[Do not] put too much confidence in experimental results until they have been confirmed by theory.

[Do not] put too much confidence in experimental results until they have been confirmed by theory.

It is the theory that decides what can be observed

It is the theory that decides what can be observed

You have to know you can first. How comes later.

You have to know you can first. How comes later.

Conjecture as to things useful, is good; but conjecture as to what it would be useless to know, is very read more

Conjecture as to things useful, is good; but conjecture as to what it would be useless to know, is very idle.

Science is organized common sense where many a beautiful theory was killed by an ugly fact.

Science is organized common sense where many a beautiful theory was killed by an ugly fact.

A young boy is a theory, an old man is a fact.

A young boy is a theory, an old man is a fact.

If the facts don't fit the theory, change the facts.

If the facts don't fit the theory, change the facts.

Many things difficult to design prove easy to performance.

Many things difficult to design prove easy to performance.

I never once made a discovery ... I speak without exaggeration that I have constructed three thousand different theories in read more

I never once made a discovery ... I speak without exaggeration that I have constructed three thousand different theories in connection with the electric light ... Yet in only two cases did my experiments prove the truth of my theory.