Sunday, June 27, 2010

Apple #466: Making Decisions When You're Tired

For some time now, I've been aware of the fact that when I'm tired, I have a harder time making decisions.

In the grocery store, for example, whether to buy things that are cheap/bad for me or expensive/good for me is always an issue, but when I'm tired, this can become an almost impassable choice.  I stand there staring at the options until I wind up deciding on the basis of something stupid or irrelevant -- it's the loaf of bread I happen to have in my hand when I give up trying to make a decision.  I like poppy seeds and this muffin looks like it has more poppy seeds in it.  I first ate that cereal at a friend's house when I was a kid and that was a good day then, so I'll buy it now.  Or I walk away from the whole thing altogether.

I've noticed this sort of thing happening often enough that I, in true Apple Lady fashion, have gotten curious about it.  I wondered, is there a set of steps your brain goes through on the way toward making a decision?  And does being tired somehow keep your brain from getting to one or more of those steps?  Is there something in particular that's getting derailed, and is there some way I can get my brain back on the rails even when I am tired?

I've been doing quite a bit of reading on this for a while now, and I found all of it really fascinating.  Of course, since it's the brain that's involved and the brain is a complicated piece of machinery, the answers are not simple 1, 2, 3.  But I'll try to break down what I've learned into simple enough bits that you'll be able to take them in.

The Brain Is Complicated
  • The first thing to know is, your brain is not like a department store: one room for shoes, one room for memories, one room for anger, a room for decision-making, a room for shoes, and so on.  But it is very tempting to imagine it this way.

In the 19th century, phrenology heads like this one were very popular among scientists.  They drew sections on heads and labeled them with all sorts of attributes or emotions because they believed that those emotions were handled or produced by that particular part of the brain.
(Photo from Hill Gallery folk art)

  • There's still a kind of phrenology at work today.  Neurologists will hook subjects' brains up to various imaging machinery and they have the subjects perform certain tasks.  They watch a small portion of the brain to see whether it "lights up," or is especially active during this task.  This research gets published in the popular media as, "Left side of brain controls speech!" or "Right side of brain determines whether you're religious!"
  • In truth, the brain is an extraordinarily complex web of chemical and neurological interactions. In nearly every brain activity, there are several regions or systems involved to some degree or other.  Pinning a particular mental function down to one place or one chemical exchange isn't realistic.

It's the Prefrontal Cortex, Stupid -- But Wait, There's More
    • So it is misleading to say what nearly everybody says about decision-making, which is that it's handled by the prefrontal cortex.  That's generally true, but it's also more complicated than that.

    The prefrontal cortex  is the hunk at the front of the brain that starts above your forehead and goes back to about the middle of your head. This is where a lot of the activity surrounding decision-making takes place, but it's not the only part of your brain involved.
    (Diagram from Brian Explorer)

    • The prefrontal cortex is not the only place involved in decision-making, but to make things easier for a second, let's say that it is.  I'll come back to the other areas later.

    Seven Is My Limit!
    • While most of your brain handles an incredible amount of information and performs a tons of tasks at lightning speeds, the prefrontal cortex is a bit weak by comparison.  Researchers have found that the prefrontal cortex can handle only about  seven pieces of input toward a decision at one time.  Any more than that and it gets overloaded and it spins and spins, or it shuts down, or it otherwise can't reach a decision.
    •  Let me put this in real-life terms.
    • Let's say Wanda is in a store, holding a shirt sleeve with the price tag  dangling off it, trying to decide whether or not to buy the shirt. 
      • She's taking in the visual cues of the shirt and the price tag, and  probably other sensory input as well. She's feeling the texture of the fabric, the store is playing music,  someone just walked by wearing perfume, and there's a guy in the back of the  store shouting into his cell phone, so she's hearing and feeling and smelling all of these things. 
      • She's also considering how this shirt looked when she tried it  on, she's trying to remember how much  money is in her bank account, and how well did shirts like it hold up after she washed them several  times, she's wondering does she even like the color of this shirt, does her husband like  this color, does she have other things at home that she can wear it  with, and so on.

    The blue shirt. A black hole of indecision for Wanda.
    (It's by Oasis, and it sells for £14.40 on

      • Not counting the guy shouting into his cell phone, the perfume, and the   music, Wanda is trying to negotiate six factors in that shirt-buying  decision.  That's not an especially high number, but for the prefrontal cortex,  it's a lot.  If I were to add one more factor to that decision, Wanda's  prefrontal cortex would get overloaded, and that's when she would  probably walk away from the whole thing. 
      • Or she might make a decision whether to buy or not on the basis of whatever thought or emotional response out of all of those that stands up and demands the most attention.
        • Maybe the color of the shirt reminds her of the color her room used to be when she was a little girl, and that's a happy memory for her, so she buys the shirt.
        • Maybe the music that the store is playing is something she likes and is in some way soothing to her.  She decides she doesn't need to worry about money all that much, so what the heck, she'll buy the shirt.
        • Maybe the guy shouting into his cell phone gets even louder and trips her annoyance limit, so she lets go of the shirt sleeve and walks out of the store without buying the shirt.

      Logic + Emotions or Instincts = Decision
      • Even though our powers of logic and reason and analysis may be engaged, our emotions and  memories get called into the act, too.  Those emotions and memories and what some researchers call "instinctual" responses come from other parts of the brain than the prefrontal cortex.

      The colored sections are collectively called the limbic system. Each of these elements has something to do with our emotions or instinctual responses. The hypothalamus deals with basics like breathing, hunger, thirst, heart rate, body temperature, as well as sexual response, anger, and aggression. The pituitary gland is where hormones are produced that regulate the  stuff that the hypothalamus wants controlled.  The amygdala is also involved in sexual response, anger, aggression. The hippocampus is where short-term memories get converted to long-term memories.
      (Diagram from Dr. C. George Boeree)

      • Those "emotional centers" in the limbic system are all connected to the prefrontal cortex. (I'll talk about those connections later.)  But these areas of the brain also get involved, along with the prefrontal cortex, in decision-making.
      • We have a sort of prejudice against emotions when it comes to decision-making.  We like to think that the best decision-making is done completely logically and rationally.  But our brains don't -- and in fact, can't -- work that way.
      • People who lack emotions because of brain injuries have been studied for some time, and the research continues to find that they   often have a very difficult time making decisions.  Even decisions as simple as whether to use a black pen or a red pen, they just can't process it. 
      • This is because, when faced with a decision, in addition to calling upon facts, the brain  also calls upon memories and emotions of similar experiences from the  past, and it brings all that into account. People who can't access their emotions can't bring those to bear on decisions, and they simply can't make a choice.
      • In truth, our emotions are very much involved in nearly every decision we make.  

