Hardly anyone has written anything about Chapter 3, so it may be too soon to move on to Chapter 4, but I really like it.
It's quite long and involved, so perhaps there will be many posts about Chapter 4 and we'll discuss it long enough to let everyone catch up.
The first thing I liked about Chapter 4 is the poetic language. The undeserved miracle of mathematics, the light scattering off sheets of metal, the dance of subatomic particles, the Ionian Enchantment, the emotional consequences of having our alarm clock vaporized by an alien laser -- what a lovely chapter!
I also like spacetime. It seems to me to fix a lot of the things about space and time individually that make us dizzy. And, while I was a bit dismayed to see the Aging Twin again, I thought they did a good job at presenting the paradox in a slightly newer and more interesting way.
What did you guys like in Chapter 4?
My first thought is that Chapter 4 is too long. I'll have more insightful comments tomorrow.
ReplyDeleteI agree with you. They should have broken it down into two or three chapters.
ReplyDeleteI know this really relates to Chapter 3, but the whole idea of getting more out of each second by moving really fast is so appealing. I know that's not what this is about, but I am so drawn to that idea of slowing down time.
ReplyDeleteThe first part of Chapter 4 is somewhat jarring to me. In previous chapters, the authors have spent much effort convincing me that everything is relative. We can't define movement except as relative to something else. I was OK with that. Now, in the discussion of invariance, they are taking the stand that some things are not relative. Some rules are absolute. I'm OK with that too, but I have to say my first reaction was "What?"
ReplyDeleteThat's actually a fair point, Janet. Perhaps the ideas of relativity and invariance aren't related in that way.
ReplyDeleteIf invariance is like the car that we know will start anywhere, perhaps the relative part is the motion aspect.
Or perhaps variance is a control group of sorts.
We might need to bring in a ringer on this one... someone who knows more about this to explain where we've gotten ourselves confused.
I don't think that everything is relative.Time and space, yes. We have a location only relative to other stuff, not an absolute location. And, oddly enough, we exist in time only relative to other stuff, though I don't think that comes up a lot in daily life.
ReplyDeleteI haven't actually been convinced before that the speed of light was a constant. I mean, I knew that it was, but I thought it was like the concert A -- it was a constant because we all agreed that it was. I found the authors' arguments about that convincing, though.
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ReplyDeleteI think the point here is that for some reason we feel like time cannot be manipulated because of common sense. We think of the passage of time as something that cannot change, as a law of nature. What the author is saying to me is that there are still laws of nature, and often we recognize that as the passage of time. But it really is something else. It's this idea of invariance. Under normal circumstances, invariance is manifested in the passage of time. If, however, we can figure it out, there are circumstances under which time becomes another dimension that can be manipulated.
ReplyDeleteIn a way this all makes me thing of the painting "Nude descending a staircase." (http://en.wikipedia.org/wiki/Nude_Descending_a_Staircase,_No._2)
The artists goal in that painting, as I understand it, was to paint what we see over time rather than what is actually there. In a way, the painting is more accurate than our own eyes. Well, what if the painting is actually close to reality than we thought. Maybe it's what is really there and our eyes are showing the distorted view.
I think the authors at one point say that our perceptions are based on what is useful to us. We can only travel in one direction in time, so it's most useful for us to perceive time differently from space.
ReplyDeleteIf we imagine traveling in spacetime, then we can think of ourselves as using part of our energy to travel through time, part to travel forward or backward, part to travel up or down... But if it actually felt like that at the time, we'd get that Alice down the rabbit hole feeling Rosie was describing.
That painting is one of my favorites.
How are we doing? I read ahead a bit...through Ch 5 and 6 and I feel like my eyes are getting glazed over. Chapter 5 seemed like one theory after another...like watching someone talk about something they are really excited about but not really understanding. I appreciate the excitement, and don't mean to be negative, but there are some basic concepts that I must have missed somewhere. First of all, there's fission and there's fusion. I remember that much. One is bad (makes bombs) and one isn't. I think they are talking about the good one. I wish they would explain that more.
ReplyDeleteIn chapter 6 they talk about the enormous potential for energy. That's great, but how does that interact with global warming? It's great that we can create energy without burning coal, but I missed the explanation of how that is really better for Mother Earth.