Olympic Sports Science Friday: CURLING

oh yes sports fans. you know you like it.
as a girl growing up in Detroit, one could always find curling on CBC.
what a great sport...yelling at a rock, sweeping with a broom---it's like being a wife, no!?

Andy and the guys with fancy pants gave you the overview in the previous post. Here is a pretty cool website that explains all sorts of things like what's the sheet, the stone, the delivery and strategic rock placement.

The key though, is the turn of the rock and the sweeping.
SO, recall that the stone has a handle on it. By turning the handle prior to releasing it you can control if the rock in-turns or out-turns. If you are a righty, you turn the handle clockwise to get it to travel to the right of the sheet. A counter-clockwise turn will send the stone toward the left of the sheet.
Now, here's the fun part. As the rock slides across the ice, the front of the rock creates friction on the surface of the ice. That friction causes a slight melting of the ice leaving a small film of liquid which alters the contact of the stone on the ice.


For the curious---here are some references:

[1] "The Motion of a Culing Rock", Shegelski, Niebergall, and Walton,
CANADIAN JOURNAL OF PHYSICS, volume 74, pages 663-670, 1996.
[2] "The Motion of Rapidly Rotating Culing Rocks", Shegelski and
Niebergall, AUSTRALIAN JOURNAL OF PHYSICS, volume 52, pages 1025-1028, 1999.
[3] "The Motion of Rotating Cylinders Sliding on Pebbled Ice",
Shegelski, Niebergall, and Reid, CANADIAN JOURNAL OF PHYSICS, volume
77, pages 847-862, 1999.
[4] "The Motion of a Culing Rock: Inertial vs. Noninertial Reference
Frames", Shegelski and Reid, CANADIAN JOURNAL OF PHYSICS, volume 77,
pages 903-922, 1999.

By sweeping in front of the rock, you can generate more or less friction. The amount of heat generated by the sweeping depends on the amount of pressure applied and the vigour with which the sweeping motions occur. The faster and harder the sweeping....the more the friction...the more the heat...the more the melt....the longer the slide

I can't do any better than this:





TOO FREAKIN' COOL

The Expanding Universe

Warning: This has nothing to do with sports, but I thought it was a pretty cool description of mind blowing concept.

So you might imagine in your mind an infinite universe in which in the beginning, everything was close together.
Everything moves farther and farther apart, but it's just as infinite at the beginning as it is at the end.

If you don't want to sit through the class, you can borrow my notes....

Hail.

Wolverine vs Badger

Inter-species conflict.
Assumptions = Two very healthy adult males.

Weight: 40 pounds
Weapons: 38 Teeth and curved and semi-retractile claws.
Build: The Wolverine's head is broad and rounded, with small eyes and short rounded ears. The skull of the wolverine is robust; powerful jaw and associated musculature enable it to forage on frozen meat and bone.
Armor: Wolverine fur is typically a thick, glossy dark brown.
Defenses: Well developed anal musk glands, musking appears to be used primarily as a fear-defense mechanism and is associated with cautionary raised tail posture
Temperament: Highly aggressive if cornered, documented reports of wolverines chasing grizzly bears off their kills.
Diet: Mostly carnivorous
Lifestyle: Completely solitary unless raising pups or mating.

Weight: 26 pounds
Weapons: 34 small needle like teeth and claws which can be up to 40mm long.
Build: Badgers are heavily built, and have a broad head with small eyes. The legs are short, but the forelegs are well-developed.
Armor: Relies on thick shaggy coat to protect it from harm. Its muscular neck and thick, loose fur protect it when it is captured by a predator. It can run backwards as fast as forwards. It hisses, growls, squeals and snarls. It also releases an unpleasant musk that may drive a predator away.
Defenses: Very fast and accomplished diggers. They can dig a hole to safety in less then a minute. There are anecdotal accounts of badgers emerging from holes they have excavated through blacktopped pavement and two inch thick concrete.
Temperament: Badgers are not a very friendly species. They are easily agitated to aggression and will stand their ground when confronted to anything, including bears and wolves.
Diet: Badgers are carnivorous, but will occasionally feed on plants. Their main diet consists of burrowing rodents, which they hunt by sniffing them out with their powerful sense of smell, then rapidly dig them up with their long front claws. Badgers will also eat insect they come across while hunting. They have been known to raid hornet and wasp nest.
Lifestyle: Badgers are solitary animals, except when males and females meet up to mate, and when females are rearing their young. If one badger meets another, they will attack each other.


