Astronomical instruments used in geography. The oldest astronomical instruments

Celestial bodies have interested people since time immemorial. Even before the revolutionary discoveries of Galileo and Copernicus, astronomers made repeated attempts to find out the patterns and laws of motion of planets and stars and used special tools for this.
The tools of ancient astronomers were so complex that it took modern scientists years to figure out how to use them.

1. Calendar from Warren Field
Although strange indentations at Warren Field were discovered from the air as early as 1976, it was not until 2004 that it was determined that this was an ancient moon calendar. According to scientists, the found calendar is about 10,000 years old.
It looks like 12 recesses arranged in an arc of 54 meters. Each hole is synchronized with the lunar month in the calendar, and adjusted for the lunar phase.
It is also surprising that the calendar at Warren Field, which was built 6000 years before Stonehenge, is oriented to the point of sunrise on the winter solstice.

2. Sextant Al-Khujandi in painting
There is very little information about Abu Mahmud Hamid ibn al-Khidr al-Khujandi, except that he was a mathematician and astronomer who lived on the territory of modern Afghanistan, Turkmenistan and Uzbekistan. He is also known to have created one of the largest astronomical instruments in the 9th and 10th centuries.
His sextant was made in the form of a fresco located on a 60-degree arc between two interior walls building. This huge 43-meter arc was divided into degrees. Moreover, each degree was divided into 360 parts with jewelry accuracy, which made the fresco a stunningly accurate solar calendar.
Above the arc of Al-Khujandi there was a domed ceiling with a hole in the middle, through which the sun's rays fell on the ancient sextant.

3. Volvelles and the Zodiac Man
In Europe at the turn of the 14th century, scientists and doctors used a rather strange variety of astronomical instruments - volvella. They looked like several round sheets of parchment with a hole in the center, stacked on top of each other.
This made it possible to move the circles to calculate all the necessary data - from the phases of the moon to the position of the sun in the zodiac. The archaic gadget, in addition to its main function, was also a status symbol - only the richest people could acquire a volvella.
Medieval doctors also believed that each part of the human body was controlled by its own constellation. For example, Aries was responsible for the head, and Scorpio was responsible for the genitals. Therefore, for diagnosis, doctors used volwells to calculate the current position of the moon and sun.
Unfortunately, the volvels were quite fragile, so very few of these ancient astronomical instruments have survived.

4 Ancient Sundial
Today, the sundial serves only to decorate garden lawns. But they were once necessary to keep track of time and the movement of the Sun across the sky. One of the oldest sundials was found in the Valley of the Kings in Egypt.
They date back to 1550 - 1070 BC. and represent a round piece of limestone with a semicircle drawn on it (divided into 12 sectors) and a hole in the middle into which a rod was inserted that cast a shadow.
Shortly after the discovery of the Egyptian sundial, similar ones were found in Ukraine. They were buried with a man who died 3200 - 3300 years ago. Thanks to Ukrainian watches, scientists learned that the Zrubn civilization had knowledge of geometry and was able to calculate latitude and longitude.

5. Sky disk from Nebra
Named for the German city where it was discovered in 1999, the "sky disk from Nebra" is the oldest depiction of the cosmos ever found by man. The disc was buried next to a chisel, two axes, two swords, and two mail bracers about 3,600 years ago.
The bronze disk, covered with a layer of patina, had gold inserts depicting the Sun, Moon and stars from the constellations Orion, Andromeda and Cassiopeia. No one knows who made the disk, but the arrangement of the stars suggests that the creators were located at the same latitude as Nebra.

6. Chanquillo Astronomical Complex
The ancient Chanquillo Astronomical Observatory in Peru is so complex that its true purpose was only discovered in 2007 using a computer program designed to align solar panels.
The 13 towers of the complex are built in a straight line 300 meters long along the hill. Initially, scientists thought that Chanquillo was a fortification, but for a fort it was an incredibly bad place, since it had neither defensive advantages nor running water, no food sources.
But then archaeologists realized that one of the towers looks at the sunrise point at the summer solstice, and the other at the sunrise point at the winter solstice. Built about 2,300 years ago, the towers are the oldest solar observatory in America. According to this ancient calendar, it is still possible to determine the day of the year with a maximum of two days of error.
Unfortunately, the huge solar calendar from Chanquillo is the only trace of the civilization of the builders of this complex, who predated the Incas by more than 1000 years.

7. Hyginus Star Atlas
The Hyginus Star Atlas, also known as the Poetica Astronomica, was one of the first works to depict the constellations. Although the authorship of the atlas is disputed, it is sometimes attributed to Gaius Julius Hyginus (Roman writer, 64 BC - 17 AD). Others argue that the work bears similarities to those of Ptolemy.
In any case, when the Poetica Astronomica was republished in 1482, it was the first printed work to show the constellations as well as the myths associated with them.
While other atlases provided more specific mathematical information that could be used for navigation, the Poetica Astronomica was a more whimsical, literary interpretation of the stars and their history.

8. Celestial globe
The celestial globe appeared even when astronomers believed that the stars move around the Earth in the sky. Celestial globes that were created to represent this celestial sphere began to be created by the ancient Greeks, and the first globe in a shape similar to modern globes was created by the German scientist Johannes Schöner.
At the moment, only two of Schöner's celestial globes have survived, which are real works of art depicting constellations in the night sky. The oldest surviving example of a celestial globe dates from around 370 BC.

9. Armillary sphere
The armillary sphere - an astronomical instrument in which several rings surround a central point - was a distant relative of the celestial globe.
There were two different types of spheres - observation and demonstration. The first of the scientists who used such spheres was Ptolemy.
With this tool, it was possible to determine the equatorial or ecliptic coordinates of celestial bodies. Along with the astrolabe, the armillary sphere has been used by sailors for navigation for many centuries.

