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What's red and bad for your teeth? (sh.itjust.works)
submitted 4 days ago by to c/dadjokes@lemmy.world
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A brick.

If this one already made an appearance on here, I'm sorry. Just got reminded of it while thinking about idioms for hefty books, in english I couldn't find any. In my first language we would say "it's a brick"

Alt version of this joke:

What's red and good for a cop's teeth?Correct! A brick!

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[–] 3 points 2 days ago (1 child)

The formula is wavelength shift over the normal wavelength, multiplied by c. Red is let's say around 600nm and blue is 450. That makes it 150/600. So about a quarter of the speed of light. My initial thought is 2kg mass traveling at a quarter speed of light would probably have a fuck ton of energy that its collision with the atmosphere would not result in friction but a big kaboom.

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  • [–] 2 points 2 days ago

    The formula for kinetic energy is

    KE = 1/2 * m * v^2^

    where m is mass in kilograms and v is velocity in meters per second. Since we already have all of the values, it should just be a quick calculation.

    KE = 1/2 * m * v^2^ = 1/2 * 2 * (299,792,458/4)^2^ = 5.6*10^15^ Joules

    According to Wolfram Alpha, 5.6PJ is about 60% the impact energy that formed Meteor Crater in Arizona .

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