Einstein is quite possibly the most well known if not the most well known scientist in all of conceivable history. His calculation's of mass-energy equivalence and his three laws of relativity changed our way of thinking and are the grandfather principle's in quantum mechanic's and physics. He was one of the greatest minds of his time and contrary to popular conception, he had no belief in a personal god like the religious of today. Rather, he believed in an all-powerful deity. This aside, Einstein's quest in life would be to learn as much of the world as possible, just like all great scientist's. Ironically enough, his greatest theory*¹, mass-energy equivalence would become his most misquoted and terribly recognized scientific law ever.
Mass-energy equivalence at its core means this, as you add energy in any form to any object, the object will increase in mass and thus its inertia and weight accordingly, even though no matter has been observably added. A physical system has two properties, those being energy and mass respectively. The two properties are equivalent in a way in that they are always both present in a constant proportion to one another. Mass-energy equivalence was a theory put forward by Einstein which originated from one of his theories on special relativity. This simple form of equivalence is represented by the most common formula to date;
Figure 1: A full explanation of mass-energy equivalence and the standard units for each value in the formula.
Not only was he a great scientist, but he was nationally recognized as one by receiving a Nobel Prize for his theory of the Photoelectric Effect. Whilst it's one of his lesser known theories, the Photoelectric Effect further revolutionized the concept and actualization of Quantum mechanics. The Photoelectric Effect is the observation and theory that states that many metals can and will emit electrons when light shines upon them. Electrons emitted in this fashion are often referred to as photoelectrons.
According to classical electromagnetic theory (classical being contemporary physics i.e. the common sense stuff that day to day people think about, before the evolution of quantum mechanics), this effect can be attributed to the transfer of energy from the light to an electron in the metal. At this perspective, a slight change in wavelength or amplitude of light would cause changes in the rate of emission of electrons from the metal. Even further, according to this line of thinking, a sufficiently dim light would be expected to show a lag time between the initial shining of its light and the subsequent emission of an electron. The experiment results however did not correlate with either of the two predictions from this theory.
In actuality, electrons only become dislodged by the photoelectric effect if light reaches or exceeds a threshold frequency, below which no electron will be emitted regardless of the temporal length of exposure or amplitude of the light. To properly make sense of the this and explain it clearly, Einstein proposed that a beam of light is not a wave propagating through space, but rather a collection of discrete wave packets (photons), each with energy hf. This shed light on Max Planck's precious discovery of the Planck reaction (E = hf), linking energy (E) and frequency (f) as rising from quanization of energy. The factor h is known as the Planck constant.
Figure 2: The photoelectric effect as proposed by Einstein.
As great as these theories are, they're not the reason I made this post. Instead, it was to talk about why he's my idol and inspiration in the pursuit of knowledge. Einstein was a man of science, plain and simple. Even the second world war didn't stop him from looking even further into quantum science. He always stood by his theories and never doubted himself. He beseeched others to look forward and question everything they knew about the observable universe and more. He was a visionary and a forward thinker. He never put down anyone for their intelligence levels, as noted in his most overused quote in modern media "Everyone is a genius. But if you judge a fish by its ability to climb a tree it will live its whole life believing it is stupid." He is the kind of man I myself wish to be and someday may even become a similar man.
Glossary
Theory*¹ - A theory in a scientific context is an idea that has been proven through observation, verifiable and repeatable results, ruthless peer review, accurate measurement, taking into account of all new and old discoveries, and willingness to change with new evidence. Most theories, like gravity and evolution, are scientific law. There is absolute evidence in the matter of those theories and thus haven't needed to change over the centuries (Gravity being a 400 year-old theory and Evolution being a 200 year-old theory).
