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The construction of Stonehenge started in 3000 BC. Although there are many mysteries relating to this work, one of the theories is that it was built by ancient astronomers, who used the giant stones to predict eclipses of the moon and sun.

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Hipparchus was born at around 190 BC, in Nicea, Greece. For starters, Hipparchus measured the distance between the Earth  and moon correctly, using trigonometry. He also observed a nova, as well as equinoxes. Hipparchus  also studied the eclipses, as well as the Earth's precession.

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Claudius Ptolemy was born in 100 AD in Alexandria, Egypt. Contrary to what Copernicus believed, Ptolemy believed that the Earth was at th center of the Universe, and that the planets, sun, moon and stars orbited around it. This became known as the "geocentric theory". This theory was later on disproved.

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Nicolaus Copernicus was born in February 19, 1473 in Torun, Poland. He proposed that Earth, as well as  other planets, revolved around the sun.However, his theory was that the sun was stationary, as it was in the center of the universo. Although he was right about planets revolving around the sun, he  was brong about the sun being tsationary, for it rotates as well. He was also wront about the sun being in the center of the universe.

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Brahe was born in December 14, 1546 in Denmark. Like many other astronomers before him, Tycho Brahe believed in geocentricism. However, he influenced astronomy a lot because he created many  astronomical instruments such as the Tyonian Quadrant, which was used to locate astronomical objects, according to where they were on the quadrant at the time. Brahe was this, along with making some of the most accurate findings of planetary positions, some of which we still use today.

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The famous astronomer, Galileo Galilei was born on February 15 of 1564 in Pisa, Italy. He invented a telescope and used it to discover dour of Jupiter's moons. He also used this telescope to study Saturn, and used these observations to support Copernicus' theory that the planets all revolve around the sun. Galileo also studied the sunspots, and the phases of Venus.

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Who was Galileo Galilei?

Galileo was born in Pisa, Italy on 15 February 1564 (Julian calendar; 26 February 1564 by our modern day Gregorian calendar), the first of six children.

Prior to Galileo's conflict with the Church, the majority of educated people in the Christian world subscribed either to the Aristotelian geocentric view that the earth was the center of the universe and that all heavenly bodies revolved around the Earth, or the Tychonic system that blended geocentrism with heliocentrism.

His championship of the Copernican (Sun-centred) planetary system brought him into serious conflict with the Church, which forced him to make a public recantation and put him under restriction in later life.

What is Galileo most famous for?

Galileo, though not the first inventor of the refracting telescope, significantly enhanced its power. In 1609, he learned of the spyglass and began to experiment with telescope-making, grinding and polishing his own lenses. His telescope allowed him to see with a magnification of eight or nine times, making it possible to see that the Moon had mountains and that Jupiter had satellites.

What did Galileo discover?

Galileo used observation and experimentation to interrogate and challenge received wisdom and traditional ideas. For him it wasn't enough that people in authority had been saying that something was true for centuries, he wanted to test these ideas and compare them to the evidence. At the time this was quite a shocking idea, and was one of the reasons that he got into trouble. He discovered...

1. Craters and mountains on the Moon

The Moon's surface was not smooth and perfect as received wisdom had claimed but rough, with mountains and craters whose shadows changed with the position of the Sun. Galileo was able to use the length of the shadows to estimate the height of the lunar mountains, showing that they were similar to mountains on Earth.

2. The phases of Venus

The planet Venus showed changing crescent phases like those of the Moon, but their geometry could only be explained if Venus was moving around the Sun rather than the Earth. This undermined the idea that everything in the heavens revolved around the Earth (although it was consistent with the Tychonic system as well as the Copernican one).

3. Jupiter's moons

The planet Jupiter was accompanied by four tiny satellites which moved around it. These are now known as the Galilean moons: Io, Ganymede, Europa and Callisto. Again, this showed that not everything in the heavens revolved around the Earth.

4. The stars of the Milky Way

Galileo saw that the Milky Way was not just a band of misty light, it was made up of thousands of individual stars.

5. The first pendulum clock

If that wasn't enough, as well as Galileo's contributions to astronomy, he also designed a major component for the first pendulum clock, Galileo's escapement. This design, however, went unbuilt until after the construction of the first working pendulum clock by Christiaan Huygens.

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Galileo was born in Pisa, Italy on 15 February 1564 (Julian calendar; 26 February 1564 by our modern day Gregorian calendar), the first of six children.

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Johannes Kepler was born in December 27 of 1571 in Germany. He is notorious for his three laws of planetary motion. Kepler discovered that the planets, as well as the Earth, traveled around the sun in specific orbits.

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Orbits and Kepler’s Laws | NASA Solar System Exploration

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Explore the process that Johannes Kepler undertook when he formulated his three laws of planetary motion.

