Tuesday, June 26, 2007

Scientific Methods

The scientific method seeks to explain the complexities of nature in a replicable way, and to use these explanations to construct useful predictions. It provides an objective method to find solutions to problems in a number of scientific and technological fields. Often scientists have a predilection for one outcome over another, and scientists are conscientious that it is vital that this preference does not bias their interpretation. A strict following of the scientific method attempts to minimize the pressure of a scientist's bias on the outcome of an experiment. This can be achieved by correct experimental design, and a thorough peer assessment of the experimental results as well as conclusions of a study.

Scientists use models to refer to a explanation or depiction of something, specifically one which can be used to construct predictions that can be tested by experiment or observation. A hypothesis is a disputation that has been neither well supported nor yet ruled out by experiment. A theory, in the context of science, is a logically self-consistent model or framework for recitation the behavior of certain natural phenomena. A theory typically describes the behavior of much broader sets of phenomena than a hypothesis — commonly, a large number of hypotheses may be logically bound together by a single theory. A physical law or law of nature is a scientific generalization based on a adequately large number of empirical observations that it is taken as fully verified.

Saturday, June 23, 2007

Goldfish

The goldfish, Carassius auratus, was one of the earliest fish to be domesticated, and is still one of the most usually kept aquarium fish and water gardens. A comparatively small member of the carp family ,which also includes the koi carp and the crucian carp, the goldfish is a domesticated version of a dark-gray/brown carp native to East Asia that was introduced to Europe in the late 17th century. The mutation that gave rise to the goldfish is also known from other cyprinid species, such as common carp and tench. Goldfish may grow to a maximum length of 23 inches (59 cm) and a maximum weight of 9.9 pounds (4.5 kg), although this is rare; few goldfish reach even half this size. In optimal conditions, goldfish may live more than 20 years (the world record is 49 years), but most household goldfish generally live only six to eight years, due to being kept in bowls.A group of goldfish is known as a troubling.

Sunday, June 17, 2007

Coppicing

Coppicing is a conventional method of woodland organization in which young tree stems are cut down to a low level. In subsequent growth years, many new shoots will come out and after a number of years the cycle begins again and the coppiced tree, or stool, is ready to be harvested again.Typically a coppice woodland is harvested in sections, on a rotation. In this way each year a crop is available. This has the side-effect of as long as a rich variety of habitats, as the woodland always has a range of dissimilar aged stools growing in it. This is helpful for biodiversity. The cycle length depends upon the species cut, the local custom, and the use to which the product is put. Birch can be coppiced for faggots on a 3- or 4-year cycle, whereas oak can be coppiced over a 50-year cycle for poles or firewood.

Monday, June 11, 2007

Urban archaeology

Urban archaeology is a sub regulation of archaeology specializing in the material past of towns and cities where long-term human habitation has often gone a rich record of the past. Humans generate waste. Large concentrations of humans manufacture large concentrations of waste. Feces, kitchen waste, broken objects etc. all need to be liable of. Small numbers of people can dispose of their waste locally without heartening vermin or endangering their health. Once people began to exist together in large numbers, around five thousand years ago, such methods began to become impractical. Material would be brought into the new settlements but would rarely be taken out again.

Wednesday, June 06, 2007

Krill fishery

Krill fishery is the commercial fishery of krill, small shrimp-like marine animals that live in the oceans world-wide. Estimates for how much krill there is vary wildly, depending on the methodology used. They range from 125–725 million tonnes of biomass globally. The total global harvest of krill from all fisheries amounts to 150 – 200,000 tonnes annually, mainly Antarctic krill (Euphausia superba) and North Pacific krill (E. pacifica).
Krill are rich in protein (40% or more of dry weight) and lipids (about 20% in E. superba). Their exoskeleton amounts to some 2% of dry weight of chitin. They also contain traces of a wide array of hydrolytic enzymes such as proteases, carbohydrases, nucleases and phospholipases, which are intense in the digestive gland in the cephalothorax of the krill.
Most krill is used as aquaculture feed and fish bait; other uses comprise livestock or pet foods. Only a small percentage is prepared for human consumption. Their enzymes are interesting for medical applications, an expanding sector since the early 1990s.