home · electrical safety · History of science in instruments: Astrolabe. The astrolabe is an ancient astronomical instrument. The astrolabe is used in science and technology.

History of science in instruments: Astrolabe. The astrolabe is an ancient astronomical instrument. The astrolabe is used in science and technology.

Many people believe that our civilization is a source of constant progress, and all the most interesting discoveries and developments are yet to come. However, deep philosophical works, some masterpieces of architecture and even devices created long before us clearly highlight the incompleteness of this concept. Ancient scientists also knew a lot; they created buildings and things, the principle of operation and purpose of which were not fully understood. The clear consistency of the functioning of certain devices with the laws of physics and the irrefutability of the information obtained with their help are often shrouded in legends. Such instruments include the astrolabe, an ancient astronomical instrument.

Purpose

As the name suggests (“aster” means “star” in Greek), the device is associated with the study celestial bodies. Indeed, an astrolabe is a tool that allows you to calculate at what height relative to the surface of our planet the stars and the Sun are located, and, based on the data obtained, determine the location of a particular earthly object. On long journeys by land and sea, the astrolabe helped determine coordinates and time, and sometimes served as the only reference point.

Structure

The astronomical instrument consists of a disk, which is a stereographic projection of the starry sky, and a circle with a high side in which the disk is embedded. The base of the device (an element with a side) has a small hole in the central part, as well as a hanging ring, which is necessary to facilitate the orientation of the entire structure relative to the horizon. The middle part is composed of several circles with lines and dots applied to them, defining latitude and longitude. These discs are called tympana. The goniometer astronomical instrument had three such elements, each of them suitable for a specific latitude. The order in which the tympanums were inserted depended on the location: the upper disk was supposed to contain a projection of the sky corresponding to a given area of ​​the Earth.

On top of the tympanum there was a special lattice (“spider”), equipped with a large number of arrows pointing to the brightest stars indicated on the projection. An axis passing through the holes in the center of the tympanums, lattice and base held the parts together. An alidade was attached to it - a special ruler for calculations.

The accuracy of the astrolabe's readings is amazing: some instruments, for example, are capable of showing not just the movement of the Sun, but also the deviations that periodically occur in it. It is interesting that the ancient astronomical instrument was created at a time when the geocentric picture of the world reigned. However, the idea that everyone revolves around the Earth did not prevent ancient scientists from creating such an accurate device.

A little history

The astronomical instrument has a Greek name, but many of its components have names of Arabic origin. The reason for this apparent discrepancy is the long journey that the device has covered during its development.

The history of the development of astronomy, like many other sciences, is inextricably linked with Ancient Greece. Here, about two centuries before the beginning of our era, the prototype of the astrolabe appeared. Its creator was Hipparchus. Already in the second century after the birth of Christ, a description of a goniometer similar to the astrolabe was made by Claudius Ptolemy. He also built an instrument capable of determining the sky.

These first instruments were somewhat different from the astrolabes that modern people imagine them to be and which are exhibited in many museums around the world. The first instrument of the usual structure is considered to be the invention of Theon of Alexandria (IV century AD)

Eastern sages

The history of the development of astronomy in the early Middle Ages began to unfold in the territory. This was due to the persecution of scientists by the church, with instruments like the astrolabe being attributed to Satanic origin.

The Arabs improved the device and began to use it not only to determine the location of stars and orientation on the ground, but also as a time meter, a tool for some mathematical calculations, and a source of astrological predictions. The wisdom of East and West merged, the result was the astrolabe device, which combined European heritage with Arab thought.

The Pope and the Devil's Instrument

One of the Europeans who sought to revive the astrolabe was Herbert of Aurillac (Sylvester II), who briefly held the post of He studied the achievements of Arab scientists, learned to use many instruments that had been forgotten since antiquity or prohibited by the church. His talents were recognized, but his connection with alien Islamic knowledge contributed to the emergence of a number of legends around him. Herbert was suspected of having a relationship with a succubus and even the devil. The first endowed him with knowledge, and the second helped him take such a high position in which the Evil One was credited with his ascension. Despite all the rumors, Herbert managed to revive a number of important instruments, including the astrolabe.