Here is how the fight would go down..
Both Wolverine and Badger catch wind of another animals kill and come running. Badger gets there first due to speed and chases off the predator, followed closely by the Wolverine. Both have their eye on the prize and both are too aggressive and stubborn to back off. The scent throwing begins, with the Wolverine puffing out his tail and spraying much like a skunk, this irritates the Badger causing him to do the same. Both animals are now smelly and extremely pissed off but no one is injured yet.

The Wolverine, after much posturing charges in and the fur starts flying. The Wolverine claws are ineffectual, causing minimal damage to badger due to its course wiry fur. The Badgers is able to use it's claws but only to impose superficial wounds on Wolverine due to its extremely thick winter fur. The Wolverines jaws and skull muscles are built to crush through ice and bone. After much scuffling and snarling and snapping of jaws the Wolverine manages to get ahold of the Badgers leg in its mouth, and its extremely powerful jaws snap the bones like a twig. The Wolverines diet of frozen meat has given it the edge and the Badger can not recover from a broken leg. While the Badger has long claws and quickness it lacks the overall jaw strength to pose a real threat and its teeth have trouble getting through to the Wolverine.

It would be a hideously nasty fight, but the ability to crush bone would give the Wolverine an edge in an otherwise almost perfectly matched fight.

The winner:

WOLVERINES !!!!

Sports Science Friday: Mouth Guards

Well kids, it's that time again!!! Lace 'em up, strap 'em on and let's go HIT somebody!!!!

But before we get started, it's important to remember one other form of protective equipment--beyond the house protection previously mentioned in Sports Science Friday back in December.

If you're gonna play smash-mouth football, then ya gotta protect those pearly whites.


From the experts at the Journal of the American Dental Association 2006 Dec;137(12):1712-20
Using mouthguards to reduce the incidence and severity of sports-related oral injuries.

The whole purpose of a mouthguard (usually constructed from some sort of thermoplastic copolymer) is to distribute and decrease any forces incurred to the teeth and other hard and soft tissue structures of the mouth by blunt force. A properly fitted mouth guard has been proven over and over again to protect players from significant injury from trauma. And, many of you may know, that if you break, chip, or otherwise avulse a tooth---you don't get much healing.

There are three types of mouth guards: The "ready made" or stock mouthguard, the mouth-formed or "boil and bite", and the custom made which is either vacuum formed or pressure laminated.

The stock mouthguard comes in a few standard sizes and requires you to keep your mouth closed so the thing will stay in. Many folks find this prohibitive as it is hard to breathe and talk with them in. Because they don't fit well, they don't protect well either. But they are cheap...

Next up is the mouth-formed or "boil and bite" variety. This is the most commonly used device and the one that I'm sure you've all purchased at a sporting goods store. Actually, more than once. Because as you all know, you have to get the temperature just right and then you have to bite it and form it just so, or the thing is wrecked....
But the best of the bunch is the custom made mouthguard usually made by a dental professional. It fits better, protects better, but is a whole lot more expensive.

But here's the thing. No matter what---Wear your mouthguard!!!

Hardest Hits in College Football

To Michigan's opponents, this season, I say: BRING IT!
GO BLUE!
BEAT THE BRONCOS!!!

Sports Science Friday: A bicycle built for "two"????

Le Tour de France 2009 kicks off on 4 July, scheduled to complete 26 July. This will be the 96th Le Tour, comprised of 21 stages and traversing 3500 kilometers. That's a LLLLLLOOOOONG time to put ones butt on a bike seat. And while it's really important to remember to wear black bicycle shorts and a truss, the bicycle seat is also a critical piece of equipment. Seriously. These guys have to worry about chaffing, hypoxia, erectile dysfunction, prostate irritation, and a whole host of other issues.
Sooooooo
For today's Sports Science Friday, I give you, bicycle seats, or how not to bust a nut.
I'm going to try and get back to the original intent of Sports Science Friday and present some data for you. From Drs. Liebovitch and Mor in the Department of Urology, Meir Medical Center, Affiliated to Sackler School of Medicine, Tel Aviv University.
"The Vicious Cycling: Bicycling Related Urogenital Disorders. European Urology, Volume 47, Issue 3, Pages 277-287"

These guys reviewed 62 articles and found the following staggering information about cyclists:

• 50-91% report genital numbness
• 13-24% report erectile dysfunction

Other reported problems include: priapism (Wayne's world, excellent!), penile thrombosis (er, clots in the penis?), infertility, blood in the urine, twisting of the spermatic cord (the thingy connecting the testes to the rest of you), prostatitis, and butt rash.
Obviously the longer or more frequently you ride, the higher your chance of these types of injuries. Extra points to anyone who can find a story about how the guys in Le Tour manage these issues! I can only imagine the 'enhancements' employed......

