Posted on 20 July 2011.
Posted in What Is/Are...?Comments Off
Posted on 16 July 2011.
A bubble is a globule of one thermodynamic phase inside of another, like a gas in a liquid. We commonly find bubbles in boiling water, carbonated sodas, sea foam, and gas pockets in glass. Learning about bubbles can teach us about many concepts, like shape, transparency, mirrored surfaces, colors, and flexibility.
Bubbles are produced by the scientific process of nucleation. Nucleation occurs when a small pocket of one thermodynamic phase forms inside of another. In bubbles, the thermodynamic phase of a gas forms inside of the thermodynamic phase of a liquid. However, pure water is not stable enough to produce a lingering bubble. We use soap to stabilize bubbles, allowing them to linger for longer. Many incorrectly believe that soap increases water’s surface tension. This is not true. In fact, soap decreases water’s surface tension. Soap does not strengthen bubbles, it merely stabilizes them.
We use bubbles in many ways, both practical and fun. We use bubbles in ultrasounds to help us better see babies. We use bubbles to better understand mathematical concepts, like minimal surface area. Performance artists use bubbles for their aesthetic properties. We also use bubbles as toys. Children have been playing with bubbles since the 1600s. Toy stores sell about two hundred million bottles of bubble mixture every year.
When disturbed, bubbles pulsate, or rapidly oscillate in size. These oscillations destabilize bubbles, leading them to eventually tear apart. The popping of bubbles below produces most of the liquid sounds that we hear.
If you would like to learn more about bubbles, you can do so by observing them yourself. Enjoy educational, fun homemade bubbles by mixing your own bubble solution. Simply combine ½ a cup of dishwashing liquid, two teaspoons of sugar, and two cups of water to make bubbles whenever you want.
Posted in Water UseComments Off
Posted on 08 July 2011.
What is an isolation tank? You may have heard people talking about isolation tanks recently, but you may not know what they are yourself. An isolation tank is a lightless, soundproof tank in which a person floats in skin temperature salt water. Isolation tanks employ sensory deprivation as a tool for meditation and relaxation. Some consider isolation tanks a form of alternative medicine. Isolation tanks go by many names, such as float tanks, sensory deprivation tanks, and floatation baths.
Isolation tanks are designed to cut off all stimuli. The water in isolation tanks is filled with Epsom salt, which increases the water’s salinity and density, allowing users to float more easily with their faces above the water. Because the users’ ears float below the water, hearing is reduced. Other users use ear-plugs to further cut off sound. Users float with their arms by their sides, reducing skin sensation. To reduce smell, the water is treated as little as possible. The water temperature is carefully matched with the air temperature, cutting down one’s feeling of having a body boundary. In short, the isolation tank is designed to eliminate as many stimuli as possible.
People usually use the isolation tank while naked. While users can technically wear swimsuits, this is discouraged because the elastic on swimsuits can uncomfortably compress skin, producing extraneous negative stimuli. Because the water should be altered by external forces as little as possible, users must bathe before entering the tank. After their isolation tank session, users must bathe again to cleanse their skin of the Epsom salt. For this reason, a shower is usually installed in the same room as the tank. This allows the user can switch directly from the shower to the tank and the tank to the shower.
The isolation tank was created in 1954 by medical practitioner John C. Lilly. John C. Lilly, a trained psychoanalyst, wanted to experiment with sensory deprivation. Several theories about sensory deprivation were circulating in Lilly’s. These theories held that the brain could go to sleep if all stimuli were cut off to it. Lilly decided to test these theories with the isolation tank, an experimental environment that would isolate the individual from external stimulations. He used this experimental environment to study awareness and consciousness. Experimenters at other universities continue his studies today. What is an isolation tank? A relaxation technique whose benefits are still being researched today.
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Posted on 05 July 2011.
There are many, many different types of bodies of water. Some bodies of water occur naturally. Others, like reservoirs and harbors, are man-made. Although water formations that move around, like rivers and streams, aren’t always considered bodies of water, there is no other English term for moving bodies of water, so they are typically grouped with other bodies of water. Some bodies of water are less well-known and culturally and geographically limited in scope. For instance, the Spanish have named the “arroyo,” a creek that temporarily fills with water after a heavy rain or a rainy season. The Australians have named the “billabong,” a pool of water that forms when a river changes its course. Some major bodies of water include oceans, seas, and rivers.
The largest bodies of water are oceans, enormous pools of saltwater. Oceans are continuous bodies of water that divide into smaller seas. Although interconnected, we typically describe oceans as separate. Earth’s oceans run about two miles deep. They are home to about 230,000 known marine species, and perhaps ten times that number of unknown marine species. Although interconnected into one global saltwater body that oceanographers sometimes call the “World Ocean,” Earth’s oceans are usually described as five separate bodies of water. This allows us to specify which part of the World Ocean we’re talking about. These five oceans are the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean, and the Arctic Ocean.
