22 April 2012

Earth Day, Feynman, Science, and Beauty

Today is Earth Day, which, having also been born in 1970, is as old as I am.  International celebrations of Earth Day began 20 years later.  Like anything else, the way in which people observe Earth Day will be varied, from complete apathy to total euphoria.  As science helps us understand our less-than-special place in the universe, we slowly come around to the idea that we share our environment with our fellow animals.  We abuse our environment to our own peril.  What constitutes "abuse" is sometimes cause for great debate.  Instead of adding fuel to that fire, I wish to focus here on the beauty of the natural world.

We all experience the world in different ways.  I am unfortunate enough to speak only English.  I envy those, like my wife, fluent in both English and Japanese, who possess ways of formulating thoughts for which the English language is not adequately equipped.  They are capable of seeing the world in ways that I cannot.  As someone who speaks English, I may have ways of seeing my surroundings that someone in, say, China cannot.  Then again, a person living in China may have some ways better than mine for seeing his or her environment.  Language helps us formulate thoughts, communicate them to others, and learn from others.

Mathematics is a language, and a very special one at that.  What makes it special is that it is universal.  I have been around people from other countries who I could not talk to in English.  But, once we started putting equations on a chalkboard, we could share our thoughts.  Physics enhances the beauty of mathematics by helping us understand our natural world.  I have always enjoyed the idea that mathematics is the language of the universe, but physics is the poetry.  Just like the words we think of when hearing the word "language," mathematics is a language that provides us with a unique way of seeing the world.

Unfortunately, too few people possess enough fluency in mathematics to really "see" the world in the way some scientists can.  The joy I acquire when probing for a physical understanding of what happens in a great sporting moment is as heart-stopping for me as the moment itself.  Keeping with the definition Socrates gave us for a wise person, the more I know, the more I realize what I don't know.  The desire to "know" why something happens pushed me into being a physicist.

There were other influences that pushed me into physics.  One was seeing Richard Feynman drop an O-ring into ice water during a hearing to determine the reason why the Challenger shuttle exploded on 28 January 1986.  I was mesmerized seeing a world-class physicist make something so complicated seem so simple.  Like many physicists of my generation, Feynman was one of several that we admired greatly.  Though I know that I'll never see the world as well as he did, I love the life-long struggle to see how close I can come.

I usually share a little bit of Feynman with my classes once or twice a semester.  Just this past Friday, I showed my Classical Mechanics students a few minutes of Feynman lecturing in 1964 to an audience at Cornell as part of his lecture series entitled The Character of Physical Law.  This was just about a year before Feynman got the call from Stockholm.  With all his charisma, charm, and enthusiasm for physics, Feynman ended the second lecture with some wonderful words about how mathematics helps us see beauty in the universe.  Click here for a YouTube video of his second lecture.  Go to about the 51:30 mark and watch until the end (about two-and-a-half minutes).  As Feynman says, "For you who don't know mathematics, it's really quite difficult to get a real feeling across as to the beauty, the deepest beauty, of nature." Mathematics may be difficult, but it's well worth the effort to learn some of that wonderful language.

So, I celebrate Earth Day today by doing physics.  I hope to gain a little more understanding of the natural world and further appreciate its beauty.  

15 April 2012

Baseball Turns 65 Today!

On 15 April 1947, Jackie Robinson took to the diamond in Brooklyn's Ebbets Field.  Robinson did not get a hit that day, but the Dodgers beat the Boston Braves 5-3 (click here for the box score).  What made that day special 65 years ago is that Robinson broke the color line in Major League Baseball.  Robinson became the first black man to play Major League Baseball in the 20th century.  There are many, many books you can read about how the courageous Brooklyn general manager, Branch Rickey, selected the even-more-courageous Robinson to bring forth enlightenment to a racist sports world.  I'll not retell that story, but offer the perspective of a 41-year-old physicist who loves baseball.

Born in 1970, I grew up in love with baseball.  Baseball was fully integrated on the field, but not so much in management.  Color didn't mean much to be when I watched baseball and when I played the game as a child.  I etched E-5 on my glove just like Brooks Robinson did; I flapped my elbow like Joe Morgan.  Greatness appealed to me and I never thought about a great "white" player or a great "black" player, just a great "baseball" player.

I also relished baseball history.  Somehow baseball stats just stuck in my head, even to this day.  I collected baseball cards, got autographs, and read book after book on what seemed the perfect game to me.  I certainly read about the Negro Leagues, but like everything that happens to us before we are born, the idea of blacks having their own league because they couldn't play with whites was an abstraction for me.  I felt sick over the idea that great black players weren't allowed to compete in the Major Leagues, but that feeling arose only because of words I read in a book.

