Apple #599: C:\ Drive and 404 Not Found

Now that the Olympics has ended (sigh), it's time for me to get caught up on a few requests.  I've got one that comes from a reader and one that comes from me.  Since they're both computer-related and brief, I'm combining them into one entry.

C:\ Drive


C:\ command prompt
(Image from DeviantArt)


Regular Daily Apple reader Jeremiah wants to know, why are computer hard drives labeled c:\?  Why not a:\ or q:\ or any other letter?

Well, I know why it's not called a:\. Those were floppy drives.  But why the hard drive isn't called any other letter of the alphabet, I don't know.

• The reason it's called c:\ turns out to have about as much thought behind it as, because floppies were called a:\.

• IBM came up with this naming convention.  Way back in the days of the first computers, there really wasn't a thing like a hard drive -- at least, not the way we know hard drives today.  Most of the information was supplied by some external source, like a floppy disk.

 

The 8-inch floppy disk. First introduced in 1971, with storage capacity of about 100K.

(Photo from Old Computers.net)

The 3 1/2 inch floppy disk, first introduced by Sony in 1980.

(Photo from Old Computers.net)

This is a Macintosh (circa mid-1980s) with a floppy drive visible in the front.

(Photo from Only HD Wallpapers)

• Since floppy disks were usually what you needed even to boot the computer, their drives were called a:\.

• As computers got more advanced, they began to require users to load one floppy disk, switch to another and load that, and sometimes switch back to the first.  So it became convenient to add a second floppy drive, called -- you guessed it -- b:\.

• Some people, when they tell this story, say that the b:\ drive was for a different type of external media, namely, tape drives.  Tape drives obviously had different dimensions and specifications than a floppies, so they needed a different drive altogether to handle those, and thus, those got called b:\. 

Various versions of magnetic storage tape (not cassette but computer), with a floppy at far right, all sitting on top of a tape drive.
(Photo from Wikipedia)

• I'm not sure which of the two versions is more reputable -- b:\ drive is second floppy or b:\ drive is tape drive -- so I'll leave it to you to decide which tale you prefer.

• Hard drives, which came along a little later, got the next available letter, c:\.

• People have wondered, now that there aren't floppy drives anymore, and very few people use tape drives -- or even mention b:\ drives -- why not bump the hard drive up to a:\?

• Answer: because every computer-related thing is standardized to look for the hard drive at c:\. Software, hardware, peripherals, you name it, when it wants to find the hard drive, it says, "C:\? Where are you?" If the hard drive were re-named anything else, c:\ would go unfound. It would wander, lost and lonely, through the world of computers, friendless and disconnected....

404 Not Found

This is the closest I could find to what I remember about how the 404 Not Found message used to look.  Ah, Netscape. Remember Netscape?  Good times.

(Image from AlphaSoftware)

• Speaking of things not found, I wanted to know why that web error message you used to get -- not so much anymore, but every once in a while it does pop up -- had that number 404 at the beginning.

• Once upon a time, long long ago in 1992, the World Wide Web Consortium (but mainly some guy named Tim Berners-Lee) came up with a list of codes, each of which stood for a different type of web browsing event. If some web page wasn't able to display anything helpful, it would at least display a handy 3-digit number that would tell you what was going on. The codes are specific enough so that, if there's some problem in communication, the code displayed would tell you where the communication broke down.

• The codes were based, by the way, on FTP status codes. Those go all the way back at least to 1985, if not longer.

• There are 5 categories of status codes. The first digit indicates the category.  The categories are as follows:

• 1xx = Informational. Request received, continuing process
• 2xx = Success. Action was received, understood, and accepted.
• 3xx = Redirection. Needs further action to process the request.
• 4xx = Client error. The request contains bad syntax or cannot be fulfilled.
• 5xx = Server error. The request is apparently valid, but the server failed to fulfill it.

• Since the 2xx's indicate success, you would hardly ever see a 2xx code.  The 4xx's mean that something about the request you made didn't work.

• The second & third digits work together as in, "01" "02" "03" or "10." Some of the categories only go up to "07" or "05" or even only as far as "01." The 4xx's -- the "it's your fault" codes -- go all the way up to "17." Of course. Always blame the user.

• What seems to be counter to "it's your fault" is that the 4xx's are also considered transient errors. Meaning, this is the information we're getting from the server at the moment. But if you try again a bit later, your request might work after all.

• Here are the codes for the 4xx's:
• 400 = bad request
• 401 = unauthorized
• 402 = payment required
• 403 = forbidden
• 404 = not found
• 405 = method not allowed
• 406 = not acceptable
• 407 = proxy authentication required
• 408 = request timed out
• 409 = conflict
• 410 = gone
• 411 = length required
• 412 = precondition failed
• 413 = request entity too large
• 414 = request URI too large
• 415 = unsupported media type
• 416 = requested range not satisfiable
• 417 = expectation failed.

• Some of those seem redundant, but other seem like they would be just as useful as 404, if not moreso. Some, like 401 payment required or 401 unauthorized, seem like they would still come in handy today. I might have seen 400 maybe once.  But I don't think I've seen any of the other ones ever.

Well, I'll be dipped. Somebody did get a 410 gone. This is from Germany, though, so maybe that explains it. German precision engineering and all that.
(Image from Schnurpsel, which word I did not make up, I promise.)

• But the point is, why, if there are all of those "it's your fault" codes, did we only ever really see 404?

Getting a little more current, another 404 Not Found display.
(Image from ZackTheTech)

• It's rumored that 404 was named after a room at CERN, where the original web servers were located. But that rumor is incorrect. There isn't even a room numbered 404 at CERN.

• The truth seems to be that 404 turned out to be a very handy catchall. It means that you've done something wrong, but it's not being very specific about what that problem is. Maybe you mistyped something, but it's not sure. It also can't say for sure whether the page or sever you tried to access is permanently gone or disabled. All it knows is it couldn't make the connection. 

• In fact, it's not really sure about anything, just that there's a problem. If you try again, though, it might work. Or it might not,

• That's a pretty handy error message:  "It's not working and we're not sure why! But try again and see what happens!"

This is what the 404 Not Found screen looks like these days.  You can see the 404 status code at the bottom of the window.
(Image from Evagoras Charalambous) 

• Actually, these status codes are still in use today. In fact, there are now extended codes, which add a decimal point and another digit after the 404 to give you more detail about why you got the 404. Not every site will use the extended codes, but some do.

• From the web developer side of things, if you can access the log files for a website, you'll see that one of the fields indicates the HTTP status code. This page parses the data you'll see in log files and points out where the status code appears.

• I think I need to employ 417 Expectation Failed on a more frequent basis.

