Magic card tricks

Interesting article in the New York Times today about how people to this day still do not know how magician David Berglass did his “Any Card At Any Number” trick. In this trick, a magician asks a person or two to name a card (e.g. Queen of Hearts) and a number (e.g. 37) and then in a variety of ways produce a deck where that card appears at that order in the deck. The supposed standard way to do the trick is for the magician to manipulate the cards in some way but Berglass does his trick by never touching the cards. He can even do the trick impromptu when you visit him by leading you to a deck of cards somewhere in the room or from his pocket that has the card in the correct place. Now, I have no idea how he or anyone does this trick but one way to do the trick is to use “full enumeration”, i.e. hide decks where every possibility is accounted for and then the trick is to remember which deck has that choice. So then the question is how many decks would you need? Well the minimal number of decks is 52 because a particular card could be in one of 52 positions. But how many more decks would you need? The answer is zero. 52 is all you need because for any particular arrangement of cards, each card is in one position. Then all you do is rotate all the cards by one, so the card in the first position is now in the second position for deck 2 and 52 moves to 1 and so on. What the magician can do is to then hide 52 decks and remember the order of each deck. In the article he picked the reporter’s card to within 1 but claimed he may only be able to do it to within 2. That means he’s hiding the decks in groups of 3 and 4 say and then points you to that location and lets you choose which deck.

Mosquito experiment concluded

It’s hard to see from the photo but when I checked my bucket after a week away, there were definitely a few mosquito larvae swimming around. There was also an impressive biofilm on the bottom of the bucket. It took less than a month for mosquitoes to breed in a newly formed pool of stagnant water. My son also noticed that a nearby flower pot with water only a few centimeters deep also had larvae. So the claims that mosquitos will breed in tiny amounts of stagnant water is true.

Mosquito update

It’s been about two weeks since I first set out my bucket, although I had to move it to a less obtrusive location. Still no signs of mosquito larvae, although judging from my bite frequency even with mosquito repellant, mosquito activity is still high in my garden. I see the occasional insect trapped (they are not really floating since at their size water is highly viscous) in the surface and there is a nice collection of plant debris at the bottom. The water level seems a little bit higher. It has rained at least once every two days since my first post although it has also been very hot so the input seems mostly balanced by the evaporative loss. I’m starting to believe that mosquitos have their prefered gestation grounds that they perpetually use and only exploit new locales when necessary.

The mosquito experiment

This month, Baltimore, along with much of the mid-Atlantic has been inundated with rain.  It was already the rainiest July on record as of last week. My yard has also been infested with mosquitos this summer. It was a very wet early summer, then it was extremely hot and dry for two weeks before the most recent deluge. Supposedly, mosquitos will breed in any amount of stagnant water. I thus decided to do an experiment to see how long it takes for a mosquito to find a suitable pool of water and go through a life cycle.  I started this on a whim by putting out some buckets a week ago.  Unfortunately, I wasn’t serious at first and didn’t record the exact date but I think it was Friday, July 20, which was right before the epic rains started. Below is a photo of my two buckets.  As you can see, one is filled to the brim and it is a pretty big bucket.  I haven’t measured the height yet but it looks like it is around 30 cm.  You can see a presumably dead mosquito floating in the orange bucket.  On the bottom, along with plant debris, are what I believe to be egg sacks, which look like 1 cm long beads on a string. The eggs are on the bottom and not floating, which is what I thought they were supposed to do. Maybe they are failures but we will see. There are also some other smaller insects and ants floating or trapped in the surface of the water.  I don’t see any larvae yet. The water was pretty clear as of Thursday of last week so it took about a week for the mosquitos to find the water.  That gives you a time window for how long you have before you should empty out any trapped water.  I plan to run this experiment until the larvae pupate and then I’ll end it before they become full adults.

