Lord Kelvin
Formulated the first and second laws of thermodynamics and proposed the absolute temperature scale.
Most quoted
"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be."
— from Popular Lectures and Addresses, Vol. I, 1883
"When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind: it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be."
— from Popular Lectures and Addresses, Vol. I, 1883
"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the stage of a science."
— from Speech, 1889
All quotes by Lord Kelvin (356)
One word characterizes the most strenuous of the efforts for the advancement of science that I have made perseveringly during fifty-five years; that word is failure.
I have not the smallest molecule of doubt that if we had a perfect knowledge of the properties of matter, and of the forces acting between its particles, we should be able to predict the future with absolute certainty.
If you think strongly enough you will be forced by science to the belief in God.
Overwhelmingly strong proofs of intelligent and benevolent design lie around us... The atheistic idea is so nonsensical that I cannot put it into words.
Science is bound by the everlasting law of honour to face fearlessly every problem that can fairly be presented to it.
I am never content until I have constructed a mechanical model of the subject I am studying. If I succeed in making one, I understand the subject. If I cannot make one, I do not understand it.
Mathematics is the only good metaphysics.
I have always felt that the true greatness of a man is to be measured by the extent to which he has been able to serve his fellow men.
The beauty of a scientific theory is its simplicity.
We must not be afraid to make mistakes, for it is through them that we learn.
Science is not only a disciple of reason but also one of romance and passion.
The greatest discovery of all time is that a person can change his future by merely changing his attitude.
There is no such thing as a 'self-made' man. We are all dependent on others.
The more we know, the more we realize how much we don't know.
What is mind? No matter. What is matter? Never mind.
The universe is not only stranger than we imagine, it is stranger than we can imagine.
I am a firm believer in the power of the human spirit.
The true scientist is a man of faith.
The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.
The only limit to our realization of tomorrow will be our doubts of today.
Contemporaries of Lord Kelvin
Other Physicss born within 50 years of Lord Kelvin (1824–1907).