      We tend to assume that we don't want emotions involved in decision-making.  But in real life, we need and want them involved.  Mr. Spock might be an  entertaining concept on television, but in real  life, he would probably  be annoying, if not dangerous.
      (Photo from ugeene's  Nerd Zone)

      Emotions: Hey, They're Not So Bad
      • Let me talk about terminology for a second.  Some researchers have studied emotions versus logic, others have studied what  they call "instinctual" responses or gut reactions versus analytical  thinking, or they have compared the influence of long-term memory versus short-term memorization, those sorts  of pairs.  Even though each of those pairs involves slightly different activities, I'm going to simplify them for the sake of this  discussion and call all the emotional/memory/gut reaction stuff the instinctual response.  All the analytical cognitive reasoning stuff I'm going to call logic.
      • To demonstrate how often our instinctual response gets involved in decision-making, here is a math problem one researcher uses to reveal how readily this happen:
        • A bat and ball together cost $1.10.  The bat costs $1 more than the ball.  How much does the ball cost?
        • Most people answer right away: 10 cents.
        • That seems like it should be the correct answer, but it is not.  If the ball costs 10 cents, the bat would cost $1 more than that, or $1.10, which would bring the total to $1.20.
        • The correct answer is found with a bit of algebra.
            • ball + ball + $1 = $1.10
            • 2x ball = $0.10
            • ball = $0.05
      • Most of us don't stop to work out the problem step by step.  We rely on the number of times we've had to make change at the store, or other scenarios where we've wound up with simple answers like $1, and that's how we arrive at our answer -- and we get there very quickly, too.  
      • Those of us who deal with more complicated math problems on a more frequent basis probably saw the trick in that problem much sooner, knew there was more to it than met the eye, and arrived at the correct answer -- and got there quickly, as well. 
      • In fact, chances are that those who are more "mathy" than the rest of us didn't actually take the time to do the algebra problem step by step, but rather had done enough problems like it to know how this one would turn out, too. Even for those who have what we would generally call a more logical mind, simply because their brains do math problems more often, they still probably would have engaged that instinctual response to arrive at an answer.
      • We tend to demonize emotions and say that when the emotions get involved, we make poor decisions.  But this is a great example of why we're erroneous in saying that.  The "mathy" people would have relied on their instinctual response to arrive at the answer to the bat & ball problem, while the less mathy among us did the same thing.  The difference is not that the mathy people didn't engage their instinctual center but rather that the mathy people have a lot more experience with this type of problem, and that's why they got the right answer.
      • In fact, sometimes we make better  decisions because our emotions are involved. One of the occasions when you want your instinctual response/memory center to be the most  involved is, seemingly paradoxically, when you've  done a task hundreds or thousands of times.  
        • People who have played thousands of games of chess, for example, remember the consequences of the moves they made in  past games and they've linked those memories to success (positive  emotion) or failure (negative emotion).  The chess experts who are  making moves at lightning speed are rapidly rejecting other possible and  less favorable moves based on the hundreds of occasions those moves  have turned out badly.  Because of their memories and emotional  experiences, they can rule out a multitude of options and thus make  decisions very quickly.  They don't have to "think;" they can act on  their "gut instinct."
      • So let's go back to Wanda in the store holding the shirt sleeve.  Her prefrontal cortex is trying to manage all sorts of logical aspects to the question.  But in the end, her instinctual response center steps in and makes the decision for her.  The color reminds me of something nice; let's get the shirt.  That guy is annoying the crap out of me; let's get out of here.  If that instinctual response center didn't step in, she'd probably still be standing there holding the dang shirt sleeve.

      Context Is Everything
      • Even if you don't believe me that your emotions are involved in decision-making, even if you did that math problem step by step and you are still convinced that you are always logical and rational about all your decisions, I've got news for you.  Your brain takes short-cuts.  Whether you're aware of it or not.  All the time.
      • Perhaps the biggest short-cut your brain takes in decision-making is to rely on context.  
      • Here's one really good example of that:
        • People were put in one of two rooms. One room had a chocolate bar over in the corner, and the other room had a can of Spam over in the corner.  The chocolate and the Spam were both some distance away, they were wrapped up, not emitting any scents or anything.  Each person, once seated in his or her given room, was given a bag of chips to eat.  Everybody got exactly the same kind of chips.
        • The people who ate the chips in the room with the chocolate bar said they liked the chips a whole lot more than the people who ate the chips in the room with the can of Spam.
        • There was no difference in the chips.  The subjects weren't influenced by the chocolate or the Spam through any other route than visually, and yet they were significantly influenced by the visual proximity of those items.

      Chocolate or Spam?  Don't need to think much about that choice.
      (Hershey bar photo from Quia. Spam photo from The Geek Whisperer)

        •  Here's another example of how context influences our decisions.  This time, the emotions get involved in ways we'd rather not admit.
          • People were given dice and a small amount of money to gamble with. 
          • First they were told they would keep 40% of the money if they didn't gamble, and then they were given the opportunity to roll the dice.  Next they were told they would lose 60% of the money if they didn't gamble, and they were given the opportunity to roll the dice. The outcomes are exactly the same, but they are worded differently.
          • When people were told they would lose more if they didn't gamble, they rolled the dice far more often.
          • Some of the subjects even said they knew the odds were the same, yet they just couldn't help themselves.  This is because how the situation was framed (the context) triggered people's fears of losing resources.

          This guy, a behavioral economist named Dan Ariely, has more examples about how context influences our decisions.  The first 2:25 or so is a bit of a preamble, but then he gets into specific examples.  It's about a 15 minute talk, but he's engaging in the way he presents his material, he's got a really good point about why we should care about all this, and I highly recommend it.

          •  What his talk comes down to is that we rely on things like context and optical illusions because making decisions is hard.

           What Did the Doctor Say?
          • Another short-cut our brains take is to rely on experts to help us out.  If we're faced with a complex set of choices, we sit there and churn over the choices to try to arrive at a decision on our own.  But if we're told that such-and-such an expert has advised that this choice is the best one, our brains churn over the problem for a significantly shorter amount of time, and we tend to make the same choice as what the expert has recommended.
            • This is why you see commercials that feature someone in a white coat who is or looks like a doctor. Movie and TV stars in commercials, same thing. If we think that someone we respect or look up to for any reason has thought out the problem for us already, we tend to stop thinking and do what the "expert" recommends. Scary, but true.

            If someone wearing a white coat like this guy is says we should do something, most of us stop thinking and do what he says.
            (This guy actually is a doctor.  He's Dr. Lawrence Raisz, and he's an expert in bone health at the New England Musculoskeletal Institute. Photo from U of CT Health Center)

              • Another version of this is we get out our cell phones and call our friends, our spouses, our parents, and ask, "Do I get the tattoo or not?"
              • When the decisions are about things we care about, things that are complex issues, things that have lots of facets and contingencies and maybes, the decisions get even harder.  Our prefrontal cortex gets overwhelmed and we turn to things like context and experts to help us make the choice.

              Add a Dose of Pleasure
              • Okay, so you're getting the point that decision-making is hard, lots of things are involved, our brains turn to other inputs to make decisions more easily.  It's already complicated to begin with.  But there is (at least) one more element to the decision-making process, and that's pleasure.
              • Dopamine is a neurotransmitter, a chemical that carries with it an electrical impulse from one neuron in the brain to another. It travels from the hypothalamus and pituitary gland (part of the limbic/emotional center, remember), and it follows pathways that lead to our old friend the prefrontal cortex.

              The path that dopamine takes from its home in the ventral tegmental area (VTA), which is near the limbic system, up to the prefrontal cortex.
              (Diagram from the NIH's National Institute on Drug Abuse)

                • Dopamine has a lot of different jobs.  One of them is to help make our motor muscle movements smooth.  People with Parkinson's Disease have a deficiency of dopamine.
                • Another, more famous job of dopamine is to stimulate our "pleasure centers" which are more or less in the brain stem.  When we do something our brain interprets as good, dopamine is released, it stimulates that reward center in the brain stem, we feel a sense of enjoyment, and so we want to do that good thing again.
                • Similarly, when we make a decision that our brain interprets as good, dopamine is released, and we feel a sense of pleasure with the decision we've made.  So we'll be more likely to make decisions like it again in the future. 
                • Our brains in effect train us to make decisions, perform tasks, and repeat the behavior based on whether or not we've gotten rewarded.
                  • Three researchers, Montague, Dayan, and Schultz, spent 15 years studying how monkeys make choices.
                  • They connected the monkeys to electrodes that tracked dopamine levels in their brains, and the monkeys were trained to push a bunch of buttons in a particular sequence.  If they got the sequence right, they would get a squirt of juice -- a reward.
                  • They discovered a ton of things in their 15 years with the monkeys, but one of the main things they found was that before the monkeys got their reward, the dopamine neurons started to fire.  The monkeys had learned to expect that when they got the light code right, they'd get the reward, which triggered the pleasure.  The monkeys saw a pattern and connected getting the light code correct with pleasure.
                • What this means for us is that, like the monkeys with their juice, we are constantly looking for patterns of behavior that will get us a reward.  Last time I bought a shirt like this, that turned out to be a really good experience, so I'm going to buy another shirt like it.  Or, last time I went into that store, there was a guy in there talking on his cell phone really loudly and that was annoying, so I'm not going to go in there again.  We do this kind of thing all the time.
                • Addicts are an extreme example of how we all respond to patterns and rewards.  A lot of addicts talk about "triggers."  When an alcoholic hears the pffft of someone opening a can of beer, they'll start to salivate and want a drink.  Heroin addicts will start to want a fix if they see a needle or a belt or other equipment associated with shooting up.  Their brains have been trained to expect a reward in response to certain patterns of behavior.  Once part of that pattern is set in motion, their brains are already getting the dopamine ready.

