Permanence

If I were an 11-year-old kid wandering around what is now Utah a century ago I could take some basic tools to a nearby rock wall and begin chipping away a picture--what we now call a petroglyph.  Let's say it took me an afternoon.  I'd do it once, and it would last for over 1,000 years.

11-year-olds today may take an afternoon to make and upload a numa-numa song to YouTube.  But how long would that last?  Back it up to an external hard drive?  Temporary.  Put it on a CD or DVD?  Temporary.  Is there anything we're doing today that will last 1,000 years?  Guess I could go grab a chisel.