Return

Some time later, in the 12th century, Europe began to use this device again. At first, only the Arabic astrolabe was in use. For many it was a new instrument and only for a few it was a forgotten and modernized heritage of their ancestors. Locally produced analogues gradually began to appear, as well as long scientific works related to the use and design of the astrolabe.

The peak of the device's popularity occurred during the era of the Great Discoveries. A naval astrolabe was in use, which helped determine where the ship was. True, it had a feature that negated the accuracy of the data. Columbus, like many of his contemporaries who traveled by water, complained that this device could not be used in rolling conditions; it was effective only when the ground was motionless underfoot or the sea was completely calm.

The device was still of some value to seafarers. Otherwise, one of the ships on which the expedition of the famous explorer Jean-François La Perouse set off on a voyage would not have been named after him. The Astrolabe ship is one of two that took part in the expedition and mysteriously disappeared at the end of the eighteenth century.

Decoration

With the advent of the Renaissance, not only various devices for exploring the world around us, but also decorative items and a passion for collecting received amnesty. The astrolabe is a device, among other things, often used to predict fate by the movements of the stars, and therefore it was decorated with various symbols and signs. Europeans adopted from the Arabs the habit of creating instruments that were accurate in terms of measurements and elegant in appearance. Astrolabes began to appear in the collections of courtiers. Knowledge of astronomy was considered the basis of education; the possession of an instrument emphasized the erudition and taste of the owner.

The crown of the collection

The most beautiful devices were inlaid precious stones. The signs were shaped like leaves and curls. Gold and silver were used to decorate the instrument.

Some craftsmen devoted themselves almost entirely to the art of creating astrolabes. In the 16th century, the Flemish Gualterus Arsenius was considered the most famous of them. For collectors, his products were the standard of beauty and grace. In 1568, he was commissioned to create another astrolabe. The device for measuring the positions of stars was intended for Austrian Army Colonel Albrecht von Wallenstein. Today it is kept in the museum named after. M.V. Lomonosov.

Shrouded in mystery

The astrolabe, one way or another, appears in many legends and mystical events of the past. Thus, the Arab stage of its history gave the world the myth of the treacherous Sultan and the scientific abilities of the court astrologer Biruni. The ruler, for a reason hidden over the centuries, took up arms against his fortuneteller, and decided to use cunning to get rid of him. The astrologer had to indicate exactly which exit from the hall his owner would use, or suffer fair punishment. In his calculations, Biruni used an astrolabe and, having written the result on a piece of paper, hid it under the carpet. The cunning Sultan ordered his servants to cut a passage in the wall and went out through it. When he returned, he opened the fortune paper and read a message there that predicted all his actions. Biruni was acquitted and released.

The inexorable movement of progress

Today, the astrolabe is part of astronomy's past. Orientation to the terrain with its help ceased to be advisable already with early XVIII century, when the sextant appeared. The device was still used periodically, but after another century or a little more, the astrolabe finally migrated to the shelves of collectors and lovers of antiquities.

Modernity

An approximate understanding of the structure and functioning of the device is given by its modern descendant - the planisphere.

This is a map with stars and planets on it. Its components, stationary and moving parts, are in many ways reminiscent of the base and disk. For determining correct position To locate the luminaries in a specific part of the sky, an upper moving element is required that corresponds in parameters to the desired latitude. The astrolabe is oriented in a similar way. You can even make something like a planisphere with your own hands. Such a model will also give an idea of ​​the capabilities of its ancient predecessor.

Living legend

A ready-made astrolabe can be bought in souvenir shops, sometimes it appears in collections decorative items, based on the sim-punk style. Unfortunately, working devices are difficult to find. Planispheres are also rare on our store shelves. Interesting examples can be found on foreign websites, but such a moving map will cost the same as that cast-iron bridge. Constructing a model yourself can be a time-consuming task, but the result is worth it and children will definitely like it.

The starry sky, which so comprehensively occupied the minds of the ancients, amazes with its beauty and mystery and modern man. Devices such as the astrolabe make it a little closer to us, a little more understandable. A museum or souvenir version of the device also makes it possible to experience the wisdom of our ancestors, who two thousand years ago created instruments that made it possible to quite accurately display the world and find our place in it.

