Before we take a look at how some of this gear actually works, I'm going to introduce the topic of Work to help make all this make way more sense for everyone.
Work, in science, is applying a force over a distance. The more force used, the more work gets done. The more distance the force is applied over, the more work gets done. It's a straightforward concept and will help to explain a lot of what Olympians use to accomplish their sports.
Now, onwards! To the gear!
The Science of Ice Skates
Ice skates allow for controlled movements over slick surfaces...at least, as long as the wearer knows how to balance properly.
In the Olympics, several sporting events rely on ice skates, such as hockey, figure skating, and speed skating. Let's focus in on the difference of the blades that you would see between each of these types of skates.
In hockey, the blade is simple and short, to allow for fast turns and ease of braking (and, I'd like to think, to avoid violence-prone hockey players from having daggers sticking out of the fronts of their boots). The blade typically runs only the length of the boot itself. Any longer, and it would require more force to change direction when skating. The longer the blade, the more friction it has when moved sideways, so turning quickly on a long blade takes a lot more effort than turning on a short one.
Because of this, hockey players do give up a certain amount of speed they could gain from having longer blades. Figure skaters actually have a bit longer of blades than hockey players, which they need to help accelerate them into jumps. The longer blade allows for the skater to use their force over a bigger distance. Remember Work? Great. More distance means more work! A longer skate allows for greater amounts of work to be done, without having to apply greater amounts of force. In the case of skating, this work is often related to speed and acceleration.
In speed skating, this concept is taken to an extreme. A speed skate's blade is typically 50% longer than a figure skate's. Some even detach at the back to lengthen the stride of the skater by giving them a long lever arm to continue to apply force over after their foot has already moved on to the next step. This is used in long track speed skating.
|A detachable style speed skate.|
It's all a tradeoff between speed and maneuverability. Figure skaters attempt to find the sweet spot between the two, while hockey players favor quick turns and speed skaters favor straight-on speed.
The Science of Skis and Snowboards
The idea of Work and using force over long distances also applies to skiing and snowboarding, as you might have already deduced. However, the way in which is applies might be more surprising.
Skis and snowboards are designed to "float" a person on top of snow. Just like being in a boat, a person needs a certain amount of surface area on their floating device so that they don't sink. Skis and snowboards have enough surface area to keep their riders upright, but not much more than that, so as to reduce excess weight or bulkiness in the equipment.
Cross country skis divide up this surface area differently than downhill (or "alpine") skis. Cross country skis are much more narrow throughout their length, to reduce drag as the skier moves through the snow. This require them to have a longer length than alpine skis, just by the nature of needing to keep up the right amount of surface area.
Alpine skis, in contrast, tend to be shorter and to have a waisted shape (where they narrow only towards the middle section). Much like with skates, the shorter length of an alpine ski allows skiers to turn more quickly. Additionally, the specialized shape creates differences in weight along the length of the ski--which allows for the ski to bend and be more flexible during a turn.
To increase the Work in skiing, the extra distance is achieved not by the length of the ski alone, but also by the pole. The pole acts as a lever to extend the arm, and give an extra set of limbs to push a skier along the ground.
But in snowboarding, there is no pole. As far as getting help from gear goes, snowboarders must solely rely on the length and shape of their board to change their speeds.
|Image Credit: Alain Carpentier|
Now that we've covered all the things athletes stand on, let's take a look the things they don't stand on. Let's look at the sleds!
The Science of Bobsled, Luge, and Skeleton
When athletes go hurdling down ice slides at over eighty miles per hour, they need something to help them out. That something might take the form of a bobsled (the biggest of the sled-types, and the one that offers the most protection) or the luge or skeleton style sled (both essentially a smaller bobsled stripped of its protective siding).
All three sled types are designed to be as aerodynamic and lightweight as possible. Extra weight actually helps speed things along when a sled is hurdling down a slide, but it's important to be able to control where that weight is. Having that weight with the athletes is better than having it with the sled, since the athletes can shift themselves accordingly to center their masses, and thereby steer.
|Old-style bobsled, complete with steering rings!|
Rather than tugging on strings just directly attached to the front runners, athletes double their work by doubling their distance--using strings that are looped around a pulley system. Using a pulley takes less muscle force by the athlete, so they can be more precise and less strained during steering. Which, when you're going close to 90 mph, can only be a good thing!
Alas, with the Olympics coming to a close in a few short days, this post concludes my 2014 Science of the Olympics blog series. Perhaps we shall meet again in 2016, when we're back to the Summer Games! Until then...!