The new version could also be interpreted as saying 'the breeze from ceiling fans can reanimate the dead'...
Agreed. It would make much more sense rearranged like this http://oi51.tinypic.com/15hzdcj.jpg
You know, that makes me think - arrows seem totally obvious to us, but would they be obvious to someone from a completely different culture? <- could be 'go this way'; it could also mean 'avoid as if it's the mouth of a crocodile'.
Well as they said above, to dig that deep the civilization needs a non trivial technology, so I would think any human with an index finger would get it (but the problem remains for those who don't have fingers).
http://en.wikipedia.org/wiki/Radiation_symbol#Radioactive_si...
In fact, the symbol is so completely unintuitive that ISO came up with a new version:
http://upload.wikimedia.org/wikipedia/en/1/10/New_radiation_...
... which to me certainly does connote "these rocks shoot death rays!" as well as the sage advice "RUN!"