Amazon is experimenting with a different Echo name, and it's one that's so perfect I wish they'd just do it today.

Sound waves can reflect off surfaces ... If we know the speed of sound and the time it takes for the echo to be detected, we can use the equation: Speed = \(\frac{\text{distance}}{\ ...

Electromagnetic radiation in the form of light or sound waves hit a mirror or wall, respectively, and change course. This allows our eyes to see a reflection or echo of the original input.