How Do You Steer a Bobsled?

 Quinn Rooney, Getty Images
Quinn Rooney, Getty Images

Now that the Olympics are well underway, you might have developed a few questions about the games' equipment. For example: How does one steer a bobsled? Let's take a crack at answering this pressing query.

How do you steer a bobsled?

Bobsled teams careen down an icy, curving track at up to 90 miles per hour, so steering is no small concern. Drivers steer their sleds just like you steered your childhood sleds—by manipulating a pair of ropes connected to the sled's steel runners. The driver also gets help from the rest of the crew members, who shift their weight to aid with the steering.

Why do speed skaters wear glasses?

speed-skating

Speed skaters can fly around the ice at upwards of 40 mph, so those sunglasses-type specs they wear aren't merely ornamental. At such high speeds, it's not very pleasant to have wind blowing in your eyes; it's particularly nightmarish if the breeze is drying out your contact lenses. On top of that, there's all sorts of ice and debris flying around on a speed skating track that could send you on a fast trip to the ophthalmologist.

Some skaters also say the glasses help them see the track. American skater Ryan Bedford recently told the Saginaw News that his tinted shades help him focus on the track and filter out distracting lights and camera flashes from the crowd.

What kind of heat are the biathletes packing?

Getty Images

As you might guess, there are fairly strict rules governing what sort of rifles biathletes carry on the course. They are equipped with guns chambered for .22 LR ammunition. The gun must weigh at least 3.5 kilograms without its magazines and ammunition, and the rifle has to have a bolt action or a straight-pull bolt rather than firing automatically or semi-automatically.

Is a curling stone really made of stone?

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You bet it is, and it's not just any old stone, either. Curling enthusiasts swear by a very specific type of granite called ailsite that is only found on the Scottish island of Ailsa Craig. Ailsite supposedly absorbs less water than other types of stone, so they last longer than their competitors.

Ailsa Craig is now a wildlife sanctuary, so no new ailsite has been quarried since 2002. As a result, curling stones are incredibly expensive. Kays of Scotland, which has made the stones for every Olympics in which curling has been an official event, gets prices upwards of $1,500 per stone.

What about the brooms?

The earliest curling brooms were actual brooms made of wood with straw heads. Modern brooms, though, are a bit more technologically advanced. The handles are usually made of carbon fiber, and the heads can be made of synthetic materials or natural hair from horses or hogs. Synthetic materials tend to be more common now because they pull all of the debris off of the ice and don't drop the occasional stray bristle like a natural hair broom might.

What are the ski jumpers wearing?

Getty Images

It may look like a ski jumper can pull on any old form-fitting bodysuit and hit the mountain, but things are a bit more complicated than that. Their suits have to be made of a spongy material and can't be thicker than five millimeters. Additionally, the suits must allow a certain amount of air to pass through them; jumpers wearing suits without sufficient air permeability are disqualified. (This rule keeps jumpers from wearing suits that could unfairly act as airfoils.) These rules are seriously enforced, too; Norwegian skier Sigurd Petterson found himself DQed at the 2006 Torino Games due to improper air permeability.

Those aren't the only concerns, though. In 2010, judges disqualified Italian jumper Roberto Dellasega because his suit was too baggy.

What's up with the short track speed skaters' gloves?

Gloves
Cameron Spencer/Getty Images

If you watch a bit of short track speed skating, the need for gloves quickly becomes apparent. When the skaters go to make passes or careen around a turn, they need the gloves to keep from cutting their hands due to incidental contact with other skaters' blades.

There's more to the gloves than just safety, though. Since the skaters' hands often touch the ice during turns, they need hard fingertip coverings that won't add friction and slow them down. The tips can be made of any material as long as it's hard and smooth, but you've got to give American skater Apolo Ohno some style points for the gold-tipped left glove he broke out in 2010.

What Do Those Recycling Symbols and Codes Mean?

iStock.com/ChrisSteer
iStock.com/ChrisSteer

Earth Day is here again, serving as an annual reminder of the need to reduce, reuse, and recycle our way to a better planet.

When it comes to the last part of that familiar three-”R” mantra, most people know enough to separate certain items from the rest of their garbage, but much of our modern recycling routine remains a mystery. From the recycling symbol itself to what those numbers on plastic containers actually mean, there's a lot you can learn from your trash before it becomes someone else's treasure.

