Alan Nathan
@pobguy.bsky.social
1.7K followers 240 following 480 posts
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, ...
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Got it! Thanks for clarifying.
just the model notation, it'll solve for a batter specific intercept to replace the 1
Why the "1"?
of course, the model is set up as bat_speed ~ 1 + A*y_intercept + B*y_intercept^2 and I'm just solving for A and B by batter
Can you provide some details on how you do the constant jerk fit.
a collection of unique swings when modeling bat speed as a function of intercept point assuming constant jerk (thus a function of int and int squared)
Reposted by Alan Nathan
That was quite a game at Fenway 12 years ago tonight.
Make that 1840-1920
Just got the library copy of "Born Equal: Remaking America's Constitution, 1860-1920", by Akhil Amar, my favorite constitutional historian. This will be the 4th of his books that I have read.
Just got the library copy of "Born Equal: Remaking America's Constitution, 1860-1920", by Akhil Amar, my favorite constitutional historian. This will be the 4th of his books that I have read.
We all learn about quantum tunneling in atomic systems in introductory courses in quantum mechanics. The current Nobel Prize was for the observation of such tunneling in much larger systems, as initially predicted by my UIUC colleague Nobel Laureate Tony Leggett.
www.nytimes.com/2025/10/07/s...
Curveballs have a downward Magnus force, which is reduced with a tailwind, making it more sustainable to the deadly hanging curveball.
Reposted by Alan Nathan
“The Twilight Zone” premiered on this date in 1959.
Colored-pencil card drawing of Rod Serling
Surely you jest!
You know what I miss? The curse of the Bambino. In the days of the curse, no way would the Yankees load the bases in the bottom of the ninth against Boston and not walk it off.

Also you know the Yankees never win a World Series with a republican in the White House.

#superstitions
As is by custom on this anniversary, I read again John Updike's great essay, with the words "God's do not answer letters."
“Less Than 11,000 Hub Fans Bid Kid Adieu” just doesn’t have the same ring
10,454 to be exact
Less than 11,000 were in attendance, confirming that Boston fans are just the worst.
Today is the 65th anniversary of Ted's last swing (shown below), resulting in his 521st home run.
The thing I find most interesting about the video is how quickly the vibrations are damped, despite being "free" (i.e., no hands).
We need @pobguy.bsky.social on the case!
the bat moved like a high school Peter Pan production's 1st rehearsal
And guess what...it's my birthday too!!
Happy Birthday to the US Constitution!
Happy Birthday to the US Constitution!
Here is a clip from that episode, "Nothing in the Dark":

youtu.be/9tfyv4BZRug
As we remember the life of Robert Redford, here is his appearance on The Twilight Zone (S3,E16, January 1962), featuring truly excellent performances by both Redford and (especially) Gladys Cooper.
RIP Mr. Redford
One of my favorite Twilight Zone episodes "Nothing in the Dark".
As we approach the 50th anniversary of the "thrilla in Manila", Vann Newkirk has written a superb article about Ali and Frazier, their relationship, and the fight. It is as good a piece of sports writing as I've seen in recent years. I highly recommend.
www.theatlantic.com/magazine/arc...
The Greatest Fight of All Time
Fifty years ago, Muhammad Ali met Joe Frazier in Manila.
www.theatlantic.com
He was an excellent governor who knew how to work across the aisle, mainly with Mike Madigan, to get things done.
I grew up and lived in Illinois most of my life. Jim Edgar is probably the last well-liked governor of that state. People on both sides of the aisle respected him, didn't trash talk him after he was out of power, and - most importantly - he was never involved in a scandal that landed him in prison.
Jim Edgar, the two-term Republican governor who guided Illinois through much of the 1990s with a low-key yet intense persona and a meticulous focus on fiscal matters aimed at preparing the state for the 21st century, died Sunday.
Yes
Jason @jasoner.net · Sep 14
Ok, so if I substitute that sqrt expression for v, then substitute vx - vwindx, vy - vwindy, etc, that should work?
Radians/sec
Jason @jasoner.net · Sep 14
Also is omega spin rate (rpm) or angular velocity (radians per second)? I sort of assume the latter, but I figure it could be either