Katalin Radnóti Eötvös Loránd Univesity [email protected] The Copernican revolution

KatalinKatalin RadnótiRadnótiEötvös Loránd Univesity Eötvös Loránd Univesity [email protected]@helka.iif.hu

The Copernican The Copernican revolutionrevolution

The Copernican revolutionThe Copernican revolution

Aim of the modul:Aim of the modul:

The show the way of science, The show the way of science, experience and ideas.experience and ideas.

• How does science operate? How does science operate? • What are its values? What are its values? • How valid are its conclusions?How valid are its conclusions?


We will look at a historical example: We will look at a historical example: the early history of astronomy. the early history of astronomy.

This is the This is the genetic waygenetic way of learning. of learning.

1. 1. ActivityActivity On a clear night, follow the stars On a clear night, follow the stars

across the sky. Look at the across the sky. Look at the MMoon, the oon, the North Star and any group of stars ect. North Star and any group of stars ect. Describe your observations.Describe your observations.

The Copernican revolutionThe Copernican revolution From such observations, most people would From such observations, most people would

conclude that the stars, conclude that the stars, SSun, un, MMoon, and planets all oon, and planets all are moving in circles around Earthare moving in circles around Earth..

This is the conclusion most observers drew This is the conclusion most observers drew centuries ago. centuries ago.

The observations and conclusions The observations and conclusions described here are typicals of science’s described here are typicals of science’s two main process: two main process:

observingobserving, , and conceptualizing or makingand conceptualizing or making

theoriestheories..


2. 2. ActivityActivity The children make The children make

up the up the earliest earliest GreekGreek model of the model of the universe.universe.


ProblemProblem Mars even changes Mars even changes

directions and moves east directions and moves east to west relative to the to west relative to the stars, this is stars, this is retrograde retrograde motionmotion..

AristarchusAristarchus PtolemyPtolemy3. 3. ActivityActivity The children make up The children make up

Ptolemy’s model of the Ptolemy’s model of the universe.universe.


Copernicus’s theory:Copernicus’s theory: a a SSun-centred universeun-centred universe

1543.1543. He found a more He found a more

reasonable reasonable arrangement of circlesarrangement of circles..

TThe natural heavenly he natural heavenly motions were both motions were both circular.circular.


Both theories agreed with the data.Both theories agreed with the data.

But there were a lot of questions:But there were a lot of questions:

How can Earth move?How can Earth move? What keeps it moving?What keeps it moving? Why aren’t birds and clouds left behind?Why aren’t birds and clouds left behind? Why aren’t objects hurled off Earth?Why aren’t objects hurled off Earth?

The answer The answer waswas in Newton’s physics. in Newton’s physics.


4. 4. ActivityActivity The children make up Copernicus’s model of The children make up Copernicus’s model of

the universe.the universe.

5. 5. ActivityActivity When we say that the When we say that the SSun „rises”, what do we un „rises”, what do we

mean,mean,

a.a. from the Copernican point of view,from the Copernican point of view,

b.b. and from the Ptolemian point of view?and from the Ptolemian point of view?


6. 6. ActivityActivity Use Copernicus’s Use Copernicus’s

theory to explain theory to explain retrograde motion.retrograde motion.


GalileGalileii introduces the telescope into introduces the telescope into astronomy. He observed that Venus astronomy. He observed that Venus goes through phases goes through phases similarsimilar to the to the MMoon’s phases.oon’s phases.

7. 7. ActivityActivity Use Copernicus’s theory and Ptolemy’s Use Copernicus’s theory and Ptolemy’s

model to explain the phases ofmodel to explain the phases of the the Venus. WVenus. With with which of them hich of them are you are you able able to explain the to explain the full full phase of phase of the the Venus?Venus?

The phases of the VenusThe phases of the Venus


Would Brahe’s measurements be able to Would Brahe’s measurements be able to distinguish between them and so determine distinguish between them and so determine which onewhich one was correct? For the next 20 years, was correct? For the next 20 years, Brahe catalogued accurate data on the positions Brahe catalogued accurate data on the positions of the of the SSun,un, the the MMoon, andoon, and the the planets. His planets. His measurementmeasurementss w weere re more accuratemore accurate, than , than the the earlier data. earlier data.

The result was, thatThe result was, that neither neither Ptolemy’sPtolemy’s Earth- Earth-centred theory centred theory nornor Copernicus’s Copernicus’s SSun-centered un-centered theory agreed with Brahe`s data. theory agreed with Brahe`s data.

The Copernican revolutionThe Copernican revolution Brahe`sBrahe`s catalogue catalogue waswas the key for the key for KeplerKepler.. Now calles Kepler`s three laws, discribing the Now calles Kepler`s three laws, discribing the

planetary orbits. planetary orbits. The most significant lThe most significant laaw states that rather than w states that rather than

moving in moving in SSun-centered circles, each planet un-centered circles, each planet moves in a moves in a SSun-focused un-focused ellipseellipse. .

8. 8. ActivityActivity Together with members of your class, lay out the Together with members of your class, lay out the

scalemodel of the scalemodel of the SSolar olar SySystem. Begin with a stem. Begin with a ball to represent the ball to represent the SSunun,, tthen lay out the nine hen lay out the nine objects to represent the planets.objects to represent the planets.

Kepler’s lawsKepler’s laws

The Copernican revolutionThe Copernican revolution Kepler`s theory dKepler`s theory didid moremore than describe known than describe known

data. It also data. It also predictpredicteded new observations new observations that that were unknown to Kepler. For example, when were unknown to Kepler. For example, when new planets (Uranus, Neptunus, Pluto) were new planets (Uranus, Neptunus, Pluto) were discovered. discovered.

Kepler`s theory is able to suggest further Kepler`s theory is able to suggest further developments. developments.

Newton made important use of Kepler`s theory Newton made important use of Kepler`s theory in his theories of force, motion, and gravity. in his theories of force, motion, and gravity.

Without Kepler Newton`s more sweeping Without Kepler Newton`s more sweeping theories would have been impossible. theories would have been impossible.

Newton could Newton could unify the heavens and Earthunify the heavens and Earth..

Thank you for your kind Thank you for your kind attentionattention

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Katalin Radnóti Eötvös Loránd Univesity [email protected] The Copernican revolution