Mathematics
40 has These prime factors.
What are 2, 2, 2, and 5
In 1919, Sir Arthur Eddington made observations of the sky before and during a Solar Eclipse in order to provide supporting observations for this physicist's Theory of Relativity
Who was Albert Einstein?
This Broadcast Network unveiled the Peacock logo that is uses to this day.
____ 40 Hands is a drinking "game" (challenge?) whose name is a reference to a titular movie character with these for hands.
What are Scissors?
This number is equal to 402
What is 1600?
Marie Tharp lead a team of geologists to produce a topological map of the Atlantic Ocean Floor. Her findings were eventually used to prove this then-fringe geological theory.
What is Plate Techtonics?
This nuclear power plant melts down in Ukraine, resulting in the worst nuclear power related accident in all of human history.
What is the Chernobyl Nuclear Power Plant?
This country, home of Transylvania, has the international telephone code 40.
What is Romania?
There are 40 of this type of number between 1 and 175.
After being honored in the New York Pride rally in June 1985, she helped to organize the first AIDS Walk in Los Angeles in July. She also participated in AIDS dance-a-thons in New York.
Who is Marsha P. Johnson?
This American landmark celebrated its centennial. Itself being a centennial celebration, delayed by a war.
What is the Statue of Liberty?
The tenth and final song is U2's album War is titled 40, and also this question.
What is "How Long"?
40 is in this Set of numbers
What are natural Numbers?
This computer scientist led the development of the on board flight software for the Apollo program and founded the software company Higher Order Software in 1976.
Who is Margaret Hamilton?
This animated movie studio was founded by John Lasseter and Steve Jobs
What is Pixar?
This is 40, starring Leslie Mann and Paul Rudd, is a "Sort of Sequel" to this movie, starring Katherine Heigl and Seth Rogan.
What is Knocked Up (2007)?
A complete Graph with 40 vertices will have this many edges. (This is the same as the number of unique pairs that can be made from 40 elements)
What is 680?
This teacher with roots in Union Organizing is starting what she plans to be the best decade of her life.
Who is Natalie Kelly?
1986 was the most recent time This comet was in the inner parts of the solar system and was thus visible to the naked eye.
What is Halley's Comet?
This ASCII character is number 40.
What is "("? (Open Parenthesis)