Don’t mind me, just popping.

http://www.abc.net.au/science/articles/2012/05/30/3514434.htm

he widely-held belief that moisture in the air during humid conditions helps make a cricket ball swing has been clean bowled in a scientific study.

Swing bowling – when a delivery curves sideways in mid-air – has long been regarded as one of the game’s dark arts, not only deceiving hapless batsmen but also puzzling cricket-loving scientists.

Researchers from Britain’s Sheffield Hallam University and the University of Auckland in New Zealand reviewed scientific literature on the subject and conducted their own tests to try to get to the bottom of the mystery.

From the earliest studies of the phenomenon in the 1950s to the “seminal review of sports ball dynamics” by NASA scientist Rabindra Mehta in 1985, they found humidity was consistently cited as a crucial factor in achieving swing.

The researchers tested the theory using 3D laser scanners in an atmospheric chamber to measure the effect different humidity levels had on deliveries using balls which had been “aged” to simulate match conditions.

While altitude and the age of the ball both increased swing, the scientists did not discover any link between moisture levels in the air and sideways movement of the ball.

“This study shows that there is no direct or indirect manner in which humidity can significantly affect the ability of the bowler to make the ball swing,” they concluded in research published in the online journal Procedia Engineering this week.

“It is therefore logical to conclude that humidity may not have the significant influence on swing bowling that is widely assumed.”

Instead, the researchers put forward their own theory that cloud cover provided the ideal environment for swing bowling because it reduced turbulence in the air caused by heating from sunlight.

They say such still conditions meant the air surrounding the ball during the delivery was less likely to be disturbed, making it easier to produce the “asymmetrical” flight needed for swing bowling.

“What is clear is that the scientific community should turn their attention away from the question of humidity and focus their efforts to test the cloud cover hypothesis,” they says.

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I think that’s pretty cool! all up!

>>While altitude and the age of the ball both increased swing

They seem to be only considering reverse swing not conventional swing, a brand new ball will swing conventionally untill the seam is beaten down, reverse swing is a different kettle of fish and relies on different physics which involving turbulence over one side of the ball when it is old and roughed up on one side, remember a new ball swings a lot and it is shiney on both sides.
Then there is drift that spinners get, that is different again and it relies on the fast rotation of the ball, like a ping pong ball.

So they need to stipulate what type of swing they are trying to measure.

Another difference in the swing type is that medium pacers can swing the ball conventionally but to get the ball to go Irish it needs to be delivered quite fast.

Dropbear said:

Don’t mind me, just popping.

S’Ok. Welcome to the Darkside

>:->

Dropbear said:

The widely-held belief that moisture in the air during humid conditions helps make a cricket ball swing

Good to see some more serious scientific research going into one of the most important fields of human endeavour.

Don’t think the humidity aspect is going to news to anyone other than Tony Grieg and some on his mates though.

This from 1995:

http://web.archive.org/web/20070205230626/http://www.soest.hawaii.edu/GG/STUDENTS/jfoster/swing.html

No points for the thread title.

Something along the lines of “Fundamental NASA research shown to be flawed” would have been more catchy.

;-)

thread title seems matched to the content to me ..

http://www.celebritynetworth.com/richest-celebrities/

Ain’t the internet grand.

Opps sorry.

Dropbear said:

thread title seems matched to the content to me ..

You appear to have missed my intent. Never mind.

what’s the ‘cloud cover’ hypothesis?

never mind I re read it..

“Instead, the researchers put forward their own theory that cloud cover provided the ideal environment for swing bowling because it reduced turbulence in the air caused by heating from sunlight.”