Unit 5: Galileo Galilei Flashcards
(47 cards)
Who was the first astronomer to use a telescope to study the universe?
Galileo Galilei
How did Galileo’s use of the telescope impact the heliocentric debate?
He added new observational evidence that supported heliocentrism.
When and where was Galileo born?
Pisa, Italy in 1564
Did Galileo invent the telescope?
No, but he was the first to use it for astronomical observation.
What key figures had already published major astronomical works before Galileo?
Copernicus, Brahe, and Kepler
What scientific principle allows telescopes to work?
Refraction – the bending of light as it passes from one medium to another.
What does ‘telescope’ mean?
‘Tele’ means far and ‘scopus’ means to see – ‘far-seeing’.
What is the main difference between a microscope and a telescope?
Microscopes magnify nearby objects; telescopes magnify distant ones.
What did Galileo use to magnify distant objects in his telescope?
A primary lens and a concave eyepiece.
What design flaw existed in Galileo’s telescope?
Limited field of view—only the center was fully visible.
How did Kepler improve the telescope design?
He used a convex eyepiece placed beyond the convergence point of light rays.
What benefits did Kepler’s telescope design have?
Wider field of view and brighter images.
What is the largest refracting telescope ever built?
The 1-meter Yerkes refracting telescope in Wisconsin.
Why can’t refracting telescopes be much larger than 1 meter?
Lenses larger than 1 meter warp under their own weight, distorting images.
What kind of telescopes do modern large observatories use?
Reflecting telescopes, which use mirrors instead of lenses.
What is the main advantage of reflecting telescopes over refracting ones?
They can be made larger and more compact without lens distortion.
What was the name of the observatory with a 1-meter reflecting telescope mentioned in the lecture?
The Allan I. Carswell Observatory at York University.
What was Galileo’s belief before using a telescope?
He already believed in a heliocentric planetary system.
How do we know Galileo believed in heliocentrism before using a telescope?
He admitted it in letters exchanged with Kepler.
Why did Galileo hesitate to share his heliocentric views?
He feared public derision and the fate of Copernicus.
What historical event might have influenced Galileo’s silence?
Giordano Bruno was burned at the stake for heresy.
What was the name of Galileo’s first book of telescope observations?
The Starry Messenger (1610).
What did Galileo discover about the Moon?
It had craters, mountains, and dark patches, contradicting Aristotle’s claim of perfection.
What are the large dark patches on the Moon called?
Maria, which are dried lava plains.
