# Aliens have landed!

Aliens from planet Stirwet have landed on earth! Being hyper-intelligent and possessing superior technology, they immediately took over.

After having a quick look around, they found humans and apes (which they could not tell apart) to be the most interesting species.

(I don't mean they found us interesting to talk to, they just like looking at us and collecting us, as a fetish almost)

Before they began to collect the creatures they fancied and put them in jars of formalin for preservation, they used their superior technology to detect and classify all the human and ape creatures on the planet.

The classifier is an incredibly advanced piece of technology, which creates signals that can pass through the earth and this way find all the creatures on it, and classify them according to their Stirwet type.

Only the classifier kept glitching.

You see, the classifier should always return to the individual's base level. It can change for a short amount of time, because some property of the individual changes, but because the individual has a base level it should always return to that.

Here, an individual could be consistently classified as, for example, 2, but after an hour gets classified as 0, with equal stability. (Am I making this clear enough? I know it's hard to imagine a classifier not working properly).

So anyway, each individual was classified, almost always with 0 or 2, with small (as expected) quick glitches of 1, 3 and 4. Again, to clarify, no rules are broken if the classifier gives you a different score for a short amount of time, as long as you go back to your base classification. But is it 0 or 2? Why can't these creatures make up their minds?

To help the aliens take over and bring us to their world as decorations and toys, we need to figure out how we're messing with the classifier, and then stop doing it. But first we need to ask:

What does the classifier do?

Hints

The numbers are not arbitrary

• Does the long-term base classification typically alter over time for a specific individual? If so, then @Vaekor's answer looks good: 0 weight-bearing limbs when lying down, 2 when standing. Or is a specific individual more or less permanently classified either as a 0 or a 2, with occasional short changes to other values? Commented Nov 7, 2021 at 12:46
• Also "Stirwet" anagrams to "Twister", which kind of relates to number of extremeties on the ground? Though yeah, not sure I have a base number for that idea given my waking and sleeping. Commented Nov 7, 2021 at 13:40

Is it

Number of limbs touching the ground? 2 when standing, 0 when (eg) lying on a bed, 1 sometimes when walking and 3/4 if you’re crawling? Not sure if it fits perfectly with the rest of the story but worth a shot.

• I find it odd that this answer was chosen as correct when I included it as one of two possibilities in my answer. Commented Nov 8, 2021 at 22:15
• Yes agreed. And after I quoted your answer, too, in my comment on the question. Commented Nov 9, 2021 at 9:11

Edit: With the new information, my two best guesses both come out creepy... Focusing on "0" and "2" (and sometimes 1 briefly), I get:

Number of eyes open: 0 when asleep, 2 when awake, 1 briefly when winking, 0 briefly when blinking, 3 when.... 3 eyes?? I mean, maybe the classifier confuses the mouth with an eye, but then the classifier has much deeper problems than I thought.

Focusing on the range "0-3", I get:

Number of limbs used in walking: Sometimes we aren't walking, sometimes we walk on two limbs, sometimes we just use 1 to nudge something, sometimes gorillas use 3 while carrying something and running, I guess we might use three if we bend down to pick something up while walking, but gorillas could also use 4... why isn't the classifier picking that up?

Of course, my solutions ignore:

people who may have been born with fewer limbs, had an accident and lost an eye/limb... but the story said "most", so I think I'm in the clear there.

I realize that lateral thinking puzzles are meant to be vague in some areas so as not to give away the problem at hand, but I feel like this could be almost anything. If the classifier is honestly getting 0 and 2 on the same person, it could be:

Anything that involves a cycle taking more than an hour, including being asleep/awake, hungry/not hungry, dry/wet (from showers, etc), standing up/sitting down/laying down, all of which have intermediate states that could register as 1,3,or whatever.

If the classifier is getting 0 on some people and 2 on other people, and they just don't realize it's not the same person (after all, if they can't tell us from gorillas, can they tell Chad from Steve with any reliability?), it could be literally any source of (mostly) binary difference, such as:

Gender, handedness, facial hair (all of which also have intermediate states that could register 1,3,or whatever)

It's also possible, given their confusion, that:

If they can't tell individuals apart, 0 is human and 2 is gorilla (or vice versa)

For that matter, if the classifier has specific preference ranges, it could be literally anything:

Height, skin tone, hair color, ability to taste bitterness, etc

• I see what you mean. Made some edits Commented Nov 6, 2021 at 19:14