De Broglie’s Car Chase

1 de Broglie's Car Chase

According to de Broglie, every particle has an associated wavelength of λ=h/p. The larger the momentum, the shorter the wavelength.

In this comic, the car is desperately trying to increasing its speed and thus momentum, so as to shorten its wavelength, and hopefully avoid being diffracted when it drives through the slit. Haha.

Photoelectric Serenade

5 photoelectric serenade

Photoelectric Effect occurs only when the illuminating light exceeds the threshold frequency (so that the energy of each photon exceeds the work function of the metal).

In this comic, the guy can sing as loud as he can. But if his pitch is not high enough, the girl is not going be moved. Haha.

The Wave-Particle Face-off

6 nature of light debate

Is light a wave or a stream of particles? This has been debated for hundreds of years. From Newton’s Corpuscular Theory, to Huygen’s Principle. Young’s double slit experiment seemed to have settled matters, until Einstein’s photoelectric effect came along.

In this comic, pugilists from the wave and particle camps fight each other to the death, throwing deadly wave and particle weapons at each other. Haha.

Continuous Spectrum Violin

8 continuous spectrum violin

A hot solid emits light with a continuous spectrum, i.e. there is no gap in the spectrum, every wavelength is present. A hot gas on the other hand emits light with a discrete spectrum, i.e. only certain sharply defined wavelengths are present.

In this comic, the boy is struggling to play the correct notes because the violin is a “continuous spectrum instrument”. By pressing along the violin string, one can produce sounds of any pitch, including off tune notes. A piano on the other hand is a “discrete spectrum instrument”. It can only produce notes that the piano keys have been tuned to, and nothing in between. Haha.

The Banana Absorption Line

9 fruit absorption line

An absorption spectrum is obtained by shining white light through a dense gas. While most light passes through the dense gas, certain specific wavelengths (that correspond to the energy gaps in the gas atom’s quantized energy structure) are absorbed. The resulting spectrum is best described as dark lines in a continuous spectrum.

In this comic, only the bananas are “absorbed” by the monkey, resulting in gaps in the “fruit spectrum”. Haha.

Bremsstrahlung Car

10 bremsstrahlung car

A charged body undergoing acceleration (speed up, slow down, or change direction) must lose energy by emitting electromagnetic radiation. This is called the Bremsstrahlung radiation, which is the underlying cause for the background X-ray radiation.

In this comic, the car moving in a zig-zag manner is fined for accelerating, losing eV in the process. Haha.

Quantum Pay

17 Quantum Bill

Energy of a photon E=hc/λ is inversely proportional to wavelength.

For Gamma rays, energy is delivered in large energy bundles are a few MeV each.

For visible light, energy is delivered by photons that each carries a few eV.

Microwave photons are tiny energy bundles of a few μeV each.

In this comic, Gamma rays, visible light and microwave foot their bill with a million-dollar note, dollar notes, and petty coins respectively. Haha.


Photon Bomb

18 photo bomb

For photoelectric effect, changing the frequency of illuminating light means changing the quantum in which energy is delivered to the metal. Blue light delivers photons that pack more energy each compared to red light.

Photoelectric effect is the interaction between one electron and one photon. This explains why the higher the photon energy, the more energetic the ejected photoelectron. It also explains why there is a threshold frequency below which photoelectric effect cannot occur.

Photoelectric Sniper

20 photoelectric effect

Because light are particles, the photoelectric effect is a one-photon-one-electron interaction, and there is negligible delay between the arrival of the photons and the liberation of the first photoelectron.

If light were waves, the energy delivered must be shared by all the electrons. This ought to result in significant delay between the arrival of the photons and the liberation of the photoelectrons especially when low intensity light is used.

Spectral Line CSI

22 Spectral Line CSI

A hot gas emits light with an emission spectrum that consists of discrete lines. This is because the energy levels of a gas atom is quantized, meaning it is only capable of emitting photons with energy corresponding to the energy gaps between a pair of allowed energy levels.

Since the energy structure of each element is unique, the emission spectrum for each element is also unique. This forms the basis for spectroscopy whereby we identify the elements in a hot gas by mapping its emission spectrum to characteristic line spectrum of known elements.

In this comic, the detective identifies the murderer to be Sodium gas, whose characteristic line spectrum contains the famous bright doublet at 588.9950 and 589.5924 nanometers. Haha.

Electron Graduation Ceremony

23 electron graduation ceremony

In the electron diffraction experiment, electrons passing through slits are shown to form a diffraction pattern on a screen. Even though each electron lands at one specific spot on the screen (particle-like behavior), the landing position adheres to a probabilistic density function. So collectively, the electrons form a diffraction pattern (wave-like behavior).

In this comic, electrons walk through a slit at the graduation ceremony. Where each electron will be detected next beyond the slit is really up to chance. But collectively, they will concentrate at the “bright fringes” and be totally absent at the “dark fringes” of the single-slit diffraction pattern. Haha.