Tools have two main purposes: to help us sense and to help us do. In science, we use tools to help us sense. Science advances in two ways: building directly on the knowledge of previous scientific findings, and using tools to extend our senses further.

How easy would science be if we had unlimited sensory ability?

Imagine we could observe a cell functioning in perfect resolution, in any sense of the word “observe” that we want, with unlimited control over time. How fast could biology advance? I think it would be pretty straightforward to not only learn how all the parts interact, but to identify causes of diseases and develop treatments. We would still need to conduct experiments (or at least simulations), but they would constitute somewhat straightforward paths towards answers and fixes.

Most scientific effort is therefore spent in finding ways to work around our sensory limits and in extending our sensory abilities. Humans began with the innate ability to sense things at particular scales: millimeters to kilometers, milliseconds to years, and rough concentrations of a smattering of chemicals in the air (smell) and in other substances (taste). Over time, we have steadily extended our senses.

Causes of unknowns

Our sensory limitations in science boil down to three issues involving space and time: things being too small, too fast, or too slow. Some mysteries of the universe are quite large, but are very far away and cannot be observed without a powerful telescope, so from the perspective of humans on Earth I’m counting those as “too small”.

Diagram of sensory limits and

The nature of light was unknown for so long because photons are too fast and too small. People didn’t realize the ground below them was moving; the plate tectonic theory was only widely accepted in the last century because the process is too slow to notice by eye. And so on.

The study of biology is dominated by overcoming smallness. If cells and their machinery were large enough, we could stick sensors into them and see what’s happening. Who needs X-ray crystallography when you can look at a protein the size of a crystal ball? And without smallness, the fastness of biochemical activity could be easily overcome with current technology.

Holding a protein and saying "Well, guess I solved the

Evolutionary biology, on the other hand, is mostly a matter of dealing with slowness. If we could induce evolution quickly in any experiment, and simulate evolution countless times, we could infer life’s phylogeny. However, without the smallness issue in biology, evolutionary biology would be less useful. There wouldn’t be much need to compare related organisms and genes when we could easily measure the properties of each gene, protein, and organism directly.

Motivation for biological research

If sensing smaller things better is the key to biology, should biologists pick the low-hanging fruit and then step aside to let engineers and chemists extend our senses further? No, I think there is value in doing things the hard way, i.e., devising clever experiments and analyses to scrape insight from fuzzy information. It’s part of a feedback loop with the sensory development. No one would have bothered developing DNA sequencing methods if clever experiments hadn’t determined that DNA molecules stored genetic information.

I do find it useful (if not tantalizing) to think about how I would study something using perfect senses. It helps remind me that the things we study aren’t all that complex. We just need to use clever methods to overcome our sensory limitations.