When a train approaches or an ambulance with its siren blaring nears us, we hear the sound with an increased frequency, gradually decreasing slightly. As it passes, the frequency changes abruptly to a lower one, then decreases further. This commonly encountered Doppler effect can be a valuable clue to the nature of a phenomenon seemingly completely unrelated to sound propagation: heat transport. When a train approaches or an ambulance with its siren blaring nears us, we hear the sound with an increased frequency, gradually decreasing slightly. As it passes, the frequency changes abruptly to a lower one, then decreases further. This commonly encountered Doppler effect can be a valuable clue to the nature of a phenomenon seemingly completely unrelated to sound propagation: heat transport. General Physics Phys.org – latest science and technology news stories
From burns to the wave nature of heat—via the telegraph equation