10. El Caracol, Chichen Itza
The El Caracol Observatory at Chichen Itza was built between 415 and 455 AD. The observatory was very unusual - while most astronomical instruments were tuned to observe the movement of stars or the Sun, El Caracol (translated as "snail") was built to observe the movement of Venus.
For the Maya, Venus was sacred - literally everything in their religion was based on the cult of this planet. El Caracol, in addition to being an observatory, was also the temple of the god Quetzalcoatl.

Astrolabe.

Mirror telescope (reflector) by I. Newton.

Telescope I. Kepler.

Giant telescope J. Hevelius.

Quadrant for determining the heights of heavenly bodies.

40-foot reflecting telescope by V. Herschel.

Reflecting telescope with a mirror diameter of 2.6 m of the Crimean Astrophysical Observatory.

The entire history of astronomy is connected with the creation of new instruments that make it possible to increase the accuracy of observations, the ability to conduct research on celestial bodies in the ranges of electromagnetic radiation (see Electromagnetic radiation of celestial bodies) that are inaccessible to the naked human eye.

Goniometric instruments were the first to appear in ancient times. The oldest of them is the gnomon, a vertical rod that casts the sun's shadow onto a horizontal plane. Knowing the length of the gnomon and the shadow, one can determine the height of the Sun above the horizon.

Quadrants also belong to the old goniometric instruments. In its simplest form, a quadrant is a flat board shaped like a quarter of a circle divided into degrees. A movable ruler with two diopters rotates around its center.

Widespread in ancient astronomy were armillary spheres - models of the celestial sphere with its key points and circles: the poles and the axis of the world, the meridian, the horizon, the celestial equator and the ecliptic. At the end of the XVI century. the best astronomical instruments in terms of accuracy and elegance were made by the Danish astronomer T. Brahe. His armillary spheres were adapted to measure both the horizontal and equatorial coordinates of the luminaries.

A radical change in the methods of astronomical observations occurred in 1609, when the Italian scientist G. Galileo used a telescope to view the sky and made the first telescopic observations. In improving the designs of refracting telescopes with lens objectives, great merit belongs to I. Kepler.

The first telescopes were still extremely imperfect, they gave a fuzzy image, colored with an iridescent halo.

They tried to get rid of the shortcomings by increasing the length of the telescopes. However, the most efficient and convenient were achromatic refracting telescopes, which began to be manufactured in 1758 by D. Dollond in England.

For photographic observations, astrographs are used.

Astrophysical research requires telescopes with special devices designed for spectral (objective prism, astrospectrograph), photometric (astrophotometer), polarimetric and other observations.

Instruments have been created that make it possible to observe celestial bodies in various ranges of electromagnetic radiation, including the invisible range. These are radio telescopes and radio interferometers, as well as instruments used in x-ray astronomy, gamma-ray astronomy, and infrared astronomy.

For the observation of some astronomical objects, special designs of instruments have been developed. These are the solar telescope, the coronograph (for observations of the solar corona), the comet detector, the meteor patrol, the satellite photographic camera (for photographic observations of satellites), and many others.

An important instrument needed for observations is the astronomical clock.

When processing the results of astronomical observations, supercomputers are used.

Significantly enriched our understanding of the Universe radio astronomy, which originated in the early 30s. our century. In 1943, Soviet scientists L. I. Mandelstam and N. D. Papaleksi theoretically substantiated the possibility of radar of the Moon. Radio waves sent by man reached the moon and, reflected from it, returned to earth. 50s 20th century - a period of unusually rapid development of radio astronomy. Every year, radio waves brought from space new amazing information about the nature of celestial bodies.

Today, radio astronomy uses the most sensitive receivers and the largest antennas. Radio telescopes have penetrated into such depths of space that so far remain inaccessible to conventional optical telescopes. The radio cosmos opened up before man - a picture of the Universe in radio waves.

Astronomical instruments for observations are installed at astronomical observatories. For the construction of observatories, places are chosen with a good astronomical climate, where the number of nights with a clear sky is sufficiently large, where atmospheric conditions are favorable for obtaining good images of celestial bodies in telescopes.

The Earth's atmosphere creates significant interference in astronomical observations. The constant movement of air masses blurs and spoils the image of celestial bodies, so in terrestrial conditions it is necessary to use telescopes with limited magnification (as a rule, no more than several hundred times). Due to the absorption of ultraviolet and most infrared wavelengths by the earth's atmosphere, a huge amount of information about the objects that are sources of these radiations is lost.

In the mountains, the air is cleaner, calmer, and therefore the conditions for studying the Universe are more favorable there. For this reason, since the end of the XIX century. all major astronomical observatories were built on mountain tops or high plateaus. In 1870, the French researcher P. Jansen used a balloon to observe the Sun. Such observations are carried out in our time. In 1946, a group of American scientists installed a spectrograph on a rocket and sent it into the upper atmosphere to a height of about 200 km. The next step in transatmospheric observations was the creation of orbital astronomical observatories (OAO) on artificial earth satellites. Such observatories, in particular, were the Soviet Salyut orbital stations. The Hubble Space Telescope is currently in operation.

Orbital astronomical observatories different types and appointments are firmly established in practice contemporary research outer space.

Try to imagine yourself as an ancient observer of the universe, completely devoid of any tools. How much can be seen in the sky in this case?

During the day, the movement of the Sun will attract attention, its rising, rising to its maximum height and slow descent to the horizon. If such observations are repeated from day to day, one can easily notice that the points of sunrise and sunset, as well as the highest angular height of the Sun above the horizon, are continuously changing. With long-term observations in all these changes, one can notice the annual cycle - the basis of the calendar chronology.

