Your marvelous brain - II

This is the second part* of a group of posts on the wonders of your brain.  Situation: The ball is flying toward you, but how do you know where and when it will arrive?

Yes, it is all about the flying ball. One thing you know, if you’ve every played catch, volleyball, baseball, basketball, or an assortment of other sports where a ball is in play, is that it goes up and down, but more.  Here’s just a sample of what that good ‘ole brain can do.  It can compute  the speed of the ball and when it will arrive. It’s done automatically, a consequence of evolution.  Every animal can do the same thing, that is to compute when and where a moving or flying object will reach them.   For us humans, not sure about you other readers, much of this happens in the cerebellum, a part of the brain near the brain-stem.

Most flying objects, like the ball, change height and speed in the air due to gravity and air resistance. Another remarkable consequence of evolution, reading this is also a skill owned by us and most animals.  The hunter and the hunted need these to survive, like eat that day or live until the next one. 

Football quarterbacks have the even more difficult task of computing the range, speed, gravitational effects, and not only those but with the receiver running down or across the field, coordinate all this data into making a precise throw to the moving target.  This is a learned skill, but again, it is done automatically by the brain. (This just isn’t any time to compute!) Birds of prey are also masters of exactly these skills, as their survival depends on solving complex pursuit problems, a skill level even greater than the humble quarterbacks. For them, their brain is mostly hard-wired, but still learning is a factor. 

Spin. The next level of trajectory computation is easily seen on the tennis court.  It’s not for maybe you and me, but good tennis players can make even higher orders of computation.  It is the consequence of ball spin, the so-called Magnus Effect**.  They don’t just strike the ball to get it over the net; they hit the ball in such a way to put a spin on it, and this changes its natural trajectory. A flying object with spin takes a different path than simply throwing a ball.   This is how they can hit the ball so hard, and it still lands in the opponent’s court. (If I could hit the ball so hard, with my simple flat motion, it would land in the next county.)  They can put either backspin or topspin on the ball.  You might say during the match, your brain operates like an aeronautical engineer, though a really tiny one.

Let’s clarify.  The quarterback, tennis player, soccer player, and all make conscious decisions on what to do.  After that, mostly automatic processes compute and carry out the logistics.  But… while the conscious brain plans out the goal, and the little engineer makes the computations, it is  up to the muscles to execute.  Tired muscles often fall short of what’s needed.

Topspin, for example, forces the ball down sooner than just gravity alone would.  When spinning balls land, the spin is transferred into a “kick” and bounce higher, making them more difficult to return.  The experienced player can read this spin and other factors within a tiny fraction of a second to determine where it will land – another remarkable feat.  This ability also allows them to get there to return the ball, to “see” if it will go out of bounds, or if it will land out of physical range to return.   The good tennis player can also make the ball spin sideways,  giving a laterally curve, especially on the serve. The kick often makes it “leap” right out of play.   Typical tennis ball spin rates are 3000 rpm –faster than the rpm of your car engine but slower than your blender. Wow!!!

Your marvelous brain, with a dash of learning and practice, does remarkable things without any apparent mental computation, much less contemplation.  Yet, the brain does work hard all the time during a tennis match, particularly when returning a shot.

One certainly could say that acquiring all these skills, clearly connected with the brain’s hard-wiring, is a form of advanced problem-solving. Training – Learning - Natural ability.  All are essential. Call this the tripod of excellence.

EXTRAS:

1. Placing spin on the ball is what baseball pitchers use to make the ball curve.  Your slice (or hook) in golf is caused by the spin you create when club face strikes the ball very slightly at an angle from the true perpendicular from the arc of the swing. The spin on the football pass, however, is placed for stability of flight.  Topspin on the moon cannot exist - nor air resistance.  Many sports on the moon will be boring. 

2. Some hunters use high-speed to defeat the prey’s natural flight defenses by overriding their ability to react, e.g. the arrow, the strike of a serpent. Only humans seem to use spin.

3. These same “flight” skills, less the spin factor, make safe driving possible. Your brain makes multiple computations all the time about the approach of other vehicles, stop signs, pedestrians, and other events of driving.  And all at lightening speed.

4. The Magnus effect (1853) is a special application of the Bernoulli theorem which states the pressure on a object is less on the side where the air speed is greatest.  It’s the same principle that allows air flight, with speed forcing the air over the top of the wing faster than the bottom generating lift.  So air flight and top spin arcs result from the same physics.

5. Backspin has the opposite affect on the ball, giving it a slight lift, causing the ball to “float” or “sail” low across the net. As well, the bounce is low.  

*http://used-ideas.blogspot.com/2012/06/your-marvelous-brain-problem-solving.html

**http://ffden-2.phys.uaf.edu/webproj/211_fall_2014/Max_Hesser-Knoll/max_hesserknoll/Slide3.htm.