[mike2niner4 (OP)]

Michael Perry asked the Naked Scientists:
   
Naked scientists,

I'm wondering, if a bomb or a similar explosion went off underwater, would
the  water amplify or dampen the blast?

What do you think?

[Vern]

I didn't find any good references on this, but my guess is that the concussion would amplify in the inelastic water so that the blast would be felt stronger to objects in the water. But the water would be somewhat of a shield for things outside the water.

 

[DoctorBeaver]

I remember reading somewhere that if you want to blow up a concrete dam it's best to place the bomb underwater as it has more effect.

[yor_on]

Wouldn't the effect be twofold?
At its first microsecond when the blast goes of the force should get more concentrated as the waters higher density will 'resist' it like putting a firecracker into a can giving the force a chance to resonance and dtrengthen its overall effect?

Then you have the fact that sound in water travel faster than on land, depending on salinity, temperature and depth around 1400m/s "We can hardly push things through air (at sea level) at those speeds. The fastest bullets reportedly have an initial velocity about 1500m/s." The reason why is also its density When you pack molecules close (as in water as compared to air) they will react and pass the 'sound waves' on so much faster, between four to five times the speed of sound in air. And after all the 'blasting force' is just that, molecules 'flying away' in 'shock waves' through whatever medium they travel.

So how about outer space then, there you have nothing, well almost nothing:) Will a blast there give any effect at all, I'll leave that one to you

[Vern]

I suspect that in space you would be subject only to the ejecta from the explosive device.

[yor_on]

Yep,  that's what I think too Whatever molecules there might be will probably belong to the device exploding, and they will disperse quite near the explosion without finding anything to propagate it further with.

[tony6789]

wouldnt

I remember reading somewhere that if you want to blow up a concrete dam it's best to place the bomb underwater as it has more effect.

wouldnt that just b-because u would want an explosion to happen at the bass of the dam so the rest will crumble??

[tony6789]

since water cant be easily compressed the force of an explosion underwater transfers far more of the energy of a greater distance

[yor_on]

Tony that was mighty mystical
It's a truth with a disclaimer I think.

If you mean that waters density helps it transfer the shockwaves better than air then that is a truth, But it won't work better if embedded in a diamond, then the blast will be highly contained and not able to travel long at all. What works for fluids is not the same as for solids. Do you agree?

[tony6789]

ok not completely understanding wat ur saying...are u asking if a bomb was encased in a large diamond?? if so (assuming the bomb is powerful enough to explode the diamond) then yea it will likely weaken the bombs power. so yea i agree to an extent

[thedoc]

Listen to the answer to this question on our podcast.