Unformatted text preview:

Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Relativityds2 = ( 1 - ) dt2 – (1 + ) dr2 – r2 dθ2 – r2 sin2θ dφ2 “2GMR2GMRTwinkle, twinkle little starHow I wonder where you are“1.75 seconds of arc from where I seem to beForSource UnknownRelativityFrame of Reference - A set of coordinate axes in terms of which position or movement may be specified or with reference to which physical laws may be mathematically stated. Also called reference frame. Relativity – the study of the laws of physics in reference frames which are moving with respect to one another.RelativityRelativity – the study of the laws of physics in reference frames which are moving with respect to one another.Two cases:Case 1 (special case): reference frames move at a constant velocity with respect to each other.Case 2 (general case): reference frames accelerate with respect to each other.Special RelativityIntroduced in 1905 by A. EinsteinSpecial Relativity – the study of the laws of physics in the special case of reference frames moving at a constant velocity with respect to each other.Inertial Reference Frame – a reference frame that moves at a constant velocity.Special RelativityThe Postulates of Special RelativityFirst postulateObservation of physical phenomena by more than one inertial observer must result in agreement between the observers as to the nature of reality. Or, the nature of the universe must not change for an observer if their inertial state changes. Every physical theory should look the same mathematically to every inertial observer. To state that simply, no property of the universe will change if the observer is in motion. The laws of the universe are the same regardless of inertial frame of reference. Second postulate (invariance of c)The speed of light in vacuum, commonly denoted c, is the same to all inertial observers, is the same in all directions, and does not depend on the velocity of the object emitting the light. When combined with the First Postulate, this Second Postulate is equivalent to stating that light does not require any medium (such as "aether") in which to propagate.Special RelativityThe Postulates of Special RelativityAs a result of the second postulate, once the distance to a celestial object is know, one can determine how far in the past the event occurred.Given the speed of light and the distance to the Large Magellanic Cloud, Supernova 1987a actually occurred 160,000 years before the observation, in about 158,000 BC !!Special RelativityThe Postulates of Special RelativityFurthermore, it is understood that no phenomena can travel as a speed greater than 3 x 108 m/secSpecial RelativityThe Postulates of Special RelativityFurthermore, it is understood that no phenomena can travel as a speed greater than 3 x 108 m/secWhat about Neutrinos (September 2011)?Special RelativityThe Postulates of Special RelativityFurthermore, it is understood that no phenomena can travel as a speed greater than 3 x 108 m/secWhat about Neutrinos (September 2011)? Probably not.General RelativityIntroduced in 1916 by A. EinsteinGeneral Relativity – the study of the laws of physics in the general case of reference frames accelerating with respect to each other.Non-Inertial Reference Frame – a reference frame that accelerates.General Relativity – A Thought ExperimentScale reads 170 lb?General Relativity – A Thought Experimentg = 9.8 m/sec2 Scale reads 170 lbScale reads 170 lb??General Relativity – A Thought Experimenta = 9.8 m/sec2 Scale reads 170 lbScale reads 170 lb? ?General Relativity – A Thought Experimentg = 9.8 m/sec2 Scale reads 170 lba = 9.8 m/sec2 Scale reads 170 lbScale reads 170 lb?? ?General Relativity – A Thought Experimentg = 9.8 m/sec2 Scale reads 170 lba = 9.8 m/sec2 Scale reads 170 lbScale reads 170 lb?? ?The Principle of EquivalencyGeneral RelativityPrinciple of Equivalency - Experiments performed in a uniformly accelerating (non-inertial) reference frame with acceleration a are indistinguishable from the same experiments performed in a non-accelerating (inertial) reference frame which is situated in a gravitational field where the acceleration of gravity = g = -a.General RelativityPrinciple of Equivalency 2001 A Space OdysseyGeneral RelativityPrinciple of Equivalency - Experiments performed in a uniformly accelerating (non-inertial) reference frame with acceleration a are indistinguishable from the same experiments performed in a non-accelerating (inertial) reference frame which is situated in a gravitational field where the acceleration of gravity = g = -a. 2001 A Space OdysseyGeneral RelativityPrinciple of EquivalencyCentripetal Generotor at COSIGeneral RelativityPrinciple of Equivalency - Experiments performed in a uniformly accelerating reference frame with acceleration a are indistinguishable from the same experiments performed in a non-accelerating reference frame which is situated in a gravitational field where the acceleration of gravity = g = -a. Centripetal Generotor at COSIWhen riding the Centripetal Generotor, you spin slowly at first, while increasing velocity. The force eventually pins you to the wall as the floor drops away. At about 3 g’s or 33 rpm's, the centripetal force is strong enough to make the static friction greater than the force of gravity, so when the floor drops away, you stick to the wall. When the rotor’s speed decreases, so does the centripetal force and the static friction, and you slide to the floor.General RelativityHow is the Generotor G-force calculated? The force of Gravity (G) on Earth is used as a baseline for measuring these forces of acceleration. The force of gravity when you sit, stand, or lie down is considered 1 G. In normal activity, we rarely experience anything other than 1 G. As you exert more G's on the body, your weight increases correspondingly. Your 10-pound head will weigh 90 pounds when you pull 9 G's!If you continue to pull high G's, the G force will push the blood in your body towards your feet and resist your heart's attempts to pump it back up to your brain. You will begin to get tunnel vision, then things will lose color and turn white, and finally everything will go black. You've just experienced the onset of Gravity Induced Loss of Consciousness (GLOC). Riding the Generotor will not


View Full Document

Dayton PHY 250 - Relativity

Documents in this Course
Diagrams

Diagrams

24 pages

The Sun

The Sun

11 pages

Load more
Download Relativity
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Relativity and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Relativity 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?