Time flies when you're having fun

My last post was March 15th? Wasn't that, like, three weeks ago? Oh wait, that was just 6 days ago. Okay, that's not so bad.

Just got back from a trip down to Chapel Hill to see the parentals with my girlfriend. No particular reason for going other than to break up the long stretch of not seeing them from Christmas to some time in the summer. It was fun. I have a hope, most likely of the irrational kind, that I have a chance of being somewhat decent at golf this year. I will definitely be playing, weather-permitting, the weekend after next. As long as I putt it from anywhere inside 100 yards, breaking 110 may be a possibility.

There are few situations better than being on a plane with a good book. You can't go anywhere...there is no "opportunity cost" from just sitting there and reading...so it is when the return on reading is at its peak. On this trip, I was able to spend a decent amount of time reading my current book, The Fabric of the Cosmos by Brian Greene. It's great. As a resident of what we call the Universe, it's kind of our duty to read this book and make at least a good faith effort to understand how this thing we call the Universe, also often referred to as "reality", works. In any event, I have two questions for Mr. Greene, which I hope we can discuss in earnest one day over a couple of beers at The Warren Tavern:

1) I have just finished Part II, Time and Experience, and I have a question. It seems that there is open debate in the phyisics community today as to the merits of even exploring the quantum measurement problem. (A quick primer for the lay-people out there (such as myself): thanks to school curricula that seems to lag at least two decades behind the forefronts of science, we were taught that something like an electron is this little sphere...this very small "spec" of something. But it really isn't. It is actually a wave of probability. It's a wave that carries the various probabilities of the potential that the electron will actually be here, or perhaps there, when it interacts in some way with another object. I used to think of this as a "blur"...as in something we see in everyday life when something is moving very fast, such as those Sharper Image clocks where you see the time projected over this fiberglass wand that moves back and forth very fast. Looking at the blur, you don't see the wand itself. But, at any given moment, you know that there is a wand, and that it is somewhere within that blur and moving with a definite speed. But today I know that that is not a probability wave. In a probability wave, there really isn't a wand that is definitely here or definitely there. The only thing that is "in" a probability wave is a set of probabilities that, when you "look" at the wand, it's going to be here, or there, or there. I know that is weird, but just go with it for now. And the thing that makes that wave "collapse" to one point..the point where the classic electron that you think of actually is, is when it interacts with an outside object such as another electron, etc. There is no debate among physicists regarding the theory of how to know the various probabilities in the wave over time. But the actual mechanism of how that wave collapses to that one point, and why it collapses when it contacts, or is "measured" by, a foreign object, is a mystery. This mystery is called the quantum measurement problem). It seems that some say that understanding the "why" and "how" of wavefunction collapse is irrelevant, because we do understand that there is a wavefunction and we know how to correctly predict the probabilities within it. And it seems that those opinions are viewed with legitimacy. But isn't there a double standard here? Isaac Newton's laws of motion were fantastically accurate at describing the relationship between mass and gravity. But they didn't explain what gravity is, or the mechanic by which it works. Many accepted the laws as is, and the lack of the mechanical explanation did not prevent mankind from reaching remarkable heights based on those laws, such as landing a man on the moon. But some continued to question. And one of those individuals, Albert Einstein, discovered a deeper truth (the curvature of spacetime) that opened up a whole new world of scientific inquiry. All physicists today would likely agree that it is better that some questioned Newton's laws as opposed to simply accepting them. So my question is, why is it seemingly considered a legitimate view on the part of a modern physicist that we should just accept wavefunction collapse as a fundamental truth, when if it wasn't for the "unreasonable intellectual greediness" (p.213) of our predecessors, we wouldn't even be asking the question?

2) This one is much simpler. The simple question is, in the decoherence framework, what makes a wave "cohere" after it has decohered? I can't find the page, but there is a discussion in that neighborhood about the time, in billionths of a second, that it takes a spec of dust to decohere in various environments. But that implies that there is a spec of dust out there in space, in the real world, that has an uncollapsed wavefunction. How did it go from being collapsed to being uncollapsed?

3) And for that matter, how can we extrapolate from a single photon or electron to a spec of dust, which is made up of billions of atomic elements? The whole basis of decoherence is that probability waves, which are the true nature of classical "particles" such as photon or electrons, decohere as soon as they interact with a foreign photon or electron. So how could a whole spec of dust be "cohered" in the first place?

I can't believe I've been writing this for an hour and a half. Because of the time sent, I will probably send this to Brian Greene.

Hope that you all had a good weekend. See you out there.