At night, the sky is much richer in both objects and events. The eye can easily distinguish the patterns of the constellations, the unequal brightness and color of the stars, the gradual change in the appearance of the starry sky during the year. The Moon will attract particular attention with its variability in external shape, grayish permanent spots on the surface and very complex movement against the background of stars. Less noticeable, but undoubtedly attractive, are the planets - these wandering non-flickering bright "stars", sometimes describing mysterious loops against the background of stars.

The calm, habitual picture of the night sky can be disturbed by the flash of a “new” bright unfamiliar star, the appearance of a tailed comet or a bright fireball, or, finally, by a “starfall”. All these events undoubtedly aroused the interest of ancient observers, but they had not the slightest idea of their real causes. At first, it was necessary to decide more a simple task- notice the cyclicity in celestial phenomena and create the first calendars based on these celestial cycles.

Apparently, the Egyptian priests were the first to do this, when, about 6,000 years before our days, they noticed that the early morning appearance of Sirius in the rays of dawn coincides with the flood of the Nile. For this, no astronomical instruments were needed - only great observation was required. But the error in estimating the length of the year was also great - the first Egyptian solar calendar contained 360 days in a year.

Rice. 1. The simplest gnomon.

The needs of practice forced the ancient astronomers to improve the calendar, to specify the length of the year. It was also necessary to understand the complex movement of the Moon - without this, the calculation of time on the Moon would be impossible. It was necessary to clarify the features of the motion of the planets and compile the first star catalogs. All of the above tasks involve angle measurements in the sky, the numerical characteristics of what has hitherto been described only in words. So there was a need for goniometric astronomical instruments.

The oldest of them gnomon (Fig. 1). In its simplest form, it is a vertical rod that casts a shadow on a horizontal plane. Knowing the length of the gnomon L and measuring the length I the shadow it casts, you can find the angular height h Suns above the horizon according to the modern formula:

The ancients used gnomons to measure the midday height of the Sun on various days of the year, and most importantly on the days of the solstices, when this height reaches extreme values. Let the midday altitude of the Sun on the summer solstice be H, and on the winter solstice h. Then the corner? between the celestial equator and the ecliptic is

and the inclination of the plane of the celestial equator to the horizon, equal to 90 ° -?, where? - latitude of the place of observation, calculated by the formula

On the other hand, by carefully watching the length of the midday shadow, you can quite accurately notice when it becomes the longest or shortest, that is, in other words, fix the days of the solstices, and hence the length of the year. From here it is easy to calculate the dates of the solstices.

Thus, despite its simplicity, the gnomon allows you to measure quantities that are very important in astronomy. These measurements will be the more accurate, the larger the gnomon and, consequently, the longer (ceteris paribus) the shadow cast by it. Since the end of the shadow cast by the gnomon is not sharply defined (because of the penumbra), on some ancient gnomons a vertical plate with a small round hole. The sun's rays, passing through this hole, created a clear sun glare on a horizontal plane, from which the distance to the base of the gnomon was measured.

As early as a thousand years BC, a gnomon was built in Egypt in the form of an obelisk 117 Roman feet high. In the reign of Emperor Augustus, the gnomon was transported to Rome, installed on the Field of Mars and determined with its help the moment of noon. At the Beijing Observatory in the 13th century A.D. e. a gnomon with a height of 13 was installed m, and the famous Uzbek astronomer Ulugbek (XV century) used a gnomon, according to some sources, 55 m. The tallest gnomon worked in the 15th century on the dome of the Florence Cathedral. Together with the cathedral building, its height reached 90 m.

The astronomical staff also belongs to the oldest goniometric instruments (Fig. 2).

Rice. 2. Astronomical staff (top left) and triquetra (right). At the bottom left is a drawing explaining the principle of operation of an astronomical staff.

Along the graduated ruler AB moving rail moved CD, at the ends of which small rods were sometimes strengthened - sights. In some cases, the sight with a hole was at the other end of the ruler AB, to which the observer put his eye (point A). By the position of the movable rail relative to the observer's eye, one could judge the height of the luminary above the horizon, or the angle between the directions of two stars.

The ancient Greek astronomers used the so-called triquetrome, consisting of three rulers connected together (Fig. 2). To a vertical fixed ruler AB rulers attached to hinges Sun and AS. On the first of them two viewfinders or a diopter are fixed. m and P. The observer guides the ruler Sun on the star so that the star is simultaneously visible through both diopters. Then, holding the ruler Sun in this position, a ruler is applied to it AC so that the distance VA and Sun were equal to each other. This was easy to do, since all three rulers that made up the triquetra had divisions of the same scale. By measuring the length of the chord on this scale AU, the observer then, using special tables, found the angle abc, that is, the zenith distance of the star.

Rice. 3. Ancient quadrant.

Both the astronomical staff and the triquetra could not provide high accuracy of measurements, and therefore they were often preferred quadrants- goniometric instruments that reached a high degree of perfection by the end of the Middle Ages. In the simplest version (Fig. 3), the quadrant is a flat board in the form of a quarter of a graduated circle. A movable ruler with two diopters rotates around the center from this circle (sometimes the ruler was replaced by a tube). If the plane of the quadrant is vertical, then it is easy to measure the height of the star above the horizon by the position of the pipe or sight line directed at the luminary. In cases where a sixth of a circle was used instead of a quarter, the instrument was called sextant and if the eighth part - octant. As in other cases, the larger the quadrant or sextant, the more accurate its graduation and installation in the vertical plane, the more accurate measurements could be made with it. To ensure stability and strength, large quadrants were strengthened on vertical walls. Such wall quadrants were considered the best goniometric instruments back in the 18th century.

