Physics 199BB The Physics of Baseball

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Physics 199BBThe Physics of Baseball

• Fall 2007 Freshman Discovery Course
• Alan M. Nathan
• 403 Loomis
• 333-0965
• a-nathan_at_uiuc.edu

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Textbook for Course
Bob Adair
Blending scientific fact and sports trivia,
Robert Adair examines what a baseball or a
baseball player in motion doesand why. How fast
does a batted ball go? What effect do stitch
pattens have on wind resistance? How far does a
curveball break? The answers are often
surprisingand always illuminating.
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(No Transcript)
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We will cover the entire book.
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Other Useful Books
The book is written for the inquiring
layperson many controversial claims about
the game are addressed andresolved by this
book.
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Other Useful Books
The primary purpose of this book is to collect
and present in one place interesting examples of
the physics of sport for the benefit of
physicists, physics teachers, students, and other
sports-minded and scientifically curious readers.
Some good articles, but lots has happened since
1992.
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Other Useful Books
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Internet Resources

• My web site
• http//webusers.npl.uiuc.edu/a-nathan/pob
• I try to keep the site up to date with the most
  current links
• PITCHf/x Gameday Logs
• http//gd2.mlb.com/components/game/mlb/year_2007/
• Useful for analysis of pitched ball trajectories
• Hittracker
• http//www.hittrackeronline.com/
• Useful for analysis of home run trajectories

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Organization of the Course

• Monday, 3-5 PM
• Rm. 236 Loomis
• Sometimes Rm. 257 Loomis (computer lab)
• Sometimes we will do labs
• High-speed camera
• Pitching machine
• modal analysis equipment
• Computer calculations
• Hopefully we can watch the Illini practice

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What do I expect of you?

• Come to class
• Participate in discussion
• Do homework
• Mostly computer exercises
• Do a special project
• Research project, paper, presentation,
• More on this later

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Additional Resources

• Physics of Baseball Blog
• https//teamphysics.physics.uiuc.edu/SiteDirectory
  /PHYS199BBBlog/default.aspx
• Physics of Baseball Wiki
• https//teamphysics.physics.uiuc.edu/SiteDirectory
  /PHYS199BBwiki/default.aspx
• Physics of Baseball Teamsite
• https//teamphysics.physics.uiuc.edu/SiteDirectory
  /PHYS199BBTeam/default.aspx

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After taking this course, you will be able to
answer the following questions

• What matters more pitch speed or bat speed?
• Does juicing the ball make a difference?
• What/where is the sweet spot?
• What is the ideal bat weight?
• Is corking the bat effective?
• Does the batters grip matter?
• Why does aluminum outperform wood? By how much?
• Can a curveball be hit farther than a fastball?

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After taking this course, you will be able to
answer the following questions

• Is there such a thing as a rising fastball?
• How much does a curveball break?
• How does a knuckleball work?
• What the heck is a gyroball?
• Why do fly balls often curve toward the foul
  line?
• Why are popups to the infield often difficult to
  catch?
• How far did that home run travel?

and lots more.
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A Philosophical Note
the physics of baseball is not the clean,
well-defined physics of fundamental matters but
the ill-defined physics of the complex world in
which we live, where elements are not ideally
simple and the physicist must make best judgments
on matters that are not simply calculableHence
conclusions about the physics of baseball must
depend on approximations and estimates.But
estimates are part of the physicists
repertoirea competent physicist should be able
to estimate anything ... The physicists model
of the game must fit the game. Our aim is not
to reform baseball but to understand
it. ---Bob Adair in The Physics of
Baseball, May, 1995 issue of Physics Today
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More Philosophy

• Physics is an experimental science
• What tools are there at our disposal?
• The game itselfthe ultimate laboratory
• Tools to study bats and batting
• Low speed collisions -- movie clip
• High speed collisions movie clip
• Modal analysis of bat vibrations demo and next
  slide
• Tools to study the flight of the baseball
• High-speed video movie clip
• PITCHf/x movie clip plus slide
• Trackman radar
• Motion analysis

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Modal Analysis of a Baseball Bat www.kettering.edu
/drussell/bats.html
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Vibrations and Broken Bats
movie
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Barry Bonds 756th Home Run
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Thanks to J. J. Crisco R. M. Greenwald Medicine
Science in Sports Exercise 34(10) 1675-1684
Oct 2002
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Using Motion Analysis to Study Baseball
Trajectories
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Motion Analysis Geometry
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• Motion Capture System
• 10 cameras
• 700 frames/sec
• 1/2000 shutter
• very fancy software
• www.motionanalysis.com

• Pitching Machine
• project horizontally
• 50-110 mph
• 1500-4500 rpm

MOVIE
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Typical Data
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Basic physics and math that we will review
quickly

• Velocity and acceleration
• Motion with constant acceleration
• x(t) x0 v0t 1/2at2
• Forces and Newtons Three Laws
• Especially the 2nd law
• F ma
• Vectors
• Geometry and trigonometry

See handout sheet
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First Assignment

• Read Chapters 1 and 2 of Adair
• Make sure you have Excel installed on your
  computer and know how to use it