Today the astrolabe - stylish souvenir, interesting for its history and eye-catching with its unusual design. Once upon a time, this was a significant breakthrough in astronomy, allowing one to correlate the position of celestial bodies with the terrain, practically the only chance of understanding where a traveler was lost in the vastness of the ocean or desert. And even though the device is significantly inferior in functional terms to its modern analogues, it will always be significant part history, a subject shrouded in a romantic veil of mystery, and therefore is unlikely to be lost through the ages.

Secrets and history ancient invention. Astrolabe

The astrolabe is one of the oldest astronomical instruments, dating back to Ancient Greece. This ancient instrument was created more than two thousand years ago, when people believed that the Earth was the center of the Universe.

The astrolabe is sometimes called the very first computer. Undoubtedly, this is a device with the deepest mystery and beauty, and we will now try to learn its secrets.

The first astrolabe appeared in Ancient Greece. Vitruvius, in his writing “Ten Books on Architecture,” talking about an astronomical instrument called a “spider,” says that it was “invented by the astronomer Eudoxus, while others say Apollonius.” One of the main parts of this instrument was a drum, where the sky with the zodiac circle was drawn.

Stereographic projection was described in the 2nd century AD. e. Claudius Ptolemy in his work “Planispherium”. However, Ptolemy himself called another instrument “astrolabon” - the armillary sphere.

The final type of astrolabe was developed in the 4th century. n. e. Thus, in Alexandria, almost three hundred years after Ptolemy, the mathematician and philosopher Hypatia was condemned by Christian society for satanic rituals, including, among other things, the use of an astrolabe. She was executed in 415 AD. Her student, Theon of Alexandria, left behind copies of notes on the use of the astrolabe.

After the death of Hypatia and after the fall of the Roman Empire, Europe “lost” the astrolabe. Most ancient Greek knowledge was lost in Western Europe, whose population regarded ancient Greek (and therefore atheist) technology with great suspicion. However, it was carefully guarded by adherents of Islam; their use of the astrolabe is confirmed by many facts. Without Spain and its Islamic religion, the Renaissance would never have come. Most of the ancient Greek texts found have been translated into Arabic. They were later translated into Latin, and the astrolabe was then reintroduced to the vast majority of Europeans.

Scientists of the Islamic East improved the astrolabe and began to use it not only to determine the time and duration of day and night, but also to carry out some mathematical calculations and for astrological predictions. There are many known works of medieval Islamic authors about various designs and the use of the astrolabe.

These are the books of al-Khorezmi, al-Astrulabi, az-Zarqali, as-Sijizi, al-Fargani, as-Sufi, al-Biruni, Nasir ad-Din at-Tusi and others.

Since the 12th century, astrolabes became known in Western Europe, where they first used Arabic instruments, and later began to make their own according to Arabic models. In the 16th century they began to be made based on their own calculations in order to be used in European latitudes.

The astrolabe reached its peak of popularity in Europe during the Renaissance, in the 15th-16th centuries; along with the armillary sphere, it was one of the main tools for astronomical education.

Knowledge of astronomy was considered the basis of education, and the ability to use an astrolabe was a matter of prestige and a sign of appropriate education. European masters, like their Arab predecessors, paid great attention decoration, so that astrolabes became fashion items and collectibles at royal courts.

It would be pointless to describe exactly how the astrolabe works - it is best if you see it with your own eyes.

Shuttle-shaped astrolabe.

As al-Biruni wrote, the design of this astrolabe, invented by al-Sijizi, comes “from the conviction of some people that the ordered movement of the Universe belongs to the Earth, and not to the celestial sphere.” The ecliptic and stars are depicted on its tympanum, and the horizon and almucantarata are depicted on the movable part.

The photo shows an Arabian astrolabe 1090, from the collection of the National Museum of American.

The perfect astrolabe.

In this astrolabe, invented by al-Saghani, the center of projection is not the north pole of the world, but an arbitrary point on the celestial sphere. In this case, the main circles of the sphere are depicted on the tympanum no longer by circles and straight lines, but by circles and conical sections.
Astrolabe. Secrets and history of an ancient invention

Universal astrolabe.

