mock, mach

Mock or mock means to ridicule or make fun of--
His classmates would often mock his studious attitude.
Mock also describes something imitation--
We are having mock turtle soup for dinner.
She wants a mock turtleneck sweater for her birthday.

Mach or mach ( rhymes with mock ) means the speed of sound--
The first pilot to break the sound barrier flew faster than mach 1, or the speed of sound.
Mach 1 is about 760 miles per hour.

Now that you know that, you can say--
"It later seemed foolish to mock the first attempts to fly faster than mach 1."