The same type of instrument as the quadrant is astrolabe or an astronomical ring (Fig. 4). A metal circle divided into degrees is suspended from some support by a ring. A. In the center of the astrolabe there is an alidade - a rotating ruler with two diopters. By the position of the alidade directed at the luminary, its angular height is easily calculated.

Rice. 4. Ancient (right) and homemade astrolabe.

Often, ancient astronomers had to measure not the heights of the luminaries, but the angles between the directions to two luminaries, for example, to a planet and one of the stars). For this purpose, the universal quadrant was very convenient (Fig. 5a). This instrument was equipped with two tubes - diopters, of which one ( AC) fixedly fastened to the arc of the quadrant, and the second (Sun) revolved around its center. The main feature of the universal quadrant is its tripod, with which the quadrant could be fixed in any position. When measuring the angular distance from a star to a planet, the fixed diopter was directed to the star, and the movable diopter was directed to the planet. Reading on the quadrant scale gave the desired angle.

Widespread in ancient astronomy armillary spheres, or armillos (Fig. 56). In essence, these were models of the celestial sphere with its most important points and circles - the poles and the axis of the world, the meridian, the horizon, the celestial equator and the ecliptic. Often armillas were supplemented with small circles - celestial parallels and other details. Almost all circles were graduated and the sphere itself could rotate around the axis of the world. In a number of cases, the meridian was also made mobile - the inclination of the axis of the world could be changed in accordance with the geographical latitude of the place.

Rice. 5a. Universal quadrant.

Of all the ancient astronomical instruments, the armilla proved to be the most enduring. These models of the celestial sphere are still available in visual aid stores and are used in astronomy classes for a variety of purposes. Small armillas were also used by ancient astronomers. As for the large armillas, they were adapted for angular measurements in the sky.

Armilla was first of all rigidly oriented so that her horizon lay in the horizontal plane, and the meridian in the plane of the celestial meridian. When observing with the armillary sphere, the observer's eye was aligned with its center. A movable circle of declination with diopters was fixed on the axis of the world, and at those moments when a star was visible through these diopters, the coordinates of the star were counted from the divisions of the armilla circles - its hourly angle and declination. With some additional devices, with the help of armills, it was possible to measure directly the right ascensions of stars.

Rice. 56. Armillary sphere.

Every modern observatory has an accurate clock. There were clocks on ancient observatories, but they were very different from modern ones in terms of the principle of operation and accuracy. The most ancient of hours - solar. They have been used since many centuries before our era.

The simplest sundials are equatorial (Fig. 6, a). They consist of a rod directed to the North Star (more precisely, to the north pole of the world), and a dial perpendicular to it, divided into hours and minutes. The shadow from the rod plays the role of an arrow, and the scale on the dial is uniform, that is, all hour (and, of course, minute) divisions are equal to each other. The equatorial sundials have a significant drawback - they show time only in the period from March 21 to September 23, that is, when the Sun is above the celestial equator. You can, of course, make a double-sided dial and strengthen another lower rod, but this will hardly make the equatorial clock more convenient.

Rice. 6. Equatorial (left) and horizontal sundial.

Horizontal sundials are more common (Fig. 6, 6). The role of the rod in them is usually performed by a triangular plate, the upper side of which is directed to the north celestial pole. The shadow from this plate falls on a horizontal dial, the hour divisions of which this time are not equal to each other (only pairwise hour divisions are equal, symmetrical with respect to the noon line). For each latitude, the digitization of the dial of such watches is different. Sometimes, instead of a horizontal one, a vertical dial (wall sundial) or dials of a special complex shape were used.

The largest sundial was built in early XVIII century in Delhi. The shadow of a triangular wall whose vertex is 18 high m, falls on digitized marble arcs with a radius of about 6 m. These watches are still working properly and show the time with an accuracy of one minute.

All sundials have a very big drawback - in cloudy weather and at night they do not work. Therefore, along with the sundial, ancient astronomers also used hourglasses and water clocks, or clepsydras. In both, time is essentially measured by the uniform movement of sand or water. Small hourglasses are still found, but clepsydras gradually fell into disuse in the 17th century after high-precision mechanical pendulum clocks were invented.

What did ancient observatories look like?

<<< Назад

Forward >>>

ASTRONOMIC TOOLS

Astronomical instruments have been used since ancient times. With the beginning of the development of agriculture, when it was necessary to plan agricultural work. To do this, it was necessary to determine the moments of the equinoxes and solstices. At the same time, the needs of nomadic animal husbandry required the development of orientation methods. And for this, the stars, their movement were studied. Movement of the Sun and Moon. An example of the oldest observatory is the cult-astronomical structure near Ryazan. The equinoxes and solstices were recorded by the shadow from the Sun and its coincidence with certain pillars.

Such structures were built everywhere where the first farmers of Aria settled. But such ancient structures as the megaliths of Stonehenge have come down to us in the best possible way.

Ancient astronomical observatory Jantar-Mantar.

In principle, the device of these observatories is the same - the principle of sighting, that is, determining the direction by two points. However, these points were directed to the horizon. That is, the ancient observatories served the tasks of the calendar account of days.

However, already among pastoralists, and especially with the development of navigation, there is a need to study the sky itself. So already in the days of the ancient eastern despotisms (Sumer, Assyria, Babylon, Egypt), the principles of systematization of celestial objects arose. The ideas of the ecliptic arise. It is divided into 12 parts. Constellations are formed and names are given to them. And observatories are being built. They practically did not reach us, but Ulugbek's observatory was similar to them. In fact, this is an arc dug in the ground, on which the position of the stars was determined.

