Sports that I either actively participate in or would like to some day.
I cycle 16Km off-road (to and from work) on a daily basis. Cycling is very good for your health and is actually enjoyable sometimes (the times you are not too tired)
Some repair guides for your usual bike ailments
You may need to do this ugly job if crank-axle bearings need replacement or the system needs to be tightened up, maintained or just lubed up.
those who know me well also know that I am a Physics buff. Every now and then I just have to delve into the physics of things. I am sure I am not the only one around here who loves this stuff, especially given the fact that one of the list's members holds a PhD in Physics and has several years of experience in actual research in laser technology. In fact he was once lightly wounded by a laser - or was it phaser? :) Makis, can you end the confusion here?
Anyway, something that I had been meaning to do for some time was to look into the physics of sailboats as there are concepts and facts there that are quite simply fascinating and amazing. For instance: How can sailboats sail upwind? How can sailboats sail faster than the wind? What does the term "she makes her own wind, laddie" refer to?
A concise and fairly accurate primer into the physics of sailing is here (although it does downplay the significance of the Bernoulli effect which in some configurations can be very important indeed and is what makes a boat "generate its own wind" and also what makes footballs follow elliptical paths)
http://www.phys.unsw.edu.au/~jw/sailing.html
after digesting this you can do some quite cool virtual sailing here:
http://www.nationalgeographic.com/volvooceanrace/interactives/sailing/index.html
Pretty much after this all you need to actually sail on your own is some practical skills priming here:
http://www.sailingusa.info/sailing_primer.htm
Now, go rent yourself a sailboat and after a couple of rides with an instructor you should be able to take her on your own.
Now about the bernoulli effect which is quite fascinating and among other things it is also the reason planes fly.
http://www.rz.uni-frankfurt.de/~weltner/Flight/PHYSIC4.htm
The bernoulli effect is very important in sailing as well. Some people have tried (quite successfully) to boost its effect and make ships that sail using the bernoulli effect as their main or only means of propulsion. The first ship I know of that did that is Flettner's Rotorship:
http://www.efluids.com/efluids/gallery/flettner_rotorship.html
An easy to set up proof of concept:
http://www.mip.berkeley.edu/physics/C+25+0.html
An even easier one that I just thought of:
- Spin a spinning top
- Blow on it
- Watch it predictably move to the side but always toward the right or the left (depending on whether the top spins clockwise ot counter-clockwise)
* If you try this, tell me if it actually worked! :)
A more modern aproach to tapping the bernoulli effect is Cousteau's Turbosail (first implemented on a ship called "Alcyone", and frankly looking quite cool):
alcyone: http://www.dolphinlog.org/alcyone.htm
Stuff about Tennis
The ATP defines the ATP Race as "an easy-to-understand, simple-to-follow annual race from season start to season end. Every player starts at zero at the beginning of the year and the player who accumulates the most points by season's end is the World Number 1" and claims that the Race "is the mathematical method of ranking male professional tennis players on a calendar-year basis."
According to the ATP: "Every player, regardless of his performances in the previous year, starts with zero points. Players count 18 performances in their INDESIT ATP 2005 Race total. Players eligible to enter the Grand Slams and Tennis Masters Series events must count those events and their best five other results from the International Series events. The Tennis Masters Cup will count as an additional 19th tournament for the eight players who qualify."
| Event category | Number | Prize money (USD) | Ranking points | Governing body |
|---|---|---|---|---|
| Grand Slams | 4 | 6,784,000 to 9,943,000 | 1,000 | ITF |
| Tennis Masters Cup | 1 | 4,450,000 | 750 | ATP & ITF |
| ATP Masters Series | 9 | 2,450,000 to 3,450,000 | 500 | ATP |
| ATP International Series Gold | 9 | 755,000 to 1,426,250 | 350 | ATP |
| ATP International Series | 43 | 416,000 to 1,000,000 | 250 | ATP |
| ATP Challenger Series | 115 | 25,000 to 150,000 | 80 | ATP |
| Futures | 420 | 10,000 and 15,000 | - | ITF |
| Tournament category | Total financial commitment |
W | F | SF | QF | R16 | R32 | R64 | R128 | Additional qualifying points |
|---|---|---|---|---|---|---|---|---|---|---|
| Grand Slam | 200 | 140 | 90 | 50 | 30 | 15 | 7 | 1 | 3 | |
| ATP Masters Series | 100 | 70 | 45 | 25 | 15 | 7 | 1(3) | (1) | 3* | |
| International Series Gold | $1,000,000 | 60 | 42 | 27 | 15 | 5 | 3 | 1 | 2* | |
| International Series Gold | $800,000 | 50 | 35 | 22 | 12 | 5 | 3 | 1 | 2* | |
| International Series | $1,000,000 | 50 | 35 | 22 | 12 | 5 | 3 | 1 | 2* | |
| International Series | $800,000 | 45 | 31 | 20 | 11 | 4 | 2 | 1 | 2* | |
| International Series | $600,000 | 40 | 28 | 18 | 10 | 3 | 1 | 1 | ||
| International Series | $400,000 | 35 | 24 | 15 | 8 | 3 | 1 | 1 | ||
| Tennis Masters Cup | 150 | if undefeated (20 for each round robin match win, +40 for a semifinal win, +50 for winning finalist) |
||||||||
The ATP defines the ATP Entry Ranking as "the objective merit-based method used for determining qualification for entry and seeding in all Tournaments for both singles and doubles, except as modified for World Team Championship, World Doubles Championship and Tennis Masters Cup...The Entry Ranking period is the immediate past 52 weeks, except for: the Tennis Masters Cup, which is dropped on the Monday following the last ATP event of the following year; Futures Series Tournaments, that are only entered into the System on the second Monday following the Tournament's week. Once entered, all Tournaments, except for the Tennis Masters Cup, remain in the System for 52 consecutive weeks."
