Clay was used as the bonding material by Babylonians and Assyrians. Later, clay was replaced by gypsum and lime by Egyptians. First modern concrete was invented by a British engineer named John Smeaton in the year 1756. He created the concrete by adding pebbles and powdered brick with cement.

Followed by the modern concrete, in the year 1824, Joseph Aspdin from England invented the Portland cement. Portland cement is considered the dominant cement that is being used in construction.

The other type of concrete called reinforced concrete was developed with imbedded metal like steel and it was introduced by Joseph Monier in the year 1849. But he received the patent rights only in the year 1867. Reinforced concretes were used in pipes, floors, railway ties and bridges.

Barcodes were invented by Joseph Woodland and Bernard Silver. They have received the first patent for bar code type product in the year 1952. Bar code invented by them was referred to as ‘bull’s eye’ symbol which were made up of a series of concentric circles.

It is a simple and effective way to identify the products. A bar code consists of 12 digits. The first two digits point out the country of origin. The next four digits indicate the manufactures and the remaining six digits refer to manufacturer and the product code of a specific product. Each number or character in the bar is represented by two black stripes and two white stripes.

In 1977 George J. Laurer, availed the credit of inventing the widely used bar code UPC system – Universal Product Code.

Lucien B. Smith from Ohio received the first patent right for invention of barbed wire in the year 1867. Later, Joseph F. Glidden, Illinois received the patent rights in the year 1874 for the invention of modern version of barbed wire. This was the development of the same with modern techniques and improvements.

A person or an animal may suffer discomfort or may get injured while passing the wired fence. Barbed wire fences made it possible for farmers to protect their farms from roaming cattle and allowed them to erect a simple and cost effect barrier that could demarcate the edges of their property. It requires fence posts, wire and fixing devices like staples or tapes and can be erected by even an unskilled person. The fencing wire is inexpensive and easy to erect when compared to other alternatives. Additionally the barbed wire is also used to divide Israel from other Palestinian territories. It also delimits the refugee camps in following areas like Jordan, Lebanon and Syria.

Modern alphabets were derived from the idea developed by ancient Egyptians. But the pictures were simplified to represent the sounds of consonants. These pictures were simplified by Phoenicians.

The major problem was, all letters were consonants that was logical for Semitic languages namely Hebrew, Phoenician, Arabic. But Greek required extra sounds in form of vowels in their alphabets. They removed few consonants and replaced these with vowels to represent the extra sound as required by them. The unused letters were retained by Greek in their numbering system.

Greeks followed the system of writing from right side to left side, which is still being followed in Arabian countries.  But gradually they are changing their ancient writing method to the present system of left to right. They have passed this habit to all European countries.

Alphabets being used in South Asia and Southeast Asia have been derived from Brahmi alphabet system, which was based on Aramiac. The phonetic order of the present system of alphabets has been created by Indians.

Constellation Aries according to Greek mythology

The most popular story about how Constellation Aries began is that of Phrinux and Helle.  Athamas, king of Poitia, and his wife Nephele had a son and daughter. The son was named Phrixus, the daughter Helle. Years later Athamas married a second wife named Ino. But Ino fell in love with Phrixus, who did not like her in return. Ino got so hurt by the rejection that she schemed to kill brother and sister. She planned to starve them to death. But Nephele sent a magical ram to rescue them. Phrixus survived, but Helle drowned during the rescue. Upon reaching home, the magic ram told Phrixus to offer him to the Gods. The boy obeyed and the ram found a place among the stars.

The Stars in the Constellation Aries

There are seven star clusters that make up Constellation Aries: Alpha Arietis, Gamma Arietis, Beta Arietis, Lambda Arietis, Pi Arietis, 30 Arietis, and 53 Arietis. They form the points that give the constellation a ram shape.

Alpha Arietis (or Hamal) is the brightest of them all. It is red and 50 times brighter and bigger than the sun. Gamma Arietis is made up of two stars. It is blue. Beta Arietis is smaller than Gamma Arietis and is 60 light years away. Lambda Arietis is further still at 133 light years away.  Pi Arietis is also a double star. It has a bluish tint.

Meanwhile 30 Arietis is very visible. It has a magnitude of 6.6. It is yellow. There is another star near it with a magnitude of 7.4. 53 Arietis is made up of  three stars that turn very fast. Experts believe 53 Arietis is part of a supernova.

Meteor showers in the Constellation Aries

There is small galaxy about 5.3 arc-minutes across Constellation Aries. It is believed to be a spiral galaxy. There are also a number of meteor showers around the constellation. One curious meter shower is called May Arietids. It occurs between May and June. Unlike most meter showers May Arietids happens during the day.

The two other visible showers are Epsilon Arietids and the Delta Arietids. The rest are too difficult to see.

