Hie-Joon Kim Professor Emeritus Seoul National University B.S. Chemistry, Seoul National University, Korea, 1970 Ph.D. Chemistry, University of Chicago, USA, 1977 Experience Professor, Department of Chemistry Seoul National University (1997-2012) Chair Professor, Gw angju Institute of Science and Technology (2013-Present) SNU Teaching Aw ard (2007) Representative Publications Philosophical Questions Scientific Answ ers (Thinking Power Books, 2012) Chemistry of Life, Chemistry for Life (Free Academy, 2009)
Chapter 4 Expansion of the Universe
INTRODUCTION Proc. Nat. Acad. Sci. (1929) A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae Edwin Hubble http://2.bp.blo gspot.com/_xy K0EVHYM 8Q/S 9i38IyfS3I/AAA AAAAAAUQ/U KOIvCSlqK8/s3 20/Andromeda +Galaxy+1.jpg http://astrono mylinks.wikisp aces.com/file/ view/pic_2.jp g/327424970 /pic_2.jpg
4-1 Leavitt' s Stars Determinations of the motion of the sun with respect to the extra-galactic observer stationary galaxy nebulae have involved a K term of several hundred kilometers which observer receding: redshift galaxy appears to be variable. observer approaching: blueshift galaxy
4-1 Leavitt' s St ars Distances of extra-galactic nebulae depend ultimately upon the application of absolute-luminosity criteria to involved stars whose types can be recognized. These include Cepheid variables, novae, and blue stars involved in emission nebulosity.
4-1 Leavitt' s Stars Variable Star Henrietta Leavitt (1868-1921) http://3.bp.blogspo t.com/- PM M 3TLx4gzc/T6I 3DaqOxaI/AAAAA AAAKT8/nEttL7lUs EU/s400/Leavitt_he nrietta_b1.jpg brightness time the brighter variables have the longer periods (1908)
4-1 Leavitt' s St ars Cepheid variable in Andromeda Galaxy Edwin Hubble at Mt. Wilson Observatory http://3.bp.blogspot.co m/- zucxiuqxdu8/th1qfyn ykki/aaaaaaaacc8/h 1A4sC_fUDc/s400/hub ble_mtwilson.jpg http://www.aip.org/hist ory/cosmology/ideas/im ages-ideas/ M essier- 31.jpg
4-2 Hubble's Law Radial velocities of 46 extra-galactic nebulae are now available, but individual distances are estimated for only 24. Magellanic Cloud http://farm9.staticflickr.com/8374/8579532405_ 13d272476d_z.jpg The first seven distances are the most reliable, depending upon extensive investigations of many stars involved.
4-2 Hubble's Law For such scanty material, so poorly distributed, the results are fairly definite. EDWIN HUBBLB, A RELATION BETWEEN DISTANCE AND RADIAL VELOCITY AM ONG EXTRA-GALACTIC NEBULAE, January 17, 1929.
4-2 Hubble's Law http://upload.wikimedia. org/wikipedia/commons /thumb/a/a7/v.m._sliph er.gif/220px- V.M._Slipher.gif Vesto Slipher The results establish a roughly linear relation between velocities and distances among nebulae for which velocities have been previously published, and the relation appears to dominate the distribution of velocities. The Radial Velocity of the Andromeda Nebula (1913)
4-3 Milton Humason In order to investigate the matter on a much larger scale, Mr. Humason at Mount Wilson has initiated a program of determining velocities of the most distant nebulae that can be observed with confidence. Hubble & Humason(1931) Milton Humason http://1.bp.blogspot.co m/- RhGWCK_jwRU/UGqYN Se6JUI/AAAAAAAAAFU /Kc5j8Y8azTo/s1600/Mil ton+humason.jpeg Velocity (km/sec) 20,000 15,000 10,000 5,000 1929 Data 10 20 30 Distance (Mpc)
4-3 Milton Humason
4-4 Expansion of the Universe New data to be expected in the near future may modify the significance of the present investigation or, if confirmatory, will lead to a solution having many times the weight. For this reason it is thought premature to discuss in detail the obvious consequences of the present results.
4-4 Expansion of the Universe http://3.bp.blogspot.com/- CZ4mfKybFy4/UGqnWcTiIII/AAAAAAAAAIU/9sepBKIkvq8/s640/Visit a+de+einstein+en+1931+al+monte+wilson.jpeg https://singularidad.files.word press.com/2007/09/eddington _2.jpeg Arthur Eddington The Expanding Universe (1933)
Review The Big Bang cosmology, If we use the tripod analogy, Stands on three pillars. The first is the expanding universe. The second is the cosmic background radiation. Together they form a strong foundation. Then we have cosmic elemental abundance Giving the model a firm stance.
Big Bang and the Origin of Chemical Elements THANK YOU