Has a gorilla killed a human?

Gorillas, despite their immense size and strength, are not aggressive. They are vegetarian except for eating insects and occasionally small rodents.

In 1986, a five-year-old child fell into the gorilla pit in the Channel Islands zoo and was knocked unconscious. The crowd watched in terror as a full-grown male gorilla named Jambo came over… gently and concernedly stroked the boy.

When the kid eventually woke up and started crying, the gorillas sort of ran away in terror. (video)

In 1996, a three-year-old boy climbed a wall at a zoo near Chicago and fell into the gorilla enclosure, suffering a broken hand and a large cut to his face. Nearby was Binti Jua a female who happened to be the niece of Koko—famous for learning (some) sign language. Anyway, as people screamed, Binti walked over and cradled the boy. When she heard the door to the enclosure unlock, she gently laid him down.

In another incident in 1997, a robber in South Africa was running from police through a zoo and decided to hide in the gorilla enclosure (!?). This contained a full-gown male named Max. There was some sort of conflict, which led to the robber shooting Max in the chest and neck. This made Max very angry, and he mauled the robber and seriously injured two police, but didn’t kill anyone. Max was eventually shot with a tranquilizer dart and treated, after which he made a full recovery. The police emphasized that they “carry no grudge against Max”.

More sadly and controversially, in 2016 a three-year-old boy fell into a moat of shallow water in the gorilla enclosure at the Cincinnati Zoo. A male named Harambe went to investigate. Over the next 10 minutes, he carried the boy around, sometimes propping him up or pushing him down, but never really hurt him. The screaming onlookers seemed to agitate and confuse Harambe and he started to “strut”—walk around in a way intended to make him look bigger. Eventually, he carried the boy out of the moat and zoo officials decided to shoot him, killing him instantly. (Tranquilizer darts were not used because they work slowly.) Jane Goodall said that it appeared Harambe was trying to protect the child but also agreed the zoo had “no choice” but to shoot him.

While I can find a few instances of gorillas attacking people, these usually involve provocation, and I couldn’t find a documented case of a gorilla killing someone. (Surely humans and gorillas have coexisted for way too long for this to have never happened.) Some people on the internet claim there are no documented cases, while some people claim it’s just rare, but I couldn’t find any convincing source either way.

Also: Maybe we should look into three-year-old-human-proof fences?

Penguins can dive deep

Shocking news: When animals evolve for millions of years to swim and hunt underwater they get good at swimming underwater!

But still, this impresses me: Gentoo penguins regularly dive to 200 m (656 ft). Emperor penguins regularly do 265 m (870 ft). Researchers found one small female in the McMurdo sound that dived to 535 m (1755 ft) and a penguin in the Auster Islands that dove to 564 m (1850 ft) in a dive that took 21.8 minutes.

Just to give these numbers some context, light usually doesn’t penetrate beneath 200m in the ocean (though it can go as deep as 1000m if the water is very clear). And here are the current world records for human free diving:

• No fins: 102 m
• With fins: 131 m
• With fins and dropping weights: 146 m
• Using a metal sled to go down and air bags to ascend: 214 m + merit badge for insanity

And remember that the penguins aren’t, you know, trying to dive deep. They’re just doing that incidentally because that’s where they can find fish.

Noise location oddity

Here’s something weird I’ve noticed. Say I’m sitting at home and in front of me and on the side is an open window:

Now, say someone behind me outside starts making noise. The wall behind me mostly blocks it, but it easily bounces around and comes in through the window in front of me:

I know that most of the noise is coming through the window, because closing it eliminates 80% of the noise. Yet, it still “sounds like” the noise is coming from behind me. Why?

Here’s the two hypotheses I can come up with:

• Some noise still goes directly through the wall. Perhaps my brain notices that the same pattern is coming from that direction earlier—even if it’s quieter—so it guesses that must be the direction of the source.
• Perhaps I unconsciously “know” where the sound is coming from, and that knowledge finds a way to influence the low-level perception?

Does anyone know? The Wikipedia page on sound localization doesn’t seem to explain this, though I was interested to learn that we unconsciously exploit the acoustic properties of our heads.

Update: Looks like the first hypothesis is right. It’s called the precedence effect and has some interesting uses. (h/t Rudy Richter)

Air quality signal boost

Many people found this blog via my posts on air-quality/air-purifiers/etc. So I wanted to promote Jeff Kaufman’s stuff on this topic, including:

• Testing Air Purifiers: This is how you test performance, by fitting an exponential to a full time-course of data. Famous Product Review Sites should copy this method.
• Ceiling Air Purifier: Surely the craziest design for a DIY air purifier. And perhaps the cheapest, as there’s essentially nothing to buy other than the air filters themselves. I worry a little about extra wear on the fan motor. Still, someone please optimize this design for aesthetics!
• Workday Air Quality Measurements: What happens if you walk around with an air quality meter for a day? (For one thing, you confirm that particle levels in subways are outrageously high.)

A conversational pattern that needs a name

Does anyone else experience this?

You: Is X above Y?
Them: What?
You: IS X ABOVE Y?
Them: What’s X?
You: X is blahblahblah. Is it above Y?
Them: What’s Y?
You: Y is blahblahblah.
Them: Why are you asking?
You: I want to do Z.
Them: But why do X and Y matter?
You: Because if X was below Y and I did Z, then blahblahblah would happen, which would be bad.
Them: Oh, I see, makes sense!
You: …
Them: What?