Physical Cosmology, Part I, Lead: Eberhard Möbius

2/4/2002

Summary by Jared Troutman:

Introduction to Physical Cosmology

Before the topic of the day, Physical Cosmology was introduced, a concerned discussion about the nature of "why" and "how" questions began. The initiating comment was that Science is not concerned with "Why" questions.

How is how different than why? Why is how different than why? By changing the How to Why on the very question of the difference one can Feel the difference. The first question, How is how different than why, yearns an appeal to the basic "mechanics" between how and why. The second question, Why is how different than why, asks for an explanatory answer deeper than the nuts and bolt distinction between how and why. It is the question of why that often times eludes us. Why are we here? To ask How did we get here is different than Why are we here? And to recognize the equal importance of each question and to truly ponder them is to begin an endeavor to human and cosmological studies.

The dialogue on how and why was put on hold with final comments on the "crudity" of language and the difficulty of having a dialogue when we are too caught up in properly defining each and every term. We turned to the topic of the day Physical Cosmology.

Cosmology is a theory of the universe's beginning and evolution to the present day. The Physical Cosmology is the scientific explanation to how did we get here. There are many different creation myths that explain how the universe began. Prof. Moebius showed the group overheads of the Judeo-Christian myth, The Cosmic Egg myth, Sedi and Melo from Indian mythology, and Death the Creator from Guinea.

Scientists have their own myth concerning the creation of the universe. A scientist wonders if we can stick our head out of the universe, as explained by a cartoon of a scientist pulling back the curtain of the universe to see the "clockwork" running the whole universe. We stumble in the paradox that it is impossible for us to objectively stick our head out of the universe. We are part of the universe. To look outside of ourselves is to have a viewpoint from no where, impossible. We can't look outside of our own investigation. In M.C. Escher's "The Gallery" a man looking at a painting in a gallery is actually part of the painting itself, making us see that we are looking out on a world intimately connected to our existence.

Prof. Moebius presented to the group his "pocket solar system." He asked how far away Alpha Centauri was in terms of the scale we were using. To illustrate the scale, Jupiter is the size of a marble; Earth the size of a pinhead, the rings of Saturn the diameter of a quarter. The guess was Kittery Maine. According to this pocket universe the closest star to Earth, other than the Sun, is in San Francisco.

Despite the vastness of the universe and the difficulty we have in understanding its size, the technology of modern equipment has helped scientists determine that the universe is 15 billion years young and finite. If the universe were infinite, then when we look at the night sky, the light of the infinite stars in the universe would blind us. Olber's paradox, illustrated by the layering of pine trees like looking at a forest, taught scientists that the universe is indeed limited and finite. The night sky would be a blanket of light, just like the blanket of green we see by looking at a forest from a distance, but we don't see a blanket of light. Thus the universe must be finite. We have no idea what potentially infinite number of galaxies might lie beyond the 15 billion light years that we can observe. So even with our highly intensified senses there is a limit, and what is beyond 15 billion light years is left as a mystery to us.

The Big Bang theory, at the center of the physical cosmology, is supported by Edwin Hubble's finding that the universe is expanding by observing the Red Shift. Scientists observe spectral lines to see how the wavelengths of light have expanded. Like raisins in a rising bread, all the galaxies are expanding from each other, as the "bread rises." This indicates that the universe could of started from a central "clump" that exploded, which eventually led to the organization of the universe in galaxies that are still traveling away from each other.

We left off here to pick up in two weeks with more of the Physical Cosmological myth that science has proposed.

February 20, 2002