version of:   May 16, 2004

Chapter 8: Null Experiments

The main point in building a laboratory is to prevent disturbances, thereby creating a quiet and controlled environment in which to repeat the same experiment many times, and compare the results with that of other experiments, that you also repeat many times. Each experiment will still suffer from random influences, `noise' of various types, either intrinsic to the experiment or coming from the outside. However, even a little care in minimizing this noise goes a long way toward creating a better environment for experimentation.

Experiment 1.2: Do Nothing

Find a comfortable place somewhere to sit down, in a quiet surrounding. A closed room where you are alone would be fine, or if you can find a quiet spot outdoors, that would also be a good choice. You can do this experiment while standing or lying down, but to start with, it would be best just to sit, on a chair or a rock or just on the ground.

Take a few minutes to relax, letting go of the immediate concerns of the day. Take a few deep breaths, stretch your body a few times in whatever way you like, like a cat yawning, ready to get up. You may want to shake yourself loose a few times as well, like a jogger warming up, ready to start running.

The difference is, you will get ready to do nothing. After your first few minutes of warming up exercises, you just drop everything and you just sit there. That's it. Nothing else.

Of course, you'll keep breathing, and most likely, thoughts will keep coming up. Let your breathing be natural, and also let your thoughts come up as they want. Don't try to suppress them or tame them in any way. Just observe them and don't do anything with them. Let them be, moving as they want, just like you let your breath move as it wants. They can all do what they want; your only job in this experiment is to do nothing.

Out of the Box

Now this looks like a strange experiment. being asked to do nothing. If someone would ask us to do nothing, without any further instructions, we would probably start by imagining what it would be like to do nothing, before actually doing it. The very idea of just doing nothing would seem so silly and boring that it is quite likely that we wouldn't even really try.

And even if someone would convince us to try, we are likely to find ourselves in a little box that we have constructed, namely our imagination of what doing nothing would be like. In other words, what we would think of as doing nothing, might actually wind up as working hard to create this little boring box that we think corresponds to to this doing nothing. Our lab report would then mirror our initial conviction, measuring as output just what we put in.

This is the main reason that I have given somewhat more detailed instructions, including both relaxation and warming up aspects, to minimize the chance that you would fall into the trap of creating an artificially constructed `doing nothing' situation. A further way of minimizing that chance is to write a lab report, as discussed in the previous chapter.

No Box

For starters, I suggest you do this experiment three times, in different settings. If you write a lab report after each experiment, it will be interesting to compare those three sets of notes, both for the similarities and the differences that you will find. The fact that there are differences already points to something more going on than just `nothing'.

If you look carefully, at least some of the similarities might be recognizable as a little bit of left-over box building that you have done to manufacture a do-nothing situation. Seemingly random differences may reflect the situation and your mood at the time of the experiment, but persistent patterns could be a sign that you're systematically still doing something.

Now if you can drop that activity, you can really open up! Note that you don't have to step out of the box that you were just creating, you only have to stop working so hard at creating the box. That's all.

An Empty Lab

In contrast to experiment 1.1, it is hard to predict what someone will find when first doing experiment 1.2. Since the express purpose is to do nothing, whatever is left after subtracting the most obvious part of our normal doing tendencies depends very much upon the individual.

Yet whatever the individual's residual tendencies may be, you can be sure that those tendencies will show up in other experiments as well, in some way or another. So it is a very good idea to get acquainted with them, and to get acquainted with them rather well.

After doing this experiment several times, not only will you get a feeling for what a typical doing-nothing situation will be like for you, equally importantly, you will get a sense of the range of variations. It will be different in the morning, or the afternoon, or the evening. It will be different just before or after a meal. It will be influenced quite a bit both by the physical surrounding as well as by your mood and concerns of that moment.

By doing these experiments you are calibrating the laboratory of your life. If you are serious about using your life as a laboratory, it is well worth your while to start early on by getting acquainted with the condition of the laboratory in the absence of particular tools and experiments, so that you can take that condition into account later, when you will get into more detailed measurements.


In science, the most accurate experiments are so-called null experiments. The idea behind a null experiment is that you perform two measurements simultaneously in such a way that there would be no difference if there would be no signal of the type you are interested in. The simplest example of a null measurement is an old-fashion pair of scales to measure the weight of an object.

Back in the days before electronic scales, if you were to buy a pound of apples in a fruit store, the person behind the counter would first put a metal weight of exactly one pound on one of the scales of a balance, and then add apples to the other scale, until the two scales would be in equilibrium.

If the person would be trying to get very close to exactly one pound, he or she could even replace a few apples. If the total weight would be a bit over one pound, one of the larger apples could be replaced by a smaller apple, and the other way around. Even a single gram of difference would easily show up on a good balance, by the scales moving to one side or another. Although one gram is less than a quarter of a percent of the total weight of a pound, because the two weights almost cancel the sign of the difference, whether it is positive or negative, is still obvious.

