Appendix B

Unveiling the Absurd
(Quantum Mechanics Part 2)

“Quantum mechanics describes nature as absurd
from the point of view of common sense.
And it fully agrees with experiment.
So I hope you can accept nature
as She is — absurd.
~ Richard Feynman

Don’t Sweat the Small Stuff
Unless You Want To Know What’s Going On Around Here

Yes, I’m continuing to bother you with quantum mechanics. The conflict between quantum mechanics and general relativity has generated a whole new set of speculations about gravity. So it’s good to have a grip on this quantum stuff because it helps when you look at this new generation of ideas about gravity (and a theory of everything).

Remember, in the chapters on relativity, when I used the quote “This will feel a little weird”? Well, if special and general relativity felt a little weird, hold onto your hat. Experiments showed that the quantum world is beyond weird. It’s absurd. From the point of view of common sense, you could even call it deranged.

Let’s look at how real-world experiments revealed the absurdity of how these quantum particles of matter and force behave. It started in 1801 with what is called the double-slit experiment, performed by Thomas Young. In the book, I go into quite a bit of detail to explain the experiment and what it tells us about the real world.

This and other experimental results throughout the 1800s went beyond breaking the idea of matter and force into quantum particles. The results showed that these quantum particles exist in bizarre states and interact in strange ways.

It came to a head with an experiment in 1887 by Heinrich Hertz. The results demonstrated that the interaction of photons and electrons does not follow how classical physics says light and matter should interact. Einstein took those results, plus the studies of Brownian Motion, and other experiments, and published some papers in 1905 that dropped the bottom out of Newtonian physics.

The implications were immense. It took dozens of scientists decades of work to sort the mess out. In the end, quantum mechanics revealed the specific list of the elementary particles that our universe is composed of. All of these truly elementary particles have been experimentally verified. But beyond that, quantum mechanics described the bizarre wave/particle and probability/uncertainty nature of the quantum particles of matter and force. Check out Appendix B for plain English descriptions of some of the most mind-bending aspects of the quantum world.

The activity at the end of this chapter is my favorite in the whole book. It lets you demonstrate the quantum particles of light (photons) travel as a wave. And yet, other experiments clearly show that light interacts with other particles as a particle.

So are photons particles or are they waves?

Yes.

You can do the double-slit experiment in the comfort of your own home!


Activity Video for Appendix B


Here are the links from the text in Appendix B:

119. Great Video “Pilot Wave Theory and Quantum Realism | Space Time – YouTube.” 30 Nov. 2016,
https://www.youtube.com/watch?v=RlXdsyctD50
Warning: Starts with ads.

120. Deeper Dive “atom – Discovery of electrons – Encyclopedia Britannica.”
https://www.britannica.com/science/atom/Discovery-of-electrons

121. Deeper Dive “Photoelectric effect – Wikipedia.” 
https://en.wikipedia.org/wiki/Photoelectric_effect

122. Deeper Dive “History of quantum mechanics – Wikipedia.”
https://en.wikipedia.org/wiki/History_of_quantum_mechanics

123. Great Video “Photoelectric effect Demonstration”
https://www.youtube.com/watch?v=v-1zjdUTu0o
Warning: Starts with ads.

124. Biography “Anders Jonas Ångström – Wikipedia.”
https://en.wikipedia.org/wiki/Anders_Jonas_%C3%85ngstr%C3%B6m

125. Biography “Niels Bohr | Biography, Education, Accomplishments, & Facts.”
https://www.britannica.com/biography/Niels-Bohr

126. Deeper Dive “Bohr model – Wikipedia.” 
https://en.wikipedia.org/wiki/Bohr_model

127. Deeper Dive “Corpuscular theory of light – Wikipedia.”
https://en.wikipedia.org/wiki/Corpuscular_theory_of_light 

128. Biography “Augustin-Jean Fresnel | French physicist | Britannica.”
https://www.britannica.com/biography/Augustin-Jean-Fresnel

129. Deeper Dive “Light – Young’s double-slit experiment | Britannica.”
https://www.britannica.com/science/light/Youngs-double-slit-experiment

130. Physics-Speak “Davisson–Germer experiment – Wikipedia.”
https://en.wikipedia.org/wiki/Davisson%E2%80%93Germer_experiment

131. Biography “Werner Heisenberg | Biography, Nobel Prize, & Facts | Britannica.” 28 Jan. 2022,
https://www.britannica.com/biography/Werner-Heisenberg

132. Biography “Erwin Schrödinger – Wikipedia.”
https://en.wikipedia.org/wiki/Erwin_Schr%C3%B6dinger

133. Biography “Paul A.M. Dirac – Biographical – NobelPrize.org.”
https://www.nobelprize.org/prizes/physics/1933/dirac/biographical/

134. Deeper Dive “Harmonic – Wikipedia.” 
https://en.wikipedia.org/wiki/Harmonic

135. Great Video/Physics-Speak “Understanding Quantum Mechanics #7: Atomic Energy Levels.” 7 Nov. 2020,
https://www.youtube.com/watch?v=LBTNKzZLo-s

136. Deeper Dive “Atomic orbital – Wikipedia.” 
https://en.wikipedia.org/wiki/Atomic_orbital

137. Great Video “Is The Wave Function The Building Block of Reality? | Season 8 ….” 15 May. 2022,
https://www.pbs.org/video/is-the-wave-function-the-building-block-of-reality-1ehzgu/
Warning: Starts with ads.

138. Deeper Dive “Standard Model – Wikipedia.” 
https://en.wikipedia.org/wiki/Standard_Model

139. Deeper Dive “Uncertainty principle – Wikipedia.”
https://en.wikipedia.org/wiki/Uncertainty_principle