PHYS 190 Lecture Notes - Lecture 9: Neutrino, Electromagnetism, Fundamental Interaction
27 Nov 2020
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First step: held together by the strong" nuclear force. Net reaction: 2 positrons comes out, encounters electron which will turn into more energy, not included in equation, 2 neutrinos v, 4. Inco creighton mine, sudbury, ontario: art mcdonald, queen"s university. Properties of stars: remarkably, most stars exhibit a tight correlation in their properties, distance, luminosity, temperature, radius, mass, lifetime. Star a had mag 1 and star b has mag 6: a is 100x brighter than b, defn" implies difference of 1 mag is factor of about 2. 5 in brightness. 2. 5 x 2. 5 x 2. 5 x 2. 5 x 2. 5 = 100: *do not use in this course* Temperature from colour: simplest estimates use two filters: blue and green ( visual", see slide pg. 5. Colour is temperature only for blackbodies red=hot: blue=not, reflects blue light, not a blackbody. Apparent brightness: luminosity = energy emitted per second, ex. 60-watt bulb: apparent brightness also depends on distance.
