Recent content by Over My Head

It now seems obvious to me that I was failing to factor in the atmosphere that would need to be maintained, rather than the inside of the "thing" being a vacuum.

So in simple terms, the released ball has a linear momentum, but the curved surface moves in a way that intercepts the ball in its trajectory, making it appear to the person releasing the ball that it "fell" to the "floor?" It sounds like this WASN'T such a silly question after all.

But work IS being done on the book? I would have thought that by swinging the book, the muscles of the arm would be doing work on the book?

It sounds as if while you are holding the book motionless relative to yourself, no work is being done on the book. If you are moving the book relative to yourself, it is. For example, if the book is in your hand and your arm (not the other one, of course...) is swinging while you walk, is work...

One more thing - I assume that although friction would bring you up to speed, you wouldn't be held against the interior?

Thank you! Every time I see or read the sci-fi "artificial gravity" through spinning device, I wonder why people and objects in contact with the interior of the spinning "thing" in space don't just bounce along, and why things not in contact with the interior would be drawn to it.

I hope this is the right place for this question. How would spinning a ship in space create artificial gravity? I've long wondered if it actually would, or if you'd just have people floating in a spinning ship. I did a minimum of searching and found that there have been actual proposals...

Is that a generally accepted, or at least mainstream, concept?

Sorry, I think I added to my post while you were responding. Thanks for the input!

So would that theory say, basically, that the universe is always finite, but will infinitely continue to grow (or expand, if you prefer)? Would that mean that the "space" into which the universe expands doesn't exist until it is reached by the expansion? Or is the "space" there, but unoccupied...

Thanks for the vote of confidence! I have determined to dedicate a portion of my free time to learning more about physics. Of course the pie chart that represents my free time is largely taken up by family (wife and 3 Beagles), work, and writing. And yes, I'm a proponent of the Oxford comma for...

I'll have to look into that. One ofmy favorite quotes is "Imagine what we'll know tomorrow." I don't remember who said it, and I'm not going to look it up right now!

If I refer to direction in the context of toward or away from, I'm only speaking in terms of relative to another object. I thought it was fairly well accepted that the universe is infinite, but as I said in my original post I'm a novice and dabbler and am just starting to educate myself about...

Thanks for the replies! mbf: My problem with this is that since the universe is infinite, and we can't detect things that are infinitely far away, do we really know whether the expansion is toward anything? Is it only the known portions of the universe that are expanding, or is it possible...

I am a novice and dabbler, but very interested in the evolving understanding of the laws of nature. Most recently, I was listening to a discussion about the surprising discovery (granted, not a new discovery) that the universe is expanding at an increasing rate rather than at a decreasing rate...