• Hey, check this out! You can get 410 Gone T-shirts! Nerds, delight. Ooh, and they have a 417 Expectation Failed one too. I might just have to invest in one of those.

(T-shirt from Zazzle)

Sources
Computer Hope, Why is the hard drive the C: drive?
SuperUser, Why start at c drive in modern computing?
Locker Gnome, Why is the Hard Drive called "C" by default?
404lab, a brief history of 404
Hypertext Transfer Protocol 6.1.1 Status Code and Reason Phrase
GetNetGoing, Help for HTTP error 404: "Not Found"

Apple #598: Olympics Medley

As the Olympics wind down to a close, I thought I'd show you the answers I found to a host of little questions that I had about various bits & pieces from different athletic events.  It's a medley of Olympic facts!

Diving: What's up with those little towels that the divers carry around all the time?


Christina Loukas drops her shammy down from the diving board during the women's 3M springboard prelims.
(Photo by David Eulitt of the Kansas City Star)

• They're called shammies or sammies.  

• Like the chamois (pronounced shammy) towels for drying off your car, they used to be made of actual chamois, which was the skin of a particular goat that lives in Europe and Asia. Towels made of this material were super-absorbent, so they didn't need to be big.

• Now, however, these towels are made of synthetic poly-vinyl materials which are just as absorbent. So instead of calling them by the original French word, they're now called by the way the French word is pronounced: shammy (or shammies, plural).

• Some divers call them Sammies because of this: in 1977, Dr. Sammy Lee was coaching the US diving team at the Swedish cup. A Norwegian diver was using a shammy, and he gave it to Dr. Lee, who passed it on to a member of his team. The team started calling the coach Shammy instead of Sammy. The team member to whom he'd given the towel was none other than Greg Louganis. When Louganis started winning all sorts of medals for his diving, the kind of towel he was using became popular too. When a company in the states started making the towels, Dr. Lee stamped his name Sammy on them, so people called the towels Sammies.

The Sammy towel sells for between $12 and $20 each.
(Photo from Swimx.com)

• The reason this towel is so popular is because divers need their hands to be dry before they execute a dive. This is so, when they clamp their hands around their legs to do a tuck or a spin, their hands won't slip. This would not be a good time for your hands to slip.

• So the divers will bring their shammies / Sammies up onto the board with them, dry off, toss the towel down to the deck, and retrieve it after the dive.

• Since the shammy is pretty much the only thing a diver carries around during a competition, most divers have developed all sorts of rituals around their shammy. They towel off in a certain way, or tie it in a knot, or twirl it, even carry it around with them like a security blanket.

Great Britain's Tom Daley has a tie-dyed shammy.  Here, he's using it to cover his eyes between dives.
(Photo from UK Eurosport)

This leads to my next question, which is:

Diving: How come the divers go into those little pools after they dive?

Especially if they need their hands to be dry, why do they go in the water and get wet again before their next dive?

• Divers are athletes. Like all athletes, they need their muscles to stay warm and loose. If they got out of the diving pool and toweled off and just stood around waiting for their next dive, they'd get cold and tighten up.

• So they go into those little pools -- which are like hot tubs -- in between dives. The water in the little pools is kept at a higher temperature than the regular swimming pool so the divers will stay warm.

Divers waiting in the hot tub in between dives. Notice they all have their shammies with them.
(Photo from Business Insider)

Swimming: How do the swimmers shave down?  Do they shave or do they wax?

I was on my school's swim team as early as the third grade.  I was never fast, and I have enough 5th and 6th place ribbons to prove it, so I wasn't on the high school team.  But we young ones swam the same practices with the older girls, so that's how I learned about shaving down.



Hooray!  We're body-hair free!
(Ricky Berens, Ryan Lochte, Michael Phelps at Beijing 2008)
(Photo from Heavy)


Here's the deal with shaving for swimming.  Body hair increases drag and slows you down in the water.  Less body hair makes you faster. Research has been done that proves this, so shaving down has become a pretty standard practice in the sport since about the 1950s. What a lot of swimmers do -- this is true for both men and women -- is not shave for the majority of the season, until a key meet.  Then they'll shave pretty much everything that's not covered.

This is partly for the physical benefit of reducing drag by that 1%, but it also gives you the sensation of feeling slicker and quicker in the water.  Imagine shedding all that hair one day and then getting in the water -- whoo!  You feel slick as a seal.

The question I had as I watched the Olympic swimmers compete was, do they shave, which means having to shave several times over the course of the competition, or do they wax?
 


We're so well-shaven, it's kind of unbelievable!
(After Dana Vollmer, Rebecca Soni, Missy Franklin, and Allison Schmitt set a new world record in the 400M relay at London 2012)
(Photo from The Strata-Sphere)

• I couldn't find anything definitive that says such & such percentage of Olympic swimmers shave while 100 minus such & such wax.  But it looks like most swimmers do still shave, while a few here and there will wax.

• I did find this page from Michael Phelps' autobiography, describing the first time he ever shaved down.

• I did find a video of a couple Danish women swimmers waxing each other's armpits before the competition.  So those swimmers, at least, prefer to wax.

• Kerri Walsh-Jennings, who is not a swimmer but a beach volleyball gold medalist, says in preparation for her tournaments where she wears bikinis, she neither shaves nor waxes.  She says, "I hate getting waxed.  Waxing makes me want to punch someone in the face." So she gets her unwanted hair removed with lasers.

That fan is practically shrieking, "Those lasers did a great job!"
(Kerri Walsh-Jennings after her 2nd gold medal win at the Beijing Olympics in 2008)
(Photo from Pregnant Hollywood)

• Laser hair removal is the option that yields the longest-lasting results, but it's also the most expensive by far, and it can also give you scars or hyperpigmentation.  So you would want to make sure the person lasering the hair off of you is certified and has a lot of experience.

• But for most of us regular people, and even for most competitive swimmers, shaving is still the way to go. Here are some tips for shaving down:

• For regions that may be longer or more lush, start with an electric trimmer or razor first. Shorter hair is easier on ye olde razor blade, which you want to be sharp.

• Most swimmers shave their legs and arms. Men also shave the chest and back. Even if you don't have a visibly hairy chest or back, shaving down those little hairs can help.

• For areas that you can't reach, have someone shave there for you. This is why lots of swim teams have shaving parties the night before a meet.

At this team shave-down, a swimmer named Matt is getting waxed.

• What not to shave: some say that shaving the underside of the forearm isn't necessary.  This part of your arm pulls you through the water, and you could use the extra help pushing the water out of your way here.

• You also don't need to shave your head. Swim caps are sufficient to reduce drag. If you want to shave your head for some team spirit reason, go ahead. But you don't need to.

• Shaving your specials isn't necessary either.  Anything that's covered by the suit already has help in reducing friction in the water. Most women swimmers will keep their bikini line clean for visual purposes, but anything beyond that is your personal choice.

