For thousands of years, our species has been steadily building up information in ways unlike any other species known to us. It is the key to our success thus far. Information is not necessarily human-made, of course, any state of matter that is not utterly random has some information encoded in it.
It was fascinating to watch my geologist brother take a careful hacksaw to rock after rock, cutting each piece to size for the experiments, analyzing the magnetic properties and building a picture of how sediments formed layers of particles with the magnetic polarity of the earth embedded in every layer, forming a timeline. Even rocks tell stories to those who are listening!
Then I heard this story about Joe Ossanna and one of the programs that he authored back in 1970s: troff. If you haven't heard of it, it's alright, but if you're running a UNIX clone, you can try typing "troff -h" in your terminal.
What is special about this program, is that it was built on now-arcane systems, not many know how the program works, but since it can be patched to fix its assumptions, the code continues to work mostly unchanged from what was written by Mr. Ossanna, to this date (http://troff.org/history.html).
If the command displayed some text and exited, cool - you just confirmed you too have a bunch of computer files that hold the information - the order of things that Joe Ossanna imagined, typed into a computer and shared with others.
You just summoned the ghost of Joe Ossanna!
As your tapped the keys and hit enter, code written by many brilliant minds of our species churned the bit-gears to make the magic of our generation's technology come alive.
How fascinating to realize, that not only have machines always been a part of us - we are made out of molecular machines after all, but also that we've been living as fragments of our ideas, strung together by compilers within our computers.
That seemingly mundane code you write and maintain can be your little ghost after you're gone - still around, ticking away, helping future generations get their work done... what would you make?