WALT express significant figures' views on the different models of the universe.
What do you remember about Ptolemy's theory? When was it?
Geocentric theory
Think back to the theory lesson and think about why people may have thought that everything revolved around Earth and there isn't Uranus and Neptune?
1 WALT express significant figures' views on the different models of the universe.
When was it? What do you remember about Nicolaus Copernicus' theory? Heliocentric Ptolemy's Geocentric Theory was revealed in the 2nd century (the 100's) and was accepted up until the 1500's when...
Copernicus revealed his heliocentric theory in 1543.
This shows that Ptolemy's Geocentric theory was believed by many for over 1000 years.
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Hasan Ibn al-Haytham (Latinized as Alhazen)
Born: 965CE Died: 1040CE Born in what is now known as Basra - Iraq.
Arab mathematician, astronomer, and physicist
Alhazen was very successful in researching reflections on objects to our eyes and how humans are able to see (with the brain not eyes). Alhazen‛s study of lenses led to the invention of the microscope and telescope.
He later began to study the math aspect of astronomy and how celestial bodies orbit.
Who do you think Alhazen agreed with and why?
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Alhazen agreed with the Geocentric model. It may be because the 10th and 11th centuries are close to the 2nd in time.
Although Alhazen is credited for many discoveries and theories, he still agreed with Ptolemy's theory about the Earth being the center of the universe and every other celestial body orbiting around it.
Even though he supported this theory, Alhazen still challenged part of Ptolemy's work. He stated that planets orbiting did so at a constant speed and not different speeds.
4 5 WALT express significant figures' views on the different models of the universe. Born: Galileo Galilei 1564 "father of observational astronomy"
Died: 1642
This Italian astronomer was very well known for his many discoveries in our solar system. He managed to discover these all just by observing!
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How do we think Ancient civilisations observed planets and stars?
What instrument is now important to the study of astronomy?
Galileo used an instrument called the telescope whilst it was just newly invented.
He managed to observe beyond our skies and found out A LOT!
Galileo managed to add onto someone's theory? Who's do you think?
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Born: 1564
Died: 1642
If Galileo lived during this period of time, who's theory do you think he would have corroborated?
8 WALT express significant figures' views on the different models of the universe. The Telescope What do we know about the telescope already?
Why is it useful?
In 1608, Hans Lippershey, from Netherlands, invented the telescope which could magnify (enlarge) objects 3x or more.
One year later, Italian physicist and astronomer Galileo became the first person to point a telescope upwards towards the sky.
He was able to identify a ribbon of light arching across the horizon which was later identified as the 'Milky Way Galaxy!'
He was also able to observe Earth's Moon (Luna), planets and other moons. Because of this, he was able to support and debunk theories surrounding the solar system.
The telescope was used long after Galileo to observe our wonders beyond the skies and with technological advances, came more and more knowledge about our solar system and beyond.
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The images may have been fuzzy but Galileo was able to make out the shapes of mountains and craters on the Moon!
400 YEARS AGO!!
Many astronomers and scientist, at the time, believed that Earth's natural satellite was round and smooth, unlike Earth.
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• Galileo discovered the first moons ever known to orbit a planet other than Earth. Jupiter‛s four largest moons, which he discovered: Io, Europa, Ganymede, and Callisto, are together known as the Galilean Satellites in his honor.
Which theory (heliocentric/geocentric) is strengthened by Galileo's discovery of Jupiter's Moons?
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Galileo's discovery of Jupiter's 'Galilean' Moons strengthened the heliocentric theory!
This is because it was now proven that moons were seen orbiting another planet and not Earth which questions the idea that Earth is at the center of the universe.
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• The Italian wonder also discovered the rings of Saturn, although he found their appearance very confusing.
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• Galileo discovered that the Milky Way is made up of Why do you think it is called that? stars.
The Sun (our center star) belongs to a galaxy called the Milky Way. Astronomers estimate there are about 1 billion stars in the Milky Way alone. There may also be billions of other systems in our galaxy!
Our planetary system is the only one officially called “solar system,” but astronomers have discovered more than 2,500 other stars with planets orbiting them in our galaxy. That's just how many we've found so far. There are likely to be many more planetary systems out there waiting to be discovered!
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• Finally, Galileo found that Venus has phases like the moon, ranging from a thin crescent to full. This was the first practical, observational evidence that the sun sits at the center of the solar system.
The orbit of Venus is 224.7 Earth days. The phases of Venus is due to the planet's orbit around the Sun. Because it is beside Earth's orbit, an observer using a telescopic can see a sequence of progressive lighting similar in appearance to the Moon's phases. ... It shows a quarter phase when it is at its maximum elongation from the Sun. Venus will show different phases as it moves around the SUN not earth!!!! Which theory do you think Galileo will agree with and why?
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TASK:
You are going to write a letter in role as Galileo to Alhazen.
This letter will be providing your discoveries and findings and using them as proof that Copernicus' heliocentric theory is correct and that Alhazen is wrong for agreeing with Ptolemy's Geocentric theory!
Which of Galileo's discoveries prove the heliocentric theory right?
Discovery of Jupiter's moons - ORBITING JUPITER!
Observing Venus' orbit and discovering that it goes through phases relative to the Sun - not Earth.
16 WALT express significant figures' views on the different models of the universe. Why are you writing this letter? Introduction
Dear Alhazen and Ptolemy,
I am writing to inform you about all of my recent discoveries thanks to Hans Lippershey's incredible invention. Through my adaptations, I have managed to create the perfect spyglass and I had the amazing idea of simply pointing this sophisticated instrument up to the skies. Through my observations, I have found several strong pieces of evidence that refutes your belief in the Geocentric Theory in turn corroborating the heliocentric theory and I will be talking further about this throughout this letter...
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What have you found out? You can include all of your observations and discoveries in one paragraph to brag but make sure you have the discoveries that link to the heliocentric theory in a separate paragraph!
Jupiter's moons orbiting around Jupiter. There is another planet which has moons orbiting around it. Yet, Jupiter AND Earth cannot BOTH be the center of the universe!
18 WALT express significant figures' views on the different models of the universe. What have you found out? Venus' phases and orbiting the Sun...
Whilst tweaking a few parts of Hans Lippershey's beautiful invention, I managed to create my adapted version and experience observing our world around us. With Copernicus' heliocentric theory only just being released 66 years ago, I was looking with an open mind as well as an open eye! When I turned my telescope to observe further than Earth's moon, I managed to see a very visible celestial body (Venus). After many months of observation, I was able to discover, to my surprise, that Earth's neighbouring planet went through phases - very much like Luna (Earth's moon). This occurred as it traveled along its orbit around the Sun, not Earth. This strengthens the proof that Copernicus' heliocentric model of our universe is correct and Ptolemy's geocentric model cannot be right. Luna must orbit Earth just like Jupiter's moons orbit Jupiter and the planets within our solar system must revolve around the Sun, including Earth!
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How will you conclude your letter? Yes, you can include a little sass...
I understand that my observations of Venus' phases and orbit of the Sun alongside the evidence of Jupiter's moons will lead to the demise of your beloved Ptolemaic model of the universe but these are facts and had to be shared with the world. Hopefully the adoption of Copernicus', correct, heliocentric proposal of the universe in 1543 will now educate the minds of our next generations.
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