Q 01/05

Which nursery rhyme did Thomas Edison recite in 1877 to test his newly built phonograph?

A) Twinkle, Twinkle, Little Star

B) Mary Had a Little Lamb

C) Baa, Baa, Black Sheep

D) Hickory Dickory Dock

Answer · why

B) Mary Had a Little Lamb

Mary Had a Little Lamb was scratched into a sheet of tinfoil wrapped round a cylinder, then played back. That first recording was never preserved.

Q 02/05

The sharp crack of a bullwhip is produced when its tip travels fast enough to create what?

A) A sonic boom

B) A static spark

C) A small whirlwind

D) A burst of friction

Answer · why

A) A sonic boom

A sonic boom in miniature: a loop racing down the whip speeds up until the tip passes the speed of sound, more than 30 times faster than the handle mo...

Q 03/05

A space explosion would be silent to a nearby astronaut because sound cannot travel through what?

A) Zero gravity

B) A magnetic field

C) A vacuum

D) Cosmic rays

Answer · why

C) A vacuum

A vacuum has no particles to pass the vibrations along. Robert Boyle is credited with discovering the part air plays in carrying sound.

Q 04/05

Which volcano's 1883 eruption made the loudest sound in recorded history, heard 4,800 kilometres away?

A) Vesuvius

B) Tambora

C) Mount Pelée

D) Krakatoa

Answer · why

D) Krakatoa

Krakatoa's blast was heard on Rodrigues, an island near Mauritius, where people took it for cannon fire from a ship.

Q 05/05

The pop heard when people crack their knuckles comes from which of these inside the finger?

A) Bones rubbing together

B) Tendons snapping back

C) Cartilage wearing away

D) Bubbles in joint fluid

Answer · why

D) Bubbles in joint fluid

Bubbles in joint fluid form as the knuckle is pulled apart and dissolved gas comes out of solution. It takes about 20 minutes before the same knuckle ...