Dark Energy Epicycles


There is a world hidden from sight.  A world that we cannot touch, see or hear.  It is hidden behind every point of space and every moment of our lives; a dark world that surrounds us.  Or so most scientists believe.

galaxy spin speed

Graphic showing how the measured speeds of stars as they get further from the center of their galaxies does not decrease to match calculations.

Why do scientists believe in this hidden world?  Because galaxies should simply not exist based on our understanding of gravity and the laws of physics.  These massive collections of stars spin so quickly that they should unravel and throw their contents into the darkness of space.  But they don’t.  There is something holding them together.

That invisible something was coined “Dark Matter”, first by Jan Oort in 1932 and later with better evidence in 1960 by Vera Rubin.  These theories propose that dark matter and dark energy actually account for 96% of the universe compared the mere 4% that makes up the world we know.  Could this actually be true?

dark matter


The astronomers of 16th Century Europe faced a very similar problem.  The all powerful church and its scientists were convinced that all the planets and Sun revolved around the earth in perfect circles.  Only fitting that a perfect God should create a perfect heaven rotating around the blessed planet earth.


However, the heavens did not agree with this circular perfection.  Staring through their telescopes, these astronomers noticed that the planets and sun moved in much stranger paths; slowing down and speeding up in strange intervals.   A most upsetting discovery to the devout but to rectify the discrepancy they came up with the theory of planetary epicycles.

These epicycles were patterns of circles revolving around other circles to explain the strange movement of the planets.  The complexity of these diagrams were staggering, working against their original intention of a beautifully simple cosmos.


Representation of a epicyclic solar system proposed by church astronomers.

The astronomers of this time were either to afraid of persecution or too biased from indoctrination to see that their current paradigm was the problem.  The universe was not made of perfect circles, and the earth was not the center of the solar system.  A revolution of thought was required in order to understand our solar system. 

The old paradigm had to die so that a new view of the heavens could be seen.  And so this revolution required revolutionaries that would push forward without fear into a counterintuitive world.  This was first done by Copernicus, proving that the sun was the center of the solar system, and then by Ptolomy and Newton, proving that Gravity caused elliptical movement of the planets.

These revolutionaries looked at the world without bias.  They pushed past fears of dismissal or persecution and simply searched for the truth.

It can be such a difficult thing to forget how the world ought to be and to instead see it as it is.

Perhaps, science has still not learned this lesson and the proposed theories of dark matter and dark energy are the proof.  It could be that instead of this dark world existing, the simpler answer is that our equations for the laws of gravity and motion are wrong.

Or more boldly…Einstein could be wrong.  Now that would be a revolution.


By | 2015-11-11T07:24:39-08:00 July 23rd, 2015|Astronomy, Featured, Philosophy, Physics, Science|Comments Off on Dark Energy Epicycles