In this astrolabe, invented by al-Zarqali, one of the equinox points is taken as the design center. In this case, the celestial equator and the ecliptic are depicted on the tympanum by straight lines. The tympanum of this astrolabe, unlike the tympanums of ordinary astrolabes, is suitable for any latitude. The functions of the spider of an ordinary astrolabe here are performed by a ruler rotating around the center of the tympanum and called the “moving horizon”.

Spherical astrolabe.

The celestial sphere is represented in this astrolabe as a sphere, and its spider is also spherical.

Observational astrolabe.

This astrolabe is a combination of an armillary sphere and a regular astrolabe, embedded in a ring representing the meridian.

Linear astrolabe.

This astrolabe, invented by Sharaf al-Din al-Tusi, is a rod with several scales, with sighting threads attached to it.

Marine astrolabe.

This device, invented by Portuguese craftsmen at the beginning of the 15th century, is a purely observational device and is not intended for analog calculations.

Marine astrolabe.

The photo shows an astrolabe-quadrant, 1325.

Modern encyclopedias say that this device is designed to determine the latitude of a place. In fact, the functions of the astrolabe are much more diverse: it can rightfully be called the computer of a medieval astronomer. Exact number most likely no one can name the functions of the astrolabe, since different types astrolabe could be performed different kinds works Back in the 10th century, the Arab scholar al-Sufi wrote a detailed treatise consisting of 386 chapters, in which he listed 1000 ways to use the astrolabe.

Perhaps he exaggerated slightly, but not by much. After all, with the help of this unique tool it was possible:

— recalculate the ecliptic coordinates of stars or the Sun into horizontal ones (i.e. determine their altitudes and azimuths);

- using observations of the stars and the Sun through a special viewfinder, determine the latitude of a place, directions to different cities (mainly to calculate the direction to Mecca), determine the time of day, determine sidereal time;

- determine the moments of sunrise and sunset, i.e. the beginning and end of the day, as well as the moments of star rise, and if there were ephemerides, then of the planets; determine the ascending and setting degrees of the ecliptic, i.e. ascendant and descendant, build horoscope houses;

- determine the latitude of an area by measuring the height of the Sun at noon or the heights of the stars at its climax (I’m not sure if this was done often, since using an astrolabe for this purpose is reminiscent of shooting sparrows from a cannon);
— solve purely earthly problems, such as measuring the depth of a well or the height of an earthly object; and also calculate trigonometric functions(sines, cosines, tangents, cotangents).
- make transformations between three coordinate systems - equatorial (right ascension and declination), ecliptic (longitude, latitude) and horizontal (azimuth, altitude), and much, much more...

This is how the traditional planispheric astrolabe, usually made of brass, was constructed:

The body most often had a thickness of about 6 mm and a diameter of 15 - 20 cm (for the largest astrolabes - up to 50 cm). Although more substantial instruments with a diameter of 30-40 cm were often found, a giant specimen of 85 cm in diameter was known, and, conversely, miniature pocket versions with a diameter of only 8 cm. The fact is that its accuracy directly depended on the size of the astrolabe.

The photo shows an example of how to assemble a simple astrolabe.

In the photo, the Astrolabe by Mahmud ibn Shawka al-Baghdadi 1294-1295 diameter - 96 mm. From the collection of the National Maritime Museum, London

During the heyday of the Arab world, time was measured during the day using a sundial, and at night using a water or sand clock. The astrolabe made it possible to reconcile these watches. To do this, it was necessary to observe the height of the Sun during the day, and at night - one of bright stars, printed on the “spider” of the astrolabe. An interesting device based on the same astrolabe, which can be called a prototype of a mechanical watch, was developed by the famous Arab scientist Al-Biruni. He proposed an astrolabe diagram that automatically showed mutual arrangement Sun and Moon, i.e. lunar phase. The instrument had double body, inside which the gears were fixed. If you rotate the outer disk at a certain speed, you can see the change in the window lunar phases. Later, astrolabes appeared, equipped with gears that simulated the movement of planetary spheres. True, at that time there was no reliable mechanical drive, so the device was fully implemented only in medieval Europe, when the weight and spring drives were invented. And the first mechanical watches, often installed on towers cathedrals in Europe, for a long time were made in the form of astrolabes.

