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On the nature of physics

Luboš Motl says Learning physics is futile without practicing but it’s not practice he is talking about.

“Physicists have the working knowledge of all the things in the Universe – OK, I mean all the important things in the Universe – but they only have it if they can actually think. … they have mastered a sufficient chunk of maths that is needed to connect the statements about physical phenomena with each other and with the mathematical expressions, structures, and propositions.

At the same moment, I would agree that too much exercising becomes useless, too. Physics – and research-level maths – is ultimately not about following some procedures and protocols infinitely many times. We want to find new ones. … A person who has the curiosity of a physicist simply wants to learn new things that are qualitatively different from the things he has already learned.

So I want to say that it is indeed natural if a physicist doesn’t want to spend too much time with practicing the same thing. Engineers or athletes spend much more time by doing the same things all the time – which may ultimately be a good idea for practical or financial reasons. A physicist wants to get as far as he can in his mastery of the Universe or its chosen part. On the other hand, and this is what the title is about, a certain amount of practicing is simply necessary even for the most exercise-hating physicists because it’s needed to guarantee that the knowledge is genuine and usable.”

“When the amount of ignorance and the number of holes grow too large, you not only fail to know many particular things but you also lose the idea about how many things you’re actually ignorant about and how to ask questions that would give you a chance to fill the holes, and so on. Your physics knowledge becomes unusable.”

“To meaningfully answer such questions and to have an idea how many details the answer should discuss, one needs to know how much the person who asks something actually understands.”

“physics differs from literature or many other subjects – that often include natural sciences – where the structure of the background isn’t hierarchical or is much less hierarchical than in physics.”

“String theory is arguably the tip of a pyramid of knowledge that has almost as many floors as the Empire State Building, if I count if in a fine-grained way. Memorization of an isolated insight or rule is almost worthless in physics because the meaning and power only emerges when many prerequisites are understood.”

“Needless to say, this is why some people hate physics – and maths – at school. If I don’t count gyms and similar things, almost all other subjects at school are about memorization, a universal method that requires lots of RAM (or hard disk space) and almost no CPU or GPU, if I compare the students to computers. At most, some subjects require that the students learn how to follow a relatively mechanical procedure or two to “derive something”.

Paradoxically enough, it’s the same people who don’t like maths and physics for their “requirements of creativity and practicing” who most frequently complain that maths and physics are mechanical, dull, narrow-minded, isolated from practice, and that they reduce people to mindless mechanical machines. When you look rationally at the situation, you notice that the truth is exactly the opposite. These critics of maths and physics are the mindless unthinking machines that only do mechanical things and they hate maths and physics exactly because they can’t be mastered in this way! ;-)”

What got him going was some of the questions on the Stack Exchange. That is, people seeking simple answers to complex questions; people who think they know more than they really do; people trying to rationalize what they want to be rather than what really is. That sort of things tries the patience and what makes androgogy much more difficult than pedagogy.

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