Seas are large bodies of water that are usually connected with oceans. The term “sea” is sometimes incorrectly used as a synonym for the term “ocean.” However, oceanographers see seas and oceans as two different kinds of bodies of water. Seas are smaller saltwater bodies that are usually interconnected with oceans, but can sometimes be disconnected from oceans. For instance, the Caspian Sea is in fact a saltwater lake.
Rivers are moving, usually freshwater bodies of water. They typically flow into other bodies of water, like oceans, seas, lakes, and other rivers. However, they can sometimes flow into the ground or dry up before reaching other bodies of water.
Posted in Water and the EnvironmentComments Off
Posted on 04 July 2011.
Storm surge is the coastal flooding produced by storms like tropical cyclones. Storm surge is caused by high winds that push on the ocean’s surface. These winds pile water up higher than ordinary sea levels, producing flooding.
The National Hurricane Center defines storm surge as water’s height above what astronomical tide levels would predict. In layman’s terms, storm surge is the difference between how much tide we predict and how much we observe water to rise. In non-scientific contexts, people call “storm surge” “storm tide.” This term denotes the weather effects that accompany storm surge, including water rises, tide, piled-on waves, and freshwater flooding.
The weather effects of storm surge are often dangerous. When people die during tropical cyclones, they typically die from surge-related conditions. Storm surge can be particularly devastating during high tide, as this makes it more difficult to predict the amount of surge that will occur. While the SLOSH (Sea, Lake, and Overland Surges from Hurricanes) model tries to predict how much storm surge a tropical cyclone will produce, weather forecasts are only accurate on short-term bases.
Storm surge is caused by environmental factors that accompany storms, including pressure, direct wind, waves, and rainfall. Tropical cyclones’ pressure raises water levels in places where there’s low atmospheric pressure. Water levels increase at downwind shores. Strong winds produce strong waves that travel in the direction that they move. Although surface waves don’t carry much water in the middle of the ocean, they can carry a lot of water to shore, and fast. Hurricanes can pour out a foot of rainfall in one day.
The deadliest storm surge–and the deadliest natural disaster–of all time was produced by the Galveston Hurricane of 1900. When this hurricane struck Galveston, Texas, its storm surge killed nine thousand people. The highest historically noted storm surge was produced by the 1899 Cyclone Mahina in Bathurst Bay, Australia, and was noted at forty-three feet high. In the United States the highest recorded storm surge was produced by Hurricane Katrina in 2005, and was noted at twenty-five feet high.
Places that frequently suffer from coastal flooding manage surge by monitoring it. Meteorological surveys warn us when hurricanes and severe storms are coming. In places that frequently suffer from storm surge, such as the Netherlands and the United States, people construct dams and floodgates. These storm surge barriers allow free passage when open but close when threatened with storm surge. Some communities, as in the Netherlands, create floating housing communities along wetlands. By floating, these communities can better accommodate rising tides.
Posted in Water and the EnvironmentComments Off
Posted on 03 July 2011.
The highest waterfall in the world is Angel Falls, located in the Guyana highlands of Venezuela. It plunges 979 meters, or 3,212 feet–for reference, that’s fifteen times higher than Niagara Falls. The Angel Falls comprise forty-seven drops.
Angel Falls is located in Canaima National Park, a UNESCO World Heritage site. Canaima National Park is located in the southwest of Venezuela and to the south of the Orinoco River. The falls are deeply enmeshed in jungle and can only be reached by flight or by river trips during the rainy season. Angel Falls is dangerous to climb or descend from, as the falls create their own weather, including wind gusts and spray waves. Much of the waterfalls’ waters dissipate into mist before landing in the “Devil’s Canyon.” Those waters that do land feed into the Kerep River.
The identity of the first European to have seen the highest waterfall is unclear. Sixteenth-century explorer Sir Walter Raleigh is widely cited as the first European to have seen Angel Falls. However, the waterfall was not widely known until Jimmy Angel’s famous 1933 flight over the waterfall in search of gold. The waterfall’s height was first officially measured by National Geographic in 1949. Today the highest waterfall is a hot tourist spot, although its summit is still difficult to reach.
The highest waterfall was named in English as “Angel Falls” after Jimmy Angel, the twentieth-century explorer who was the first aviator to fly over the waterfall in a plane. Jimmy Angel’s famous flight culminated in an emergency landing atop the fall, where he abandoned his plane, trekking down the falls through the jungle for eleven days before reaching civilization. His plane remained at the top of the falls for thirty-three years, when it was brought down by helicopter. His plane is now on show in the aviation museum of Maracay.
The highest waterfall was in English called “Angel Falls” after Jimmy Angel, whose emergency landing atop the falls’ summit popularized the site. However, the waterfalls’ name has been disputed recently. In 2009 the Venezuelan president Hugo Chavez declared his wish to rename the waterfall with its indigenous Pemon name, “Kerepakupai Meru,” which means “waterfall of the deepest place.” Chavez later elaborated on his beliefs, saying, “This [waterfall] is ours, long before Angel ever arrived there… This is indigenous property.” Chavez later clarified that he would not enforce this name change.
Posted in Water and the EnvironmentComments Off
Posted on 02 July 2011.
