Big Bang Black Holes No Math ASTR PHYS 109 Dr David Toback Lectures 8 9 Big Bang Black Holes No Math Physics We Need Topic 2 Gravity 1 Prep For Today is now due L8 Reading BBBHNM Unit 2 Pre Lecture Reading Questions Unit 1 Still working on re grades Haven t posted grades in eCampus so there is no Revision to start yet If you think you were misgraded send an email to 109help Unit 2 Stage 2 Was due before class Let us know if you were misgraded End of Chapter Quizzes Chapter 5 parts a b Paper 1 Not yet assigned Honor s Paper Stage 0 Due Sept 26th Big Bang Black Physics We Need 2 Holes No Math Topic 2 Gravity Prep For Today is now due L9 Reading BBBHNM Unit 2 already due Pre Lecture Reading Questions PLRQ Unit 2 Revision if desired Stage 2 Was due today before class End of Chapter Quizzes Chapter 5 parts a b Bang Black BigPapers Physics We Need Holes No Math Topic 2 Gravity 3 Heads Up Paper 1 What is the In order to understand evidence for the evidence Dark we next talk Matter about gravity This will be and Dark the topic of Matter Paper 1 Will be due 1 Big Bang Black Holes No Math week after Physics We Need finish Topic 2 we Gravity 4 Next few slides are on course organization grades etc http people physics tamu edu toback 109 CourseOrganization pdf And http people physics tamu edu toback 109 ClassSchedule pdf Big Bang Black Holes No Math Papers Physics We Need Topic 2 Gravity 5 Outline for Unit 2 Physics We Need Topics 1 Light and Doppler Shifts Done 2 Gravity General Relativity and Dark Matter Today 3 Atomic Physics and Quantum Mechanics After that 4 Nuclear Physics and Chemistry 5 Temperature and Thermal Equilibrium Big Bang Black Holes No Math Physics We Need Topic 2 Gravity 6 Why Gravity Next By looking at photons light we can learn about things here on Earth as well as about inner outer space What else do we need to describe understand the Universe Quantum Mechanics and Gravity To understand the answer to Big Bang Black Physics We Need 7 Holes No Math Topic 2 we Gravity these questions need to The Two Great Theories Chapter 6 General Relativity Gravity Predictions about the very large from sizes of a few meters to the size of the universe 1024 miles across Chapter 7 Quantum Mechanics Predictions about the very small atoms particles 10 10 m Big Bang Black Holes No Math Physics We Need Topic 2 Gravity 8 Overview of Gravity for the Course 1 What s so important about Gravity 2 Newton s Theory of Gravity 3 Einstein s more correct version Curved SpaceTime Big Bang Black and Physics We Need Holes No Math evidence for Topic 2 Gravity 9 Gravity Why do we care Gravity The great attraction in the Universe Gravity is the theory that predicts the attraction and the motion of BIG things over large distances Planets Suns Galaxies How Galaxies form etc Big Bang Black Holes No Math Physics We Need Topic 2 Gravity 10 Newton and Gravity 1 Everything moves in a straight line unless acted upon by a force 2 Gravity is a force Every object in the universe attracts every other object in the universe The further the distance between the objects the smaller the attraction Physics 201 The bigger the mass or 218 the bigger the Big Bang Black Physics We Need 11 attraction Holes No Math Topic 2 Gravity Large Number of Scales Kinda amazing Gravity covers the attraction between An apple near the Earth The Earth and the Moon The Earth and the Sun The Sun and our galaxy Our galaxy and the universe Every particle in the universe and an apple The Earth and you Bevo Big Bang and BlackReveille Physics We Need Holes No Math Topic 2 Gravity 12 Gravity continued The force of Gravity makes the Moon fall towards the Earth Call this an orbit Without gravity the Does a great Moon would fly off job of into space and Big Bang Black Physics We Need 13 ignore the Earth Holes No Math explaining how Topic 2 Gravity What s next Tell you the different and surprising way that Einstein describes space time and gravity Then tell why his description of why the Earth goes around the Sun is better than Newton s Big Bang Black Holes No Math Physics We Need Topic 2 Gravity 14 Einstein in the 1910 s In the early 1910 s Einstein was thinking about some recent experimental results that didn t make any sense to him using Newton s theories Decided we need new ways of thinking about space time and Gravity Einstein says that Newton s Laws aren t 2nd year Grad really quite right School Course Einstein s theory is Big Bang Black Physics We Need 15 known as the General Holes No Math Topic 2 Gravity Observational Fact Light ALWAYS moves at the speed of light to all observers So what Big Bang Black Holes No Math Physics We Need Topic 2 Gravity 16 What happens if I m driving a car moving at half the speed of light and I turn the headlights on Big Bang Black Holes No Math Physics We Need Topic 2 Gravity 17 Two observers get different answers The light is one foot ahead of that car The light is two feet ahead of me Big Bang Black Holes No Math Physics We Need Topic 2 Gravity 18 Einstein s Answer Big Bang Black Holes No Math Einstein says both observers are correct Space and Time are more related Physics We Need 19 than we Topic 2 Gravity Start with Space Time Can t think of Space and Time as separate Space measured with a ruler Time measured with a clock Single combined entity which we call four dimensional space time Big Bang Black four Physics We Need 20 If the dimensions are Holes No Math Topic 2 Gravity Other Weirdness Space and time are not only more related than we thought Space can Curve Need to talk about what we mean by Space Time BigCurved Bang Black Physics We Need 21 Holes No Math Topic 2 Gravity We ll start by using the strange new words of General Relativity in an example about why we care and THEN explain them a bit more Big Bang Black Holes No Math Physics We Need Topic 2 Gravity 22 Example Newton vs Einstein Newton The Earth moves around the Sun because of the force of gravity is pulling it Einstein There is no force of Gravity the Earth moves in a straight line around the Sun in the curved space time created thedifferent Sun This is aby VERY way of thinking about things Big Bang Black Holes No Math Physics We Need Topic 2 Gravity 23 Curved Space An analogy is to think of curved space time as looking like one of those gravity wells 1 floor of the you ve seen Big Bang Black Physics We NeedMitchell Physics24 downstairs …