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- For a topic outline on this subject, see List of basic topics in science
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Scientists maintain that scientific investigation must adhere to the scientific method, a process for properly developing and evaluating natural explanations for observable phenomena based on empirical study and independent verification. Science therefore bypasses supernatural explanations, it instead only considers natural explanations, and rejects arguments from authority.
Fields of science are commonly classified as either a Natural sciences which study natural phenomena or as a social sciences which study human behavior and societies. Mathematics is the language in which scientific information is best presented but more often it is the only way. Therefore whether mathematics is a science is a matter of perspective.
Fields of science can be further distinguished as pure science or applied science. Pure science is principally involved with the discovery of new truths with less (or no) regard to their applications. Applied science is principally involved with the application of existing knowledge in new ways.
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 is often used in containers and pipework for reactive chemicals. Its melting point is 327 °C, but its properties degrade above 260 °C. At this point gaseous fluorine compounds are released that are dangerous to humans.
Other polymers with similar composition are known by the Teflon name: fluorinated ethylene-propylene (FEP) and perfluoroalkoxy polymer resin (PFA). They retain the useful properties of PTFE of low friction and non-reactivity, but are more easily formable. FEP is softer than PTFE and melts at 260 °C; it is highly transparent and resistant to sunlight.
Craniometry is the technique of measuring the bones of the skull. Craniometry was once intensively practiced in anthropology and ethnology. Human skulls can be classified into three main categories based on cephalic index: dolichocephalic: long and thin; brachycephalic: short and broad; mesocephalic: intermediate length and breadth.
- ...that the gestation period of the ring-tailed lemur (pictured) is approximately 146 days?
- ...that the Late November 2006 Nor'easter caused winds up to 80 mph (70 knots) in the Outer Banks of North Carolina, the earliest snowfall on record for Savannah, Georgia and Charleston, South Carolina, as well as Charleston, South Carolina's only occurrence of thundersnow on record?
- ...that the Rufous-crowned Sparrow, a medium-sized sparrow of the southwestern United States and Mexico, has a subspecies endemic to the Todos Santos Islands that has not been seen since the 1970s?
- ...that the Christmas 1994 Nor'easter led to wind gusts of 99 mph/86 knots in Massachusetts, and briefly formed an eye?
- ...that the Northern Red-legged Frog is a near-threatened species, whose male defends breeding pond territory with nocturnal displays?
