100 likes | 207 Views
The Size of Space. Relative Size. Which ratio is bigger? A. The NIU campus compared to me. B. The earth compared to DeKalb. C. Our galaxy compared to the solar system. D. The universe compared to our galaxy. Length. The oldest standards of length were based on the human body.
E N D
Relative Size Which ratio is bigger? • A. The NIU campus compared to me. • B. The earth compared to DeKalb. • C. Our galaxy compared to the solar system. • D. The universe compared to our galaxy.
Length • The oldest standards of length were based on the human body. • The metric system defined the meter in terms of the Earth: 1/10,000,000 from the pole to the equator. • The meter is now defined in terms of the second and speed of light. • The SI unit of length is the meter (m)
Me: 5’9” = 1.75 m = 2 x 100 m Lecture Hall: 14 m = 1 x 101 m Faraday West: 80 m = 0.8 x 102 m NIU Campus: 2400 m = 2 x 103 m People-sized Spaces New Zealand Digital Library
NIU campus: 2400 m = 2 km = 2 x 103 m DeKalb county: 29,000 m = 30 km = 3 x 104 m Illinois: 338 km = 3 x 105 m United States: 5000 km = 5 x 106 m Map-sized Spaces mapquest
Astronomical Unit • Earth’s diameter: 13,000 km = 1 x 107 m • Earth to the Moon: 384,000 km = 4 x 108 m • Earth to the Sun: 150,000,000 km = 1.5 x 1011 m = 1 AU • The astronomical unit (AU) is the average distance from the earth to the sun.
Planetary-sized Spaces • Sun to the Earth: • 1 AU = 1.5 x 1011 m • Sun to Saturn: • 9.58 AU = 1.4 x 1012 m • Solar System (heliopause): • 121 AU = 1.8 x 1013 m
How long does it take light to go from the Sun to the Earth? The speed of light is 3.0 x 108 m/s How far does light travel in one year? (1.5 x 1011 m) / (3.0 x 108 m/s) / (60 s/min) = 8.3 minutes (3.0 x 108 m/s) x (3.1 x 107 s) = 9.46 x 1015 m = 63,240 AU This equals one light year (ly) Light Year
Space-sized Spaces • Sun to nearest star: • 300,000 AU = 4.3 ly = 4 x 1016 m • Diameter of Milky Way: • 110 kly = 1 x 1021 m • Diameter of Local Group • 10 Mly = 1 x 1023 m • Diameter of Virgo Supercluster • 110 Mly = 1 x 1024 m • Extent of the observable universe: • 36 Gly = 3 x 1026 m
How big? A. NIU campus compared to me. (103) B. The earth compared to NIU. (104) C. Our galaxy compared to the solar system. (108) D. Universe compared to our galaxy. (105)