FiveThirtyEight takes a look inside the balls used in major league baseball using X-rays to see what has been pysically changed in recent times. The physical changes are probably the main cause of the upswing in home runs noticed. Multiple independent investigations have shown differences in the characteristics of the balls and the way they perform.
MLB and its commissioner, Rob Manfred, have repeatedly denied rumors that the ball has been altered in any way — or "juiced" — to generate more homers. But a large and growing body of research shows that, beginning in the middle of the 2015 season, the MLB baseball began to fly further. And new research commissioned by "ESPN Sport Science," a show that breaks down the science of sports, suggests that MLB baseballs used after the 2015 All-Star Game were subtly but consistently different than older baseballs. The research, performed by the Keck School of Medicine at the University of Southern California and Kent State University's Department of Chemistry and Biochemistry, reveals changes in the density and chemical composition of the baseball's core — and provides our first glimpse inside the newer baseballs.
(Score: 2, Informative) by Anonymous Coward on Monday May 28 2018, @07:32AM (3 children)
There's in fact a recent paper (nature communications, therefore free to read: https://www.nature.com/articles/s41467-018-04177-w), [nature.com] where the authors study the movement of spheres with different moments of inertia in a fluid.
It turns out that you can control the "weirdness" of the trajectory by changing the moment of inertia (i.e. the difference between ball filled with sand vs mostly empty ball with a chunk of iron in the middle), and they actually mention that ball sports can be made more interesting if you take this research into account. Quote from conclusions:
"Other avenues of application could lie in sports ballistics, where zig-zag and spiral trajectories add to the unpredictability of the game. While this has historically been achieved by introducing surface heterogeneities and/or spin to the ball42, rotational inertia could be used as an additional lever to trigger such path-instabilities, thereby lending richer diversity to various ball sports."
(the 42 refers to a review entitled "sports ballistics", https://www.annualreviews.org/doi/10.1146/annurev-fluid-010313-141255). [annualreviews.org]
(Score: 0) by Anonymous Coward on Monday May 28 2018, @07:46AM (1 child)
sorry for the links... I thought the brackets would be split from them automagically...
(Score: 3, Informative) by takyon on Monday May 28 2018, @07:59AM
https://www.nature.com/articles/s41467-018-04177-w [nature.com]
https://www.annualreviews.org/doi/10.1146/annurev-fluid-010313-141255 [annualreviews.org]
Parentheses are valid URL characters. Wikipedia uses them pretty often. [wikipedia.org]
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by VLM on Monday May 28 2018, @01:26PM
This seems a riff off bullet vs tissue dynamics research with the addition of buoyancy and much slower speeds. Nothing in the refs to indicate that, but it is kinda a cousin of that research.