Our friend Sol
July 2013 :
A very hearty welcome to everyone, especially newcomers to astronomy who feel intimidated by the expertise of the Rhode Island astronomy community. Herein is offered a monthly look at the Universe geared to beginners, as seen through the perspective and enthusiastic eyes of a beginner—me. Together, we’ll explore the awesomeness of the sky and try to understand many of the imponderables of the Universe. We’ll marvel together as we gaze into the same spaces our distant ancestors did, ask the same questions they did, and forge our place in the link between the past and future.
We’ll start our explorations not with the nighttime sky, often thought the realm of astronomy, but rather, daylight time. To be sure, distant stars and planets populate the daytime sky as they do nighttime, but for our own star, the Sun, go unviewable. We’ll come to appreciate the Sun, this beautiful orb of energy. And, we’ll acknowledge that mankind’s romance with her will be but a brief fling, for she will die in a mere five billion years; a drop in the bucket in cosmic time.
First a geography lesson. Rhode Islanders constantly hear our state referred to as a unit of measurement. Rhode Island natives learned in the hallways of elementary school from classmates speaking in hushed tones that 257 Rhode Islands’ fit into Texas or that 634 fit into Alaska.
I tell you this because, today, we are implored to think globally and act locally. Okay. Acting locally implies visiting Seagrave Observatory or any other local Observatory open for public viewing.
Thinking globally infers that one million Earths can fit into the Sun. The diameter of the Earth is almost 8,000 miles (12,750 kilometers). That of the Sun is 865,000 miles (1.39 million kilometers). That’s huge! Yet, the Sun is a baby compared to many of its other cousins. There are an estimated 1021 stars in our Universe. If you write that number out, it looks like this: 1,000,000,000,000,000,000,000. The largest of these approach a size about 800 times that of our Sun. These truly are the cosmic Alaska’s.
Don’t like summer heat waves? Consider this: the temperature at the core of our Sun is about 29 million ̊ F (16 million ̊ C.) Temperatures at the surface are a balmy 9,900 ̊ F (5,500 ̊ C.) Really? Earth bound fire fighters routinely enter burning infernos of 1,100 ̊ F (593 ̊ C) to save life and property. Disgruntled restaurant customers burn their palettes on hot beverages a lot cooler than that, and routinely sue the restaurant!
And, then there are sunspots to consider. Sunspots are funny things. Sunspots on the photosphere (surface) of the Sun are large. An average sized sunspot is about the same size as the Earth. There we go again, thinking globally. They are cooler than the adjacent surface of the Sun. They travel slowly across the Sun in groups. They are on an 11 year cycle of heightened activity. Also, they are magnetized. And, just for good measure, they change their polarity every 11 years. What was north becomes south and vice versa. When you think about it, sunspots are really awesome.
Still, I have a gripe with sunspots. They disrupt communications on earth and do other dastardly deeds. For instance, 1970’s CB radios were a great thing while travelling on the highway. Huge convoys of cars and trucks would form, their drivers all talking to each other. You could acquire a funny handle. Everybody and his brother rushed out to get a CB radio. Sadly though, their popularity diminished over time. Why? Among other reasons, sunspot activity interfered with the transmission of their radio waves over long distances. As with the dinosaurs, who got dumped on by an asteroid (a subject for a future column), the Universe had its say. Many a grown man cried, but hey, we still have the song: Convoy, http://www.youtube.com/watch?v=FcaeYmT4wsg.
In closing, I hope you have a keener appreciation of the nurturer of all life, our Sun. Next month, we’ll continue our explorations. See you then!
Mark Sweberg
Your comments on this column are welcome. E-mail me at mark.sweberg@gmail.com
