The Mysterious Leap Second

TL;DR

Leap days are added every four years to correct for the extra six hours it takes for the Earth to orbit the Sun. In addition to leap years, leap seconds are also added to account for the Earth's slowing rotation.

Transcript

Hello and happy leap day! It's February 29th or it will be or it was a day when we celebrate ,we don't actually celebrate anything leap day is more of an acknowledgement that it takes more than 365 days 365 days in about six hours for us to orbit the Sun so every four years we need to correct for those six hours by adding a full day because 4 times... Read More

Key Insights

• 🥳 Leap days are added every four years to align our calendar with the Earth's orbit.
• 🐢 Leap seconds are added to compensate for the Earth's slowing rotation caused by the moon's gravitational effects.
• ⏲️ Atomic clocks provide more consistent and accurate timekeeping compared to mean solar time.
• 🇪🇺 The International Telecommunication Union Bureau of the UN has the authority to decide whether to continue using leap seconds.
• ❓ The decision on whether to eliminate or retain leap seconds has been postponed until 2015.
• ⌛ The addition of a leap second can cause disruptions to computer systems and time-dependent technologies.
• 🥺 Eliminating leap seconds may lead to larger discrepancies between atomic time and the Earth's rotation in the future.

Questions & Answers

Q: Why do we have leap years?

Leap years are added every four years to account for the extra six hours it takes for the Earth to orbit the Sun. By adding a leap day, we can keep our calendar aligned with the Earth's orbit.

Q: What are leap seconds?

Leap seconds are added to account for the Earth's slowing rotation. The gravitational effects of the moon cause the Earth's rotation to gradually slow down, resulting in days being one to two milliseconds longer in 2012 compared to 1912. Leap seconds are added to atomic clocks to maintain accurate timekeeping.

Q: How are atomic clocks used for timekeeping?

Atomic clocks measure the oscillations of an atom to determine time with high precision. Since 1967, a second has been defined as a specific number of these oscillations. Atomic clocks are more consistent than mean solar time based on the Earth's rotation and remain accurate within one second for millions of years.

Q: Why are some people against leap seconds?

Some people argue that adding leap seconds is unnecessary and causes disruptions to computer systems and other time-dependent technologies. The manual adjustment of these systems to accommodate leap seconds can be challenging. However, proponents of leap seconds argue that eliminating them would create more significant issues in the long run.

Summary & Key Takeaways

• Leap days are added every four years to account for the extra six hours it takes for the Earth to orbit the Sun.

• Leap seconds are added to account for the Earth's slowing rotation, which is caused by the gravitational effects of the moon and result in days being one to two milliseconds longer in 2012 compared to 1912.

• Atomic clocks, which measure the oscillations of an atom, are used for precise timekeeping and are more consistent than mean solar time based on the Earth's rotation.