Boston, when will you learn?

Ahhhhhhhhhhhh!!!!.

When are people (and by people I mean the Boston police) going to learn that lights do not imply bomb! In fact, I would bet that most bomb makers avoid putting flashy lights on their bombs.

One key point to notice near the bottom of the article - she did not go through security, she was just waiting around for her boyfriend and some guy at an information desk alerted the police. I do not blame the guy for alerting the police, but who considers deadly force on someone in a waiting area of an airport?

If you want to see the Scary device.

Also for those that don't get the back of the shirt, VI = 6 in roman numerals and 6 is the number for EECS at MIT.

Burn-In

Last night I read Burn-In: An Engineering Approach to the Design and Analysis of Burn-In Procedures. This only sort of counts since it was for work, and I'm quite certain no one reading this cares about burn-in so I'll keep the post short.

If you are for some reason interested in burn-in (a procedure for sorting out weaker than normal components and components damaged by manufacturing) it is a nice quick read. The funny thing about the book is it has pages and pages of statistics and reasonably advanced math to come up with some very precise formulas. But they are all based on knowing the reliability of components which is going to be a total guess (by orders of magnitude). One formula is actually proportional to e^C where C is a factor that is generally unknown. Anyway, I found it silly, but I'll stop now since no one cares.

Flatliners Game #3

Well this game the Flatliners earned their name. Once the score hit 19 to 0 in the first inning I stopped tracking it. Luckily the mercy rule does not kick in until the 5th inning or else I would not have gotten to play at all. After the first inning we actually did reasonably well. Not sure if we would have won if we didn't count the first inning but we would have done ok (of course the other team may have eased up a bit after the first inning - when the third baseman told one of our runners to go ahead and go for home it was a bit of a hint).

Personally, I did nothing special at bat - forced out at first both times. But I did get my first out. The batter hit the ball fairly high, straight up and I walked over and caught it. I feel like I should have charged to get under it and pushed the batter out of the way, but instead I sort of walked around him like I was worried about getting in his way.

I learned that you are supposed to hold a softball like a baseball (two fingers and the thumb) which was very useful. I also realized that my arm getting tired isn't the problem, but rather my attention dropping off. Along the same lines that I tend to remember stuff if I pay attention to begin with, I get a lot closer to my target if I take a moment to actually focus on throwing the ball.

Yom Kippur Hollywood Style

I am once again a proud owner of a passport - the chinese government gave it back without too much of a fight (although they did get $100 out of me). But now my passport has a picture of the great wall in it.

I took Friday off to get my passport. Once I got it back I had some time to kill. First I headed to Rodeo Drive. I'm sure it's exciting if you are looking to spend $100,000 on art or clothes or want to look at either of those. But just walking along the street was not as impressive as I expected. If I was going to walk around a fancy shopping area I would go to fashion island instead, although I don't usually walk around fancy shopping areas so not sure how much my opinion counts.

After that I still had some time so I went to the WB studio tour. That was fun. It was a bit weird because there was a group who drove up from dallas, a guy from philly, a girl from australia and I had just headed over to kill some time. When everyone else started taking pictures of everything I realized I probably should have brought a camera. I already realized that movies and TV are fake, but this really helped it sink in. When you look at the front of a house on TV the back of the house is probably the front of another house on the show. The NYC park where they play football in Friends is a tiny stretch of grass in a studio in LA. And of course practically everything is some setup in a sound stage. I did get to see Morpheus's car from the Matrix and the flying car from Harry Potter and I was sorted by the sorting hat (apparently there are 6 that they used, but the one that talks is all green just like a green screen), but I did not appreciate the house it put me in. In case you are curious, I think it is fairly obvious which house I think I should be in, and of course being in the same house as Harry would be good, and I actually don't mind going for pure power.

After the tour and through the next day it actually rained somewhat hard (ok everyone in Boston would laugh, but hard for LA). The craziest thing was over the course of Saturday I saw 9 cars broken down, some of them in the middle of the road. I have no idea why rain would cause cars to break down, it's not like they are special LA cars that aren't made for the rain. But it was way too many cars in one day to be a coincidence. I also got to see the LA river actually be a river (normally it is just a concrete thing that provides a good spot for filming car chases).

