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Sun Gun Telescope
Sun Gun Telescope, as featured in the August 1999 issue of ''Scientific American'' magazine, was designed so that large groups of people can view the sun safely - in particular it was created as a way to encourage children to become interested in astronomy. With this safe and portable device, both amateur science enthusiasts and professionals alike can observe sun spots. Bruce Hegerberg designed the Sun Gun from a 60 mm diameter 900 mm fl. optical tube which is mounted inside a 3-inch PVC which is in turn connected to a 20-inch plastic flower planter. A rear projection screen is then mounted on the top of the flower planter. The entire Sun Gun can be made from items easily found at most local hardware stores. The scope itself is an inexpensive 60mm refractor available from many sources. See also * List of telescope types The following are lists of devices categorized as types of telescopes or devices associated with telescopes. They are broken into major classifications w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific American
''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it is the oldest continuously published magazine in the United States. ''Scientific American'' is owned by Springer Nature, which in turn is a subsidiary of Holtzbrinck Publishing Group. History ''Scientific American'' was founded by inventor and publisher Rufus Porter (painter), Rufus Porter in 1845 as a four-page weekly newspaper. The first issue of the large format newspaper was released August 28, 1845. Throughout its early years, much emphasis was placed on reports of what was going on at the United States Patent and Trademark Office, U.S. Patent Office. It also reported on a broad range of inventions including perpetual motion machines, an 1860 device for buoying vessels by Abraham Lincoln, and the universal joint which now can be found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy
Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest include planets, natural satellite, moons, stars, nebulae, galaxy, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond atmosphere of Earth, Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonian astronomy, Babylonians, Greek astronomy, Greeks, Indian astronomy, Indians, Egyptian astronomy, Egyptians, Chinese astronomy, Chinese, Maya civilization, Maya, and many anc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sun Spot
Sunspots are phenomena on the Sun's photosphere that appear as temporary spots that are darker than the surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic flux that inhibit convection. Sunspots appear within active regions, usually in pairs of opposite magnetic polarity. Their number varies according to the approximately 11-year solar cycle. Individual sunspots or groups of sunspots may last anywhere from a few days to a few months, but eventually decay. Sunspots expand and contract as they move across the surface of the Sun, with diameters ranging from to . Larger sunspots can be visible from Earth without the aid of a telescope. They may travel at relative speeds, or proper motions, of a few hundred meters per second when they first emerge. Indicating intense magnetic activity, sunspots accompany other active region phenomena such as coronal loops, prominences, and reconnection events. Most solar flares and coronal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sun Gun
The sun gun or heliobeam is a theoretical orbital weapon, which makes use of a concave mirror mounted on a satellite, to concentrate sunlight onto a small area at the Earth's surface, destroying targets or killing through heat. History In 1929, the German physicist Hermann Oberth developed plans for a space station from which a 100-metre-wide concave mirror could be used to reflect sunlight onto a concentrated point on the earth. Later during World War II, a group of German scientists at the German Army Artillery proving grounds at Hillersleben began to expand on Oberth's idea of creating a superweapon that could utilize the sun's energy. This so-called "sun gun" (''Sonnengewehr'') would be part of a space station above Earth. The scientists calculated that a huge reflector, made of metallic sodium and with an area of , could produce enough focused heat to make an ocean boil or burn a city. After being questioned by officers of the United States, the Germans claimed that the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flower Pot
A flowerpot, planter, planterette or plant pot, is a container in which flowers and other plants are cultivated and displayed. Historically, and still to a significant extent today, they are made from plain terracotta with no ceramic glaze, with a round shape, tapering inwards. Flowerpots are now often also made from plastic, metal, wood, Rock (geology), stone, or sometimes biodegradable material. An example of biodegradable pots are ones made of heavy kraft paper, brown paper, cardboard, or sphagnum, peat moss in which young plants for transplanting are grown. For seedling starting in commercial greenhouses or polytunnels, pots usually take the form of trays with cells, each cell acting as one small pot. These trays are often called flats. There are usually holes in the bottom of pots, to allow excess water to flow out, sometimes to a saucer that is placed under the flowerpot. The plant can use this water with its roots, as needed. Recently, some flowerpots have been made wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rear Projection Screen