The ATP explains that the reason behind continuing with a 52-week rolling system is "to determine seedings and tournament entry status [as] it is not practical to use the INDESIT ATP Race." It further notes that "The Race, while indicating the hottest players in the game at any stage, does not necessarily indicate an overall standing in the game. This is especially valid at the start of the year when early tournament winners may well be leading the Race but are not yet established top players for the purposes of seeding and tournament entry."
In addition to the points allocated above, points are allocated to losers at Grand Slam, Tennis Masters Series and International Series Gold Tournaments qualifying events in the following manner:
Grand Slams: 8 points for a last round loser, 4 points for a second round loser
Tennis Masters Series: 8 points for a last round loser(*), 1 point for a first round loser
International Series Gold: 5 points for a last round loser(*), 1 point for a first round loser,
(*): 3 points only if the Main Draw is larger than 32 (International Series Gold) or 64 (Tennis Masters Series).
From wikipedia.org entry on "Tennis", simplified and with further explanatory comments...
A tennis match usually comprises one to five sets. A set consists of a
number of games, and games, in turn, consist of points.
A game consists of a sequence of points played with
the same player serving, and is won by the first player to have won at least
four points and at least two points more than his opponent. The running score of
each game is described in a manner particular to tennis: scores of zero to three
points are described as "love" (or zero), "fifteen,"
"thirty," and "forty" respectively. When at least three points
have been scored by each side and the players have the same number of points,
the score is "deuce." When at least three points have been scored by each
side and a player has one more point than his opponent, the score of the game is
"advantage" for the player in the lead. During informal games,
"advantage" can also be called "ad in" or "ad out", depending on whether the
serving player or receiving player, respectively, is ahead.
A game point occurs in tennis whenever the player who is in the lead
in the game needs only one more point to win the game. The terminology is
extended to sets (set point), matches (match point), and even championships
(championship point). For example, if the player who is serving has a score of
40-love, he has a triple game point (triple set point, etc.).
A break point occurs if the receiver, not the server, has a game
point. It is of importance in professional tennis, since service
breaks happen less frequently with professional players. It may happen that
the player who is in the lead in the game has more than one chance to score the
winning point, even if his opponent should take the next point(s). For example,
if the player who is serving has a score of 15-40, the receiver has a double
break point. Should the player in the lead take any one of the next two points,
he wins the game.
A set consists
of a sequence of games played with service alternating between games, ending
when the count of games won meets certain criteria. Typically, a player wins a
set when he wins at least six games and at least two games more than his
opponent. When each player has won six games a tiebreaker
is played. A tiebreaker, played under a separate set of rules, allows one player
to win one more game and thus the set, to give a final set score of 7-6. Only in
the final sets of matches at the Australian Open, the French Open, Wimbledon,
Davis Cup, and Fed Cup are tie-breaks not played.
Matches consist of an odd number of sets, the match winner being the player who wins
more than half of the sets. The match ends as soon as this winning condition is
met. Some matches may consist of five sets (the winner being the first to win
three sets), while most matches are three sets (the winner being the first to
win two sets).
Another, however informal, tennis format is called "Canadian doubles". This
involves three players, with one person playing against a doubles team. The
single player gets to utilize the alleys normally reserved only for a doubles
team. Conversely, the doubles team does *not* use the alleys when executing a
shot. The scoring is the same as a regular game. This format is not sanctioned
by any official body and is only played when a fourth player is not available
for normal doubles.
Wheelchair tennis can be played by able-bodied players as well as people who require a wheelchair for mobility. An extra bounce is permitted. This rule makes it possible to have
mixed wheelchair and able-bodied matches. It is possible for a doubles team to
consist of a wheelchair player and an able-bodied player (referred to as
"one-up, one-down"), or for a wheelchair player to play against an able-bodied
player. In such cases, the extra bounce is permitted for the wheelchair users
only.
There are three main types of court surface. Depending on the materials used,
each surface provides a difference in the speed and bounce of the ball, which in
turn can affect the level of play of individual players. The three most common
surfaces are:
Indoor courts are also used so play can continue year-round. Common indoor surfaces are hard, carpet, and clay.