Nowadays, after the growth of industries, clean drinking water doesn’t naturally occur. Scientists continually discover contaminants in fresh water sources and correlates between drinking contaminated water and health problems. Because we need water but it is impure, we have learned to treat water. However, the history of water filtration is not a recent one; water filtration began over 4000 years ago.
Some milestones in the history of water include the invention of the microscope, the advent of municipal water treatment, the use of chlorine to purify water, and the Clean Water Act of 1972.
The earliest recorded attempts to filter water date back to 2000 BC, to early Sanskrit writings of water purification methods. These methods include boiling water and filtering water through sand or charcoal filters. The Sanskrits’ biggest motive was to make water taste better, because they assumed that good-tasting water would also be clean. People didn’t yet realize that contaminated water caused disease, and they certainly couldn’t test for diseases in water.
In 1590, the Dutch glasses-makers Zaccharias and Hans Janssen invented the forerunner to modern-day microscopes. A century later, Anton van Leeuwenhoek, “the father of microscopy,” advanced the Janssens’ invention to the extent that scientists could now view tiny living particles in water that had previously been thought clean. In nineteenth-century London, city officials first linked cholera to bad water quality. John Snow, a British scientist, confirmed cholera bacteria in the Broad Street Pump’s water, proving that taste and visual clarity doesn’t prove water’s pureness. After this event, the British government insisted upon filtering city water, a precedent for municipal water systems. The British municipal water system cleaned water partly by treating it with chlorine.
In the 20th century, people increasingly agreed that every person has the right to clean water. The Clean Water Act (CWA) of 1972 made it a law that every city in the United States must have a water treatment plant. The CWA forced industrial plants to become environmentally friendly and renewed interest in water filtration, making clean water a national goal. Today the history of water continues as we strive to bring clean water to places that still need it.
Posted in Water UseComments Off
Posted on 01 July 2011.
The history of water treatment has been marked by slow, gradual discoveries that coincided with human development. While water filtration technology only became successful and widely used in the 20th century, the history of water treatment can be traced back to thousands of years ago.
Man has sought pure, clean water for as long as he has been on Earth. The earliest recorded mention of water filtration and purification can be found in Sanskrit writings from about 2000 B.C.E. These writings state that “impure water should be purified by being boiled over a fire…or it may be purified by filtration through sand and coarse gravel and then allowed to cool.” This demonstrates that even in some of the earliest civilizations the basics of water purification were known. There is also some evidence that the ancient Egyptians used wick siphons for water clarification. Later, following the tutelage of Hippocrates, the Greek and Roman empires used cloth bags and additives such as pounded barley to filter out bad tastes in water.
After Sir Francis Bacon renewed interest in filtration in 1627, a number of important scientific discoveries deeply affected the history of water treatment. Around 1690, Anton van Leeuwenhoek invented an early version of the modern microscope, which allowed scientists to more effectively study particles in water. Meanwhile, in Italy, Lucas Antonius Portius invented the first effective sand filtration system using multiple perforated compartments and large grains of sand. These two inventions allowed people in 19th century Britain to examine disease-causing bacteria in water and create one of the world’s first municipal water treatment systems.
In the early 1900s, English physicians discovered that chlorine was very effective in eliminating disease from water, and chlorination of public water systems began. The United States and other countries soon followed suit, and in 1972, the Environmental Protection Agency passed the Clean Water Act, requiring cities to filter public water. Today, amid growing concerns about the safety of water fluoridation and chlorination, individual households have begun to install filtration devices to taps, showerheads, and entire plumbing systems.
The history of water filtration is still being written. While individuals in America and other countries continue to improve the quality of household water, many people in developing countries lack the ability to properly filter their water. The challenge moving forward will be in improving water filtration for all of humanity.
Posted in SanitationComments Off
Posted on 29 June 2011.
Every year, around two thousand to ten thousand shipping containers fall off the vessels they are transported on and sink to the ocean floor. No one knows the exact number of shipping containers on the ocean floor, as shipping companies are not required to report fallen containers. Most of these companies litter the shipping lanes that crisscross our oceans. Many worry that these artificial reefs of shipping containers on the ocean floor will force sea creatures to move from one ecosystem to another, thereby damaging the delicate undersea balance.
Posted in More About WaterComments Off
Posted on 28 June 2011.
Another irrigation system, drip irrigation, waters more precisely. Drip irrigation, also known as micro-irrigation or trickle irrigation, uses very thin plastic tubes, usually called drip tape, with small holes every few feet. These tiny holes usually release only a drop of water at a time. The grower lays the drip tape across the field alongside the plants and matches the small holes in the tape with the plants. When water is pumped through the drip tape, the drip system slowly waters each plant. This method prevents water loss to runoff. The system pumps the water directly into the ground, preventing the diseases that can occur when leafy material touches water. The drip tape is often buried an inch under the earth in order to protect the tape from tractors and to decrease the amount of water lost to evaporate. However, a drip irrigation system is expensive, and may cost over a thousand dollars per acre. Also, the drip tape can be easily clogged, requiring maintenance.
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