it’s all relativity. march, 1905: twenty six year old albert einstein demonstrates the particle...
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It’s all Relativity
March, 1905: Twenty six year old Albert Einstein demonstrates the particle nature of light by explaining the photoelectric effect.
He won the Nobel Prize for that in 1921.
What have you done with your
life so far?
ALICE detector – A Large Ion Collider Experiment
Atlas detector, LHCPhoto and detector courtesy of CERN
The Higgs boson, dark matter, and a few extra dimensions
Einstein’s First Postulate:The laws of physics are the same
in every inertial frame of reference.
Einstein’s Second Postulate:The speed of light in a vacuum is the
same in all inertial frames of reference, and is independent of the
source.
June, 1905, Einstein proposes the special theory
of relativity.
Measurements of distance and time are not absolute, but depend on the
motion of the observer.
Isaac Newton’s laws were only part of
the story.
Slide 27-4
Slide 27-5
Two Standard Reference Frames
Slide 27-14
Inertial Reference Frames
Slide 27-15
The Galilean Velocity Transformations
Slide 27-16
The Constancy of the Speed of Light
Slide 27-19
The Relativity of Simultaneity
Slide 27-26
The Events in Ryan’s Frame
Slide 27-27
The Events in Peggy’s Frame (??)
Slide 27-28
The Actual Sequence of Events in Peggy’s Frame
Slide 27-29
Figure 37.5b
Figure 37.5c
Figure 37.5d
Figure 37.6a
Figure 37.6b
Figure 37.10
Figure 37.12
Simultaneity is ToastEverything is Relative
The different times of flight aren’t just an artifact
They mean that time is not a fixed, rigid, linear system
Time dilation is the first result
Solve the eqns for t0 in terms of t, eliminating d and you find that time depends on the frame of the observer
2 d/c ≠ 2 l/c
The Lorentz Transformations
Gamma, the core equation of relativity. This relation crops up so many times that it has its own name.
Time and space both vary with gamma.
They are no longer linear or independent, but are interwoven and termed “spacetime.”
Figure 37.8
Time Dilation
• Time in a reference frame that is moving in relation to the observer passes more slowly.
• The difference is small at low velocities, and become infinite as the speed of light is approached.
• Newton’s linear model of space and time collapses at what are called “relativistic velocities.”
This is “special relativity” relating to motion. General relativity is more general
Time Dilation and Proper Time
Slide 27-32
The Twin Paradox
Slide 27-33
Length Contraction
Length of object in frame in which it’s at rest
Length of object in a frame in which it’s moving at β = v/c
Slide 27-34
Lorentz Velocity Transformations
Slide 27-35
Relativistic Momentum
where
Slide 27-36
Relativistic Energy
The total energy is made up of two contributions:
Slide 27-37
Conservation of Energy in Relativity
Slide 27-38
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