1 / 30

Chapter Twenty-Six

Chapter Twenty-Six . Questions of the Day. What is the speed of light? How did they measure the speed? What is the theory of special relativity? How does it relate to the distances of galaxies? What is the theory of general relativity? How does it relate to gravitation?

egan
Download Presentation

Chapter Twenty-Six

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter Twenty-Six

  2. Questions of the Day • What is the speed of light? How did they measure the speed? • What is the theory of special relativity? How does it relate to the distances of galaxies? • What is the theory of general relativity? How does it relate to gravitation? • How was the Universe created? What is the current state of the Universe?

  3. What is the speed of light? • 3 X 108 m/s • The speed of a wavicle of light. • Nothing in our matter-dominated universe can go faster than wavicles of light.

  4. How did they measure the speed of light? • Galileo Galilei • Two mirrors method • Michelson - Morely Interferometer • Fringe method • Modern method • Two-lengths of fiber-optic • Laser Moon Method • Laser bounces of a reflector

  5. Albert Einstein • 1879 – 1955 A.D. • Born in Germany of a business man and wife • Enter Zurich Polytechnic • Worked as a patent clerk after college • Had two wives, Mileva and Elsa. • Worked in Germany until going to US at Princeton. http://home.utm.net/pan/einstein.jpg

  6. Special Relativity • Two basic postulates • The speed of light is the same for all observers, no matter what their relative speed. • The laws of physics are the same in any inertial frame of reference. This means that the laws of physics observed by a hypothetical observer traveling with a relativistic particle must be the same as those observed whose is stationary in the laboratory

  7. Special Relativity (cont.) • First result: Time dilates in each frame. • =1/1-(v2/c2) • t=t’ • Thought Experiment: The Twin Paradox • Second result: Energy is conserved in any frame of reference. • E=m2c4 + p2c2 E=mc2 • Thought Experiment: Billiard Balls

  8. The Twin Paradox NOVA Online/Einstein Revealed/Time Traveler/Game/

  9. Spectra shift

  10. General Relativity • Newton’s Theory of Gravity • F=GM1M2/d2 • Problem: The orbit of Mercury processed around the sun. • Solution: Einstein imagined that the orbit of Mercury was interacting the highly warped gravitational field.

  11. General Relativity (cont.) • Equivalence Principle • If all accelerated systems are equivalent (from special relativity), the Euclidean geometry cannot hold in all of them. • Gab = 8  Tab • Where G is the gravitational constant described by Newton,  is density of the universe, and T is the stress-energy tensor of the universe.

  12. Euclidean Geometry

  13. NonEuclidean Geometry

  14. Curved Spacetime Orbits in Strongly Curved Spacetime

  15. Curved Spacetime

  16. Dust Around a Black Hole http://www.damtp.cam.ac.uk/user/gr/public/images/HSTngc4261.gif

  17. The Center of the Milky Way APOD: 2000 December 20 - Sgr A: Fast Stars Near the Galactic Center.

  18. Kepler versus Einstein

  19. Lens http://www.stsci.edu

  20. Hubble Motion

  21. Hubble and the Gravitational Constant

  22. The Big Bang • Current model of the creation of the Universe • Steps: • Graphical timeline of the Big Bang - Wikipedia, the free encyclopedia

  23. Matter Recombination

  24. Elemental Creations

  25. Elemental Creations

  26. Recombinations

  27. Cosmic Microwave Background

  28. Wilkinson Microwave Background

  29. Current State of Universe • Composition • 70% Dark Energy (?) • 24% Dark Matter (Neutrinos, Planets) • 4% Light Matter (Stars, Galaxies) • Hubble Constant = 72 km/s/Mpc • k = 1 or accelerating in its expansion

More Related