# Did Tsar bomba explosion seen in Finland ?

## Main Question or Discussion Point

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 :)

Related Other Physics Topics News on Phys.org
mgb_phys
Homework Helper
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.

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.

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.
Thanks a lot for help :)