Professor Dave explains modern physics

Introduction

From Newton’s classical mechanics to Maxwell’s classical electromagnetism, it seemed that we knew everthing there was to know about physics.
The universe appeared to be deterministic. If we knew just the location and momentum of every particle in a system, it was possible to know the system’s state at any given time.
- This persisted until the begin of the 20th century, where this idea started falling apart.
We realized that classical physics worked for most earthly phenomena, but when taking care of the tiniest bit of matter, or even the fastest, it broke down.
Modern physics was the biggest paradigm shift in the history of science.

The shift initieted in 1901, as Max Planck had solved the ultraviolet catastrophe.

Blackbodies emit electromagnetic radiation of all wavelengths. Eg. Sun, piece of metal really hot.
Most of the sun’s emition is on the visible espectrum, but it emits a tiny portion of UV and Infrared and smaller frequencies.
The blackbody spectrum depends only on temperature.
At around 4000K and above, the object will emit mostly visible light.
Classical theory couldn’t account for this distribuition.
- It predicted that shorter wavelenths, would increse to infinity. As in reality there was the UV portion of the spectrum.
This got known as Ultraviolet Catastrophe
It was stated that classical electromagnetism must be incomplete
Planck solved this problem by implementing quantization
Planck proposed that the vibration energies of the atoms are quantized.
Meaning energy was discrete, only being able to take up certain values from a set of accepted values
Planck then, developed the equation below, where n can be any integer, [\h=6.626/cdot 10^-34J/cdot s\] AKA Planck’s constant, and f the frequency of radiation

\[\E = nhf\]

N results in quantization, because it can only take up integer numbers
However, this explanation was only used in ad hoc manner, but it allowed for the correct math to line up with the observation, at all wavelengths.
Seeing how small the planck constant is, makes you realize why we haven’t seen it coming: energy is quantized on the tiniest of scales, hence its gradations fadded, so as to appear non-existent.
This was the first time quantization would take place in solving a big physics problem.