Recent findings

Recently it has been proved that some of Constellation Aries’s stars have planets. A number of  new galaxies have also been discovered. Some of them are NGC 772, NGC 972, and NGC 1156.  They cannot be seen by the naked eye.

Constellation Aries is a spellbinding sight in the sky. According to astrology, people born under the sign of Aries are bold and optimistic.

Clusters of  Gemini

Gemini means “twins” in Latin. It is a constellation named after the twins Castor and Pollux in Greek mythology. The constellation is found between Taurus and Cancer. To its north are Lynx and Auriga, to the south Monoceros and Canis Minor.  Constellation Gemini has a cluster called Open Cluster M35. Northeast of Gemini is another cluster of nebula called NGC 2371. Gemini’s southern tip has Abell 21, otherwise known as the Medusa Nebula.

Gemini took its name from legendary characters in Greek mythology. Since it is a constellation, no one knows for sure who saw it first. Stars clusters have been up in the sky for the longest time.

The myth behind Gemini

According to popular myth, Castor and Pollux, were known together as the Dioscuri.  Their story involved cattle theft. As such, the story was used as a symbol for the Milky Way as a herd of cows. When seen in astronomical maps, Gemini tended to lean away from the Milky Way. At times they are seen with one of the twins within the Milky Way, the other outside. So it appears as though Castor is taking the cattle while Pollux looks on. The story of Gemini is said to have given rise to the myth of the cows of Geryon.

Earliest Observers of Gemini

As early as 6000 years ago the Hindu history book called the Rig Veda already described the stars of Gemini. The Rig Veda called Gemini’s stars as the twin horsemen of the dawn. In ancient India Gemini’s stars were known as Nakula and Sahadeva. These two stars could be clearly seen at dawn in spring. This led to the belief that the twin stars meant the coming of the spring equinox. In ancient India Gemini meant Mithuna, the twins. So the old Western and Eastern meanings were one and the same.

The teachings of ancient India spread westwards to the Far East around 5000 BC. It caught on in Babylon as it did in the rest of the Middle East. Babylonians adopted Indian astronomy to keep track of the seasons for sea travel. Ancient Babylonians called Gemini as Mastabba Galgal, which meant the great twins. But the Babylonains put a spin to it: They came up with their own epic whose heroes were twins Gilgamesh and Enkidu. The great twins fought the gods in search of immortality.

Gemini in ancient Egypt and Greece

Ancient Egypt’s version took the form of twin goats which stood for the two stars told about in the Ramissede Hour Tables. The Ramissede was a book that told time through the position of stars in the night sky. Ancient Egyptians had observed that the two stars of Gemini did rise and follow each other at dawn.

Around 1000 BC, the Greeks picked up on that as well. The Greeks borrowed freely from ancient Babylonian and Egyptian astronomy. Perhaps they were a little more creative in that they embellished the stories behind the constellations with human drama.

When the Romans invaded Greece, the vicious cycle of lifting and borrowing went on. The Romans changed Polydeuces’s name to Pollux. But it came to a point where Gemini took on a single status because either one of the old names went missing for some time.

Gemini to according to sailors

Today, folk sailors still believe Castor and Pollux guide their ships and point their way back. In times of danger, Castor and Pollux send St. Elmo’s fire to signal an oncoming   bad luck.

One of Sagittarius’s most spectral sights is the Lagoon Nebula (M8). It is considered a diffuse nebula: In the sky they look like scattered gold dusts.   Lagoon Nebula was discovered by Le Gentil in 1747.

Earliest sightings of Sagittarius

Ancient Babylonians referred to Sagittarius as Pabilsag or Nergal, a god with wings and the head of a lion.  The Greeks pictured Sagittarius as a centaur, a creature that was half horse, half human.

According to a popular Roman legend at the time, Chiron was a centaur who was the son of Saturn and Philyra. Saturn changed himself into a horse to break free from his very possessive wife, Rhea.

Being the son of a god, Chiron was born very smart. He was exceptionally good at hunting, poetry, music, war, medicine, and the study of the stars. Chiron taught young Greeks in a cave beside the mountain.  His pupils observed him to be quiet and reserved. He seemed to be aloof and lost in his thoughts most of the time. He was never known to have a girlfriend.

Now one of his pupils was Hercules. Hercules would come to the came even when there was no class. He liked to talk for a bit with his teacher long after classes were finished. On one such occasion, and with wine to go with the talk, a pack of drunk centaurs attacked student and teacher.  In the wild scramble one of Hercules’s poisoned narrows scraped Chiron by the arms. The arrow’s poison was made from the blood of Hydra. Chiron was immortal, therefore he could not die. But he could not endure the poison’s pain.