Track & Field: How come so many US runners are wearing those bright yellow shoes?


Looks like every runner but one in this group is wearing the neon yellow shoes.
(Photo from Natural Running Center)

• Ah, Nike is glad we've asked. In fact, that is exactly what they hoped we would do.

• Nike is not a sponsor of the 2012 Olympics, but they have given these particular shoes, with the color named Volt, to US track & field athletes to wear in competition. (They also gave the shoes to boxing and fencing athletes; 400 athletes total.)

• Nike intentionally made the shoes neon yellow because that color really catches the eye of anyone watching. They knew it would stand out especially well against the red track.

• They wanted these shoes to be so eye-catching that we would all ask what they are and then, because the athletes wearing them did so well, we would all be so overcome with the desire to own a pair for ourselves, we would run out an buy them in droves. At $100 to $200 a pair.

Nike Volt shoes, up close.
(Photo from Vehicle Media)

• Nike has done all this without actually sponsoring the Games.

• Other companies -- like Adidas -- pay hundreds of millions of dollars to be an official sponsor. But Nike has not forked over such cash, and they are not an official sponsor.  But because their shoes are so prevalent and visible, and because they've made a few commercials that mention London (along with a lot of other cities and without saying "London Olympics" or "London 2012") and they aired them during Olympics broadcasts, people think that Nike is a sponsor.

• There is a department called the Olympic Delivery Authority that tries very hard to make sure that non-sponsor companies don't benefit financially from an association with the Olympics that they didn't pay for.  

• When this group got wind of the Nike shoes situation, they considered going after Nike with a lawsuit. But they changed their minds, probably when this publicly-funded group realized what big pockets they would be going up against.

• There is also a rule which restricts athletes from appearing in ads during and shortly before the Olympic Games. But this rule doesn't say anything about what the athletes can or can't wear in terms of branded apparel. So although the athletes can't tweet about their shoes or post photos on facebook or Instagram, they can wear them. On TV. In front of millions of viewers.

The US women's gymnastics team compete barefoot. But at their medal ceremony, they were all wearing the Volt shoes. That's how pervasive these shoes are.
(Photo from Natural Running Center)

• After reading all this, I kept wondering, why would the athletes wear the shoes? These people are super-attuned to their sport, and shoes have got to be a crucial part of their equipment. Bad shoes or the wrong shoes introduced at the last minute could have devastating results. So why would they wear a pair of shoes simply because some Nike marketing person handed them over?

• Because, first of all, Nike sponsors a ton of athletes. The thing all these business magazines and newspapers are all geeked about is that Nike didn't pay to sponsor the Games.  They're all thrilled because they think Nike seems to be getting away with something. But Nike does sponsor a boatload of athletes. 

• It's therefore in the athletes' interest to wear the shoes because Nike has probably helped them out in a huge way, financially and equipment-wise, for a long time leading up to this moment.

• Still, my question persists. So wearing the shoes might be a way of thanking their sponsor. That's nice. But there must be something performance-wise that they like about the shoes.  So why did the athletes choose to wear these shoes over something else they might have trained with?

• The best I could discover is what Nike says about their own shoes. They say that, for the shoes that have spikes, the spike plate is especially lightweight which gives runners who wear them a slight edge over their competitors. Nike says their other types of shoes in this series which do not have spikes are also lightweight, and they are engineered for a precision fit to feel like a second skin.  Apparently, lots of athletes agree.

 
Nike Volt shoes for sprinters. This group is called Zoom.
(Photo from Nike, Inc.)


These Nike Volts are "flats" for the distance racers. And maybe preferred by the general public.
(Photo from Runblogger)

• By the way, Nike will be an official sponsor of the Games in Rio in 2016.

Oh, and one last thing. No, the gymnasts don't wear anything under their leotards. That goes for men and women.


Sources
Diving
Swimx, The Sammy Towel
NBC Olympics, 10 things you should know about diving
iSport, Why Divers Use a Shammy
Swimming
iSport, How to Shave Down for a Swim Meet
howstuffworks, Why do swimmers shave their bodies? Shaving Tips for Swimmers
Solo Swims, Shaving Down: The effects on swimming of removing body hair
Swimmer's Daily, Danish Darlings introduce Mie to their Wax On Wax Off ritual
Livestrong, What Do Swimmers Do to Remove Body Hair?
Daily Mail, "'Waxing makes me want to punch someone': Team USA beach volleyball stars on getting their bodies in shape for THAT skimpy kit", July 30, 2012
Well Being Tips, Split Seconds Count - Olympic Swimmers and Hair Removal
Track & Field
AdAge Global, Consumers Don't Really Know Who Sponsors the Olympics
Forbes, Ambush Marketing: An Olympic Competition. And Nike Goes for Gold, August 7, 2012
NBC News, The Bottom Line, Nike takes marketing gold with neon-yellow shoes, August 10, 2012
Metro News, Yellow volt shoes a hit at London Olympics, August 12, 2012
Nike, Inc. Nike Unveils Volt Collection for Track and Field

Apple #597: Pommel Horse

The voting on which entry I should do next was a dizzying deluge, but the winner is clear: pommel horse. One Daily Apple reader in particular said that the reason she wants to know more about it is to learn why our American gymnasts don't seem to be very good at it.

I'll start off with some basics, and then hopefully along the way I'll be able to uncover what makes it so challenging.  Whether or not I can say why our gymnasts have trouble with it, we'll see.



Krisztián Berki of Hungary won gold in the pommel horse at London 2012. Look at that insane extension of his legs.

(Photo from Kagura-girl)


What's a Pommel?

• First things first, let's define this word pommel.

• I had thought the pommel was the knob that sticks up from a horse's saddle. But it's not the knob (which is actually called the horn); it's the arch on which the horn rests.

 
This diagram of a Western saddle is pretty complex, but it shows where the pommel is. It's the arch that stands up from the saddle, and the horn stick sup from that.
(Diagram from Fine Saddles)

• The real purpose of the pommel is that it holds the saddle together.  But conveniently for the rider, you can also grab onto it if your horse is bucking.  The horn, which sits atop the pommel, makes the emergency grab even easier. 

• The other purpose of the pommel is to help you mount the horse in the first place.  After you put your foot in the stirrup, you reach across the back of the horse to grab the pommel on the far side of the saddle and use that as leverage to pull yourself up.

• The thing to note here is that when you're mounting the horse, after you've pulled yourself up on the stirrup, you have to swing the other leg over the back of the horse.  

• When you're dismounting, from a seated position, you lean forward on the pommel to push yourself up so you're standing in the stirrups, then swing your right leg back over the horse and, with one foot still in the stirrup, bring your legs together, then turn to remove your foot from the stirrup, and slide down to the ground.