                I bet you're already anticipating the motion of levering open the bottle cap, the resultant pffft spray, perhaps the sound and the smell of it. Maybe you've also noticed the beads of moisture on the bottle. Thirsty yet?  That's your hypothalamus and the dopamine getting you ready for something to drink.
                (Photo from Channel 4 in Belfast)

                  • Another aspect of this is true, too.  I'll let this guy named Jonah Lehrer, who's written a whole book about how the brain makes decisions, talk about the relationship between dopamine and patterns and addiction.

                  I talked to a woman named Ann Klinestiver, who was diagnosed with  Parkinson's in 1998, and, like many Parkinsonian  patients, she was put on a drug called a Dopamine agonist. And the purpose of  these drugs is to increase the amount of Dopamine in the brain.

                  One of the common side effects of these drugs is gambling  compulsions. Some studies estimate that as many as 10 to 15 percent of  patients on these drugs develop some sort of gambling problem. And in  the case of Ann, it's a very sad story. It really ruined her life. She  lost her entire life savings, more than $250,000. Her husband left her.

                  She  had a compulsion for slot machines. She would spend 18 hours at a time  putting quarters into one-armed bandits. And I think one of the reasons  slot machines and games of chance in general are so addictive is because  they hijack the Dopamine system. 

                  The Dopamine system's great at finding patterns. It can find the pattern that predicts a squirt of juice, but it's terrible at dealing with random systems. It's terrible at dealing with that random-number generator inside the slot machine because it generates a consistently surprising reward.

                  Even though there's no pattern to find, we can't help but search for a pattern.

                  When Ann got a reward from a slot machine, when she got some coins in return, the end result was this surge of emotion, this surge of Dopamine that signaled something really good had happened. And so she became transfixed by this random system.

                  Her brain was literally trying to figure it out, in essence. It was trying to find the pattern that predicted the clanging coins, that predicted when she would win in the casino. But the reality, of course, is that there's no pattern to be found. You know that no matter how hard her Dopamine neurons tried, they would never find the sequence of events that predicted the payout. But because they were so saturated with neurotransmitter because she was on this Dopamine agonist drug, she simply couldn't walk away.

                  Jonah Lehrer talks about this topic and more of the elements of decision-making in his book How We Decide, which you can order from Amazon for about $10.

                  Besides All That, You're Tired

                  Now, add to all of this the fact that we're tired.  We haven't had enough sleep the night before.  Or it's the end of a long day and we've already had to make a ton of decisions.
                  • Research has shown that the act of making decisions themselves tires us out.
                    • This has been demonstrated, time and again, on voting ballots.  Say there's a complicated proposition up for a vote.  On some ballots, it's positioned at the top where voters are "fresh" when they first read it.  On others, it's positioned farther down.  On still others, it's at the end.  
                    •  The farther down the ballot, the more people voted no, and the more people abstained from voting on it altogether. By the time they got to the issue, they were tired of having to make so many choices, and they simply didn't have enough left in the mental tank to grapple with the complicated concepts.
                    • This is why nearly every single ballot puts those propositions right up front.
                  • Not only does decision-making tire us out, some decisions wear us out more than others.
                    • Easiest: someone else has made the choice and all you have to do is implement it.  If the person in the white coat has told you to swallow the pill and you believe the person in the white coat, all you have to do is swallow the pill.
                    • A little harder: to think about the options you've been given and indicate some that you like better.  This is like answering the question, "What are some of the movies you've seen lately that you've liked?" as opposed to answering the question, "What's your all-time favorite movie?"
                    • Hardest: to choose one thing from among a lot of options.  This, my friends, is a trip to the grocery store.
                  • No wonder I have trouble making decisions when I'm tired at the grocery store.
                  • It's no mistake, by the way, that all those guilty pleasures are right next to the check-out stand.  Those are called "impulse buys" in the retail business.  What they're counting on is that you'll already be so fatigued by the other decisions you've had to make in the rest of the store that you'll be too tired to resist the candy bars and the National Enquirer and the mini-crossword puzzle book, and you'll also want to reward yourself for what you've just been through.

                  What It Comes Down To

                  So now that we know all of this, what do we do?  We can't exactly reconfigure our brains to operate differently.  Mainly, the people who talk about this all say that we can be aware of our limitations, understand how our brain works, and not get frustrated when it's not working at the speed or agility we'd like.  Recognize that it's already done a ton of stuff for us today, and be patient.

                  Well, that's all very nice, but for me, it doesn't really help when I'm standing there with the loaf of bread in my hand, or when Wanda is standing there holding onto that danged shirt sleeve.  So here's what I've done or tried in the past few days since I read about all this stuff. And it seems to help.
                  • Get more sleep.  I hate this suggestion, but I have to say it because it's true.  Sleep is like food to your brain.  It needs it.
                  • Simplify.  If you find yourself adding more criteria to a decision you're already having trouble making, stop.  That's only going to make it harder for you to decide. 
                  • Eliminate some of the factors involved in the decision, if you can.  Get rid of the elements you care less about, or focus only on the one that's most important to you.  If you're Wanda standing there holding the shirt, maybe you care most about how much money you'll have to spend.  Maybe you care most about how it looked on you when you tried it on.  Maybe you care most about whether your spouse will think you look hot in it.  You might still make an emotional decision, but at least it'll be most in line with what you want after you've left the store.
                  • Give your brain a break.  Put down the loaf of bread, walk over to the  floral aisle or someplace where you can just look at pretty stuff but not be required to make any decisions.  Then go back to the bread aisle,  and probably the choice will seem obvious.
                  • Time Those Decisions. If you know you're tired, don't put yourself in a situation where you'll have to make lots of choices.  Go to the grocery store earlier in the day.  Don't get into a huge conversation with your spouse about whether to buy that house when you're about to go to bed. Intersperse thorny-decision-making times with activities that are fun and less mentally taxing.  Your prefrontal cortex -- and your dopamine receptors! -- will thank you. 
                  • Actually a couple researchers did have one big-picture statement to make.  They said that since nearly everything about the brain links up to that reward system, which is governed by the central limbic system, we're all ultimately pawns of those most basic impulses: food and sex.  Even the most high-falutin' and apparently selfless of our values, they say, can ultimately be traced back to those basics.  So if you're having trouble choosing something, ask yourself, will it get me more food?  Will it get me more sex?  Supposedly, since that's what your brain is really grappling with anyway, getting straight to that point might help you make a decision more quickly and to your greater satisfaction.