On Saturday I went to the Laugh Factory for services with Evan. This time we didn't show up ahead of time and ended up in the overflow room which was the first time I've ever watched the Rabbi on a giant flat screen. It was a bit silly watching on TV, although the room is setup as a lounge so it made for a much more comfortable services experience. Evan was fasting so I went with it. That was an experience I will not repeat soon (well, at least for another year). We were both so tired from not eating we spent the whole day watching TV (sometime someone is going to explain to me how not eating helps people concentrate on praying). For break the fast we went for a giant steak dinner. I was expecting to not be able to eat much, but I cleaned my plate.

Flatliners Game #2

Tonight the flatliners declared a "moral victory". It's not that we won, but the final score was something respectable like 9 to 6 and we made it through all 7 innings!

Apparently I need to work on my skills picking up the ball and tossing it back to the pitcher because I was demoted from catcher to every other inning catcher (I actually do, after a few innings my arm gets tired and the pitcher ends up running after the ball). Although, I did get on base twice. It's sort of crazy because I have no idea where my hits went - actually I can't remember the time between hitting the ball and being about 5 steps into running.

Rosh Hashanah Hollywood Style

On Rosh Hashanah I headed up to Hollywood to go to Rosh Hashanah services with Evan. Why Hollywood? Well, there is a free service at The Laugh Factory. I had no idea what to expect, but turned out to be a fairly standard service that just used the laugh factory as a room to hold it. I think it was the first time I had balcony seats for services. For the most part the crowd was what you would expect from services anywhere. Although no teenagers (I assume any family with kids around that age belong to a synagogue). Well, mostly what you would expect - the blond, plastic looking grandmother who sat next to me had a very large purse. After the purse made a sound she opened it for a moment and there was a small poodle in it. I was wondering if the service would include anything weird since it was in Hollywood. The only thing that was a bit different is the last song we sang was about peace and we sang it in both Hebrew and Arabic. They also had apples, honey and challah for everyone afterwards. Apparently someone sponsors the whole thing and requests that people in return make a charitable donation of their choosing.

After services we headed to the Chinese Consulate in downtown LA. I would describe it as somewhere between a post office and the DMV, but primarily in Chinese. When they finally called my number I handed the person my forms and passport, expecting her to look at them and give back the passport. She put a rubber band around them all, tossed them in a box, handed me a piece of paper and said come back Tuesday. So now the Chinese government has my passport until I drive back to LA (on a week day between 9 am and 3 pm with $100).

Next we headed to wait in the standby line for The Tonight Show. We got in, but sat in the very back next to the guy running the spot light. The guests were Terry Bradshaw, Marie Osmond, and Michael Buble. The show had some good jokes and it was interesting to see what happened off camera. The part I did not realize is that they go through in a single run and the breaks between segments are the same amount of time as commercial breaks. So while it is not actually live, it is taped like it is.

Probably the most unusual Rosh Hashanah I've ever had, although not nearly as odd as it could have been.

Flatliners Game 1

Well the flatliners (aren't we clever and funny....) just had our first softball game. I am bigger than one guy on the team we played against. I played catcher which in softball is somewhere around playing right field and sitting out. I did make it to first once since the guy playing first fumbled the ball for a moment.

I am proud to say we made it to the 5th inning before the score reached 18 to 3 and the mercy rule kicked it. Considering the other team had 14 runs in the first inning it actually lasted longer than expected.

Here's something I do think is clever and funny:

The after after life

For this blog post let's assume there is an after life. Then I wonder if people, souls, whatever, in the after life believe in an after after life and feel that they have to live their after life in a certain way to be rewarded in the after after life.

It might seem silly to think there would be an after after life since the after life lasts for eternity so what is this after after life to worry about. I'm thinking something along the lines that the number of seconds spent in the after life equals the number of integers (aleph_0), but the number of seconds in the after after life equals the number of real numbers (aleph_1). So you better be good during the after life because the after after life is infinitely longer.

