Photoelectric Effect and light as a particle

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Discussion Overview

The discussion centers around the nature of light, specifically addressing why light exhibits particle-like behavior in the Photoelectric Effect while demonstrating wave-like characteristics in Thomas Young's Double Slit Experiment. Participants explore theoretical implications and seek resources for further study, including books and papers related to the topic.

Discussion Character

  • Exploratory
  • Technical explanation
  • Homework-related

Main Points Raised

  • One participant questions the dual nature of light, asking why it behaves as a particle in the Photoelectric Effect and as a wave in the Double Slit Experiment.
  • Another participant explains that the photoelectric effect demonstrates light's particle nature because a single photon must possess sufficient energy to eject an electron, indicating that photons are discrete entities.
  • Discussion includes the concept that all matter exhibits wave-like properties, referencing the de Broglie wavelength, which becomes significant for low momentum particles.
  • A participant expresses the need for detailed references to support a paper on light's dual nature, specifically regarding the photoelectric effect.
  • Participants share links to Einstein's original paper on the photoelectric effect and other resources that discuss the phenomenon without relying on the concept of photons.
  • One participant outlines their research plan for a paper, listing various topics and resources related to the wave-particle duality of light.
  • A later reply offers encouragement and notes the importance of adhering to forum rules regarding self-referencing in academic work.

Areas of Agreement / Disagreement

Participants express varying viewpoints on the interpretation of light's behavior, with some emphasizing the particle aspect in the context of the photoelectric effect and others discussing wave properties. No consensus is reached regarding the overall nature of light, and multiple competing views remain present.

Contextual Notes

Participants reference various theoretical frameworks and experiments, but the discussion does not resolve the complexities surrounding the definitions of light as a particle or wave. Limitations in assumptions and the dependence on specific definitions are acknowledged but not fully explored.

Who May Find This Useful

This discussion may be of interest to students and researchers exploring the fundamental nature of light, particularly in the context of quantum mechanics and wave-particle duality.

Cmertin
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I have a question, why does light act like a particle during the Photoelectric Effect Experiment, but acts as a wave in Thomas Young's Double Slit Experiment? Does anyone have a good book that I could rent in the Library or find on Questia.com or find online that I could use to read up on this?
 
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Do you mean why does the photoelectric effect show that light is a particle?
For the photon to eject an electron there must be enough energy in a single photon - you can't use lots and lots of lower energy ones.
This proves that photons are discrete.

The wave part is more interesting. Photons don't behave like waves - everything does! Even elephants defract through a slit. But the wavelength decreases with increasing momentum so it's only noticable with very low momentum particles such as massless photons or low mass particles like electrons
It's called the de Broglie wavelength
 
Yes, I meant why the photoelectric effect shows that light is a particle? I have to write a 4,000 word paper on whether light is a particle or wave, and I have the "waviness" (DeBroglie Hypothesis/Wavelength). I need a work though that explains in greater detail about the photoelectric effect.
 
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Thanks for your guy's help, those look like good/solid references for my paper. And Phrack, I thank you personally because I was looking for that but couldn't find it.

I found a site on how to conduct a cheap $100 photoelectric experiment (with LED's) and my teacher has all the materials for Young's Double Slit Experiment. Right now I just have to make an outline and an annotated Bibliography (haven't done any of the labs yet) before school starts on Aug. 25.

Does anyone know what I could put in it? This is what I have so far (it's in no specific order and the sources that you guys gave me are not added yet because I have to go tutor):
Question that I have to answer: Is light a particle or wave and what effects it and why?

• Thomas Young’s Double Slit Experiment
o http://www.glenbrook.k12.il.us/gbssci/phys/Class/light/u12l3d.html

• Photoelectric Effect Experiment

• De Broglie Hypothesis
o De Broglie Wavelength
http://hyperphysics.phy-astr.gsu.edu/hbase/mod1.html

• explanation of Photoelectric Effect
o Why it acts as a particle
 Photons and threshold freqency
 “The photoelectric effect is the emission of photoelectrons from a clean metal surface due to incident light whose frequency is greater than a threshold frequency. The photoelectric effect supports the particle theory of light because it shows that the energy required to release electrons from a metal is totally dependent upon the frequency of the light, and not the intensity. Therefore, certain frequencies of light, no matter how intense, cannot cause an electron to be emitted from the surface of a metal”

• Wave-Particle Duality
o http://physics.about.com/od/lightoptics/a/waveparticle.htm

• Background Information
o http://physics.weber.edu/carroll/honors-time/duality.htm
 
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I'd read your paper once you finish and referenced it on the physics forum. Though I'm not sure you are allowed, personally, to link to your own material per PF rules.
 

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