Sunday, January 5, 2014

Our Friend the Spherical Electron

Something to think about while lying in bed.  How does an object with no size have mass, electrical charge, and have a property called spin?  The best theory that describes this particle and how it interacts with light says this particle has no size.  That's right a mathematical point, nada, zip,zero no size at all!  Whenever one calculates with this theory a property of this particle and compares this calculated result with the experimentally determine result for this property both theory and experiment agree!!  So this particle has no size yet it has mass and electric charge.  What is this particle?  Our friend the electron.  You know that thing that kind of makes all electrical signals work, what chemistry is all about.  Yeah that thing.  What all of the modern marvels you love (like the screen you are looking at right now) rely on, yep electrons.

Now because electrons are so small we cant't think of them in terms of balls roaming around in space.  Electrons exist in a size realm where our everyday notions of objects are different.  Its difficult to come up with words to describe objects in the quantum world since our language has been built up for centuries describing the would around us and that is very different than the quantum world.  At best think of an electron as a  spherical fuzzy object like a haze or a cloud. What really is the radius of such an object?  This fuzzy electrically charged sphere has recently been shown to exhibit the properties of a sphere to remarkable levels.  This has been shown shown most recently in:


This experiment showed that the electron's shape deviates from that of a sphere by the following amount.  Imagine the electron to be the size of a sphere of earth size (the earth is not a sphere).  This experiment showed that the deviation of the electrons shape from that of a sphere, say one side of the sphere bigger than the other side to be 1/10,000 the size of a hair.  That's incredible!!  Think about what that is saying.  Take a sphere the size of the earth.  Put a hair on that sphere.  It no longer has the shape of a sphere. We would say that it is not the shape of a sphere since one side is bigger than the other by the thickness of the hair. These guys have shown that the spherical shape of an electron is measured better than 1/10,000 that of the size of a hair we added to the earth size electron!!.

Oh the experimental limit on the size of an electron is given here:

http://gabrielse.physics.harvard.edu/gabrielse/overviews/ElectronSubstructure/ElectronSubstructure.html

But, just because the theory says they have no size doesn't mean they can't have  size, it just might be smaller than any attempt to measure it has discovered.  Experimentally we know that electron's are smaller than 1/1000 th the size of a proton.  Protons do have a size since they are made of constituent particles known as quarks.  Amazing!!!  Humans can do incredible things!

No comments:

Post a Comment