Now you might argue that if the after life lasts an infinite amount of time how could there be something after it. Logically it doesn't work. Well, first of all, an after life doesn't work logically either (I can just hear someone saying "you can't prove there's nothing after eternity" and someone else groaning in frustration). Remember I'm only asking if people in the after life believe in an after after life, not if an after after life exists. Plus if there was an after life all of the believers would have really shown up the skeptics so people would probably be willing to believe just about anything. Every argument would be ended by "you said the same thing about the after life." Can you imagine hearing that line an infinite number of times?

Of course the logical extension is to ask about an after after after life, although that would require a lot of discussion of Godel and your choice of axioms (although people in the after after life who are into faith would love it because you truly could not prove it either way...). I figure I've got a while before I have to worry about the after after after life, so I'll stop here for now.

Excel

I was quite surprised by the following information so I feel the need to make a public service announcement about the stdev function in excel. I normally try to resist posting about math, but I think that lots of people use the stdev function.

If you ever use the stdev function in excel it may not be doing what you expect.

Typically the formula for the standard deviation of a set of points is
sqrt(sum((x-m)^2)/n)
where x is each point, m is the mean, and n is the number of points. This formula applies when you have all the points from a population. However, if you only have a sampling of points from a population then the correct formula is actually
sqrt(sum((x-m)^2)/(n-1))
I'll explain why below.

In excel the stdev function actually uses the n-1 formula. If you want the formula that divides by n the correct function is stdevp. Clearly picking the correct one only matters if you have a small number of points, since as n gets big the difference between the two becomes small. But if you are looking for the standard deviation of a few points it can make a big difference.

Standard deviation is about the distance of points from the mean. If you have the full population then you know the mean of the population and you know the distance from every point to the mean. So you have n distances that you are using. However, if you are only taking samples from a population then you do not know the mean of the population. So you create a mean from the points you have. But if you have two points then you really only have one distance, and you cut it in half by using the mean of your samples. So in this case you really have n-1 distances (by not having the population mean you have one less degree of freedom).

A quick check: If the entire population is one point then the mean equals that point and you divide by 1 so the standard deviation is zero. If you take one sample point from a larger population then the sample mean equals the one point so the numerator is zero and n-1 = 0 so it's 0/0 which is indeterminate which makes sense since if you only take a single sample you cannot estimate the standard deviation of the population.

I had never heard of the n-1 case before today and pieced together this explanation so don't trust it too much, but do be careful if using stdev with a small number of points.

The tortoise and the hare

I'm sure everyone remembers the tortoise and the hare and the lesson that slow and steady wins the race. I have no problem with the moral, in fact I've been making arguments along similar lines lately, which is what got me thinking about the story. But the fable never struck me quite right. I now realize it is because the moral and the story don't fit together. The moral is don't be an idiot or don't be an arrogant ass or... Slow and steady wins the race doesn't fit, because a hare that was actually determined to win would have gone fast and left the tortoise in the dust, and in fact if there was another rabbit in the race the one that loses in the story might have won since he would have taken it seriously and not bothered with the nap. Maybe the moral is actually to challenge yourself. If the fable was changed to where the rabbit had to take a nap because he was so tired from sprinting then the moral would fit.

That has been bothering me since childhood and I'm glad that we now have technology that allows me to broadcast that frustration to the world.

HP 2&3

I read HP 2&3. It seems like the series gets better as it goes. Similar to the movies I was much more into 3 than 1 or 2.

I have never been that convinced by the arguments that violence on TV causes people to be violent (maybe one of the trained neuroscientists reading this will actually know if that is true or not). But I have noticed that what I watch and read does impact what I eat. When I watch firefly I go in search of fruit - Kaylee just looks so happy when she has strawberries. When I was reading HP 3 I bought chocolate for the first time in months, maybe even a year - for some reason I pictured them eating standard milk chocolate, but I go for 70% or bust. Luckily all that BSG watching hasn't enticed me to start smoking or drink ambrosia (although they usually don't look that happy about either one).

For the firefly fans out there, who don't track xkcd (probably a null set, but anyway):
http://xkcd.com/311/

In case it is not clear from the rest of this post - I spent a lot of time inside reading HP and watching BSG over labor day weekend. Southern California let me down with a 100 degree weekend. Luckily it cooled back down by tonight for my company's softball team's second practice.