Harriman doesn’t understand physics

In some respects, physics is not in a very good state. In particular, many physicists are instrumentalists: they see physical theories as instruments for predicting the results of experiments rather than as explanations of what is happening in reality.

There is some resistance to instrumentalism among some physicists and members of the public. But a lot of this resistance takes the form that the laws of physics have to conform to some version of common sense. But common sense is just knowledge that people currently happen to think ought to be uncontroversial. So to say that some idea doesn’t conform to common sense is not particularly relevant to judging that idea. Rather, the idea should be taken seriously as an explanation in its own right. This includes understanding the claims the theory makes about measurement. What sort of physical processes constitute measurements, what sort of limitations do those processes put on what attributes of a system can be measured and so on.

David Harriman is a common sense advocate, and has many of the weaknesses of such people. Harriman writes an article that includes dialogues between a physicist and a layman. The physicist is an intrumentalist and the layman is a common sense advocate.

First, I’ll look at a part of the dialogue about relativity:

P:  “There was a theory that treated length contraction and time dilation in that way. It was proposed by a Danish physicist named Hendrik Lorentz. On the basis of his theory, Lorentz derived some of the fundamental equations of relativity before Einstein did. But the Lorentzian theory was rejected and replaced by Einstein’s theory.”

L:  “Was Einstein’s theory accepted because it was better able to account for the observed facts?”

P:  “Not exactly. The basic advantage of Einstein’s theory is that it’s simpler. He dismissed the idea of explaining the phenomena of relativity by reference to any physical stuff in space (the so-called ether). Instead, we just say that moving bodies appear shorter and moving clocks appear to run slower—as perceived by a stationary observer. In other words, space contracts and time dilates by amounts that depend on the relative motion with respect to an observer.”

L:  “But I want to understand the cause of these effects. You say that length contraction and time dilation don’t refer to real physical changes in moving bodies. Do they instead refer to real effects on our measurement of lengths and times? I remember hearing a classical physicist explain that heating a ruler causes it to expand and thereby affects length measurements. Does motion also affect our physical means of measuring lengths and times? If so, I could make sense of relativity theory. There would still be real lengths of bodies and real time intervals; we merely have to account for and subtract the effects of motion on the measurements. After all, the actual properties and relationships of other bodies can’t change whenever I decide to move!”

If I take a picture of a book from two different angles, the measurements I make relative to the sides of the picture may be different, as in the two pictures below:

The book didn’t change as a result of my taking a photo from a different angle. The constitution of the camera didn’t change either, it still operated the same way after I turned it. The only thing that changed was the relationship between the book and the camera. So different relations between two objects can change the results of measurements even if the two systems operate the same way before and after the change. You can tell that the book remains the same because there are features of the book that remain the same in the two photos, such as the length of the bottom edge of the book compared to the letters on the cover. You could say that those are the real measurements of the book since they remain the same in the two photos, but it is also the case that there is a set of objective facts about the results of measurements on the two photos. Physics ought to tell us about both sets of facts. So the results of some measurements can depend on relations between two bodies.

The layman in the section of dialogue quoted above claims that the relationships between body 1 and body 2 don’t change when body 2 moves. This is a bizarre claim since the relative state of motion of two bodies is a relationship between them. So why shouldn’t some measurements change as a result of different states of relative motion? That is the explanation for the difference in length and time measurements given in standard accounts of special relativity, such as Special Relativity by A. P. French. Note also that as in the case of the photos book above, special relativity claims that some features of a system’s behaviour don’t depend on its relations to other objects. For example, if two atoms emit a photon, the time at which I see each atom emit the photon will in general depend on my state of motion relative to the atoms. And the distance I see between the atoms will also depend on my state of motion relative to the atoms. But the quantity where $latex \delta x$ is the distance I measure between the atoms, and  is the time between the photons being emitted. Special relativity is different from what people expect from everyday life, but it is consistent and explains the world better than common sense.

In the dialogue on quantum mechanics his confusion is more understandable. The sort of nonsense the physicist in the dialogue utters is not very far from what a lot of physicists say about quantum theory. But this is a problem with how physicists explain the theory not with the content of the theory itself. And there is a notable symmetry between the two sides of the dialogue, illustrated by the quote below:

L:  “I still don’t understand. If you observe only specific entities with definite properties, and you know of no mechanism by which an inconceivable ‘nothing in particular’ could suddenly acquire such properties, why not accept the fact that these things possess real attributes before the observation?”

P:  “Because we’ve concluded it isn’t possible to develop a theory that explains our experimental results in terms of entities with specific, non-contradictory properties.”

Note that both sides of this dispute talk vaguely about properties, with specifying what properties they are discussing. Neither side gives any explanation of how reality actually works. There is no discussion of any specific experiment, nor of explanations for the outcomes of these experiments. Both sides are discussing the issue entirely in terms of abstractions that float free of all problems, all experimental results and all solutions to problems. There is an explanation of what quantum mechanics says about how the world works. But you can’t understand that explanation by starting with vague mumbo jumbo about properties, as do both Harriman and the standard physicist.