An International Symbol With An Earthy Origin

The universal recycling symbol—three folded arrows that form a triangle, with the head of one arrow pointing to the tail of the next—was created in 1970 by University of Southern California student Gary Anderson as part of a contest tied to the very first Earth Day. Each arrow of the design represents one of the steps in the recycling process: collecting the recyclable goods after use, breaking them down and reforming them, and then packaging new products in the containers.

Originally designed as an inverted triangle, the symbol was later rotated to the pyramid-like orientation commonly used now.

The Number Game

The American Society of Plastics Industry first began using numbers inside the recycling symbols on plastic containers in 1988 as a way to assist with sorting them. The "Resin Identification Code" uses seven numbers to identify the type of synthetic material used to manufacture the container, with the higher numbers representing less commonly used plastics.

Here's a primer on each of the codes:

1. Polyethylene Terephthalate (PETE/PET)
Usually accompanied by the letters "PETE" or "PET," this resin is generally used for soda bottles and other containers for edible and non-edible goods. When it's not being used to manufacture containers, you might recognize it by another name: polyester. (Yes, it's the stuff that insulates your jackets.) It's also one of the most widely accepted forms of plastic in curbside recycling programs, though the amount of useable material available for new products after breaking down this plastic is relatively small.

2. High Density Polyethylene (HDPE)
The second most widely used resin for plastic bottles, HDPE is a stiff, strong material with a high resistance to chemicals, which has made it the go-to plastic for food items like milk and juice, as well as household cleaners and trash bags. It's also easy to break down in the recycling process and easy to reform, making it one of the most efficient consumer plastics. Most curbside recycling programs have no problem with accepting products made from this plastic.

3. Polyvinyl Chloride (PVC)
First discovered in the 19th century, PVC is commonly used in building materials today—especially pipes and plumbing material—due to its strength and chemical resistance (although it's occasionally used for some household products). It has a nasty habit of releasing highly carcinogenic toxins into the atmosphere when it's burned, so recycling is a significantly less appealing option for PVC disposal, and it's usually not accepted by curbside recycling programs.

4. Low Density Polyethylene (LDPE)
This plastic is becoming more common today, especially for manufacturing squeeze bottles and grocery bags. Plastics made from LDPE are usually very strong, and they're regularly used as sealants because of this quality. While they weren't included in curbside recycling programs at first, plastics made from LDPE are now becoming more commonly accepted.

5. Polypropylene (PP)
Regarded as one of the “safest” plastics produced today, PP is generally used for squeezable bottles, bottle caps, and straws. Along with LDPE, it's also used for food-storage containers that can be reused over time. It has an extremely high melting point, so it's one of the best consumer plastics for items that will be exposed to heat. Like LDPE, it's becoming more common for curbside recycling programs to accept items made from this plastic.

6. Polystyrene (PS)
More commonly known as styrofoam, this type of plastic is not only notoriously difficult to recycle, but it's also been shown to leach dangerous toxins over time into anything packaged in it—and even greater amounts of toxins when it's burned. This is the resin usually found in disposable serving trays, egg cartons, and cups, and it's rarely accept by curbside recycling programs due to the danger it poses and the difficulty of recycling it. Basically, this is the worst of the bunch.

7. Everything Else
There are countless other plastics, but very few of them are easily recycled in curbside programs, making this category the catch-all for everything that could conceivably be broken down and reformed, but might be better off reused or reformed in some way that doesn't require a chemical process. This category encompasses everything from bulletproof material to those large water jugs on office coolers, and is rarely included in curbside recycling programs.

Safety In Numbers

For anyone wondering which plastics are safe to reuse in their current form, it's widely accepted that HDPE (2), LDPE (4), and PE (5) can be reused multiple times for edible items, as they're generally resistant to chemicals, haven't been shown to degrade, and don't leach dangerous substances into their contents.

This story first ran in 2013.

What Do the Terms on Energy-Saving Light Bulbs Mean?

Scott Olson, Getty Images
Scott Olson, Getty Images

There's a reason your parents used to scold you for not turning off a light when you left a room. According to the U.S. Department of Energy, an average American household uses up to 5 percent of their total energy expenditure on lighting. Living rooms get flooded with light. Dining rooms and dens are full of lighting accents. Motion lights, hallway lights, bathroom vanity lights, lamps—we like our lives to be nice and bright.

