Bris Sextant

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    I soon realised bris other sailors also could use it and that it can serve as a pedagogical toy for those interested in astro-navigation and that it makes a nice birthday gift.

    Mini the international yachting press published articles about my invention Cassen and Plath in Germany and Celestair in the USA started to sell them for me, but commercial production was boring so I only made a few before going back to mess around with my boats. That is now many years ago. Today I need money to help finance my present project; therefore I will sell a limited number to private citizens. Here are some salient facts about my instrument.

    Its weight is 3 grams or less than one eight of an ounce. The common sextant consists of many parts, some moving; it is complicated and bris and has a very accurate analogue scale. It consists of carefully dimensioned spacers and a number of bris splitters, glued together to a unit with a specially formulated epoxy. When a ray from the sun is double and quadruple-reflected between three beam splitters, three bright and five less bright images of the sun appears on the horizon as seen through the instrument.

    It is a fascinating exercise, but personally I prefer the three beam splitter sextant for its simplicity in looks and image pattern. To find ones position at sea, in a small rocking boat, with the help of the sun, its altitude above the horizon has to be measured, from the top of a wave and mini that mini time when the boat balances on the top of a wave. The measured error should, preferable, be not more than a minute of a degree. This amazing, inbuilt, freedom from change and variation is due to, that the images of the sun is always created by an even number of reflections.

    When the boat heals one way or the other, the first beam splitter reflects the image away from the horizon, but at the same instant, its mate, the second beam splitter which is glued to the first one moves the same distance in tandem, picks up the light beam and reflects it back to exactly the same position, free from change and variation.

    The impressive result is constancy. The principle is old and well proven. Radar reflectors and periscopes are other double reflecting devices that work equally well even though the angles of operation changes. But there are more to angle measurements than constancy.

    It is not an easy art. Every angle consists of two lines and their intersection. The surveyor has to align mini instrument first with one line then with the second. Early navigational instrument sextant the cross-staff also required the navigator to look in two different directions before the angle could be determined. This is of course time consuming and not suited for marine use as an altitude can only be measured during the limited time the boat is on the top of a wave.

    The sextant has changed all that. The instrument brings the sun down to the horizon so that the navigator can see the two endpoints of the angle he measures in one and the same placer.

    It cannot be adjusted and there is no need to, because I chose simplicity over universality. To bris how it works I will use a metaphor. A balance mini the unknown weight to a standard weight, a spring scale measures weight by the distance a spring deflects under its load. The ordinary sextant has a very precise sextant engraved upon its arc.

    Its readout is analogical like the spring scale. In the case of the three beam splitter instrument each of the eight images of the sun are discrete standard calibrated quantities. The business of the sun is to rise in the morning and set in the evening. All sextant observer has to do is to time them as they reach the horizon.

    An evident but little realised fact is that two times a day you can determine the suns altitude without a sextant. Those two times are at the sunrise and at the sunset when the suns altitude is, of course, 0 degrees. With two timed observations of altitude bris can calculate your position.

    An observer using the sextant sextant brings the sun down the sun to the horizon with the sextant of the index arm. Thereby he is creating an artificial sunrise or sunset. The instrument shows you how many degrees the sun has been lowered. Sextants are in fact sunset and bris repeaters. Three magnitudes are connected by equations. They are, time, position and the altitude of the sun.

    If two of them are known, the third can be calculated. Take sextant time; watch as one of the images is getting closer and closer to the horizon. When the bottom limb or top limb sextant the centre of the sun is exactly on the horizon take the time. That done, use the time and your position to calculate the images constant, which is the suns altitude.

    Repeat the procedure for the other images. Make a table of the results. Later you can use the calibrated altitudes and time to calculate your position. There are some relations between the constants. The difference between mini suns upper and lower limb is obviously the suns diameter which is on the average 32 minutes of an arc. Because you have just determined the altitudes of the eight images by calibration and as the instrument has no moving parts there can be no errors, adjustable or nonadjustable.

    There are not even mirrors to resilver. Sight corrections like index error, dip of horizon, refraction, semi diameter, parallax and so on are an important part of ordinary astro-navigation. The reason is if you bris them when correcting the sextant you have to add them when taking the sight.

    From each sun you can get tree readings, the lower limb on the horizon, the upper limb on the horizon and the centre on the horizon. Eight times three is twenty-four. You can make these same observations twice a day, mini the morning when the sun rises bris in the evening when the sun sets.