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Isaac Newton was born in December 25, 1642, in Woolsthorpe Manor House, U.K. He shaped the word today for not only inventing the laws of motion and gravity, but also for inventing calculus, which is used in astronomy. Newton was also one of the very first to create a reflecting telescope. This, along with his three Laws of Motion, lay an important foundation for the understanding of universal gravitation.

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In March 14 of  1879, Albert Einstein was born. He devised a theory and named it relativity. IN short, this theory supported the notion that space and time were linked together, and that the universe had a speed limit. This was because he concluded that nothing would be able to travel faster than the speed of light, which is 186,000 miles per second.  Aside from this, he created an equation used for physics, which to this day is still used to help astronomers study the gravitational waves in Mercury's orbit.

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Childhood and education

Einstein's parents were secular, middle-class Jews. His father, Hermann Einstein, was originally a featherbed salesman and later ran an electrochemical factory with moderate success. His mother, the former Pauline Koch, ran the family household. He had one sister, Maria (who went by the name Maja), born two years after Albert.

Einstein would write that two "wonders" deeply affected his early years. The first was his encounter with a compass at age five. He was mystified that invisible forces could deflect the needle. This would lead to a lifelong fascination with invisible forces. The second wonder came at age 12 when he discovered a book of geometry, which he devoured, calling it his "sacred little geometry book."

Einstein became deeply religious at age 12, even composing several songs in praise of God and chanting religious songs on the way to school. This began to change, however, after he read science books that contradicted his religious beliefs. This challenge to established authority left a deep and lasting impression. At the Luitpold Gymnasium, Einstein often felt out of place and victimized by a Prussian-style educational system that seemed to stifle originality and creativity. One teacher even told him that he would never amount to anything.

Yet another important influence on Einstein was a young medical student, Max Talmud (later Max Talmey), who often had dinner at the Einstein home. Talmud became an informal tutor, introducing Einstein to higher mathematics and philosophy. A pivotal turning point occurred when Einstein was 16 years old. Talmud had earlier introduced him to a children's science series by Aaron Bernstein, Naturwissenschaftliche Volksbucher (1867-68; Popular Books on Physical Science), in which the author imagined riding alongside electricity that was traveling inside a telegraph wire. Einstein then asked himself the question that would dominate his thinking for the next 10 years: What would a light beam look like if you could run alongside it? If light were a wave, then the light beam should appear stationary, like a frozen wave. Even as a child, though, he knew that stationary light waves had never been seen, so there was a paradox. Einstein also wrote his first "scientific paper" at that time ("The Investigation of the State of Aether in Magnetic Fields").

Einstein's education was disrupted by his father's repeated failures at business. In 1894, after his company failed to get an important contract to electrify the city of Munich, Hermann Einstein moved to Milan to work with a relative. Einstein was left at a boardinghouse in Munich and expected to finish his education. Alone, miserable, and repelled by the looming prospect of military duty when he turned 16, Einstein ran away six months later and landed on the doorstep of his surprised parents. His parents realized the enormous problems that he faced as a school dropout and draft dodger with no employable skills. His prospects did not look promising.

Fortunately, Einstein could apply directly to the Eidgenössische Polytechnische Schule ("Swiss Federal Polytechnic School"; in 1911, following expansion in 1909 to full university status, it was renamed the Eidgenössische Technische Hochschule, or "Swiss Federal Institute of Technology") in Zürich without the equivalent of a high school diploma if he passed its stiff entrance examinations. His marks showed that he excelled in mathematics and physics, but he failed at French, chemistry, and biology. Because of his exceptional math scores, he was allowed into the polytechnic on the condition that he first finish his formal schooling. He went to a special high school run by Jost Winteler in Aarau, Switzerland, and graduated in 1896. He also renounced his German citizenship at that time. (He was stateless until 1901, when he was granted Swiss citizenship.) He became lifelong friends with the Winteler family, with whom he had been boarding. (Winteler's daughter, Marie, was Einstein's first love; Einstein's sister, Maja, would eventually marry Winteler's son Paul; and his close friend Michele Besso would marry their eldest daughter, Anna.)

Einstein would recall that his years in Zürich were some of the happiest years of his life. He met many students who would become loyal friends, such as Marcel Grossmann, a mathematician, and Besso, with whom he enjoyed lengthy conversations about space and time. He also met his future wife, Mileva Maric, a fellow physics student from Serbia.

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Albert Einstein | Biography, Education, Discoveries, & Facts

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Albert Einstein, the brilliant physicist and Nobel laureate, revolutionized our understanding of the universe with his theory of relativity and became a symbol of genius that continues to inspire minds worldwide.

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In oxford, England of January 8, 1942, a great mind was born.  The man with this great mind was named Stephen Hawking. Although dealing with medical conditions, Hawking made his discovery of black holes, and the radiation it had, which could be detected by an instrument. This radiation is known as the Hawking radiation, and nothing can escape from it.