The Science of the Universe
Lead: Eberhard Möbius

4/5/2010

Summary by Kristyn Lattanzi

The Anthropic Principle

The science of the universe is a unique and difficult concept in scientific study. There are many planets stars and galaxies, but only one universe. Therefore, scientists can only perform independent tests on one and the same object. Professor Moebius’ presentation guides us through the ups and downs of the difficult task of studying and explaining our one great universe. Through the explanation of a series of different models of the universe and their respective discourses, we are shown the many ideas about our universe’s origin.
The first model of the universe is the big bang model. This ‘model,’ is really an idea of from whence our universe came and how it was created. There are three tests that support the big bang model; The Hubble Expansion test, background radiation test, and the study of the ratio of Helium to Hydrogen in our universe. The Hubble Expansion: i.e. the observation that distant galaxies recede from us in lockstep with their distance, supports the Big Bang model in that it proves that our universe is constantly expanding outward, an expansion believed to be caused by the presence of dark energy in our universe. The study of background radiation is another independent test done on or universe. This test examines the slow cooling dispersed material and radiation due to expansion. Because when our universe was formed it was so hot, atoms could not form and therefore it took time for the universe to reach a temperature fitting for such formation. Now that scientists can study this cooling relative to a larger time span, the test shows that most likely these particles have existed for billions of years and have been cooling ever since. Helium and Hydrogen make up the majority of the mass in our universe. These levels were impacted by the speed of expansion of the universe, and, therefore, without the big bang and its ensuing expansion, the chemical make-up of the universe would be vastly different.

From here professor Moebius began to discuss the problems with the big bang theory. Though the tests that have been done in support of this theory are often times difficult to argue, they are not, by nature, ultimately concrete and leave quite a bit of room for discourse. The first problem discussed is the problem of ‘flatness.’ This problem suggests that should the universe have been composed of more matter in the beginning that it would eventually collapse, and had there been less matter it would have been expanding much too fast, so that no galaxies or stars would have formed. Tests today suggest that the universe has the potential to continue expanding forever – while maintaining its flat geometry. A second problem with the big bang model is that we are limited by our ‘horizon.’ The final hole in the big bang model of the universe was not created with the presence of any anti-matter. How can there be any matter left in existence at all? Where did the once supposedly abundant anti-matter go? All of these questions are surrounded by ideas about the formation and dissipation of anti-matter, and though these questions in no way disprove the big band model, they are not answered or incorporated fully into the model.

In the wake of such seemingly tangible evidence, professor Moebius goes on to remind us that in fact there are very few things about the universe of which we can be sure. There exists in the universe this set of determinable constants which theories can neither predict nor explain, yet the values of these constants appear to be fine tuned for our existence in this universe. Should any one of these constants be altered a surprisingly small degree, and our universe would no longer be suitable for life. As our existence in this universe is our easiest and arguably most profound observation in the universe, we are forced to recognize and consider the importance of these constants in our universe. In other words what we know in absolute certainty is little more than that we are here and we are asking these questions. Beyond that we are once again reminded of our significant boundary condition, and the fact that it is impossible for us to study our universe without being an active part of it.

This observation carries the discussion into the realm of an idea best summarized by a certain goldilocks allegory. Should the universe have been just “a little too hot,” or “a little too cold,” rather than “just right,” we would not be here to discuss it. According to Leibniz, “we live in the most perfect of all worlds.” Though this observation could and would be countered by many people if applied to anything other than the physical make up of our universe, it is a relatively apt statement otherwise. The anthropic principle is a summation of several ideas asserting that the universe must be compatible with life, ultimately because life exists and therefore it is a cyclical argument. Essentially our universe creates complex structures which are used by nature to produce life. There are two versions of the anthropic principle one deemed strong and the other weak. The weaker of the two is an argument that basically states, we’re here therefore the universe contains elements necessary for the presence of life. The stronger of the two suggests that conditions in the universe exist as they do with the presupposition of the eventually existence of life.

The conclusion of class discussion found itself in the daunting realm of the ethereal and the argument for the potential existence of a thinking and active higher power. All potential denominations aside, with the level of exactness to which our universe has been formed to fit our existence, it can be argued that the existence of a god actually simplifies the issue. The idea of divine design would fill in the variables as far as how our universe managed to be so ‘just right.’ Ultimately the Anthropic principle could be satisfied by design and we may never really know the hows and whys of its seemingly miraculous existence.