Not that many people know that a second Scientific Revolution happened in the 1920’s.  It was during this time that scientists like Einstein, Heisenberg, Schrödinger, and others had finally started putting together a deeper understanding of our world on a sub-atomic level.  A lot of important discoveries had been made up until that point, but in 1925, a new scientific field of study had emerged out of equations and experiments: Quantum Physics.

It sure sounds cool!  “Quantum Physics”.  Ooh yeah :-D.  But is this just another inaccessible scientific body of knowledge - only privy to those who understand the jargon of the University professors?  No!  Quantum Physics might sound a little intimidating, but it’s actually pretty easy to gain a basic understanding of what happened in the 1920’s, and how it impacts our understanding of reality.

Prior to this Revolution, humanity had a Newtonian outlook on reality.  This world-view was invented in the 1600’s, by Sir Isaac Newton, and stated that things are basically mechanical.  When you push something, you are putting a force on it.  When you drop something, it falls because the Earth has a gravitational field… pulling objects towards the center.  If you throw something up in the air, it will curve in a parabolic arc - eventually falling back to the ground.  Things accelerate, and move, and everything behaves according to what math tells us.  There is a formula for how everything works.  Reality is just one big machine.

When we started to zoom in on things, we expected to see this same mechanical world.  We zoomed into the cell, and saw miniature machines.  Then zoomed in more, to the molecule, and saw little gears.  Then even more: in 1913, Niels Bohr came up with his famous depiction of the atom:

 

Marbles!  Brilliant!  Looks like Newton was right - everything is just mechanical.  Everything is just a bunch of complicated machines, working in amazing ways - but still just machines.

It’s important to understand this mindset.  This is the mindset that a lot of people have about reality today.  If you ask someone to draw an atom, they will likely draw the 1913 version above.  The only problem is that it isn’t 1913.  It’s 2008.

The funny thing is… if you zoom in a little bit more… everything seems to just fall apart.  The normal rules about reality - the normal common-sense-Netwonian rules - don’t work.  Not only do they fail, but they fail magnificantly.

This is what an atom looks like in 2008:

What, no marbles?  My goodness… that almost looks as though it’s some sort ball of energy…

So what happened?  What changed our understanding in 1925, that made us re-think everything?

The Uncertainty Principle

Scientists saw those marbles, and thought: “Well gee, if I know exactly where the marble is, and what direction it’s moving in, then I can predict exactly how the atom is going to behave.”

And when they tried to find where the marble was, they couldn’t figure out what direction it was moving in. And when they could figure out the direction, they suddenly couldn’t figure out where it was!  No matter how hard they tried, they couldn’t figure out both pieces of information (location + direction) at the same time.

So what? It sounds like we just need better equipment, right? The Uncertainty Principle changed that - it stated that it’s physically impossible to know both the location and direction at the same time. It’s a law etched into our reality.

Why was this a fantastic deal in the 1920’s? Because the mechanical world that scientists have grown and loved over the previous 300 years was shattered. Things were no longer machines. There was divine Uncertainty, hard-coded into reality itself. And Uncertainty is scary.

This entry was posted on Tuesday, October 14th, 2008 at 10:34 pm and is filed under Science. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.