2. Who Am I?

3. What do I do?

4. What do I do?

5. What do I do?

6. What do I do?

7. What do I do?

8. What do I do?

9. What do I do?

10. What do I do?
ASTROPHYSICS: “That branch of astronomy which treats of the physical or chemical properties of the celestial bodies. Hence astrophysicist, a student of astronomical physics.”
ASTRONOMY: “The science which treats of the constitution, relative positions, and motions of the heavenly bodies; that is, of all the bodies in the material universe outside of the earth, as well as of the earth itself in its relations to them.”

11. Today we will talk about:
Our Universe
What it is like, how it started, how it evolved to its current state, and how it will end

12. First, let’s look at some of the objects we might find if we explored our Universe

13. Where do we live?

14. Where is the Earth?

15. The Solar System

16. Q: What is a STAR?

18. Our Sun is a star!

19. Stellar Facts A star is a big ball of burning gas
Our Sun is a very average star
When we look out into the night sky, many of the stars we see are very similar to our own sun
In fact some of these stars also have planets, just like our own Solar System

20. What is this?

21. What is it made of?

23. MANY STARS

24. MANY STARS
SOME SUN-LIKE

25. Galactic Facts Stars tend to group together to form galaxies
Galaxies contain hundreds of thousands of stars
At the centre of most galaxies is a massive black hole!
Our sun is part of a galaxy

26. You are here!

28. Our Galaxy from the Earth

29. We live on the Earth
The Earth is a planet in the Solar System, orbiting our star which we call the Sun
The Sun is part of a galaxy
When we look out into the sky at night, all of the stars we see are in our galaxy
But our galaxy is just one of many…..

30. Galaxies: Hubble Space telescope image

31. ‘Zoom out’ - galaxies form filaments and voids

32. It is hard to comprehend the size of the Universe!
We will now all help make a scale model of the solar system to get an idea of the distances we are talking about

33. IN THE BEGINNING…….

34. EVERYTHING!

35. EVERYTHING!

36. STARTS EXPANDING…..
EVERYTHING!
ENERGY INCREASING, BECOMING LIKE A BOMB…….

37. Tick tick tick……

38. BOOM!

39. The Big Bang Not really an ‘explosion’
Universe expanded rapidly as a whole
(Universe is still expanding today as a result of the Big Bang)
Matter was created in the form of tiny particles (protons, neutrons, electrons)
Too hot for normal ‘stuff’ to form (eg atoms, molecules)

41. COSMIC ‘SOUP’

42. COSMIC ‘SOUP’
PROTON
NEUTRON
ELECTRON

43. 300,000 Years Later….. Universe much cooler, atoms start to form…..
Hydrogen, Helium, normal ‘stuff’

45. Universe is now a GAS

46. Universe is now a GAS
HELIUM
HYDROGEN

48. GRAVITY!

49. Gravitational Collapse
We started with a uniform gas
Small regions became more dense
The denser regions had larger gravity and started to pull other particles towards them
The gaseous Universe began to look ‘clumpy’

50. Gravitational Collapse

51. Gravitational Collapse
Regions with more particles (higher density) become gas clouds
Gas clouds become stars and galaxies
Galaxies congregate together in filaments, groups and clusters

52. If we could view the Universe from outside, if would look like this:

53. But we are inside one of these galaxies, so all we see are the
nearby stars. We can see other galaxies if we use a telescope

54. The Gemini Telescope

57. Future? The Universe is still expanding All galaxies are moving apart
The ‘explosion’ of the big bang is still happening!
It may contine expanding forever
Or is may stop expanding, and fall inwards in a big CRUNCH!

58. What have we learnt? The Universe started with a BIG BANG
Gradually the particles were drawn together under GRAVITY to form STARS and GALAXIES
Many stars have planets around them
The fate of the Universe is uncertain…

59. THE END