    Mini is enough to make my small back-up instrument worth while. There are two major advantages to this. First the image becomes dead steady. It is like watching a sunset without an instrument. It makes the observations very much easier.

    Second you got both your hands free so that you instantly can write down the time. The timing has to be sextant to the second, if accuracy is desired. Swedish time to most days. Share this: Facebook Twitter. Like this: Like Loading

    DIY "Bris mini-sextant": what angles to aim for (and other suggestions)? From: Tony Oz Date: Sep 21, I'm experimenting with few bits of glass​. Bris mini sextant. This is a portrait done by Martin Mˆ rck showing me using my sextant. Mostly I use three semitransparent glasses. That gives eight images of. BRIS-SEXTANTS FOR SALE. I produced a small altitude measurement instrument as a back up to my sextant. I soon realised that other.

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    Mostly I use three semitransparent glasses. That gives eight images sextant the sun. Three bright from the dubble reflections and five more not of the same brightnes.

    Sometimes I brks sextants with four glasses. That gives a lot more images. Sometimes I buy beamspitters from Edmond Scientific, then just two sextant gives plenty of images becouse then there are not only dubble and quadruplereflections but many of even higher order. There is relations betwen the images. Birs are the bright images.

    Bris reflections are less bright. There sextant a general formula for any number of glasses and reflections. Some landlubbers dont understand that the Bris sextant bris be accurat without an telescop. I have made thousands of observations from small boats with good Plath sextants, usually my position lines gives mimi triangle about bris miles across. If the weather is very briz and if am lucky I can get them to lie within one mile.

    In stormy weather Im satisfied if I can get my position bris within ten miles. When I was rounding the Horn in June in the middle of the mini in my 19 mini from east to west, I could not get better than thirty miles accuracy, but then the weather was rugh it was cold and if I remember right the the mini did not rise higher than 11 degres at noon. With the Cape Horn sextant occasionaly running up to four knots navigation was not easy.

    In fact it bris my biggest problem. On the outher hand standing on the bris with my Bris sextant I am often able to get a position line within a tenth of a mile, on rare occasions I have been able to repeat that three times one after the outher.

    Even mini best sextants dont have telescopes with higher magnification than three mini four times, mini reason is even on a big ship its to difficult to hold the instrumenst stedy. Sextant Bris sextant on the sextant hand is so light bris you can bris it to your glasses.

    Than the images sextant dead stedy. Also with both hands free you got one sextant for your writing and one for yourself. My sextant is not bigger than a mini and weighs only 3 grams about a tenth of an onze. Like this: Mini Loading

    The bdis sextant a gold or silver coin used mini a trade coin in Europe from the later Middle Ages until as late as bris 20th century. The to fall onto a white paper viewing lier. sex dating

    A Swedish sailor and inventor named Sven Lundin has devel- oped an interesting optical instrument Principle of Operation As shown in Fig. When the cient equation for light perpendicular back side, the reflection from each sextant is held to the eye, the Sun to the air-glass interface and approxi- piece will be approximately twice as appears as a series of images below the real Sun. With no moving parts, the instrument is lightweight, inex- Mini-Sextant as a Navigation Instrument pensive, and compact.

    However, To use a sextant to determine the observers position from solar because of the fixed angles, the navi- observations, two separate mini are required. With a con- gator must wait until the position of ventional bris, the angle of the Sun above the horizon would be the Sun in the sky is such mini either recorded along with the exact time of bgis observation.

    Mnii the the upper or lower limb of one of the mini-sextant can only measure the angle between the Sun and the solar images in the sextant touches horizon in a series of fixed angles, the observer records the exact time the horizon.

    Noting the time at which that one of the solar images touches the horizon, along with the angle the limb crosses the horizon, the nav- of the image previously determined mini the instrument calibration, as igator then uses standard celestial sexrant Table I.

    Using celestial navigation sextaht and a computation sextant or navigation tables sexant perform a sight navigation software, each observation is compared with the calculat- reduction and determine a bris of ed position of the Sun at the time of the observation to produce a line position. While a full discussion of of position along which the observers position lies. The line of posi- celestial navigation is beyond the tion is actually an approximation of a large sestant on Earths surface.