A game consists of a sequence of points played with the same player serving, and is won by the first player to have won at least four points and at least two points more than their opponent. The half of the court (across the long side of the court) used for service, alternates between sides, beginning with the right-hand half (from the perspective of the player serving), known as the deuce court, and continuing with the left-hand side, known as the advantage court (advantage because for a right-handed player service is easier on that side).
At a score of 6-6, a set is often determined by one more game called a "twelve point tie-break." Points are counted using ordinary numbering. The set is decided by the player who wins at least seven points in the tie-break and also has two points more than his opponent. For example, if the score is 6 points to 5 points and the player with 6 points wins the next point, he wins the tie-break and the set. If the player with 5 points wins the point, the tie-break continues and cannot be won on the next point, since no player will be two points ahead of his opponent. Since only one more game is played to determine the winner of the set, the score of the set is always 7-6 (or 6-7). Sometimes the tie-break points are also included, for example 7-6 (7-4). Another way of listing the score of the tie-break is simply to list the loser's points. For example, if the score is listed as 7-6 (8), the tie-break score was 10-8 (since 8 is the loser's points, and the winner must win by two points).
The player who would normally be serving after 6-6 is the one to serve first in the tie-break, and the tie-break is considered a service game for this player. The server begins his service from the deuce court and serves one point. After the first point, the serve changes to the first server's opponent. Each player then serves two consecutive points for the remainder of the tie-break. Further, the first of each two-point service starts from the server's advantage court and ends in the deuce court. After every six points, the players switch ends of the court. At the end of the tie-break, the players switch ends of the court again, since they have played an odd number of games in the set.
In this excerpt from The Courts of Babylon, ace tennis writer Peter Bodo describes how tournament fields are selected from entry rankings, wild cards, and qualifiers.
p. 68-69
This is how the tournament system works in the pro era: Grand Slam tournaments and ATP Tour or WTA Tour events accept players on the basis of their world rankings, which are generated by sophisticated computer programs. The higher a player's ranking, the better his chance of being accepted into the field, or "draw." The only exceptions to that rule are qualifiers and wild cards (more about them later) who can take places held open after the main draw has been filled by the highest-ranked players seeking entry.
A two-week Grand Slam event has a draw of 128, while a typical one-week tour event has a draw of 32. Of those 128 places in a Grand Slam draw, 16 are reserved for qualifiers and 8 for wild cards [these numbers have now been adjusted slightly to enter more wild cards, or players in exceptional circumstances, so there are slightly fewer "automatic" rank based openings], leaving 104 places that are filled solely in order of world rankings-- rankings that are generated by a complex formula worked out to rate a player's performance over the previous twelve months. Events with smaller draws have proportionately fewer places for qualifiers and wild cards.
Thus, the number seventy-five player in the world is assured of a place in the draw of Wimbledon, but whether or not he is "straight in" in a popular one-week ATP Tour event with a draw of thirty-two is questionable. It all depends on the cutoff number, which is a function of how many players want to play the event and how high their rankings are. During a week when there are two or three tournaments in progress in different parts of the world, the number seventy-five player has a good chance of getting into an event with a draw of thirty-two, even though he is not one of the top thirty-two players in the world. It all depends on how many of the players ranked above him are playing elsewhere or not at all.
So the maximum number of players in any tournament is 128, yet the ATP and WTA tours rank 500 players each [over a thousand each now], and behind them are thousands of other players who would love to get a shot at playing the pro tour. That's where qualifiers, wild cards, and the plethora of "satellite" circuits and Challenger tournaments come into it. Theoretically, anybody can have a wild card into Wimbledon or the U.S. Open, and that includes you and me. Wild cards are rendered at the discretion of the promoter or tournament director, but they are usually given to promising junior players, aging champions who remain gate attractions despite being in semi or full retirement, and quality players who have lost their rankings because of unusual circumstances such as a long layoff because of injury. The competition for wild cards is fierce. Promoters use them to enhance the marquee value of their events. Player agents wheel and deal with promoters to get them for promising juniors, and each of those parties uses the wild cards as a tool for building credibility with the prodigy and his or her parents.
Qualifying is the real door to the big time for players who do not automatically earn entry into tournaments because their rankings are not high enough. The sixteen places reserved for qualifiers at Grand Slam events go to players who earn the berths in the qualifying event that immediately precedes the tournament. With five hundred players holding official rankings, the qualifying competitions can be fierce, but they enable a player to leapfrog over those ranked above him, right into the big time, if he or she has the game to do so.
from The Courts of Babylon: Tales of Greed and Glory in a Harsh New World of Professional Tennis Scribner; ISBN: 0684812967; June 1995, out of print usually available used from ABE Books or Amazon.com
Information above found at http://sports.quickfound.net/courts_of_babylon_tourneys.html
Information on Association of Tennis Professionals
Information on Women's Tennis Association