Across Space and Time Trivia Quiz

Ancient Babylonians studied the skies as they believed that celestial events were messages from the gods foretelling events concerning the state and the king. Therefore, they began keeping astronomical records. They were the first to recognize that celestial occurrences were periodic and could be predicted using mathematics. This moved astronomy into the realm of predictive science.

Greek, Hellenistic, Indian, and Islamic astronomers built directly upon Babylonian knowledge.The Babylonians also divided the sky into 12 equal sections called the zodiac which became a key aspect of Western astronomy and astrology.

In 150 AD, Ptoloemy wrote that Earth was stationary and at the center of the universe, with the Sun, Moon, planets, and stars revolving around it. In his text called "Almagest", he built his mathematical model on the prevailing Greek philosophical idea that all heavenly bodies must move in perfect circles. However, since he observed irregular paths of the planets (such as Venus), he proposed a system of circles within circles with more sphere-like shapes.

He stated that Earth was truly the physical center of the cosmos. All other celestial bodies, like the Moon, were thought to be attached to concentric spheres that rotated around Earth. He even lined them out from Earth as the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. This model created a practical method for calculating and predicting planetary positions, making it the standard for astronomers for the next thousand years.

Copernicus began a fundamental shift in scientific understanding by moving away from the long-held model of Earth being the center of the cosmos to a heliocentric model where the Sun is the center of the universe. He wrote a book called "On the Revolutions of the Heavenly Spheres" that was published in the year of his death in 1543 AD.

He put the Sun near the center of everything, with the Earth and other planets revolving around it. He explained that the Earth rotated daily on its axis. He also disputed that the other planets were moving "backward" saying it was simply an illusion caused by the Earth overtaking them in orbit. His work marked the beginning of an astronomical scientific revolution.

Brahe first observed the explosion of a star, in the constellation Cassiopeia, on November 11, 1572, while he was at Herrevad Abbey. Up until this point, scientists believed that the area past the Moon was unchanging and nothing like comets or meteors (which occurred between Earth and the Moon) happened out there.

Lacking a telescope (which had not yet been invented), Brahe observed this supernova for over a year. Using tools like a sextant, he postulated that the star was located much farther away, in the supposedly perfect and unchanging area beyond the Moon. His finding that the heavens were dynamic and subject to change was a key cornerstone for future astronomers.

After hearing of the invention of a telescope by the Dutch in 1609 AD, Galileo created his own version of the tool and began studying the planets through it. He published his findings in a 1610 AD text called "The Starry Messenger". First, he proved that celestial bodies were not unblemished spheres by noting the Moon's mountains and rough surface.

Next, he deduced that the "stars" around Jupiter were, in fact, moons (that would later be called Io, Europa, Ganymede, and Callisto). This proved that not all celestial bodies rotated around the Earth, but around other planets as well. He also showed that Venus orbited the sun (thus further proving the heliocentric model) and that the Sun changed with things like sunspots. He even suggested that the universe was much more vast than previously imagined.

In 1687 AD, Sir Isaac Newton created his work "Philosophiae Naturalis Principia Mathematica", often called just "Principia", which stated that the Earth, and the universe along with it, operated under a single, universal force called gravity. The central idea is that every object in the universe attracts every other object with a force that is proportional to their mass.

Before this time, people believed that scientific laws on Earth did not apply elsewhere. Newton proved that the same force that makes an apple fall to the ground (gravity) also keeps the Moon in orbit around Earth. He showed that the force of the Sun's gravity results in the planets' orbits. This also explained the ocean's tides due to the gravitational pull of the Moon.

German-born British astronomer Sir William Herschel discovered the planet Uranus on March 13, 1781 AD with a reflecting telescope. This finding proved there were more planets than just the five that were visible with the naked eye. One evening in 1781, while surveying faint stars from his garden, he noticed an object in the constellation of Gemini that appeared larger and different from the surrounding stars.

At first he thought it could be a comet but then he watched it move across the stars. He met with peers who calculated its circular orbit. All these characteristics confirmed that it was an undiscovered planet. He wanted to name it in honor of King George III, but went with Uranus to follow the naming convention of the other planets.

In 1912 AD, an American astronomer who worked at Harvard University made a critical breakthrough that would aid people to measure the scale of the universe. Henrietta Leavitt was studying Cepheids, which are stars that pulsate with regular, predictable changes in brightness. She determined that the longer the period of pulsation, the brighter the star. Astronomers could now use Cepheids as "standard candles".

By measuring the time it takes for a distant Cepheid to complete its light cycle, astronomers know its actual, intrinsic brightness. They can then compare this to how bright the star appears from Earth. This comparison then allows them to calculate the exact distance to the star and the galaxy it resides in, helping to map the scale of the universe.

In 1929 AD, Edwin Hubble, an American astronomer, published his landmark findings that the universe is not a static, single galaxy but is in fact constantly expanding. It started with two key observations. The first was that he saw, through an observatory, "spiral nebulae" (galaxies) outside the boundaries of the Milky Way. Then, by measuring their velocities, he showed that the galaxies were moving rapidly away from Earth.

This helped create Hubble's Law which is that the farther away a galaxy is, the faster it is moving away from us. This proof that the universe expands would be the foundation for the Big Bang Theory that the universe started from a single, incredibly dense point in the distant past.

American astronauts landed on the Moon on July 20, 1969. This event brought a new era of research, transforming the Moon from a distant object of observation into a true physical laboratory. Lunar rock samples were brought back and scientists were able to establish the Moon's age at around 4.5 billion years old and calibrate a timeline for the entire inner solar system. Analysis at the time also revealed that the Moon was dry and lifeless.

The astronauts also did experiments on the Moon's surface itself. They left an array of mirrors that work with laser beams "shot" from Earth to measure the Moon's distances. A seismometer recorded moonquakes and meteoroid impacts. Also, samples of solar wind particles were collected which were returned to Earth for analysis of their composition. This provided data on the variations in the Sun's output over time.