A video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. Video projectors use a very bright ultra-high-performance lamp (a special mercury arc lamp), Xenon arc lamp, LED or solid state blue, RB, RGB or remote fiber optic RGB lasers to provide the illumination required to project the image, and most modern ones can correct any curves, blurriness, and other inconsistencies through manual settings. If a blue laser is used, a phosphor wheel is used to turn blue light into white light, which is also the case with white LEDs. (White LEDs do not use lasers.) A wheel is used in order to prolong the lifespan of the phosphor, as it is degraded by the heat generated by the laser diode. Remote fiber optic RGB laser racks can be placed far away from the projector, and several racks can be housed in a single, central room. Each projector can use up to two racks, and several monochrome lasers are mounte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardware Store
Hardware stores (in a number of countries, "shops"), sometimes known as DIY stores, sell household hardware for home improvement including: fasteners, building materials, hand tools, power tools, keys, locks, hinges, chains, plumbing supplies, electrical supplies, cleaning products, housewares, tools, utensils, paint, and lawn and garden products directly to consumers for use at home or for business. Many hardware stores have specialty departments unique to its region or its owner's interests. These departments include hunting and fishing supplies, plants and nursery products, marine and boating supplies, pet food and supplies, farm and ranch supplies including animal feed, swimming pool chemicals, homebrewing supplies and canning supplies. The five largest hardware retailers in the world are The Home Depot, Lowe's (both in the United States), Kingfisher of the United Kingdom, Obi of Germany, and Leroy Merlin of France. United States Larger hardware stores may sell small ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refractor
A refracting telescope (also called a refractor) is a type of optical telescope that uses a lens as its objective to form an image (also referred to a dioptric telescope). The refracting telescope design was originally used in spyglasses and astronomical telescopes but is also used for long-focus camera lenses. Although large refracting telescopes were very popular in the second half of the 19th century, for most research purposes, the refracting telescope has been superseded by the reflecting telescope, which allows larger apertures. A refractor's magnification is calculated by dividing the focal length of the objective lens by that of the eyepiece. Refracting telescopes typically have a lens at the front, then a long tube, then an eyepiece or instrumentation at the rear, where the telescope view comes to focus. Originally, telescopes had an objective of one element, but a century later, two and even three element lenses were made. Refracting telescope is a technology t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Telescope Types
The following are lists of devices categorized as types of telescopes or devices associated with telescopes. They are broken into major classifications with many variations due to professional, amateur, and commercial sub-types. Telescopes can be classified by optical design or mechanical design/construction. Telescopes can also be classified by where they are placed, such as space telescopes. One major determining factor is type of light, or particle being observed including devices referred to as "telescopes" that do not form an image or use optics. Some telescopes are classified by the task they perform; for example Solar telescopes are all designs that look at the Sun, Dobsonian telescopes are designed to be low cost and portable, Aerial telescopes overcame the optical shortcomings of 17th-century objective lenses, etc. List of optical telescope types Optical telescopes can be classified by three primary optical designs (refractor, reflector, or catadioptric), by sub-design ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Footnotes
A note is a string of text placed at the bottom of a page in a book or document or at the end of a chapter, volume, or the whole text. The note can provide an author's comments on the main text or citations of a reference work in support of the text. Footnotes are notes at the foot of the page while endnotes are collected under a separate heading at the end of a chapter, volume, or entire work. Unlike footnotes, endnotes have the advantage of not affecting the layout of the main text, but may cause inconvenience to readers who have to move back and forth between the main text and the endnotes. In some editions of the Bible, notes are placed in a narrow column in the middle of each page between two columns of biblical text. Numbering and symbols In English, a footnote or endnote is normally flagged by a superscripted number immediately following that portion of the text the note references, each such footnote being numbered sequentially. Occasionally, a number between bracke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telescope Types
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. Originally meaning only an optical instrument using lenses, curved mirrors, or a combination of both to observe distant objects, the word ''telescope'' now refers to a wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors. The first known practical telescopes were refracting telescopes with glass lenses and were invented in the Netherlands at the beginning of the 17th century. They were used for both terrestrial applications and astronomy. The reflecting telescope, which uses mirrors to collect and focus light, was invented within a few decades of the first refracting telescope. In the 20th century, many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s. Etymology The word ''telescope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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