1. Time-scale and Distance (시간 척도와 거리)

2. Earth radius km
Moon-Earth distance 3.8105 km
Sun-Earth distance 1.5108 km
1 AU (astronomical unit)

3. Parallax시차 (視差)
Parallax is the effect whereby the direction of an object appears to differ when viewed from different positions.
Parallax = angle subtended by 1 A.U., the distance from Earth to the Sun. (1/2 of the diameter of Earth's orbit).
As distance increases the parallax angle decreases. Ultimately limited by the smallest angles measurable.
The distance at which 1 A.U. subtends 1" (one arc second) is called 1 parsec (pc). (parallax arc second). dpc = 1/p(”)
1 pc = 3.26 Light-years. Distance to nearest star,  Centauri
p = 0.762" ---> d = 1.31 pc = 4.27 light-years
Infinite === 무한
Isosceles triangle

5. 1 parsec = 3.26 light year = 3.09×1013 km
1” = 1 arcsecond = 1/3600 degree
1AU
1 parsec = 3.26 light year = 3.09×1013 km

6. Parallax시차 (視差)
Parallax is the effect whereby the direction of an object appears to differ when viewed from different positions.
Parallax = angle subtended by 1 A.U., the distance from Earth to the Sun. (1/2 of the diameter of Earth's orbit).
As distance increases the parallax angle decreases. Ultimately limited by the smallest angles measurable.
The distance at which 1 A.U. subtends 1" (one arc second) is called 1 parsec (pc). (parallax arc second). dpc = 1/p(”)
1 pc = 3.26 Light-years. Distance to nearest star,  Centauri
p = 0.762" ---> d = 1.31 pc = 4.27 light-years
Infinite === 무한
Isosceles triangle

9. Virgo cluster (처녀자리 은하단, 室女座星系團)

11. Chronology of the Universe
우주의 연표 (연대기)
13.7 Gyr
Big bang; formation of the elements H and He
13.4 Gyr
First stars and galaxies; first supernova explosions produce the heavy elements (C,N,O,Si,Fe,…)
12 Gyr
Formation of the milky way
4.567 Gyr
Formation of the solar system; at this point in time the interstellar medium has been enriched with 1% heavy elements
Formation of the earth and the moon
4.5 Gyr
Layer structure of the earth
4.45 Gyr
Solid earth crust
4.4 Gyr
Early ocean
4.2 Gyr
Plate tectonics
4 Gyr
Earth’s magnetic field
Origin of life
>3.5 Gyr
Formation of oxygen-rich atmosphere; formation of ozone
2.3 Gyr
0 Gyr
Today

12. 우주의 달력 : 우주의 탄생에서 현재까지를 1년으로 두었다
Cosmic Calendar
Cosmic Calendar: Scale 12 Billion year history of universe into one year.
1 month = 1 Billion years.
우주의 달력 : 우주의 탄생에서 현재까지를 1년으로 두었다
Jan 1: The Big Bang
Feb. : The Milky Way forms
August 13: The Earth forms
December 13: Invertebrate (무척추) Life Evolves
December 25: Rise of dinosaurs
December 30: Dinosaurs extinct
December 31: 9:00 pm Earliest human ancestors
December 31: 11:59:47 pm Pyramids were built
December 31: 11:59:58.4 pm King Sejong was born