Another option is to adjust the type of bicycle seat you choose and how you use it. First, let me direct you to an amazing web page by a Mr. Jim Langley. Well done, sir, well done.

Now you and I call them bike seats, but apparently bike enthusiasts call them "saddles".

There a few general components of the saddle: the nose, the seat, and the seat post. The skinny front of the seat (aka the nose) is very useful because it allows you to move your legs up and down rapidly and increase your rpm's. But, this can lead to chaffing of the thighs since they get hot and sweaty and are exposed to a lot of friction.....that's where lube comes in, and it's particularly important to lube your chamois. Your chamois you say??? Yes, your chamois....check it out. Personally I like the ASSOS brand, because it is a ridiculously Beavis and Butthead kinda name, heh-heh.

The seat can also be modified. You'll notice in the picture above that some seats are split or have shock absorbers. Your position on the bike can also affect things. So mountain bikers are more at risk for urologic injury since you sit upright and have your buttocks on the seat for longer amounts of time, as compared to road bikers who are usually upright or leaning forward. Technically the best saddle is wide, heavily padded, with a flexible or absent nose. Who else had one of these beauties on the left as a kid???? The Schwinn Banana. oh yeah.....

One thing's for sure---you don't want to do this:

Now obviously ya can't talk Tour and bicycle seats without at least one mention of Lance Armstrong. When he was first diagnosed with testicular cancer a panic went up about bicycling and saddles specifically causing testicular cancer. Not true. While there may be an increased incidence of testicular cancer in bicyclists there isn't necessarily a causal link. So keep peddling.
For those interested in Lance's progress in Le Tour (or TdF for the cool kids) you can follow him on Twitter.....
The internets are an amazing thing. I found this picture by Annie Liebowitz for Vanity Fair. wow.

ok ok. here's my parting gift for the long weekend........

Sports Science Friday: Enhancements Part Duo

This week's edition of SSF continues the theme of enhancements. Somehow I started thinking about SI's Sport/Not a Sport column and synchronized swimming came to mind. Although the ladies from Arizona look pretty chilled out in the pool, this picture makes me think that synchronized swimming is soooooo not a sport.

Perhaps if it were enhanced in some way, it could qualify????
But what skills are required to succeed???
hmmmm.....treading water. pointing toes. floating.

floating. I've got it!!!! Enhanced flotation devices!!!!! THAT'S what this sport needs! Flotation enhancement!!!! But by what means???
Those of us girls out there remember this method from camp (and Judy Blume)



ok, sorry to say....it don't work!!

Luckily science has come up with implants which can go directly under the skin or under the pectoralis muscle to enhance the flotation capabilities of breasts. The key is to get saline implants, not the silicone ones because silicone has been linked to a number of medical problems. The silicone implant can break, leaking it's contents into the surrounding tissue. They no float no more.

It is also really important to find a well-trained plastic surgeon to perform the enhancement because you want them to be even, well-rounded, and of course supple (for non-pool activities).

Even better, from a competition standpoint the implants are NOT a banned substance! Enhance away ladies!!!! Make them as big as you can!!!!!!!!

Even though you won't be cheating, it is important to be able to size up the competition, so take this test (work alert) to see if you can tell the augmented from the non.

The new devices are sure to increase buoyancy making the synchronizing of the swimming thing a piece of cake!!! And maybe even your new favorite sport?????

Sports Science Friday: ENHANCEMENTS Part I

Well, the winter season has been slow and in all honesty my real world has kept me from feeling very creative...but I knew that if I didn't produce a SSF soon, there would be a mutiny. So.....I bring you the first of 3 entries on ENHANCEMENTS

Thanks to the expert from Mayo Clinic for the details.....
Carpenter, PC, Performance-enhancing drugs in sport. Endocrinol Metab Clin N Am 36 (2007) 481–495

There are a variety of drugs that are employed to enhance performance. Some might consider Red Bull a performance enhancer. Others may take a zillion multivitamins and protein shakes. Basically it's ANY type of substance that someone takes to gain a competitive advantage. aka ERGOGENIC AIDES (chocolate milk anyone???)

