Quantum Physics for Dummies

The Greeks named “the atom” as that which cannot be divided further.  It is the smallest particle.  Democritus, Leucippus, and Epicurius proposed that dividing matter into ever smaller particles leads to particles that cannot be divided further, “the atom.”  The ancient Greek word, atom, means uncuttable.  But they were wrong! Ernest Rutherford came up with the idea of what an atom is made of and is what is now considered the Rutherford atomic model.  It is a dense central nucleus of protons and neutrons surrounded by a cloud of electrons that orbit around the nucleus. A lot of empty space exists beween the electron cloud and the nucleus. If you place a football at the 50-yard line representing the nucleus, the electron cloud is at the goalposts with nothing in-between. Quantum tunneling is the phenomenon where particles can go right through solid barriers like ghosts go through walls. Could all that empty space allow that to happen? The knife to cut the atom turns out to be quite elaborate, the LHC (Large Hadron Collider). Near Geneva, in Switzerland, is the largest, most powerful particle accelerator ever built.  It is a circular tunnel, 100 meters underground, 27 km in circumference, that propels particles at near the speed of light in two beams going in opposite directions, and then the particles are made to smash into each other.  It turs out, atoms are divisible! These particles are pieces of the atom called Bosons, Hadrons, and Fermions.  To date, the count of these particles is 59.

All these particles have a variety of qualities, from electric charge, to spin, and mass. The Higgs Boson (also called “the God Particle”) is what gives everything mass, and is one of the more recent discoveries.

Newton (1642 -1726) was the go-to guy for astronomy, physics, and mathematics for hundreds of years.  Then came  the Quantum boys and girl – (Madam Skłodowska aka Curie) in the early 1900s. The founding father was Max Planck, but others contributed, like Niels Bohr, Werner Heisenberg, Paul Dirac, Wolfgang Pauli, and Erwin Schödinger. Einstein was not a fan of Quantum Mechanics but still influenced its direction with his special and general theory of relativity. The central ideas of Quantum Physics are that the very small world has different rules than the world of Isaac Newton which we can see.

The Copenhagen Interpretation

The great minds of Quantum Mechanics came together in Copenhagen and came up with a loose set of temporary compromises, still being debated today called the Copenhagen Interpretation, which concluded, among other things, that a state does not exist until it is observed. The act of observation forces the particle to choose what it will be.  This also concerned Einstein.  His famous retort was that the moon was still there even if he didn’t look at it.

Very small particles can be both a particle and a wave.  It can even be at many places all at once. Identifying where a particle exists is not certain until it decides where to land. Particles can become “entangled” with each other through one of four mechanisms. Once they are so entangled, whatever happens to one will influence what happens to the other instantaneously, even if that particle is on the other side of the universe. This idea really rankled Einstein. He called it “Spukhafte Fernwirkung” spooky activity at a distance. One cannot know both, where a particle is, and at the same time how fast it is going (Heisenberg’s Uncertainty Principle). A particle could be in several places at once.  And two opposite states can simultaneously exist until they are observed (Quantum superposition).

  The act of observation forces which state exists. Schrödinger’s dead cat thought experiment has a cat in a box that is both alive and dead until it is observed to be one or the other.

Max Karl Ernst Ludwig Planck was a German theoretical physicist who was advised not to study physics since everything had already been discovered, he was told. His response was that he didn’t want to discover anything new, just to understand what had been discovered. He was a Professor at the Berlin University. In the early 1900s, he formulated his Quantum theories. He took a year’s sabbatical from the University to travel around Europe to explain his theory.  Despite his brilliant scientific mind, he could not drive a car.  He had to hire a driver.  When he returned to Berlin to give his last lecture, he had a severe cold and could not talk.  He decided to cancel.  His driver talked Planck into letting him give his talk which he by now had heard hundreds of times. Plank agreed, and it went as planned until, during the question period, a wizened old physicist asked a question that the driver had no idea how to answer. As Planck was sitting in the audience, the driver cleverly turned the tables on the smart-aleck questioner. “I can’t believe such a basic question would be asked in this sophisticated group, and to prove it, I will let my chauffeur answer that!”

I just barely got through college physics 101.  To get my experiments to come out correctly, I fudged some data, which the professor figured out faster than entanglement could. “There is something fishy here!” he exclaimed. Quantum mechanics is vastly more complicated. The concepts are admittedly difficult to understand, and even Einstein didn’t either.  How a particle can be in two places at once, how the cat is both alive and dead, how information can travel, from one end of the universe to the other instantaneously, when the speed of light is the fastest anything can travel are concepts that just fly in the face of what we know. You may wonder why I even bother to try to understand.  The problem is that these impossible concepts are why we can watch TV, why our GPS takes us to the right address every time, why atomic clocks keep perfect time, how superfast computers work, how the salmon return to their birth stream, how Magnetic Resonance Imaging takes pictures of our brain, and why we should not detonate even one Hydrogen bomb any time soon.

This is just the beginning of what is in store for us.  The idea of time travel sounds impossible, but the fact that time and space are called space-time because it is made of the same fabric suggests a possibility. Gravity slows down time, the stronger it is the more it slows time and even stops it inside a black hole.  Theoretically, we could just walk upstream  the time continuum to get to our past or downstream to get “Back to the Future” (?) If space can get a wrinkle in it, and a wormhole can drill through that carpet of space, we could travel to the end of the universe in no time at all(?) If we are all made of quanta, then a very sophisticated quantum computer could disassemble all the parts of our atoms, transmit their structure to entangled computers instantaneously to one of Alpha Centauri exoplanets and reassemble us there (?) Sounds crazy!