|MadSci Network: Earth Sciences|
As far as I'm aware, nobody has tried to build such a device, there's
probably a few reasons for that:
First, the machine would be huge and would require a lot of energy.
Basically you'd need something that could put out something like the same amount of energy that the tornado does. According to this site, a 200km/hr tornado contains about 1 Billion watts of kinetic energy. That's a tremendous amount- about the same as the electical output of two nuclear power plants. Plus, the machine would have to convert the energy into a form (kinetic or heat) that could be used to "counteract" the tornado (and energy is always lost when it is converted).
Even if one could overcome that problem, there would still be the problem of getting it to the tornado. Tornado researchers (e.g. the VORTEX project) are not very good a predicting where and when a tornado will occur. I heard a story once about some early tornado researchers who had an instrument package they wanted to get sucked up by a tornado, where it would measure wind speeds, temperatures, etc. The major problem with that instrument was getting it into a tornado! They would go to tornado prone areas when they were likely to form, then try to drive in front of them and dump the instrument package in its path. As far as I'm aware they never were successful in getting in inside a tornado (now scientists use things like radar to study tornadoes from a little further away). Any "anti-tornado device" would have the same problem.
Or, if you think about it in terms of the example you gave for how a tornado was stopped, how would you make a device that makes rain/hail storms at times and places you specify? As a wannabe mad scientist myself, I'd love to have a weather machine, but as yet they are not a practical possibility!
I hope that helps,
Rob Campbell, MAD Scientist
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