This instructor takes every step of mounting and dismounting very slowly and deliberately, but if you're patient, you'll see the similarities with pommel horse gymnastics routines.

• Sound familiar?  That's because the gymnastic pommel horse event comes from the art of horse mounting. 

Pommel Horse Origins

• Long, long ago, going at least as far back to Alexander the Great's time, soldiers used to practice mounting a horse by using a wooden horse as a model. 

• In the 17th century, a drill instructor began teaching his students various horseback acrobatics as a way to improve their ability to mount horses under all sorts of challenging battle conditions.  Soon the cavalrymen were showing off about who was the best at these various equestrian acrobatics.

Pommel horse from 1795.  As far back as that, the legs allowed for adjustable height.
(Image from GymMedia) 


Pommel horse today.
(Photo from Smartly)

• The soldiers' routines mainly involved climbing onto or jumping over the horse.  While the false horse did have two pommels, they didn't really figure into the acrobatics much.

• But eventually, when the practice moved from the battlefield into the gymnasium, the gymnasts began to use the pommels as something to swing from, first with one leg, then the other.  By the 1880s or so, German gymnasts had innovated the two-legged swing, and that is where the real similarity with today's sport begins.

• To back up and clarify a bit, there was this whole movement in the 1800s in Germany, emphasizing the importance of exercise as part of any man's education (back then, it was only men who were going to school).  Gymnasiums sprang up at universities all across Germany, as men were trained to exercise their bodies as well as their minds. 

• During this time, a gymnastics instructor developed all sorts of equipment and exercises as part of the effort to exercise his pupils in new and more challenging ways.  This instructor,  Friedrich Ludwig Jahn, developed the equipment or the exercises that went with them for the parallel bars, the horizontal bar, the vault, and the pommel horse -- all of which are standard elements of men's gymnastics today. 

Friedrich Ludwig Jahn, the guy who invented the gymnastics pommel horse as we know it today, and probably the focus of lots of curse words from lots of gymnasts.
(Image from Pfannhauser)

What Makes the Pommel Horse so Difficult?

• The pommel horse requires tremendous upper body strength.  You're swinging your legs around, doing handstands, spinning about, and your legs aren't supporting you at all. The only thing holding you up are your hands and your arms, and you have to hang on tight while your legs are whipping around.

This is Louis Smith, who won silver for Great Britain at London 2012. Please notice the enormous muscles in his chest and arms.
(Photo from not sure)

• Other events in men's gymnastics really put a strain on upper body strength, most notoriously, the rings.  Those things are just punishing.  So how is the pommel horse different?

• The pommel horse also relies very heavily on momentum.  You have to get a lot of speed going to execute those spins properly, and in fact, you rely on the momentum to carry your legs more than you could do on your own. If you make a mistake, you lose momentum, and you therefore also lose the ability to perform the next skill, and the whole thing falls apart like a house of cards.

• How you do each element depends on your individual height and weight.  You have to keep your weight distributed evenly throughout each skill or you'll get thrown off.  What's more, the differences in each person's body make it difficult to teach someone else exactly how to do a skill. A taller, thinner gymnast will have to hold himself differently than a shorter, heavier gymnast, for example. These variations make trial and error crucial to learning the skills. 

• Combining the importance of upper body strength and momentum, how you position your hands is crucial. Placing them in even the slightly wrong spot can throw off your weight distribution and thus your momentum, and then everything can go wrong very fast.

This is Danell Leyva of the United States at London 2012, just prior to falling off the pommel horse. I suspect that his critical mistake happened before this shot was taken and here he's already on his way off. But I think I can guess how this photo shows that he's destined to hit the floor.  His weight is thrown well forward of his supporting left arm, his right arm is only brushing the side of the horse which can't give him much support, he is bent at the waist, and his legs aren't held tight together. All of these things would throw anybody's balance off-kilter.
(Photo from The Spokesman-Review)

• The individual skills -- to say nothing of stitching them together into a seamless routine -- are just plain freakin' hard to master. 

• One of the central skills is to spin in circles. You might think this would be like flinging your legs out or up to get them to go over a horse, but that's not how you do it.  You have to keep your legs clamped together and rotate your hips to make your legs swing around. (This seems pretty intuitive to me, like how I spin myself around in an inner tube in the water. But it's probably a lot harder when you're holding yourself up in the air rather than floating in water and supported by an inner tube.)

• They say the best way to learn how to do the circles is not even to involve the pommel horse at all for the first few weeks or months because you'll be too freaked out by the possibility of whacking your legs or your special parts against the pommels. So you learn on what's called a mushroom, a little round table-like thing with a padded top, and you spin around that. Then you progress to mushrooms that are higher up and progressively more like a pommel horse.

• A common mistake people make when learning to do the circles is they bend at the waist in mid-circle. This slows you down and eventually makes you stop. You have to keep your body straight the entire way around the circle. 

• There are all sorts of techniques to keep you from "piking the circle," including putting your feet in a bucket which is attached to a rope that holds the bucket hip-high and helps keep your body straight as you work your way around the mushroom.

This looks like a mild form of torture to me.




The subtitles in this video are kind of annoying ("let's c some circles b4 we start"), but it shows the difference between someone who can do circles adequately and someone who can do them really well.




Why Aren't American Gymnasts Very Good at the Pommel Horse?

• Here we enter the realm of gray area and speculation.  So let me give you some data first.

• US athletes have not medaled in the pommel horse since 1984 -- which was also the year of the Soviet boycott, so they might not have even won then if the Soviets had been playing.

• Countries with the most medals in pommel horse, going all the way back to 1896:

• USSR or Russia -- 13
• Switzerland -- 9 (only 1 after 1936)
• Finland -- 6
• USA -- 6 (3 from 1904)
• Germany -- 5
• China -- 3
• Romania -- 3
• Great Britain -- 3

• Though the Russians haven't won recently, they have traditionally owned to the pommel horse.

• Why this is, I can't say for sure.  Perhaps it's just one of those things about sports, that the people who are best at it tend to stick around and coach the kids in their homeland. Since the younger athletes learn from the best, they in turn become the best. 

• As for why the US isn't all that great in it, I'd guess there's a similar factor working the other way: that their coaching hasn't been as good as the Russians'. All of this is just my guess, though.

Here's Xiao Qin, who won gold in the pommel horse at Beijing in 2008. He breaks his line a bit at one point, but he keeps going. His body is very straight throughout, and he keeps his speed.  (This video is from Televisa, so there's English & Spanish commentary.)



This is Alexei Nemov of Russia from 1996 in Atlanta. He took the bronze. But for my money, his performance is better. Obviously huge upper body strength, but he goes faster and more smoothly, the straightness and flexibility of his legs on the flares is impressive, and he didn't have a break in his line the way Qin did.  Yeah, I've watched a few videos so now I'm an expert.

