The Thaumotrope

Begin with two things.

The thaumotrope is a small optical toy: a disc with a picture on each face and strings at its edges. Turn it quickly and the separate pictures can appear together. In the familiar bird-and-cage example, the bird seems to occupy a space that is drawn on the other side of the paper.

I keep returning to this object because its construction remains so available. I can see the string. I can turn over the paper. I can account for every mark and still find something in the experience that the inventory of marks does not describe.

The phrase “a bird in a cage” already contains a little story. A creature has been enclosed. But inspect the surfaces separately: one contains a bird, the other an empty cage. Their placement makes the enclosure possible. The relation arrives through an act.

Choose Two sides. Then Turn by hand. Take the disc through half a turn and look at what each face actually contains.

That small exercise is where I want to begin. Before asking the toy to carry an argument about consciousness or virtual reality, I want to be able to turn it over.

The hand enters the picture.

In the book, I wrote:

The thing you came to see—the bird inside the cage—exists only in the spinning. It is produced by neither image alone. It lives in the verb, not the noun.

The verb matters to me. A thaumotrope has to be set in motion. With a paper toy, my fingers turn the strings. Here, holding the control adds motion to the disc; releasing it lets the motion decay. The screen gives that action a visible consequence.

Hold to wind, then let go. Watch the disc slow down. Spin once gives it a turn with a single press. You can stop it at any time.

I can also choose Overlay and hold both drawings still. That image contains the same marks, but it asks something different of me. I no longer have to sustain the action. I can study what the movement made briefly available.

The difference between sustaining and inspecting is part of the essay. Both are useful ways of knowing an object. The still image gives me time to look closely; the moving one makes me attend to how the image is being maintained.

Who put the bird inside?

The bird fits because someone drew it to fit. Its scale, its position, the width of the cage: these decisions are already waiting inside the trick. I have composed the conditions under which you are likely to see an enclosure.

Choose Overlay and open Change the relationship. Move the bird toward the edge. Make it larger or smaller. Leave the cage where it is.

As the bird passes across the bars, “inside” becomes less certain. The outline can seem to hold a creature, cut through it, or sit beside it. The two source drawings remain recognizable while their relation changes.

I want that decision to be available to you. A toy that accepts only the arrangement I had in mind would tell you more about my preferred answer than about the possibilities of the two images.

Try the moon with the cage. Or the hand with the sea. The same motion can bring together marks that suggest a landscape, an impossible enclosure, or nothing you particularly want to name. You are allowed to leave a pairing unresolved.

Four ways of meeting.

The bird and cage offer a relation of containment. The moon and sea offer a scene. The moon does not have to fit inside the water; an interval between them gives the image room to become a landscape. Moving it changes the composition without changing the names of either thing.

The hand and strings bring me closer to the reason this toy found its way into my writing. Years of playing the banjo taught me how much of knowing an instrument happens in the relation between an intention and a trained movement. My fingers can carry patterns that I would struggle to reconstruct as a sequence of instructions.

The drawing cannot give you that knowledge. It offers a place to think about contact: where a finger meets a string, how a small displacement changes the gesture, how incomplete each image looks without something to act upon or be acted upon.

Try each disc. Then put Here and there in the still overlay. Raise or lower the first word until both become readable.

These words resist a comfortable fusion. In the same place, their letters interfere. Separating them restores something that overlap obscured. A meeting can produce an image; it can also make a message difficult to read.

I need that difficulty here. If every pairing resolved into a pleasing whole, the disc would quietly insist that bringing things together always improves them. The words give us another possibility: a relationship that needs some distance.

The screen has a hand in it.

There is a further construction to inspect. A paper disc and this screen do different things. On the entrance page, I used a finished bird-in-cage image that appeared as the apparent speed increased. The software had already been given the result.

For this table, the overlap is assembled from the two drawings you are editing. The pale ink belongs to the first face and the gray ink to the second. Your changes to position, size, and selection remain in the combined image.

As the disc gathers speed, the visible turning eases into that overlap. I have chosen when this happens so the drawing stays readable without rapid flashing. The transition is a designed representation of the toy’s effect. It does not measure your vision or establish the speed at which a physical disc would appear to fuse for you.

The still overlay makes that decision explicit. It lets you inspect exactly what has been put together. If your device requests reduced motion, the table begins there; the separate faces and manual turn remain available.

The construction belongs in the experience. Knowing how I made the image gives you another way to read it—and another point at which to disagree with the analogy.

What I ask the toy to carry.

In Carmen et Error, I keep finding new faces on this disc. Past and future. Intention and muscle. The room in which I am standing and the virtual world I am attending to.

With time, the analogy helps me think about a melody. What I have just heard remains active in my listening; what I expect to hear next changes the note sounding now. A sequence becomes something I can inhabit through the relation among those moments.

With virtual reality, it helps me describe the simultaneous demands of two places. My feet remain on a floor. My attention reaches into a rendered world. The body that has to balance, reach, and turn keeps participating in what that world can mean.

These are readings I bring to the toy. Spinning two pictures does not settle what time is, explain consciousness, or prove a theory of presence. It gives me an object with which to keep the questions active. I can point to the sides, the motion, and the hand; I can ask what each contributes.

That is why I want more than one disc. Each new pairing tests how far the figure can travel. Some relations become clearer in the overlap. Others ask me to slow down, separate the images, and look again.

Let it come to rest.

Return to the disc you made. Give it one last turn, then let it stop.

The marks are still there. So is the possibility of putting them into relation again. But the activity has ended, and I can remember an image that I am no longer looking at.

The book follows that difference into places, instruments, rituals, and worlds people try to build together. What has to be sustained? Who does the sustaining? What remains in a person after an experience ends?

I built you a thaumotrope and handed you the string. The reading is the presence.

The sentence returns the object to your hands. You can keep turning it, change what is on its faces, or put it down.

Continue into The Spinning Disc — A Manifesto for Presence.