Monthly Archives: August 2013

I Had a Dream

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People say that listening to other people talk about their dreams is boring. Freud found them interesting, but there’s a reason psychiatrists now listen to their patients for ten minutes before asking “How’s your supply of pills?” and finishing with “I’ll see you in three months”.

I don’t especially enjoy hearing other people’s dreams either. The ones with lots of strange things happening can be especially hard to follow. 

Still, dreams aren’t the most boring topic of conversation by far. Most of us understand that the most boring topic of conversation is “home improvement”, as in “here’s what we’re going to do with the windows in our living room”.

It should also be noted that some dream conversations are better than others. For one thing, the short ones are better than the long ones. Or if a co-worker says “I dreamed that you and I were in a space station orbiting the earth”. That might be of interest. Or if your spouse tells you about a recurring dream in which he or she sets fire to your hair. 

All of which brings me to a dream I had a few years ago. It was quite short, but also quite scary. If you want to hear it, keep reading.

All of a sudden, the world ended. Everything disappeared. Not just for me but for everyone. Realizing that I was dead but still conscious, I said to myself something like: “Oh no, they were right!”

Which meant that the stories about life after death were actually true! 

Then I woke up. It was still dark but not as dark as the void I’d escaped.

Being back in the world was a tremendous relief. The idea that I was going to be eternally alone in the darkness, doing nothing but thinking and remembering, was truly terrible. Because it wasn’t going to be for a very long time. It was going to be forever.

I can’t think of anything I’d want to do forever, except sleep. That’s the point of resting in peace.

The Uncertainty Principle and Us

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It’s difficult to discuss physics if you aren’t a physicist or don’t understand the math involved. Nevertheless, what physicists tell us about the world is so strange that it’s hard not to discuss it sometimes, whether we understand it or not. (The brilliant physicist and all-around cool guy Richard Feynman once said that nobody understands quantum mechanics, but some understand it better than others.)

There are philosophers who specialize in the philosophy of physics and aren’t shy about discussing physics at all, among themselves and with physicists. One of these philosophers, Craig Callender, has recently written two interesting articles for the New York Times. In these articles, Callender argues that Werner Heisenberg’s uncertainty principle, probably the best-known part of quantum mechanics, shouldn’t be as famous as it is. 

Heisenberg was one of the founders of quantum mechanics. He published the uncertainty principle in 1927. If you look up “uncertainty principle” now, you’ll find statements like this: “The position and momentum of a particle cannot be simultaneously measured with arbitrarily high precision” and “The uncertainty principle is at the foundation of quantum mechanics: you can measure a particle’s position or its velocity, but not both.”

Well, here is Callender on quantum mechanics:

[Quantum mechanics is] a complex theory, but its basic structure is simple. It represents physical systems – particles, cats, planets – with abstract quantum states. These quantum states provide the chances for various things happening. Think of quantum mechanics as an oddsmaker. You consult the theory, and it provides the odds of something definite happening….

The quantum oddsmaker can answer … questions for every conceivable property of the system. Sometimes it really narrows down what might happen: for instance, “There is a 100 percent chance the particle is located here, and zero percent chance elsewhere.” Other times it spreads out its chances to varying degrees: “There is a 1 percent chance the particle is located here, a 2 percent change it is located there, a 1 percent chance over there and so on.”

According to Callender:

The uncertainty principle simply says that for some pairs of questions to the oddsmaker, the answers may be interrelated. Famously, the answer to the question of a particle’s position is constrained by the answer to the question of its velocity, and vice versa. In particular, if we have a huge ensemble of systems each prepared in the same quantum state, the more the position is narrowed down, the less the velocity is, and vice versa. In other words, the oddsmaker is stingy: it won’t give us good odds on both position and velocity at once.

Callender then points out that he hasn’t said anything about measurement or observation:

The principle is about quantum states and what odds follow from these states. To add the notion of measurement is to import extra content. And as the great physicist John S. Bell has said, formulations of quantum mechanics invoking measurement as basic are “unprofessionally vague and ambiguous.” After all, why is a concept as fuzzy as measurement part of a fundamental theory?

