Why is astronomy the oldest science

Astronomy is more than simply a mapping of stars and planets into outlines of gods and magical creatures. Astronomers might ask themselves questions like: Is the Universe expanding, shrinking, or unchanging?

Does the Universe have a beginning? An end? Astronomy is one of the oldest sciences. Early cultures such as the Babylonians performed methodical observations of the night sky, and astronomical artifacts such as Stonehenge have been found from ancient times. However, the invention of the telescope was required before astronomy was able to develop into a modern science. They noted that the night sky looked different when seen from various locations on Earth, hinting at our planet's curved surface.

They also observed the round shadow of Earth on the Moon during lunar eclipses. These philosophers were even able to calculate the circumference of Earth quite accurately. They did this by measuring the length of the shadow cast by an object at exactly the same time, in two different locations. Taking into account the distance between those two locations and the difference in the lengths of the shadows, they calculated that Earth's circumference was about 46, kilometres.

That is very close to the real value of 40, kilometres! In the year , Chinese astronomers became the first to document a supernova. Several supernova explosions have been observed since then, including a particularly bright one in the year , which at its peak was four times brighter than planet Venus, one of the brightest objects in the night sky. Some supernovae are even bright enough to be visible during the day! The notion that our own galaxy — the Milky Way — is but one of trillions of other galaxies in the universe only dates back about a century.

Before then, nearby galaxies were thought to be cloudy regions of the Milky Way. The first documented observation of the neighbouring Andromeda Galaxy was in the year by a Persian astronomer who described it as a "nebulous smear.

The astrolabe, such as this one developed in by French clockmaker Jean Naze, is a navigational tool that can determine local time and location in latitude based on the position of celestial objects. Although the Sun is most commonly used, a total of 58 recognized "navigational stars" can help calculate the user's location.

One method of astronavigation even uses the angle of the Moon to calculate time, a key piece of information for pre-modern sailors travelling on unfamiliar seas. Credit: Marie-Lan Nguyen. Before the 16th century, Earth was commonly thought to be at the centre of the solar system, with all other celestial objects revolving around it. This is known as the geocentric model. This theory, however, did not match some confusing observations made by astronomers, such as the path of planets that appeared to move backwards on their orbits.