• I will leave the final thought to Katia Bachko who, writing for The New Yorker, said this:

Everyone who is Russian has a thing for gymnastics. It’s an innate affinity. . . . We are born loving vodka, cold winters, and pommel horses. 

Sources
OneLook.com, pommel
Certified Horsemanship Association, How to Mount a Horse Video
GymMedia, History of the Pommel Horse
Livestrong.com, What is the origin of gymnastics equipment?, June 14, 2011
About.com, Men's Pommel Horse Olympic Gymnastics Medalists
The Atlantic Wire, The Weird End to the Men's Gymnastics Team Final: A GIF Guide, July 31, 2012
Drills and Skills, Pommel Horse Drills and Skills
Made Man Manual, Pommel Horse Skills
American Gymnast, Pommel Horse Training Progressions, July 10, 2010
BBC Sport Photo Galleries, Gymnastics Photo Guide
Katia Bachko, Why I Wish the Russian Gymnasts Had Won, The New Yorker, August 1, 2012

Apple #596: Kinesio Tape

I know I asked you, dear readers, to choose between two topics for my next entry: the pommel horse or synchronized diving, or to propose a third option.

One faithful Daily Apple reader posed a third option with this question:

Why do the divers have these big red streaks on their backs and legs? One Chinese diver had two parallel streaks on her lower back, one had one thicker one, and another diver had one on her front thigh. What does this mean? What is it made out of? Why doesn't it wash off in the water?

Wu Minxia, synchronized diver from China, wearing the muscle tape on her lower back and on her ankle.
(Photo from NBC Olympics Mobile)


I happen to know the answer to this.  It's muscle tape.  Athletes have been using it in lots of sports for several years.  But I'm glad you asked because it is sort of a mysterious material, and I would like to know more about it, too.

• The first time I remember noticing it for sure was during the Beijing games when beach volleyball medalist Kerri Walsh wore it on her shoulder.

 
Kerri Walsh during the 2008 Beijing Olympics, wearing black muscle tape on her shoulder.
(Photo by Georgios Kefalas, from Monsters and Critics)

• She had had surgery on her shoulder the year before the games. The surgery attended to problems with her rotator cuff, took out a bone spur, and got rid of some debris and scar tissue from a previous surgery. 

• Though her shoulder had healed by the time she got to Beijing, she was wearing the muscle tape to bolster it.

• I was struck by how it seemed flexible enough to conform to her muscles and the shape of her shoulder, allowing more specificity of placement and giving her more range of motion than a wrapped bandage would, and it never came off even though she was doing all sorts of diving into the sand and various other exertions, not to mention a lot of sweating.

• The brand name for it is Kinesio Tape. It was developed by a Japanese chiropractor named Dr. Kenzo Kase. 

Dr. Kenzo Kase, inventor of Kinesio tape.
(Photo from Kinesio UK)

• (Actually, there is another brand of this tape out there, called KT Tape.  But most people are talking about the Kinesio brand.)

• The tape, according to Kinesio UK, is flexible enough to stretch 30% to 40% longer than its resting length, it allows the skin to breathe, but it will stay on for 3-5 days at a stretch. (a little pun there for you)

• It's made of cotton, which is porous enough to allow moisture to escape through it, which means it will stay on even when it gets wet.  

• What makes it stick is a special heat-activated adhesive. When you first put it on, you have to rub it briskly to get the adhesive working, and then it will stick. 

• According to the company that makes Kinesio, the tape supposedly allows more blood flow to reach sore muscles by pulling the skin slightly away from the muscle. Its effects are to reduce swelling, pain, and muscle fatigue.

• Kinesio says there's a special way it must be applied, and they train and certify people in how to do that.  They say that there are now some 4,000+ certified Kinesio Taping (they put a little R in a circle after this) practitioners in the UK alone.

 
Kerri Walsh's tape was black, and for a long time, that was the only color of it that I saw. But now you can also get it in beige, blue, and red, as shown here. One roll sells for £7.95 (~$12.35), and a box of 6 rolls goes for £41.50 (~$64.40).
(Photo from Kinesio UK)



 
They also sell it in a different variety, called "fan cut." I'm guessing this is so you can spread out the ends to cover a lot of surface area more easily. A pack of 50 goes for £46.50 (~$72).
(Photo from Kinesio UK)

Ah, yes. Here is the fan cut option in use.
(Photo from North Coast Medical)

• As far as whether or not it actually works, opinions are mixed. There hasn't been a lot of medical research done on the tape, but what has been conducted has found that there is a short-term benefit in some circumstances, like increased r ange of motion, or a reduction in pain. But long-term, the studies haven't seen results any better than a placebo.

• It should be said that, even though this tape has existed for 30 years, there hasn't been a ton of research that's been able to cover the long-term.  

• It should also be said that the placebo effect can be a powerful thing.  In other words, if you believe that something will help you, it just might do so.

• Here are just a few other athletes who have used the Kinesio tape:

• Supposedly, some Japanese athletes wore it in the 1988 Seoul Olympics, but you couldn't see it under their clothes.

• Lance Armstrong and his team wore it.  Here's what Armstrong says about it in his (and his ghost writer's) book Every Second Counts:

The guy who put us all back together was our chiropractor, Jeff Spencer … Jeff is part doctor, part guru, part medicine man. He had all kinds of strange gizmos and rituals and cures, a remedy for every condition. . . . But Jeff had something that was better than any laser, wrap, or electric massager. He had The Tape. It was a special hot-pink athletic tape that came from Japan and seemed to have special powers. George got a problem with his lower back. Jeff turned him around and started putting hot-pink tape on it. George thought, “How can that help?” But the next day the pain had disappeared – it was gone. We swore by Jeff’s pink tape. He would tape the hell out of anything. You had a tweaky knee? He taped it. A guy would start to get tendinitis and he’d say, “Don’t worry. No problem. We’ll tape it.”

Leryn Franco, javelin thrower from Paraguay, wearing the blue Kinesio tape at the Athens Olympics in 2004.
(Photo from City Centre Chiropractic)

• David Beckham (soccer/football)
• Lots of other famous soccer players including Mario Balotelli
• Tiger Woods (golf)
• Rafael Nadal (tennis)
• Novak Djokovic (tennis
• Justine Henin (tennis)
• Jared Sullinger (college basketball)
• Edgerrin James (professional football)
• Paulo Villar (track) 
  
• Nikola Janovic (water polo)
• Alex Mumbru (basketball)
• Sara Goller (beach volleyball)
• Loads more athletes at the London 2012 Olympics

David Beckham sporting the pink Kinesio tape
(Photo from Merchant Circle) 



Serena Williams wearing it on her plaguey knees.
(Photo from Skirts N Sports)
 


Brigitte Foster-Hylton (2155) from Jamaica, in 100M hurdles at the 2008 Beijing Olympics, wearing the Kinesio tape.
(Photo from Skirts N Sports)



One veterinarian in the UK has even used it on horses.
(Photo from Manual Lymphatic Drainage)


The voting for my next entry has been a bit slim.  So far, the pommel horse is in the lead.  If you'd like to vote on what you'd like to read for my next entry, do so here.