And this is not surprising - after all, complex Arabic astrolabes have turned into real works of art. The star pointers looked not just pins, but spirals and curls in the shape of leaves. The circumference of the instrument was inlaid with precious stones and sometimes trimmed with gold and silver. And all because often a court astrologer would appear with an astrolabe before the menacing eyes of some vizier or shah. An excellent instrument gave weight to the astrologer’s predictions, and not only the fate of the predictor himself depended on this, but also the development of astronomy, more often called then simply the science of the stars.

Pictured is a Persian astrolabe from 1223.

The incident that allegedly happened to Biruni became a legend. One day, an insidious ruler decided to deal with the unwanted scientist and demanded from him an answer to the question: “Which door - northern or southern - will he leave the hall from?” After performing a series of manipulations with the astrolabe, the resourceful Biruni replied that it would be cut through new door. The answer turned out to be correct. But more often than not, rulers were generous to their court astrologers, allocating money for the construction of observatories and the creation of all kinds of zijs - ephemeris tables. All this led, albeit to a small extent, to progress in astronomy.

In the photo is a French astrolabe from the late 16th - early 17th centuries.

The modern descendant of the astrolabe is the planisphere - a movable map of the starry sky, used for educational purposes.

Despite the huge number of regularly updated inventions, nanotechnologies and other modern technology, retro is still in fashion. This style can include various fixtures, devices, furniture, clothing and even cars. Antiques are highly valued and are perceived by many admirers of this style as something incredible and miraculous. A similar aura of mystery surrounds such unusual instrument like an astrolabe. This is real ancient computer, which not many people know about.

Briefly about the item and its purpose

An astrolabe is a device for measuring horizontal angles, establishing the latitude and longitude of celestial bodies. It is the oldest astronomical instrument ever invented in human history. This device is based on the principle of stereographic projection. The modern prototype of the astrolabe is the planisphere. It is a moving map of the starry sky. It is usually used for student learning purposes.

History of the item's origin

The very first astrolabe device was discovered in Ancient Greece. Vitruvius first spoke about it. In his writing “Ten Books on Architecture,” he admiringly described a certain instrument, which the author called a “spider.”

According to the author, the instrument was very unusual in appearance and caused certain fears among others. Many of the people who have ever encountered this device have spoken of it as a divine artifact. Among the first authors to write treatises on this device were theologians and philosophers John Philoponus, Synesius and Severus Sebokht.

Who invented the device?

If everything is more or less clear about who invented the astrolabe, then the design of the device raised a number of questions. So, what did the table, an unusual object for that time, look like?

This device was round in shape and consisted of various grooves, small parts and gears. In the center of the object was a large drum and a circle. It was on it that the entire zodiac circle was depicted. According to an alternative version of Claudius Ptolemy, the device resembled an armillary sphere.

And only after a long time the model was refined by the Greek mathematician Theon of Alexandria. This was in the 4th century AD. True, at that time the device received a different name - “small astrolabon”.

Device improvement

Later, the astrolabe device was refined and improved. Scientists and mathematicians of the Islamic East worked on it. Thanks to their innovations, with the help of this item it was possible to determine the time of day, the duration of the night and day, and perform simple calculations to make an astrological forecast. More and more stories and writings began to appear about this device. For example, Nasir ad-Dina al-Tusi, al-Khorezmi, al-Sijizi and other eastern authors wrote about him.

Travel to Europe

Over time, the popularity of the astrolabe compass is only growing. She reaches the shores Western Europe. On that moment in great demand enjoyed various instruments Arabic origin. Europeans also liked the astrolabe.

At one time, European craftsmen created similar devices, relying solely on the drawings of their Arab colleagues. A little later, they began to create their own models of the device, still using the drawings of oriental masters. Confirmation of this information is described in the treatises of Geoffrey Chaucer and the scientific works of Nikifor Grigoroi.

Popularity and design changes

The device's popularity peaked during the Renaissance. It was used during the astronomy education of students. At that time, gaining knowledge in the field of astronomy was a very prestigious matter. Moreover, every student was required to know how to use the treasured astrolabe.

At that time, European craftsmen paid a lot of attention to the artistic design of the device. Therefore, this item has become synonymous with talisman and antiques. Many wealthy people tried to purchase the device and add it to their collection of astrolabes. It was a matter of honor, spoke of excellent taste and indicated a high position in society.

