Interval order: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
en>Lerutit
m added reference
en>BG19bot
m WP:CHECKWIKI error fix for #61. Punctuation goes before References. Do general fixes if a problem exists. - using AWB (10511)
 
Line 1: Line 1:
The '''Stimpmeter''' is a device used to measure the speed of a [[golf course#Putting green|golf course putting green]] by applying a known force to a [[golf ball]] and measuring the distance traveled in feet.
Ed is what individuals contact me and my wife doesn't [http://cpacs.org/index.php?document_srl=90091&mid=board_zTGg26 best psychic readings] chat online - [http://www.weddingwall.com.au/groups/easy-advice-for-successful-personal-development-today/ http://www.weddingwall.com.au/groups/easy-advice-for-successful-personal-development-today], like it at all. She is really fond of caving but she doesn't have the time recently. Distributing production is exactly where my main earnings arrives from and it's something I truly enjoy. For a while I've been in Mississippi but now I'm considering other choices.<br><br>Feel free to surf to my weblog psychics online ([http://c045.danah.co.kr/home/index.php?document_srl=1356970&mid=qna danah.co.kr])
 
==History==
It was designed by golfer Edward S. Stimpson, Sr. in 1935.<ref name="gd">{{cite journal | journal = Golf Digest | author = Frank Thomas | date = October 2001 | title = Equipment Extra: Eddie Stimpson's slant on putting }}</ref>  The [[Massachusetts]] state amateur champion and [[Harvard Crimson|Harvard]] golf team captain, Stimpson was a spectator at the [[1935 U.S. Open (golf)|1935 U.S. Open]] at [[Oakmont Country Club|Oakmont]] near [[Pittsburgh]], where the winning score was 299 (+11). After witnessing a putt by a top professional ([[Gene Sarazen]]) roll off a green, Stimpson was convinced the greens were unreasonably fast, but wondered how he could prove it. He developed a device, made of wood, now known as the Stimpmeter, which is an angled track that releases a ball at a known velocity so that the distance it rolls on a green's surface can be measured.<ref name=rdgtgr>{{cite news|url=http://news.google.com/newspapers?id=XbINAAAAIBAJ&sjid=GXIDAAAAIBAJ&pg=6316%2C551978 |newspaper=Pittsburgh Post-Gazette|last=Dvorchak|first=Robert|title=Reading the greens|date=June 13, 2007|page=E-6}}</ref>
 
In 1976 it was redesigned from [[aluminum]] by Frank Thomas of the [[United States Golf Association]] (USGA). It was first used by the USGA during the [[1976 U.S. Open (golf)|1976 U.S. Open]] at Atlanta and made available to golf course superintendents in 1978. The 1976 version is painted green.
 
In January 2013, the USGA announced a third generation device based on work by Steven Quintavalla, a senior research engineer at the USGA labs.<ref name=Newport20130125>{{cite journal |author=John Paul Newport |date=January 25, 2013|title=Ta-Da! Stimpmeter Makeover |journal=Golf Journal (A version of this article appeared January 26, 2013, on page A16 in the U.S. edition of The Wall Street Journal, with the headline: Ta-Da! Stimpmeter Makeover.)|url=http://online.wsj.com/article/SB10001424127887324539304578263953206840258.html?mod=WSJ_hp_editorsPicks_2 }}</ref> A second hole in this version enables the option of a shorter run-out.<ref name=Newport20130125 /> This version is painted blue, and is manufactured to a higher [[engineering tolerance]] to improve [[accuracy and precision]].<ref name=Newport20130125 />
 
Official USGA stimpmeters are not sold to the public.<ref name="gd"/>
 
==Description==
The 1976 device is an extruded aluminum bar, {{convert|36|in|cm}} long and {{convert|1.75|in|cm}} wide, with a 145° V-shaped groove extending along its entire length, supporting the ball at two points, {{convert|0.50|in|cm|2|abbr=on}} apart. It is tapered at one end by removing metal from its underside to reduce the bounce of the ball as it rolls onto the green. It has a notch at a right angle to the length of the bar {{convert|30|in|cm}} from the lower tapered end where the ball is placed. The notch may be a hole completely through the bar or just a depression in it. The ball is pulled out of the notch by gravity when the device is slowly raised to an angle of about 20°, rolling onto the green at a repeatable velocity of {{convert|6.00|ft/s|m/s|abbr=on}}.<ref>Brian W. Holmes, [http://adsabs.harvard.edu/abs/1986PhTea..24..401H "Dialogue concerning the Stimpmeter"], ''The Physics Teacher'' '''24'''/7 (1986) 401–404.</ref> The distance travelled by the ball in [[foot (length)|feet]] is the 'speed' of the putting green. Six distances, three in each of two opposite directions, should be averaged on a flat section of the putting green. The three balls in each direction must be within {{convert|8|in|cm}} of each other for USGA validation of the test.<ref>[http://www.usga.org/course_care/articles/management/greens/Stimpmeter-Instruction-Booklet/ USGA Stimpmeter Instruction Booklet]</ref><ref>[http://probablegolfinstruction.com/Stimpmeter.htm Stimpmeter — Measure putting green speed]</ref>
 