                    According to some researchers, this is all we really want in the end: food and sex.  In fact, just thinking about either of these two things -- particularly if the food is chocolate -- can reduce anxiety, improve mood, and even help people cope with physical pain.  Man, that's powerful stuff.
                    (Photo from Neuromarketing)

                    Dan Vergano, Study: Emotion rules the brain's decisions, USA Today, August 6, 2006
                    Dermot McGrath, Where the Brain Makes Decisions, Wired, April 22, 2002
                    Elizabeth Landau, Why your brain can't always make good decisions,, 1/12/2009
                    Dr. C. George Boeree, General Psychology, The Emotional Nervous System
                    Jonah Lehrer: Passions Of The Brain, interview with Terry Gross, NPR, March 2, 2009
                    Jonah Lehrer, A New State of Mind, Seed Magazine, August 8, 2008 
                    Lisa Bendele, Professor explains how we make decisions, The Daily Princetonian, September 21, 2007
                    On Amir, Tough Choices: How Making Decisions Tires Your Brain, Scientific American, July 22, 2008 
                    Kathleen D. Vohs, et al., "Making choices imapirs self-control" (Abstract), Journal of Personality and Social Psychology, January 25, 2010
                    Kara Rogers, Neuroeconomics: Studying How We Make Decisions, Encyclopedia Britannica Blog, July 21, 2009
                    Augenblick and Nicholson, Choice Fatigue: The Effect of Making Previous Choices on Decision Making, Stanford University Department of Economics, April 2009
                    Lee Dye, How the Brain Makes Quick Decisions,, February 19, 2009
                    The Schizophrenia Homepage, New Research Provides Brain Clue to Making Best Choices for Self, March 13, 1997
          , Researchers find where brain learns to make decisions, 2005
          , Dopamine, January 2007

                    Friday, June 25, 2010

                    Apple #465: Library of Congress

                    I'm working on a big ol' entry that I was hoping to have finished for you tonight, but it's not going to happen.  So I thought I'd find some quick facts about an institution that is related in a way to this here Daily Apple: a repository for an insane amount of knowledge, the Library of Congress.

                    • The mission of the Library of Congress is to sustain and preserve a universal collection of knowledge and creativity for future generations.  That's an enormous goal.  So naturally, the Library of Congress will itself be enormous.
                    • The Library currently holds around 145 million items -- books, photographs, maps, audio recordings, sheet music, manuscripts. These items occupy 745 million miles of shelves.
                    • This includes materials also collected by overseas offices in India, Egypt, Brazil, Indonesia, Kenya, and Pakistan.
                    • The original Library was burned by British troops in 1814.  Thomas Jefferson donated his personal library of 6,487 books as its replacement.  So our Library of Congress started with his collection.
                    • Today, the Library receives about 22,000 new items each day.  Librarians are able to process around 10,000 per day.
                    • In the US, the materials are stored in three separate buildings in on Capitol Hill and in several off-site storage facilities.  All the library stacks are closed, but as long as you're at least 16 years old, you can go there and look at materials by request, on site in the reading room.

                    Reading room at the Library of Congress. 
                    (Photo from UC Berkeley's Wiki on Visualization)

                    • The Congressional Research Service, which is like a small army of people, responds to requests from Senators and Representatives and provides them with materials or research from the collection.  The idea is that the Library and the CRS will help our elected officials be as informed as possible about all sorts of topics. 
                    • The Librarian of Congress -- the person ultimately in charge of the whole shebang -- is appointed by the President and confirmed by the Senate.  There have been only 13 Librarians of Congress since its inception in 1800.
                    • The current Librarian of Congress is James H. Billington, who was sworn in on September 14, 1987.
                    • The Librarian of Congress is also the person who selects our country's Poet Laureate.  
                    • Our current poet laureate is Kay Ryan. Here is one of her poems:
                    Sharks' Teeth

                    Everything contains some
                    silence. Noise gets
                    its zest from the
                    small shark's-tooth
                    shaped fragments
                    of rest angled
                    in it. An hour
                    of city holds maybe
                    a minute of these
                    remnants of a time
                    when silence reigned,
                    compact and dangerous
                    as a shark. Sometimes
                    a bit of a tail
                    or fin can still
                    be sensed in parks.

                    Library of Congress, About the Library

                    Monday, June 21, 2010

                    Apple #464: Seagulls

                    The other day, I was walking along a lakeshore, nobody in sight in either direction for miles. I looked up and flying just above me was a single seagull.  It was flying at about the same rate as I was walking for a while, and it seemed like a friend.  Then it saw something in the water and it veered off and ahead of me.

                    It occurred to me, we see seagulls all over the place, all the time.  We really take them for granted and are even annoyed but them.  But are there things about them that most of us don't know, that are cool and unusual?

                    No, not these guys.
                    (Photo of A Flock of Seagulls from Kampvuur)

                    These guys.
                    (Photo of a real flock of seagulls in Galveston, TX from

                    • Seagulls can drink salt water.  They prefer fresh water, but they can drink it salty.  They are one of the few land creatures that can do this.  They have a special gland just above their eyes that separates and excretes the salt so they don't have to digest it.  You know a seagull has been drinking saltwater if you see whitish fluid dripping out of its nostrils on the beak, or off the end of its bill.
                    • "Seagulls" is a term people use that actually refers to several species of gulls -- about 47 of them.  The most commonly seen of these species in North America is the Herring Gull.
                    • Herring gulls breed in the summer as far north as northern Canada.  In the winter, they fly south to the warmer states along the Gulf or to the Pacific coast.  Many other species of gulls migrate, but not all of them do.

                    Herring gull
                    (Photo by Eva and Herman)

                    • The California seagull is the official bird of the state of Utah.
                    • This is probably because of a story about seagulls and the Mormons. When the Mormons first got to Utah, the crickets were eating all the crops they'd planted. Then a bunch of gulls showed up from the Great Salt Lake and ate the crickets, which saved the Mormons' crops and the Mormons themselves. A statue of a golden seagull stands in Salt Lake City, in thanks to the seagulls.
                    • Seagulls eat all types of food. They'll scavenge people-food, but they also catch fish and other water creatures. Sometimes they snag fish when they jump out of the water. 

                    Seagull in Seattle caught in mid-dive going after a fish.
                    (Photo from around the sound: seattle)

                    • They also like to eat clams. They open the clam shell by dropping the clams onto a rocky or hard surface from high up in the air, allowing the impact to break open the shell for them.
                    • Some groups of seagulls will stamp their feet on the ground to imitate raindrops, thus encouraging earthworms to surface, whereupon the gulls eat the worms.

                    The laughing gull is the only seagull that breeds in Florida.
                    (Photo from the Internet Bird Collection)

                    • Seagulls make their nests far away from predators and people. Some species fly hundreds of miles from the nest to their hunting grounds and back again in a single day.
                    • Both male and female gulls will sit on the eggs. For about 3 or 4 hours, one will sit on the eggs while the other one hunts, and then they switch.
                    • If they're not on a nest, seagulls will sleep pretty much anywhere they feel safe and protected. If they have to sleep in the open, they'll usually find other gulls and all sleep in a group.  Sometimes, groups of gulls will float together on the ocean's surface and sleep in that group.
                    • They form nests by scraping shallows in sand or dirt. Sometimes they'll line the nest with leaves or feathers or bits of plastic they pick up, or sometimes they don't line the nest with anything at all.
                    • Baby seagulls won't leave the nest until they've learned to fly -- which happens sooner for gulls than for most other birds. But still. The fact that the young stay in nests which are carefully hidden away from humans is why most of us have never seen baby seagulls.
                    • Most types of seagulls are born with dark brown feathers.  It takes three years for their plumage to change colors from nearly all brown to nearly all white with some darker streaks.

                    Juvenile herring gull. Most of its feathers are still brown.
                    (Photo from Planet Thanet)

                    • Herring gulls were hunted nearly to extinction in the 1800s.  Since then, however, the species has revived to historic numbers and has even expanded its breeding grounds.

