When one door closes, another opens; but we often look so long and so regretfully upon the closed door that we do not see the one which has opened for us.

I thought that Helmholtz had done it... and that my failure was due only to my ignorance of electricity. It was a valuable blunder... If I had been able to read German in those days, I might never have commenced my experiments!

The photophone is the greatest invention I have ever made, greater than the telephone.

Mr. Watson, come here — I want to see you.

I never did anything by accident, nor did any of my inventions come by accident; they came by work.

-- Thomas Edison

The more I practice, the luckier I get.

-- Ben Hogan

In the first year of Yuanxing [105 CE], he presented it to the throne. The Emperor praised his ability, and from that time on everyone adopted it; thus the world called it 'Marquis Cai's paper.'

-- Cai Lun

Isn't it astonishing that all these secrets have been preserved for so many years just so we could discover them!

-- Wilbur

Mr. Watson, come here — I want to see you.

-- Born in Edinburgh in 1847

I suppose you could say that the moment I saw those lines I had the basic idea for television.

-- Philo Farnsworth