Sources
Kerri Walsh says she'll be ready for Beijing, ESPN Olympic Sports, May 31, 2008
Kate Kelland, Reuters, Scientists skeptical as athletes get all taped up, Calgary Herald, August 2, 2012
Carly Weeks, The latest craze at the Olympics: body tape. But does it do anything? The Globe and Mail, August 2, 2012 
Chris Woolston, "The Healthy Skeptic: The sticky issue of kinesiology tapes," The Los Angeles Times, April 4, 2011
Fort Collins Gonstead Chiropractic
Dallas Medical & Chiropractic Clinic, Kinesio taping in Dallas
Kinesio UK
theratape.com, Kinesio Tape
IAAF Athletes Biographies, Brigitte Foster-Hylton
Men's Basketball: OSU Insider, The Columbus Dispatch, March 9, 2011

Your votes, please

I'm contemplating another Olympics-related Daily Apple entry in the near future.  Since my entry on water polo turned out to be so popular, I thought I'd get your input.

Which would you rather read about, 1 or 2:

1. Pommel horse in gymnastics -- what a weird thing, first of all, so where did it come from and why is a gymnastics thing and not an equestrian event? Second of all, it's plain amazing how fast the gymnasts get going on that thing, so how do they do that?

2. Synchronized diving -- how in the world do you learn this? How do you get your dive to be the same height as your partner's, your spins in the air going at the same rate, your untucking from the spin happening at the same time, your angle into the water the same, etc., etc.

Or is there a third item which has piqued your interest?  Here's a tip: the more specific your query, the better.  For example, asking me about swimming will probably get you a mish-mash of general information.  But if you say you want to know how to swim the butterfly stroke, then you might get something you're more satisfied with.

Let me know in the Comments.  I'm looking forward to hearing from you!

Apple #595: Water Polo

So I'm watching water polo on the Olympics, and I keep thinking, man, that looks hard.  I can't imagine treading water, fighting off the other player, and flinging the ball to the net, then having to swim as fast as possible to the other end of the pool.

On top of all that, I've heard that water polo is actually a rough sport, that there's a lot of scrapping and injuries.  It looks pretty benign, with all that water and the bathing suits and the funny caps, so it's kind of hard to believe it's all that rough-and-tumble.  The announcers aren't saying much about the behind-the-scenes--or under-the-water--truth about the sport.  So it's time for the Apple Lady to find out.


Water polo.  With all that splashing and waving of arms and swimming around, is it really that violent a sport?
(Photo from Wikipedia) 


HOW PEOPLE DESCRIBE IT

• One of the ways of knowing the nature of a thing is by how people describe it.  Here are some of the ways people describe water polo: 

• "A unique combination of swimming, throwing, and martial arts." 

• "The only contact sport played in the water"

• "An aquatic form of rugby." My brother played rugby for a while.  His face after a rugby match was usually pretty colorful with bruises and scratches and scrapes. If water polo really is like rugby, then it must be pretty high-contact.

NATURE OF PLAY

• But they wear those funny-looking caps. The caps are funny-looking, but there are reasons for that.  They tie under the chin so they won't come off when a player goes underwater, or is dunked, or is pushed or shoved.

• The reason you don't want the cap to come off is because it includes ear protectors. The ear protectors aren't to keep water from trickling into and clogging your delicate ears, but rather to shield your ears from getting bashed by an opponent's elbow, or from getting slapped by an opponent and your ear drum bursting as a result. 

   
There's also this.
(Photo from Water Polo blog)

• But all they're doing most of the time is treading water and waving their arms around.

• OK, first, the treading water part. To stay afloat while you're playing, you have to do what looks like treading water.  But the motion is different and harder than that. The especially effective method of treading water is called the "eggbeater kick."  You lift one leg at a bent position, as if you're sitting in a chair, while you kick out the other leg sideways and rotate it in a circle.  Then you switch legs and do the same thing.

The eggbeater kick, which water polo players use to stay afloat while they're playing.
(Photo from coachesinfo.com)

• Since kicking out your leg is a motion essential to the sport, it's easy to kick or be kicked accidentally.  And since it's hard for the refs to see from above water what's going on below the surface, getting kicked happens not so accidentally, and often, and without penalty. Usually, if an opponent kicks you, it's to try to keep you at a distance so the opponent can catch the ball or score or keep from being blocked. 

 
Here's a shot of some of what goes on underwater during a water polo match.  You can see people in the midst of their eggbeater kicks, but it also looks like the guy in the foreground may have just gotten shoved underwater by his opponent.
(Photo from SM Texas)

• As for the waving of the arms, that's part of defending, or reaching out to catch the ball.  As it turns out, lots of penalties happen during the defending process.  More on that in a second, but first:

• If you still think this is wimpy, you try raising yourself up out of the water high enough to throw a ball over someone's head, and faster than they can reach out to stop it -- all while not being able to stand on anything.

Look how high out of the water this guy is.  He's not standing on anything, he's just doing his special eggbeater kick to propel himself up higher out of the water.

(Photo from NorCal Water Polo)

There are tons of great photos out there of water polo players in action, showing how strong they are.  I can't show you any of them because they're all owned by Getty or Corbis.  So you'll either have to click the link to see for yourself, or just trust me when I say, these are some impressive athletes. 

PENALTIES

• A good way to assess how violent or physical-contacty a sport is is by what behavior has been banned.  This suggests that, even though such & such is not allowed, it does happen, and they've had to make a special rule outlawing that behavior.

• So I'll talk about the types of fouls that happen in water polo, from least serious to most serious. This is leaving out penalties like violating the amount of distance you're supposed to keep from the goal, or what you're not allowed to do when you're out of the pool, etc.  I'm only going to mention the physical types of fouls.

• In addition to kicking, opponents can get away with lots of infractions which are technically not allowed, but which the refs tend not to see because they happen underwater.  

• Wrist-holding: an opponent may grab your wrist and hold it in order to keep you from going after the ball or from raising your arm to defend against you. As long as your wrist is underwater, they can usually get away with it until you break their grip

• Grab-and-go: say you're on defense, in front of an offensive player. The offensive player reaches across to grab your arm and, using you like a stationary object, pulls herself forward ahead of you.