                    (Photo of seagull from Lucky to be Lucid)

                    Then of course there's the line from Harold & Maude:

                    Dreyfus once wrote from Devil's Island that he would see the most glorious birds. Many years later in Brittany he realized they had only been seagulls. . . . For me they will always be glorious birds. 
                     (Screen shot from HughShows Top 5's)

                    P.S. Regular reader Jason wanted to know, is it true that if you feed rice to a seagull it will explode?
                    • Answer: Nope.  
                    • The story goes that birds can't pass gas, so if they eat rice, the ensuing un-passable gas will cause them to blow up. Depending on the story, sometimes the birds are seagulls, sometimes they're pigeons.  
                    • But birds manage the whole gas problem by vomiting -- which is how they deliver food to their young.  So if they do eat rice -- and they probably won't, to begin with -- they'll just throw it up. 
                    • Believing this rumor to be true, lots of people stopped throwing rice at weddings.  But flinging rice around won't harm the birds.  Rice on the pavement might make your Great Aunt Edna slip and wipe out and break her hip, though.  So it's probably still a good idea to opt for the bubbles or rose petals or whatever else you plant to use.
                    • I don't think rice is especially gas-producing anyway. I mean, if I were going to make up this rumor, I'd make it beans or Brussels sprouts or something.
                    • But there are many variants on this rumor that do involve other materials. Substances that are supposed to cause the blowing up have included
                      • Alka-Seltzer
                      • Aspirin
                      • Mentos
                      • Baking soda
                      • Coca-Cola
                      • Any other carbonated beverage
                    • Animals supposed to be explodable using these items have included
                      • Seagulls
                      • Pigeons
                      • Frogs
                      • Toads
                    • Sorry to disappoint you folks, but none of those rumors is true. 
                    • There's a video online of a bunch of, um, young men feeding bread soaked with a carbonated beverage to seagulls and you see what are apparently seagulls "popping."  If you've seen the video, you've probably noticed that they manage to work in the name of the product several times, even reading information off the can, the video is quite edited so that you don't actually see what they're throwing to the birds, and one of the, um, young men points both his hands at the birds as they "pop" in the distance.  
                    • This video of the seagulls blowing up, ladies and gentlemen, is faked. I'd even bet that it's the energy drink's attempt at advertising. So I will do my part to foil their plan and not say the name of their product or reward them with a link.

                    Coke and Mentos, however, is a completely different story.

                    Here's why that works (there's a brief commercial at the beginning, sorry)

                    Cornell Lab of Ornithology, Herring Gull
                    Steven P. Wickstrom, Information about North American Seagulls
                    Stumblerz, Fun Facts on Seagulls
                    Seegull, 10 Facts You Didn't Know About Seagulls
                    Ask the Exterminator, Seagulls
          , Against the Grain
                    Bird Watcher's Digest, Bird-watching Myths 

                    Monday, June 14, 2010

                    Apple #463: Gulf Oil Spill Response

                    Like most of you, I'm sure, I've been troubled by the amount of oil that's been spewing into the Gulf of Mexico for several weeks now.  I've been trying to figure out how to talk about it here on the Daily Apple.  The purpose of this blog is not to be doom-and-gloomy, so I didn't want to give you a barrage of horrendous statistics.  I also didn't want to be only positive about this rotten situation because that would probably make you want to smack me in the face.  Finally I've figured out information I can provide you with that's neither of those two extremes but which is hopefully helpful, and that is to give you ideas about what you can do to help, if you want to.

                    That's one of the worst things about this.  That that oil is spewing away, and we're all sitting here like blithering idiots while it happens.  But there are things we can do that could help at least somewhat.

                    Cleaning up oil gobs in Louisiana.
                    (Photo by Eric Gay at the Associated Press)

                    I've got lots of information and lots of detail, but if you just want the basics, here are the major phone numbers to call, nationwide:

                    Report Oil

                    Report Wildlife Coated in Oil

                    Offer your vessel for the skimming operations

                    Call to Volunteer
                    This will take you to a voice mailbox, so be prepared to provide your contact information

                    File a Claim with BP
                    or go to

                    Right now, most of the volunteering is being coordinated by one organization, the Deepwater Horizon Response.  This is an amalgam of BP and the multitude of federal agencies involved (NOAA, the Coast Guard, Homeland Security, etc.).  This is who is on the other end of those phone numbers I just listed for you.

                    These are the people who will be coordinating the BP employees, the people who work for the various federal agencies, and the local paid responders. Because they're the coordinators, pretty much everybody is referring people back to the Deepwater Horizon Response website and phone numbers.  However, the Deepwater Horizon Response site is also directing people back to various state-based pages. So you could  try volunteering locally, but you might get directed back to the Deepwater Horizon Response people, or you might get other, mixed results.

                    If you live in the Gulf Coast region, you'll have more opportunities to volunteer.  If you're knowledgeable about birds and other wildlife likely to get oiled in this spill, your services will definitely be welcomed.  If you're like most of us and you don't live on the coast and you don't have any special expertise, you've got two basic choices: you could donate money to a cause of your choice, or you could register as an available volunteer and wait to see if you get called.

                    They all say, please don't go down to the shoreline and start doing stuff on your own.  The crude oil is hazardous material and you could get injured.  If you see an injured animal, unless you're specifically trained in how to help it, please don't try to take care of it yourself, but call the hotline.  Otherwise, please wait until you're contacted by an organization and suitably trained in how to respond.

                    Please heed the signs and wait until you're called and asked to go on the beaches to help.
                    (Photo sourced from Blogger Report)

                    I'm going to list a bunch of organizations that you can try.  I'll start with groups operating on the national level, and then give you links to groups in each state.  Depending on the organization, the state, the individuals involved, as well as your expertise and what you'd like to offer, the opportunities vary quite a lot.


                    Deepwater Horizon Reponse
                    The program coordinating BP and the various government and state agencies who are all working to address the problem.

                    If you want to volunteer directly with them, call 866-488-5816. This is the number that takes you to a voice mailbox where you can leave your contact information.

                    National Wildlife Federation

                    Looking for surveillance volunteers who are willing to work in teams to monitor the 10,000 + miles of shoreline along the Gulf Coast and notify trained rescue teams of oiled and injured wildlife. They want people who have some skills in wildlife observation, some knowledge of Gulf Coast wildlife, especially those species that will be most susceptible to the spill, and be able to use GPS or internet technology for rapid reporting.

                    Most agencies say they don't want stuff, but the National Wildlife Federation does have a small list of stuff they need, to help the surveillance teams:
                    • GPS units
                    • Digital cameras
                    • Sunscreen
                    • Backpacks
                    • Water bottles
                    • Bug repellant
                    • Clipboards
                    • Pens
                    • Hats
                    • Gas cards
                    • Gift cards from major stores such as Target, Staples, Dick's Sporting Goods, Walmart, etc.
                    send to
                    National Wildlife Federation
                      Attn: Oil Spill Volunteer Network  
                       11100 Wildlife Center Drive
                       Reston, VA 20190

                    Donate $ to NWF
                    Donations will go to support wildlife and wild environments affected by the spill.

                    National Audubon Society
                    The Audubon Society's mission is to conserve and restore natural ecosystems, with a particular emphasis on birds.  They have a fairly involved program dedicated to the oil spill response.
                    Bird Information
                    If you're a bird-watcher in the Gulf area, the Audubon Society wants to know what you've seen.  Contact them with information about the location and abundance of birds in your area, which will help them document how the birds have been affected and what the Society will do in response.  Go to, register, and submit your observations.

