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How Do You Steer a Bobsled?

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Now that the Olympics are well underway, you might have developed a few questions about the games' equipment. How does one steer a bobsled? What sort of gear do you need to jump into the competitive world of curling? Let's take a crack at answering some of your most pressing queries.

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?

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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?

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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?

skate-gloveIf 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.

This post originally appeared in 2010.

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iStock // Ekaterina Minaeva
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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Amazon
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This Week's Best Amazon Deals You Can Still Get
May 28, 2017
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Amazon

As a recurring feature, we share some amazing Amazon deals we’ve turned up. These items were the ones that were the most popular with our readers this week, and they’re still available.

Mental Floss has affiliate relationships with certain retailers (including Amazon) and may receive a small percentage of any sale. But we only get commission on items you buy and don’t return, so we’re only happy if you’re happy. Good luck deal hunting! 

GADGETS, TOYS, AND MEDIA

EasyAcc 6000mAh MFi Slim Compact Power Bank, Built-in MFi Cable for Apple Lightning Devices, iPhones, iPads, iPods, and USB Port for Universal USB devices for $18.39 (list price $49.99)

WizGear Universal Air Vent Magnetic Car Mount Holder with Fast Swift-Snap Technology for Smartphones and Mini Tablets, Black for $6.99 (list price $18.99)

HQDmall Fidget Cube Anxiety Stress Relief And Relieves Stress Attention Focus for Children and Adults Anxiety Attention Toy, Black for $7.99 (list price $29.99)

SENSO Bluetooth Headphones, Best Wireless Sports Earphones w/ Mic IPX7 Waterproof HD Stereo Sweatproof Earbuds for Gym Running Workout 8 Hour Battery Noise Cancelling Headsets for $36.97 (list price $169.99)

Fitbit Flex 2, Black (US Version) for $59.95 (list price $99.95)

Anker PowerCore Fusion 5000 2-in-1 Portable Charger and Wall Charger, AC Plug with 5000mAh Capacity, PowerIQ Technology, For iPhone, iPad, Android, Samsung Galaxy and More for $21.99 (list price $50.99)

Anker 60W 6-Port USB Wall Charger, PowerPort 6 for iPhone 7 / 6s / Plus, iPad Pro / Air 2 / mini, Galaxy S7 / S6 / Edge / Plus, Note 5 / 4, LG, Nexus, HTC and More for $25.99 (list price $79.99)

AELEC S350 Bluetooth Headphones Wireless In-Ear Sports Earbuds Sweatproof Earphones Noise Cancelling Headsets with Mic for Running Jogging for $21.99 (list price $129.99)

SoundPEATS Bluetooth Headset V4.1 Wireless Earbud Mini In-ear Bluetooth Earpiece Car Headset Hand-free calling with Mic for iPhone/Android/Windows 10 Cellphones, Tablets and Computers (Black) for $15.29 (list price $39.99)

TaoTronics Bluetooth Receiver / Car Kit, Portable Wireless Audio Adapter 3.5 mm Stereo Output (Bluetooth 4.0, A2DP, Built-in Microphone) for Home Audio Music Streaming Sound System for $13.49 (list price $15.99)

Seagate Backup Plus 4TB Portable External Hard Drive USB 3.0, Silver (STDR4000900) for $109.99 (list price $129.99)

Funko POP TV: Golden Girls Dorothy Action Figure for $9.00 (list price $12.00)

LEGO STAR WARS TIE Striker 75154 for $45.88 (list price $69.99)

Ace Armor Shield (6 PACK) Screen Protector for the Fitbit Alta HR with free lifetime Replacement warranty for $7.85 (list price $11.99)

VicTsing Shower Speaker, Wireless Waterproof Speaker with 5W Driver, Suction Cup, Buit-in Mic, Hands-Free Speakerphone-Gray for $20.99 (list price $24.99)

Seagate Expansion 2TB Portable External Hard Drive USB 3.0 (STEA2000400) for $69.99 (list price $73.99)

Anker Bluetooth Folio Keyboard Case for iPad Air 2 - Smart Case with Auto Sleep / Wake, Comfortable Keys and 6-Month Battery Life Between Charges (Not compatible with iPad 9.7 inch/iPad Air) for $35.99 (list price $69.99)

Anker 2.4G Wireless Vertical Ergonomic Optical Mouse, 800 / 1200 /1600DPI, 5 Buttons - Black for $19.99 (list price $49.99)