The demise of Barnes and Noble

Near the end of the twentieth century, there was a battle between small bookstores and the big chains like Barnes and Noble and Borders, typified in the film You’ve Got Mail.  The chains won because they had lower prices, larger stocks, and served as mini-community centers where people liked to hang out. It was sad to see the independent bookstores die but the replacement was actually a nice addition to the neighborhood. The Barnes and Noble business model was to create attractive places to spend time, with play areas for children, a cafe with ample seating, and racks and racks of magazines. The idea was that the more time you spent there the more money you would spend and it worked for at least ten years. Yet, at the height of their dominance, the seeds of their destruction could be plainly seen. Amazon was growing even faster and a new shopping model was invented. People would spend time and browse in B and N and then go home to order the books on Amazon. The advent of the smartphone only quickened the demise because people could order directly from the store. The large and welcoming B and N store was a free sample service for Amazon. Borders is already gone and Barnes and Noble is on its last legs. The one I frequent will be closing this summer.

The loss of B and N will be a blow to many communities. It’s a particular favorite locale for retirees to congregate. I think this is a perfect example of a market failure. There is a clear demand for the product but no viable way to monetize it. However, there already is a model for providing the same service as B and N that has worked for a century and that is called a library. Libraries are still extremely popular and provide essential services to people, and particularly low income people. The Enoch Pratt Free Library in Baltimore has a line every morning before it opens for people scrambling to use the computers and access the internet. While libraries have been rapidly modernizing, with a relaxation of behavior rules and adding cafes, they still have short hours and do not provide the comforting atmosphere of B and N.

I see multiple paths forward. The first is that B and N goes under and maybe someone invents a new private model to replace it. Amazon may create book stores in its place that act more like showrooms for their products rather than profit making entities. The second is that a philanthropist will buy it and endow it as a nonprofit entity for the community much like Carnegie and other robber barons of the nineteenth century did with libraries. The third is that communities will start to take over the spaces and create a new type of library that is subsidized by tax payers and has the same hours and ambience of B and N.

Cecil and the hunter

Like many others, I was first outraged when I heard about the death of the beloved lion in Zimbabwe at the hands of a hunter from Minnesota. But I then quickly realized that I am in no position to judge the man. Over the past week, I have dined on salmon, chicken, pork, tuna, and beef. Just because I don’t go into the brush to kill an animal I consume doesn’t mean that I am not directly responsible for its demise. The only difference between me and a hunter is that I do not find any sport in the shooting of animals. There are nearly a hundred million cows at any given time in the US waiting to be slaughtered. Is the life of a cow not as valuable as that of a lion? It is no fault of the cow that she is not an iconic symbol like the lion. Fish are wild animals and we are hunting them to extinction. Tuna can live very long lives and are partially warm blooded. Sharks exhibit very complex behavior and have live births. I would suggest that the death of a big fish is no less tragic than the death of a big cat.

The unfortunate hunter paid a lot of money to go on what he thought was a legal hunt. The guides he hired may have misled him and broken the law but hunting lions in Zimbabwe is not a crime. Remember that this is a country that was near economic collapse just a decade ago and could use an infusion of hard currency. I have argued before that hunting may ironically be a way to preserve wildlife and habitat. The interests of hunters and environmentalists could be aligned. Regulated hunting could be an antidote to illegal poaching. If the hunter broke a law then he should be prosecuted. Otherwise, his choice of recreation is protected by the First Amendment of the US Constitution.

The demise of the American cappuccino

When I was a post doc at BU in the nineties, I used to go to a cafe on Commonwealth Ave just down the street from my office on Cummington Street. I don’t remember the name of the place but I do remember getting a cappuccino that looked something like this:Now, I usually get something that looks like this:   Instead of a light delicate layer of milk with a touch of foam floating on rich espresso, I get a lump of dry foam sitting on super acidic burnt quasi-espresso. How did this unfortunate circumstance occur? I’m not sure but I think it was because of Starbucks. Scaling up massively means you get what the average customer wants, or Starbucks thinks they want. This then sets a standard and other cafes have to follow suit because of consumer expectations. Also, making a real cappuccino takes training and a lot of practice and there is no way Starbucks could train enough baristas. Now, I’m not an anti-Starbucks person by any means. I think it is nice that there is always a fairly nice space with free wifi on every corner but I do miss getting a real cappuccino. I believe there is a real business opportunity out there for cafes to start offering better espresso drinks.

