Q 01/05

What does the acronym SONAR stand for?

A) Sound navigation and ranging

B) Sound observation and recording

C) Submarine oscillating navigation array

D) Sonic navigation and radar

Answer · why

A) Sound navigation and ranging

Sound navigation and ranging was patterned on radar; Harvard's Frederick Hunt said he coined sonar around 1942 to make the Navy sound operator's job s...

Q 02/05

What turned out to cause the 'false bottom' that early sonar found in the deep ocean?

A) Drifting volcanic ash

B) Sunken wartime wreckage

C) Swarms of small sea animals

D) Pockets of undersea gas

Answer · why

C) Swarms of small sea animals

Swarms of small sea animals, often fish, made the echoes; the layer rose toward the surface each evening and sank at dawn, which first suggested it wa...

Q 03/05

Who wrote around 1490 that a long tube dipped in water lets you hear ships far away?

A) Christopher Columbus

B) Galileo Galilei

C) Leonardo da Vinci

D) Amerigo Vespucci

Answer · why

C) Leonardo da Vinci

Leonardo da Vinci's instructions were to stop your own ship first, then put one end of a long tube in the water and hold the other to your ear.

Q 04/05

Which maritime disaster spurred a wave of patents for detecting obstacles with underwater echoes?

A) The Lusitania sinking

B) The Halifax Explosion

C) The Empress of Ireland sinking

D) The sinking of the Titanic

Answer · why

D) The sinking of the Titanic

The sinking of the Titanic in 1912 drove the idea that a pulse's echo off an iceberg's hidden bulk could warn a ship, and the same pulse aimed down co...

Q 05/05

Which Canadian engineer detected an iceberg by echo ranging off Newfoundland in 1914?

A) Reginald Fessenden

B) Guglielmo Marconi

C) Lee de Forest

D) Alexander Graham Bell

Answer · why

A) Reginald Fessenden

Reginald Fessenden's employer marketed his oscillator for underwater telegraphy and was reluctant to exploit its potential for finding icebergs and su...