Help! i need ideas for objects that represent knowledge?

Question:

Help! i need ideas for objects that represent knowledge?

I am currently doing an art project that is looking at knowledge and could do with some ideas as to what objects could symbolise this.
Anyone any ideas?

Best Answer - Chosen by Asker:

Here are some things that I picture in my head when I hear the word knowledge:
Open Book
Question mark
Apple
Tree with books as leaves
Binary numbers
Einstein or any famous philosopher
The brain
A computer
A teacher with a student
a light bulb above a persons head

I hope these help you out.