What can we measure, and what can we not measure? The answers have important implications.
This may seem like a blinding flash of the obvious, but it dawned upon me a while back that science is about what we can measure. That may put me in the finals for some kind of slow learning award, but I had never thought about it in quite that way. I had always thought of science as this marvelous story of heroic discovery—Newton, Einstein, Galileo, Pauling, Hawking, etc. I thought of the development of science as the story of big ideas about motion, mass, light, gravity and so forth.
So here is a little thought experiment. If Einstein had proposed his theories of special and general relativity five hundred years ago, he would have been wrong by all the standards of scientific knowledge. Not ahead of his time, but wrong. Why wrong? His ideas would have been dismissed because there was nothing for them to explain. None of the things that Einstein talked about (the speed of light and tiny changes in the passage of time, for example) could be measured. Actually, he could not have come up with his theories because he would not have been able to do the math. Calculus had not been invented. His theories were literally unthinkable.
When you think about it, the improvements in our ability to measure stuff is stunning. We humans can now measure the difference in weight of the same brick held above your head or at your feet. It is measurably heavier at your feet because it is closer to the center of the earth. We can measure distances down to septillionth of a meter. Time, well, space-time really, is measured by how long it takes light to cross the tiniest distance. This is way, way beyond splitting hairs. It is mind boggling.
And you can’t find neutrinos or gravitational waves or even make the gps on your smart phone work without this ability to measure precisely.
But what about things that do not lend themselves to measurement? Think of two musicians playing the same piece of music. Both play it note perfect. One performance leaves us cold and unaffected, the other moves us profoundly. What is the difference? The music is not the notes. We can measure whether the correct notes were played. Measuring the quality of the performance is elusive—and yet we instantly sense the difference between good and dull playing.
I have one more quick example that comes from my long standing interest in listening to music on “hi fi” equipment. We can measure the harmonic distortion of two amplifiers. However, the distortion measurement tells us very little about how it sounds. Often an amplifier with higher measured distortion sounds obviously better than another with lower measured distortion. It is easy to measure the wrong thing, or to measure one aspect of something and delude ourselves into thinking we have measured the whole thing. The experience of listening to music is complex. The harmonic distortion of an amplifier is only a small part of it.
Measurement is important, and not just for scientists. Think of how we rely upon blood tests, x-rays and MRIs. Advances in measurement have opened new worlds. Not long ago we had no way of knowing about the infrared, the ultraviolet, radio waves, microbes and galaxies.
And yet there is a perverse quality to measurement. Think of how IQ test results have been misused. Consider pseudo scientific measures of phrenology (measuring bumps on a skull). It is easy to fall in love with what we can measure and to think that what we can measure defines what is real.
Many of the things that give life meaning defy measurement: beauty, love, peace, joy.
Sometimes the right measurement is the digital readout on a sophisticated instrument. Sometimes the right measurement is how something makes you feel.
Science is about what is, not about so what.