The Economist has an excellent article addressing one of the central questions of modern cosmology: “What if the dark energy and dark matter essential to modern explanations of the universe don’t really exist?” The article makes a point that I have often thought about: are we so blinded by our assumed superior technologies that we may overlook possible misconceptions about “reality?” Looking back at some widely-held scientific theories of the past that have been proven wrong, it’s easy to see in retrospect which assumptions proved to be their downfall. However, what we now see as ill-conceived ideas were for the most part based upon the best possible technologies and experimental procedures at the time. What’s to say that we aren’t making the same types of mistakes now based on errant assumptions, or just a lack of technology to prove otherwise? There is a great passage to this effect in the article:
It was beautiful, complex and wrong. In 150 A.D., Ptolemy of Alexandria published his theory of epicycles—the idea that the moon, the sun and the planets moved in circles which were moving in circles which were moving in circles around the Earth. This theory explained the motion of celestial objects to an astonishing degree of precision. It was, however, what computer programmers call a kludge: a dirty, inelegant solution. Some 1,500 years later, Johannes Kepler, a German astronomer, replaced the whole complex edifice with three simple laws.
Some people think modern astronomy is based on a kludge similar to Ptolemy’s. At the moment, the received wisdom is that the obvious stuff in the universe—stars, planets, gas clouds and so on—is actually only 4% of its total content. About another quarter is so-called cold, dark matter, which is made of different particles from the familiar sort of matter, and can interact with the latter only via gravity. The remaining 70% is even stranger. It is known as dark energy, and acts to push the universe apart. However, the existence of cold, dark matter and dark energy has to be inferred from their effects on the visible, familiar stuff. If something else is actually causing those effects, the whole theoretical edifice would come crashing down.
The article goes on to explain some scientists’ doubts about this “status quo” theory of dark matter, surmising that the observations and measurements that the theory is based on could be misleading. I don’t know nearly enough about this topic to be sure either way, but I’ve been fascinated with cosmology ever since (and probably before) I took courses in Archaeoastronomy and The History of Science in college, and I’m glad to see that someone is questioning a somewhat kludged theory rather than blindly accepting it. Albert Einstein said, “Physics should be made as simple as possible, but not simpler.” On the other hand, one of the Slashdot contributors recalled a humorous, but quite appropriate quote from The Hitchhikers’s Guide To The Galaxy that could just as easily be true: “There is a theory which states that if anyone discovers just exactly what the universe is for and why we are here, that it will instantly disappear and be replaced by something even more bizarre and inexplicable.”