So what did I do as a geeky baseball-playing kid?  I wondered if Babe Ruth could have hit 60 homers in 1927 if, every now and then, he had to face a cocky 21-year-old Satchel Paige.  Would Lefty Grove have gone 31-4 in 1931 if, every now and then, he had to look over to first base and see a 28-year-old Cool Papa Bell in the prime of his career ready to take off for second at the first hint that Grove was about to deliver his pitch?  Both Jimmie Foxx (in 1932) and Hank Greenberg (in 1938) challenged the great Babe Ruth's single-season home run record.  Imagine Josh Gibson playing his age 18 to age 27 seasons in the hitter-friendly 1930s.  Would Gibson have broken Ruth's record?

We'll never know the answers to those questions (and many more) that floated around in my young head.  But look at what we do know.  Science is about acquiring data and evidence.  Jackie Robinson won the Rookie of the Year award in 1947 and the National League MVP award two years later.  When the Hall of Fame voted in Robinson and Bob Feller in 1962, affirmative action played no role in the former's vote total.  If Feller's fastball could make a Major League hitter flinch, imagine what seeing Jackie Robinson dance back and forth on second base did to Major League pitchers.  The data and evidence were there in abundance.  Not only did Jackie Robinson belong in the Major Leagues, so did his peers in the Negro Leagues.

Think about where science has taken us in the past 65 years.  The work Watson and Crick did in the early 1950s on DNA gave us biochemical understanding of who we are.  I've always loved it that Watson and Crick were awarded their Nobel Prize in 1962 -- the same year as Jackie Robinson's election to the Baseball Hall of Fame.  Science does not think of people as divided into "tribes" and "races."  We are all part of a species of primates called homo sapiens.  No matter our gender, race, or country of origin, variations in our collective DNA are incredibly tiny compared to other animals (click here for an interesting research paper on this topic).

Our biochemical understanding of ourselves couples quite well to the evolutionary ideas put forth by Darwin in 1859.  Researchers across many scientific disciplines have provided enormous amounts of data and evidence to give us an understanding of how we got here.  We know, for example, that our human origins date back about 200,000 years in Africa, meaning that we are all Africans.  Think about how much science and reason enlighten us.  Push credulity, hatred, and ignorance aside, then think about how cool it is that you and I share common ancestors with Jackie Robinson.  Now that is something to celebrate!

Finally, ponder how short a time length 65 years is.  Nearly 13% of the more than 313 million people in the US are at least 65 years old.  About 1 in 8 people in the US were alive when Jackie Robinson took the field on that pioneering day 65 years ago.  About 9% of our population is at least 70 years old, meaning that about 1 in 11 people probably have memories of Jackie Robinson breaking the color line.  If you know someone of that advanced age, talk to him or her today about Jackie Robinson.  We lose living witnesses to history every year.  Let's keep their stories alive.

11 April 2012

Magnus at the Masters!

NOTE:  I wrote the following analysis on the evening of Sunday, 8 April 2012, not long after Bubba Watson won the Master's.  I've been delayed getting my analysis posted.

Bubba Watson's second shot on the second playoff hole of the Master's was a thing of beauty.  If you have not seen it, click here (go to the 5:13 mark on the video).  It not only won him the Masters, it was a great example of a golfer intentionally using the Magnus force to his advantage.  The Magnus force is the force associated with a spinning ball.  It helps explain curveballs in baseball and banana kicks in soccer.  A spinning ball whips air around its back in an asymmetric way.  What that means is that the air is whipped off to one side or the other instead of straight back.  Think of how a boat rudder works.  Turn the rudder to one side and water gets deflected, which makes the boat turn.  Newton's third law tells you that if a ball deflects air in one direction, the air must deflect the ball in the opposite direction.

Golfers use the Magnus force all the time.  Their club faces are grooved to help get the ball spinning.  On tee shots, a well-hit ball will have backspin.  The Magnus force associated with that backspin has an upward component, which fights gravity and helps keep the ball in the air a little longer than if the ball wasn't spinning.  Think about a good Major League fastball.  The backspin prevents the ball from dropping so much on the way to the plate.  A left-handed golfer like Bubba Watson will slice if he hits the ball in such a way that it has a component of spin that is counterclockwise (as seen from above).  What Watson did on the 10th at Augusta was go for a hook.  Seen from above, his ball had a component of its spin that was clockwise.  The ball thus came out of the trees spinning in such a way that the ball curved to the right.  Given that Watson was in the trees on the right side of the fairway, it was the perfect shot.  Most amateur golfers will hook or slice without trying to do so.  Watson showed us when a hook is a good thing.

