Navajo Rugs Crude Oil Kaleidoscopes Titanium Dental Implants
Rug weaving is a traditional art practiced by the navajo, an indian nation located in the united states where colorado, new mexico, utah, and arizona intersect. They originally wove blankets and clothing. Then, in the early 1800s, they began weaving rugs for sale. While many weavers create contemporary designs, navajo rugs typically feature bold geometric patterns. The wool-preparation and weaving techniques developed by the weavers' ancestors have been proudly passed down from generation to generation. Everything in a navajo rug comes from nature, starting with fleece--  raw wool sheared from a sheep. Working a handful at a time, the weaver removes the mats and tangles and places the wool on carders-- wooden paddles with metal teeth. By pulling one carder against the other, she straightens the wool fibers, lining them up in the same direction. This prepares them to be spun into one continuous strand of yarn. After three or four pulls, she flips the carders to straighten the fibers on the underside. Then she rolls up the fleece and adds it to the other rolls in the spinning pile. She spins the fleece one roll at a time with the traditional spindle that she lays against her thigh and rotates towards her with one hand. This movement twists the carded roll of fleece into a strand. When she reaches the end of the roll, she connects another and resumes spinning and keeps repeating this process until she's produced one long, continuous strand from about 50 rolls. Then she respins the strand to thin it out to the final weaving size. When she's done, she checks the entire length of the strand, pulling on the thicker areas to thin them out so that the entire strand is a consistent size from one end to the other. Here you can see the difference in thickness between the first spinning and the second. To infuse her wool with color, she prepares natural dyes-- sunflowers for yellow, walnuts for tan and brown hues, and cactus bugs for bright red. She puts the bugs in a stocking and soaks them in warm water overnight. Then, she submerges them in a pot of water, pours in the presoak water, as well, and simmers for 45 minutes to an hour and a half, depending on how vibrant she wants the red dye to be. Meanwhile, she soaks the yarn in warm water for at least a half-hour to open up the fibers so that they'll absorb the dye. After wringing out the yarn, she immerses it in the pot of hot dye and simmers for at least 45 minutes, depending on the amount of bugs, water, and wool. She stirs frequently to ensure it dyes evenly throughout. It's the same process with plant dyes, except that she doesn't presoak the plants overnight before boiling them in water. The shade of color depends on the ratio of plants to water during dye preparation, then of dye to the quantity of wool. Proportionally more plants than dye, the darker the shade. Proportionately less, the lighter the shade. Sunflowers and walnuts are just two of many plants the navajo have traditionally used to produce a rainbow of dyes for their textiles. With her wool now spun and dyed, the weaver picks up her weaving comb and begins. Navajo ancestors used trees as the sides of their looms. Today's weavers make looms from lumber or metal pipes. After stringing tight, vertical strands of wool called the warp, she uses a flat, handmade stick called a batten to pry a wide enough opening through which to pass her hand with the colored weaving wool. She weaves horizontally in and out between the warp first in one direction, then in the other. Then, she packs down the wool tightly with her comb so that the warp doesn't show. She mostly eyeballs the emerging unique pattern, occasionally counting vertical strands to calculate the symmetry, a signature feature of traditional navajo rugs. Crude oil, also called petroleum, is unprocessed oil found deep in the ground. It forms naturally from decomposed, prehistoric plants and animals. The color can range from clear to black, the consistency from very watery to very thick. Oil companies drill wells deep into the ground then install pumping units to draw up the fluid that contains crude oil and salty water. This oil field in central california has 6,000 producing wells. The pumping units can run 24 hours a day. However, a sensor triggers them to pump only when the fluid flow stops. Here's what goes on inside the well. With each downstroke, the pumping unit pushes a steel rod down the steel tube lining the well. With each upstroke, the rod rises, and the pressure difference between the fluid on the outside and fluid on the inside opens a ball-shaped valve plugging the bottom, letting the fluid flow up the tube. Another valve at the top releases the fluid out of the well. To drill a new well, workers first erect a drilling rig at the site then hoist a giant pipe with a drill bit on the end. They feed this drill pipe through the center of a spinning disk called a rotary table. As the table turns, the drill pipe turns, its weight bearing down and