And again modernization

Around the sixteenth century the device was again modified. According to European authors, the device long time was not finalized and was completely unadapted to European latitudes. It was more like a souvenir or a nice trinket, but not a compass or a valuable measuring instrument.

At that time, various scientists and other specialists were working on the astrolabe. Among them was the famous Flemish master Gualterus Arsenius. The products that he created literally amazed the imagination with their elegance of form and extraordinary accuracy of data. The master had no end to clients. Among them was the famous Austrian commander-in-chief Albrecht von Wallenstein. Currently, one of his collectible astrolabes is kept in the building of the M.V. Lomonosov Museum.

What parts does it consist of?

The main detail of the astrolabe is a rounded element with hanging rings to define the horizon lines and one high side. In common parlance it is called a “plate”. Inside such a circle there is a scale digitized in hours and degrees. Such markings are present along the entire perimeter of the “plate”.

Another flat disk of smaller diameter was usually placed inside the “plate”. They called it "tympanum". On its surface there are also notches, a scale, lines and points of the celestial sphere. And all of them are visible in stereographic projection. In the very center of this disk the celestial pole is marked; on the sides there are also circles of the great circle of the celestial sphere. There are also points of the southern and northern tropics, which serve as peculiar boundaries for the second disk.

On top of the second disc, or “tympanum,” is placed a small openwork lattice, called "spider". There are points on it that coincide with the location of the brightest stars in the sky. They can also be viewed in stereographic projection. This grid also has a special scale, the zodiac circle.

The device also holds several more data disks and is equipped with a hairsight or alidade. It has arrows and a rotary key that activates the device. All parts are attached to the main disk using a thin central axis.

Where was the astrolabe used?

The measurements obtained as a result of using this device were used in drawing up horoscopes, astronomy, mathematics, and physics. Some types of devices were modernized and played the role of a compass for sailors. Using this tool it was interesting to navigate in space and time. This is all an astrolabe.

A few words about stereographic projection

For the first time, one could hear about such a concept as stereographic projection from Claudius Ptolemy. It was he who described the process itself in his work called “Planispherium”. This is a three-dimensional image transferred to a sphere with one punctured point on a suitable plane.

Where can I find?

Today, the astrolabe can be purchased on virtual platforms and auctions, in souvenir shops, at flea markets and museums. It is difficult to make an astrolabe with your own hands. Here you need to understand mathematics, have experience in drawing and be able to correctly take the necessary measurements. After all, the veracity of the final result of the study will depend on how accurately the parameters are set on the device.

How to use an astrolabe?

To start working with the device, you need to pick it up. Using it you can measure the height of the Sun or one of the brightest stars. On final result, as a rule, indicates a ruler, or alidade. Then, the spider mesh rotates. In this case, the ecliptic points indicated on the device coincided with the image of the almucantarate (the smallest circle of the celestial sphere).

When correct use on front side device you will see a stereographic image of our sky. And then you can determine the current time and create an up-to-date horoscope.

What types of devices are there?

There are several varieties of this device. Among them, we highlight the following names of astrolabes:

  • Shuttle-shaped.
  • Perfect.
  • Universal.
  • Spherical.
  • Observant.
  • Linear.
  • Marine.

The shuttle-shaped device has a central and middle disk. The second largest circle depicts the ecliptic data and the meanings of the stars. The moving part of the device contains almucantarate and a horizon point.

The perfect device was invented by al-Saghani. Unlike other similar devices, when developing this one, a certain arbitrary mark in the celestial sphere was taken as the reporting point. The circles here contained conic sections and straight lines.

The universal device was created by al-Khojandi. As a point of reference, he took center point equinox. The spherical headset is presented in the form of a sphere. The linear astrolabe was invented by Sharaf ad-Din al-Tusi. This is a kind of rod with a scale and reticle. Finally, the naval device was developed in the 15th century. It is a kind of observation device. However, it is not at all intended to perform analog calculations.