• Suit-grabbing: players don't grab opponents' bathing suits to disrobe and embarrass them, though that may happen. The men grab each other's suits at the waist to keep a defender low in the water and unable to block, or to keep an offensive player from getting up in the water to make a shot.  Female players may do the same thing, or they may also grab another player's shoulder straps, but since it's easier to get your shoulders out of the water, it's easier to attract the ref's attention and get a penalty called. (Mutual suit-grabbing here)

• Since suit-grabbing is pretty common, water polo players wear bathing suits that are as small and snug as possible.  Women water polo players are required to wear one-piece suits.

US Men's Water Polo team, 1996. I bet if it were safer to do so, and allowed, they would play without their bathing suits.  OK, yes, this is some eye candy for some of you Daily Apple readers out there.  But I posted this for another reason, which is to say, judging from how ripped these guys are, you probably have to be in this kind of super-great shape to play this sport. So I take this to be further evidence that this is a very physically demanding sport.
(Photo from The Hostages)

• There are, of course, many physical-contact things you're not allowed to do, and which will get a penalty called against you if you did them.  Since these things are outlawed in the rule book, I'm assuming that they do happen.

• Swimming across an opponent's legs.Your opponent is leaning forward for the ball, almost lying flat in the water, and you swim across her legs so that she can't swim as fast. Presumably you could get kicked, but she'll slow down, and you get to cut a corner essentially, and cut her off.

• Swimming on the opponent's shoulders. Yes, that's right, I said "on." As far as I can tell, this means essentially, swimming over an opponent, or pressing down on his shoulders to make him sink as you're swimming.

• Any other form of impeding, meaning you're somehow physically restraining the other person or holding them back or down in the water.  If the impeding looks violent or intentional, you can get kicked out of the game (more on that in a bit). 

• Striking the ball with a clenched fist. This puts too much force into a strike, but it also makes it likely that you would punch somebody by mistake. So you have to smack the ball with an open palm, which means you might slap somebody by mistake, but that's OK.

 
This is Lyuba Tschougounova, who played in junior college in 2009.  Looks like she's fending off two opponents at once, one who is actively trying to block her, and the other at the ready.
(Photo from Concordia Eagles)

• There are a whole series of infractions which are all classified as "acts of brutality." I am not exaggerating.  If a player is found to be committing an act of brutality, the payer is s kicked out (excluded) for the rest of the game, and a player from the opposing team gets a free shot at the goal (penalty throw).

• An act of brutality is defined as playing "in a violent manner, including kicking, striking or attempting to kick or strike with malicious intent against an opponent or an official."  Yes, against an official.

• Here are acts of brutality in water polo:

• Intentionally splashing an opponent in the face

• Holding (grabbing onto), sinking (pushing down into the water), or pulling back (grabbing onto and pulling away) an opponent who is not holding the ball.  Any of these things are allowed, apparently, if an opponent does have the ball.

 
The hold, sink, or pull back rule. This rule seems to be quite a big gray area, judging from the rule book's efforts to define what is happening in each diagram.  I'm guessing that it's like holding in football, that you're not supposed to do it, but that it happens all the time.
(Image from FINA Water Polo Rules)

This looks like this might qualify as a hold.  Once again, I can't show it to you here.  Thanks, Getty!

• Kicking or striking an opponent intentionally

• Using the elbow to strike backwards to hit an opponent behind you

• Head butting backwards to do the same

 
Striking with the elbow backwards is classified as a "brutality" and can get you kicked out of the game.
(Image from FINA Water Polo Rules)

• The key here, I suspect, is that the refs first have to see that you've committed the infraction, and then they have to interpret your actions as violent and intentional.  A player may think another player's actions are violent and intentional, but until the ref agrees, you may be stuck trying to fight the guy off.

 I wouldn't call this intentional, but it does look like this altercation could have turned into something fairly serious.


INJURIES

• Another way to find out how rough the spot is would be by finding out what kinds of injuries are common to water polo players. 

• As in any sport, there are lots of overuse or repetitive motion injuries. In water polo, those happen especially to the shoulder or elbow from throwing, or to the lower back from rotating while throwing, and to the groin and knee, from doing the "eggbeater kick."  And because it's a water sport, water polo players can also get inflammation in the ear canal, a.k.a. swimmer's ear.

• Most of the injuries in water polo fall in this overuse category, and most of the injuries are to the shoulder.

 
This is Lauren Wenger. She was named the June Athlete of the Month in 2009 by the US Olympic Committee.  Look at her enormous muscles in her shoulder.  That speaks to how strong water polo players' shoulders get from having to whip the ball as hard and fast as they can.
(Photo from Women Sport Report)

• But what about injuries sustained as a result of contact with other players?  What are those like?

• Contusions, or bruises, are very common, especially to the face.

• Lacerations, or cuts, are common too. You can get cut when the ball hits you in the face, or by a player's fingernails or toenails. 

• There are lots of eye injuries, including cuts to the face around the eye or cheekbone, black eyes, bleeding into the eye, scratched corneas, etc.

• Some players even sustain "blow-outs" or complete fractures of the bone around the eye.

• Sprains & fractures. Most often, these happen to fingers, which get hyperextended or bent or bashed when a speeding ball hits the hand at a strange or unexpected angle.  But sometimes the sprain or fracture happens because of contact with an opponent.

• Concussions or head injuries. These aren't that common, but they do happen, usually happen as a result of getting elbowed in the head or head-butted.

• Spine injuries. These can be a repetitive motion injury, from turning your head to breathe during freestyle swimming.  But some players have sustained cervical spine injuries due to blows to the shoulder area from another player.

• Fatal intracranial bleeding. In other words, a head injury that has resulted in internal bleeding on the brain, from which someone died.  I don't know any details about how this happened, only that it did happen to a water polo player.

 
Ervin Zador got punched in the eye during the "Blood in the Water" match between Hungary and USSR in the 1956 Olympics.
(Photo from Wikipedia)

• Recently, a sixteen year-old boy in Southern California who had just made the water polo team died during practice.  He said he was thirsty, got out of pool to get a drink of water, got back in the pool, and later, he was found unconscious at the bottom of the pool.  As of this writing, no cause of death had been officially determined.

All right.  I'm convinced.  Water polo is a demanding, physical, high-contact sport.

And to put some of the fun back into it, here you go:

Sauce for the goose....
(Photo from magaz!nes.com)

[Edit: Here we go. This video shows the underwater truth pretty succinctly.]


