Re: [Phys-L] comparing damage versus comparing energy

[John Denker <jsd@av8n.com>]

On 09/07/2017 09:54 AM, bernard cleyet wrote:

> The devastation pictures of Hiro-Naga (well,  at the edges) and
> Barbuda are similar.  A great diff. is the time, i.e. seconds vs.
> hours.
>
> http://people.com/human-interest/hurricane-irma-wreaks-havoc-islands/
>
> Anyone done the calcs?

It would be easy to do the energy calculations, but it's even easier
to figure out that the calculation is not worth doing.  Destruction
is not proportional to energy.  It's way more complicated than that.

Even within the class of explosives -- which is a very narrow
class, and does not include hurricanes -- you can have two
explosives with the same energy but wildly different brisance.
 -- High-brisance explosives are often preferred for military applications.
 -- Low-brisance explosives are preferred for e.g. coal mining, where
  you want heaving power, not shattering power.  You do not want to
  reduce the coal to dust.

==============

In any two scenes of destruction, you can find similarities,
especially at the edges -- *IF* you define the "edge" to be
the place where X type of destruction is observed.  However,
this is just an artifact of selecting the data.  If you look
more closely, you discover major dissimilarities between
hurricanes and explosions.

For starters, keep in mind that year in and year out, there
is more death and destruction from flooding than from direct
wind effects.