Who developed the assembly line

who developed the first atomic reaction

who invented the first telegraph

who invented the light bulb

who was the "father of the hydrogen bomb"

who was an author, diplomat, scientist, and inventor

Explanation:

Assembly line

On December 1, 1913, Henry Ford installs the first moving assembly line for the mass production of an entire automobile. His innovation reduced the time it took to build a car from more than 12 hours to two hours and 30 minutes

first atomic reaction

Chicago Pile-1 (CP-1) was the world's first artificial nuclear reactor. On 2 December 1942, the first human-made self-sustaining nuclear chain reaction was initiated in CP-1, during an experiment led by Enrico Fermi.

Telegraph

Samuel Morse independently developed and patented a recording electric telegraph in 1837.

light bulbs

In 1878, Thomas Edison began serious research into developing a practical incandescent lamp and on October 14, 1878, Edison filed his first patent application for "Improvement In Electric Lights".

Father of hydrogen bomb

Edward Teller (Hungarian: Teller Ede; January 15, 1908 – September 9, 2003) was a Hungarian-American theoretical physicist who is known colloquially as "the father of the hydrogen bomb"

author diplomat scientist and inventor

Benjamin Franklin, also called Ben Franklin, pseudonym Richard Saunders, (born January 17 [January 6, Old Style], 1706, Boston, Massachusetts [U.S.]—died April 17, 1790, Philadelphia, Pennsylvania, U.S.), American printer and publisher, author, inventor and scientist, and diplomat

the answer i chose to believe is 'harmony'