Callender later shares another quote from J. S. Bell (considered by some to be the greatest physicist of the second half of the 20th century):

What exactly qualifies some physical systems to play the role of “measurer”? Was the wavefunction [the quantum state] of the world waiting to jump for thousands of millions of years until a single-celled living creature appeared? Or did it have to wait a little longer, for some better qualified system … with a Ph.D.? If the theory is to apply to anything but highly idealized laboratory operations, are we not obliged to admit that more or less “measurement-like” processes are going on more or less all the time, more or less everywhere?

When physicists use their instruments to measure a subatomic particle’s position or momentum, the instruments affect the particle. It’s the interaction at the subatomic level between the instrument and the particle that’s important, not the fact that the interaction has something to do with measurement, observation, mental energy or human consciousness. We aren’t that important in the vast scheme of things.

Viewing the theory of quantum mechanics as a cosmic oddsmaker may seem unhelpful. We want to know what’s going on at the subatomic level that results in the theory calculating certain odds. Heisenberg thought physicists shouldn’t even think about an underlying reality — they should simply focus on the results of their observations. But some (many?) physicists working today believe that quantum mechanics is an incomplete theory that will eventually be replaced by a more fundamental theory, possibly one that explains away the apparent randomness that exists at the subatomic level (that’s what Einstein thought too). Their hope is that uncertainty will one day be replaced by certainty, or something closer to it.

If you do a Google search for “uncertainty principle consciousness”, you’ll probably get more than 8 million results. If you search for “uncertainty principle measurement”, you can get more than 32 million. Professor Callender thinks those numbers should be much, much smaller.

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This is Callender’s first article in the Times:

http://opinionator.blogs.nytimes.com/2013/07/21/nothing-to-see-here-demoting-the-uncertainty-principle/

Here he responds to questions and criticisms from readers:

http://opinionator.blogs.nytimes.com/2013/07/25/return-of-the-stingy-oddsmaker-a-response/

Time Reborn: From the Crisis in Physics to the Future of the Universe by Lee Smolin

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The theoretical physicist Lee Smolin has written 4 books. I’ve read 3 1/2 of them.

His first book, The Life of the Cosmos, applied the theory of evolution to cosmology. Smolin suggested that our universe might be a good home for life because universes breed new universes, which differ somewhat from their parents. Over time, a universe with lots of black holes will generate a number of new universes with lots of black holes, and universes with lots of black holes tend to be hospitable for life, since their fundamental constants (like the strength of their subatomic forces) have values that permit life to evolve.

His next book, Three Roads to Quantum Gravity, was too technical for me, but I did finish his 3rd book, The Trouble With Physics. In that one, he argued that string theory is much too popular among physicists, since it isn’t a proper scientific theory. It’s too speculative and might never generate testable predictions.

Now there is Time Reborn. This is a kind of sequel to Smolin’s earlier books. He still subscribes to the evolutionary views presented in The Life of the Cosmos, but his principal thesis now is that time is real. In fact, time is more real than space. This contradicts the common view among physicists and philosophers that space and time are the four dimensions that make up “spacetime”. The standard view among physicists is that all events, whether past, present or future, are equally real. There is nothing special about the present moment. In fact, our perception that time passes is an illusion.

Smolin argues that this consensus view of the universe as a “block universe”, in which all moments are the same, is a mistake. He agrees that the laws of physics and the equations that express them can run forwards or backwards, but only on scales smaller than the universe as a whole. The planets could revolve the other way around the sun, just like clocks can run in reverse. But the universe as a whole has a history that is real and a future that isn’t determined. Smolin thinks that treating time as real might help resolve certain issues in physics, such as the “arrow of time”, i.e., the fact that certain processes always go in one direction (entropy tends to increase in isolated systems).