Fortunately, energy-saving lighting sources have largely replaced the conventional incandescent bulbs that once used up a substantial amount of power. Those bulbs heated up a coil, or filament, of tungsten wire that gave off light. Roughly 90 percent of the energy they passed on was in the form of heat, which siphoned off energy and kept utility bills inflated. Today's bulbs brighten without the waste. That's the good news. The bad? The varieties of bulbs can be confusing. If you've ever been lost in the fixtures section of the hardware store, here's a quick primer on what these terms mean.

Halogen Incandescent:

These are incandescent light bulbs that contain a halogen gas-filled capsule around the filament to help increase energy efficiency. While cheaper to operate than a conventional incandescent bulb—they use 25 to 30 percent less energy—they don't produce as much of a cost savings as other options. On the plus side, they reach full brightness immediately. Other choices may take time to warm up.

Compact Florescent Lamp (CFL):

When you see a coiled light bulb, it’s likely to be a CFL, which is simply a downsized version of the tubular florescent lighting seen in commercial spaces. Instead of an electric current traveling through a filament like in an incandescent bulb, the current goes through a tube containing argon and mercury vapor. The resulting ultraviolet light activates phosphor inside the tube, which emits light. It uses one-third of the energy of a halogen incandescent. The downside? They can take a little time to warm up, especially if used outdoors. They also contain mercury, a potential health hazard if the bulb breaks. (See the "mercury" entry below.)

Light Emitting Diode (LED):

This type of bulb uses a semiconductor to convert electricity into light. In addition to being energy-efficient, they usually last eight to 25 times longer than halogen incandescent bulbs and four to eight times longer than CFLs—perhaps as long as 18 to 46 years. You'll probably pay more up front, but the expense is offset by their durability. Most LEDs are compatible with dimming switches, too. Most CFLs aren't, so if that's important to you, you'll want to stick with LED.

Energy Star:

A bulb with an Energy Star label was evaluated by a third party to make sure its energy-saving claims are accurate, and they'll typically have a longer warranty than bulbs without the endorsement.

But what about the "nutritional label" style information box that appears on light bulb packaging? Let's take a closer look.

An example of a label that appears on energy-efficient light bulb packaging is pictured
Federal Trade Commission

Brightness:

You have probably inferred that brightness refers to the light output given off by a bulb. This is measured in lumens and rounded off to the nearest five. (A bulb will never be 822 lumens. It's 820.) The higher the number, the brighter the bulb. Since you're probably used to shopping by wattage, consider that a bulb with 800 lumens is roughly the equivalent of a 60-watt incandescent. A 1100 lumen bulb will resemble a 75-watt bulb.

Estimated Energy Cost:

This is a rough estimate of much it will cost an average household to operate the bulb. What's average? The wattage of the bulb is calculated with three hours of daily operation at a cost of 11 cents per kilowatt. Your actual cost will go up or down whether you use it more or less or pay your energy supplier a different amount.

Life:

This is how long the bulb is expected to last based on the same usage estimated for the energy cost and rounded to the nearest tenth of a year.

Light Appearance:

This refers to the color temperature of the bulb measured in Kelvin, a temperature scale measuring light color. The range is from 2600 K (yellow and warm) to 6600 K (blue and cool). Bright white is about 3500 K. You should probably avoid anything above 3000 K for any interior room.

Energy Used:

This is how much energy the bulb will require and is measured in watts. The lower the wattage, the cheaper it costs to operate. This is where the energy savings materializes, as a 10-watt LED bulb may give off as much light as an old 60-watt incandescent.

Color Rendering Index (CRI):

It's not on all bulb packaging, but if you see it, it refers to how accurate colors will appear under the bulb's light on a scale of 0 to 100. Halogen incandescent bulbs score high. CFLs and LEDs aren't quite as accurate, though they may still get the job done. Try to get a high CRI if you'll be using the bulbs in a bathroom, as skin tone can appear off with lower CRI numbers.

Mercury:

You might see some CFL bulb packaging with a mercury disclosure. This isn't an issue if the bulb remains intact, but if it breaks, it might release potentially hazardous mercury vapor and the introduce the very small possibility of mercury poisoning. Avoid using CFL bulbs in kids' rooms if there's potential for knocking over a lamp or light. Broken bulbs that contain mercury should be cleaned up by following Environmental Protection Agency guidelines—picked up with tape, not vacuumed—and disposed of properly. Old bulbs should be recycled.

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