Albert Einstein and His Contributions to Physics

Study Notes

Named after Robert Brown, a Scottish botanist
Einstein wrote an influential paper on it in 1905 while working as a patent clerk.
Brownian motion was first observed in 1827
Einstein showed that the existence of atoms, in constant motion, correctly explains Brownian Motion.

First documented in 1887 by Heinrich Hertz and later by Lenard in 1902.
Einstein theorized that light is bundled into photons that transfer all of their energy to electrons when they hit a metal surface.
The Photoelectric Effect occurs when electrons are emitted from a metal surface when light of sufficient frequency shines on it.
Part of the photon's energy is used to release the electron from the atom and the rest is given to the ejected electron as kinetic energy.
The minimum energy requirement for the photoelectric effect is 3.0895471249137887 eV or 4.95 x 10-19 J

The theory of special relativity shows that mass and energy are the same physical entity and can be converted into one another.
The equation states that the increased relativistic mass of a body multiplied by the speed of light squared is equal to the kinetic energy of that body (E = mc2).
There are three philosophical questions concerning the interpretation of E = mc2 that have occupied philosophers and physicists:
- Are mass and energy fundamentally the same property of physical systems?
- Is mass "converted" to energy in physical processes, and if so, what is the nature of this "conversion"?
- Does E = mc2 have any implications about the underlying nature of reality? (ontological consequences)

Published in 1915.
Known as the general theory of relativity or Einstein's theory of gravity.
It is a geometric theory of gravitation that provides the current description of gravitation in modern physics.
It generalizes special relativity and refines Newton's law of universal gravitation.
It describes gravity as a geometric property of space and time (spacetime).

Published by Albert Einstein in 1905.
One of the most important scientific publications of all time.
It explains how speed affects mass, time, and space.
Approaching the speed of light causes an object’s mass to become infinite, as does the energy needed to move it.

It states that position and momentum of an electron cannot be measured simultaneously with absolute certainty.
The equation for the Heisenberg Uncertainty Principle is: ΔxΔp ≥ h/2π (Δx being the uncertainty in position, Δp being the uncertainty in momentum, and h being Planck's constant).

Einstein never accepted Heisenberg's Uncertainty Principle as a fundamental law of physics.
Although Einstein made critical contributions to quantum mechanics, he rejected the implications of the Uncertainty Principle.
He famously said: "God does not play dice with the universe”

Refers to the energy carried by atoms.
The term was first coined in 1903 by Ernest Rutherford.
The phrase "splitting the atom" was popularized by H.G. Wells before the discovery of the atomic nucleus.