Unintended consequences

Here is a true story. A young man is trained to hit people as hard as possible and to react immediately to any provocation with unhindered aggression. He signs a 5 year contract for 35 million dollars to do this 16 times a year or more if he and his colleagues are very successful at doing it. One day he gets upset with his fiancée and strikes her in the head so hard that she is knocked unconscious in a public place. This creates a minor stir so the employer mandates that he must apologize and is prohibited from smashing into people for 2 of the 16 times he is scheduled to do so. The fiancée-now-spouse also refuses to press charges because she doesn’t want to jeopardize the 27 million over the next 3 years owed to the man. However, a video showing the incident is made public creating a huge uproar so the employer abruptly fires the man and condemns him since he now is no longer financially useful to the employer. The public now feels vindicated that such a despicable man is no longer employed and that domestic violence now is given the attention it deserves. However, the spouse is very unhappy because her comfortable lifestyle has just been pulled from right under her. Now, other spouses who live with violent but rich men will be even more silent about abuse because they fear losing their livelihoods too. If we really cared about victims of domestic violence, we would force the employer to set up a fund to ensure that spouses that come forward are compensated financially. We would also force them to support institutions that help the many more victims of domestic abuse who are not married to rich and famous people. This young man is probably an upstanding citizen most of the time. Now he is unemployed and potentially even angrier. He should not be thrown out onto the street but given a chance to redeem himself. The employers and the system who trained and groomed these young men need to look at themselves.

The morality of watching (American) football

The question in this week’s New York Times Ethicist column is whether it is wrong to watch football because of the inherent dangers to the players. The ethicist, Chuck Klosterman, says that it is ethical to watch football because the players made the decision to play freely with full knowledge of the risks. Although I think Klosterman has a valid point and I do not judge anyone who enjoys football, I have personally decided to forgo watching it. I simply could no longer stomach watching player after player going down with serious injuries each week. In Klosterman’s article, he goes on to say that even if football were the only livelihood the players had, we should still watch football so that they could have a livelihood. This is where I disagree. Aside from the fact that we shouldn’t have a society where the only chance to have a decent livelihood is through sports, football need not be that sport. If football did not exist, some other sport, including a modified safer football, would take its place. Soccer is the most popular sport in the rest of the world. Football exists in its current form because the fans support it. If that support moved to another sport, the players would move too.

Epic comeback

Well, I spoke too soon in my earlier post on the America’s Cup.  Oracle Team USA has since won 7 races in a row and now it is 8-8 in the best of 17 match (although they have already had 18 races). The final race to determine the winner is today. Check out the action here.  In the past, America’s Cup races had usually been best of 3 or best of 5 matches. In this new format, the races are much shorter, taking less than an hour rather than several, and they try to get in two a day if the weather permits. In the beginning New Zealand had the faster boat. They had already been racing for over a month in the challenger series and were just better than Oracle. However, the long format and some weather delays has given Oracle a chance to get up to speed and now they are definitely the faster boat. Yesterday, they flew by New Zealand on the upwind leg. The only chance New Zealand has to win today is if Oracle makes a mistake.

America’s Cup 2013

Today may be the last race for the America’s Cup yacht series between the US and New Zealand.   Here are the highlights from the last race.

It is a best of 17 series and New Zealand has 8 wins so today may be the last chance to watch these hundred million dollar multihull yachts fly around San Francisco harbour at close to 50 miles per hour.  All the races are posted on You Tube.

