"That's really helpful! Honestly the thing it reminds me of most is video game mechanics, but you probably don't know what those are so it's kind of a useless analogy, sorry. Coming up with good experiments is hard, but the good news is that even an experiment that doesn't teach you what you wanted can teach you something."

(He realizes that if this is real, he's never going to have to write another grant proposal again, and suddenly he's in an even better mood than before.)

"I have an experiment suggestion. Try doing the same motion you did to open the door, while not wanting it to open. Can you do that?"

{okay!}

It does the thing.

The door is not affected.

"Cool. So now we know that either the door is detecting your thoughts, or there's something you did differently without noticing and it depends on small details of what you do instead of just happening every time you touch the door. We didn't know that before; we learned it from doing the experiment. Does that make sense?"

{oh,} it says. {no, is different from that. touched door, didn't open door. open is different thing from touch, but need to touch to open. but open is different thing from want to open, too.}

"You need to touch it to open it? Did you already try opening it without touching it, or is that something you know instinctively?" He has at least three other questions, but unfortunately in-person conversations can't have arbitrary tree structures.

{is like can't put thing without hold thing,} it explains. {the do is not there.}

He attempts to place a wall without holding one, just to be sure. Yup, no wall.

"Okay, cool. So now, I'm wondering what happens if there's something in the way. Try opening the door again while I'm holding the handle stationary?" He suits action to words, preparing to resist some amount of force but also prepared to let go if the door is "stronger" than him.

{okay!}

The spirit touches the door, and the handle turns. It is definitely stronger than Bruce. That door is going to open regardless of his opinion on the matter.

That was in Bruce's hypothesis space, so he doesn't get hurt when it pulls itself out of his hand, but it's still impressive. Now he's wondering what would happen if two spirits opened two doors that had been set up one right in front of the other so they collided. Possibly the position grid thing isn't dense enough to make that possible, and anyway he only knows the one spirit.

"Cool!" he says. "Can you think of any other things to do with the door where you don't know for sure what will happen?" 

It thinks about this.

{when spirit open door, door close soon. don't know if same when friend open.}

"Okay, let's try that." He shuts the door and opens it again, trying to leave it at the same angle it tends to go to when the spirit opens it.

It stays open for five seconds, then closes.

Bruce doesn't have a stopwatch, but he can get at least a pretty close comparison of the timing for when he opens the door and when the spirit does it. Do they match?

Yep!

"Okay, so the door closing works the same for both of us. I have a couple experiment ideas but if you have any others let's do those first. Both so you get practice and because you know more about this place and will probably have better ideas than me."

It considers for a moment.

{spirit open door only one amount. friend open door different amounts?}

"Yes! At least, I think so. Time to test the hypothesis!" He tries opening the door just a crack. If that works, he shuts it and tries opening it as wide as it will go.

Both of these attempts succeed!

When he opens the door fully, there's a slight click like something snapping into place, and a slight resistance to being closed again.

"Ooh, did you hear that?" Bruce says when he notices the click and the resistance. "And it was a little harder to close again. IIIII have a hypothesis, can you guess what it is? Or possibly you already know. But guess anyway?" A door that potentially props itself open when you open it all the way is not that objectively interesting and he feels kind of silly for being excited about it, but here everything is new and full of potential coolness.

{door stay open?} it guesses, bouncing.

"That's my guess too!" Time to test it! Push, release, one Mississippi two Mississippi three Mississippi . . . 

Door stay open!

Bruce waits until twenty Mississippi to call it. "We made a successful prediction! High five!" He holds out his hand low enough that the spirit can high-five him, at least if they're familiar with the concept.

The spirit boops his hand with a tiny pointy arm.

What an adorable being. Bruce shuts the door again and asks, "Can you try opening it all the way, or do you not have the option?"