Basic Requirements of Projects PHYS 342 Modern Physics ...

Basic Requirements of Projects

PHYS 342 Modern Physics

Project Discussion I

Grading Method

Quality of

Slides

Quality of

Physics

Presentation

Skills

Presentation

(Points given by your classmates)

10

20

20

Quality of

Writing

Quality of

Physics

Broadness of

Contents

Report

(Points given by me)

10

20

10

Attendance of Presentation

(decided by your evaluation)

10

TOTAL

Basic Requirements of Projects

The policy to choose the project topic: 1) you can choose any one of the topics from

my project lists in ¡°project discussion I, II, III¡±. However, any topic can only be

chosen by one team. ¡°first come first serve¡± . The group that emails the team

member and title information to leluo@iupui.edu earlier will get the topic.

2) you can choose your own topic. However, you need to present the basic idea of

your topic in ¡°project discussion I, II, III¡±, and get approval from me.

3) In any case, you need to email your team member and title information to

leluo@iupui.edu before Apr.15 to secure a presentation time slot.

4) The maximum number of people for each team is three.

To get good credits for your report, the report should have at least 20,000

characters, which is roughly 5 pages of letter size paper. The due time of the

report is the time you give the presentation. There is no extension.

100

Projects for Discussion

Today's Projects for Discussion:

a) Modern Physics ©\©\ Modern Physics Researches at IUPUI

b) Modern Experiments for Testing Special Relativity

c) Quantization of thermal radiation: Blackbody Radiation

d) Quantization of gravity: Gravitational Wave, Gravitions and the

LIGO Project

e) Project selected by you!

Each presentation is 20 minutes (15 minutes talk plus 5 minutes questions).

There is no extension time or make©\up time. Without reserving a time slot

and giving a talk, the presentation credit is zero.

1

Modern Physics Researches at IUPUI

Faculty in the physics department at IUPUI conduct

theoretical and experimental investigations in many areas

of modern physics, such as biophysics, atomic, molecular

and optical physics, condensed matter/materials physics,

the fundamental forces of nature, and physics education.

Modern Physics Researches at IUPUI

Note: We have five areas of research. For AMO physics, you need to choose other

faculty instead of me for interview! ( I will have a lab tour for the whole class

later on)

Atomic, Molecular and Optical Physics

Le Luo

Zhe©\Yu Jeff Ou

Gautam Vemuri

Tony Lee

Biological Physics

Marvin D. Kemple

Horia Petrache

Steve Press¨¦

Stephen Wassall

Fangqiang Zhu

Condensed Matter Physics

Ruihua Cheng

Ricardo Decca

Yogesh N Joglekar

Physics Education

Andrew Gavrin



Projects: You need to interview at least one of the

faculty in each of the five category to get knowledge

of their research. Based on these interviews, you

write a report about modern physics researches at

IUPUI from your own perspective of view.

Projects for Discussion

Today's Projects for Discussion:

a) Modern Physics ©\©\ Modern Physics Researches at IUPUI

b) Modern Experiments for Testing Special Relativity

c) Quantization of thermal radiation: Blackbody Radiation

d) Quantization of gravity: Gravitational Wave, Gravitions and the

LIGO Project

e) Project selected by you!

Modern Experiments for Testing Special Relativity

Projects: You can make an investigation of modern

experiments of testing special relativity, and choose

2~3 experiments to write a review. Here I require you

to investigate experiments implemented after 1980s

(including 1980s), which are more precise experiments

including modern technologies.

Some experiments are listed below.

2

Modern Experiments to Test Special Relativity

Early experiments (pre-1905):

Round-trip tests of light speed isotropy: Michelson and Morley, Kennedy and

Thorndike.

Experiments (after 1905):

One-way tests of light speed isotropy: Cialdea, Krisher, Champeny,

Turner & Hill.

Tests of light speed from moving sources: Cosmological sources by

DeSitter and Brecher; Terrestrial sources by Alvaeger and Sadeh.

Measurements of the speed of light and other limits on it: NBS

measurements, 1983 Redefinition of the meter, Limits on variations

with frequency, Limits on photon mass.

Tests of the principle of relativity and Lorentz invariance: Trouton and

Noble.

Tests of the isotropy of space: Hughes-Drever, Prestage, Lamoreaux,

Chupp, Phillips, Brillet and Hall.

