Rising fastball

[NIump50]

Originally Posted by BigUmp56

From the Wikepedia:


The fastball is the most common type of pitch in baseball. Some "power" pitchers, like Randy Johnson and Billy Wagner, can throw it 95-100 mph (150-160 km/h), and rely on this speed to prevent the ball from being hit. Others throw more slowly but put movement on the ball or throw it on the outside of the plate where the batter cannot easily reach it. The effect of a faster pitch can sometimes be achieved by minimizing the batter's vision of the ball before its release. The result is known as an "exploding fastball": a pitch that seems to arrive at the plate quickly despite its low velocity. Fastballs are usually thrown with backspin, so that the Magnus effect creates an upward force on the ball, causing it to fall less rapidly than might be expected. A pitch on which this effect is most marked is often called a "rising fastball", as the ball appears to rise to the batter. Colloquially, use of the fastball is called throwing heat or putting steam on it, among many other variants.



From Popular Mechanics:




The Myth Of The Rising Fastball

Years ago, baseball players and fans commonly believed that it was possible to throw a rising fastball--a pitch that would curve upward or hop as it approached the batter. This could be done, it was thought, by gripping the baseball across the seams and releasing the pitch with a wrist snap that would impart a pronounced backspin on the ball. Although they could not explain why it happened, pitchers, batters and catchers were convinced that if the pitch were thrown at high speed--over 90 mph--it would rise as it crossed the plate, causing the batter to misjudge the trajectory and swing under the ball. They were certain the ball rose because they could see it rise.

As a longtime baseball fan and a physicist specializing in the physics of sports, I was curious to find out whether the rising fastball was for real. After all, a baseball must obey the laws of physics, and there was a well-established theory and sufficient data available to allow me to calculate the aerodynamic forces on a baseball in flight. The basic principles are relatively simple. After the ball leaves the pitcher's hand, it is subject to just three forces: gravity (equal to the weight of the ball) pulling it vertically downward; aerodynamic drag, created by the collision of the ball with the surrounding air, which reduces its forward speed; and what is known as the Magnus force, generated by the interaction of the spinning surface of the ball with the air. The ball generates a low-pressure wake behind it as it moves through the air, but if the surface is spinning, the wake is deflected sideways. According to Newton's law of action and reaction, if the ball deflects the air to one side, the air will push the ball in the opposite direction. The Magnus force always acts perpendicular to the path of the ball, deflecting it sideways according to the direction of spin. It is this force that allows pitchers to throw a repertoire of breaking balls--curveballs, sliders, sinkers, etc.--by adjusting the rate and direction of the spin on the ball along with the speed and location of the pitch. To throw a rising fastball, the Magnus force must be directed upward, opposing the pull of gravity, and this can be achieved by throwing the ball with backspin. If the Magnus force is greater than the weight of the ball, then the net force on the ball will cause it to rise.

When I ran computer simulations of pitches, I made some interesting discoveries. I learned that over the standard pitching distance of 60 ft. 6 in., a ball loses about 9 percent of its initial speed due to aerodynamic drag--thus a pitch launched at 90 mph will have slowed to 81 mph when it reaches the batter. The pitch takes only about 0.44 second to cover the distance. During this interval the ball falls about 3 ft. due to the pull of gravity. A batter has less than half a second to judge the trajectory of the ball, decide whether to swing, and then bring his bat around to the projected point of contact. Hitting a baseball at the major league level, I discovered, is a truly remarkable feat.

Most significantly, I discovered that in order for the ball to truly rise in flight--for the Magnus force to exceed the weight of the ball--the pitch would have to be launched with a backspin of more than 3600 rpm. This is far beyond the capacity of any major league pitcher. High-speed photography shows that spin rates of about 1800 rpm are the best that can be achieved. Thus, it is not humanly possible to throw a true rising fastball. With the ball spinning at 1800 rpm and traveling at 90 mph, the Magnus force retards the vertical drop by a little more than a foot. Instead of dropping 3 ft. vertically on its way to the plate, the ball drops slightly less than 2 ft. I concluded that the rising fastball is an optical illusion. The ball appears to rise only because it doesn't fall as much as the batter expects it to--in other words, the ball rises only in relation to the batter's expectations.

Over time, a number of other scientists have verified my results. The most convincing confirmation has come from real-time tracking of baseball pitches using multiple video cameras and rapid computerized reconstruction of the trajectories. To the best of my knowledge, no one has ever recorded a fastball rising as it crosses the plate.
--Peter J. Brancazio
Professor Emeritus of Physics
Brooklyn College, The City University of New York



You can see for yourself that it's impossible for a pitched baseball to rise by doing a simulation at this link. All of the advanced calculations are done for you. However feel free to input as many relevant variables as you'd like.


http://www.csc.calpoly.edu/~nterrell...eport.html#use


In the past four months as this debate has raged I've done mathematical calculations myself to prove the impossibility of a baseball thrown overhand rising, posted studies by noted physicists and image physiologists. Yet for some reason I can only attribute to stubborness there are at least two of you who feel you know better. This will hopefully be my last post on this subject. Feel free to believe what ever science fiction you want to. The fact is, and I do mean fact, that it's impossible for a baseball thrown overhand to escape it's initial velocity vector.



Tim.

Did you read the quote from physicist Robert Adair?
He says not even Einstien can predict the movement of a baseball and that
the equations to predict the movement of a baseball cannot be solved.
When the basic rules of physics are applied to a baseball they are not able to calculate the flight of the ball.
Are these physicists in your post smarter than Adair? Maybe yes maybe no.
maybe they're just postulating. Maybe it's not as exact a science as you make it out to be.

A Google search on the term "rising fastball" reveals dozens of articles all attesting to the fact that the rising fastball is an optical illusion. To the exquisitely trained eyes of a top-flight batter or catcher, the ball appears to rise because it does not fall as much as it would without the backspin.
An 85 mph fastball doesn't have backspin?
And again I ask
Based on the reasons given for why a ball 'appears' to rise, why does an 85mph fastball never 'appear' to rise.
The logic behind optical illusion makes no sense.

Please explain

[BigUmp56]

I'll not do the footwork again. There was an exact study presented here several months ago that was conducted by the physics department at Arizona State University. In the study they used several different modems whereby a baseball could be projected with exact measured speed and spin ratios. They concluded that for Bernoulli's principle to apply the rotation of the ball would have to exceed 3600 rpm. Then through more extensive research they concluded that the highest possible rotation placed on a baseball by a human while throwing it would reach only 1800 rpm. Adair was correct that Einstein couldn't predict all the pertinent forces that would need to be applied to prove exact movement. However, Einstein not only did no such study that I'm aware of, if he did he would not have had the advanced mesurement technology available to him that the physicists did who conducted the ASU study.


Tim.