                    Volunteer with Audubon
                    They say they haven't exactly decided how many volunteers they need to do what or how they'll deploy people.  But they are taking registrations from people who want to volunteer, and once they get their plans settled, they'll begin contacting registered volunteers.

                    Donations to Audubon
                    Donations will help Audubon assist birds affected by the spill and work to restore the environment.

                    This brown pelican is one of the first oil spill survivors.  It was cleaned up by the folks at Audubon and released in Florida's Pelican Island National Wildlife Refuge.
                    (Photo by Richard Baker, President, Pelican Island Audubon Society)

                    International Bird Rescue Research Center

                    The IBRRC's mission is to mitigate the negative impact of humans on aquatic birds and other wildlife. They are one of the non-profit agencies who've been called in to provide expert assistance in helping affected wildlife.

                    They're not accepting offers to volunteer but are referring people to the Deepwater Horizon hotline.

                    Donations to IBRRC
                    Donations will not go to the oil spill, since BP is supposed to pay for that, but donations made here will go to the IBRRC's ongoing programs.

                    Another way to donate to the IBRRC is to adopt a bird.

                    Tri-State Bird Rescue & Research
                    Their mission is to rehabilitate orphaned, injured, or oiled wild birds. They are working with the IBRRC to help wildlife affected by the spill. 

                    Donations to Tri-State Bird Rescue & Research
                    They, too, can't devote donated monies specifically to the oil spill but will put the money into their general operating fund.  That fund will support several projects, including assistance to oiled wildlife.

                    You can donate online or write a check payable to Tri-State Bird Rescue, mailed to 110 Possum Hollow Rd, Newark, DE 19711.


                    Louisiana Volunteer Program
                    or the LA Gulf Response
                    This is a coalition of the State of Louisiana and five non-profit wildlife agencies working together to address the oil spill in Louisiana.

                    Volunteers in Louisiana
                    They're asking for volunteers to register as available to help, but they don't want to deploy any volunteers just yet.  Volunteers will need to be trained to handle the hazardous material that is crude oil, and they want to make sure that local, state, and federal officials are free to do what they need to do before bringing any other people into the mix.

                    They have already been inundated with all sorts of supplies -- some useful, some not -- so they don't need any more stuff

                    Donate to the Louisiana Gulf Response
                    Monies will go specifically to the oil spill recovery program in Lousiana.

                    Volunteer Louisiana Oil Spill Response
                    This is the statewide agency that handles volunteering in Louisiana.  They have one program aimed specifically at Gulf Oil spill recovery.  They don't have specific jobs for volunteers ready at the moment, but they are anticipating needing them once the Unified Command (Deepwater Horizon Response) gives them the go.

                    Whether volunteers are there to help with the Gulf Oil Spill or with Katrina or other recovery efforts, they have housing arrangements available for out-of-state volunteers.

                    Louisiana Business Emergency Operations Center
                    Donations to support recovery in Louisiana can be made here.  Monetary donations are preferred rather than supplies.

                    Second Harvest Food Bank of Greater New Orleans
                    Accepting donations of money, food, and time for those people in Louisiana who have been negatively affected by the spill and its economic aftereffects. 

                    Greater New Orleans Foundation

                    Providing critical services to fishermen negatively affected by the spill.
                    1055 St. Charles Ave, Ste 100
                    New Orleans, LA, 70130
                    504-598-4663 • fax 504-598-4663


                    Volunteer Florida
                    Is gratefully accepting the help from lots of volunteers and is looking for more.  They want people to assist in pre-landfall beach cleanup, fund raising, and helping the trained & paid responders.  They're organizing the volunteer efforts mainly on a county-by-county basis.

                    They say they don't need people from out of state to come down and help -- yet, at least -- but you can help by donating funds if you'd like.

                    Donations to Florida
                    They're not taking donations directly, but they have links to lots of other non-profit and disaster agencies to which you can donate.

                    Jobs in Florida to help the oil spill clean-up
                    These look like fairly basic tasks and I don't know what the pay is like, but they are paying.  You'll have to be screened and trained first, but you can apply here.


                    Governor's Office of Faith-Based and Community Initiatives
                    This office has general information about Oil Spill response opportunities in Alabama.

                    Volunteer in Alabama
                    To register as a volunteer in Alabama, call 888-421-1266
                    or go to the United Way's Oil Spill in Alabama volunteering site.

                    About jobs in oil spill clean-up in Alabama
                    This won't get you to a list of jobs, but it will give you information about where to find such a list, what they're looking for in terms of applications, and what you need to do to apply.

                    Donations to Alabama
                    Pretty basic page with links to donate by credit card, check, or with in-kind supplies.  They weren't looking for many supplies when I checked it, though, so if there's not much there, go back to the monetary donation options.


                    Gulf Coast Oil Spill Disaster Response
                    They have a link on this page to volunteer, but when I clicked on it, it didn't work.  I think it was probably supposed to direct people to

                    Volunteer Mississippi
                    There's a special box where you can volunteer specifically for Gulf Coast oil spill clean-up.

                    Apply for jobs in the oil spill clean-up operations
                    You have to register to use the online system.  You can also call 888.844.3577.

                    Most of the donations being taken at the state level are organized by a particular branch of FEMA and another agency called Aidmatrix.
                    Aidmatrix - Mississippi


                    You can find tons more information and local groups with contact information listed at the Gulf Coast Oil Spill Volunteers facebook group

                    Thursday, June 10, 2010

                    Apple #462: Windows Up and A/C On or Windows Down?

                    I'm about to leave on a road trip for the weekend. So I want to know, does it use less gas to drive with the windows open, which probably creates more drag on the car and thus requires more power from the engine, or is it more fuel-efficient to run the air conditioning, which also requires more fuel?

                    WIndows down or A/C on?
                    (Photo from Climate Clean)

                    Answer: It depends how fast you're driving.

                    • Air conditioners in cars, in general, reduce your miles per gallon by about 10% no matter how fast you're driving.
                    • Driving with the windows down does increase drag on the car, but that doesn't become significant until you reach speeds of 45 mph or so. In fact, windows down at speeds greater than 55 mph will reduce fuel efficiency by 20%.
                    • So this means that when you're driving around town, under 45 mph, it is more fuel-efficient to keep the windows open, A/C off.
                    • When you're on the highway, roll up the windows and turn on the A/C.
                    • Either way, you stand to lose a minimum of 10% in fuel efficiency.

                    Hanging your arm out the car window also increases drag. Older cars were actually designed to allow you to do this classic lean. Newer cars that are required to have firmer side impact ratings and all sorts of safety features have higher side panels and they're often slanted, which makes doing the arm-lean much less comfortable than it used to be.
                    (Photo of Matthew McConaughey in Dazed & Confused from extrawack)

                      • That mph cut-off might vary depending on what type of vehicle you have. An SUV which is already really chunky and large and not aerodynamic is going to see an even greater drop in fuel efficiency, and at lower speeds, when driving with the windows open.
                      • You can help your A/C work better if, when you first start up a car that's gotten hot in the sun, you roll down the windows, open the vents and run the fan to blow as much of the hot air out of the driving compartment. The A/C will thereby have a lower temperature to try to overcome.
                      • Once you're driving and the cabin has cooled off, if your car has a recycle-inside-air button, turn this on. This recirculates air that's in the cabin and already cooled off, rather than pulling in hot air from the outside.

                      The recirculate air button in Volvos looks like this.
                      (Image from the 2002 Volvo S60 owner's manual)

                      • The most efficient option of all is windows up, A/C off. But on an 85 degree summer day, whoo, I don't think I'm going to be doing that!
                      • Various research studies have shown that drivers operating vehicles in cabins that are cooler and less humid tend to be more alert and responsive for longer periods of time, while people in hot, humid, uncomfortable cabins get distracted or sleepy sooner.

