Feb 23
adminEntertainment
Every kind of sound is produced by vibration. The sound source may be a click of a button, an automobile horn, or a hounding wolf. These waves travel out in all directions, expanding in balloon like fashion from the source of the sound. The vibrations from the source disturb the air in such a way that sound waves are produced. Vibrations that are perceived as sound, if the waves happen to reach someone’s ear, they set up. Sound, depends on three things. There must be a vibrating source to set up sound waves, a receiver to detect them, a medium to carry the waves, and. Sound waves cannot travel through a vacuum. There is an age-old question concerning the definition of sound. If a lamppost falls in a road far from any sound detector (such as a human ear or a microphone), does the lamppost’s crash make any noise? The answer, obviously, depends on how sound is perceived. If it is thought of as the waves that are carried by the air, the answer is yes—wherever there are sound waves there is sound. Whatever it is, some part of it is vibrating while it is producing sound
Feb 17
adminEntertainment
The film on which images are made is a strip of cellulose acetate that is coated with a light-sensitive emulsion that retains images. It is generally classified by its width. Most theatrical motion pictures are photographed in 35-millimeter or 70-millimeter (wide-screen) film. Virtually all commercial production is done in 16-millimeter film. Amateur and experimental filmmakers often use 8-millimeter or 16-millimeter film. The larger the size of the film, the better the quality of the image obtained. Film raw stock is also graded according to its sensitivity to light. A fast, or high-speed, film requires less light to retain an image than a slow, or low-speed, film. Since the grains of emulsion on fast film are larger than that on slow film, fast film generally has a grainier appearance when projected. Fast film provides a low degree of contrast between black and white tones; slow film provides a greater range of brightness and darkness. In early Technicolor process used three separate films in the camera, each recording the image of a primary color. After development, the three negatives were printed together on a composite color print. All color film production today, however, is done with integral-tripack emulsions, for which only one film is needed.
Feb 11
adminEntertainment
The chief doorways of the world of international commerce are its harbors and ports. Through them pass cargoes and travelers from one part of the globe to another. A harbor is any sheltered body of water where boats or ships may moor or anchor. A port is an installation that has been built around a harbor with facilities for loading and unloading such vessels. Ordinarily a harbor, either natural or man-made, must exist before a port facility can be set up. Some large harbors—San Francisco Bay on the California coast, for example—are used by several ports. Some ports, such as Chicago, Ill., on Lake Michigan, are served by several small harbors. The major requirements of a good harbor are direct access to the open water and sufficient depth for vessels to enter and exit safely. Ocean harbors are commonly 40 feet deep or more. The harbor should be well protected against storms and large waves. The bottom of the harbor should provide good holding ground for anchors—it must not be too rocky, too sandy, or too muddy. The harbor should also be spacious enough for ships to ride at anchor and to maneuver. Currents and tides must not be excessive.
Feb 08
adminEntertainment
Life to future plant is passed on generations by seeds. Flower works to make seed and also vice versa. One purpose of the flower for its beauty is this. Insects and hummingbirds are attracted by the Color and perfume of a flower to aid in the pollination. Only certain insects and no others are admitted by some flowers. The stamens, pistil, and ovary are the chief seed-making parts. To protect these parts, many interesting flower shapes have been developed. If one understands its structure and how each part helps in the work of seed making flower’s beauty and perfection of form may be enjoyed more completely. A typical flower has four sets of organs. From the outside to the center, they are: petals, pistils, sepals and stamens. The leaflike sepals make up the calyx, or “cup.” the corolla is formed by the petals, or “little crown.” The perianth is formed by the calyx and the corolla together. A small leaf below the flower, when present, is the bract. Awns are stiff bristles that terminate some flower parts. There are no sepals or petals at all in the simplest flowers. a single pistil which is surrounded by the small flowers of grasses consist commonly of three stamens surrounding. They are said to be naked. Some flowers have no petals that are they are apetalous.
RSS