Re: Can nuclear materials release enough energy to move a thing?

Clare:

The short answers to your questions are, in order, "yes", "any size" 
and "yes".  However, radioactive transformation occurs on an atomic scale 
and the particles and energies involved with the transformations are also 
of atomic or sub-atomic scale.  Your questions suggest that you may may be 
transferring "micro" concepts to a "macro" world.

On an atomic scale, "a thing" might mean a particle such as a beta or 
alpha particle, which can leave the nucleus at a velocity which could be a 
significant fraction of the speed of light.

I think, however, that you might have meant something tangible on the 
macro scale such as, say, a car key.  Could radiation release enough 
energy to move the car key, or perhaps even a car?  If that is your 
question, the answer is still "yes", but it would take a lot more than a 
single radioactive transformation.  For many years, decades actually, 
radioactive decay has been supplying the energy on spacecraft such as 
Voyager to run the radio transmitter and other basic control functions.  
If this energy (milliwatt level) were accumulated over a very long period 
of time, moving a car key, or even the car itself, would be possible.  
Even breaking metal would be possible.

But, in the everyday world, away from spacecraft and scientific 
laboratories, radioactive materials cannot move objects we are familiar 
with.  The car key, or even a feather, will not recoil when hit by a 
particle from radioactive transformation.  Electrons can be knocked off 
and molecular bonds broken on an atomic level, but the energy transfers, 
while very real, are well below the detection ability of our senses.  So, 
the answer to your question could be either "yes" or "no" depending on 
whether you want to consider interactions on the scale of atoms and 
molecules.  If you could clarify the reasons for asking the question, 
perhaps I could be more specific with the answer.