Galileo lists eight telescopic discoveries,anyone of whichwould have earned the Nobel Prize established some 300 years later!

Philosophers had long puzzled over structures in the universe that had the title 'nebulous stars' by the early seventeenth century. The word nebulous does not mean insterstellar matter (that use had to wait for William Herschel), but meant cloud like. Claudius Ptolemy, in the Almagest lists seven of these, which Galileo examined using a 20X power Galilean telescope.

He resolved them in numerous faint stars. In the head of Orion he found 27 stars, and in Praesepe 40 stars

My source of this information http://bit.ly/7WsibK

Media followers who would like to cover Galileo's discoveries of 1610 cancontact me via http://bit.ly/TOTast

Galileo and the Moon Sidereus Nuncius

Here's what Galileo wrote 400 years ago this month to describe the Moon:

He used a telescope that magnified 20 times

"The observational evidence is so compelling that anyone can grasp for himself that the moon's surface is not smooth and polished but rough and uneven. Like the Earth it is covered all over with huge bumps, deep holes, and chasms" He went on to provide sketches of the terminator, showing large craters and high mountains.

Five years later, on 28 February 1615 he received a sharp letter from a high officer of the Vatican warning of the dangerous speculation arising from his claims, namely that the Moon had similarities to Earth.

My source of this information http://bit.ly/7WsibK

Galileo and the Milky Way Sidereus Nuncius

Galileo wrote this, 400 years ago in 1610:

"What we observed in the third place is the essence, namely the matter, of the Milky Way, which can be seen so clearly with the aid of the telescope that what philosophers found for centuries an excruciating problem has been solved with ocular certainty thus freeing us from wordy disputes"
From http://bit.ly/7WsibK

Aristotle maintained that the Milky Way was a celestial fog