The EU and the ‘who should rule’ question

In political and moral debates people often make false assumptions that limit the set of options they can imagine as a solution. I think this is happening in the debate over whether the UK should remain a member of the EU. The issue is being framed as whether bureaucrats from the EU should be able to dictate what sort of laws the British parliament should pass or whether the British government should control its own laws.

But this way of framing the debate makes a false assumption that the most important issue is who gets to make a decision about UK laws. As Karl Popper pointed out in The Open Society and Its Enemies Chapter 7, this question makes the false assumption that there is a single person or group who has the knowledge required to dictate what everyone should do. A better question to ask is ‘How can we so organize political institutions that bad or incompetent rulers can be prevented from doing too much damage?’ How do the EU and the British parliament compare by that criterion?

The short version of how the EU works runs as follows. The heads of EU states form the European Council. The European council picks a group of politicians called the European commission who are responsible for originating and writing EU regulations and that sort of thing. The European parliament is an elected body who can vote up or down legislation written by the European commission, or amend it, but are not allowed to originate legislation. So the people who are legally supposed to originate and write all the laws can’t be voted out of office by the public. The people who are subject to being removed by the public always have the excuse that they aren’t allowed to originate laws, so they can’t deliver any specific policy.

By contrast, an MP in the British parliament can originate, amend or revoke laws and can be voted out for failing to deliver on policy promises.

The competition for which set of institutions is better isn’t even close. The EU is a bad idea and the British public should vote to leave. If we don’t vote to leave, then it will be extremely difficult to remove bad policies or leaders.

The poor quality of the EU’s institutions shows in its decisions. Take the recent deal made by David Cameron on behalf of the UK. One part of the deal says that EU parliaments can block EU legislation if the EU deems that the decision could be made at the national level and 55% of the parliaments of EU member countries vote against it. Getting one parliament to agree on something is a challenge, getting several to do so is going to be extremely difficult. This is a terrible idea that should have been shot down, but it wasn’t because there is nobody who can be held accountable for it. Why make waves if you can’t benefit?

AI prophecies

There is an idea doing the rounds that soon Artificial Intelligences will be created that will be capable of doing all the jobs people can do and this will require introducing a universal basic income. Let’s call this the UBI scenario.

The story goes like this. AIs will be capable of doing all the jobs people can do. And all they will need is some computer hardware and electricity. And they won’t want food, they won’t want time off, they won’t have personal problems and so on. So they will be able to do every job better than people.

First, what’s currently called AI doesn’t have anything resembling human level creativity. The way this works at the moment is that somebody has to think about what information is relevant to judging how well to do a task. The person also has to think about what sort of parameters characterise the task. And then the person has to train the program by running many versions of it and selecting the version that works. So to replace any given job will require years 0f work, specialised hardware and software and a lot of time spent by a highly specialised programmer. The fact that job X has been rendered unnecessary will free people up to do other stuff. And it will take time for people to create knowledge about how to do that job well, before the process of replacing them can even get started.

Second, lots of jobs do require human level creativity, such as just about any customer service job. The customer service person has to be able to think about how to satisfy a particular customer on the fly. And each customer will want something slightly different. So there will be no way to replace that customer service job with a special purpose machine designed to do some specific kind of mechanical task.

If you are worried that AI’s will have human level creativity, then don’t. That will not happen for the foreseeable future. Nobody has much idea how the creation of new explanatory knowledge works, except that it involves producing variations on current knowledge and selecting among those variations. Given that we don’t have a full explanation of how creativity works, there is no way anyone can program it.

The UBI scenario is speculation about a technology that doesn’t exist. It also involves speculating about a situation in which there has a vast increase in philosophical knowledge about how people create knowledge. Nobody can know the implications of such knowledge because if you knew its implications, then you would already have that knowledge. The idea that having such knowledge will reduce people to the status of dependents suckling on the state’s teat reveals a bias on the part of those proposing the UBI scenario and nothing else.

To illustrate one way in which the UBI scenario might be wrong, consider the following story. I don’t say this is what will happen, but it is an alternative that illustrates that UBI scenario worries are pure speculation uncontrolled by criticism. In the future we understand how to create knowledge well enough to create AI. As a result, we learn how to make adults creative after life has beaten them down, and everyone becomes extremely productive. Every person is able to support himself with no government assistance. At the same time, we learn how the brain implements creativity, and how to read a person’s brain in such a way that their mind can be implemented in a computer. So people can then transfer their minds into computer hardware and the cost of living drops to the cost of buying the relevant storage space and processing power in a server farm. So then everyone can afford to simulate a standard of living that makes everything Bill Gates has today look like the life of some drunken lice ridden peasant in the Middle Ages by comparison.

There are lots of serious problems with current institutions. For example, Western welfare states already encourage dependence on the government without AI. Academics are an example of this problem: they are dependent on the government for their income. Perhaps they should try to solve that problem instead of speculating about stuff they can’t know anything about.