FRiEQ Universal Waterproof Case for Outdoor Activities - Waterproof bag for Apple iPhone 7, 7 Plus, 6S, 6S Plus, 6, 6 Plus, 5S; Galaxy S6, S4; HTC One X, Galaxy Note 3, Note 2; LG G2 - IPX8 Certified to 100 Feet (Black) for $6.99 (list price $19.99)

Fritesla 20000mah Power Bank 4USB Portable Charger for Smartphones (Green) for $24.99 (list price $100.00)

KITCHEN

Moscow Mule Hammered Copper 18 Ounce Drinking Mug, Set of 4 for $21.48 (list price $40.00)

OXO Good Grips Nylon Potato Masher for Non-Stick Cookware for $6.99 (list price $9.59)

Imarku Pro Kitchen 8 inch Chef's Knife High Carbon Stainless Steel Sharp Knives Ergonomic Equipment for $29.99 (list price $99.99)

Lodge L9OG3 Cast Iron Round Griddle, Pre-Seasoned, 10.5-inch for $16.19 (list price $24.00)

Cuisinart CSBP-100 3-in-1 Stuffed Burger Press for $11.47 (list price $14.99)

Wilton Nonstick 6-Cavity Donut Pan for $8.15 (list price $9.99)

Cuisinart Set of 3 Fine Mesh Stainless Steel Strainers, CTG-00-3MS for $11.21 (list price $22.00)

BLACK+DECKER GD2011B Family Sized Electric Griddle, 20 x 11-Inch, Black for $16.57 (list price $39.99)

Circulon Sunrise Whistling Teakettles, 1.5-Quart, Black for $19.99 (list price $40.00)

Rachael Ray Cucina Hard Porcelain Enamel Nonstick Covered Round Casserole, 4.5-Quart, Agave Blue for $27.69 (list price $100.00)

VonShef 7- Egg Electric Cooker Stainless Steel with Poacher & Steamer Attachment for $19.94 (list price $34.99)

The Original GORILLA GRIP (TM) Set of 3 Non-Slip Reversible Cutting Boards, BPA Free, FDA Approved Materials (Set of 3 Boards: Green) for $19.99 (list price $39.99)

Presto 04820 PopLite Hot Air Popper for $17.55 (list price $29.99)

Contigo AUTOSEAL Transit Stainless Steel Travel Mug, 16 oz, Polar White with Grayed Jade Lid Accent for $15.55 (list price $24.99)

AUTOSPOUT Straw Ashland, 24oz, Monaco for $8.49 (list price $12.99)

HOME

URPOWER 2nd Version Essential Oil Diffuser, 100ml Aroma Essential Oil Cool Mist Humidifier with Adjustable Mist Mode,Waterless Auto Shut-off and 7 Color LED Lights Changing for Home Office Baby for $15.95 (list price $39.99)

Radha Beauty Aromatherapy Top 6 Essential Oils 100% Pure & Therapeutic grade - Basic Sampler Gift Set & Premium Kit - 6/10 Ml (Lavender, Tea Tree, Eucalyptus, Lemongrass, Orange, Peppermint) for $14.95 (list price $79.99)

Sherpa Throw Blanket Lt Grey 50x60 Reversible Fuzzy Microfiber All Season Blanket for Bed or Couch by Bedsure for $23.99 (list price $59.99)

Hoover Vacuum Cleaner WindTunnel 3 High Performance Pet Bagless Corded Upright Vacuum UH72630PC for $139.51 (list price $189.99)

LANGRIA Shredded Memory Foam Pillow Firm for Optimal Orthopedic Support, Removable Washable Bamboo Cover Hypoallergenic Anti-Bacterial CertiPUR-US Certification,Queen Size for $12.99 (list price $59.99)

Downy Unstopables In-Wash Scent Booster Beads - FRESH, 26.5 oz. for $10.97 (list price $15.99)

Aszaro Cedar Balls, Cedar Cubes & Cedar Sachets 40 pc Combo Pack | 20 Natural Cedar Wood Balls, 20 Blocks & 5 Bonus Sachets | Ward Off Moths, Mildew And Mustiness For Easy Garment Care for $17.97 (list price $25.99)