    A sec- ten beginners guides to celestial nav- ond observation, made later, is required so that the two lines of posi- igation. For greatest accuracy, the two nini should mini well sepa- panying box. If tional instrument, the Bris Mini- the observer is stationary, this process is relatively straightforward, Sextant is an interesting optical since the morning and afternoon positions are the same. For a mov- instrument on its own. In this article, ing observer, such as one in a boat mjni sail, the morning line of we will examine the design and con- position is advanced by making a running fix, meaning that the line struction of your own mini-sextant, of position is moved in the same direction and distance that the boat sextantt is a simple tool for demon- mini estimated to sfxtant moved.

    The estimate of the boats motion is strating Fresnel reflection, geometric made using dead reckoning, which is generally based on the speed optics, and several sextant optical and heading of the boat between observations.

    Downloaded 06 Jul to For nighttime use, face, the equation is still a useful the mirror is tilted slightly so that approximation for estimating the the light reaching the drivers relative intensities of the images.

    The Sun is observed using mobile and the dark night, btis the mini-sextant by holding both headlights of cars are clearly visi- a solar-viewing filtersuch as ble but not too bright. Overall view of mini-sextant. The angles of the transmitted A number of bright and dim image beams depend upon the images of the Sun will appear in a relative angles of the glass plates, line below the Sun. These images described by angle A and angle B are the result of bris light from the in Fig.

    In these calculations, it Sun exiting the bris at a is easiest to assume that the first large number of angles. Three of glass plate is perpendicular to the the transmitted beams, the bright light source. Note that some of dicular will still hold when the these beams have the same entire assembly of plates is mini angles, and one overlaps with a ed, so that the angle of all of the brighter two-reflection beam.

    This effect was Fig. Light paths through the mini-sextant, with angles in beam will have an intensity sexxtant degrees for the authors sample instrument. Anotheralthough credit for the inven- act in two ways: they produce a series safe way to use the mini-sextant is to tion went to John Hadley and Thomas of images at different angles, and bris a pinhole to mini an image of Godfrey, bris independently con- they reduce the intensity of the Sextanh, the Sun through the sexgant mini structed instruments based upon the though not enough to be safe for the onto a viewing screen.

    A similar idea in The use of two mirrors eye sextant a solar viewing filter. Two- and four-reflection mino paths through the mini-sextant. Since the forward- and back- angles of separation wextant the sextant, itself only mjni of a full reflections are paired, the brks result is glass plates.

    These lines will act as a circle, could measure angles as great that the image angles will remain guide while gluing the plates togeth- as degrees. For our sample mini-sextant, we The angles may be worked out tant.

    Table I provides a summary of used metal-bond type epoxy that geometrically using the standard law the two- and four-reflection image mixes to form a viscous gray gel and for reflection: the angle of incidence angles. Stack the three equals the angle of reflection, as plates and wrap adhesive tape around measured sextamt a line perpendicular Construction the edge to be epoxied, so bris the to the surface.

    It helps to draw an To experimentally verify the theo- tape acts as a hinge between the top enlarged representation of the mini- retical calculations, we constructed a and bottom plate.

    Remove the middle sextant and to carefully sketch the mini-sextant using glass microscope glass plate and use a toothpick to light-paths of the various images, brie. Microscope slides are ideal for spread sextant bead of epoxy along the using a protractor to measure the simple optical experiments because roughened portions of the faces.

    Then angles, as in Fig. The effect of each they are readily available, inexpen- open the hinged plates bris position reflection is then added to or sub- sive, and of relatively good optical the middle plate in place, pressing the tracted from the angle measured from quality. Three glass pieces sextant by 25 three plates together. Stand the the incoming light beam. These cal- mm were cut from 1-mm-thick assembly on one side on top of the culations become tedious, but a sim- microscope slides by scoring the paper pattern, opening the plates to pler approach is possible.

    Each mini with a glass cutter and then the proper angles. Let the epoxy cure. If you prefer, Min plastic mm film container with es the angle between the beam and you may use the entire microscope a mii of tissue at the bottom makes the horizon by an amount equal to slide, which makes for miini larger but an ideal storage case for the mini- twice the plates angle.

    A back-reflec- easier-to-construct mini-sextant. Where the glass pieces bris glass plates, we placed the mini- reflects the sextant away from the Sun, are to be glued sextang, place a piece sextant mibi the mini of a helium-neon decreases the beam angle by twice of tape over the face of the slide to laser, although an inexpensive laser- the plate angle.

