Started contributing to Wikipedia (in earnest) June 2006. So far I have mainly contributed (and initiated) bridge articles, and math / physics stuff. I have also written a few backgammon and poker articles. July 2006 I started my biggest Wiki-project so far: compiling a comprehensive list of optimal plays for the various suit combinations that occur in the game of bridge. (See, however, the section "Beware of OR-fundamentalists" below.)

I am a starter and much less a completer. As I have strong faith in the 'wiki process', I experience little thresholds in initialising new articles. I do post immature articles and love to see these grow and improve thanks to your contributions. When an article is in an early stage of development, I am less interested in details, spelling, lay-out, formatting, etc. This 'slopiness' does not mean that I have any tolerance for content that is factually incorrect.


I participate in WikiProject Contract bridge, WikiProject Board and Table Games, WikiProject Mathematics, and WikiProject Physics.

Articles I've createdEdit

In order of creation. The bold titles refer to contributions that have escaped 'stub-status':

Rubensohl, Muiderberg convention, Lionel convention, Crash (convention), Gardener 1NT, Raptor convention, Ghestem, Par contract (redirected), Bep Vriend , Berry Westra, Overcall, Suit combinations, Pass-or-correct bid, Bauke Muller, BBGKY hierarchy, Green, Herbert (redirected), Arnold's cat map, Gingerbreadman map, Area-preserving maps (redirected), Last Train, Fred Gitelman, Jeff Rubens, Geir Helgemo, Blotto games, Conway puzzle, Slothouber-Graatsma puzzle, Conway sequence, Heronian mean, Forcing bid, Fourth suit forcing convention (redirected), Forcing pass, Principle of fast arrival, Bergen raises, Reverse bid (redirected), Bridge magazines, Grosvenor gambit, Archie's law, Bedlam cube, Fulvio Fantoni, Claudio Nunes, Fantunes, Piotr Gawrys, Jacek Pszczola, Michal Kwiecien, Adam Zmudzinski, Leaping Michaels, World Team Olympiad, World Open Pairs Championship, World Bridge Championships, World Mixed Pairs Championship, Romex system, Bridge probabilities, Tempo (bridge), Suit combinations - T missing, Suit combinations - J missing, Suit combinations - KT missing, Three suiter, Balanced hand, Boring club, Single suiter, Ekren convention, Computer bridge, Kit Woolsey, Philip Vischjager, Balancing (bridge), Pierre Ghestem, John R. Crawford, List of all-rounders in games of skill, Backgammon opening theory, Backgammon glossary (moved to:, Backgammon notation, Bill Robertie, Billy Eisenberg, Heinz mean, Penney's game, Jimmy Fricke, Comfy Canapé, Subtract a square, Grundy's game, Nontransitive game, Traveler's dilemma, Volunteer's dilemma, Kobon triangle problem, Moving sofa problem, Robbins constant, Mike Cappelletti, Richard Hutten, Kunsthal, Frits Goldschmeding, Princess and monster game, Centraal Museum, List of Dutch by net worth, Narayana number, Klaus-Michael Kühne, Gerrit Krol, P.C. Hooft Award, Bunyakovsky conjecture, Erdős–Anning theorem, Erdős-Diophantine graph, Rubens advances, Wereldhave, Feynman checkerboard, Kepler triangle, Surface of constant width, Bicone, Almost integer, Chicken McNuggets problem (merged into Coin problem), Nonhypotenuse number, Norman four notrump, San Francisco convention, Jorge Pan, Rolf Slotboom, Hans Melchers, Milheeze, Ouzo effect, Namyats, Willem Abraham Wythoff, Quantum pseudo-telepathy, Horsepower-hour, Edwin F. Taylor, Theodore Jacobson

Beware of OR-fundamentalistsEdit

Some Wikipedia editors seem to take the No original research policy to a next level. According to them, any results obtained with a computer program and not published in the open literature, should not appear in Wikipedia. That also holds true for results obtained with a computer program extensively verified against results that are published.[1] As a consequence of this OR-fundamentalism, I had to stop the project Suit Combinations. Most likely, the various articles containing tables of suit combinations (see e.g. Suit combinations - K10 missing) will disappear. I will try to safeguard the main article Suit combinations, but currently it seems that even this article is under attack.

