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3/3: Mathematical notation

Created: 13 Jun 2016

Modified: 12 Oct 2016

[Part 3 is about communicating mathematical ideas. Part 1, Part 2. I took care to contain the tedious math bits in single paragraphs, so the point is still clear if you choose to only read the fun parts.1]

summary. There is no such thing as “wrong” notation. All that counts is that you get the math right and communicate your ideas clearly.

Last time I explained how it’s not accurate to say that an electron “is” a wave function, because an electron is a thing in the universe and a wave function is a mathematical object, and mathematical objects don’t live in the real universe. When people talk about wave functions, they often use the letter $\psi$. Obviously, even though it looks all nice and wavy, the $\psi$ itself isn’t the wave function either – it’s just its name. The concept of names is one we know and love from the real world: When I point at a chair and say, “This is Bob,” it’ll be clear what I mean when I explain that Bob has three legs. While it’s a terrible idea to call a chair Bob, giving things and their relationships with each other funny names is basically what mathematics is all about.

  1. In the future, when I have a list of my most notable essays, this one will be “The Long, Confusing, Meandering One.” This is my A Feast For Crows in terms of exciting action; it’s my American Gods in terms of quickly getting to the point; it’s my Getting Things Done in terms of elegant phrasing – you get the idea. Think of this more as a piece of performance art, rather than an informative article. 

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2/3: Models

Created: 30 Jan 2016

Modified: 13 Jun 2016

[Part 2 is the best part. Part 1, part 3.]

In science, we try to understand the world by building models and theories that describe it. You see an apple falling on your head, think, “oh, maybe that’s how the planets move, too”, and you write down rules that allow for the motion of planets and don’t allow for some phenomena you do not see, like things falling upward. You call the collection of those rules your model, or theory. When you have your model, you perform more experiments to test it, and every time your model’s prediction roughly matches your observations, you get more confident that your model is correct.

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25 Jan 2016

People tell me I should go to a CFAR workshop and they may well be right, so it’s time to figure out how to prevent what is inevitably going to happen there from happening.

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1/3: Just The Way Things Are

Created: 28 Dec 2015

Modified: 13 Jun 2016

[Part 1 is about a feeling about the world. Epistemic state: Maybe I shouldn’t commit to writing blog posts about every thought that occurs to me while browsing Wikipedia. Part 2, part 3.]

I decided I don’t like the term “laws of physics” to describe the way reality behaves. Calling them laws makes them sound optional1. Like, it would be really good if you didn’t break them because they are being enforced by the space police, but if you’re really clever, you can outrun the space police and break them anyway. But you can’t.

  1. Weellll, this is arguably inaccurate, but the point is less about the terminology and more about the intuition, so whatev. 

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Waves of confidence

04 Oct 2015

There seems to be a distinct and relatively predictable pattern to my confidence/comfort levels when I’m meeting new people and I’m wondering whether this is a common experience.

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German EA landing page

26 Aug 2015

There is now a German translation of the EA landing page. It lives at www.effektiver-altruismus.de. Share it with all your German friends!

LessWrong Community Weekend 2015

29 Jun 2015

[Kinda sappy and emotional in parts. Being posted sort of a long time after the event. Not totally happy with the way this post turned out, but, you know, better finished and mediocre than perfect and imaginary, or something. Epistemic state: I deleted a lot of “as far as I can tell”s. Just pretend like every sentence ends with those words, and please do tell me if I’m wrong about anything.]

I attended this year’s European LessWrong Community Weekend. The initial draft of this post began thus:

This is the event report I did not want to write and you do not want to read.

I decided I didn’t like this approach. During the Weekend, people always said, “make it your own.” So let’s do that instead.

This is a collection of things I learned while I was in Berlin.

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Created: 02 Jun 2015

Modified: 13 Mar 2016

I have helped typeset three theses and many shorter documents in LaTeX and I realized that I find myself googling the same things over and over again. Therefore I decided to collect all the problems I have solved so far on this page. At the bottom there is a list of unsolved problems. The reader is invited to give me advice in the comments.

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