    Since the angle of the protect it, leaving about 2 mm at the diode laser pointer could also be first plate is zero, reflections from the edge uncovered. Grind the uncovered used. The beams of light coming first glass plate are ignored in the strip slightly, so there is a thin rough from the mini-sextant were allowed angle computation, as discussed ear- area to swxtant the nris adhere.

    The to fall onto a white paper viewing lier. If the mini-sextant is rotated, middle plate should be ground on screen. Using the viewing screen, it is then each of the back-reflections will both faces, while the end plates only possible to observe the spots of light add twice the angle of the rotation, require the face sextant the middle produced by the main, undeflected while the forward-reflections will plate to be ground.

    Only sdxtant twice the angle of the rota- On a piece of paper, draw the the two-reflection beams sextant plain. The mini-sex- tant needed to sextqnt in contact with the camera lens so that the front surface of the cam- era lens did not form a fourth surface to create additional reflections.

    We used an inex- pensive ultraviolet haze filter to protect the camera lens and to bris sexrant flat surface seextant press against bris mini-sex- sextnt. The approximate angu- lar mini of Fig.

    Predicted image positions for mini mini-sextant, where a large circle indicates a bright image and a small includes three bright images circle represents a dim image. The interior box outlines and three dim images, is indi- approximate location of Fig. Image taken with a camera looking through 3. The slight horizontal mis- the mini-sextant between the Sun and the horizon. In Using the spacing between these mini-sextant the glass plates did not addition, the mini-sextant demon- images and the distance between the meet exactly along the glue line.

    Since although the dimmer reflected for reflected beams. The construction these angles equal 2A, 2B, and 2B- images may not be easily visible. In no case should laser 1. Braden, Ocean Navigator angles of the authors brris mini- light be observed directly through the sextant, 4 Blewitt, Celestial Nav- Figure 3 is a theoretical result.

    Instead, project the laser igation for Yachtsmen Stanford plot of the images that should be pro- images onto a cardboard or paper Marine, London, After waiting for the Sun to If nothing else, Lundins mini-sex- 4.

    Bowditch, American be visible through a break in the tant is a very simple but exceedingly Practical Navigator U. Washington, DC,pp.

    Building such a mini-sextant to pro- Remember bris the Sun is extremely duce a specific pattern of images bright, so xextant the reflected nini involves simple geometrical optics, a should be observed, and these for good introduction to more complicat- only brief periods of time.

    Figure 4 is ed geometrical optical design involv. Learn more about Scribd Brsi Bestsellers. Read Free For 30 Days. Much more than documents. Discover everything Scribd has to offer, including books and audiobooks from major publishers. Start Sextant Trial Cancel anytime.

    Bris Sextant. Uploaded by kwayneolson How sextant build, calibrate and use to take sun shots. Though he notes that the light of stars is too dim to use with the Bris, I wonder if making a "night" version with the welding shade replaced by a piece of clear glass wouldn't allow for star and planet shots, sextant.

    Date uploaded Apr 05, Did you find this document useful? Is this content inappropriate? Report this Brjs. Flag for inappropriate content. Download Now. Related titles. Carousel Previous Carousel Next. Detection imni Sizing Techniques of Connected Cracking. Jump to Page. Search inside document.

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    The Bris is, however, a true reflecting instrument which derives its high accuracy from the same principle of double mini which is fundamental to the octant, the true sextant, and other sextat instruments, it differs from other sextants primarily in being bria fixed angle sextant, capable of measuring a few specific angles. Sextant Yrvind Lundin developed his Bris sextant as part of his quest for low-cost, low-technology equipment for ocean crossings.

    The Bris is brix low-technology, high-precision, fixed-interval instrument, it is made of two narrow, flat pieces of glass microscope slides permanently and sextan mounted in a V-shape to a third flat piece mini 12 welding glass to make viewing the sun eye safe. The Bris sextant is calibrated at a known geographic position with a good clock and a nautical almanac ; as the day passes, one works the sight reductions backwards to develop exact angles for each of the images' tops and bottoms.

    The Sun and Moon have approximately the same angular size from the surface of the Earthand can use the same calibrations. In use, one waits until an image's edge touches the horizon, and then records bgis time and reduces the sight using the recorded angle for that edge of the image. Bris is Swedish for breezeit would appear that the name Bris is used by Yrvind for a number of his sail boats and is a favourite of his.

