Comment author: Lumifer 02 December 2015 03:38:27PM 0 points [-]

What does "hear temperature" mean?

Comment author: solipsist 02 December 2015 06:09:39PM 2 points [-]

See my edit

Comment author: solipsist 02 December 2015 02:32:09PM *  2 points [-]

Why can I hear noise (white noise / pink noise / brown noise), but not hear temperatures?

EDIT FOR CLARIFICATION Air temperature is caused by air molecules moving randomly at high speed, white noise is caused by air molecules moving randomly at high speed, what's the difference? Why does white noise fill the room with sound instead of just raising the temperature slightly?

My hand-wavy-sounds-like-science-technobable guess is that temperature does fill the air with sound, but most of the energy of that sound is at far too high frequencies for my eardrums to detect (in part because my eardrums are emitting noise at a those frequencies). Maybe the average wavelength of thermal noise is roughly the mean free path length of the air molecules, so the average frequency of the noise is roughly 5 GHz. But I just making stuff up and really don't know.

Comment author: polymathwannabe 29 November 2015 03:59:23PM 0 points [-]

Those are suspiciously convenient examples. A more relevant comparison would be: Los Angeles is closer to Tijuana than London is to Paris.

Comment author: solipsist 29 November 2015 06:03:53PM *  0 points [-]

Well, I don't know. Some of the US is near Mexico, but most of it isn't. In Europe the farthest you can get from a border to foreign speaking country is perhaps southern Italy. The four US states which border Mexico are each bigger than Italy. Germany is a bigish country in Europe area-wise, but it's less than 3.7% the size of the US. The Mercator projection makes an optical illusion -- the US is huge.

Comment author: ChristianKl 26 November 2015 10:57:42PM 3 points [-]

I don't understand why facebook messes up the language issue so strongly. It seems like the American's at facebook quarters just don't care about bilinguals.

Comment author: solipsist 29 November 2015 06:57:00AM 2 points [-]

Yeah, your explanation sounds absolutely correct. But before you think "silly monoglot Americans", remember that London is closer to Istanbul than New York is to Mexico. Countries where people don't mostly speak English are thousands of kilometers away from most Americans.

Comment author: Vaniver 23 November 2015 06:57:51PM *  13 points [-]

Short version: try something like Vanguard's online recommendation, or check out Wealthfront or Betterment. Probably you'll just end up buying VTSMX.

Long version: The basic argument for index funds over individual stocks is that you think that a <broad class> is going to outperform a <narrow subclass> because of general economic growth and reduced risk through pooling. So if you apply the same logic to index funds, what that argues is that you should find the index fund that covers the largest possible pool.

But it also becomes obvious that this logic only stretches so far--one might think that meta-indexing requires having a stock index fund and a bond index fund that are both held in proportion to the total value of stocks and bonds. So let's start looking at the factors that push in the opposite direction.

First, historically stocks have returned more than bonds long-term, with higher variability. It makes sense to balance your holdings based on your time and risk preferences, rather than the total market's time and risk preferences. (If you're young, preferentially own stocks.)

As well, you might live in the US, for example, and find it more legally convenient to own US stocks than international stocks. The corresponding fund is VTSMX, for the total US stock market. If you want the global fund, it's VTWSX.

You might have beliefs about small caps and large caps, or sectors, and so on and so on. One mistake to avoid here is saying "well, I have three options, so clearly I should put a third of my money into each option," especially because many of these options contain each other--the global fund mentioned earlier is also a US fund, because the US is part of the globe.

Comment author: solipsist 25 November 2015 12:50:38PM 3 points [-]

Asset allocation (what portion of your money is in stocks and bonds) is very important, depends on your age, and will get out of whack unless you rebalance. So use a Vanguard Target Retirement Date fund.

Comment author: IlyaShpitser 16 November 2015 06:33:57PM *  2 points [-]

I don't think any one person understands the Linux kernel anymore. It's just too big. Same with modern CPUs.

Comment author: solipsist 17 November 2015 01:13:31PM 4 points [-]

Although the Linux kernel and modern CPUs are piecewise-understandable, whereas neural networks are not.

Comment author: cousin_it 16 November 2015 02:23:04PM *  9 points [-]

I've been hearing about all this amazing stuff done with recurrent neural networks, convolutional neural networks, random forests, etc. The problem is that it feels like voodoo to me. "I've trained my program to generate convincing looking C code! It gets the indentation right, but the variable use is a bit off. Isn't that cool?" I'm not sure, it sounds like you don't understand what your program is doing. That's pretty much why I'm not studying machine learning right now. What do you think?

Comment author: solipsist 16 November 2015 03:58:59PM 1 point [-]

Is it for reasons similar to the Strawman Chompsky view in this essay by Peter Norvig?

Comment author: solipsist 16 November 2015 03:27:13PM *  0 points [-]

It sounds like you do not understand what your experiments are doing. That's pretty much why I'm not studying electromagnetism.

-- Letter from James Clerk Maxwell to Michael Faraday, in the setup of a Steam Punk universe I just now invented

Comment author: solipsist 16 November 2015 03:45:11PM *  2 points [-]

Here's how I read your question.

  1. Many machine learning techniques work, but in ways we don't really understand.
  2. If (1), I shouldn't study machine learning

I agree with (1). Could you explain (2)? Is it that you would want to use neural networks etc. to gain insight about other concrete problems, and question their usefulness as a tool in that regard? Is it that you would not like to use a magical back box as part of a production system?

EDIT I'm using "machine learning" here to mean the sort of fuzzy blackbox techniques that don't have easy interpretations, not techniques like logistic regression where it is clearer what they do

Comment author: cousin_it 16 November 2015 02:23:04PM *  9 points [-]

I've been hearing about all this amazing stuff done with recurrent neural networks, convolutional neural networks, random forests, etc. The problem is that it feels like voodoo to me. "I've trained my program to generate convincing looking C code! It gets the indentation right, but the variable use is a bit off. Isn't that cool?" I'm not sure, it sounds like you don't understand what your program is doing. That's pretty much why I'm not studying machine learning right now. What do you think?

Comment author: solipsist 16 November 2015 03:27:13PM *  0 points [-]

It sounds like you do not understand what your experiments are doing. That's pretty much why I'm not studying electromagnetism.

-- Letter from James Clerk Maxwell to Michael Faraday, in the setup of a Steam Punk universe I just now invented

Comment author: WhyAsk 05 November 2015 10:22:40PM 6 points [-]

"A “pink flamingo” is a term recently coined by Frank Hoffman to describe predictable but ignored events that can yield disastrous results. Hoffman argues that these situations are fully visible, but almost entirely ignored by policymakers. "

Why are they ignoring this?

Comment author: solipsist 16 November 2015 03:39:31AM *  1 point [-]

The Snowden / Manning leaks (from what I've heard) suggest this issue is the third or forth priority of US intelligence organizations. One presumes that the US intelligence organizations do not consider it in their interests to advertise this fact.

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