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)
I have been much occupied with the question of the age of the earth.
I am quite sure that the earth is not a molten mass.
I have a firm faith in the conservation of energy.
The more I study nature, the more I am amazed at the Creator.
I am very anxious to get a good working theory of the ether.
I have been thinking much about the nature of light.
I am convinced that the wave theory of light is correct.
I have been much interested in the problem of submarine telegraphy.
The Atlantic cable is a great triumph of engineering.
I am very hopeful about the future of electrical engineering.
I have been much occupied with the question of absolute temperature.
I am quite satisfied that there is an absolute zero of temperature.
I have been much interested in the theory of heat.
I am convinced that heat is a form of motion.
I have been much impressed by the beauty of mathematical physics.
I am always striving for greater precision in my measurements.
I have a great admiration for Faraday's work.
I am very fond of experimenting.
I believe that the ultimate aim of all science is to reduce the phenomena of nature to mechanical principles.
I am much occupied with the question of the age of the sun.
Contemporaries of Lord Kelvin
Other Physicss born within 50 years of Lord Kelvin (1824–1907).