All of jd_k's Comments + Replies

jd_k30

doing gymnastics while doing household chores

Will you expand on this? I am intrigued.

5Gunnar_Zarncke
It basically started when I read that the deep back muscles cannot be trained by voluntary tensing but only by unconsciously during keeping balance. This appears to be oversimplisitic but it led me to the idea of one leg balancing in everyday situations. After starting to use it in a few limited situations (preparing fruit basket) I added more and more situations and now use it automatically in most situations that involve standing like washing, preparing meals, waiting for commute etc. It doesn't cost you any time adds some minor fun to many of these tasks and as far as I can see has reduced my back problems. Beside the balancing I started to add some more gymnastic-like motions to my program when I started fencing. E.g. when (un)loading the dish-washer I do quat-like or lounge step motions. When lifting things I focus on avoiding to bend over but instead use the 'correct' weight lifting motions. And I take the fencing stance or parts thereof as often as I can. I can't remember where I read about this. Could have been this source (German) or this one. After quite some searching I turned up these English links: Wikipedia on the relevant muscles with some exercises and this physiotherapy article with many details. The latter explicitly mentions unstable balancing as one exercise in a complex therapy setup.
jd_k20

"Established a useful new habit" (Background: I have a tendency to experience peak excitement about a new idea early on and then drop it entirely once the excitement wanes.) I have surprised myself by continuing to use HabitRPG for over a month now. I am very happy with the software; it really seems like it works for me.

"Established a useful new habit" I have been thinking for a while that I wish I was reading more philosophy, but I never quite got around to doing it. I finally decided that I would commit to just reading something -- I ... (read more)

jd_k00

In the same way that "product sales" was intended to refer to the result (income), "pollution" was intended to refer to the result (health problems, etc.). While one might think that some result is basically a certainty, the scope and degree of real problems is frequently uncertain. An entrepreneur who weighs potential public health risks does not seem any more difficult to imagine than one who weighs potential bankruptcy risks.

At any rate, pollution is merely an example; you can take any other example you find more suitable.

jd_k40
  • I finally registered on LessWrong and have slowly begun posting. I recognized that my reluctance to post was based on a feeling of intimidation. I have been overcoming the reluctance by consciously thinking, "I foresee long-term benefits to participating, and the potential disapproval of a bunch of [admittedly interesting] people on the internet hardly seems to counterbalance that benefit."

  • I registered an account with HabitRPG and began using it to combat (a) my tendency toward akrasia and (b) my tendency to simply forget about tasks that need

... (read more)
jd_k00

That seems right, and it also seems as though the opposite is sometimes right. If a company knows it can reap the benefits of operations (e.g., of product sales) without bearing the cost of those risks associated with its operations (e.g., of pollution), is this a case of risk-taking being oversupplied?

2RolfAndreassen
Pollution does not seem particularly well described by risk or risk-taking; it basically a certainty with industrial operations.
jd_k40

(Sorry for the delay in response.)

That is extremely helpful; it is just the kind of explanation I was looking for. I have begun working through some of the materials linked here, as well. Many thanks. Now that I am starting to piece the picture together, I need some time to mull over it and let my intuitions adjust to the ideas, but I may send you a message when I next get hung up on it.

jd_k00

It is the ontology angle in which I am most interested, but I am not convinced that I can understand the ontology on even a basic level without understanding the math.

jd_k00

I was looking for something more like the former.

I do not know calculus, but I am convinced that I need to for a variety of reasons, so I have begun working my way through the Khan Academy materials. I had intended to leave the quantum physics materials aside until that project was complete, but I was heartened by Eliezer's insistence that one need only know algebra to grasp the sequence. Perhaps I just need to do calculus first, then work through a few books/lectures. Do you think this to be the case?

9pragmatist
I don't recommend Eliezer's sequence as a first introduction to QM, at least not if you're interested in developing a reasonably deep understanding of the theory. If you want a minimal-math introduction, I think a better bet would be to check out the first few chapters of David Albert's Quantum Mechanics and Experience, illegally available in it's entirety here. I don't think Albert's book is an ideal introduction either, but I do think it does a better job than the sequence at getting the salient points across in simple language. Also, since you're interested in ontology, the latter half of Albert's book contains a pretty incisive analysis of various interpretations of QM (not just MWI). And here's an attempt at explaining quantum amplitudes: Let's start with classical configuration space, since you understand that. The possible states of a classical system are represented by individual points in its configuration space (well, technically, the configuration space doesn't give you the complete state of the system, because it leaves out information about velocities, but let's ignore that for now). In quantum mechanics, the configuration space looks just like classical configuration space, but its interpretation is very different. It's no longer true that the state of a quantum system is represented by an individual point in configuration space. The state of a quantum system is represented by a function on configuration space (the function has to satisfy certain other requirements in order to qualify as a bona fide representation of a quantum state, but ignore that detail also). So imagine your configuration space is only two-dimensional for now, and again imagine that we are only considering real-valued functions on configuration space. In that case, you could construct 3-D plots of the various functions that correspond to quantum states, with the x-y plane representing the configuration space and the z axis representing the value of the function. Here's an examp
jd_k20

(This was posted in the welcome thread, and I received a PM suggesting I post it here.)

I am looking for someone to help me with the Quantum Physics sequence. I have little background in physics and mathematics. For purposes of the sequence, you could probably consider me "intelligent but uninformed" or something like that.

To indicate the level on which I am having difficulties, take as an example the Configurations and Amplitude post.

  • I can do the algebra involved.
  • I found the articles linked in this comment helpful.
  • I understand the notion of c
... (read more)
0DanielLC
If you have specific questions to ask, I'd be happy to answer them. "Amplitude" just refers to a complex number corresponding to a given point in configuration space. The Schrödinger equation specifies how the field of these complex numbers evolves over time. The probability of being in a particular configuration is proportional to the square of this amplitude. Does that help?
1pragmatist
What sort of help are you looking for? Do you have specific questions (like, do you want someone to explain the notion of amplitude) or are you looking for general resources on QM? If the latter, then I highly recommend Leonard Susskind's lectures on quantum mechanics from his "Theoretical Minimum" series, available here. Susskind does assume that you know calculus. If you don't, then I suggest that you familiarize yourself with calculus before attempting a technical understanding of QM. If you'd rather read than watch, the lectures are also available in book form, here.
-1Shmi
I recommend that you first read popular or semi-popular books written by experts in the field (Eliezer isn't one). One of the more recent and highly praised semi-popular books which addresses many points Eliezer tried to get across is ScottAaronson's Quantum Computing since Democritus. Free lecture notes are also available, but not as complete. The book has a complexity-theoretic bend, but you can skip the parts you find too boring or too hard. Other classic semi-popular QM books are also available, including the venerable Feynman lectures. That one explains amplitudes very well, but is light on various ontologies, like MWI.
jd_k60

My name is Joshua. I am 29 years old. After lurking for a while, I have decided to begin participating.

I have little training in mathematics or computer science. Growing up, mathematics always came easy to me, but it was never interesting (probably because it was easy, in part). Accordingly, I completed a typical high school education in mathematics by my freshman year and promptly stopped. In college, the only course I took was college algebra, which I completed for the sake of university requirements. I now regret ending my mathematical education and hav... (read more)

2Squark
Hi Joshua, welcome! Regarding your quantum questions, you can post them to the open thread.