The physics fun didn't stop with the ball in the air.  Once the ball hit the green, its spin caused it to take a right turn in front of the hole.  The ball eventually stopped rolling and a green jacket lay just ten feet from the hole.  Watson was then able to two-putt for the win because Louis Oosthuizen was not able to find the green with his second shot.  Bubba Watson can thank the Magnus force for the new addition to his wardrobe!

04 April 2012

Coriolis, Kobe Bryant, and Things Unseen

Tornadoes devastated parts of Dallas, Texas yesterday.  After viewing some truly terrible video footage on televisions at the gym this morning, I can only hope that there are no fatalities.  Seeing the tornado footage got me thinking about various forces due to the air.  Air forces play crucial roles in many sports, especially those in which balls are bandied about.  The drag force is usually the dominate component of the air's net force on a ball in flight, though the Magnus force is strong enough to alter trajectories and give us wonderful banana kicks in soccer and curveballs in baseball, just to name two examples.

The forces involved with the motion of air in a tornado are certainly much larger than the force a ball feels from the air.  But what is actually pushing on the air itself to make a tornado?  The physics behind tornado formation is quite complicated and not really what I wish to devote space to here.  Suffice to note that air accelerates when pressure differences exist.  Formation of a tornado is greatly dependent on local weather conditions.  What is not a key player in the formation of tornadoes is the Coriolis effect.

The Coriolis effect is named after the French scientist Gaspard-Gustave de Coriolis (1792-1843).  The effect arises when one tries to apply Newton's laws in a reference frame, called "noninertial," where those laws are not valid.  A good rule of thumb for identifying a noninertial reference frame is to note if the frame is accelerating with respect to some previously defined inertial frame.  If we imagine the stars in the sky as being "fixed" over the time we are doing an experiment, then the distant stars sit in an inertial reference frame (they certainly move, and they accelerate, but over the time of our experiments, we don't see much change!).  Usually the Earth is taken to be an inertial frame in which we apply Newton's laws of motion.  Locally, noninertial effects are not that noticeable.  But take a large mass of air in a hurricane or a cannon shell that travels over tens of kilometers and the fact that the Earth is noninertial comes into play.  The Earth turns on its axis, which means that objects on Earth's surface are constantly accelerating.  Recall that acceleration is the time rate of change of velocity, which is a vector that has both magnitude and direction.  Objects on the surface of a spinning object must be accelerating because velocity vectors are constantly changing directions.

It turns out that tornadoes involve air masses that are much too small to be concerned with the Coriolis effect.  If one wishes to calculate the influence of the Earth's rotation on projected objects, one must solve some rather fun equations.  What pops out of those equations is that objects projected in the northern hemisphere, regardless of velocity direction, are deflected to the right because of the Coriolis effect.  The deflection is to the left in the southern hemisphere.  When one analyzes air flows and pressure differences, the Coriolis effect explains why hurricanes in the northern hemisphere rotate counterclockwise as seen from above.  Hurricanes rotate clockwise as seen from above in the southern hemisphere.  Please note that if tornadoes comprise masses too small for the Coriolis effect to play a noticeable role, toilet water is even less effected.  Don't believe the nonsense about the Coriolis effect causing toilet water to spin a certain way when flushed!

If the Coriolis effect won't bother a tornado, it certainly won't bother most of the sporting events we watch.  Did you see Kobe Bryant's great three-point shot last night?  Click here for video.  I calculate that the rightward deflection of Kobe's shot was about half a millimeter, which is about two hundredths of an inch.  Now, the ball was definitely bouncing around the rim after Kobe shot it.  But I don't think half a millimeter was the difference between going in and staying out.  The Coriolis effect is essentially unseen in the sports world.

There were a couple of things that happened yesterday that had not been seen before.  The first was that Baylor University women's team became the first men's or women's team to go 40-0 as they won their second national title (the first coming in 2005).  Baylor's Brittney Griner was sure fun to watch.  Besides all the hype surrounding her becoming the second woman to dunk in the tournament, she possesses a great inside game that is fun to watch.

The other previously unseen thing that happened in the sports world last night was the great Lionel Messi scoring his 14th goal for Barcelona this year in Champions League competition.  Messi scored on two penalty kicks against AC Milan.  What seems almost unfair is that Barcelona not only has the services of Lionel Messi but Andres Iniesta, too.  Iniesta had a great goal in the 53rd minute of the match.