Many of you already know me that I sit at the back on Tuesdays in the lectures and ask

stupid questions at the end.

Today I'm standing at the front, which means you have the chance to ask stupid questions

and I have to answer them.

This as you will see is actually supposed as a partial presentation of this book, Seymour

Marison's research, which appeared this year, which in itself is an expanded version translation,

English translation of a German book which appeared in 2015, which was an expanded version

of a conference which took place in 2014 in Nuremberg to celebrate the 400th anniversary

of the Magnum Orbis of Seymour Marius, which I'll talk about later.

This throws up the question, why Seymour Marius?

Why should a lot of partially very famous historians take an interest in a rather obscure

Franconian mathematician, astrologer, astronomer?

The answer to this question is a strange quirk in the history of astronomy, or the initial

answer to this question is a strange quirk in the history of astronomy.

On 7th January 1610 Galileo Galilei, with a relatively new instrument, the telescope,

the star Galilei made its first discovery of three of the four largest moons of Jupiter.

This is the recording, this is the notes that he made on the occasion, these are the three

moons labelled before.

You can actually see them here, this is a modern picture of Jupiter in its four largest

moons which are mostly called these Galilean moons, named after Galileo of course.

The strange quirk is that on 8th January 1610, one day later, Seymour Marius made the same

discovery.

This is not actually quite as strange as it seems.

As often in the history of science, people were pointing telescopes at the sky, all of

the discoveries for which Galileo is famous were made either before Galileo or simultaneously

or in the same time period by other people pointing telescopes at the sky, but mostly

history says Galileo discovered it all.

Just to take a simple example, the sunspots were first discovered by Thomas Harriot, they

were first published by Johannes Fabritius and so forth.

Galileo gets the credit for being the first to discover with telescope sunspots which

are complete rubbish.

So this is not that strange.

We then ask what happened next was that two months later Galileo published what is probably

one of the most famous books in the history of astronomy, Sidereus Nuncius, which announces

his discoveries that he made with his telescope.

It was an absolute sensation.

He went overnight from being an obscure Middle-Age North Italian professor from mathematics

to being the most famous astronomer in the world.

And we have here one of the pages from the Sidereus Nuncius which shows his observations

of Jupiter and its moons.

Simon Marius waited four years.

This is Magnum Orbis, the one of the Sylviares, which was first published in 1614, as they

say 2014 we celebrated the 400th anniversary of this publication, which led to not directly

but in 1623 in Il Sagatorium, the Açaea, Galileo had sort of attacked all of his supposed

enemies.

And he accused Marius of plagiarism.

And the accusation stuck.

And it was first at the end of the 19th century, beginning of the 20th century, that a Belgian

academic society investigated the case, looked at the things, and established that Marius's

observations were independent of those of Galileo.