Ever create your own Doppler effect?- Mtbr.com
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  1. #1
    mtbr member
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    Ever create your own Doppler effect?

    I was riding last week past a backing-up construction vehicle making the "beep-beep-beep.."

    I was going fast enough to create a Doppler effect! It dropped in pitch significantly as I passed.

    Made me feel good (...and speedy)!

    Anyone else?

  2. #2
    Picture Unrelated
    Reputation: zebrahum's Avatar
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    I thought you meant that when you ride past things you change the pitch of the sounds you are making; like making sounds as if you were a motorcycle passing things. If that were the case then yes, yes I do.
    Don't you hate it when a sentence doesn't end the way you think it octopus?

  3. #3
    I'm SUCH a square....
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    All the time; so much so that it's a little annoying anymore.
    A bike is the only drug with no bad side effects....

  4. #4
    Unhinged Aussie on a 29er
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    Speed of sound at sea level in air: 343.2 m/s
    Speed of cyclist @ 30 km/h (20 mph): ~ 8.3 m/s
    Middle C on a piano keyboard: 261.626 hz

    Pitch approaching sound source at 20 mph: 268.11 hz.
    Pitch departing source at 20 mph: 255.44 hz.

    Source: The Doppler Effect for Sound

    So yeah, 20 mph should be enough to have a noticeable variation in the doppler effect. If you have perfect pitch hearing, it should be noticeable at lower speeds, but that would vary from person to person.

    FWIW, if you Powershell installed on your computer (standard in Win7 IIRC), you can emulate the difference using your computer speakers using the following commands:
    [console]::beep(268.11,500); [console]::Beep(255.44,500)

  5. #5
    jrm
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    Yes..

    with my bell riding past a bus depot/garage.

  6. #6
    Bedwards Of The West
    Reputation: CommuterBoy's Avatar
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    Quote Originally Posted by zebrahum View Post
    I thought you meant that when you ride past things you change the pitch of the sounds you are making; like making sounds as if you were a motorcycle passing things. If that were the case then yes, yes I do.
    Exactly
    You have no excuse for driving to work
    (unless you don't have studded tires)
    (no excuse for that either)

  7. #7
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    Everyone knows what happens when you hit 88mph. I haven't hit it yet...anyone here?
    GoatRidesBikes.com
    Goat Rides Bikes @ YouTube
    "I may be old and fat, but at least I'm slow." - Me

  8. #8
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    Quote Originally Posted by bikeCOLORADO View Post
    Everyone knows what happens when you hit 88mph. I haven't hit it yet...anyone here?
    If only I would have installed a flux capacitor! 1.21 gigawatts!?

  9. #9
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    If you can pedal a bike to 88mph on flat ground....you might be on your way to generating 1.21 gigawatts.
    GoatRidesBikes.com
    Goat Rides Bikes @ YouTube
    "I may be old and fat, but at least I'm slow." - Me

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