National Elk Refuge

Right outside of Jackson, Wyoming is the National Elk Refuge, which was established in 1912.  It is the wintering ground for a herd of ten thousand elk as well as eight hundred bison.  During winter, the elk come down from the mountains to the Jackson Hole valley where the snow is thinner so they can access grass more easily.  You can take a horse drawn sleigh right out to the herd with the Grand Tetons as the the backdrop. Here are some pictures.

Podcast update

Here’s whats on my iPod these days.  I definitely try to listen to the following three each week.  They are all about an hour so they fit into my drive home from work.

Quirks and Quarks:  Canadian Broadcasting Corporation’s weekly radio science show.  I used to listen to it as a child.  The first host was former scientist and current environmentalist David Suzuki.  It is now hosted by Bob McDonald.

The Science Show:  This is Australia’s long running radio science show hosted by the inimitable Robyn Williams

Radio Lab:  Possibly the most innovative thing ever on radio.  If you’ve never listened to radio lab, your missing out on a fantastic experience.

I sometimes listen to these.  The philosophy shows are half an hour or shorter while Econtalk is often longer than an hour so they are not as convenient to listen to on my drive.

Philosopher’s Zone: A show that is probably only viable in Australia, which has a vibrant philosophical community.  Host Alan Saunders is also a food expert.

Philosophy Bites: These are usually quite short but informative

Econtalk: Salon-like conversations between George Mason economist Russ Roberts and a guest covering a wide range of topics in economics and beyond  Although Roberts is a self-professed believer in markets his show is fairly well-balanced with different viewpoints.

I used to listen to these shows more but find myself dialing them up less for some reason these days:

All in the mind:  I find this half hour radio show a little too melodramatic at times but it can be interesting

The Naked Scientists:  This is a very popular radio show/podcast out of Cambridge, England.  I find it a little too flip at times and the hosts sometimes make mistakes.

In addition to these regular podcasts, I also listen to university lectures, mostly in philosophy, available on iTunes U.

The Genographic Project

National Geographic is conducting a research project (The Genographic Project) to analyze historical genome patterns  by sampling DNA from people all over the world. The main aim is to sample from various indigenous peoples from around the world but the public can participate as well. The website for the project is here.  There is a charge for a participation kit, which is used to defray the costs of the study.  You can have your mitochondrial DNA, which follows your maternal lineage, or if you are a male, the Y-chromosome, which follows your paternal line analyzed.  I  recently did the test for my Y-chromosome and I am a member of Haplogroup O with the M175 marker.  My earliest male ancestor emerged roughly 50,000 years ago in Africa and is the common ancestor of every non-African male alive today.  The man with the M175 marker emerged about 35,000 years ago during the ice age somewhere in Central or East Asia.  There were probably something like 100,000 Homo sapiens alive at that time.

Science Museums

When I was a child, I lived across the street from the Ontario Science Centre.  I loved the place and would go quite often.  When it first opened 40 years ago, the Science Centre was quite innovative in  its use of interactive exhibits and demonstrations as well as its architecture.  It drapes over  the side of a valley.  I still remember the excitement of riding down the escalators to the lowest levels where my favourite exhibits were.

I went back to the Science Centre this past weekend for the first time in several decades.  It has changed quite a bit but some of the old exhibits still exist in a room called the Science Arcade.  The architecture looks a little dated on the outside but holds up fairly well on the inside.  As I walked around, I wondered whether people actually learn anything at these museums.  There are lots of neat things to play with but do they actually get it.  An example is an exhibit of a Cartesian Diver, which consists of a small glass fish inside a cylinder of water.  The fish is partially filled with water.  The visitor pushes a button that pumps air into the cylinder and the fish sinks to the bottom.  However, there wasn’t a detailed explanation of how it works.  The write up basically said that as air is pumped into the cylinder the pressure rises and squeezes the air inside the fish.  It didn’t say explicitly that the fish had a hole in it so that water could move in and out and as the air in the fish was being squeezed by the water moving in due to the increased pressure, the fish became less buoyant and thus sank.  I saw a boy watch the fish sink and say, “how did that happen?”  Perhaps, the exhibit will spur his curiosity to learn more about it.