To relieve himself, he gave up his immortality in exchange for Prometheus’s freedom from torture. Zeus, the supreme god, took the offer with much respect for Chiron. In the end instead of leaving Chiron in Tartarus as agreed, Zeus placed him in the sky as constellation Sagittarius.
When you look at the southern hemisphere skies between June and July, Sagittarius outshines the rest of the constellations. At the height if the winter solstice the sun appears in Sagittarius.

Sagittarius according to the Greeks

The ancient Greeks told of the story of Crotus, a satyr that lived with the muses on Mount Helicon. Crotus played music and sang in the choir. He was the inventor of clapping at the end of a play and music. Crotus always did that with perfect timing and with such flourish that he endeared himself to the Muses. When Crotus died, the Muses entreated Zeus to honor the great clapper by placing him up in the heavens. Zeus made a constellation of a centaur instead of a satyr, recognizing Crotus’ other skill as a great rider.

In some quarters today, there is still confusion about whether Sagittarius was Chiron or Crotus.  It is more likely that the Romans tweaked the story. Ancient historians like Ovid, Hyginus, and Diorosos concurred that Chiron was a Centaur and not a satyr.

People born under constellation Sagittarius

Sagittarians are known to be very optimistic. As such they are full of energy.  They also love adventure and travel.

On the other hand, farmers read the stars to prepare for a good or bad harvest. This lead to planting and harvesting seasons. In parts of the world where different constellations appeared in different seasons, they used the stars to tell the month instead. For instance, constellation Scorpius can be seen only in northern hemisphere skies in summer.

For the record

The oldest record of star-gazing was found in Sumerian board games around 4000 BC. Sumerians named the stars after their gods. Early Chinese constellation had much in common with Middle Eastern and Western constellation.  The Babylonians had divided the zodiac into 12 signs by 450 BC. The present constellation is largely based on Egyptian astrology. The Greeks named 48 constellations.

Constellation controversy

By the end of the 16^th Century European seafarers drew maps of the austral hemisphere.  Pieter Dirckz Keyser added a few more constellations while on board a ship to the East Indies in 1595.   His version was added to Johann Bayer’s, a German cartographer who published an atlas of Europe. More European experts offered new constellations such as the French Nicolas Louis. The International Astronomy Union fixed the number of constellations to 88.

The 12 constellations on the ecliptic side were called as the Zodiacs. Twenty-nine constellations lie between the North Celestial Pole and the ecliptic. The constellation Ophiuchus is part of the ecliptic side. The remaining 47 constellations are found between the South Celestial Pole and the ecliptic side.

Constellations today

Many of the old constellations have been changed. Their positions have been fixed in the sky. Of the 88 constellations, three animals appear twice: Pisces/Pisces Austrinus, Ursa Major/Ursa Minor,  and Canis Major/Canis Minor. The northern hemisphere constellations have not changed for the last 2000 years.

How do you know you are looking at Leo? You are supposed to see a crouching lion that looks to the west. You should see the head and mane clearly, above which hangs a sickle of stars.  If the sickle is not sharp enough, you should see an inverted question mark at least.

Leo’s brightest star is Regulus. It is found south of the pointy stars of the Big Dipper, northwest of Virgo. Leo shines brightest on or around March 1.

Leo in ancient Egypt

The figure of a lion has been associated with the sun since the earliest times. Belief in the lion as symbol of the sun began in ancient Persia. More than 5000 years ago, the sun “passed over” Persia and Egypt at the height of the midsummer solstice. From then on Leo was lumped in with the coming of high summer. Leo’s time was poetically called “the realm of the sun”.  On closer inspection, you cannot miss the Sphinx’s body, which is that of a lion.

Even in ancient Africa, the lion stood for strength and power. It is no king of the beasts for nothing.

Leo in the story of Pyramus and Thisbe

According to Roman mythology, Leo was the symbol of the Nemean lion, one of Hercules’s greatest fights. Hercules was tasked to skin a gigantic lion whose hide did not even bruise against metal and stone.  Being a demigod, Hercules managed to pin down the lion with his bare hands. He choked the lion to death and skinned it with the use of its own claws. The hero took home the hide as his trophy, but not without turning it into an invincible cloak. The lion’s head he made into a helmet.

To the ancient Greeks, the Leo figured in the love story of Pyramus and Thisbe. Ovid’s Metamorphosis recounts of how Pyramus and Thisbe’s parents objected to their romance. Sounds like Romeo and Juliet? It must have been one of the ancient sources. What the two-star-crossed lovers did was talk through a tiny hole in the wall that divided their houses. One day they hatched a plan to meet far outside the city. It had to be right next to a mulberry tree. When the day came, Thisbe came all by herself. Pyramus was nowhere in sight. She waited for some time and soon enough a lion fresh from a kill strayed by.

