Shakehand beats penhold -- again!

Just like he did in London last summer (click here for my blog post on that match), China's Zhang Jike defeated fellow countryman Wang Hao in the finals of a major table tennis tournament, this time the 2013 World Table Tennis Championships in Paris.  What fascinates me about a match featuring Zhang and Wang is the contrast in playing styles.  Zhang uses a shakehand grip whereas Wang employs a penhold grip.  The shankehand grip is so named because one appears to be shaking hands with one's racket   The penhold grip is also well named because one appears to hold the handle of one's racket as one might hold a pen.  In such a grip, the racket appears "upside down" to many novice players.

What astounds me about Wang's play is that he is able to use the backside of his racket for his backhand.  As a less-than-stellar penhold player myself, I use a racket with no playing surface on the backside, which is fairly standard for a penhold player.  My backhand is by far weaker than my forehand, which is why Wang's style intrigues me.  His wrist appears rubbery to me as I watch him execute hard backhand smashes.  I can only dream of such backhand skill!

Despite Wang's backhand prowess, he had to settle for second behind Zhang, who has a backhand shot as good anybody playing today.  Zhang makes use of a slightly less spongy surface on his racket so as to ensure more translational kinetic energy transfer to the ball at the expense of a little rotational kinetic energy, meaning he loves to play fast.

Table tennis at the highest levels involves smashes hard enough to lead to air drag greater than five times the weight of the ball and a Magnus force, which is due to the ball's spin, greater than twice the ball's weight.  That's why you will see players sometimes playing well back of the table's edge -- the ball moves fast with lots of spin, meaning it curves quite a bit more than with gravity acting alone.

The women's final of the World Championships saw Li Xiaoxia, the gold medalist in London, defeat Liu Shiwen, both also from China.  Li and Liu each use a shakehand grip.

If you happen upon some table tennis while flipping channels on your television, watch for a little while and pay close attention to the way each player holds his or her racket.  Note, too, the type of surface on each side of each player's racket.

Celebrate reason today!

Today is the National Day of Reason in the US.  Started ten years ago, this day represents a push back against the National Day of Prayer.  The separation of church and state was an important part of our country's founding.  People are free to assemble and practice whatever religious beliefs they hold, and I would never want that freedom to disappear.  There are many people, however, who think it unconstitutional to use taxpayer money to fund a day of prayer.  As one of those people, I wish to add my voice to those who value reason and view it as a human being's greatest virtue.

To celebrate reason today, I will introduce my students to the beauty of Fourier analysis.  That we can untangle the complexity of bizarre wave patterns is something that always puts a chill on my spine.  Doing science well means setting aside a fear of being ignorant, asking questions, investigating the natural world, and then letting data and evidence take you to conclusions that may or may not make you happy.  Your opinion of the conclusions reached by good science has no effect on those conclusions.  Fourier's work survives nearly 183 years after he died because of the reason and brilliance he put into it.  If you ever do any type of signal processing, be sure to thank Joseph Fourier!

If you are interested in reading more about the National Day of Reason, click here.