Professor Smolin tries to explain how his view of time fits with Einstein’s special theory of relativity (in which temporal properties are relative to an observer) and how something can act like a particle and a wave at the same time (as shown by the famous “double-slit” experiment). I don’t know if those explanations or some of his other technical explanations make sense. But it was reassuring to read a book by a reputable physicist who believes that time is real, physicists have overemphasized the importance of mathematics in understanding the universe, and there is a reality beyond what we can observe. Smolin also believes that there are probably more fundamental, deterministic laws that underlie quantum mechanics. I believe that’s what Einstein thought too.

Time Reborn veers into philosophy at times. There is much discussion of the Principles of Sufficient Reason and the Identity of Indiscernibles. The book concludes with some comments on subjects that aren’t physics, like the nature of consciousness. Smolin’s philosophical remarks are relatively unsophisticated. I assume his physics is better.

Even if he’s wrong about the reality of time, however, I enjoyed the book. For one thing, I can now see how two particles at opposite ends of the universe could be “entangled”, such that a change to one would automatically result in an immediate change to the other. Space might have more dimensions than we recognize. In another spatial dimension, the two entangled particles might be very close neighbors, making what Einstein called “spooky action at a distance” (“spukhafte Fernwirkung“) less mysterious. That makes me feel a lot better.

If You Have Nothing To Hide

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Earlier this week, Reuters reported that certain information collected by the National Security Agency is shared with the Drug Enforcement Agency, allowing the DEA to arrest people on drug charges. Furthermore, in order to keep the source of the NSA information secret, the DEA commonly invents a “parallel construction”, i.e. an alternative history that can be presented as evidence in court. DEA agents claim that they discovered the subject criminal activity using ordinary methods, not information from the NSA.

That’s commonly called “lying” or “perjury”. 

From the Reuters article:

The unit of the DEA that distributes the information is called the Special Operations Division, or SOD. Two dozen partner agencies comprise the unit, including the FBI, CIA, NSA, Internal Revenue Service and the Department of Homeland Security. It was created in 1994 to combat Latin American drug cartels and has grown from several dozen employees to several hundred. 

There hasn’t been much reaction to this story so far. But it does raise some interesting questions. For example, is the NSA sharing information with other government agencies? Are other agencies, not just the DEA, using the NSA to keep an eye on people they have an interest in, like supposed tax evaders, members of organized crime, political activists and troublesome journalists? 

More generally, how much government surveillance should be permitted in a democracy, especially one as flawed as ours?

(Not that there’s anything wrong with secret, widespread government surveillance. Whatever the government is doing is perfectly fine with me. Keep up the good work, guys! I’ve got nothing to hide, so no complaints here. You can trust me. Really! But you should check out those odd people across the street.) 

http://www.reuters.com/article/2013/08/05/us-dea-sod-idUSBRE97409R20130805

What I Should Have Said

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Earlier tonight, I left a comment on someone’s blog. The topic of her post and my reply was wanting more friends. Here’s my comment:

When I was in my early 20s, I once told someone “I have no friends”. He questioned this and asked me if there was anyone I could borrow money from.

I could have borrowed money from him. But clearly we had different definitions of “friendship”.

As soon as I wrote that, I realized the last sentence wasn’t needed. Without that last sentence, my comment might have had a koan-like quality. I can’t change it now, but maybe I could ask the blog’s owner to strike that last sentence? And maybe do some more trimming:

I once told someone “I have no friends”. He asked me if there was anyone I could borrow money from.

I could have borrowed money from him.

Much cleaner. It’s probably greeting card-worthy.

But wait a minute! The point of your comment was to share a thought with someone who was feeling low. You thought you could give her a different perspective on making and keeping friends. That was the important thing, right? Stop worrying about how you said it. It’s not as if people are going to be reading these blog posts 1000 years from now, you neurotic jerk! In fact, you could have been even more explicit — talked about staying in touch with people you like, pointing out that having three very close friends is more than many people have, you know, that kind of thing.

Ok, I get your point. Sorry to make such a big deal about it. But just in case people are reading this stuff 1000 years from now, maybe I could tweak it a little?