The index:
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 Introduction
page 2
 Ptolomaeus
page 3
 Keppler
page 4
 Tycho Brahe
page 5
 Galileo Galilei
page 6
 Copernicus
page 7
 The End
page 8
Introduction:
The renaissance changed everything in our life. Without the renaissance our life would be like
in the middle Ages. There are a few main people, Galileo Galilei is one of them, I will talk
about him in my essay, but I will also talk about other main renaissance people. What started
this rebirth (translation for renaissance)? And who changed it? That’s where my essay is all
about!
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Claudius Ptolomaeus was a Greek astrologer, astronomer, geographer, mathematician and a
music theorist. He lived in Alexandria. As an astrologer he wrote 4 books about the stars
known as Tetrabiblos. In this book it’s mostly about Horoscopes. Ptolomaeus had great
influence in the astrology. Many of his ideas are still used by great astrologers today. As an
astronomer he made an egocentric image of the solar system. Known as the ‘system of
Ptoleomaeus’. But he might be best known for his ‘Cosmographia of Geographia’ a guide for
making cards. During the renaissance there were many interests in this Geographia. Before
1600 there where 31 Latin or Italian editions made, these formed the first atlases.
This is Ptolomaeus.
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Johannes Keppler was a mathematical genius and a German astronomer. Tycho Brahe
looked at the way the planets move in the sky, this motion is very complex. But Keppler
found a simple way to say how the planets move. Keppler and Brahe worked together to find
the data they needed to explain the truth. Brahe died first so Keppler explained what was true.
The three rules of Keppler:
1. Planets don’t move in circles, they move in ellipse.
2. The closer the planet is to the sun, the faster it moves.
3. A year is the time it takes for a planet to go around the sun. The closer the planet is to the
sun, the shorter the year is. Year² = Radius ³
This is Johannes Keppler
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Tycho Brahe was a noble man from Denmark. He discovered a new bright star in the
constellation Cassiopeia. He described this in his book the Stella Nova. This discovery made
him very famous.
The king of Denmark gave Tycho Brahe an observatory to explore more about the universe
and the planets. This observatory was build on the island Hven, he got money to build two
observatories, one called Uraniumburg, the other called Stjerneborg. And so on Tycho Brahe
continued his observation. Later Keppler became his assistant and took over when Tycho
Brahe died.
This was his observatory
now, it’s a museum.
This is Tycho Brahe
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Galileo Galilei was an Italian physicist, an astronomer, a mathematician and a philosopher.
He liked the ideas of Copernicus. Galileo was the first one to publish a telescope with two
lenses, one very strong one, and one very weak lens. So you magnify the one object, and than
magnify it more and more. He also discovered a lot about planets, the solar system, the
universe and the Milky Way. He found out that Venus has light and dark phases, just like the
moon. This helped to prove that the sun is the centre of the solar system, as Copernicus said.
Galileo also studied natural forces, and other things called principles of physics. He found out
that, when you drop two balls with different weight down, they hit the ground at the same
time. This went against the ideas of Aristotle. But Galileo’s idea was ignored until Isaac
Newton proved it was true. He also tried to estimate the speed of light, however this did not
work.
This is Galileo Galilei
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Nicolaus Copernicus was best known for his ideas about the sun and the earth. His main idea
was that our earth is Heliocentric (helio = sun). His theory was that the sun is in the middle of
our solar system and that the planets move around it. So he said that planets move around the
sun and not around the earth, what was thought in that time. He wrote this idea down in his
book ‘On the revolutions of heavily bodies’ (The revolutionibus orbium coelestium).
Copernicus was one of the great polymaths of his age. He was a priest, mathematician,
astronomer, doctor, jurist, physician, classical scholar, governor, administrator, diplomat,
economist, and soldier. During all these jobs, he treated astronomy as a hobby. However, his
formula of how the sun, rather than the earth, is at the center of the solar system was one of
the most important scientific hypotheses in history. It was the beginning of modern
astronomy.
This is Copernicus
The end
So, now you have read my essay about physics in the renaissance, actually more ‘people who
created physics in the renaissance’ all these people, from Ptolomaeus to Copernicus changed
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life during the middle ages. Without these people, we wouldn’t have known a lot of things
about our universe and stuff. They changed our world, they changed life’s.
I think this essay was a great way to learn more about physics and more about the renaissance.
I really enjoyed making this essay because I found some very new things about these people.
Off course I heard about their names, but now I know a lot more about them and what they
changed. Sometimes it was difficult though, I found it especially difficult to start because I
didn’t know how. But after a while thinking ideas come up in your mind and you just start
writing and 2 hours later you have your essay.
This was my essay; I hoped you enjoyed reading it!
Anouk Harting
TT2L
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