The Big Bang

The event where the universe was born starting at one small point. Before the big bang, there was absolutely nothing: there was no time, space, matter, or energy of any type. Then out of nowhere, all the matter and energy that make our universe came out of one single point, about 13.7 billion years ago. Then after that, the universe continued to expand. , stars and galaxies formed. The universe is still expanding.

Stonehenge 3100 BC

They are stones about 4 meters high, and they were an early sign of ancient civilizations understanding the patterns of the sun. They made astronomical alignment with the stones, which means the sun would shine through the heelstone on summer solstice.

Aristotle- 385 bc

He was an influential greek Philosopher that was listened too and well respected back in his day. He realized the moon had phases and went around the earth. He thought that the moon is closer than the sun. And he thought that earth was round. He also though that the earth was the center of the universe.

Eratosthenes 276 BC

He was a greek Mathematician, Astronomer, and geographer. He was the first person to calculate the circumference of the earth. He compared the altitudes of the midday sun and two different spots, and he was very accurate. He was the first to calculate the tilt on the earths axis, and he calculated the distance between the earth and the sun.

Aristarchus-310-230 BC

He was a greek astronomer/mathematician. He was the first to suggest that the sun was in the center of the universe. He used geometry to try to find the distance from the sun to the earth.

Hipparchus- 190 BC to 120 BC

He developed a system for describing a star's position and brightness. He also was the first to discover that the world had a wobble.

Ptolemy- 85-164 AD

He tried to explain retrograde motion hypothesising that some planet seem to be moving backwards in the sky is because he thought that the planets had a little orbit going around a point, as they orbited the earth. He was a geocentric believer. His theory is wrong, and he is known as being the wrongest for the longest time.

Nicholas Copernicus- 1473-1543

He was a german Mathematician and astronomer. He thought that the sun was in the middle of the universe rather than the earth. He made a model of the universe that had the sun in the middle.

Tycho Brahe- 1546-1601

He is best known for his observations in astronomy. He developed the Tychonic cosmological model. He discovered the variation of the moons longitude.

Galileo Galilei- 1564-1642

He is best known for changing science from being a bunch of philosophy to being modern science. He was the first astronomer to be using a telescope, which was revolutionary in astronomy. With his telescopes, he made many good observations in the universe, and he discovered other planet's moons too. He did many observations on the planets.