Fascinating Time Facts
Fascinating Time Facts

28 Time Facts You Wish You Didn't Know

Karin Lehnardt
By Karin Lehnardt, Senior Writer
Published August 30, 2025
  • Language profoundly affects the way a person perceives time. For example, English speakers describe time as being either in front or behind them and as moving from left to right, much like their sentence structure. In Hebrew, the past is in front and the future behind, and Hebrew sentence structure goes from right to left. Conversely, Mandarin speakers perceive time as a vertical line, where down represents the future. In Pormpuraaw (an Australian Aboriginal community), time is structured from east to west.[2]
  • Without time, consciousness might not exist. A person's thoughts, memories, and sense of self rely on time unfolding. Even if time is illusion, the human brain needs a sense of time to interpret reality and to create a sense of self.[3]
  • Known as the "oddball effect," time seems shorter for people who live a life of repetition and routine, while mindfulness and seeking out new experiences help time feel longer and richer.[14]
  • While 17th-century Issac Newton believed that time was like an arrow fired from bow, traveling in a straight line for everyone, Einstein believed that time was more like a river, changing its flow depending on gravity and speed.[7]
    • Jilaatomicclockk facts
    The clock is so precise that it would lose just one second in 40 billion years (Ye Group and Baxley / JILA)
  • Scientists at the Joint Institute for Laboratory Astrophysics have created the world's most accurate and precise atomic clock that bridges quantum theory and gravitation.[16]
  • There are two main ways to measure time: dynamic and atomic. Dynamic is based on motion, primarily Earth's rotation around the Sun or the moon's movements. Atomic time is based on atomic vibrations and is extremely accurate and stable.[7]
  • Einstein defined time as the fourth dimension. The other three dimensions are length, height, and width. His addition of time created the concept of space-time.[7]
  • Planck time is the shortest unit of time known in physics. Below this theoretical time measurement, the known laws of physics breakdown. It would take about 550 thousand trillion trillion trillion Planck times to blink once. A zeptosecond is the shortest amount of time actually ever measured in a lab.[17]
  • A gnomon is the part of a sundial that casts a shadow to show the time of day. The earliest sundials date back to 3500 BC in Egypt and Mesopotamia and divided the day into 12 parts. The word "gnomon" comes from the Greek "one who knows," or "indicator."[3]
  • The word "time" is from the PIE *di-mon-", which is a form of the root "da-", "to divide." So, time comes from the idea of "dividing" up existence. The word "tide" is also related and can be seen in words such as "eventide," and "Yuletide."[15]
  • The Ishango Bone may have been one of the earliest tools for measuring time. Dating back to 20,000 BC, it shows tally marks that may have tracked the phases of the moon.[4]
  • In 1500 BC, water clocks (clepsydra) were used in Egypt, Babylon, India, and China to mark time. This method was particularly useful at night or on a cloudy day, when sun dials could not be used. Water would drip at a steady rate to mark the time.[9]
  • Scientists hypothesize that the largest measurement of time is likely 10 to the 120th years, which is the expected lifespan of the universe before everything decays. Called "heat death," this is when the universe reaches maximum entropy, and it is theoretically the end of the universe and of time.[6]
    • Crazy Time Facts and the death of time
    Does the end of time exist?
  • Time passes slower for a person's feet than it does a person's head. This is known as "gravitational time dilation": the closer you are to the center of the earth, the slower time goes.[4]
  • A second is defined as "the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium atom." Before atomic clocks, the second was defined as a fraction: 1/86,000 of a solar day.[4]
  • A businessman named John Belville started to sell time in 1836. He would set his pocket watch every morning at the Greenwich Observatory and then sell his precise time to clients around the city. After his death, his widow continued the business until 1940.[1]
  • A day is not exactly 24 hours long. It is actually 23 hours, 56 minutes, and 4.2 seconds.[4]
  • American clockmaker Levi Hutchins invented the first modern and affordable alarm clock in 1787. It could only ring once during the day, at his preferred wake up time of 4:00am.[11]
  • The world's oldest surviving clock is from 1386 and is located in Salisbury Cathedral, UK. It has ticked more than 500 million times.[8]
  • Everything we see is from the past because it takes time for light to get to us. The light from our nearest star, Prima Centauri, is about 4 years old.[12]
    • Time and the Brain Facts
    The brain's reaction time is about 80 milliseconds, which means we are always slightly living in the past
  • It takes the brain about 80 milliseconds to process an event after it happens, which means the present is an illusion.[13]
  • Time is measured in astronomical, atomic, and civil time. Astronomical time is based on the measurement of celestial bodies (sun, moon, planets). Atomic time is based on the vibrations of atoms (Cesium-133), and civil time is the official time we use daily.[5]
  • The closer a person is to a massive body, the slower time passes for that person.[4]
  • The oldest known object formed on the earth is the Jack Hills Zircon crystal, at 4.4 billion years old. It is just 160 million years younger than the earth, which is 4.543 billion years old.[10]
  • The word "clock" comes from the Latin clocca, which means "bell."[11]
  • The ancient Greek philosopher Plato invented a water clock that also whistled to wake him up in the morning.[11]
  • The snooze button was invented in 1956. Because of the size and shape of alarm clocks at the time, the snooze option could only last 9 minutes, not 10.[11]
  • The term “o’clock” is a contraction of “of the clock" and is from 15th-century references to medieval mechanical clocks. At the time, sundials were also used to track time, so to make it clear they were referencing a clock, people would use phrasing like, “It is six of the clock."[12]
READ MORE
References

Suggested for you

Prev
Next

Trending Now

Load More
Suggested For You
Earth Fact
62 Amazing Earth Facts
The story of Earth is dynamic and beautiful. From volcanoes to the deep blue oceans, discover the majesty of your world with these interesting Earth facts.
Mars Facts
53 Interstellar Facts about Mars
Skywatchers have long been fascinated by the Red Planet. Adventure through our interesting Mars facts to discover more about what makes Mars so special.
Milky Way Fact
48 Amazing Milky Way Facts
A luminous river of stars, the Milky Way both inspires and awes. Peer into our interesting Milky Way facts to learn about our amazing and beautiful galaxy.
Sun Facts
29 Brilliant Facts about the Sun
Variously worshipped, loved, and feared, the Sun has always held a central place in human history. Explore its brilliance with our interesting Sun facts.
>