In 1900, Max Planck, in trying to understand the mathematical principles behind blackbody radiation, postulated that energy was not continuous, but came in discrete amounts.
He admitted that this was a mathematical trick to make the model fit observations.
Nonetheless, his idea, of energy being quantised, was taken up by Albert Einstein to explain the Photoelectric Effect. Later it was taken up by Niels Bohr to understand the structure of the atom.
What was a 'mathematical trick' led to complete paradigms shift what is now known as Quantum Mechanics.
The following lessons explore the development from Max Plank to Schrödinger and Heisenberg.
He admitted that this was a mathematical trick to make the model fit observations.
Nonetheless, his idea, of energy being quantised, was taken up by Albert Einstein to explain the Photoelectric Effect. Later it was taken up by Niels Bohr to understand the structure of the atom.
What was a 'mathematical trick' led to complete paradigms shift what is now known as Quantum Mechanics.
The following lessons explore the development from Max Plank to Schrödinger and Heisenberg.
1. Black Bodies and Planck
video
worked solution
going deeper
interactive
video
|
|
This video covers the basics of the back body curve, and Planck's attempt to reconcile the observations with the current theories. His attempt led to the birth of quantum physics |
|
|
A quick review on Blackbody Radiation, useful for review
|
worked solution
going deeper
interactive
2. Photoelectric Effect Explained
video
worked solution
extra videos
interactive
Quiz
video
|
|
On the back of Planck's attempt to reconcile classical physics and blackbody radiation , and the anomalous observations from Philip Lenard, Einstein comes up with a radical explanation for light and in doing so ushers in the idea of the wave-particle duality of light
|
worked solution
|
|
|
extra videos
|
|
|
Two videos (one basic, one more detailed done in collaboration with University of Sydney Kickstart and CrookED Science
|
|
This brief video addresses a common error when trying to understand the photoelectric effect and it has to do with the meaning of intensity
|
|
|
A summary of the photoelectric effect, useful for review
|
interactive
Quiz
3. The Bohr model
video
worked solution
pHET
interactive
video
|
|
After the Rutherford experiment which establish a planetary model for the atom, the problem existed as to why electrons stay in orbit. Bohr introduced quantum understanding to solve this problem
|
worked solution
pHET
This pHET animation allows you to compare the different models of the Hydrogen atom, starting from JJ Thomson's plum pudding model to Schrödinger (NB: this will only work on computers and not iPads
interactive
4. De Broglie and the introduction of matter-wave duality
video
worked solution
interactive
video
|
|
De Broglie introduced a radical idea why electrons stay in set orbits In this video I examine a useful demonstration to help understand the wavelike nature of the electron.
|
worked solution
|
|
|
interactive
This animation looks that the standing waves that De Broglie hypothesised for the Bohr atom. By Tom Walsh
5. The experiment that demonstrated that electrons act like waved
video
worked solution
going deeper
resources
video
|
|
Davisson and Germer do diffraction with electrons |
worked solution
going deeper
There are a number of ways we can explore this concepts further.
One aspect of most high school physics course on kinematics, is that they only concern themselves with constant acceleration. In reality however, acceleration, like displacement and velocity, can chance with respect to time.
Velocity is the rate of change of displacement. Unit: m/s2
Acceleration is the rate of change of velocity.
So what is the rate of change of acceleration?
The answer to that is the jerk. So slope of the acceleration vs time graph is the jerk. Unit: m/s3
We can go further.
What is the rate of change of the jerk?
Well it's the snap. Unit: m/s4
Can we go further? Yep. The rate of change of snap is the crackle. Unit: m/s5
I think you can guess the next one.
resources
- pHET graphing animation - this interactive from the University of Colorado pHet team is a great way to demonstrate the relationship between motion and its graphical analysis. That why I used it in my video. At this time its Java based so will only work on PC/Mac
6. Compton scattering
video
derivation
resources
video
|
|
Compton scattering is the effect of photons of rays scattering electrons, and provided evidence for the. particle nature of light. This video covers an explanation and the mathematical relationship that Arthur Compton derived by assuming a quantum nature and conservations laws.
|
derivation
|
|
Compton's scattering Formula looks at the relationship between xray photons wavelengths and the angle of interaction with electrons. How is it derived?
|
resources
7. Schrödinger's Equation
video
more problems
resources
video
|
|
Schrödinger's Equation is fundamental to the quantum behaviour of the atom, and quantum mechanics in general. But what is it all about? In this video I discuss what it means, without delving too deeply in the mathematics, and how it helps understand the nature of the electron in the atom. |
more problems
resources
8. Heisenberg Uncertainty Principle
video
worked solution
going deeper
resources
video
|
|
What is the Uncertainly Principle and why it underpins Quantum physics |
worked solution
going deeper
resources
9. How a laser works
video
going deeper
video
|
|
Lasers have unique properties - light that is monochromatic, coherent and collimated. But why? and what is the meaning behind he term laser. This video covers are fairly comprehensive explanation of the process of producing a laser beam.
|
going deeper
