Featured Research

from universities, journals, and other organizations

Playing cricket: Physicists cast new light on spin-bowling

Date:
July 4, 2013
Source:
Institute of Physics (IOP)
Summary:
As the Ashes series gets underway next week, a pair of brothers from Australia have been exploring the physics behind the spin of a cricket ball. While physicists are much more accustomed to measuring the spin of electrons, protons and neutrons, physicists have now presented equations that govern the trajectory of a spinning ball as it moves through the air in the presence of a wind.

As the Ashes series gets underway next week, a pair of brothers from Australia have been exploring the physics behind the spin of a cricket ball.

While physicists are much more accustomed to measuring the spin of electrons, protons and neutrons, Garry and Ian Robinson, Honorary Visiting Fellows at the University of New South Wales and the University of Melbourne respectively, have presented equations that govern the trajectory of a spinning ball as it moves through the air in the presence of a wind.

Their paper has been published today, 5 July, in Physica Scripta -- a journal published by IOP Publishing on behalf of the Royal Swedish Academy of Sciences for the Science Academies and the Physical Societies of the Nordic Countries.

If the English and Australian cricketers are looking to take advantage of their results then they will be hoping that the unpredictable British weather brings plenty of wind throughout the five-game series, as the researchers have calculated that it can have a profound effect on the movement through the air of a spin-bowler's delivery.

According to the research, the presence of a cross-wind from either side of the cricket pitch can cause the spinning ball to either slightly "hold up" or "dip," depending on which direction the wind comes from and which way the ball is spinning. This therefore changes the point at which the ball pitches on the wicket.

Garry Robinson said: "Our results show that the effects on a spinning ball are not purely due to the wind holding the ball up, since a reversal of wind direction can cause the ball to dip instead. These trajectory changes are due to the combination of the wind and the spin of the ball.

"The effects of spin in the presence of a cross-wind, and how to fully exploit it, may or may not be completely appreciated by spin bowlers. Either way, we have provided a mathematical model for the situation, although the model of course awaits detailed comparison with observations."

As an example, the researchers show that when a 14 km/h cross-wind interacts with the spinning ball, the point at which it hits the ground can change by around 14 cm, which they believe may be enough to deceive a batsman.

The equations take into account the speed of the ball, gravity, the drag force caused by air resistance, and the Magnus or "lift" force, while at the same time incorporating the important effect of wind.

The Magnus force is a commonly observed effect, particularly in ball sports, when the spin of a ball causes it to curve away from its set path. This is observed in football when players purposely put spin on the ball to make it bend around a defensive wall.

Once the equations were constructed, they were numerically solved using a computer software program called MATLAB; the solutions were then used to create illustrative examples for cricket.

The researchers also show that a spinning cricket ball tends to "drift" in the latter stages of its flight as it descends, moving further to the off-side for an off-spinning delivery and moving further towards the leg-side for a leg-spinning delivery, effects which are well-known and regularly utilised by spin-bowlers.

"We hope that this work can be used to cast new light on the motion of a spinning spherical object, particularly as applied to cricket, whilst also stirring the interests of students studying differential equations," Garry continued.


Story Source:

The above story is based on materials provided by Institute of Physics (IOP). Note: Materials may be edited for content and length.


Journal Reference:

  1. Garry Robinson, Ian Robinson. The motion of an arbitrarily rotating spherical projectile and its application to ball games. Physica Scripta, 2013; 88 (1): 018101 DOI: 10.1088/0031-8949/88/01/018101

Cite This Page:

Institute of Physics (IOP). "Playing cricket: Physicists cast new light on spin-bowling." ScienceDaily. ScienceDaily, 4 July 2013. <www.sciencedaily.com/releases/2013/07/130704094920.htm>.
Institute of Physics (IOP). (2013, July 4). Playing cricket: Physicists cast new light on spin-bowling. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2013/07/130704094920.htm
Institute of Physics (IOP). "Playing cricket: Physicists cast new light on spin-bowling." ScienceDaily. www.sciencedaily.com/releases/2013/07/130704094920.htm (accessed July 30, 2014).

Share This




More Matter & Energy News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
China's Drone King Says the Revolution Depends on Regulators

China's Drone King Says the Revolution Depends on Regulators

Reuters - Business Video Online (July 30, 2014) Comparing his current crop of drones to early personal computers, DJI founder Frank Wang says the industry is poised for a growth surge - assuming regulators in more markets clear it for takeoff. Jon Gordon reports. Video provided by Reuters
Powered by NewsLook.com
3Doodler Bring 3-D Printing to Your Hand

3Doodler Bring 3-D Printing to Your Hand

AP (July 30, 2014) 3-D printing is a cool technology, but it's not exactly a hands-on way to make things. Enter the 3Doodler: the pen that turns you into the 3-D printer. AP technology writer Peter Svensson takes a closer look. (July 30) Video provided by AP
Powered by NewsLook.com
Climate Change Could Cost Billions, According To White House

Climate Change Could Cost Billions, According To White House

Newsy (July 29, 2014) A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins