320 likes | 383 Views
Join our physics class at Serra High School to embark on a journey exploring the mysteries of the universe and mastering the fundamental laws of physics. Learn about planetary motion, discoveries of new planets, and the groundbreaking work of scientists like Tycho Brahe, Johannes Kepler, and Sir Isaac Newton. By delving into topics such as retrograde motion, elliptical orbits, and Newton's laws of motion and gravitation, you will gain a deeper understanding of how the universe operates. Get ready for an engaging and enlightening experience that will change the way you perceive the world around you.
E N D
Welcome !! Serra High School Physics
Homework and Next Class • Write short answers using complete sentences to the following questions: • What kind of work do you think you might want to do when you finish your education? • Physics is an elective class. Why did you choose to take this subject? • DUE FIRST CLASS NEXT WEEK!! • Take 15 – 30 minutes and skim through the textbook. Get a broad picture of the topics covered in the book. • Next time: • Class requirements/rules/regs • Short video on automotive engineering Serra High School Physics
Today we start a journey. • My hope is that it changes the way that you look at the world. • Fifty years from now, in 2060, you will remember this class! Serra High School Physics
1 Corinthians 13:9-12 • 9 For we know in part, and we prophesy in part.10 But when that which is perfect is come, then that which is in part shall be done away.11 When I was a child, I spake as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things.12 For now we see through a glass, darkly, but then face to face: now I know in part; but then shall I know even as also I am known. Serra High School Physics
The Hubble Space Telescope Sky & Telescope, June 2010, p. 21 Serra High School Physics
Stellar Formation Astronomy, September 2010, p. 29 Serra High School Physics
Discovery of New Planets Sky & Telescope, June 2010, p. 25 Serra High School Physics
But we aren’t the first to wonder at the heavens!! Serra High School Physics
University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/retrograde/aristotle.html Serra High School Physics
But there were problems…. • The term “planet” was chosen because it means “wanderer.” • Careful observers noted something bizarre….. Serra High School Physics
Retrograde Motion! Sky & Telescope, July 2010, p. 61 Serra High School Physics
Going around in circles… University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/retrograde/aristotle.html Serra High School Physics
But there were still problems… University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/retrograde/aristotle.html Serra High School Physics
Copernican Model - 1543 University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/retrograde/copernican.html Serra High School Physics
A New Explanationof Retrograde Motion University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/retrograde/copernican.html Serra High School Physics
Tycho Brahe (1546 – 1601) • Made very precise measurements of planetary positions in the night sky. • There were still problems with the Copernican model!!! • “There is a common misconception that the Copernican model did away with the need for epicycles. This is not true … Copernicus was able to rid himself of the long-held notion that the Earth was the center of the Solar system, but he did not question the assumption of uniform circular motion.” University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/retrograde/copernican.html http://csep10.phys.utk.edu/astr161/lect/history/brahe.html Serra High School Physics
Johannes Kepler (1571-1630) • Kepler, a mathematician, was Brahe’s assistant • Doing all calculations by hand, he tried for years to fit the data to circular orbits. • It didn’t work. • He knew the data was accurate so he finally tried elliptical orbits. • After much additional toil - Eureka! University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/history/kepler.html Serra High School Physics
Elliptical Orbit • Slightly flattened circle • a + b = constant • Sun is at one of the foci. University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/history/kepler.html Serra High School Physics
Kepler’s 1st Law University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/history/kepler.html Serra High School Physics
Kepler’s 2nd Law University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/history/kepler.html Serra High School Physics
Kepler’s 3rd Law University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/history/kepler.html Serra High School Physics
Sir Isaac Newton - (1642-1727) Alexander Pope wrote: Nature and Nature's laws lay hid in night; God said, Let Newton be! and all was light University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/history/newton.html Serra High School Physics
Newton’s Second Law of Motion: F = ma or a = F/m • Newton’s Law of Universal Gravitation: University of Tennessee, Knoxville: Astronomy 161 http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html Serra High School Physics
The Clockwork Universe • Given the laws of motion, if you knew the initial position and velocity of every particle, their future paths could be computed (e.g., this is how we know precisely when a spacecraft will arrive at Pluto). • The future is completely predetermined!!?? Serra High School Physics
There were some amazing triumphs… Mario Livio, Is God a Mathematician?, p. 223 Serra High School Physics
and some amazing applications… Mario Livio, Is God a Mathematician?, p. 222 - 223 Serra High School Physics
But there were still problems… • Einstein eventually overthrew Newton’s ideas of gravity – curved space-time?!?!? • Bizarre behavior was discovered at the subatomic level – “particles” jumping from one place to another without crossing the intervening space?!?!? • Try as they might, there were “simple” mechanical problems that physicists could not solve, i.e., three bodies orbiting each other. Serra High School Physics
CHAOS!!!! • In the 20th century, the clockwork universe fell apart! • A video of Steven Strogatz from Cornell http://www.youtube.com/watch?v=anwl6OZ1UuQ&feature=related Serra High School Physics
What does the bug making waves below while hopping across a pond have to do with the expansion of the universe and the greatest mistake that Albert Einstein ever made? Serra High School Physics
Welcome to our world! That is a story for another day… The universe is a strange and fascinating place. If you understand physics, you will literally be able to “see the universe in a grain of sand” and drawing astonishing connections between seemingly unrelated observations. Consider tuning out the distractions of everyday life - look at the heavens and earth closely and THINK! Serra High School Physics
Homework and Next Class • Write short answers using complete sentences to the following questions: • What kind of work do you think you might want to do when you finish your education? • Physics is an elective class. Why did you choose to take this subject? • DUE FIRST CLASS NEXT WEEK!! • Take 15 – 30 minutes and skim through the textbook. Get a broad picture of the topics covered in the book. • Next time: • Class requirements/rules/regs • Short video on automotive engineering Serra High School Physics