Thisbe ran for her life. She was just quick enough to get her body out of the lion’s way. Instead the lion snapped and pawed at a piece of her veil. Pyramus arrived late to see Thisbe’s veil in bloody pieces. He instantly thought Thisbe was mauled dead by the lion. He pulled his sword and drove it deep into his body. Pyramus did not think twice to kill himself to be with his love. Thisbe came back and saw her dead Pyramus. She threw herself on Pyramus, cried hard, and thrust the bloodied sword into her body. The lovers’ blood soaked into the white mulberry flowers. And the deep red color stayed ever since. The supreme god Zeus hung Thisbe’s veil up in the sky, with the lion just above it.  The veil was later known as Coma Berencies.

Leo in ancient Middle East

Leo’s moon, Regulus, got its name from Copernicus. The name originally meant “the little king.” The ancient Sumerians called  Regulus as the “star of the king.” In ancient Persia and Iraq, Regulus was called “the flame” or “red fire.” They associated red fire with the onset of an extremely hot summer. Ancient Persians considered  Regulus  one of the four royal stars:  The other royal stars were Fomalhaut, Aldebaran, and  Antares.

By 2300 BC ancient astronomers in the Middle East had observed that the sun moved in near Regulus. As it did, the summer grew hotter and hotter. The ancients gave this role to Sirius at a later time.

Meanwhile, the stars of Leo formed a horse in  ancient Chinese zodiac.

Leo’s stars

Two of leo’s famous stars are Algiebra and Wolf 359. Algivebra is  abinary system (meaning a pair). The brighter one looks like giant orange, right next to a giant ripe lemon (the smaller pair).

Wolf 359, on the other hand, the least visible of Leo’s stars, in spite of being popular. It was discovered by Max Wolf in 1918.

It is said the quadratic formula has been used and known by man for thousands of years. The equation has changed a number of times, too.

Some 2000 years ago, the Chinese, Babylonians, and Egyptians already knew the area of a square  levels with the length of its sides. Using bales of hay, they figured they could stack nine bales more if the roof space were three times wider.  The Chinese, Babylonians, and Egyptians could compute the area of other complex shapes.

But they did not know how to work out the sides of those shapes. And so they were faced with a bigger problem: They had to be able to calculate the length of the sides starting from a certain point. The shape should be leveled with a total area using the lengths of the sides.

How the Egyptians used the quadratic formula

1, 500 years ago, the Egyptians did not use numbers like we do today. They expressed mathematical problems using words. But Egyptian scribes skirted the quadratic equation issue by solving the area of all sides and made a reference chart. They made up something like a multiplication table.  That made computation fast and quick. Egyptian engineers did have to compute all shapes and sides all the time. All they had to do was look at the chart.

Up this day these tables till exist. They may not be mathematically correct, but they certainly show how the quadratic formula began.   .

How the Babylonians used the quadratic formula

The Babylonians had a different way of solving the problem. Unlike the Egyptians, the Babylonians used numbers instead of words. The Babylonians numbers were pretty much the same as the numbers we use today, except that theirs were based on a hexagesimal model (or base 60). With this system multiplication and addition were easier to do. So around 1000 BC Babylonian engineers could check whether the values of their tables were right or wrong.  The Babylonians came up with a technique called “completing the square” to solve common problems with areas by 400 BC.

Euclid and Pythagoras

The first purely mathematical try to come up with a quadratic formula was done by Pythagoras in 500 BC. Euclid did the same thing in Alexandria, Egypt. Euclid used a purely geometric method. And he came up with a general formula to solve the equation. For his part Pythagoras observed that the ratios between the area of a square and the length of the sides did not add up. To him there was no other proportion except the rational. Euclid thought otherwise: If there are rational numbers, there must be irrational numbers.  He then wrote a book called Elements in which he lay down the mathematics of solving quadratic equation.

But Euclid’s equation did not use the same formula that we know today. His formula could not compute the square root of any number by longhand.

How Hindu mathematicians added 0 to the equation

The Hindus are credited to have created the concept of 0, for nothingness. Western mathematicians could bring themselves to believe in the value of nothing. The Hindus, on the other hand, believed in “shunya” , meaning the void, or a state of equilibrium.

By 700 AD, a Hindu mathematician named Brahmagupta was using irrational numbers. He came up with two roots in the answer. But around 1100 AD,  another Hindu math wizard, Baskhara, discovered that any positive number has two square roots.

How the quadratic equation spread to Europe

Mohammad bin Al-Khwarismi, a respected Muslim mathematician in Baghdad was able to solve the quadratic equation in 820 AD. He did not use numbers nor negative solutions. Word got around about what he did. So a Jewish mathematician named Abraham bar Hiyya brought this piece of knowledge to Barcelona, Spain in 1100.

From then on mathematicians all over Europe picked up and used the equation.