The Big Questions Part 2

11/13/05 – 11/19/05

By C. Zaitz

Last week we learned three of the “Seven Things Everyone Should Know About the Universe.” Let’s review those and finish the list this week.
We learned:
1. The universe and all of space is expanding from a Big Bang beginning. 2. The microwave echo of the Big Bang allows us to see back to almost the beginning. 3. In the very beginning, the universe was a hot soup of quarks and elementary particles. Let’s talk about what we see now.
4. Stars account for less than 1% of the stuff in the universe today. That means that stars, and the galaxies they form, are just a tiny bit of the whole universe. That also means that 99 percent of the universe is dark and we don’t really know what it is. It doesn’t seem to interact much with the stuff we do know of, so that makes it a little harder to figure out what it is. Fun!
5. We are made of the star stuff, but the universe is not. We know that most of the “stuff” in the universe is dark matter and dark energy, but we are not made of that; we are made of the stuff we find in stars like calcium and oxygen. Dark matter isn’t on the periodic table of elements.
6. The expansion of the universe is speeding up, not slowing down. This is one of the discoveries that has contributed to the research into dark energy, since the expansion was discovered observationally before a theory was in place to explain it. Dark energy is thought of as a large, negative pressure in the universe that is somehow overcoming gravity and speeding up the expansion of the universe.
7. All of the deuterium and most of the helium in the universe was made when the universe was just seconds old, as well as the hydrogen of which most of the visible universe is made. This is important because it is a condition of the Big Bang hypothesis, which says that these light elements were created in the first moments of the universe, and everything else, including our diamond rings and stainless steel wheel rims, were created from the explosions of giant stars long afterwards. We now know that the young universe was devoid of these heavier elements and the only place where such things as gold and cesium could be fused into being is during the explosion of a huge and dying star. So, my friends, we are all recycled from such a star’s death. And that makes returning soda cans seem like child’s play.

If you still are left wondering, come to the Ensign Planetarium on November 16th, 7pm for Cool Cosmology. Meanwhile, Mars shines brightly in the southeastern sky at sunset and in the morning in the western sky. Venus is low in the southwest right after twilight.

Until next week, my friends, enjoy the view!