Personally, I strongly feel that the group of OR-fundamentalists are losing sight of the original intentions[2] of the no-OR policy, and are pushing Wikipidia in a wrong direction. However, I don't have the time nor the energy to keep combatting this. Let's see how thing develop. JocK 20:26, 28 April 2007 (UTC)

  1. ^ Yes, that indeed means that you would not be allowed to include in a Wikipedia article - say - the result 2,007*2,007 = 4,028,049, in case you have obtained this result in Excel and you can't find a reputable source for this specific multiplication result. Your argument that you have tested your Excel worksheet against published results for all squares up to 100*100 will not impress them...
  2. ^ Wikipedia's co-founder, Jimbo Wales, has described the origin of the original research policy as follows: "The phrase 'original research' originated primarily as a practical means to deal with physics cranks, of which of course there are a number on the Web. The basic concept is as follows: It can be quite difficult for us to make any valid judgment as to whether a particular thing is true or not. It isn't appropriate for us to try to determine whether someone's novel theory of physics is valid; we aren't really equipped to do that. But what we can do is check whether or not it actually has been published in reputable journals or by reputable publishers. So it's quite convenient to avoid judging the credibility of things by simply sticking to things that have been judged credible by people much better equipped to decide. The exact same principle will hold true for history." (Wales, Jimmy. "Original research", December 3, 2004)

Did you know...Edit

  On 31 July, 2006, Did you know? on Wikipedia's Main Page was updated with a fact from the article Computer bridge, which I created.
  On 7 August, 2006, Did you know? on Wikipedia's Main Page was updated with a fact from the article Backgammon opening theory, which I created.
  On 2 february, 2008, Did you know? on Wikipedia's Main Page was updated with a fact from the article Ouzo effect, which I created.
  On 4 December, 2008, Did you know? was updated with a fact from the article Quantum pseudo-telepathy, which I created.

And did you know ... that you can also suggest interesting facts from recently created articles?

Wikipedia, its strengths and weaknessesEdit

An excellent essay on the history of Wikipedia, and how Wikipedia captures history: Roy Rosenzweig in The Journal of American History, Vol. 93, Number 1 (June, 2006), p. 117-46.

Interesting User-pagesEdit

Views of spacetime along the world line of a rapidly accelerating observer in a Newtonian universe. The events ("dots") that pass the horizontal line are the current events visible to the observer.
Views of spacetime along the world line of a rapidly accelerating observer in a relativistic universe. The events ("dots") that pass the two diagonal lines in the bottom half of the image (the past light cone of the observer in the origin) are the events visible to the observer.
  • User:Cyp : Some more polyhedra. More interestingly, Cyp also appears to be the creator of two beautiful animations on Galilean and Lorentz transformations - see animations to the left and right:

Vertical direction indicates time. Horizontal indicates distance (only one spatial dimension is taken into account), and the thick dashed line is the spacetime trajectory ("world line") of the observer. The small dots indicate specific (past and future) events in spacetime.

The slope of the world line (deviation from being vertical) gives the relative velocity to the observer. Note how in both pictures the view of spacetime changes when the observer accelerates. In the Newtonian description these changes are such that time is absolute: the movements of the observer do not influence whether an event occurs in the 'now' (i.e. whether an event passes the horizontal line through the observer). However, in the relativistic description the observability of events is absolute: the movements of the observer do not influence whether an event passes the light cone of the observer. Notice that with the change from a Newtonian to a relativistic description, absolute time is no longer applicable: events move up-and-down in the figure depending on the acceleration of the observer.

Places I've been toEdit

I've worked and lived in Europe, Asia, Africa and North America. Including visits and holidays, I have been to 34 nations spread over the same four continents:


As part of my Wikipedia activities, I try to expand (or create) Wikipedia articles pertaining to the countries I visited.

Me and my activities in nine userboxesEdit

  JocK enjoys playing bridge.
 JocK comes from the Netherlands.
inclJocK is a Wikipedia inclusionist.
ORThis user combats no-OR_fundamentalism.
 This user is a physicist.
 This user enjoys playing poker.