Clarke defines the adjective 'elderly' as :"In physics, mathematics and astronautics it means over thirty; in other disciplines, senile decay is sometimes postponed to the forties. There are of course, glorious exceptions; but as every researcher just out of college knows, scientists of over fifty are good for nothing but board meetings, and should at all costs be kept out of the laboratory". (in Profiles of the Future.)
"The only way of discovering the limits of the possible is to venture a little way past them into the impossible."
"Any sufficiently advanced technology is indistinguishable from magic."
Though he wrote after the laws that "Since three laws was sufficient for both the Isaacs - Newton and Asimov - I have decided to stop here", he continued to write laws, as we can see in the Appendix 2 of The Odissey File where he states the Clarke's 69th Law:
"Reading computer manuals without the hardware is as frustrating as reading sex manuals without the software."
Other laws and principles