1. Prof Martin Hendry University of Glasgow

4. A long time ago, in a galaxy far, far away…

6. The nature of the nebulae?… Early 20 th Century Gas clouds within the Milky Way, or Island Universes?….

11. Galaxy Laboratory

14. Hubble’s Law

17. “Space tells matter how to move, and matter tells space how to curve” Gravity in Einstein’s Universe

22. Will the Universe expand forever?... It depends how much matter there is

24. Weighing the Solar System Johannes Kepler Isaac Newton

25. Vera Rubin 1970s: studies the rotation of spiral galaxies. Weighing galaxies Galaxies were spinning faster than they should be!

28. What we see What we think is really there…. 10 times as much as the luminous matter in the visible galaxy

33. Will the Universe expand forever? Answer depends on the density of matter in the Universe. Density high enough to cause re- collapse, leading to ‘Big Crunch’ Density too low; Universe expands forever ‘Critical’ density

34. So, is the expansion slowing down?...

35. Answer depends on the shape of the Universe

36. Closed

37. Answer depends on the shape of the Universe Closed Open

38. Answer depends on the shape of the Universe Closed Open Flat

40. redshift ‘Speeding up’ model ‘Slowing down’ model Hubble’s law for nearby supernovae Hubble diagram of distant supernovae measure of distance

44. So what exactly is this dark energy?...

46. redshift Latest results: still speeding up... measure of distance

48. Early Universe too hot for neutral atoms to exist Free electrons scatter light (as in a fog)

49. Early Universe too hot for neutral atoms to exist Free electrons scatter light (as in a fog) After ~380,000 years, Universe cool enough for neutral hydrogen to form: the fog clears!

50. Background radiation predicted in 1950s and 1960s by Gamov, Dicke, Peebles. Discovered in 1965 by Penzias and Wilson Arno Penzias and Robert Wilson Robert Dicke Jim Peebles

52. COBE map of temperature across the sky

53. CMBR ‘ripples’ are the seeds of today’s galaxies Galaxy formation is highly sensitive to the pattern of CMBR temperature

55. WMAP map of temperature across the sky

57. Adapted from Bassett & Nichol (2006)

58. Coming attractions...

59. Multi-wavelength (messenger) Ground- and space-based Multiple cosmological probes: Many opportunities for better constraining dark matter and dark energy models  Supernovae  Gamma-ray bursts  GW ‘Sirens’  Baryon Acoustic Oscillations  Galaxy Cluster Statistics  Weak Gravitational Lensing