0. Wave-Particle Duality An Investigation of Light
Shedding Light on
Wave-Particle Duality
Nicole Ozdowski
Samantha Candalor
Andrew Lingenfelter
Fernando Marill-Tabares
An Investigation of Light

1. Wave Theory of Light Aristotle (384–322 BC) [4th century BC]
Pythagoras ( BC)
[6th century BC]
I need to check if these centuries are correct

2. 17th Century:
Christiaan Huygens ( )
Isaac Newton ( )

3. 19th Century:
Thomas Young ( )
Augustin Fresnel ( )

4. 1861:
Proved that Electricity and Magnetism were expressions of the same thing.
Found the equality between an electromagnetic wave and light
James Clerk Maxwell ( )

5. Einstein’s Photoelectric Effect
Heinrich Hertz ( )
Heinrich Hertz
Albert Einstein ( )

6. Quantum Mechanics: Wave-Particle Duality
Both?

7. Interference
Constructive Interference
Destructive Interference

8. Young’s Double Slit Experiment
Δx = λD/a
Δxr = 0.47cm
Δxg = 0.40cm

9. Setting Up the Experiment
Light Sensor
and Single Slit
Laser and Double Slit

10. 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.

11. The Photoelectric Experiment

12. The Concept

13. Setting Up the Experiment
Mercury Lamp and Detector Amplifier and Meters

14. Results V=(h/e)*f Slope is equal to h/e h/e = -4.136*10-15 Js/C
Our slope = *10-15Js/C
The closeness of the two values confirms the photoelectric effect.
Conclusion:
Light acts as a particle.

15. 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.

16. Experimental Setup
Laser and Double Slit Photomultiplier tube

17. 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.

18. 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…

19. Light is a Wavicle.

20. Quantum Mechanics: Wave-Particle Duality
Light as a Wave:
Well defined momentum and wavelength
Position is spread out and unclear
Can interfere and diffract as a wave would
Light as a Particle:
Well defined position
Wavelength is unclear
Can slam into particles

21. 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

22. References