Trivia

Hard

Atomic Time Is Kept Using Atoms Of What Type?

Uranium
Einsteinium
Radium
Caesium

Answer: Caesium

The exact definition of a second has undergone quite a few revisions over the centuries. The second was originally defined as the second division of the hour by 60 (the first division was the minute).

Loose time keeping well into the 19th century however meant that a second was fairly fluid if it was even measured at all. By 1892 scientists had finally hammered out a more precise definition: the fraction 1/31,556,925.9747 of the tropical year for 1900 January 0 at 12 hours ephemeris time.

That definition was refined for next seventy years or so until the  International Committee for Weights and Measures abandoned the idea of linking the scientific second to explicitly to length of the day. Instead the second would be defined via atomic clock, specifically: 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-133 atom.

Although atomic clocks have been improved many fold since the 1960s, isotopes of the caesium atom have been keeping time for us ever since.

Trivia

Hard

Nyctalopia, Or Night Blindess, Is Caused By A Deficiency Of Which Vitamin?

Trivia

Hard

Which Creature Uses The Poisonous Tentacles Of The Portuguese Man O’ War Jellyfish As Weapons?

Trivia

Easy

The Acid Mixture “Aqua Regia” Derives Its Name From The Ability To Dissolve?

Trivia

Hard

What Tiny Creatures Live In Old Books And Protect Them From Harm?

Trivia

Hard

Who Invented the Time Ball, Predecessor of the New Year’s Eve Ball?

Trivia

Hard

Which Serial Killer Was Caught Via The Metadata In A Microsoft Word Document?

Trivia

Very Hard

The Humble Second Derives Its Name From What Source?

Trivia

Hard

The Largest Stadium In The World Is Located In?

Trivia

Hard

The Eiffel Tower Was Originally Painted?

Trivia

Hard

Which Of These Pigments Is Also A Life Saving Medicine?