But---most often people really mean illegal substances or banned substances that people try to utilize (and hide) basically to cheat the system. Tony Mandarich just shared with Rick Telander (rhymes with teabagger?? sorry couldn't resist) and the world about his gerry-rigged rubber duckie attached to his dickie in order to store 'clean' urine during his playing days.....

"In the pet area I see this rubber doggy squeaker toy. I get that, then I go to another area and get a small hose, and in the medical area I get some flesh-colored tape. I'm like the Unabomber getting supplies. Back home I rip the squeakers out of the toy, tape the hose into one end and experiment by filling the thing with water. At the Rose Bowl I taped the toy to my back, ran the hose between my butt cheeks, taped the end to my penis, and covered the hose tip with bubble gum. I had gotten some clean urine from somebody else. The tester stood behind me, couldn't see anything, and when I removed the gum everything worked fine."

And there you have evidence of the value of a Michigan State education......but I digress.

Testosterone was the first widely used anabolic steroid, first synthesized in the 1930s and introduced by (0f course) the Russians into sport in the 40s and 50s. The 1964 Olympics was thick with 'em. (entendre intended). The steroids weren't regulated by the US until 1988 however when Congress finally passed The Anti-Drug Abuse Act which made the distribution or possession of anabolic steroids for non-medical purposes a federal offense. Thank you Nancy Reagan???? Especially because the truth of the matter is that now even adolescents ---both boys and girls--- are using steroids in high school.

The anabolic streroids are chemical derivatives of testosterone. They act by increasing protein synthesis within cells, specifically muscle cells. And because they are derivatives of testosterone, they also virilize--meaning they inhance male characteristics like hair growth, voice changes. But counter-intuitively all the excess hormone actually suppresses the body's natural production of testosterone so the testes shrink up and sperm production is impaired.

So, why do we really care? I mean cheating has been around for eons, right?? Many have said if ya ain't cheatin' ya ain't tryin'.
Well...here's the problem with anabolic steroids. Ready??

• Psychological dependence/abuse
• Testicular atrophy aka shrinkage
• Decreased sperm counts
• 'Roid rage
• Baldness
• Boobage (gynecomastia)
• Prostatic hypertrophy
• Acne
• Cholesterol alteration and risk for heart disease
• High blood pressure
• Dilation of the heart
• Hepatitis
• Blood clots
• Growth restriction in young kids

other than that, well, yeah--they're just fine (?????)

The other thing that athletes don't realize is that when you stop, you really atrophy and you don't rebound from all of the other damage that you've done to your heart or your testes/ovaries. Meaning you can make yourself infertile.

And here is a random weird co-inky-dink.
Anyone else notice that Madonna got REALLY really 'buff' all of a sudden. Kind of around the same time she and A-Rod were Kabbalahing together.
Things that make you go hmmmmm.

What about non-steroid enhancers? or non-banned substances???
If you go over to the GNC website you'll find all sorts of potions and powders that people completely swear by. None of which have been vetted by the FDA by the by. I'm convinced that GNC is the champion Snake Oil Sales group ever!! But--tell the truth. How many of you all buy them and use them???
And---are enhancements bad if you just want to look buff/cut? I mean if you aren't cheating why not try to look good or boost your workout success a bit???? Maybe it's just a matter of degree???
I'm not suggesting that Dreamy Tom uses anabolic steroids AT ALL. But he sure has heck did something to go from the combine to the commercial.
yummo.

So, everyone wants an edge, and 'supplements' seem to be the way to get it. To me it's the continuum from healthy nutrition to vitamin supplements to nutritional enhancements to medications/substances to flat out cheating. It seems inconsistent to feign huge outrage about professional athletes doping when almost every college sports program has strength and conditioning coaches.....Seriously, why is gatorade ok but GNC muscle building stuff isn't????????
(aside from the obvious fact that most of those nutritional supplements GNC sells get "excreted" in either liquid or solid form, making it a pretty silly 'investment'.......)
Is a lot of the enhancing really about vanity (consider weight lifters) rather than performance?

The vanity piece will be the topic of upcoming SSF's.....so stay tuned!!!

Sports Science Friday: Why balls have dimples

Back to our regularly scheduled programming......
with apologies to this, we will now determine why balls have dimples.