==Sloped greens==
One problem is finding a near level surface as required in the USGA handbook. Many greens cannot be correctly measured as you cannot find an area where the measured distance or green speed in opposing directions is less than a foot, particularly when they are very fast requiring a very long level surface.  A formula, based on the work of [[Isaac Newton]], as derived and [[Verification and validation|extensively tested]] by A. Douglas Brede, solves that problem. The formula is:
:<math>\frac{2\times S\uparrow \times\ S\downarrow}{S\uparrow +\ S\downarrow}</math>
(where S↑ is speed up the slope and S↓ is speed down the slope)
eliminates the effect of the slope and provides a true green speed even on severely sloped greens.<ref>A. Douglas Brede (November 1990). {{PDFlink|[http://gsr.lib.msu.edu/1990s/1990/901110.pdf Measuring green speed on sloped putting greens]}}</ref>
 
==Recommendations==
The [[United States Golf Association|USGA]] stimpmetered putting greens across the country to produce the following recommendations:<ref name="gd" />
 
{|class=wikitable
!&nbsp;Speed&nbsp;!!Length
|-
|align=center|Slow || align=center|&nbsp;{{convert|4.5|ft|1}}&nbsp;
|-
|align=center|Medium || align=center|&nbsp;{{convert|6.5|ft|1}}&nbsp;
|-
|align=center|Fast || align=center|&nbsp;{{convert|8.5|ft|1}}&nbsp;
|-
|}
 
For the [[U.S. Open (golf)|U.S. Open]], they recommend:<ref name="gd" />
 
{|class=wikitable
!&nbsp;Speed&nbsp;!!Length
|-
|align=center|Slow || align=center|&nbsp;{{convert|6.5|ft|1}}&nbsp;
|-
|align=center|Medium || align=center|&nbsp;{{convert|8.5|ft|1}}&nbsp;
|-
|align=center|Fast || align=center|&nbsp;{{convert|10.5|ft|1}}&nbsp;&nbsp;
|-
|}
 
The greens at [[Oakmont Country Club]] (where the device was conceived) are some of the fastest in the world, with readings of {{convert|13|–|15|ft|1}}.<ref name = "ppg06-07">{{cite news | title = Oakmont: Rock & roll (& roll & roll & roll) nightmare | work = [[Pittsburgh Post-Gazette]] | url = http://www.postgazette.com/pg/07161/792746-382.stm | date = 2007-06-10 | accessdate = 2007-06-10}}</ref>
 
== References ==
{{reflist}}
 
== External links ==
*[http://www.csgnetwork.com/stimpmetercalc.html A Better Stimpmeter And Calculator. CSG, Computer Support Group, Inc. and CSGNetwork.Com]
*[http://www.putting-greens.com/stimpmeter.html How to build your own Stimpmeter]
*[http://cp1302ger.wordpress.com/2007/10/03/the-stimpmeter/ The Stimpmeter by the Rambling Man] (with a picture)
*{{PDFlink|[http://turf.lib.msu.edu/1980s/1983/830316.pdf Up with the Stimpmeter by Stanley J. Zontek]|566 KB}}
*{{PDFlink|[http://turf.lib.msu.edu/1980s/1981/810328.pdf The Stimpmeter – A management tool by Patrick M. O'Brien]|457 KB}}
*{{PDFlink|[http://turf.lib.msu.edu/1990s/1997/970312.pdf Green speed physics by Authur P. Weber]|901 KB}}
*{{PDFlink|[http://archive.lib.msu.edu/tic/mitgc/article/200270.pdf Utilizing the Stimpmeter for its intended use by Michael Morris]|256 KB}}
 
[[Category:Golf equipment]]

Latest revision as of 07:37, 11 December 2014

Ed is what individuals contact me and my wife doesn't best psychic readings chat online - http://www.weddingwall.com.au/groups/easy-advice-for-successful-personal-development-today, like it at all. She is really fond of caving but she doesn't have the time recently. Distributing production is exactly where my main earnings arrives from and it's something I truly enjoy. For a while I've been in Mississippi but now I'm considering other choices.

Feel free to surf to my weblog psychics online (danah.co.kr)