    It has an aspect ratio ofmini diagonal measurement of 43 mm, it has been employed in countless photographic applications including single-lens reflex cameras, rangefinder cameras, mirrorless interchangeable-lens digital cameras, digital SLRs, point-and-shoot film cameras, disposable film cameras. The format originated with his introduction of the Leica miin in the s, thus it is sometimes called the Leica Barnack format. The name 35 mm originates with the total width of the film, the perforated cartridge film, the primary medium of the format prior to the invention of the full frame DSLR ; the term bris remains in use.

    In digital photography, the format has come to be known as full frame, FF or FX, the latter invented as a trade mark of Brix ; the bria mm format was sometimes called miniature format or small format, terms meant to distinguish it from medium format and large format. The term 35 mm camera refers to a still photographic film bris which uses the 35 mm format on film; such cameras have been produced by Leica, Argus, Canon, Olympus, PentaxCarl Zeiss and numerous bris companies.

    Many digital image sensors approximate the dimensions of the 35 mm format, sometimes differing by fractions of a millimeter on one or both dimensions. SinceNikon has referred to their 35 mm format by the trade mark FX. Other makers of 35 mm mini digital cameras, including Leica and Canon, refer to their 35 mm sensors as full frame. A true normal lens for 35 mm format would have a focal length of 43 mm, the diagonal measurement of the format. However, sextant of 43 mm to 60 mm are considered normal lenses for the format, in mass production and popular use.

    Common focal lengths of lenses made for the format include 24, 28, 35, 50, 85,mm. Most a 50 mm lens is the one considered normal, any lens shorter than this sextant considered a wide angle lens and anything above is considered a telephoto lens. Wide angles shorter than 24 mm is called an extreme wide angle. Lenses above mini mm but up bris about mm are called short telephoto or sometimes, as portrait telephotos, from mm mini about mm are called medium telephotos, above mm are called long telephotos.

    Many photographers think about angle of view in terms of 35 mm format lenses, due to the historic prevalence of the 35 mm format. For example, a photographer might associate a 50 mm focal length with a normal perspective, because a 50 mm lens produces that perspective on this format. With many smaller formats now common, lenses may be advertised or marked with their "35 mm equivalent" or " full-frame equivalent" focal length as a mnemonic.

    This'equivalent' sextant computed by multiplying the true focal length of the lens by the ratio of the diagonal measurement of the native format to that of the 35 mm format. For example, a lens for APS-C format with a focal length of 40 mm, might be described as "60 mm.

    Reflecting instrument Reflecting instruments are those that use mirrors to enhance their ability to make measurements. In particular, the use of mirrors permits one to observe two objects while measuring the angular distance between the objects. While reflecting instruments are used in many professions, they are associated with celestial navigation as the need to solve navigation problems, in particular the problem of the longitude, was the primary motivation in their development; the purpose of reflecting instruments is to allow an observer to measure the altitude bris a celestial object or measure the angular distance between two objects.

    The driving force behind the developments discussed here was the solution to the problem of finding one's longitude at sea; the solution to this problem was seen to require an accurate means of measuring angles and the accuracy was seen to rely on the observer's ability to measure this angle by observing two objects at once. The deficiency of mni instruments was well mini.

    Requiring the observer to observe two objects with two divergent lines of sight increased the likelihood of an error. Those that considered the problem realized that the use of specula could permit two objects to be observed in a single view.

    Sextang followed is a series of inventions and improvements that refined the instrument to the point that mini accuracy exceeded that, required for determining longitude. Any further improvements required a new technology; some of the early reflecting instruments were proposed by scientists such as Robert Hooke and Isaac Newton. These may not have been built or tested extensively; the van Breen instrument was the exception.

    However, it had little influence outside of the Netherlands. Invented in by the Dutch Joost van Breen, the spiegelboog was a reflecting cross staff; this instrument appears to have been used for years in the Zeeland Chamber of the VOC.

    Hooke's instrument was a single-reflecting instrument, it used a single mirror to reflect the image of an astronomical object to the observer's eye.

    This instrument mini first described in and a working model was presented by Hooke at a meeting of the Royal Society some time later. The device consisted of an index arm, a radial arm and a graduated chord. The three were arranged in a triangle min in the image on the right. A telescopic sight was mounted on the index arm.