GOLF balls people. jeez. get your mind out of the gutter! Although this does get us back to the issue of drag......and also beer pong?

I'm talking aerodynamics here. Of a sphere.
The picture below is from aerospaceweb.org. I will try to translate their wonderful explanation.
Imagine if you will, a smooth round object (like a ping pong ball for instance) and the gust of air that it encounters as it tries to make it's way into a plastic cup at the other end of the table. Hey. Focus! Ok, so there are two types of flow: laminar flow and turbulent flow.
When a fluid (in this case air) flows in parallel layers without disruption then the flow is smooth or laminar. Here's a video.
When the fluid is disrupted in any way then turbulent flow around the object results.

The resistance that the ball experiences as it traverses the atmosphere to the cup (be it the pin at the 9th hole or the dixie cup at the end of the table) is not only dependent on: 1) the force exerted by the air on the front of the ball, 2) the friction of the air against the ball as the flow splits, as well as, 3) the pressure disruption/drag BEHIND the ball. By placing dimples on the ball, you disrupt the laminar flow around the ball thereby creating turbulent flow behind it. This actually decreases the drag on the ball (see the smaller area behind the ball as illustrated above). click the picture for a cool video example!

Turns out that you can actually calculate how much drag is created behind an object!!! It's called the Reynolds number (no units) that is a ratio between the inertia force and the viscous force affecting an object. Fun with fractions reminds us that if the Reynolds number is large than viscous forces around the ball are negligible (ie small denominator = big fraction). If the Reynolds number is small, then the viscosity of the fluid around the object has a more significant effect. Dimpling makes the Reynolds number DECREASE. (would this make a great exam question or what!!??)

So, we have learned that the dimpling makes the flow around the ball turbulent, thereby decreasing the drag. But--get this--changing the shape and configuration of the dimple also affects the Reynolds number. That's why the "best" golf ball has hexagonal or pentagonal dimples rather than circular ones. No matter the size or shape of the dimples on your balls, you will still need special skills to rescue you from this:
Now, I would be remiss if I didn't mention the OTHER force on a golf ball---LIFT.
But we actually already covered the importance of lift in a previous SSF. (You're welcome).

So, with that dear reader, I will leave it to you to field test the lift and drag on your balls......

Sports Science Friday: Substitute Teacher II

Since I know that T9 is soooooooooo busy with work (whatever...I know she was at the M/MSU women's game last night, because she was texting me updates). I will once again have to fill in for her for Sports Science Friday. A friend sent me this today, and I thought it was pretty funny. Since I wasn't ever really I "science" guy -- I will deliver a Sports Political Science Friday instead. I knew that LSA PoliSci degree would pay off sometime. If you happen to be from one of these countries, please do not take offense or declare "jihad on my ass", I am just the messenger.

If The Big 12 was the Middle East....

KANSAS = Saudi Arabia. Not altogether a bad place; has had historical success in oil and basketball, and continues to be a world leader in those areas. However, parts of the ruling family tends to thrive on its excess, much to its detriment; a certain prince's fondness for American culture (especially for its sweet baked goods) could very well lead to its downfall.

KANSAS STATE = Armenia. No one wants to be here, especially the Armenians. What's more, nobody really knows where it is. First came to prominence just a decade ago, and nobody can really remember it existing as an independent nation before that. Primary exports: Corn, junior college transfers.

NEBRASKA = Egypt. Was once a great power; its history, through the ages, is matched by few. Has languished in recent years, failing to recognize its new place in the world order as a follower, and not the leader it once was. Its people tend to be the friendliest to its neighbors, though still harboring a long simmering, yet contained, hatred for Israel.



COLORADO = United Arab Emirates. An incredibly refined populace -- probably because it's impossible to make it your home unless you're incredibly wealthy. Does its best to compete with its neighbors, but has resigned itself to being the playground of the region, instead of one of its traditional powers. Doesn't have a baseball team.

IOWA STATE = Afghanistan. There's really no reason that this nation should even exist, and if it weren't for previous colonial empires, it probably wouldn't. Easily overlooked over the last 300 years, its people are a ramshackle alliance of groups that don't belong anywhere else. Wishes to God, Allah, and whoever else that it would either cease to exist, or be swallowed up by Pakistan to the south, or the University of Iowa to the west.


MISSOURI = Turkey. Everyone is still trying to figure out how it got mixed up in this region, anyway. They're a member of NATO. Shouldn't they be in the Big Ten?


