Time & Astronomy
This is the reason we have day and night on Earth.
Earth’s rotation.
This ancient civilization is credited with inventing the first mechanical clocks.
→ The Chinese.
According to Einstein, this happens to time when you move very fast.
→ Time slows down (time dilation).
This is the smallest unit of time in common physics.
→ The Planck time.
Planck time = the smallest possible unit of time.
Below this, time doesn’t make sense according to current physics.
1. Definition Planck time is the shortest time interval that has physical meaning according to our current understanding of the universe.
It is the time it takes for light to travel one Planck length, the smallest possible distance.2. How small is it?1 Planck time ≈
0.0000000000000000000000000000000000000000001 seconds
(or 10⁻⁴³ seconds) That is 1 divided by 10 with 43 zeros — unbelievably tiny.
This country has the most time zones in the world.
→ France (12 time zones including territories).
Earth completes one full orbit around the Sun in this amount of time.
→ 1 year (about 365.25 days).
Before clocks, ancient people used these devices that measure time with shadows.
→ Sundials.
The international standard for world time is known as this.
→ UTC — Coordinated Universal Time.
The number of seconds in a minute was defined by this ancient culture.
→ The Babylonians.
This is the only continent that crosses all time zones.
→ Antarctica.
This is the shortest unit of time ever measured.
→ The zeptosecond.
This type of clock uses falling water to measure time.
→ A water clock (clepsydra).
This extremely accurate device keeps world time standards.
→ Atomic clock.
The SI unit of time is this.
→ The second.
This modern device adjusts its time automatically using radio signals.
→ Radio-controlled clock.
A day on this planet is longer than its entire year.
→ Venus.
The first wristwatch was invented for this purpose in the 19th century.
→ To help pilots during flying.
This theory introduced the concept that time is relative.
→ The Theory of Relativity.
This term describes 1/100th of a second, commonly used in sports timing.
→ A centisecond.
This island nation is 30 minutes off from most standard time zones.
→ India (UTC +5:30).
This event happens twice a year when day and night are almost equal in length.
→ Equinox.
This system divided the day into 24 hours, still used today.
→ The ancient Egyptians.
This phenomenon makes leap years necessary.
→ Earth’s 365.25-day orbit around the Sun.
This is the only unit of time that is irregular and based on human culture rather than astronomy.
→ The week.
The official time in this country is adjusted by only 45 minutes.
→ Nepal (UTC +5:45).