This ancient instrument was created more than two thousand years ago, when people believed that the Earth was the center of the Universe. The astrolabe is sometimes called the very first computer. Undoubtedly, this is a device with the deepest mystery and beauty

The first astrolabe appeared in Ancient Greece. Vitruvius, in his writing “Ten Books on Architecture,” talking about an astronomical instrument called a “spider,” says that it was “invented by the astronomer Eudoxus, while others say Apollonius.” One of the main parts of this instrument was a drum, where the sky with the zodiac circle was drawn


Stereographic projection was described in the 2nd century AD. e. Claudius Ptolemy in his work “Planispherium”. However, Ptolemy himself called another instrument “astrolabon” - the armillary sphere. The final type of astrolabe was developed in the 4th century. n. e. Thus, in Alexandria, almost three hundred years after Ptolemy, the mathematician and philosopher Hypatia was condemned by Christian society for satanic rituals, including, among other things, the use of an astrolabe. She was beaten, raped and executed in 415 AD. Her student, Theon of Alexandria, left behind copies of notes on the use of the astrolabe.


After the death of Hypatia, Europe "lost" the astrolabe after the fall of the Roman Empire. Most ancient Greek knowledge was lost in Western Europe, whose population regarded ancient Greek (and therefore atheist) technology with great suspicion. However, it was carefully guarded by adherents of Islam; their use of the astrolabe is confirmed by many facts. Without Spain and its Islamic religion, the Renaissance would never have come. Most of the ancient Greek texts found have been translated into Arabic. They were later translated into Latin, and the astrolabe was then reintroduced to the vast majority of Europeans.


Scientists of the Islamic East improved the astrolabe and began to use it not only to determine the time and duration of day and night, but also to carry out some mathematical calculations and for astrological predictions. There are many works by medieval Islamic authors about various designs and uses of the astrolabe.
These are the books of al-Khorezmi, al-Astrulabi, az-Zarqali, as-Sijizi, al-Fargani, as-Sufi, al-Biruni, Nasir ad-Din at-Tusi and others.


Since the 12th century, astrolabes became known in Western Europe, where they first used Arabic instruments, and later began to make their own according to Arabic models. In the 16th century they began to be made based on their own calculations in order to be used in European latitudes.

The astrolabe reached its peak of popularity in Europe during the Renaissance, in the 15th-16th centuries; along with the armillary sphere, it was one of the main tools for astronomical education.

Knowledge of astronomy was considered the basis of education, and the ability to use an astrolabe was a matter of prestige and a sign of appropriate education. European craftsmen, like their Arab predecessors, paid great attention to artistic design, so that astrolabes became fashion items and collectibles at royal courts.


Modern encyclopedias say that this device is designed to determine the latitude of a place. In fact, the functions of the astrolabe are much more diverse: it can rightfully be called the computer of a medieval astronomer. Most likely, no one will be able to name the exact number of functions of the astrolabe, since different types of astrolabes could perform different types of work. Back in the 10th century, the Arab scholar al-Sufi wrote a detailed treatise consisting of 386 chapters, in which he listed 1000 ways to use the astrolabe. Perhaps he exaggerated slightly, but not by much. After all, with the help of this unique tool it was possible:

recalculate the ecliptic coordinates of stars or the Sun into horizontal ones (i.e. determine their altitudes and azimuths);
using observations of the stars and the Sun through a special viewfinder, determine the latitude of a place, directions to different cities (mainly to calculate the direction to Mecca), determine the time of day, determine sidereal time;
determine the moments of sunrise and sunset, i.e. the beginning and end of the day, as well as the moments of star rise, and if there were ephemerides, then of the planets; determine the ascending and setting degrees of the ecliptic, i.e. ascendant and descendant, build horoscope houses;

determine the latitude of an area by measuring the height of the Sun at noon or the heights of the stars at its climax (I’m not sure if this was done often, since using an astrolabe for this purpose is reminiscent of shooting sparrows from a cannon);
solve purely earthly problems, such as measuring the depth of a well or the height of an earthly object; and also calculate trigonometric functions (sines, cosines, tangents, cotangents).
make transformations between three coordinate systems - equatorial (right ascension and declination), ecliptic (longitude, latitude) and horizontal (azimuth, altitude), and much, much more...



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Published: April 25, 2011 at 01:05

This ancient instrument was invented more than two thousand years ago - in an era when people considered the Earth to be the center of the Universe. The astrolabe is often called the first computer, but no matter how controversial this statement may sound, there is no doubt that this instrument is surrounded by an aura of mystery and mystical beauty.