In contrast with an electronic scale, which must be precisely calibrated in order to make sure that at least the first three digits of the measured value are accurate, all that is required from a traditional balance is that it truthfully tells you "heavier" or "lighter", of the left side with respect to the right side. That's all!

Sky Subtraction

This trick of getting a lot of accuracy for free by pretending to measure nothing is widespread throughout all of science. You could say that it lies at the basis of any type of lab experiment. Just to give one example from my own field of astrophysics, we have a procedure called sky subtraction.

If you make a picture of a galaxy with a telescope, whether it is a backyard amateur telescope with a CCD camera or one of the world's largest telescopes in Hawaii or in Chile, the first thing you do after making the picture is to do a sky subtraction. The idea is straightforward: you compare your picture of a galaxy with a picture of a piece of blank sky, where there are no bright stars or galaxies at all.

By subtracting the measured intensity of each pixel in the empty sky picture from the corresponding pixels of your galaxy picture, you effectively remove the contribution from the night sky, the light that is scattered in the Earth atmosphere. And the better your procedure of sky subtraction, the cleaner your final picture will be, and the more you will be able to see fine detail of the galaxy itself.

If the amount and distribution of background light varies in time, for example because the lights from a nearby city are brighter in the evening than in the early morning, you may have to repeatedly take empty sky pictures, in order to perform the correct subtraction for the pictures of real galaxies. This may seem like a waste of telescope time, but this procedure is absolutely essential: not calibrating the galaxy pictures would be the real waste of time, since then none of the results would have any quantitative meaning.


In our case we are still far from measuring anything in precise quantitative ways. Our first steps toward a science that takes the subject seriously is as yet far removed for precision measurements of the weight of apples or the shape of the spiral arms of galaxies. And this is not surprising: it took almost four hundred years, from Galileo's discovery of the moons of Jupiter to the invention of the procedure of sky subtractions that is now routine used when taking snapshots of those very same moons.

Even so, the whole point of our exploration is to move toward such a new kind of science. And in order to have the best possible results, we may as well try to be as careful as we can, right from the beginning. This is the reason that I have introduced the do-nothing experiment above. It can serve as a kind of `blank sky' observation.

During the various other experiments that we will engage in, it will be a good idea to come back occasionally to the experiment described above. Although we do not have a procedure that can subtract two sets of experiences in the same quantitative way as astronomers can subtract two digital photographs, we can at least do something in that direction.

For example, we can compare our lab notes of `blank sky' observations with the notes we took during specific other experiments. Or we can do two experiments side-by-side: perhaps first a minute of do-nothing observation, immediately followed by a specific experiment for however many minutes we like, and then one more minute of do-nothing observation. By sandwiching the real experiment between those calibration ones, we can make the perceived difference directly part of our report.


Apart from all these methodological considerations, there is yet another very simple reason to perform do-nothing experiments. It's good for you! In addition to its primary goal to prevent experimental errors, these experiments may be the best type of preventive medicine that you can find in a hectic society.

The pace of modern life is so fast, and our time is so filled up with chores and obligations, that it is easy to forget what it is like to just do nothing for a while. This may sound strange, but when we look at our activities throughout a typical day or week, we won't find much really open time, time that is not devoted to activities.

If we don't work, at home or at the office or wherever it may be, we may be engaged in all kinds of active relaxation, whether it is watching a movie or going for a walk or having just a chat with someone. In all these cases, we are still doing something in particular. Sitting still and doing nothing is just not done, by and large, in our society -- or at least much less so than it used to be.

Since this experiment has definite health benefits as side effects, it is a good idea to include your feelings of well being, or not-so-well-being, in your lab report when you perform your blank-sky experiments. That way, you can find out over time which settings and timings for these experiments seem to benefit you the most.

Site Selection

Even when you perform these do-nothing experiments many times, you will probably find that you are never doing nothing. But that is fine, since doing nothing is not the point. Rather, the aim is to not get engaged in any conscious project of doing something. It is just like the empty sky pictures, which are never empty: if they were truly empty, you wouldn't have to take them and you wouldn't have to subtract them from the intentional pictures.

The point of gently trying to do nothing is to become aware of what you, or your mind, or your cognitive apparatus, however you want to label it, is doing when you are not trying to do anything. It is really a way of getting to know yourself, on a very basic level. And that knowledge can be put to good use.

When astronomers look for a site to build a new telescope, one criterion is for the sky to be as dark as possible. Taking empty sky pictures at different sites and comparing them is part of the selection process. Similarly, we can experiment with different circumstances for our doing-nothing experiments. In that way, we can select some of the best `sites' (places, times, situations) for our future experiments.

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