Sources
FINA Water Polo Rules

Miljenko Franić, Alan Ivković, and Ratko Rudić, Injuries in Water Polo, Journal of Croatian Medicine, June 2007

iSport, Underwater Tactics for Water Polo
Stop Sports Injuries, Water Polo
Jeno Kiss, Department of Orthopedics and Trauma, St. John's Hospital, Budapest, Sport related injuries in water polo
Palm Desert water polo player's death stuns family, friends, Los Angeles Times, June 18, 2012

Apple #594: Wildfire containment

This is another question that came up while I was away on vacation.  When those wildfires were burning in Colorado and elsewhere, news reports kept saying things like, "The fire is 30% contained," or "The fire is estimated to be 45% contained."  In one news story I heard on the radio, the reporter asked the fire chief how he calculated containment.  He said something about the amount of acreage involved, but he said it so quickly, I didn't catch it.

So I wanted to find out, how do they calculate what percentage of a wildfire is contained?


Wildfire taking out trees as it moves across the ground.
(Photo from Chez-Audelle)



On July 4, 2012, several wildfires were burning across the state of Montana. The percent containment figures make for a nice, neat graphic, don't they?
(Map from the Billings Gazette)


Percent Containment

• It turns out, there isn't any fancy calculation involved in arriving at percent containment.  It's an estimate.  Here's how it works.

• A wildfire encompasses a certain amount of area.  Imagine the area as a filled-in ellipse.  Most wildfires aren't like that; they'll often have portions bulging out in one direction or other, but for the ease of description, picture an ellipse.  The outer edge of the ellipse is the fireline.

• When firefighters try to put out the wildfire, their first goal is to stop it from spreading.  They may put up some kind of temporary barrier around the fireline, or they may dig trenches, or they may spread some type of retardant, or they may remove trees or easily burnable stuff from the projected path of the fire, etc.  All these techniques are methods of containment.

• When the fire chief gets interviewed and is asked some question like, "How close are you to getting this fire under control?" the fire chief tells the reporter what percent of the ellipse has some kind of containment barrier around the fireline.

• That's all there is to it.  There's nothing absolute about it.  It's an estimate based on the chief's understanding of the size of the fire at the time, and how much of a barrier they've put down so far.

Today, most wildfire containment methods use retardant dropped onto areas just beyond the fireline, as shown in this photo of the Waldo Canyon Fire, June 23, 2012

(Photo from The Colorado Springs Gazette)

Actual Containment: My Take

• Based on what I've read, it sounds to me like this % containment number is a number they tell the media to make them happy.  It's a number to give to the reporters (and to us the public) so we can feel like we have a solid and easy-to-grasp concept to cling to.  But as far as I can tell, firefighters do not themselves think in such terms.

• To them, containment = 100% contained.  The question for them is, how do we get from this fire burning out of control to 100% contained, and put out?

I find this to be a pretty fascinating map.  This is a map of the High Park Fire in Colorado as of June 21, 2012. The red area represents where the fire was burning on that date. The red outline is the "uncontrolled fire edge." The black outline is the "completed line," meaning where they have put some sort of fire control measure in please.  The map is very detailed, even including gray-shaded areas where an older fire once burned.  But nowhere does it say anything about containment--presumably because, according to firefighter parlance, containment had not yet been reached. To see a larger version of the map, go to Summit County Citizens Voice.
(Map from Summit County Citizens Voice)

• To answer this question, firefighters run all sorts of calculations--very complicated ones involving calculus and all sorts of higher math because there are so many variables involved in a wildfire.

• Here are some of the features about a wildfire that firefighters have to take into account:

• Fire intensity -- the rate of heat released by a fire. That's both radiant and convectional heat.

• Rate of spread -- the distance the fire moves horizontally over time. Usually this is calculated at the head of the fire.

• Fire type -- is it burning at surface or ground level, or is it burning in the crowns of trees

• Type of fuel -- usually when it's a wildfire, it's mostly wood and leaves that's involved, but maybe there are other materials in the area, especially if there are houses or industrial buildings.  Even if the fuel is nearly all wood, there are other factors to consider such as how wet is the wood, is it densely or loosely arranged, how big or small is it (fine fuels like sawdust ignite much more rapidly), how dense is the material (a rotten log will ignite more quickly than a sound log), and so on.

• Fuel load -- weight of fuel/unit area, often expressed as tons/acre

• Fuel chemical composition -- if there are chemicals identified in your type of fuel, what kinds of chemicals are they?  Of course if accelerants are involved, everything burns faster & hotter. But even if the fuel is primarily wood, high concentrations of resins or oils in the wood can increase flammability and heat output. On the other hand, if the wood has a high mineral content, particularly phosphorus, that will reduce or even retard flammability.

• Weather -- we hear the most about this one.  All sorts of factors with the weather come into play, including how fast is the wind blowing and is it blowing the fire toward unburned fuel areas. Of course whether or not it's going to rain is a huge factor, but air temperature and humidity will also affect the fire.

 


Obviously the intensity of the wildfire above is far greater than the one below.
(Photo, top from Treehugger. Photo, bottom from US Fish & Wildlife Service, sourced from Wildlife Risk Explorer)

•  As I said, those are only some of the variables the firefighters will take into account.  Some of those variables are easier to estimate than others.

• Then they take all that data and plug them into those very complicated equations to try to find the answers to questions like these:

• What kind of material would be the most effective at stopping the fire? 
• How much of that material will we need to create barriers around the entire fire?
• How fast will we need to build those barriers?
• How long will it take to reach 100% containment, given such & such barriers?

• Put in a very theoretical sense, firefighters are trying to solve the fire (equation) for containment (x).

• (If you're interested in what some of those complicated equations are, check out this paper from 1980. It gives instructions for how to run some of these equations on a pocket calculator. To run them yourself, you would need to know the data for at least 8 variables. I'm sure there are more sophisticated methods of running these calculations today, but this gives you an early, behind-the-scenes glance anyway.) 

Firefighters working on a wildfire in Australia
(Photo from Chez-Audelle)

• Of course, regardless of all this data, a wildfire is still wild.  Even though firefighters do their very best to find out everything they can about a particular fire and how it's behaving, and try to predict where it might go next and how fast it might get there, a wildfire can still be unpredictable.

• That's not something we like to hear, especially if homes are at risk of being burned and people's lives may be at risk.  So we get a very estimatey-but-it-sounds-official percent containment number in our news stories.

Related entries: Fire, Fire Departments

Sources
Forest Encyclopedia Network. All sorts of great information here. Especially good pages include Fire Intensity, Fireline Intensity, Rate of Spread, 
National Wildfire Coordinating Group, Contained; Containment; Control Line; Controlled
Frank A. Albini and Carolyn H. Chase, Fire Containment Equations for Pocket Calculators, USDA Forest Service INT-26B, January 1980
LAist, What Do Fire Officials Mean When They Say 'Containment'? 2008
Rebane's Ruminations, Wildfire Containment Percentage - Say What??!! August 18, 2009