Evolution of Human Understanding of the Universe..? @shortknowingus

What did the ancient Greeks recognize as the universe? In their model, the universe contained Earth at the center, the Sun, the Moon, five planets, and a sphere to which all the stars were attached. This idea

held for many centuries until new ideas and better observing instruments allowed people to recognize that Earth is not the center of the universe.

Galileo's telescope revealed four moons orbiting Jupiter (not Earth) and many more stars than are visible to the naked eye. More importantly, Galileo's experiments established the principal of inertia which countered the physical arguments the Greeks used against a rotating and moving

Earth.

4th century BCE — Aristotle, building on the ideas of earlier astronomers, proposes that the Sun, Moon, planets, and stars revolve around a stationary Earth. This is known as the geocentric theory, meaning that the universe revolves around the earth.

2nd century AD — Ptolemy publishes a book that describes a mathematical procedure to calculate future positions of the Sun, Moon, and visible planets in the sky. It reaffirms that all these objects move

around a stationary Earth.

1543 — Nicolaus Copernicus publishes his heliocentric (Sun-centered) theory that proposes that Earth is a planet in motion around the Sun.

1610 — Johannes Kepler analyzed the accurate astronomical observations of Tycho Brahe, and discovers that the planets move around the Sun in elliptical orbits.

1687 — Sir Isaac Newton publishes the laws of motion and gravity that are used to accurately predict the motion of the Moon and planets.

1915 — Albert Einstein publishes the General Theory of Relativity, proposing that mass and energy cause space and time to curve or warp. This can be used to describe large-scale motion throughout the universe.

1929 — Edwin Hubble discovers a velocity-distance relationship for galaxies that implies that the universe is expanding.

In the early 20th century, an astronomer named Edwin Hubble (1889 –1953) (see Figure 1 below) discovered that what was then called the Andromeda Nebula was so far away that it had to be a separate

galaxy, outside our own Milky Way galaxy. Hubble realized that many of the objects that astronomers called nebulae were enormous collections of stars — what we now call galaxies.

In the early 20th century, an astronomer named Edwin Hubble (1889 –1953) (see Figure 1 below) discovered that what was then called the Andromeda Nebula was so far away that it had to be a separate galaxy, outside our own Milky Way galaxy. Hubble realized that many of the objects that astronomers called nebulae were enormous collections of stars — what we now call galaxies.

Hubble showed that the universe was much larger than our own galaxy.

Today, we estimate that the universe contains several hundred billion galaxies—about the same number of galaxies as there are stars in the Milky Way Galaxy.

#steven universe

#miss universe 2021

#coldest place in the universe

#nickelodeon universe

#miss universe

#marvel cinematic universe

#garnet steven universe

#dc universe

#steven universe characters

#how old is the universe

#student universe

#steven universe future

#the universe

#parallel universe

#cd universe