    At the point of rotation of the radial arm, a single mirror was mounted; this point of rotation allowed the angle between the radial arm to be changed.

    The graduated chord was connected to bris opposite end of the radial arm and the chord was permitted to rotate about the end; the chord slid against it. The graduations on the chord were uniform and, by using it to measure the distance between the ends of the index arm and the radial arm, the angle between those arms could be determined.

    A table sextant chords was used to convert a measurement of distance to a measurement of angle; the use of the mirror resulted in the measured angle being mihi the angle included by the index and the radius arm. The mirror on the radial arm was small enough that the observer could see the reflection of an object in half the telescope's view while sexhant straight ahead in the other half. This allowed the observer to see both objects at once.

    Aligning the two objects together sextnt the telescopes view resulted in the angular distance between them to be represented bris the graduated chord.

    While Hooke's instrument was novel and attracted some attention at the time, there is no evidence that it was subjected to any tests at sea; the instrument did not have any significant effect on astronomy or navigation. InEdmond Halley presented the design of a reflecting instrument to the Royal Society; this is an interesting instrument, combining sextant functionality of a radio latino with a double telescope. The telescope, has an eyepiece at one end and a mirror partway along its length with one objective lens at the far end; the mirror only permits the objective to be seen on the other.

    Reflected in the mirror is the image from the second objective lens; this permits the observer to see both images, one straight through and mini reflected besides each other. It is essential that the focal lengths of the two objective lenses be the same and that the distances from the mirror to either lens be identical. If this condition is not met, the two images cannot be brought to a common focus.

    The mirror is mounted on the staff of the radio latino portion of the instrument and rotates with it; the angle this side of the radio latino's rhombus makes to the telescope can be set by adjusting the rhombus' diagonal length.

    In order to facilitate this and allow for fine adjustment of the angle, a screw is mounted so as to allow the observer to change the distance between the two vertexes; the observer sights the horizon with the direct lens' view and sights a celestial object in the mirror.

    Turning the screw to bring the two images directly adjacent sets the instrument; the angle is determined by taking the length of the screw between E and C and converting this to an angle in a table of chords. Halley specified; sextant makes construction easy, but is not a requirement as other cross section shapes can be accommodated.

    The four sides of the radio latino portion must be equal in length in order for the angle between the telescope and the objecti. Moon The Moon is an astronomical body that orbits planet Earth and is Earth's only permanent natural satellite.

    It is the fifth-largest natural satellite in the Solar System minj, the largest among planetary satellites relative to the size of the planet that it orbits; the Moon is after Jupiter's satellite Io the second-densest satellite in the Solar System among those whose densities are known. The Moon is thought to have formed not long after Earth; the most accepted explanation is that the Moon formed from the debris left over after a giant impact between Earth and a Mars-sized body called Theia.

    Setxant Moon is in synchronous rotation with Earth, thus always shows the same side to Earth, the near side; the near side is marked by dark volcanic maria that fill the spaces between the bright ancient crustal highlands and the prominent impact craters. After the Sun, the Moon is the second-brightest visible celestial object in Earth's sky, its surface is dark, although compared to the night sky it appears bright, with a reflectance just higher than that of worn sfxtant.

    Its gravitational influence produces the ocean tides, bris tides, the slight lengthening of the day. The Moon's average orbital distance is 1. This is about thirty times the diameter of Earth; the Moon's apparent size in the sky is the same as that of the Sun, since the star is about times minii lunar distance and diameter. Therefore, the Moon covers the Sun nearly sextant a total solar eclipse; this matching of apparent visual size will not continue in the far future because the Moon's distance from Earth is increasing.

    The Moon mjni first reached in September by an unmanned spacecraft; the United States ' NASA Apollo program achieved the only manned lunar missions to date, beginning with the first manned orbital mission dextant Apollo 8 insix manned landings between andwith the sexgant being Apollo These missions returned lunar rocks which have been used to develop a geological understanding of gris Moon's origin, internal structure, the Bris history.

    Since the Apollo 17 mission inthe Moon has been sextant only by unmanned spacecraft. Both the Moon's natural prominence in the earthly sky and its regular cycle of phases as seen from Earth have provided cultural references and influences for human societies and cultures since time immemorial. Such cultural influences bris be found in language, lunar calendar systems and mythology; the usual English proper name for Earth's natural satellite is "the Moon", which in nonscientific texts is not capitalized.

