Download Shedding Light on Wave-Particle Duality - pgss

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts
no text concepts found
Transcript
Nicole Ozdowski
Samantha Candalor
Andrew Lingenfelter
Fernando Marill-Tabares
Wave Theory of Light
Aristotle (384–322 BC)
[4th century BC]
Pythagoras (570-495 BC)
[6th century BC]
17th Century:
Christiaan Huygens (1629-1695)
Isaac Newton (1642-1727)
19th Century:
Thomas Young (1773-1829)
Augustin Fresnel (1788-1827)
1861:
James Clerk Maxwell (1831-1879)
●
Proved that Electricity and
Magnetism were
expressions of the same
thing.
●
Found the equality
between an
electromagnetic wave and
light
Einstein’s Photoelectric Effect
Heinrich Hertz (1857-1894)
Albert Einstein (1879-1955)
Quantum Mechanics:
Wave-Particle Duality
Interference
Constructive Interference
Destructive Interference
Young’s Double Slit Experiment
Δx = λD/a
Δxr = 0.47cm
Δxg = 0.40cm
Setting Up the Experiment
Light Sensor
and Single Slit
Laser and
Double Slit
Results
Δxr,th = 0.47cm
Δxr,exp = 0.467cm
%error = 0.64%
Δxg,th = 0.40cm
Δxg,exp = 0.413cm
%error = 3.25%
Conclusion:
Light acts as a wave.
The Photoelectric Experiment
The Concept
Setting Up the Experiment
Mercury Lamp and Detector
Meters
Amplifier and
Results
●
V=(h/e)*f
●
Slope is equal to h/e
●
h/e = -4.136*10-15 Js/C
●
Our slope = -2.317*1015Js/C
The closeness of the two
values confirms the
photoelectric effect.
Conclusion:
Light acts as a particle.
Single Photon Detection
Double Slit Experiment
● Repeat the double slit
experiment
● Count photons instead of
measuring intensity
● If light is a wave then detector
won’t count
● If light is a particle, there won’t
be an interference pattern.
Experimental Setup
Laser and Double Slit
tube
Photomultiplier
Results
Theoretical ΔX:
0.2626 cm
Experimental
ΔX:
0.2622
cm
Error: 0.15%
Counts of Single Photons produce
an Interference Pattern.
Conclusion:
Light acts as a wave and a particle.
Conclusion
Is light a wave?
The double slit experiment says yes.
Is light a particle?
The photoelectric experiment says yes.
Is light both?
The photon detection experiment says
yes.
Therefore…
Light is a Wavicle.
Quantum Mechanics:
Wave-Particle Duality
Light as a Wave:
Light as a Particle:
● Well defined momentum
and wavelength
● Well defined position
● Position is spread out
and unclear
● Wavelength is unclear
● Can interfere and diffract
as a wave would
● Can slam into particles
Acknowledgments
Dr. Luokkala - PGSS Director
Patrick Diggins and Zach McDargh - Project Leaders
Patty Yoritomo - Project TA
Corporate and Private Sponsors
PGSS Alumni Association
PGSS Campaign
References
http://en.wikipedia.org/wiki/Thomas_Young_(scientist)#mediaviewer/File:Thomas_Young_(scientist).jpg
http://www.physicsoftheuniverse.com/images/quantum_double_slit.jpg
http://i.stack.imgur.com/Q4brH.gif
http://upload.wikimedia.org/wikipedia/commons/3/39/GodfreyKneller-IsaacNewton-1689.jpg
http://images.gizmag.com/hero/so-you-think-youre-confused-about-quantum-mechanics-9.jpg
http://www.scenicreflections.com/files/Marble_columns_Wallpaper_f3cq8.jpg
http://evlocker.files.wordpress.com/2012/10/2012-02-18.jpg
http://www.marius-riether.com/wp-content/uploads/2013/05/Particles1.jpg
http://www.quantumdiaries.org/wp-content/uploads/2011/07/feynman_qqGamee1.png
https://wiki.brown.edu/confluence/download/attachments/72637259/image003.Png
http://abyss.uoregon.edu/~js/21st_century_science/lectures/lec13.html
http://hdw.eweb4.com/wallpapers/8080/
http://www.faqs.org/docs/qp/chap03.html
http://en.wikipedia.org/wiki/Heinrich_Hertz
Related documents