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Light bulb inside a box

  1. Feb 4, 2016 #1
    I put a light bulb inside a box and make it glow, is there a way to know where the light bulb is if the box is closed and not transparent
     
  2. jcsd
  3. Feb 4, 2016 #2

    berkeman

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    Sure. What are your thoughts? :smile:
     
  4. Feb 4, 2016 #3
    We human have not advance far in science(I have no idea)
     
  5. Feb 4, 2016 #4

    berkeman

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    What is the context of the question? What are the constraints?

    Given different constraints, I can think of at least 3 ways of locating the light bulb in the box...
     
  6. Feb 4, 2016 #5
    Some type of x ray vision? Some kind of imaging technique
     
  7. Feb 4, 2016 #6

    berkeman

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    Yes, that would be one way. You need to take 3 x-rays to get the full (x,y,z) position.
     
  8. Feb 4, 2016 #7
    Or 2, 2 dimensional x-ray pictures...
     
  9. Feb 4, 2016 #8

    sophiecentaur

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    If it's a filament bulb (producing significant heat), you could take thermal images of the six faces. The temperature distribution over the faces could give a good indication of the bulb's position.
     
  10. Feb 4, 2016 #9

    anorlunda

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    1. Finding the box's balance point should reveal the bulb's position; centered, or on one side, or in a corner.
    2. Shaking the box would tell us if the bulb is free to move in the box. If yes, stop shaking. The bulb will be at the lowest point.
    3. If wires stick out of the box, pull them. The bulb should be drawn to the point where the wires penetrate.
    4. Crush the box down to the shape of the bulb.
    5. You put the bulb in. I'll force you to tell me where in the box you put it. Alternatively, I'll watch the video of you putting it in.
    6. I'll guess the position and challenge you to prove me wrong.
    Thanks for the OP. This is fun. When you make a challenge like this, locking down the rules is the hardest part. Changing the rules is the most fun part for the challenger.
     
  11. Feb 4, 2016 #10
    7. spinning the box to determine center of mass...
     
  12. Feb 4, 2016 #11

    anorlunda

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    8. Cause the bulb to shatter. The pieces will be found at the bottom.
    9. If an incandescent bulb, use a DC current and a compass needle to detect magnetic fields.
    10. If fluorescent or LED, look for RF interference.
    11. If incandescent, use low frequency AC. Listen for the mechanical vibrations at 2x the AC frequency as the filament expands and contracts with instantaneous power.
     
  13. Feb 4, 2016 #12
    12. sonar?
    That would be adaptable I think... like how a bat could see it, perhaps.
     
  14. Feb 4, 2016 #13

    anorlunda

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    Sure, use sonar, call it ultrasound. Good one.

    Who is up for 13?
     
  15. Feb 4, 2016 #14
    I did at first and changed it... wasn't sure if it works through air...
     
  16. Feb 4, 2016 #15

    anorlunda

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    The OP did not specify air, and we are having fun finding all the loopholes in his problem statement.
     
  17. Feb 4, 2016 #16
    ...now I'm having fun wondering if bats can "see" through walls... too! I just googled it and found something about cellphone seeing through walls...
     
  18. Feb 4, 2016 #17

    anorlunda

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    13. Radar. No limits on the box or bulb size in the OP, so radar could locate a big bulb.

    14 anyone?
     
  19. Feb 4, 2016 #18

    CWatters

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    14. Pipe or metal detector.
    15. If it's one of these Philips bulbs.. Hack into the chip in the bulb and ask it where it is :-)
    http://www.bbc.co.uk/news/technology-32848763
     
  20. Feb 4, 2016 #19

    jbriggs444

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    Since the rules do not specify that we are outside the box, simply look at the bulb and see where it is.
     
  21. Feb 4, 2016 #20
    What if I want to see the light from the light bulb?
     
  22. Feb 4, 2016 #21
    16. ask Schrodinger's cat where it is
     
  23. Feb 5, 2016 #22

    256bits

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    17. If the box is wood or cardboard, bring in termites - they should eat the box letting you see where the bulb is.
    18. Let the box corrode, erode chemically, mechanically - you should then see where the bulb is
    19. Poke fine rods through the box - obstruction, you are hitting some part of the bulb.
    20. Place moths with accurate and precise GPS - record their movement and one can determine where the bulb is.

    21 is the challenge

    Edit - had to edit the list #
     
  24. Feb 6, 2016 #23
    Magnetic resonance 3D imaging. That tells not only where cancerous masses are but their shape/ size and where tiny gold implanted reference spheres (markers for daily localized radiation treatments extending over weeks, to not do too much damage to normal tissue) are.

    Modern MRI machines used with accurately shaped beams from linear accelerators. The cross section shape of beam changes with beam approach angle to be same as the cross section area of the target "seen" from the current beam angle.
     
    Last edited: Feb 6, 2016
  25. Feb 6, 2016 #24
    Make separately large thermal gradients across the box (one for each direction thru box) and with no power applied, measure the resistance between the wires. This assumes lamp is a tungsten filament type. The resistance hot, is almost twice that when cold. (Why those lamps often burn out at first turn on - large initial current surge.)
     
  26. Feb 6, 2016 #25
    By using thermal camera shoot the box surface from the top, front and right side could be known the light bulb position. Good luck.
     
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