Alan Nathan
@pobguy.bsky.social
Professor Emeritus of Physics, U of Illinois. Physics of Baseball: baseball.physics.illinois.edu. Mostly post about baseball. Sometimes Con Law, basketball, physics, WW1, Twilight Zone, ...
There's been talk about ball parameters like diameter, how oval they are, how high and wide the seams are, how much they weigh, etc. @johnwgarrett20.bsky.social spent a ton of time measuring a bunch of 2019 baseballs, and I think this is eye-opening. Excel sheet. www.dropbox.com/scl/fi/d3xt5... 1/
dropbox.com
I don't think day-to-day fluctuation in Cd is larger this year than in ealier years. What is different is the overall trend seen in the weekly average.
Can you run game by game cd? By my calc std dev for daily cd is twice as high than anything in a PY? Seems like the CD swing is wild day to day
As far as I know, *nothing* is measured on the balls each game prior to use. Storing balls in the humidor prior to use keeps the environmental factors constant.
Barton L Smith@themagnuspi.bsky.social · 4d agoAs far as I know, no one other than me and Lloyd Smith have measured seam heights, and I think we're the only ones to measure widths, and only on about 100 balls several years ago. MLB does not check anything on the balls at the stadium prior to use, I don't believe.
What are you referring to by "these"?
Patrick Dufour@lephysichien.bsky.social · 4d agoMy feeling is that there might be seasonal variations in average seam height and width due to shifts in tension in the cotton threads that correlate with some environmental variables (could also be time relaxation since construction). Are these measured for each ball on game day?
One more related graph shows normalized home run rate vs Cd (both monthly averages). The home run rate is controlled for exit velocity, launch angle, and air density (especially temperature), so that these factors do not enter into the rate. Rates are ~20% greater in June,July than in April,May.
Alan Nathan@pobguy.bsky.social · 4d agoJuly update on Cd values, which seem to be trending upward. Fly ball distances for given LA are same in July as in June, with both greater than April and May. I will continue to post monthly update for remainder of season.
Cute! I'm about to start work on a paper for a physics journal, probably AJP, on the physics of torpedo bats. I've learned a lot over the past year and it's about time to write it up.
Dr. Meredith Wills ⚾️⚾️👀@bbl-astrophyscs.bsky.social · 4d agoFeel like @pobguy.bsky.social needs to chime in.⚾️ 😋
July update on Cd values, which seem to be trending upward. Fly ball distances for given LA are same in July as in June, with both greater than April and May. I will continue to post monthly update for remainder of season.
Go to nearby Galena IL where some scenes from FoD were shot. While there visit the home where Grant lived just prior to Civil War.
Stephanie@stephy.bsky.social · 4d agoSomeone convince me that we should go to this (or convince me that we should not go)
Source: GIPHY share.google/CEeWcl7n8tM2...
The Good The Bad The Ugly GIFs - Find & Share on GIPHY
GIPHY animates your world. Find The Good The Bad The Ugly GIFs that make your conversations more positive, more expressive, and more you.
share.google
Kyle Lobner@bykylelobner.bsky.social · 6d agoFilm you’ve watched more than six times with a GIF. Hard mode: no Star Trek, Star Wars, LOTR, Marvel, Disney, or Ghibli.
I was pleased to visit the Obama Center earlier this month and examined, among other highlights, displays on two diplomatic breakthroughs where I was proud to play a key role: the Paris Climate Accords and the Iran Nuclear Deal.
Is DOJ going to prosecute former special counsel Jack Smith? Analysis of what we know so far here: substack.com/home/post/p-...
Jack Smith and GOP Shame(lessness)
Ohio Congressman Jim Jordan, the House Judiciary Committee Chairman, sent a referral to DOJ, asking them to bring charges against former Special Counsel Jack Smith.
substack.com
"Under heavy pressure from a federal judge, prosecutors agreed on Thursday to unilaterally withdraw subpoenas issued to New York Times reporters. The move followed sharp grilling about prosecutors’ actions ... The government called the subpoenas to reporters’ family members a 'mistake.'" 1/
BREAKING: Feds withdraw NYT subpoenas into reporting on Qatar-gifted jet
The government called the subpoenas to reporters' family members an “error.”
allrisenews.com
The last time the Red Sox won 15 straight, my mother was pregnant....with ME
Jen McCaffrey@jcmccaffrey.bsky.social · 2w agoFenway Park was 34 years old. A 6-year-old future Hall of Famer named Carl Yastrzemski was just picking up a bat. World War II had just ended. It was 1946, and that was the last time the Red Sox had a 15-game winning streak. On a franchise milestone: www.nytimes.com/athletic/746...
The Boston Red Sox have won 15 consecutive games.
I have also visited Fort Necessity several times, Jumonville Glen (named after the French commander) where the first shooting occurred, and the site of the Braddock battlefield.
Alan Nathan@pobguy.bsky.social · 2w agoJust saw Young Washington and enjoyed it. I was very familiar with the storyline, having read extensively on it. Among my favorites: 1. Young Washington by Peter Stark 2. George Washington's First War by David Clary 3. Braddock's Defeat by David Preston, which I especially recommend.
Just saw Young Washington and enjoyed it. I was very familiar with the storyline, having read extensively on it. Among my favorites: 1. Young Washington by Peter Stark 2. George Washington's First War by David Clary 3. Braddock's Defeat by David Preston, which I especially recommend.
Just to remove any possible confusion, an ICE car is one with an Internal Combustion Engine. Among EV owners, to get "ICE'd" is to be blocked from a charging station by a illegally parked ICE vehicle.
Alan Nathan@pobguy.bsky.social · 3w agoWith my Tesla M3, I average 0.23 kWh/mile while charging at home for $0.12/kWh. That means my cost is $0.028/mile. Compare to ICE car getting 30 mpg at cost of $4.00/gal, for a total of $0.133/mile or nearly 5x worse than the Tesla.
With my Tesla M3, I average 0.23 kWh/mile while charging at home for $0.12/kWh. That means my cost is $0.028/mile. Compare to ICE car getting 30 mpg at cost of $4.00/gal, for a total of $0.133/mile or nearly 5x worse than the Tesla.
Sky Kalkman@skykalkman.bsky.social · 3w agoLord of factors, but EVs effectively get 100-120 mpg going by cost. Probably more currently given price of gas Of course, mpg increases are non-linear, like ERA+. Really should be using gallons-per-mile.
Didn't forget. But he was beyond age 28 then.
Exploring Baseball History@bballhist.bsky.social · 3w agoDon't forget Korea!
Ted did it while missing his years 25-27 seasons.
Tangotiger@tangotiger.com · 3w agoI've long considered Juan Soto as the most genius batter of our generation. We may need to extend this to one of the most genius batters in history of baseball What I like about stat from Sarah is it highlights players of past: We know about Ted, but maybe we dont appreciate Mick and Foxx enough?
Can someone post a link that is not behind a paywall
Jon Heyman@jonheyman.bsky.social · 3w agoBryce Harper says Home Run Derby balls are juiced. MLB says they are no different than balls used in the regular season, and treated no differently (in here: a comparison of HR distances, and other possible explanations) nypost.com/2026/07/16/s...
