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Did Tsar bomba explosion seen in Finland ?

  1. Mar 31, 2010 #1
    Hello :)

    When I read about Tsar Bomba, I find that all sites say "The fireball touched the ground, reached nearly as high as the altitude of the release plane and was seen and felt almost 1,000 kilometres (620 mi) from ground zero."

    Diameter of the fireball is 8 km.

    Now , there are some premises :

    1 Distance between the explosion & point that fireball seen is 1,000 km.
    2 Circumference of the earth is about 40000 km.
    3 Angle between the two lines which passes through center of the earth & ( ground zero & 1000 km point ) = (1000/40000)*360 = 9 degrees.
    4 Sight line of 1000 km point is the tangent of the earth.
    5 To see the explosion from 1000 km point , fire must be at least 79.5 km high.

    this conclusion came from:

    hight of the fire to be seen 1000 km far = ( Radius of the earth / Cos (9 degrees ) ) - Radius of the earth.


    so , how could the explosion seen from this distance when the hight of the fire is only 8 km ?

    thanks for help :)
     
  2. jcsd
  3. Mar 31, 2010 #2

    mgb_phys

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    The question is essentialy a distance-to-horizon problem - but the other way around
    Imagine an observer at the top of cloud looking to a point on the ground in finland

    Distance to the horizon is roughly sqrt( 13*h ), with h in metres
    So if h is 8km, 8000m, the horizon is = 320 km, so no you can't see the cloud directly.

    You might have seen a flash due to the explosion illuminating high level clouds and reflecting the light, or some atmopsheric effect of exciting ions in some upper level.
     
  4. Mar 31, 2010 #3
    Tsar Bomba was a 57 megaton hydrogen-bomb (which was decimated from its originally intended size of 100 megaton by removing material) and it is the largest device ever detonated on this earth (at least in atmosphere). In 1961. Everybody got the message. Yes, it was reported as seen in Finland. And the blast wave was recorded three times (it circulated the earth). OK, so we know that you can blow it all up. So what? What now? Let's talk.
     
  5. Apr 1, 2010 #4
    Thanks a lot for help :)

    could you guide me to articles about this effect of illumination & the atmospheric ions ?

    Thanks a lot :)
     
  6. Apr 2, 2010 #5
    The diameter of the fireball might have been only 8 km, but I'm sure it didn't just chill there until it disappeared. I wouldn't be surprised if it rose to pretty close to the height that you calculated, where it could have been seen from Finland...
     
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