OKLAHOMA STATE = Syria. Nobody pays attention to them until they start mouthing off to the other nations around it. Will occasionally attack its neighbors, with varying success, with most of its successes coming in areas that others couldn't care less about, like wrestling.


TEXAS TECH = Iran. Really, REALLY wants to be noticed in the international community. Will go so far as to fake the development of nuclear weapons, or choose homicidal, maniacal, self-aggrandizing men as their president/basketball coach, just to get noticed. Incredibly eccentric as a nation. Has a deep-seated hatred of both Israel and Iraq--and a huge inferiority complex to go along with it. Very arid, dry climate featuring frequent windstorms.


BAYLOR = Lebanon. Everything they do is just a cluster, and no matter what they do, nothing ever seems to get better. Every once in awhile, it'll nip at the ankles of one of the larger nations, and piss those other nations off just enough to where they're smacked down and consequently can't achieve anything noteworthy for the next ten years.


OKLAHOMA = Iraq. Lies, cheats, and steals to get its way in the international community. If caught doing something wrong, or illegal, its excuse is that "everybody else has done it, we just get caught." No one wants to live here, but everybody that does wishes they could move away. Recently has undergone minor restructuring due to numerous ethics violations.



TEXAS = Israel. Pretty much everyone else in the region hates them. Can destroy lesser countries at will using incredibly advanced tactics. Not relegated to the stone-age lifestyle of many of its neighboring nations. Home of God's chosen people.


TEXAS A&M = Palestine. Doesn't actually exist as an entity to really be dealt with, but loves nothing more than to take pot-shots at Israel, just to tick them off. Economy based on farming, with an emphasis on sheep. Continuously complains that they're the real power in the region, and that their status should supersede that of Israel. Religious zealotry abounds; small, infrequent attacks on its neighbors are hailed as moral victories.

Sports Science Friday: The Zamboni Machine

The Inventor: Frank J. Zamboni, Jr. (our story courtesy of zamboni.com)
Mr. Zamboni, born in Utah at the turn of the century, ended up in Southern California in the 1920s where he and his brother started a refrigeration business working with the dairy industry. As part of this business they made block ice...but just like the horse drawn carriage, the utility of block ice soon dwindled. Being a smart business man in the 1940s meant morphing that block of ice into sheets of ice and they opened an ice rink (yeah. in Southern California) Well, you can imagine what the quality of said ice was and how often it would need grooming. Zamboni needed a quick way to resurface the ice....and well, the rest, is history. He developed a machine that would "a machine that would shave the ice, remove the shavings, wash and squeegee the ice, and hold snow in an elevated tank large enough to last for an entire resurfacing job. "

The Science
We all know how cool the Zamboni is--that huge thing up front and the magic squeegie dragging behind. The driver hugging the boards but looking behind at the same time to make sure that no spots are missed....Wouldn't it be great to drive one!!!

The thingy dragging behind is called the "conditioner"(A) and the first thing that happens is that a knife scrapes the slushy ice away. Next, a spinning auger device (one horizontal screw with another vertical/perpendicular screw) lifts the scrapings up off of the ice, then up and away into the front of the Zamboni. Really the slush is 'pushed' up the vertical screw (C) by the continuous motion and production of slush from the horizontal screw. (B) All that slush stuff gets pushed up to the front of the Zamboni (D) awaiting it's final resting place outside the rink in a pile.
Next warm water from the fresh-water tank (E) is sprayed onto the ice thru the conditioner to clean it. This dirty water is then squeegeed, vacuumed up, and filtered and returned to the tank. Finally, hot water is then poured onto the ice and spread by a towel (G) to form a new clean surface.

The Pattern
From the dochertyfamily: (THAAANK YOOOOU!!)

The Zamboni magic happens because the machine gently overlaps the path it has already cleaned. The secret is the series of concentric ovals starting in the lower left corner of the rink....and ending in the lower right.

Now the trick that I really can't explain is how things work with TWO Zambonis on the ice. While the NHL has been using 2 for a while as it cuts the cleaning time, I was shocked to see the guys at Yost using 2 Zambonis for a midget's game the other night! But then I realized that it would take longer to clean with one Zamboni than it would for the kids to play a period and it all made sense (particularly given the cost of ice time!!!!)

If you want to buy one for your backyard, be ready to pony up anywhere between 10,000 and 250,ooo green ones. If you don't have that kinda cash, you can always make yer own....