Overview: Experimental Tests of SR

SR makes many predictions, which are well tested:

¨C Isotropy of the speed of light ¨C 42

¨C Isotropy of space ¨C 8

¨C Constancy of the speed of light ¨C 12

¨C Time dilation and Doppler ¨C 16

¨C Length contraction ¨C ZERO

¨C Twin paradox ¨C 5

¨C Relativistic kinematics ¨C 23

¨C Relativistic velocity addition ¨C 5

¨C Variation of c with frequency ¨C 4

¨C Other ¨C 14

Modern Experiments to Test Special Relativity

Tests of time dilation and transverse Doppler effect: Ives and Stilwell,

Particle lifetimes, Doppler shift measurements.

Tests of the twin paradox: Haefle and Keating, Vessot et al, Alley,

Bailey et al., The clock hypothesis.

Tests of relativistic kinematics: Elastic scattering, Limits of velocity c,

Relativistic mass Variations, Calorimetric test of SR.

Other experiments: Fizeau, Sagnac, Michelson and Gale, g-2 tests of

SR, The global positioning system (GPS), Lunar laser ranging,

Cosmic background radiation (CMBR), Constancy of physical

constants¡­

An excellent source of information on experimental tests of

Special Relativity is the webpage:



Michelson ¨C Morley Experiment (1887)

Mirror

Beam

Splitter

Telescope

Mirror

Observer

*

Light Source

? Finicky experiment: ¡À0.002 ¡ãC, mechanical stability ~nm/m

? Result: upper limit of 7.5 km/s (earth relative to aether)

Michelson and Morley, Am. J. Sci. 34, 333 (1887).

3

Brillet and Hall Experiment (1979)

Single-Mode Laser

Frequency

Counter

Heterodyne

Single-Mode

Laser

Speed of Light Emitted by Moving Sources

As a simple test theory, assume the observed speed of

light is given by

Vobs = c + k Vsource

with k to be determined by experiment.

High-Finesse

Fabry-Perot

1) A test at CERN using ¦Ð0 decay:

k < 4¡¤10-4

Rotating Table

? Vastly less finicky than Michelson-Morley

Brillet and Hall,

Phys. Rev. Lett. 42, 549 (1979)

¨C Invar components with low thermal expansion

¨C Rotating Fabry-Perot etalon is vacuum

¨C Uses frequency (motion 1 wavelength/sec => 1 Hz, ~1 part in 1015)

? Result: ?f/f = (1.5¡À2.5) ¡¤10-15 =>

2) Distant supernovas have a velocity spread of the

remnants ~10,000 km/s (obtained via Doppler

broadening). Observations of supernovas ~5 billion light

years away show the light reaches us within ~10 days:

k < 10-9

Vearth < 0.02 km/s

Particle Experiment Tests of SR

? Today particle physicists test SR.

¨C Electron kinetic energy as a function of speed agrees

with the prediction of SR to within ~1% (1939)

Elastic Proton-Proton Scattering

Newtonian mechanics predicts in

the lab frame the scattered

particles will have an angle of 90¡ã.

For high-energy protons that is manifestly not so:

¨C The Lorentz limiting speed is equal to the speed of

light to within 12 parts per million (1972-1991).

¨C Super Kamiokande neutrino oscillation observations

put a limit of 10-24 on the speed difference between ¦Í¦Ì

and ¦Í¦Ó.

This experiment verified the kinematics of elastic scattering to about ?%,

for incident protons from 5 to 13.4 GeV/c (v/c=0.98 - 0.998).

Akerlof et al, Phys. Rev. 159, 1138 (1967).

4

Time Dilation in 7Li+ Ion Storage Ring

Electron-cooled

Ion Storage Ring

v/c = 0.064

Half-silvered

Mirrors

Time Dilation in atomic clock

Mirror

Fixed laser

Detectors

Tunable laser

Freq. Monitor



? Fixed laser is locked to a double resonance of the 7Li+ ions

with its parallel and anti-parallel laser beams.

? Parallel alignment of beams to 70 ¦Ìrad.

? 7Li+ linewidth is large, so the fixed laser saturates the

resonance and the tunable laser scans it to achieve resolution

comparable to the laser linewidths

? Measurement/SR = 0.9999999995 ¡À 0.0000000018

Saathoff et al, Phys. Rev. Lett. 91, 190403 (2003).

Visibly Superluminal Astronomical Sources

Projects for Discussion

? There are numerous astronomical objects observed to

have visible speeds greater than c.

Today's Projects for Discussion:

? In 1994 GRS 1915+105 was observed to emit material

a) Modern Physics -- Modern Physics Researches at IUPUI

b) Modern Experiments for Testing Special Relativity

c) Quantization of thermal radiation: Blackbody Radiation

d) Quantization of gravity: Gravitational Wave, Gravitions and

the LIGO Project

e) Project selected by you!

about the mass of the moon, with an apparent speed of

1.25 c (distance times angular speed). The uncertainty in

its distance (40,000 ly) is much less than 25%.

5

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