boring a hole through the ground. Once the drill pipe descends its full 30-foot length, they connect another pipe then keep repeating with subsequent drill pipes until they bore into the reservoir containing fluid. Throughout the drilling process, they pump a mud mixture down the drill pipe. It comes out the drill bit at the end, hits the bottom of the hole, then backs up to the top, bringing the drilled-out rock with it. After lining the well with a steel tube to keep the walls from collapsing inward, they mount the pumping unit and install the valves we saw in the model. The pumping unit pushes the rod up and down through the well head at the surface. As a safety measure, workers take readings to check the air for any hazardous underground gases that may be exiting the well. Once they determine the area is safe, they draw a sample of fluid to test the well's water-to-oil ratio. The typical ratio is 90% water to 10% oil. The fluid from each well exits via a pipe, and the pipes from all the wells feed a main line leading to a gas-removal vessel. The fluid contains carbon dioxide, hydrogen sulfide, and natural gas. They naturally rise to the top of the vessel and exit via a pipe which runs to the company's gas-treatment plant. There, equipment removes and treats the hydrogen sulfide, transforming it into sulfur, which a local farm buys to use as fertilizer. The natural gas and co2, meanwhile, are piped to another area, where they fuel the company's steam generator. The generator boils the water extracted from the fluid to produce steam. The company injects steam into the wells to heat the fluid, thinning it so that it flows faster. Once gasless, the fluid is piped to the treatment plant that extracts the salty water. In this big tank, appropriately called the free-water knockout, the separation of oil and water happens naturally, the oil floating to the top. However, to hasten that natural process, they add a chemical called an emulsion breaker. The extracted water exits via a pipe leading to the steam generator. The oil goes to a clarification tank in which a chemical process filters out sand, which the fluid brought up from the reservoir. The emulsion breaker added in the previous tank continues to extract water. By the end, when the ratio is 98% oil to 2% water or better, the crude oil is ready to sell. Built-in meters give instantaneous water-content readings. As an additional quality-control measure, however, the company also draws samples for analysis in its onsite lab. In fact, there's testing throughout production to ensure sufficient water is being extracted at each phase of processing. Refineries buy crude oil as a raw material for producing gasoline, asphalt, plastics, and many other products. Invented in the early 19th century by a scottish scientist studying light, the kaleidoscope can still compete when it comes to producing stunning visual effects. Peer inside and witness dazzling geometric images produced as mirrors multiply objects. The images are spectacular and fleeting, each one lasting just seconds before the next appears. Many years after its invention, the kaleidoscope is still worth looking into. To make a kaleidoscope, this craftsman starts with a mirror sheet that has adhesive backing. He scores it to create long and narrow rectangles and gently breaks it along the scored lines. The mirror's reflective coating is on the front instead of the underside. A mirror like this produces sharper reflections than a regular household mirror. He slices the adhesive backing to separate the mirrored rectangles. He snaps off the scored ends, creating perfectly linear edges. Next, he peels backing from a strip of black-out felt paper and wraps it around a glass rectangle. This felt-wrapped glass will be the third wall of a two-mirror system-- one with a triangular configuration. He removes the adhesive film from the mirrors then builds the triangles with the mirrors' reflective surfaces facing inward towards the felt-wrapped rectangle. This arrangement will reflect objects to create a circular image known as a mandala. He aims the mirror system at a light box with a two-line drawing in it. One line is curved, and the other is straight. Peering into it, he adjusts the alignment of the mirrors until the lines morph into a five-point star. This means the corners of the mirror triangle are precisely 36 degrees and it is multiplying images correctly. He hot-glues the mirrors to the opaque part and applies metal tape to the top seam to complete the kaleidoscope mirror system. Over in the art department, the artist assembles decorative objects against a black background in an acrylic cell. With every placement, she checks the effect through the triangular mirror system. She glues dichroic glass onto the backdrop. It's a kind of glass that's been treated with metal oxides, and it appears to have different hues. Other objects include jewelry parts, colored wire, buttons, and even paper clips. She follows no specific design but works freestyle. While she glues some down, she