However, such a tool was useless for sailors. That is why hand-held astronomical instruments appear. It is known from history that in the second millennium BC. The Sea Peoples attacked Egypt. The peoples of the sea are the Pelasgians, Lelegs, Etruscans and other peoples who belonged to the Aryans of the Indo-Europeans. That is, our relatives-ancestors. They freely roamed the Mediterranean and Black Seas. And their ability to navigate, including the Sun and the stars, passed to the Greeks.

This is how they appeared: astronomical instruments or instruments: gnomon, armillary sphere, astrolabe, quadrant, octant, sextant, chronometer...

Vintage astronomical instruments
and navigation tools


armillary sphere	Astrolabe		Gnomon	Quadrant

Octant	Sextant	marine chronometer	Marine compass	Universal Tool

armillary spherethere is a collection of circles depicting the most important arcs celestial sphere. It aims to depict the relative position equator, ecliptic, horizon and other circles.

Astrolabe (from the Greek words: άστρον - luminary and λαμβάνω - I take), planisphere, analemma- a goniometric projectile used for astronomical and geodetic observations. A. was used by Hipparchus to determine the longitudes and latitudes of stars. It consists of a ring, which was installed in the plane of the ecliptic, and a ring perpendicular to it, on which the latitude of the observed luminary was measured, after the diopters of the instrument were pointed at it. On a horizontal circle, the difference in longitudes between a given luminary in some other was counted. In later times, A. was simplified, only one circle was left in it, by means of which navigators counted the height of stars above the horizon. This circle was hung on a ring in a vertical plane, and by means of an alidade equipped with diopters, stars were observed, the height of which was measured on a limb, to which a vernier was subsequently attached. Later, telescopes began to be used instead of diopters, and, gradually improving, A. moved to a new type of instrument - theodolite, which is now used in all those cases where some measurement accuracy is required. In the art of surveying A. still continues to be used, where, with sufficiently careful graduation, it allows you to measure angles with an accuracy of minutes of arc.

Gnomon(ancient Greek γνώμων - pointer) - the oldest astronomical instrument, a vertical object (stele, column, pole), which allows determining the angular height of the sun by the shortest length of its shadow (at noon).

Quadrant(lat. quadrans, -antis, from quadrare - to make quadrangular) - an astronomical instrument for determining the zenithal distances of the luminaries.

Octant(in maritime business - octane) - a goniometric astronomical instrument. The octant scale is 1/8 of a circle. The octant was used in nautical astronomy; practically out of use.

Sextant(sextan) - navigational measuring instrument, used to measure the height of a star above the horizon for the purpose ofdetermination of the geographical coordinates of the area in which measurement is made.

The quadrant, octant, and sextant differ only in the fraction of the circle (fourth, eighth, and sixth, respectively). Other than that, it's the same device. A modern sextant has an optical sight.

Astronomical compendium is a set of small tools for mathematical calculations in a single case. It provided the user with many options in a ready-made format. It was not a cheap set and obviously indicated the wealth of the owner. This elaborate piece was made by James Kinwin for Robert Devereux, second Earl of Essex (1567-1601), whose arms, crest and motto are engraved on inside covers. The compendium includes a passage instrument for determining the time of night from the stars, a list of latitudes, a magnetic compass, a list of ports and harbors, a perpetual calendar and a lunar indicator. The compendium could be used to determine the time, the height of the tide in ports, as well as calendar calculations. We can say that this is an ancient minicomputer.

Optical Instruments

A real revolution in astronomy began with the invention of the optical refracting telescope by Galileo. The word "telescope" is formed from two Greek roots and can be translated into Russian as "look into the distance." Indeed, this optical device is a powerful spotting scope designed to observe very distant objects - celestial bodies. Created about four hundred years ago, the telescope is a kind of symbol modern science, embodying the eternal desire of mankind for knowledge. Giant telescopes and grandiose observatories make a significant contribution to the development of entire areas of science devoted to the study of the structure and laws of our Universe. However, today the telescope can be increasingly found not in a scientific observatory, but in an ordinary city apartment, where an ordinary amateur astronomer lives, who goes on clear starry nights to join the breathtaking beauties of space.

Although there is indirect evidence that optical devices designed to study the stars were already known to some ancient civilizations, the official birth date of the telescope is considered to be 1609. It was in this year that Galileo Galilei, experimenting with lenses to create glasses, found a combination that provided multiple zooms. The first spotting scope built by the scientist became the progenitor of modern refractors and subsequently received the name of the telescope.

Galileo's telescope was a lead tube with two lenses: plano-convex, which served as an objective, and plano-concave, which served as an eyepiece. The first telescope of Galileo provided a direct image and only a threefold increase, but later the scientist managed to create a device that brought objects closer to 30 times. With the help of his telescope, Galileo discovered four satellites of Jupiter, the phases of Venus, irregularities (mountains, valleys, cracks, craters) on the surface of the Moon, spots on the Sun. Subsequently, the design of the Galilean telescope was improved by Kepler, who created an instrument that offered an inverted image, but with a much larger field of view and magnification. The lens telescope was further improved: to improve image quality, astronomers used the latest technology glassmaking, and also increased the focal length of telescopes, which naturally led to an increase in their physical dimensions (for example, at the end of the 18th century, the length of the telescope of Jan Hevelius reached 46 m).

The first mirror telescope also appeared in the 17th century. This instrument was invented by Sir Isaac Newton, who, considering chromatism to be a fatal problem with refracting telescopes, decided to move in a different direction. In 1668, after much experimentation with alloys and mirror polishing techniques, Newton demonstrated the first mirror telescope, which, at only 15 cm long and 25 mm in diameter, performed just as well as a long refractor telescope. Although the image created by Newton's first telescope was dim and not bright enough, subsequently the scientist managed to significantly improve the characteristics of his device.

