Portal:Sandbox
From Wikipedia, the free encyclopedia
Arts · Biography · Geography · History · Mathematics · Philosophy · Science · Society · Technology
Portal Sandbox |
A science, from the Latin, scire, to know, is a body of knowledge that is constructed via observation, hypothesis, experimentation, and logic for the purpose of explaining and predicting events or behavior. Observation, experimentation and critical reasoning all play crucial roles in the advancement of scientific knowledge. A discipline is widely regarded as a science if its practitioners apply the 'scientific method'. According to falsificationists, this involves the formation of a testable hypothesis, followed by ongoing attempts to refute this hypothesis via critical reasoning, experimentation and observation. A hypothesis that has been rigorously tested under a wide variety of conditions, and which remains unrefuted, is tentatively accepted as a useful approximation to the truth, and attains the status of theory; future observations may yet refute it. |
Sandbox subportals |
||||||||||||||||||||
|
Selected article |
Teflon is the brand name of the polymer polytetrafluoroethylene (PTFE) discovered by Roy J. Plunkett (1910–1994) of DuPont in 1938 and introduced as a commercial product in 1946. It is a fluoropolymer but not a thermoplastic in the true sense. PTFE has the lowest coefficient of friction of any known solid material. It is used as a non-stick coating for pans and other cookware. PTFE is very non-reactive, and so is often used in containers and pipework for reactive chemicals. Its melting point is 327 °C, but its properties degrade above 260 °C. |
Selected biography |
Template:Nobel medal Santiago Ramón y Cajal (May 1, 1852 – October 17, 1934) was a famous Spanish histologist, physician, and Nobel laureate. He is considered to be one of the founders of modern neuroscience. His most famous studies were on the fine structure of the central nervous system. Cajal used a histological staining technique developed by his contemporary Camillo Golgi. Golgi found that by treating brain tissue with a silver chromate solution, a relatively small number of neurons in the brain were darkly stained. This allowed him to resolve in detail the structure of individual neurons and led him to conclude that nervous tissue was a continuous reticulum (or web) of interconnected cells much like those in the circulatory system. Using Golgi's method, Ramón y Cajal reached a very different conclusion. He postulated that the nervous system is made up of billions of separate neurons and that these cells are polarized. Rather than forming a continuous web, Cajal suggested that neurons communicate with each other via specialized junctions called "synapses". This hypothesis became the basis of the neuron doctrine, which states that the individual unit of the nervous system is a single neuron. Electron microscopy later showed that a plasma membrane completely enclosed each neuron, supporting Cajal's theory, and weakening Golgi's reticular theory. |
Selected picture |
Saturn V was a multistage liquid-fuel expendable rocket used by NASA's Apollo and Skylab programs. The largest production model of the Saturn family of rockets, the Saturn V was designed under the direction of Wernher von Braun at the Marshall Space Flight Center in Huntsville, Alabama, with Boeing, North American Aviation, Douglas Aircraft Company, and IBM as the lead contractors. It remains the most powerful launch vehicle ever brought to operational status, from a height, weight and payload standpoint, although the Russian Energia, which flew only two test missions, had slightly more takeoff thrust. In all, NASA launched thirteen Saturn V rockets between 1967 to 1973, with no loss of payload. The design payload was the manned Apollo spacecraft used by NASA for moon landings, and the Saturn V went on to launch the Skylab space station. The three stages of the Saturn V were developed by various NASA contractors, but following a sequence of mergers and takeovers all of them are now owned by Boeing. Each first and second stage was test fired at the Stennis Space Center located near Bay St. Louis, Mississippi. The facility was later used for the testing and verification of the Space Shuttle's Main Engines. |
Did you know... |
...that metolazone is a medicine used to treat congestive heart failure and hypertension? |
Sandbox Media |
Scientific American is a popular-science magazine, published monthly since August 28, 1845, making it the oldest continuously published magazine in the United States. It brings articles about new and innovative research to the amateur and lay audience.
|
Categories |
Astronomy | Chemistry | Earth Sciences | Physics Biology | Dentistry | Ecology | Medicine | Neuroscience | Nutrition | Pharmacy | Psychology | Veterinary medicine Related Engineering | History of Science | Mathematics | Technology | Computer Science | Cryptography |