Chapters 15,16 Special Relativity

Space Time Space and Time in Universe, not other way around Space and Time are connected, we move through them together Mostly at rest, only through time

Motion is Relative Walking on a bus, 1km/h to bus, 101 km/h to ground

Speed of Light Speed of light a constant, time, space are not Chicago to LA how long does it take? Wagon train, walk, bike, car, train, jet, rocket, light Moon, Sun

Constant Speed of Light? 1st found in 1887 by Michelson/Morley won Nobel prize Demonstrated Experimentally many times since

Einstein starting point 1st Postulate - Laws of nature same in all constantly moving frames as at rest 2nd Postulate - Speed of light is constant

Results of constant speed of light Chalk demo Light Clock Space/time = c = SPACE/TIME Always OTHER person seems to be moving slower See graph pg 222

Twin Trip Time is different measured on earth and on spaceship! Start page 224 t = t0/√(1-v2/c2)

Length Contraction Objects appear shorter when traveling close to the speed of light Pic pg 233 L = L0 √(1-v2/c2)

Momentum Give impulse = more momentum still holds in Einstein's world Velocity has limit at c. ρ = mv/√(1-v2/c2) Mass must be increasing!!

Momentum If adding energy (by impulse) increases mass, mass ~ energy? E = mc2 ‘Mass is congealed energy’ E = mc2 applies in all energy equations

Newton vs. Einstein Correspondence Principle Einstein’s equations simplify back to Newton’s

General Relativity Gravity is caused by curved spacetime Spacetime gets curved by things with mass Demo