Galactic Years and Celestial Concepts

The video explores the concept of a year, defining it as the time it takes for one body to orbit another. It discusses different types of years on Earth, such as tropical, sidereal, and anomalistic years, and explains how our civil calendar aligns with the tropical year. The video also covers non-Earth years, including those of Mercury, Neptune, and the Galactic year. It highlights the orbits of stars around the Milky Way's supermassive black hole and credits the UCLA Galactic Center for their research.

What is the basic definition of a year?

• The time it takes for the Moon to orbit the Earth.

• The time it takes for the Earth to rotate once on its axis.

• The period it takes for one body to orbit another.

• The duration of a single season on Earth.

Which type of year is defined by the Earth's axis returning to the same angle relative to the sun?

• Sidereal year

• Anomalistic year

• Tropical year

• Galactic year

What is a sidereal year?

• The time it takes for the Earth to complete one orbit around the sun.

• The time it takes for the same stars to rise behind the sun again.

• The time between closest approaches to the sun.

• The time it takes for the Earth to rotate once on its axis.

Which year does the civil calendar attempt to follow?

• Galactic year

• Tropical year

• Sidereal year

• Anomalistic year

How long is a year on Mercury in Earth days?

• 88 Earth days

• 225 Earth days

• 365 Earth days

• 165 Earth days

What is the approximate duration of a Galactic year?

• 88 Earth years

• Ten Earth years

• 165 Earth years

• A quarter of a billion Earth years

What is the significance of the orbits of stars around the supermassive black hole at the center of the Milky Way?

• They determine the length of a Galactic year.

• They help measure the size of the Milky Way.

• They indicate the presence of a black hole.

• They show the age of the Milky Way.

How massive is the supermassive black hole at the center of the Milky Way compared to the sun?

• As massive as 1 million suns

• As massive as 2 million suns

• As massive as 3 million suns

• As massive as 4 million suns

Where can you learn more about leap years on Earth?

• The Keck telescope website

• Grey's channel, 'cgpgrey'

• NASA's website

• The UCLA Galactic Center