In an effort to improve the design of the telescope in such a way as to achieve the highest possible image quality, scientists have created several optical designs that use both lenses and mirrors. Among such telescopes, the catadioptric systems of Newton, Maksutov-Cassegrain and Schmidt-Cassegrain are most widely used, which will be discussed in more detail below.

Telescope design

A telescope is an optical system that "grabs" a small area from space, visually bringing objects located in it closer. The telescope captures the rays of the light flux parallel to its optical axis, collects them at one point (focus) and magnifies them with the help of a lens or, more often, a lens system (eyepiece), which simultaneously converts the diverging light rays into parallel again.

According to the type of element used to collect light rays in focus, all modern consumer telescopes are divided into lens (refractors), mirror (reflectors) and mirror-lens (catadioptric). The capabilities of the telescopes of each group are somewhat different, therefore, in order to choose the best optical instrument for their needs, a novice amateur astronomer should have some idea of \u200b\u200bits device.

Lens telescopes (refractors)

Following their progenitor created by Galileo, the telescopes of this group focus light with the help of one or more lenses, as a result of which they are called lens, or refractors.

Refractors have a number of advantages over telescopes of other systems. Thus, a closed telescope tube prevents dust and moisture from penetrating inside the tube, which have a negative effect on beneficial features telescope. In addition, refractors are easy to maintain and operate - the position of their lenses is fixed at the factory, which eliminates the need for the user to independently adjust, that is, fine-tune. Finally, lens telescopes lack central shielding, which reduces the amount of incoming light and leads to distortion of the diffraction pattern. Refractors provide high contrast and excellent image resolution for planetary observations. However, the telescopes of this system also have disadvantages, the main of which is an effect known as chromatic aberration. It arises due to the fact that light rays of different lengths have unequal convergence, that is, the focus points for different components of the spectrum will be located on different distance from a refractive lens. Visual chromatic aberration appears as colored halos around bright objects. To eliminate this defect, additional lenses and optical elements made of special types of glass must be used. But the design of refractors itself involves at least two lenses, all four surfaces of which must have a well-calibrated curvature, be carefully polished and coated with at least one antireflection layer. In other words, a good refractor is a device that is quite difficult to manufacture, and therefore, as a rule, very expensive.

Mirror telescopes (reflectors)

Telescopes of another large group collect a light beam with the help of a mirror, therefore they are called mirror telescopes, reflectors. The most popular design of a reflecting telescope is named after its inventor, the Newtonian telescope.

The mirror as an element of the optical system of the reflector is a concave parabolic glass plate, the front surface of which is covered with a reflective material. When using spherical mirrors in such constructions, the light reflected by their surface does not converge at one point, forming a slightly blurred spot in focus. As a result, the image loses contrast, that is, an effect known as spherical aberration occurs.

Parabolic shaped mirrors help prevent deterioration in image quality. In the left picture, the light reflected by spherical mirrors does not converge at one point, which leads to a deterioration in sharpness. In the right picture, paraboloid mirrors collect all the rays into a single focus point.

Light entering the telescope hits a mirror, which reflects the rays upward. Light is reflected to the focal point by
a flat elliptical secondary mirror fixed in the center of the tube at an angle of 45 degrees. Of course, the secondary mirror itself cannot be seen through the eyepiece, but it is an obstacle to the light flux and screens the light, which can change the diffraction pattern and lead to a slight loss of contrast. Among the advantages of reflectors is the absence of chromatism, because the rays of light, by virtue of the design itself, are reflected from the glass, and do not pass through it. In addition, compared to refractors, mirror telescopes are less expensive to manufacture: the reflector design contains only two surfaces that need polishing and special coatings.

Catadioptric telescopes are optical systems that combine lenses and mirrors. Newton catadioptric telescopes, Schmidt-Cassegrain and Maksutov-Cassegrain telescopes are presented here.

Mirror-lens telescopes of the Newtonian system differ from the classical representatives of their class by the presence of a corrective lens on the way of the light flux to the focus point, which, while maintaining compact dimensions telescope, allows you to achieve greater magnification. For example, using a 2x corrective lens and a physical system length of 500mm would result in a focal length of 1000mm. Such reflectors are much lighter and more compact than "normal" Newtonian telescopes of the same focal length, and, in addition, they are easy to use.
operation, easy to install and less exposed to wind. The position of the corrective lens is fixed during the manufacturing process, but the mirrors, as with a standard Newtonian telescope, need to be adjusted regularly.

Optical schemes Schmidt-Cassegrain telescopes include thin aspherical correction plates that direct light onto the primary concave mirror to correct for spherical aberration. After that, the light rays fall on the secondary mirror, which, in turn, reflects them down, directing them through the hole

at the center of the primary mirror. Directly behind the primary mirror is an eyepiece or diagonal mirror. Focusing is done by moving the primary mirror or eyepiece. The main advantage of telescopes of this design is the combination of portability and large focal length. The main disadvantage of Schmidt-Cassegrain telescopes is the relatively large secondary mirror, which reduces the amount of light and can cause some loss of contrast.

Maksutov-Cassegrain telescopes have a similar design. Just like Schmidt-Cassegrain systems, these models correct spherical aberration using a corrector, which, instead of a Schmidt plate, uses a thick convex-concave lens (meniscus). Passing through the concave side of the meniscus, the light enters the primary mirror, which reflects it up to the secondary mirror (usually a mirrored area on the convex side of the meniscus). Further, just as in the Schmidt-Cassegrain design, the light rays pass through the hole in the primary mirror and enter the eyepiece. Telescopes of the Maksutov-Cassegrain system are less difficult to manufacture than the Schmidt-Cassegrain models, but the use of a thick meniscus in the optical scheme increases their weight.

Modern telescopes

Most modern telescopes are reflectors.

