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Cake day: July 2nd, 2023

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  • Austrian here: some cars were already taken away, but mostly just temporarily. Also the car won’t be gone at the first offence, only if you are caught multiple times.

    So losing your car won’t happen “by accident”. To lose your car, you have to drive much too fast (something like this is done deliberately) multiple times (then your are an idiot who shouldn’t drive).

    I dont pity anyone who lost his/her car. They are idiots, which shouldn’t share a road with others.







  • Sooooo, wavelengths (λ) become longer when something moves away (redshift) and become shorter when something moves towards you (blueshift).

    For a red flag (λ0=610nm) to become a green flag (λ1=549nm), it has to move towards you quite fast. But how fast is ‘quite fast’?

    Using the formula

    flag_velocity / speed of light © = difference in wavelengths / starting wavelength

    we get

    flag_velocity = (610-549) / 610 * c = 61 / 610 * c = 1/10 * c

    This means: the flag has to move with about c/10 = 30 000 000 m/s = 108 000 000 km/h = 67 108 100 mph. Yeah, that’s quite fast.

    (Disclaimer:

    1. use info on own risk

    2. values for λ were chosen in a way to make calculations easy. There is no info on what shade of red or green the flag is. The final result will be about the same.

    3. With speeds at around 10% of c, I should use the formula considering the relativistic doppler effect… However, i wont. Thanks.)


  • Sooooo, wavelengths (λ) become longer when something moves away (redshift) and become shorter when something moves towards you (blueshift).

    For a red flag (λ0=610nm) to become a green flag (λ1=549nm), it has to move towards you quite fast. But how fast is ‘quite fast’?

    Using the formula

    flag_velocity / speed of light © = difference in wavelengths / starting wavelength

    we get

    flag_velocity = (610-549) / 610 * c = 61 / 610 * c = 1/10 * c

    This means: the flag has to move with about c/10 = 30 000 000 m/s = 108 000 000 km/h = 67 108 100 mph. Yeah, that’s quite fast.

    (Disclaimer:

    1. use info on own risk

    2. values for λ were chosen in a way to make calculations easy. There is no info on what shade of red or green the flag is. The final result will be about the same.

    3. With speeds at around 10% of c, I should use the formula considering the relativistic doppler effect… However, i wont. Thanks.)