                      This will not help your car's fuel efficiency.
                      (Photo from Polls Boutique)

                      Neither will this.

            , Will rolling down windows save fuel or not? August 4, 2005
                      Go Hybrid, The Air Conditioning Myth - Does It Really Burn Up Fuel?
                      Askville by Amazon, Is it more fuel efficient to drive with your windows open or use the air conditioner?

                      Monday, June 7, 2010

                      Apple #461: Shower Curtain Blow-In

                      Regular reader Jason went traveling recently and stayed in a few hotels.  In one of them, he experienced that annoying habit of a shower curtain liner to billow inward while the shower is running.  It blew in so much it clung to him.

                      I have had this happen to me, too. I've noticed it is more likely to happen if the shower curtain liner is especially light-weight and cheap.  It can be most annoyingly clingy and unpleasant, especially if you begin to wonder how many other people showering in this hotel bathroom have been stuck to this same shower curtain.

                      This curtain looks especially prone to billowing in.
                      (Photo from apartment therapy)

                      Regular reader Jason wanted to know why this happens, first of all because it seems to contradict what you would expect.  You would think that the water streaming out of the shower head and beating against the curtain would push the curtain away from you.  But what happens is the opposite.  "I would be interested to know," he said, "the physics behind that."

                      He also wanted to know why this happens so that the next time he's in a hotel room with an incorrigible shower curtain liner, he could maybe do something about it.

                      • As it turns out, regular reader Jason is not the only person to have been interested in the physics behind this question.
                      • For a long time, people have floated different theories about why this happens.  I'll list them briefly so that those of you with bar bets on this topic can settle them quickly.
                      • The most obvious and most-often suggested theory is basically the buoyancy theory.  Air heated by the hot water rises, allowing cooler air to rush in below, thus pushing the shower curtain liner inward.  However, when you turn on the same shower with the same curtain using cold water instead of hot, the curtain still blows inward, which means this theory also blows.
                      • A fancier theory proposed was that the principle is the same as that which enables airplanes to fly:  Bernoulli's principle.  In the case of airplanes, as air rushing over the top of the airplane wing speeds up, the air pressure above the wing drops in a direction perpendicular to the rushing flow of air.  The drop in air pressure is what "lifts" the wing of the airplane up.

                      Diagram of how the Bernoulli principle works.
                      (Diagram from Ted Ewert on Energetic Forum)

                      • Inside the shower, people said, instead of air rushing over the top of the airplane wing, it's the water spray traveling quickly toward the shower curtain.  When you turn the shower on, the velocity of the water traveling through the air makes the air pressure around it drop, thus sucking in the curtain liner.  The problem with applying that principle to this system, though, is that it doesn't account for the presence of water droplets, which act in ways very different than straight-up fluid.  And when one physicist did the math associated with this principle, it didn't result in the shower curtain's movement.  So that theory was discarded.
                      • A third theory said that the shower curtain moves inward because of what's called the Coanda effect. This effect says that when moving air or water hits a convex surface, the two will hug each other remarkably tightly and for a much longer time than you'd expect.  

                      A good demonstration of the Coanda effect in action.
                      (Image from The Worlds of David Darling)

                      • According to this theory, it's not air currents rushing in that blow the shower curtain in but the tendency of the curtain to stay attached to the water as it falls. Exactly how the curtain liner is consistently convex was not thoroughly explained, and the actual motion didn't seem to fit what this principle said would happen, but people bought it for a while because the principle had a fancy name and it was a rather imposing physicist who first suggested it.  But it turns out this theory is all wet, too.
                      • Finally a professor named David Schmidt at University of Massachusetts-Amherst did some pretty extensive research into this question.  He designed a computer simulation of a running shower with a shower curtain in a bathtub in a bathroom.  He divided up the model bathroom into 50,000 observable cells.  He let the simulated shower run at a fairly typical eight gallons a minute for 30 seconds.  
                      • As far as I understand it, he ran some other software made by Fluent Inc. that uses computational fluid dynamics to analyze what happened during that simulation.  The software looked at the droplets breaking up on surfaces, how the droplets were distorted upon impact, and the aerodynamic drag involved with each droplet.  It took 1.5 trillion calculations over the course of two weeks, but then he got the answer.

                      This is Dr. David P. Schmidt, who spent his Christmas break working to dispel the shower curtain mystery for us all.
                      (Photo from Dr. Schmidt's page at U Mass Amherst)

                      • It turns out that Bernoulli's principle is, in fact at work, but the reason Schmidt's calculations with it didn't turn out right initially is because it's happening in conjunction with another principle. That second principle is known as a shear-driven cavity
                      • The shear-driven cavity is a situation when a fluid is moving inside a container with three fixed walls and one moving wall.  In this case, the moving wall is the shower curtain.  I haven't found a very good explanation of how the driven cavity thing works, so let me know if I haven't explained this right. As I understand it, while the water is continually running, the droplets are also slowing down as they travel because of aerodynamic drag.  Supposedly, these two forces happening in equal and opposite directions (water flowing in one direction, being slowed in another) is what gets the air in the cavity that is your shower moving and which, in turn, moves the shower curtain.
                      • When we combine these two principles together, effectively, the spray of the water in the cavity with the moving wall creates a vortex.  Like the center of a hurricane or a tornado, the center of the vortex is a low pressure column.  It is this column of low pressure in the center of the vortex that pulls the shower curtain inward.  Once the water is turned off, the thing creating the low pressure column stops, and the shower curtain will hang normally again.
                      • (I think it's pretty cool, by the way, that there's a mini-hurricane in my shower.)

                      Actually, Schmidt said the water vortex is the shower is most like a dust devil, which are whirlwinds smaller than tornadoes and which can be tilted.
                      (Diagram of dust devils from

                      • The low pressure in the center of the shower water vortex is a very weak force, though, which explains why curtain blow doesn't happen in every shower all the time.  Lighter weight shower curtain liners are more easily moved by the low pressure column. 
                      • So the solution is simple: find a way to make the shower curtain weigh more than the force of the low pressure column.  You can do this in a number of ways.
                      • Get a thicker or heavier shower curtain liner.
                      • Get a shower curtain liner with weights affixed to the bottom.

                      Most curtain liners are sold now with weights or, as in this photo, magnets at the bottom.
                      (Photo from Craft Awl)

                      • Reduce the water pressure coming out of the the shower head.
                      • Curved shower curtain rods which hold the curtain farther away from the vortex -- and from you -- are another solution.  Even if blow-in does happen, they usually keep the shower curtain liner far enough away that it won't touch you. Many of the fancier hotel chains like Hilton and Westin have installed these curved shower rods for exactly this reason.

                      Curved shower rod, some hotels' answer to curtain blow.  You can buy one just like the ones installed in Westin hotel bathrooms for $40.
                      (Photo from bookofjoe)

                      • If you're in a hotel room and don't want to buy a new curtain liner, to say nothing of a new shower rod, you can try these other tactics:
                      • Set your shampoo bottles and suchlike on or against the hem of the curtain liner to weigh it down.  
                      • Wet the backside of the bottom of the curtain liner so it will stick to the side of the tub.
                      • Turn down the force of the water spray.
                      By the way, if you want to see the vortex at work, hang a thin shower curtain liner and turn on your shower.  Doesn't matter if you use hot or cold water.  Now blow in some smoke (where you get the smoke is up to you).  You'll see the smoke take on that vortex shape.