Currently, the world's largest reflecting telescopes are the two Keck telescopes located in Hawaii. Keck-I and Keck-II entered service in 1993 and 1996 respectively and have an effective mirror diameter of 9.8 m. The telescopes are located on the same platform and can be used together as an interferometer, giving a resolution corresponding to a mirror diameter of 85 m.

The largest solid-mirror telescope in the world is the Large Binocular Telescope, located on Mount Graham (USA, Arizona). The diameter of both mirrors is 8.4 meters.

On October 11, 2005, the Southern African Large Telescope in South Africa was put into operation with a main mirror measuring 11 x 9.8 meters, consisting of 91 identical hexagons.

Very big Telescope	Canarian telescope	Telescope Hobby Eberle	Gemini	SUBARU	SALT

radio telescopes

Until the end of the Great Patriotic War, astronomical research was carried out only in the optical range using optical telescopes. However, already during the Second World War, radar stations began to be developed for the needs of detecting enemy aircraft. After the war, it was discovered that air defense radar stations also detected some strange signals. These signals were found to be coming from outer space. And so began the use of radio devices to explore the universe. Such devices are called radio telescopes. With their help, they discovered radio stars - quasars, so they discovered relic radiation, radiation from the Sun, the center of the galaxy, etc. etc. Radio telescopes have become a powerful tool for understanding the universe. And a great many of them have been built.

At first, these were small parabolic antennas:

Then more on towers with azimuth settings:

Then huge, with trusses turning on rails:

Sector, where part of the antenna paraboloid was mounted directly on the ground:

Radio telescopes began to be used together, when the total power of individual telescopes was added, giving the power and resolution of a larger telescope:

They began to create gratings from individual telescopes,
which increased the resolution of the system:

In addition to parabolic antennas, lattice antennas began to be made:

Space radio telescopes:

The world's largest radio telescope

The radio telescope installed in Arecibo is currently the largest in the world (of those using a single aperture). The telescope is used for research in the field of radio astronomy, atmospheric physics and radar observations of objects in the solar system. The Arecibo Astronomical Observatory is located in Puerto Rico, 15 km from Arecibo, at an altitude of 497 m above sea level. Research is being conducted by Cornell University in cooperation with the National Science Foundation.

Design features: The reflector of the telescope is located in a natural sinkhole and is covered with 38778 perforated aluminum plates (from 1 to 2 m) laid on a grid of steel cables. The antenna feed is movable, suspended on 18 cables from three towers. The observatory has a transmitter with a power of 0.5 MW for conducting research under the program of radar astronomy. The construction of the radio telescope began in 1960. The original purpose of the telescope was to study the Earth's ionosphere. The author of the idea of construction: Cornell University professor William Gordon. The official opening of the Arecibo Observatory took place on November 1, 1963.

Going beyond the optical range by radio astronomy immediately raised the question of using other ranges of electromagnetic radiation. In general, we can obtain information about space in two ways - through electromagnetic radiation and corpuscular flows (flows of elementary particles). There have been attempts to capture gravitational waves as well, but so far without success.

Electromagnetic radiation is divided into:

radio waves,

infrared radiation,

light range,

ultraviolet radiation,

X-Ray Radiation,

gamma radiation.

Infrared (thermal) and ultraviolet radiation can be reflected by an ordinary mirror, so ordinary reflector telescopes are used, but the image is perceived by special temperature-sensitive sensors and ultraviolet radiation sensors.

X-ray and gamma radiation is another matter. X-ray and gamma-ray telescopes are special instruments:

Astronomy and astronautics.

The main problem of observational astronomy is the earth's atmosphere. It is not completely transparent. It moves, including due to heat. Clouds and precipitation are frequent. There is a lot of dust, insects, etc. in the atmosphere. Therefore, it has always been a dream of astronomers to be able to place their instruments as high as possible. As high as possible in the mountains, on planes and balloons. But a real revolution in this problem occurred with the launch of an artificial Earth satellite by the Soviet Union. Almost immediately, astronomers and astrophysicists rushed to seize the opportunity. First of all, by launching space probes to the Moon, Venus, Mars and beyond, and beyond.

Briefly about the study of the Moon by Soviet scientists is set out on the page dedicated to the Moon.

The study of the solar system with the help of automatic probes is a separate issue. Here we present the most famous astronomical instruments launched into orbit around the Earth.


Hubble	Herschel	Chandra	WISE	Spektr-R	Garnet

(source http://grigam.narod.ru)

ASTRONOMIC TOOLS

Such structures were built everywhere where the first farmers of Aria settled. But such ancient structures as the megaliths of Stonehenge have come down to us in the best possible way.

Ancient astronomical observatory Jantar-Mantar.

This is how they appeared: astronomical instruments or instruments: gnomon, armillary sphere, astrolabe, quadrant, octant, sextant, chronometer...

Vintage astronomical instruments
and navigation tools


armillary sphere	Astrolabe		Gnomon	Quadrant

Octant	Sextant	marine chronometer	Marine compass	Universal Tool

armillary spherethere is a collection of circles depicting the most important arcs celestial sphere. It aims to depict the relative position equator, ecliptic, horizon and other circles.

Quadrant(lat. quadrans, -antis, from quadrare - to make quadrangular) - an astronomical instrument for determining the zenithal distances of the luminaries.

Octant(in maritime business - octane) - a goniometric astronomical instrument. The octant scale is 1/8 of a circle. The octant was used in nautical astronomy; practically out of use.

The quadrant, octant, and sextant differ only in the fraction of the circle (fourth, eighth, and sixth, respectively). Other than that, it's the same device. A modern sextant has an optical sight.

