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I Speed of Light Thought Experiment

  1. Jul 29, 2017 #1
    A thought experiment about the speed of light. Say I build a 600,000 km long tube around the circumference of the earth at the Equator. The tube's inner diameter is constant at 54.4505 mm. A snooker ball is perfectly manufactured to its lowest tolerance by a special new machine. Each one is 54.4501 mm in diameter. I fill said tube with snooker balls (btw the tube wraps around Earth's circumference at the Equator approximately 25 times, so there are approximately 11,440,000,000 of them. I have assumed light travels 300,000 km every second. I am also in possession of a super powerful pushing arm with Giga-tonnes of pushing power, which is needed even though the tube is frictionless due to the sheer number of snooker balls it needs to displace. 25 diameters up from where I start pushing, a ball pops out in 1 second. The 'signal' necessary for it to do so has just travelled 600,000 km in one second. Yet light can only travel half that distance in the same time. Voila!!! Faster than light information transmission. Okay, what am I missing if anything?
  2. jcsd
  3. Jul 29, 2017 #2


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    Staff: Mentor

    Yes you are missing something. What is the speed of sound in snooker balls?

    Welcome to the PF, BTW. :smile:
    Last edited: Jul 30, 2017
  4. Jul 29, 2017 #3


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    Science Advisor

  5. Jul 29, 2017 #4


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    Gold Member

    @Jopus Foghlu don't feel bad. We've had probably several hundred people come here and ask that so you're not alone in your misconception.
  6. Jul 29, 2017 #5


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    Staff: Mentor

    Props for creativity though!
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