Albert Einstein
and
His Discoveries
Zurich Polytechnic
Albert Einstein, a creative genius and the most celebrated theoretical physicists in the world, was born in Ulm, Germany in 1879. He grew up in Munich and studied physics & mathematics in Zurich Polytechnic in Switzerland.
1921 Nobel Prize
When we think of Albert Einstein, we think only of his Relativity Theory. Many of us may not even be aware of his other incredible contributions to physics such as the laws of photoelectric effect and the discovery of particle nature of light (photon) in 1905. His discovery on photoelectric effect was pivotal in opening a new field in physics – Quantum Mechanics.
Photoelectric Effect:
E=hν
In fact, he received the 1921 Nobel prize in physics for his discovery of the laws of photoelectric effect. The above equation is his discovery related to the law of photoelectric effect. In this equation, E stands for the energy of a photon, h is the Planck’s constant and ν (nu) is the frequency of the light wave.
Patent Clerk
After his graduation from Zurich Polytechnic, Einstein was not able to get any teaching job, nor any research position anywhere. But with the help of his friend, he found a clerical job in the patent office of Bern, Switzerland. While at the patent office, Einstein could spend substantial time on physics and research as the patent clerk job was not very demanding.
Annus Mirabilis (1905)
In the year 1905, while working as a patent clerk, Einstein published four papers that changed the world of physics. Each one was a masterpiece. Any one of these papers could have been enough to make a person great theoretical physicist. But he published four papers in the same year. No doubt, only a genius like Albert Einstein could do this feat.
Einstein published the following four papers in 1905:
- Special Theory of Relativity
- Photoelectric effect
- Brownian motion
- Mass energy equivalence.
Special Theory of Relativity
A common misconception of the Special Theory of Relativity is the assumption that the theory implies everything is relative. That is not the crucial point of the theory. In fact, Einstein considered calling his theory ‘Invariance theory’. But the name did not take hold in scientific community.
Let us briefly discuss what the Special Theory of Relativity is all about. It has basically two postulates.
First postulate:
It is known as the principle of relativity. The first postulate asserts that the fundamental laws of physics are the same for observers moving at constant speed relative to each other. It means that whether you are inside a ship that moves with a constant speed of 50 miles per hour, or you are inside a spaceship that moves at a constant of speed of 20 thousand miles per hour, the laws of physics are the same.
Second postulate:
Known as the light postulate, it says that light travels with constant velocity, and it is independent of the state of motion of the emitting body.
Startling conclusions:
The consequence of the second postulate is startling. It implies that time and space are NOT absolute. A serious correction is needed in Newtonian physics. For Newton, space and time are absolute. They are universal, and they exist regardless of matter; they are like a fixed backdrop. However, for Einstein it is spacetime, and it is an integral part of matter. Spacetime does not exist in the absence of matter.
You can read a more detailed discussion on special relativity here.
General Theory of Relativity
We must note that the Special Theory of Relativity is a framework that deals with the special case of referential frames moving in a straight line with constant speed.
Whereas the general theory of relativity deals with the case where acceleration is involved. It is also known as the theory of gravity. It answers questions such as: what is gravity? And how does it arise?
According to the general theory of relativity, the curvature of the fabric of spacetime manifests as gravity. It is a great insight! Only a genius like Einstein could get this insight.
Obviously, the general theory of relativity was packaged in serious mathematics. It took more than 10 years for Einstein to publish the general theory of relativity.
More on this topic to follow in a separate post.
Missed Opportunities
Can you believe that even the great genius Einstein could miss a few things? The point of this discussion is to emphasize how true a scientist he was.
1. Expanding universe and the Big Bang:
Einstein believed in the steady state of the universe. But his equation was predicting an expanding universe. So, he fudged his equation to suit the steady state. Later, when Edwin Hubble presented evidences for the expanding universe, Einstein not only changed his stand and fixed his equation but also described the mistake as a “blunder”. What a true scientist he was!
However, the recent discovery of the accelerating expansion of the universe, due to the dark energy, is making physicists think that the fudge factor is right after all.
He could have also predicted the Big Bang event as a follow up of the prediction of an expanding universe. He missed a wonderful opportunity.
2. Blackholes:
Though, one of the solutions to his equation resulted in infinite curvature of the spacetime, predicting a blackhole, he thought that it was not possible in reality, and nature somehow took care of averting this extreme condition. But now we know that blackholes exist and are real as his equation predicted.
3. Quantum Mechanics:
Even though he was one of the pioneers of quantum mechanics, he could not reconcile with the probabilistic nature (and the weird results) of the quantum world. He described it as ‘spooky’.
In one of the discussions on quantum mechanics, he commented:
“God does not play dice.”
“Moon remains the same regardless we look at it or not.”
Einstein strongly believed that quantum mechanics was not a complete theory.
Emigration to USA
In the early 1930s, when the political environment in Germany turned anti-Semitic, and as it became increasingly difficult for scientists like Einstein, he left Germany and emigrated to USA in 1933. In the USA, he joined the newly founded Institute for Advanced study at Princeton, NJ. Albert Einstein lived in Princeton until his death in 1955.