I believe the current idea of curators who design science museums and exhibits is that science museums should try to make science fun and cool.  Thus the exhibits need to been highly interactive and entertaining.   Maybe this is the right strategy and people do get a lot out of visiting science museums.  I really don’t know.  The National Academy of Sciences has a report, which I haven’t read, on this very issue.  I think having a science literate public is more important now than ever.   Do science museums play an important role in educating the public?

The Philosopher’s Zone

Last Thursday I had to drive from Baltimore to State College, PA for the 16th Congress of the US National Congress on Theoretical and Applied Mechanics to give a talk in one of the sessions.  I gave a condensed version of the kinetic theory of coupled oscillators talk I gave in Warwick last month.  The theme of the session was on recent advances in nonlinear dynamics so the topics were quite diverse.  I’m not sure my talk resonated with the audience.  The only question I received was how was this related to the NIH!

During the six hours of driving I did going back and forth, I listened to podcasts of the Australian radio show The Philosopher’s Zone.  This is a wonderful program hosted by Alan Saunders, who has a PhD in philosophy and is also a food expert.  Every show consists of Saunders talking to a guest, who is usually a philosopher but not always, about either a book she has recently written or some other philosophical topic.  The topics can range from the philosophy of Buffy the Vampire Slayer to Stoicism and everything in between.  Saunders has a knack for making complex philosophical ideas accessible and interesting.  In addition to The Philosopher’s Zone, I still regularly listen to Quirks and Quarks, The Science Show, Radio Lab, and The Naked Scientists.  I’ll also sneak in All in the Mind from time to time.

The neurobiology of sports performance

Now that we’re almost through the 2010 Winter Olympics in Vancouver, we have witnessed several examples of athletes excelling and underperforming. How an athlete responds to a high pressure situation could give interesting clues into the underlying neurobiology and evolutionary history of the brain. The brain has to operate under trade-offs. There is what Stephen Grossberg calls the plasticity-stability trade-off, where a system that learns must decide when to learn and when not to learn since learning involves overwriting previously learned patterns.   There is also the question of how much cognitive control should be exercised.  People talk about just letting their “muscle memory” takeover and go on “instinct” but what does that really mean neurobiologically?  Recent research has shown that a movement resulting from a reaction is faster than one from an intention.  These experiments found that people could hit buttons faster when they reacted to someone rather than when they initiated which  shows that more cognitive control can make you slower.

I think it is quite clear that some athletes rise to the occasion under high pressure situations while others wilt.  The question is why is there such variability.   Naively, it would seem that always performing under pressure should be a good thing.  The answer must be that rising to the occasion is not always optimal in an evolutionary sense.  Let’s imagine in paleolithic times that you’re in a stressful situation where you’re trying to catch your dinner or are running away from something that wants you for dinner.  That would be an analogous situation to a high pressure athletic event.  I think that there is not always an optimal strategy.  In some instances, you would want to simply run as fast as you can and being able to reach top performance would be helpful.  In other instances, it may be better to hesitate and come up with a plan before acting.

Darts and Diophantine equations

Darts is a popular spectator sport in the UK. I had access to cable television recently so I was able to watch a few games.  What I find interesting about professional darts is that the players must solve a Diophantine equation to win.  For those who know nothing of the game, it involves throwing a small pointed projectile at an enumerated target board that looks like this:

A dart that lands on a given sector on the board obtains that score.  The center circle of the board called the bulls eye is worth 50 points.  The ring around the bulls eye is worth 25 points.  The wedges are worth the score ascribed by the number on the perimeter.  However, if you land in the inner ring then you get triple the score of the wedge and if you land in the outer ring you get double the score.  Hence, the maximum number of points for one dart is the triple twenty worth 60 points.