1. Topic 2 Space Exploration
Stronger Eyes and Better Numbers
Topic 2
Space Exploration

2. Telescopes Throughout ancient times, the mapping of stars improved
However, the Telescope really helped astronomers to see more and understand more

3. Hubble Space Telescope - Chapter 1

4. Telescopes Telescope:
A device used to magnify objects at great distances
Objective Lens:
The large lens at the front of a telescope.
Ocular Lens / Eyepiece:
The lens through which you view a magnified object using a telescope

5. Telescopes

6. Telescopes
Hans Lippershey (a Dutch spectacle maker) invented the telescope in 1608
Later in that century, Galileo Galilei (an Italian astronomer) improved the telescope and used it to look at celestial objects

7. Telescopes
Note: Galileo was the first to observe the moon’s blemishes, sun spots, Jupiter’s moons, and realized that stars were much further away from us than the planets.

8. Galileo’s Approach to Inquiry
Galileo’s observations supported Copernicus’s Sun- Centred model
However, his observations did not support Ptolemy’s Earth-Centred model

9. Galileo’s Approach to Inquiry
Because he was able to see Jupiter’s moons orbiting Jupiter and not Earth, he realized that not all celestial objects orbit Earth and thus disproved Ptolemy’s Earth-Centred model.

10. Galileo Sun-Centered System

11. Resolving Power
In order to build a more powerful telescope you need to increase its resolving power
Resolving Power:
Determines the fineness of detail a telescope can produce of an object in view

12. Resolving Power
Resolving power depends on the diameter of the objective lens
Smaller Diameter = high magnification
Large Diameter = finer detail and high resolving power

13. Refractors and Reflectors
Many different telescopes have been invented since Galileo’s time including the Refracting Telescope and the Reflecting Telescope

14. Refractors and Reflectors
Refracting Telescope:
A Telescope that has a lens for its objective

15. Refractors and Reflectors
Reflecting Telescope
A Telescope that has a mirror for its objective

16. Refractors and Reflectors
Sir Isaac Newton designed the first Reflecting telescopes to overcome the problem that Refracting telescopes had

17. Refractors and Reflectors
Refracting Telescope
Reflecting Telescope
Advantage:
Give better images
Disadvantage:
Could not focus different colours in the same place
Can focus different colours in the same place
Can be made much larger
Give poor quality images

18. Refractors and Reflectors
New telescopes have been created that incorporate both types of telescopes into one called Combination or Catadioptric Telescopes

19. Copernicus’s Sun-Centred Revolution Continues
Although Galileo’s telescopic observation helped to confirm Copernicus’s Sun- Centred model of the Universe, Copernicus’s model still needed work

20. Copernicus’s Sun-Centred Revolution Continues
Johannes Kepler:
In 1609, Johannes Kepler, a German mathematician, found that the planets’ motions would be more accurate if planetary orbits were elliptical rather than circular

21. Copernicus’s Sun-Centred Revolution Continues
Johannes Kepler:
Ellipse:
A figure that looks like a squashed circle
Planets in the solar system move in elliptical orbits around the Sun

22. Copernicus’s Sun-Centred Revolution Continues
Johannes Kepler:
Kepler determined this through mathematics and observation
Kepler was given the task of figuring out the orbit Mars using mathematics

23. Copernicus’s Sun-Centred Revolution Continues
Johannes Kepler:
Kepler used the star charts of Tycho Brahe (a famous astronomer) and found that the only way to explain Tycho Brahe’s observations of Mars’ orbit around the sun was that it had to be elliptical in shape
This work took him two years

24. Copernicus’s Sun-Centred Revolution Continues
Johannes Kepler:
Not only did Keplers work determine that orbits are elliptical and not circular, but he also determined the shape and scale of the entire known solar system
Brahe and Kepler

25. Universal Gravitation
Aristotle:
Used philosophical and geometric models of the universe
Kepler:
Used mathematical models of the Universe based on more accurate observations of the celestial bodies

26. Universal Gravitation
Isaac Newton:
Eighty years after Kepler described the elliptical shape of the planets’ orbits, Isaac Newton stated the law of Universal Gravitation

27. Universal Gravitation
Isaac Newton:
Universal Gravitation:
Newton’s law states that all objects attract all other objects, and provides an explanation for the planets’ elliptical orbits

28. Universal Gravitation
Isaac Newton:
Newton stated that there is a gravitational force between all objects that pulls them together (like a 3- Dimensional dent in space)

29. Universal Gravitation
Isaac Newton:
When no force acts on an object it will move in a straight line at a constant speed

30. Universal Gravitation
Isaac Newton:
The planets are always in motion, however the force of gravity from the Sun balances their tendency to move in a straight line and results in the planetary orbits.

31. From Newton to Einstein - The Elegant Universe