                        The Straight Dope, Why does the shower curtain blow in despite the water pushing it out (revisited)? August 10, 2011
                        David Schmidt, "Why does the shower curtain move toward the water?" Scientific American, July 11, 2001
                        Kate Melville, Mystery Of The Shower Curtain Solved, Science-a-Go-Go, July 13, 2001
                        Ron Lieber, Innovations Eliminate Sticky Shower Curtains, The Wall Street Journal Online, October 11, 2004
                        bookofjoe, Shower curtain 'blow-in,' October 10, 2004
                        WiseGeek, What is the Coanda Effect?
                        CFD Online, Lid-driven cavity problem

                        Thursday, June 3, 2010

                        Apple #460: Belly Button Lint

                        Whew, that was exciting.  Most of you regular readers probably had no idea this was going on, but on June 1, your lowly Daily Apple got enormous amounts of traffic. 

                        The image is kind of small for you to see the numbers, but in one day, I got over 35,000 hits.  That's as much or sometimes more visits than I get in entire months.

                        Tropical storm Agatha resulted in a huge sinkhole opening up in Guatemala City.  Tons of people wanted to see pictures of sinkholes, and they got referred to my entry on sinkholes (which I've updated with photos of that sinkhole in Guatemala, by the way).

                        As you can see, the excitement has dropped off now, though ye olde Dailee Apple is still getting more hits than she used to.

                        So, back to business.  As you'll recall, my last entry was about bikinis.  Naturally, if you're going to slip on a bikini for the summer, I know you'll be worried about that greatest of bikini fauxs pas, belly button lint.  (Also, regular reader Mark wanted to know about the BBL).

                        About 66% of us get belly button lint.  That means 4 of these 6 bellies get the lint.
                        (Photo from Yahoo! Shine)

                        • As far as I can tell, only two people have conducted any sort of scientific or even somewhat scientific study of belly button lint.  Yes, I'm being serious.  
                        • The first guy's research was more anecdotal and fun-spirited, while the second guy conducted his with a much more traditionally scientific approach.  But the first guy asked more people for responses so he had a larger pool of subjects.  
                        • Still, both "studies" were fairly limited in scope, so the belly button lint "facts" I'm presenting are actually more like generalizations based on the limited research these two guys have done.  It is very possible that your belly button lint experience may deviate from these generalities.  That said, here's what they both discovered:
                        • Belly button lint (BBL) is created when the hairs around your navel scrape bits of fluff off your clothes.  The whorl-like pattern of the hair around the navel sort of channels the lint into the center of the vortex, which is your belly button.
                        • The BBL stays there because of other, somewhat less attractive stuff that's hanging out in your navel: sweat, little flakes of dead skin, and dust.  The sweat acts as a sort of glue and helps the lint form into a collective mass and that hangs out in the navel until one day you notice it and scoop it out.
                        • Generally speaking, the hairier you are, the more BBL you'll get.  But, based on the responses the first guy got, if you have a whole lot of hair, it will act as a barrier and won't let the BBL enter the navel in the first place.

                        This probably qualifies as lint-barrier hair.
                        (Photo by tinkerjames on Flickr)

                          • But up to that point, more hair means more BBL.  So this also means that men tend to get BBL more often than women do.
                          • Since we all tend to get hairier as we get older (every place except the top of the head), this also means we'll all be more likely to get BBL as we age.
                          • Aside: I have to differ with this statement, though.  I remember having BBL when I was a kid, but I haven't had any in years.  I have no idea why this is so.

                          This guy is probably a good candidate for moderate BBL.  Except he's not wearing a shirt and his underwear is below his navel.  But if he were wearing more clothes, I bet he'd get the linty navel.
                          (Photo from Alangene on Flickr)

                            • Also, since people with innies have a larger reservoir to hold the BBL, they'll be more likely to get it than people with outies.
                            • Seeming to defy the laws of gravity, more BBL travels up from below than it does down from above. I suspect this is because most of us have innies, and innies have a little overhang which may keep top-down lint from falling in while helping bottom-up lint to get trapped there. 

                            An innie.  See how that overhang would discourage lint from dropping in there?
                            (Photo by kissofclementine on Photobucket)

                            • This also means that people with a snail trail -- the path of hair leading between your belly button and your specials -- are more likely to get BBL.
                            • Since BBL is made up primarily of fibers from your clothes, the color will be an average representation of what you wear.  For most people, the color is nearly always a bluish gray.  I'm thinking this means we wear a lot of jeans.
                            • Some people have noticed that the amount of BBL increases with their level of activity.  This makes sense because if you're moving around a lot, your hairs are going to do a lot more scraping against your clothes.  Form-fitting clothes may also be a contributing factor for the same reason.
                            • One woman reported that an increase in BBL was a good indicator of when she was gaining weight.  Perhaps the shape of her belly button changed as she gained weight and so it trapped and held more lint?  Regardless of the exact cause, she said when she noticed more BBL, she'd take the hint and get to the gym more often, and then the amount of BBL would drop off again.
                            • But generally speaking, research guy #1 found no correlation between people's builds and whether or not they have BBL.
                            • If you get a lot of BBL and you wish you didn't, shaving around the belly button might be the logical thing to do.  But apparently it is not a guarantee.  3% of people who said they had very little or no belly button hair said they still get BBL.
                            • If shaving doesn't work, you may want to consider getting your navel pierced.  Most people with navel piercings report little or no BBL.  Which is a good thing because I'd imagine that could get pretty icky if they did.

                            Look, Ma!  No lint!
                            (Photo sourced from Tales of the Abyss)

                            A Few Belly Button Facts
                            • Your belly button is your first scar.
                            • Belly buttons are as unique as fingerprints.
                            • All mammals have belly buttons.
                            • Barbie dolls do not have belly buttons.

                            These girls are excited because "We've all got belly buttons!"
                            (Photo from Popular Nostalgia)

                            • Some women find the area around the belly button to be very erogenous.  When some men are stimulated around their navel, all it does is make them nauseous.
                            • The formation of belly buttons has always sort of mystified me because what was sticking out winds up turning inward.  That's a pretty amazing transformation.
                            • After you were born and the doctor cut the umbilical cord connecting you to your mother, in time, that umbilical cord shrank and dropped off.
                            • Within the inner workings of the umbilical cord, some of the umbilical cord structures turned into tendons and ligaments inside your abdomen.  The external part of arteries that used to lead to the placenta fell away but internally, they grew downward and connected to your bladder and other internal organs.
                            • The end point of the umbilical cord seals itself and, for most people, usually forms a depression in your stomach -- an innie.  The base of the belly button is attached to the muscle wall of your abdomen.
                            • Sometimes the leftover umbilical scar tissue does not all drop off but stays around.  Your belly button seals itself off, but between the seal and the place where it connects to the muscle wall is that extra scar tissue.  This is what makes outie belly buttons stick out.
                            • Nobody knows for sure why some people wind up with outies while others get innies.  There's a lot of speculation about possible hernias or doctors cutting off the umbilical cord wrong, but nobody's been able to say for sure whether there's any one thing that causes outies.  I suspect that, like so many other things having to do with belly buttons, they're just something that happens.
                            • Estimates are that 90% of people in the world have innies and 10% have outies.  If you have an outie, don't feel bad.  At the very least, this means you are far less likely to get belly button lint.

                            This is Kimbo Slice.  He is a mixed martial arts fighter who has fought in underground street fights and on Ultimate Fighter.  I dare you to make fun of his outie.
                            (Photo from drollgirl)

                            Dr. Karl, The Great Bellybutton Lint Survey
                            Go Ask Alice! Belly button lint
                            Patrick Sawer, "Revealed: The secrets of belly button fluff," The Telegraph, February 28, 2009
                            Scientist Solves Mystery of Belly-Button Lint, FoxNews, March 4, 2009
                            BBC, The Guide to Life, the Universe, and Everything, Belly Button Fluff
                            WiseGeek, Why Do Some People Have Innie Belly Buttons While Others Have Outies?