Astronomical compendium is a set of small tools for mathematical calculations in a single case. It provided the user with many options in a ready-made format. It was not a cheap set and obviously indicated the wealth of the owner. This elaborate piece was made by James Kinwin for Robert Devereux, second Earl of Essex (1567-1601), whose arms, crest and motto are engraved on the inside of the lid. The compendium includes a passage instrument for determining the time of night from the stars, a list of latitudes, a magnetic compass, a list of ports and harbors, a perpetual calendar and a lunar indicator. The compendium could be used to determine the time, the height of the tide in ports, as well as calendar calculations. We can say that this is an ancient minicomputer.

Optical Instruments

A real revolution in astronomy began with the invention of the optical refracting telescope by Galileo. The word "telescope" is formed from two Greek roots and can be translated into Russian as "look into the distance." Indeed, this optical device is a powerful spotting scope designed to observe very distant objects - celestial bodies. Created about four hundred years ago, the telescope is a kind of symbol of modern science, embodying the eternal desire of mankind for knowledge. Giant telescopes and grandiose observatories make a significant contribution to the development of entire areas of science devoted to the study of the structure and laws of our Universe. However, today the telescope can be increasingly found not in a scientific observatory, but in an ordinary city apartment, where an ordinary amateur astronomer lives, who goes on clear starry nights to join the breathtaking beauties of space.

Galileo's telescope was a lead tube with two lenses: plano-convex, which served as an objective, and plano-concave, which served as an eyepiece. The first telescope of Galileo provided a direct image and only a threefold increase, but later the scientist managed to create a device that brought objects closer to 30 times. With the help of his telescope, Galileo discovered four satellites of Jupiter, the phases of Venus, irregularities (mountains, valleys, cracks, craters) on the surface of the Moon, spots on the Sun. Subsequently, the design of the Galilean telescope was improved by Kepler, who created an instrument that offered an inverted image, but with a much larger field of view and magnification. The lens telescope was further improved: in order to improve the image quality, astronomers used the latest glass-making technologies, and also increased the focal length of telescopes, which naturally led to an increase in their physical dimensions (for example, at the end of the 18th century, the length of the telescope of Jan Hevelius reached 46 m).

Telescope design

Lens telescopes (refractors)

Following their progenitor created by Galileo, the telescopes of this group focus light with the help of one or more lenses, as a result of which they are called lens, or refractors.

Refractors have a number of advantages over telescopes of other systems. Thus, a closed telescope tube prevents dust and moisture from penetrating inside the tube, which have a negative effect on the useful properties of the telescope. In addition, refractors are easy to maintain and operate - the position of their lenses is fixed at the factory, which eliminates the need for the user to independently adjust, that is, fine-tune. Finally, lens telescopes lack central shielding, which reduces the amount of incoming light and leads to distortion of the diffraction pattern. Refractors provide high contrast and excellent image resolution for planetary observations. However, the telescopes of this system also have disadvantages, the main of which is an effect known as chromatic aberration. It arises due to the fact that light rays of different lengths have unequal convergence, that is, the focus points for different components of the spectrum will be at different distances from the refractive lens. Visual chromatic aberration appears as colored halos around bright objects. To eliminate this defect, additional lenses and optical elements made of special types of glass must be used. But the design of refractors itself involves at least two lenses, all four surfaces of which must have a well-calibrated curvature, be carefully polished and coated with at least one antireflection layer. In other words, a good refractor is a device that is quite difficult to manufacture, and therefore, as a rule, very expensive.

Mirror telescopes (reflectors)

Catadioptric telescopes are optical systems that combine lenses and mirrors. Newton catadioptric telescopes, Schmidt-Cassegrain and Maksutov-Cassegrain telescopes are presented here.

Mirror-lens telescopes of the Newtonian system differ from classical representatives of their class by the presence of a corrective lens on the path of the light flux to the focal point, which, while maintaining the compact dimensions of the telescope, allows achieving higher magnification. For example, using a 2x corrective lens and a physical system length of 500mm would result in a focal length of 1000mm. Such reflectors are much lighter and more compact than "normal" Newtonian telescopes of the same focal length, and, in addition, they are easy to use.
operation, easy to install and less exposed to wind. The position of the corrective lens is fixed during the manufacturing process, but the mirrors, as with a standard Newtonian telescope, need to be adjusted regularly.

Modern telescopes

Most modern telescopes are reflectors.

The largest solid-mirror telescope in the world is the Large Binocular Telescope, located on Mount Graham (USA, Arizona). The diameter of both mirrors is 8.4 meters.

On October 11, 2005, the Southern African Large Telescope in South Africa was put into operation with a main mirror measuring 11 x 9.8 meters, consisting of 91 identical hexagons.

Very big Telescope	Canarian telescope	Telescope Hobby Eberle	Gemini	SUBARU	SALT

radio telescopes

At first, these were small parabolic antennas:

Then more on towers with azimuth settings:

Then huge, with trusses turning on rails:

Sector, where part of the antenna paraboloid was mounted directly on the ground:

Radio telescopes began to be used together, when the total power of individual telescopes was added, giving the power and resolution of a larger telescope:

They began to create gratings from individual telescopes,
which increased the resolution of the system:

In addition to parabolic antennas, lattice antennas began to be made:

Space radio telescopes:

The world's largest radio telescope

Electromagnetic radiation is divided into:

radio waves,

infrared radiation,

light range,

ultraviolet radiation,

X-Ray Radiation,

gamma radiation.

X-ray and gamma radiation is another matter. X-ray and gamma-ray telescopes are special instruments:

Astronomy and astronautics.

Briefly about the study of the Moon by Soviet scientists is set out on the page dedicated to the Moon.

The study of the solar system with the help of automatic probes is a separate issue. Here we present the most famous astronomical instruments launched into orbit around the Earth.


Hubble	Herschel	Chandra	WISE	Spektr-R	Garnet

(source http://grigam.narod.ru)