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Q & A: cosmic questions

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Most recent answer: 10/22/2007
Q:
Let me start by saying that I am sorry if I am going to ask a question that has already been answered. The whole concept of science is just something that I have not been able to grasp. I just seem to question everything. I would like to ask a series of question; 1. Why do the planets revolve around the sun? And how is this proven? I mean how do we actually know that the planets revolve around the sun? 2. If humans have evolved and adjusted to living on Earth is it possoble for other life forms to evolve and adjust to living in their environment(without water, warmth, light, ect.)? 3. In one explination that you had made in a question "Why does the universe exist," a statment was made that "In the Very Beginning there was a void -- a curious form of vacuum -- a nothingness containing no space, no time, no matter, no light, no sound." How do we know that this is true? I know that they may seem like dumb questions. However Iím the type of person who doesnít believe it unless I see it and raise a question about everything. Thank you for your time.
- Kimberly (age 18)
Tobyhanna, PA
A:
Kimberly- The only thing dumb about those questions is the hope that we will provide good answers. I'll do my best, but they're tough.
1. I often give a course in which we spend weeks working on this question. Long story very short: let's just say that we have a nice coherent mathematical description of how things move (Newton's laws) which works very well to describe the solar system and all sorts of particular things on earth (balls rolling down hills, etc.), but only if we say that the planets go around the Sun. At our most precise current level (General Relativity) it turns out we are forced to use more complicated equations, and within those we can choose different descriptions, and we don't have to have the Sun be the nearly stationary thing. I'll answer this more if you want, but meanwhile on to the other Q's.
2. We don't know very much about what conditions are needed to allow life to evolve. My personal guess is that nothing life-like could evolve in a hot star, or on a completely frozen lump, because there aren't enough stable complicated structures. As for whether specific details like water are needed, we don't really have any compelling reason to think so.
3. I don't know who wrote that answer or what their justification was. We don't even know whether the phrase "in the very beginning" makes any sense, because we don't know what the form of spacetime would be at the start of the Big Bang, where quantum mechanics and gravity are both important.

I hope this serves as a small start.

Mike W.

(published on 10/22/2007)

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