Communicating with future generations: Sandia National Laboratories has asked a team of outside experts to devise a marking system for nuclear waste disposal sites that can last for 10,000 years. The system has to be robust, so that even if future generations lose knowledge of the English language or advanced industrial technology, they can still understand the importance of avoiding this area. It should also be designed in such a way as to discourage vandalism or other attempts to destroy or remove the markers. Hence, the markers must somehow convey the following:

* This place is a message... and part of a system of messages... pay attention to it!
* Sending this message was important to us. We considered ourselves to be a powerful culture.
* This place is not a place of honor... no highly esteemed deed is commemorated here... nothing valued is here.
* What is here is dangerous and repulsive to us. This message is a warning about danger.
* The danger is in a particular location... it increases toward a center... the center of danger is here... of a particular size and shape, and below us.
* The danger is still present, in your time, as it was in ours.
* The danger is to the body, and it can kill.
* The form of the danger is an emanation of energy.
* The danger is unleashed only if you substantially disturb this place physically. This place is best shunned and left uninhabited.

This is a fascinating and non-trivial problem, and some of their proposed solutions are very interesting, such as:

* Landscape of Thorns
* Spike Field
* Spikes Bursting Through Grid
* Leaning Stone Spikes
* Menacing Earthworks
* Forbidding Blocks

It's worth reading the whole thing. (Via Linkfilter.)