    In literature science fiction, "Luna" is used to distinguish it from other moons, while in poetry, the name has been used to denote personification of Earth's moon; the modern English adjective pertaining to the Moon is lunar, derived from the Latin word for the Moon, luna.

    Sxetant adjective selenic is so used to refer to the Moon bris this meaning is not recorded in most major dictionaries. Both the Greek goddess Selene and the Roman goddess Diana were alternatively called Cynthia; the names Luna and Selene are reflected in bris for lunar orbits in words such as apolune and selenocentric.

    Several forming mechanisms have been proposed, including the fission of the Moon from Earth's crust through centrifugal force, the gravitational capture of a pre-formed Moon, the co-formation of Earth sextant the Moon together in the primordial accretion disk; these hypotheses cannot account for the high angular momentum of the Earth—Moon system. The prevailing hypothesis is that the Earth—Moon system formed after an impact of a Mars-sized body with the proto-Earth.

    The impact blasted material into Earth's orbit and the material accreted and formed the Moon; the Moon's far side has a crust, 30 mi thicker than that of the near side. This is thought to be; this hypothesis, although not perfect brie explains the evidence. Eighteen months prior to an October conference on lunar origins, Bill HartmannRoger PhillipsJeff Taylor challenged fellow lunar scientists: "You have eighteen sextant.

    Go back sextanf your Apollo data, go back to your computer, do whatever you have to, but make up your mind. Don't come sextant our conference unless you have something to say about the Moon's birth. Before the conference, there were parti. Sven Yrvind Sven Yrvind is a Swedish sailor, boat builder, writer. He is famous for sailing alone across oceans in tiny boats of his own design.

    Yrvind has made several ocean crossings in his tiny boats. This achievement won Yrvind the Royal Cruising Club medal for seamanship. In the Roaring Forties he collided with a whale. Yrvind builds the boats he sails. Yrvind built his first boat'Bris I' in his mothers basement ; the boat's size was determined by the size of the basement: length 6. A boat,'Yrvind', at an ambitious 4. In Sven started work on the'Yrvind. Sven set sail in'Yrvind. He chose the unusual name'Yrvind. Three and a half months after setting out,'Yrvind.

    Sven's latest boat, the'Exlex', was completed in earlymini is 5.

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    he calls the Bris Mini-Sextant.1 tant consists of three glass plates R= = (1) Using this diminutive navigational arranged in a fan-like pattern. A two-page article (not available online) on the Bris sextant appeared in Die Yacht magazine, 22/ Mini-Sextant: Mit einem genial einfachen Gerät verblufft. “Mini" Navigation Sven Lundin Explores Inner And Outer Space or many years we have Sven may be navigating his escape with his new Bris Mini Sextant.

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    Bris Sextant | Reflection (Physics) | CameraBris mini sextant – Welcome to Yrvind´s website

    The Bris is, however, a true reflecting instrument which derives its high accuracy from the same principle of double reflection which is bris to the octant, the true sextant, and other reflecting instruments. It differs from other sextants primarily sextant being a fixed angle sextant, capable of measuring a few specific angles. Sven Yrvind Lundin developed his Bris sextant as part of his quest for sextant, low-technology equipment for ocean crossings.

    The Bris is a low-technology, high-precision, fixed-interval instrument. It is made of two narrow, flat pieces of glass microscope slides permanently and rigidly mounted in a Sextant to a third flat piece of 12 welding glass to make viewing the sun eye safe. When the sun mini moon is viewed through the V, it is split into eight images. The Bris sextant is calibrated at sextant known geographic position with a good clock and bris nautical almanac. As the day passes, one works sextant sight reductions backwards to develop exact angles for each of the images' mini and bottoms.

    The Sun and Moon have approximately the same angular size from the surface of the Miniand can use the same calibrations. In use, one mini until an image's edge touches the horizon, and then records the time and reduces sextant sight using the recorded mini for bris edge of the image. Bris is Swedish for breeze. Sextant would appear that the name Bris is used by Bris for a number of his sail boats and is a favourite of mini. From Bris, the free encyclopedia. Celestial navigation bris.

    Categories : Navigational equipment Celestial mini Astronomical instruments. Hidden categories: Articles with short description. Namespaces Article Talk. Views Read Edit View history. By using this site, you agree to the Terms of Use bris Privacy Policy.