leaves others loose to simply tumble around. A sprinkle of tiny beads completes the grouping. As the mirror system multiplies these objects, they will create the mandalas. These are photographs of actual mandalas, and they'll be used to decorate the outside of the kaleidoscope. The other member of the team now applies an acrylic adhesive to the rim of the cell and presses a clear lid onto it. The lid fuses to the cell body. But it's not yet completely sealed. There's a tiny hole in the side of the cell through which he now dispenses heavy mineral oil. Submerged in mineral oil, the objects will float and move through the cell for greater effect. He plugs the hole with an acrylic adhesive and screw. He is now ready to assemble all the parts of the kaleidoscope. He slides the mirror system into a heavy cardboard tube decorated by the mandala photos. He cushions the mirror system with foam, and this stabilizes it. He installs a metal eyepiece and glass lens on one end of the kaleidoscope tube. He slides the object cell into a protective metal cage that rotates. He places a transparent glass disk over the cell. He applies adhesive to the cage and inserts the assembly into the other end of the kaleidoscope tube. This kaleidoscope is now ready for a viewing. Light passes through the object cell, illuminating the trinkets. Reflections bounce off the mirrors to create one spectacular illusion after another. Two centuries after its invention, the view through the kaleidoscope still fascinates. The ancient mayans hammered seashells into their jaws to replace missing teeth. Those seashells were likely the first dental implants. Today, titanium tooth implants fill the gaps nicely, and, usually, the patient's jawbone will actually bond to them. In the middle of the 20th century, it was discovered that titanium is a metal that bonds with bone. It revolutionized restorative dentistry, making enduring tooth implants possible. To make these implants, they start with a solid titanium rod. This 13-foot rod will be used to make more than 200 implants. The technician inserts the rod in a long tubular device that keeps it straight as it feeds to a lathe system. The titanium rod spins as computerized tools slim it down and cut threads into it. These threads will help anchor the implants in the patient's jaw. The lathe pushes the rod out and then pulls it back in repeatedly to facilitate the shaping process. A tool now grips the implant while another cuts it to length. Then, a computerized drill hollows out the implant and carves threads inside for attaching the ceramic tooth. In minutes, a solid, metal cylinder becomes a hollowed and threaded implant. A robot now retrieves the implant from the clutches of another one. It transfers it to a cleaning station and then over to what's known as a vision measuring system. Here, a camera takes pictures of the implant from all angles and sends the images to a computer for analysis. The computer confirms the dimensions are exactly right. Then, the robot collects the implant and places it into a slot in a tray. Once filled with implants, a technician screws a mesh lid on the tray and slides it into a metal basket. The basket positions them for cleaning in a special washing machine known as a vapor degreaser. Inside, solvent vapors envelop the parts to clean off residual lubricant oils used during the cutting process. A robot transfers an implant to a holding device. The device secures the implant for the next robot to press a plastic collar onto it. This collar is temporary. It will serve as a mask to protect the outside of the implant as the top undergoes a process of colorization. A robot places the implant upside down in a mild acid. They apply an electrical charge. Different colors will appear at different voltages to color-code the part and indicate the diameter. The process is called anodizing. A robot now pulls off the masking collar. It transfers the implants to another tray and screws them onto it. This keeps them from falling off as machinery turns the tray upside down to immerse the implants in acid and anodize the exterior. This time, the anodizing serves another purpose. It changes the surface to make it more porous. This will improve the bonding of the patient's jawbone to the implant. The implant sparkles in the solution as it undergoes a transformation. Here's the new porous surface magnified by a microscope. A robot transfers the dental implants to another tray. They're now ready for a final cleaning. A technician puts a lid on the tray and lowers it into a tank full of hot, purified water. A generator sends high-frequency sound waves into the water, creating bubbles and waves that gently scrub the implants. After sterilization, these titanium dental implants are ready to take root in human jaws. The clinician screws the implant into the patient's jawbone and then secures a made-to-match ceramic tooth to it. Over time, bone will fuse to this artificial tooth, providing a long-lasting tooth replacement and giving the patient a reason to smile.