Garment Steamer, Holan Portable Handheld Clothes Steamer, Fast Heat-up and 200ml Capacity Fabric Steamer with Two Brushes Perfect for Home and Travel for $17.99 (list price $39.90)

Monkey Hook Picture Hanger Home and Office Pack, 30 pc set for $11.25 (list price $19.75)

Queen Size SafeRest Premium Hypoallergenic Waterproof Mattress Protector - Vinyl Free for $29.95 (list price $95.98)

LUCID Premium Hypoallergenic 100% Waterproof Mattress Protector - 15 Year Warranty - Vinyl Free - Queen for $19.99 (list price $40.00)

HANSLIN Desk Top Swivel Alarm Clock for $23.75 (list price $29.99)

WBM Himalayan Glow 1002 Hand Carved Natural Salt Lamp with Genuine Neem Wood Base/Bulb and Dimmer Control, Crystal, Amber, 8 - 9-Inch, 8 - 11 lb for $30.98 (list price $39.95)

 

HEALTH AND BEAUTY

BS-MALL Makeup Brushes Premium Makeup Brush Set Synthetic Kabuki Cosmetics Foundation Blending Blush Eyeliner Face Powder Brush Makeup Brush Kit (10pcs, Golden Black) for $9.99 (list price $39.99)

Nerdwax Stop Slipping Glasses as Seen on Shark Tank for $10.99 (list price $14.99)

Crest 3D White Luxe Whitestrip Teeth Whitening Kit, Glamorous White, 14 Treatments - Packaging May Vary for $34.69 (list price $44.99)

Gillette Fusion Manual Men’s Razor Blade Refills, 12 Count, Mens Razors / Blades for $33.97 (list price $47.99)

Neutrogena Ultra Sheer Dry-Touch Sunscreen, Broad Spectrum Spf 45, 3 Fl. Oz., Pack Of 2 for $11.24 (list price $14.99)

Neutrogena Ultra Sheer Body Mist Sunscreen, Broad Spectrum Spf 30, 5 Oz. for $7.47 (list price $10.99)

Thinksport Kid's Safe Sunscreen SPF 50+, 3oz for $10.87 (list price $11.99)

Colgate MaxFresh Wisp Disposable Travel Toothbrush, Peppermint - 24 Count for $3.41 (list price $7.99)

100% Pure Australian Tea Tree Essential Oil with 45% Terpinen-4-ol, 1 fl. oz. A Known Solution to Help in Fighting Acne, Toenail Fungus, Dandruff, Yeast Infections, Cold Sores.. for $10.95 (list price $65.00)

American Crew Forming Cream, 3 Ounce for $7.95 (list price $9.67)

Aquasentials Mesh Pouf Bath Sponge (8 Pack) for $8.49 (list price $12.99)

Neutrogena Oil-Free Acne Wash Redness Soothing Facial Cleanser With Salicylic Acid, 6 Fl. Oz. for $6.50 (list price $10.69)

Edge Shave Gel for Men Sensitive Skin - 7 Ounce (Pack of 6) for $17.82 (list price $26.99)

NIVEA Men Platinum Protect 3-in-1 Body Wash 16.9 Fluid Ounce for $3.11 (list price $4.99)

Gillette Fusion ProGlide Manual Men's Razor Blade Refills, 4 Count, Mens Razors / Blades for $13.22 (list price $18.03)

Radha Beauty Rosehip Oil 4 oz - 100% Pure Cold Pressed Certified Organic for $13.95 (list price $49.99)

OFFICE, SCHOOL, AND CRAFTS

SwissGear 1900 Scansmart TSA Laptop Backpack - Black for $54.99 (list price $130.00)

Cardinal by TOPS Products OneStep Printable Table of Contents and Index Dividers, 52-Tab, Numbered, Multi-Color (60990) for $7.15 (list price $11.51)

Chartpak Self-Adhesive Vinyl Capital Letters, 6 Inches High, Black, 38 per Pack (01184) for $16.65 (list price $21.99)

Fineliner Color Pen Set,0.38mm Colored Fine Line Point,Assorted Colors,10-Count for $6.58 (list price $9.99)

uni-ball 207 Impact Gel Pens, Bold Point (1.0mm), Blue, 12 Count for $20.00 (list price $26.46)

Elmer's Liquid School Glue, Washable, 1 Gallon, 1 Count for $14.08 (list price $20.49)

Westcott Jumbo Circles Template (T-826) for $4.31 (list price $7.00)

