The Fisher Files

I was reading Resnick last night about some of the either experiments (MM, of course, but also the Fitzeau experiement).  I was struck by how primative the thinking was at the time.  At the time of MM (1881), physicists could not image any other way for a wave to propagate than through some medium that gets disturbed, like the way sound compresses air or ripples in water.  It took Einstein’s explanation of the photo-electric effect as light quanta (photons) moving through the vacuum to really solidify the idea that electromagnetic radiation moved through the vacuum like particles.

These days, physicists and astronomers are grapping with a similar sort of problem: dark energy.  When we observe a distant superpnova explode, it seems to move faster then cosmologists expect from the amount of matter in the universe.  The best guess right now is that the universe is filled by dark energy which is a very strange substance.  If you take a normal gas on Earth, the pressure is positive (pushing out) and increases with density, while for dark energy, the pressure is negative (pulls in) and decreases (gets more negative) with density.  There is about 20 times as much dark energy as there is energy in normal matter (neutrons, protons, etc.)  Not much else is known about dark energy; dark energy is very hard to study because its effects as so small.  Astronomers have to look at very large things (clusters and super clusters of galaxies) to see effects of dark energy.

Thinking about the ether an dark energy makes me wonder if we are just being stupid (i.e. dull, lacking keenness of mind) in our thinking about dark energy like the physicists of 1880 thinking about the ether.  I expect there is some wonderful new picture that will emerge and in twenty, fifty or a hundred years, our descendents will wonder why we couldn’t see something so obvious.