The "This Place is not a Place of Honor" article over at Damn Interesting brings up the problem of marking our nuclear waste so that it will be identifiable as dangerous for people 10,000 years in the future.
The first problem is that our "nuclear" symbol could be mis-construed as an angel.
Simple solution: rotate the symbol 45 degrees.
The overall problem remains; how do we warn cultures 10,000 years in the future of danger? I vote for the skull. The skull has been used sucessfully by nature for thousands of years to signal danger/death to humans. We don't even need the crossbones. You put enough skull diagrams in the area and most will get the point.
The whole problem makes me wonder, though. Every time this "how do we warn our children 10,000 years in the future of the dangers of radiation" thing pops up, we start thinking that the future very well may be populated with cave-men like morons. Could the fact that this assumption keeps coming up may be a warning to us that perhaps, deep down, we're afraid all this nuclear waste isn't going to be good for future generations? Strange that we're so obsessed with warning the future when it is the present that should be heeding them them most.