The change in pitch of a sound heard by a listener when the source and observer are in relative motion to each other. As the observer and sound source come together, the perceived pitch is higher than ...

We have all noticed how the horn of a speeding car changes as it approaches: each wave-peak is emitted from a closer point, so the wave is “squeezed” and the pitch increases. As the car recedes, the ...

MADISON — What if the speed of light is a constant only most of the time? What if gravity sometimes pushed instead of pulled? Scientists are increasingly asking what would seem like far-out questions ...

A team including researchers from The University of Manchester’s National Graphene Institute (NGI) has revealed that sonic boom and Doppler-shifted sound waves can be created in a graphene transistor, ...