Trivia

Hard

Atomic Time Is Kept Using Atoms Of What Type?

Uranium
Caesium
Einsteinium
Radium

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

Which Common Computer Cable Was Named After A Debunked Scientific Theory?

Trivia

Very Hard

Alexander Graham Bell Believed Which Of These To Be His Greatest Invention?

Trivia

Hard

Leonard Nimoy Based The Vulcan Salute On A Symbol From Which Cultural Group?

Trivia

Hard

Highlighting Missing Children On Milk Cartons Gained Traction After The Abduction Of Two?

Trivia

Hard

A Pen Invented By Thomas Edison Is Still In Use Today For What Purpose?

Trivia

Hard

The Standard Galactic Alphabet From Commander Keen Also Appears In Which Of These Games?

Trivia

Hard

Vocal Pauses Like “Uh” and “Um” Are Known As?

Trivia

Hard

What Are The Plastic Lumps Found On The Ends Of Computer Cables Called?

Trivia

Very Hard

Which Country Is The Largest Exporter Of Cigars In The World?

Trivia

Very Hard

Due To Early Industry Limitations, Silent Films Were Recorded In?