liberal physics
n Greek mythology, Atlas was a Titan condemned to hold up the sky for eternity. (I don’t know why he ends up being depicted holding up the globe.)
This is undoubtedly a strenuous task requiring a large force. But since he is only holding up the sky, and the sky did not move, he is not doing any work to the sky.
W=F.s. No displacement, no work.
Couple: A pair of equal but opposite forces whose lines of action do not coincide.
A couple contribute zero net force, but a non-zero net moment. In fact, the moment it contributes is the same, regardless of the pivot point.
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.
Electrons moving in a magnetic field experiences a magnetic force F=Bqvsinθ.
In this comic, the electrons are learning how to avoid magnetic deflection, either by being stationary, or by moving parallel to the magnetic field. Haha.
Motional EMF (ε=BLv) occurs when a conductor “cuts the magnetic flux”.
In this comic, the wire in the middle is the only one moving perpendicularly to the magnetic field, resulting in induced EMF across its two ends. Haha.
Faraday’s Law (ε=-dΦ/dt) implies that a constant magnetic flux results in no induced EMF. EMF is induced only when there is a CHANGE in magnetic flux linkage.
In this comic, the elderly lady is not bothered by extreme temperatures. She is only bothered by CHANGEs in temperature. Haha.
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.
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.
In the Bohr’s atom, the electron can only occupy discrete energy levels, meaning the electrons must make quantum leaps from one energy level to another.
In this comic, the aircon has only two allowed temperature settings. The in-between temperatures are forbidden. Haha.
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.
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.
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.
xmComic 