A mathematician and an engineer attend a lecture by a physicist.
The topic concerns Kulza-Klein theories involving physical
process that occur in spaces with dimensions of 9, 12 and even
The mathematician is sitting, clearly enjoying the lecture, while
the engineer is frowning and looking generally confused and
puzzled. By the end the engineer has a terrible headache. At the
end, the mathematician comments about the wonderful lecture.
The engineer says "How do you understand this stuff?"
Mathematician: "I just visualize the process."
Engineer: "How can you visualize something that occurs in
Mathematician: "Easy, first visualize it in N-dimensional
space, then let N go to 9."