Sunday, April 6, 2014
Yeah, kiss it!
I was busy in the kitchen cleaning or cooking or something and not paying that much attention to my wonderful little girls. My littlest was trying to get my attention and I was trying to work around her when she slipped and knocked her head against the wall. She didn't knock it hard so I wasn't worried, but it was very upsetting to her to bump her head on top of being ignored. So, she softened my heart a little and I knelt down to ask her what happened. Now, Faith can't talk well yet so it was good I already knew what had happened. But I listened to her explanation and repeated back to her what I had seen. Then I asked her where she had bonked her head, and she pointed to the spot on the wall. And I kissed the wall. It took her about a half second to process what had happened before she said, "Yeah, kiss it!" And happily toddled off.
Saturday, April 5, 2014
The universe could be finite
There is an old bit of philosophy that argues that the universe is infinite. It goes something like this:
imagine that the universe if finite. There must be an edge to the universe, a cliff or perhaps a wall. Let's say it is a wall. If you go to the top of the wall and look out, there is something on the other side of the wall. The wall divides something. So you go to the other side of the wall and explore only to eventually find another wall marking the edge of the universe. You climb up that wall and see that it divides something ... ad infinitum
It occurs to me that this is bad logic. There need not be anything on the other side of the wall. It relies on our daily experience with land being divided by walls. This need not apply to a universe. Imagine that the matter and energy ratios are such that the universe will eventually collapse into a black hole. You would then find that you have a very finite universe. There need not be anything outside the event horizon. There need not be space, matter, energy, light ... nothing can get out. The universe would be a closed finite system.
It appears that this is not the case in reality. I am just saying that the logic was flawed. My argument is flawed as well. I was just trying to get the reader to the point where they could start to imagine an enclosed finite universe without creating a monstrous treatise.
In reality, in the case of a big crunch, I believe that a vast amount of energy in the form of light from the initial bang would continue to expand out into space, or the void if I may. I also think that void, due to quantum uncertainty is actually filled with virtual particles and that these must already exist in the regions into which our universe expands. And that the void exists. But as physics progresses, I suppose we may find that void is finite. There is a lot that could be said on this topic. But this is enough for now.
imagine that the universe if finite. There must be an edge to the universe, a cliff or perhaps a wall. Let's say it is a wall. If you go to the top of the wall and look out, there is something on the other side of the wall. The wall divides something. So you go to the other side of the wall and explore only to eventually find another wall marking the edge of the universe. You climb up that wall and see that it divides something ... ad infinitum
It occurs to me that this is bad logic. There need not be anything on the other side of the wall. It relies on our daily experience with land being divided by walls. This need not apply to a universe. Imagine that the matter and energy ratios are such that the universe will eventually collapse into a black hole. You would then find that you have a very finite universe. There need not be anything outside the event horizon. There need not be space, matter, energy, light ... nothing can get out. The universe would be a closed finite system.
It appears that this is not the case in reality. I am just saying that the logic was flawed. My argument is flawed as well. I was just trying to get the reader to the point where they could start to imagine an enclosed finite universe without creating a monstrous treatise.
In reality, in the case of a big crunch, I believe that a vast amount of energy in the form of light from the initial bang would continue to expand out into space, or the void if I may. I also think that void, due to quantum uncertainty is actually filled with virtual particles and that these must already exist in the regions into which our universe expands. And that the void exists. But as physics progresses, I suppose we may find that void is finite. There is a lot that could be said on this topic. But this is enough for now.
insight from a conversation with Dad / more evidence of photons
Last night I was driving home from a long field job. I was exhausted and it was showing in my driving quality. I needed help staying awake, so I called my Dad. I had nothing to talk about, but just needed to keep talking to help me stay awake. My Dad was kind enough to go over some things he had been thinking about. And in the midst of this groggy conversation I had a new insight into light. It may not seem like much, but here it is:
If light were a wave like sound waves or water waves that traveled on some medium (water or air), we wouldn't be able to see the stars. The energy would diffuse over so much distance. But because light is made up of discrete packets of energy, photons, that exist independent of everything else around them we get to see the stars at night. There is an underlying assumption here that the medium is fundamentally granular. Air and water are both made up of lots of little atoms. Even sound traveling through a more rigid material like steel is made up of lots of little atoms. This granular nature is what causes the wave energy to disperse over a distance. But light being made up of its own little particles can only disperse down to single photons. After that it cannot get more dispersed.
If light were a wave like sound waves or water waves that traveled on some medium (water or air), we wouldn't be able to see the stars. The energy would diffuse over so much distance. But because light is made up of discrete packets of energy, photons, that exist independent of everything else around them we get to see the stars at night. There is an underlying assumption here that the medium is fundamentally granular. Air and water are both made up of lots of little atoms. Even sound traveling through a more rigid material like steel is made up of lots of little atoms. This granular nature is what causes the wave energy to disperse over a distance. But light being made up of its own little particles can only disperse down to single photons. After that it cannot get more dispersed.
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