2. So what was the astrolabe intended for and how did it help our ancestors? Firstly, it made it possible to calculate quantities such as time based on the position of the sun and stars in the sky. Just like with a computer, you input information and the output is output. Typically, astrolabes were made of brass and were about 15 centimeters in diameter. But as you can see in the photographs, there were also larger specimens.

3. On the front side a starry sky was drawn, and on it were 20 of the brightest stars. The first question that comes to mind is: if the ancients believed that the Earth was at the center of the Universe, could these devices work correctly? After all, in fact, the Earth revolves around the Sun. Our ancestors, however, knew the relative sizes of the Earth and the Sun and the approximate distance between them. And based only on what we can see, between geo and heliocentric systems there is no difference, at least from a mathematical point of view.

4. The moving parts were installed opposite the divisions of the time of day and date, and the sky map corresponding to this moment was shown on the front side of the instrument. What's the point of this? With the help of the astrolabe, many astronomical problems were solved. The simplest is, of course, determining time. People could also calculate the time of sunrise and sunset. In addition, the device made it possible to determine the direction; so the astrolabe was an invaluable “compass” for Muslim scholars who were heading to Mecca.

5. Until the late Middle Ages, the astrolabe was one of the main instruments of astronomy. Over the centuries, many astrolabes have been invented, but the most common is the planispherical one, in which the celestial sphere is projected onto the plane of the equator. The principles of such a projection were discussed 150 years before the birth of Christ, however, it is believed that the first device was created much later. In fact, what we call the astrolabe was already in the service of astronomers by the year 400.

6. The astrolabe, like many other things, came from ancient Greece. It is known that the Greeks studied astrolabe projections two hundred years before our era. The theory was subsequently expounded by Hippocrates, who was born in Nicaea in Asia Minor. What is the connection with Greece? He conducted all his research on the island of Rhodes (Greece), where he wrote many works on trigonometry.

7. But when did the theory find physical embodiment? When was the first time a person picked up an astrolabe? The first mention of a device resembling an astrolabe is found in Marcus Vitruvius Polion, who died in 26 BC. He describes a clock in Alexandria that had a rotating disk depicting stars. Maybe this was the ancestor of the astrolabe?

8. Although there is no direct evidence for this, Claudius Ptolemy (died 168 AD) in his manuscripts (from his library in Alexandria) mentions a certain device very similar to the one we are talking about now. And since he wrote a lot about the geometry of the Earth-Sun system, which is the basis for the operation of the astrolabe, it would be fair to assume that he was also associated with its creation. Most astronomy historians consider the year 150 AD. date of appearance of the first astrolabe.

9. Times are changing. And now, three centuries later (and again in Alexandria), the Christian community of the city accuses Hypatia, a woman who studied mathematics and philosophy, of worshiping Satan. Among other objects for her “rituals,” an astrolabe is also mentioned... The crowd attacked her in broad daylight, she was raped and executed. This happened in 415 AD. Her student, Theon of Alexandria, left many records of the use of the astrolabe. However, its use in the West was banned for almost a thousand years.

10. It is interesting that after the death of Hypatia, the West finally lost the astrolabe when the Roman Empire fell, and the Dark Ages (formerly the Middle Ages) began for Europe. Much was lost from ancient Greek science to Western Europe. Its inhabitants began to treat Hellenistic - pagan - technologies with great suspicion. However, they survived in the Islamic world, where much evidence of their use and development has been found.

11. The Moors of Andalusia returned the astrolabe to Europe. Perhaps without the Spanish Arabs the Renaissance would never have come. To be fair, the knowledge of Arab Andalusia in the twelfth century spread throughout Europe. And many Western minds flocked to cities like Cordoba, which they considered centers of "lost knowledge." Greek texts, which could no longer be found in Europe, existed in such places in Arabic. There the books were translated into Latin, and the astrolabe was again presented to the European public.

12. And although these devices were replaced by more advanced instruments in the mid-seventeenth century, the astrolabe is still used to this day - mainly for teaching astronomy. And not only because it is of great historical value, it is also used for its intended purpose. And yet now the astrolabe, according to by and large, is a beautiful and mysterious instrument of ancient astronomers.