Albert Einstein

Albert Einstein

The brilliance of this man, in my opinion, was that he was unrelentingly curious and was never satisfied until he was certain. Time and time again he turned the scientific world upside down and forced the greatest intellects of his time to do the same. A genius among geniuses.

Brownian Motion - Proving molecules exist

In 1905, Einstein wondered why no one had proven the existence of molecules. Pretty much every scientist of the day knew molecules must exist, but nobody had ever proven it. Einstein took interest in the work of a botanist named Robert Brown who, in 1827, looked through a microscope and noticed pollen grains bouncing around in water with no detectable force causing the motion. Einstein thought this motion must be caused by the seemingly random motion of water molecules interacting with the pollen. So Einstein did the very complicated math that explained in precise detail how the motion that Brown had observed was a result of the pollen grains being moved by interaction with water molecules. This explanation of Brownian motion served as the first definitive confirmation that molecules, and therefore atoms, actually exist. Further, this mathematical formula is used today to predict fluctuations in stock markets. Some other dude won the Nobel Prize for this in 1926 for some reason, but Einstein kept rocking.

Photoelectric Effect - Light is a wave, but it's also a particle

1905 was a big year for my man Einstein. He published another paper which solved another vexing problem for scientists of the day. Light had previously been thought of as a continuous wave, because, well, that's exactly what it looks like. But Einstein had the radical realization that light actually exhibits both wave and particle properties and individual 'packets' of light could be thought of as photons. With this discovery, the value of the energy of individual photons could be simply expressed as a function of its frequency. Sounds kind of boring, but without this discovery, you wouldn't be looking at your computer screen right now. You also wouldn't have TV, X-ray machines, night-vision goggles, and the moon landing would have failed badly. He won the Nobel Prize for this one in 1921.

Critical Opalescence - Let me tell you why the sky is really blue

In 1910, Einstein proved why the sky is blue. Previously two other dudes, John Tyndall and Lord Rayleigh thought that the blue colour of the sky must be due to small particles of dust and droplets of water vapour in the atmosphere that scatter shorter blue wavelengths more strongly than the red, ergo the blue sky. They were close, but if that were true, then the sky would be a different color on more humid days, and it isn't. So Einstein came along and suggested that it was the actual molecules of oxygen and nitrogen that caused the scattering and he calculated the formula that showed why. Many people today still think it's the scattering of light from the water vapor in the air that causes the blue sky. Now you can correct them.

Special Relativity - Your Aether is bullshit man

1905's big contribution by Einstein was the Theory of Special Relativity. Almost every scientist of his time thought that light moved through some mysterious substance called Aether and they were trying to find it. While they were doing that, Einstein thought the whole Aether just didn't add up. But there way something really weird with light; no matter how you measured it, it's always the same velocity. If you're moving toward a beam of light (should increase the observed velocity) or moving away from a beam of light (should decrease its observed velocity) it always measured the same velocity. That's why scientists thought there must be some stuff light travels in to resolve this paradox. But Einstein concluded that the speed of light was constant by any reference point. Whoa. This simple idea changed science forever. This idea inexorably links space and time by virtue of having a cosmic speed limit. As a result, a wide range of consequences must occur, including: time dilation (the twin paradox), mass-energy equivalence (E = mc2), and the relativity of simultaneity (the same event happens at different times depending on your reference point). This theory might be considered the starting point of modern physics.

Relativity of Simultaneity - Your point of view isn't mine

A consequence of Special Relativity is that it is impossible to say if two events occurred at the same time if those events are separated by space. Einstein's train thought experiment is awesome: A man is on a train when three things happen simultaneously; lightning strikes the front of the train, lightning strikes the back of the train, and the moving passenger passes exactly in front of a man on the platform. The man on the platform doesn't see it that way at all. The man on the platform will first see the lightning strike the front of the train, then come face to face with the moving passenger, then see the lightning hit the back of the train. This effect magnifies as the speed of the train increases. Inertial frames of reference define your idea of time.

General Relativity - Euclidean geometry, you're so passé.

After Einstein published Special Relativity in 1905, it changed everything in physics, and physicists everywhere tried to determine it's consequences to different fields. It worked amazingly well until it squared up with Newton's Law of Gravity. According to Newton, the sun exerts a force on the earth such that if the sun were to be moved a bit, that movement would be felt on Earth at the same time as the sun was moved. But according to Special Relativity, it shouldn't because there is no such thing as absolute simultaneity; observers in different reference points observe things differently, especially when the observers are moving with great speed relative to one another. Up until now, humans thought of the physical world in terms of 3 dimensions that were linear, light being the most obvious phenomena (light always travels in straight lines). But scientists always knew there was a problem as measurements on a cosmic scale showed small discrepancies. It was when Einstein considered small fluctuations in Mercury's orbit, that he made the connection. Gravity itself bends space-time. In 1915, he published the Theory of General Relativity. Gravity isn't just a force, it's a geometric property of the Universe. The more massive the object, the more space-time is bent. This was a pretty shocking thing to suggest, and it was almost impossible to prove, since we mere mortals are condemned to our 3-D existence. But General Relativity predicted that during an eclipse, the light from the sun should bend around the object eclipsing the sun. Einstein challenged astronomers to prove him wrong, and in 1919, the gravitational deflection of starlight was observed by two separate teams in Brazil and Principe.

The implications of General Relativity are astounding, and it is considered 'one of the greatest feats of human thinking about nature' (Max Born - fellow Nobel laureate). It explains why planets revolve around stars and it predicted black holes, gravitational lensing, red-shifting of objects, dark matter, the expansion of the universe and other notions, all proven true, that have greatly expanded our knowledge of the universe.

tl;dr Einstein was a badass. This is an update of a previous post I made hastily. Hope you enjoyed.