Schrödinger's Unfortunate Cat

Why?

OK, so we're all huddled around the TV, inexplicably excited by the prospect of watching a re-run of the 'Big Bang Theory' and next thing you know the entire house has been launched into a heated discussion about Schrödinger's cat and what the experiment is all about.

And while the show did mention the Copenhagen interpretation (hat's off to Sheldon on that one) it then proceeded to throw out the limitations detailed in that very document and apply quantum superposition to Penny and Leonard, who, since they are ever-so-slightly larger than a sub-atomic particle throw the whole thing out the window and essentially, use the cat experiment to make the exact opposite point to the one our poor unfortunate Schrödinger was attempting to make.

Schrödinger, Forever Upstaged By His Damned Fictional Cat

We tried, and failed, to cover this over dinner but homework and baby baths wait for no physicist so this was left to be discussed in installments as time (and Bruins games) allowed. The one thing that became apparent during that first talk was that this will require one of two things of participants:

• Blind faith in the proven theory that sub-atomic particles can exhibit superposition; they can be in 2 places at once. This one was a problem for us; blind faith is a rare thing inside these walls.

• Or, a deeper dive in to quantum superposition. Which we did, and documented here, for the sanity of readers, this particular writer, and scroll-bars the world over I kept this a separate post.

So, assuming we're all ready to accept that sub-atom particles can be in two places at once, here we go....

Erwin Rudolf Josef Alexander Schrödinger, born in Vienna in 1887. He is, by any standard, wicked smart. He studies and works his way into academia, goes off to war, comes back and begins to make a number of significant contributions to several fields of physics including electromagnetism, color theory, thermodynamics, cosmology... Like I said, wicked smart. But he was only getting started.

In 1925 he works on what would become the Schrödinger equation. It is a partial differential equation that describes how the quantum state of some physical systems varies over time. Essentially, it describes the position of an electron in a hydrogen-like atom at a specific time. This was, and still is today, a big deal. He publishes this in 1926, and would go on to win the Noble Prize with Dirac for this contribution. Again, big deal.

Meanwhile, two other wicked smart physicists are working on a project attempting to review where we are with the business of quantum mechanics. Bohr & Heisenberg (and a number of other scientists) publish the Copenhagen Interpretation in 1927. This document mentions Schrödinger's equation that had been published 1 year earlier and takes it one step further. While Schrödinger had written the equation to describe a very small, very specific system, the Copenhagen interpretation applied his equation to larger systems - like planets, and galaxies. And in that instant 2 things happened.

1. People started to think that well, if an electron can occupy all possible positions at once, and if the same thing is true about planets and galaxies and big stuff well then....hello....the notion of parallel universes is born. An infinite number of universes where 1 thing is different, or everything is different, or even we (humans) can explore every possible outcome. Now don't get me wrong. This is a very cool idea, and one that I'm a big fan of in the context of sci-fi but is a long way to go with the Schrodinger equation.

2. Schrodinger himself (in my head at least) thinks "Cool, but wait, that's not what I said". He simmers for a bit and talks it over with his buddy Einstein and then comes up with what he thinks is a good way of explaining to the average non-genius that just because his equation works on tiny things like atoms, it doesn't really apply to big things like galaxies. Queue the cat.

Schrödinger's Cat Experiment

The experiment involves a cat, a radioactive isotope, a Geiger-Muller tube, a large hammer and a closed box. The premise is;

The radioactive isotope had 2 possible states. It can emit radiation, or it can not. If it does emit radiation, the Geiger-Muller tube detects it, triggers the hammer and squishes the cat. If it does not emit radiation the cat takes the hammer, uses it to flatten the Geiger-Muller tube and waits to unleash the claws of hell on the unfortunate soul who opens the box.

If superposition can be applied to large scale objects (in this case the isotope) it could both release radiation and not release radiation at the same time. So by extension, the cat would be both alive and dead at the same time. Schrödinger was relying on the average person realizing that a cat can not be both alive and dead at the same time and thus realizing that, of course, superposition (and his own equation) could not be applied to things bigger than sub-atomic particles. Good plan, right?

Not so much. Instead people saw this experiment as an extension of the Heisenberg uncertainty principle, who was one of the scientists behind the Copenhagen Interpretation in the first place. Essentially taking it to mean that if superposition can be applied then the cat is both dead and alive until someone checks the box, an that observation pulls the cat into 1 of two possible realities. Which is a nice idea, and it seems to have stuck, but it's not what Schrödinger was saying. Ironically, it's not what Heisenberg was trying to say either, since he was talking about the accuracy of a mathematical function, not any kind of physical system, let alone one involving cats.

Schrödinger would later give the following quote regarding Quantum Mechanics and the cat experiment:

"I don't like it, and I'm sorry I ever had anything to do with it."

Read more at http://www.brainyquote.com/quotes/quotes/e/erwinschro304793.html#uERMpdYcpiUvee8S.99

On Schrödinger

He was a fascinating man and well worth a trip to Wikipedia. These are some of my favorite pieces of useless information on him, none of which earned him the level of notoriety as has been achieved by his fictional cat.

• In 1927, he succeeded Max Planck at the Friedrich Wilhelm University in Berlin but decided to leave Germany 7 years later because he did not support Nazis' anti-semitism.

• His public opposition to Hitler would cause him problems holding down jobs later in his career. He was dismissed from the University of Graz for being politically unreliable.

• In an effort to keep that job in Graz he recanted some of his earlier statements about antisemitism but it didn't not save his job. He later said that he regretted recanting those statements and publicly apologized to Einstein for faltering.

• Éamon de Valera invited him to Ireland to help establish an Institute for Advanced Studies in Dublin. He lived in Clontarf, and if anything could make a man consider the viability of parallel universes that should have done it.

• He was the Director of the School for Theoretical Physics in Dublin for 17 years and he became a naturalized Irish citizen in 1948.

• He lived with both his wife and his mistress, which proved to be another stumbling block to being awarded those prestigious academic jobs.

• He did have a bit of a reputation for having romantic encounters with his students and fathered at least 2 children with Irish women during his tenure in Dublin.

• He did at one point have a cat, named Milton. It is not known if he would have volunteered Milton for his experiment.

• He has a crater named after him on the dark side of the moon.

• His 126th birthday was celebrated with a google-doodle featuring, you guessed it....