Amzdeal Magnifier Eye Glasseses Eye Loupe For Reading Drawing Making handicrafts Repairing for $11.89 (list price $39.99)

OUTDOORS, GARDEN, AND SPORTS

Coleman 12 oz. Enamel Mug for $3.49 (list price $8.98)

Igloo 5 Gallon Seat Top Beverage Jug with spigot for $22.99 (list price $39.99)

Mountainsmith Pinnacle Single Trekking Poles, Evergreen for $12.91 (list price $19.95)

Polar Bottle Insulated Water Bottle (24-Ounce) (White) for $7.99 (list price $11.99)

ALPS Mountaineering Crescent Lake 0-Degree Sleeping Bag (Regular) for $43.19 (list price $53.99)

Tapirus Extendable Marshmallow Roasting 4 Camping Sticks | Durable Stainless Steel Equipment BBQ Skewers With Insulated Handles | Telescopic Campfire Forks Utensils For Smores, Hot Dogs & Shish Kebabs for $14.95 (list price $25.99)

OUTERDO Monocular Dual Focus Telescope Camping Wildlife Hunting Surveillance Sporting Events Traveling Scope Waterproof Optics Zoom Bright and Clear with 10 Magnification 16x52 for $12.99 (list price $18.89)

TaylorMade 2016 Tour Preferred Golf Balls (1 Dozen) for $27.99 (list price $39.00)

VicTsing 50ft Expanding Hose, Strongest Expandable Garden Hose with Double Latex Core, Solid Brass Connector and Extra Strength Fabric for Car Garden Hose Nozzle for $34.99 (list price $39.99)

Insulated Picnic Basket - Lunch Tote Cooler Backpack w/ Flatware Two Place Setting (Black & Red) for $25.99 (list price $31.04)

Ekogrips BBQ Oven Gloves | Best Versatile Heat Resistant Grill Gloves | Lifetime Replacement | Insulated Silicone Oven Mitts For Grilling | Waterproof | Full Finger, Hand, Wrist Protection | 3 Sizes for $18.27 (list price $57.99)

Lightning Nuggets Inc 0-47815-14175-7 12-Count Firestarters for $5.54 (list price $12.99)

Imarku BBQ Grill & Baking Mats, Durable , Heat Resistant, Set of 10 Non-Stick Grilling Accessories for $23.99 (list price $49.99)

TOOLS

TIWIN LED Light Bulbs 100 watt equivalent (11W),Soft White (2700K), General Purpose A19 LED Bulbs,E26 Base ,UL Listed, Pack of 6 for $19.99 (list price $23.99)

Kidde FA110 Multi Purpose Fire Extinguisher 1A10BC, 1 Pack for $19.98 (list price $42.99)

Sugru Moldable Glue - Black & White (Pack of 8) for $14.80 (list price $21.25)

5 Pack Ipow LED Battery-powered Wireless Night Light Stick Tap Touch Lamp Stick-on Push Light for Closets, Cabinets, Counters, or Utility Rooms,Cordless Touch Light,Batteris Not Included for $9.97 (list price $11.99)

Dimmable LED Desk Lamp, 4 Lighting Modes(Studying, Reading, Relaxing, Sleeping), 5 Level Dimming, 1 Hour Auto Timer, Touch Sensitive Control, Modern, - Piano Black for $29.97 (list price $109.00)

KEDSUM 200pcs Adhesive Cable Clips, Wire Clips, Car Cable Organizer, Cable Wire Management, Drop Cable Clamp Wire Cord Tie Holder for Car, Office and Home for $8.99 (list price $19.99)

GlowBowl A-00452-01 Motion Activated Toilet Nightlight for $10.40 (list price $24.99)

Mothers 07240 California Gold Clay Bar System for $14.24 (list price $15.37)

J5 Tactical V1-Pro Flashlight The Original 300 Lumen Ultra Bright, LED 3 Mode Flashlight for $12.95 (list price $29.95)

Oria Precision Screwdriver Set, 60 in 1 Magnetic Driver Kit with 54 Bits, Professional Electronics Repair Tool Kit for iPhone/ Cell Phone/ iPad/ Tablet/ PC/ MacBook and Other Electronics for $13.99 (list price $26.99)

SE MH1047L Illuminated Multi-Power LED Head Magnifier for $8.94 (list price $15.44)

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