The psychology of stargazers.

We have always perceived our position within the heavens, as being special, we move slowly and grudgingly to accept new views and theories that demote our position and importance within the universe, even when faced with overwhelming evidence.  With each new theory that gains acceptance you can guarantee that a small faction of academics will cling to the old view, and fight its corner as if their reputation depended on it.  Our natural reaction even in these enlightened times is to believe that the universe exists just for us, that we have a unique position. We need a purpose, after all, if we did not exist what would be the point of the universe, it must exist simply for us to understand, it is our universe. I believe that this trait, this psychology, is one of our greatest strengths, it what drives us to make new discoveries. However it also can limit our views, we fail to see the wood for the trees, or in this, case we cannot see the universe for the stars.

Five hundred years ago our position within the cosmos was safe, from the information available at the time it was perhaps the only logical conclusion.  Our knowledge of the night sky in those days came from the great thinkers of ancient Greece,  Eratosthenes had experimentally determined that the Earth was a sphere, no mean achievement considering the limited equipment available to him. Hipparchus studied “wandering stars” or planets, stars that did not conform to the rest of the night sky, he assumed that the planets were in orbit, as were the stars, the Moon, and Sun, around the central spherical Earth.

Ptolemy, in the second century AD, studied the movement of the planets very closely, he found that they did not behave in the way they should, the planets would occasionally move backwards in their orbit.  How was this possible if the Earth was the hub of the universe, to force the accepted model to work, Ptolemy devised epicycles, loops with in the orbits of planets that satisfied the observed movements. So for the time being our privileged position was still secure.

In retrospect we may wonder why Ptolemy did not simply take his new observations and try every imaginable model of the solar system, until he found one that fit.  This is a typical example of the way our logic is corrupted by our psychology, we mess with our data, or disregard it, if it is in conflict with our accepted view, we fear championing a new idea, even if the current one does not work.  Our approach should be to consider all new information and force ourselves to come up with an alternative theory, we must then try to tear it apart, to validate every aspect of it. We may find it is just as difficult to disprove a theory, than it is to prove one.  Ptolemy may have been one of the first scientists to twist his theory to fit his observations and the accepted view, but he certainly was not the last. Einstein made a similar mistake of which it is said he later had deep regrets.  It would seem to be in our nature to conform, we would rather fine tune a model than rip it up and start again, after all we may upset our piers, we may go out on a limb.  This psychology did not stop Copernicus proposing that Ptolemy’s epicycles could be eliminated, if the Earth and planets were in orbit around the Sun.  Copernicus came to this conclusion without any new technology, he simply took the facts and made a model that would fit, then he checked it again and again. He was either a very confident person or perhaps he was far enough from Rome, that he had the nerve to publish his findings, or did Copernicus simply understand that every new idea should be dissected and debated until either accepted or rejected, and that no shame should fall on the brave sole who stands up and says “I have an idea”.

Johannes Kepler and Tycho Braye fine-tuned the Copernican model using elliptical orbits but the Ptolemey model was still the accepted view. It was not until three hundred and fifty years ago, that Galileo used a telescope to look at the wondering stars, in looking at Jupiter and its moons he saw a Copernican model in miniature. Even though Galileo had been loyal to the Ptolemey model and had even taught the theory, he was brave enough to publish his findings and support the Copernicus theory, his employers were not pleased.

The work of Newton was the final nail in the coffin for Earth centred theories, he tied it all together, but it had taken Copernicus, Kepler, Galileo, Newton, and a hundred and fifty years to put the Sun at the centre of our elliptical orbit.  Perhaps it required these people of such great intellect to chip away at the deep-rooted views of the time, or maybe the idea of our species being of great importance to the cosmos, is just too appealing.

Once we had slipped from our central position, we were free to probe deeper into space, with our rapidly improving equipment we could look deep into Newton’s infinite universe. Thomas Wright, Charles Messier and Herscher established that our solar system is part of a greater group of stars, christened a galaxy, and that beyond our galaxy were others.  The work of Fraunhofer, Doppler and Hubble gave us an expanding universe, again we were slow to accept this new view, preferring the psychologically safe steady state universe. The irony of which is highlighted by the fact that Einstein invented his cosmological constant because his great theory predicted an expanding universe, he corrupted perhaps his greatest work to fit the accepted view of a steady state universe. His work was of course great enough for the constant to seen for what it was and removed once the expanding universe theory came to the fore, but according to biographers Einstein had deep regrets about being influenced by current thinking rather than going where his calculation led.

In five hundred years our position in the cosmos had gone from, king of all we survey, to small planet going around a small star at the edge of ordinary galaxy, in a group of galaxies, surrounded by millions of other galaxies, in an expanding universe. However our “gut”, still tells us that we cannot be that insignificant, we need a position or rank no matter how humble. If we are that insignificant then what is the point of our existence, does this huge and wondrous universe exist simply to test us, to stretch our reasoning powers, perhaps the size of the universe is actually a compliment to our intelligence and ability to understand. Or should we try to understand the universe objectively and disregard our selves and the problems we have with our diminishing importance.

The amazing irony of the big bang theory is that it was proposed by Lemaitre, who as a Catholic priest brought the Church back into cosmology. He interpreted Einstein’s theory to give a singularity that not only gave rise to our universe but also gave the church an inexplicable event, a potential point of divine intervention, things had come full circle from Ptolemy.  With our current thinking it is not just difficult to fully explain the Big Bang, it is perhaps impossible, but at least we are back to our comfort zone of creation, a creation undoubtedly intended for us alone.  It gives us a beginning, and the bonus of an unexplainable one, we are currently living in the middle of our story, now all we need is an end. 

Could the expansion of the universe continue forever? Of course it could, but that gives us an uncomfortable feeling, there would be no cycle, no rebirth, and the whole of nature is a series of cycles, it is what we expect. It is impossible for us to accept a one off big bang, a shower of bright lights in the sky, followed by the spent firework of a dead universe, we need a cycle. The big crunch sits easily with us, we no longer need to think of the big issues, we can bury our heads in the mathematics of gravity, we have our cycle. Big bang, expanding universe, gravity slows then stops the expansion, the universe falls back in on itself, giving us the big crunch, it sounds right. Except we cannot get it to work, the numbers simply don’t add up, there is not enough matter to give us the closed universe cycle we desire. Inventing dark matter has helped, it surely must exist, but not in the massive quantities required to slow the expansion of the universe, let alone reverse it. So rather than rethink the theory, we rethink the dark matter problem, we cannot face the prospect of an open universe, the spent firework image is simply pointless and ugly.