I am thinking about a planet on which gorilla-like people live in. Gorilla-shaped, walking on their knuckles, but with the capability of complex speech and a slightly more humanoid face (possessing a slight chin and a forehead, still having something more similar to a gorilla teeth structure than a human teeth structure. Their noses are still the silly heart shape and their eyebrow bones being less protruding than a regular gorilla's.)

However, they are huge, reaching about one or two thousand feet (0.3km-0.6km) in height at adulthood.

I assume the land would be entirely untouched since they would live on the necessities and have what we would probably call primitive communities (they are as smart [if not smarter] than humans, they just enjoy the simpler life as they are most likely the strongest thing around if not the biggest).

  • I assume low gravity is a must.
  • I do know about the infamous square cube law.

Question: What kind of gravity and shape would a planet for giant gorilla-like species have?

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    $\begingroup$ Thousand feet tall? I suppose the gravity should be very low or they should live partly in water so that the water carries most of the weight. Otherwise square-cube law will hit them hard. en.wikipedia.org/wiki/Square%E2%80%93cube_law#Biomechanics $\endgroup$ Sep 21 at 14:32
  • $\begingroup$ Yea, I was thinking low gravity because of the infamous square cube law as I started scavenging through giant-related questions after posting this, tysm! $\endgroup$
    – nunchucks
    Sep 21 at 14:34
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    $\begingroup$ Nerve conduction speeds (on the order of 100 of meters per second) might be an issue when controlling limbs that are several hundred meters away from the brain. When a human trips over something, they can react within hundredths of a second. When a 600m-tall gorilla trips on something, they won't even notice until several seconds later, and it'll be another several seconds before they can move their leg to react. I'd think the creature would have to operate in "slow motion" to remain coordinated. $\endgroup$ Sep 21 at 15:20
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    $\begingroup$ The problem with that is the help center states, "All subjective questions are expected to be constructive. What does that mean? Constructive subjective questions ... are more than just mindless social fun." We're happy to entertain questions of idle curiosity, but we do expect people to be serious enough to treat all the volunteers with basic respect. If this is a flight of fancy, tag it properly and think through what you're really trying to achieve. It might be mindless social fun to you, but it cannot be what you present to us. $\endgroup$
    – JBH
    Sep 21 at 15:52
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    $\begingroup$ @JBH Im sorry I don't understand, I am curious about what I asked and it's not just a flight of fancy, I'm simply saying I don't expect to be like super accurate just a tentative stuff to make it fun but believable 😭 sorry if im not good at phrasing stuff english isnt my first language and im autistic 💀/gen $\endgroup$
    – nunchucks
    Sep 21 at 16:26

3 Answers 3


They live in a dense planetary ring

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In general, a body plan's relation to how much it can scale up in lower gravity is directly proportional to height. So if you assume gorilla like adaptations, but 300 times as tall, then you need 300 times less gravity which is about 0.3% of Earth's gravity. Unfortunately, this indicates something in the gravity range of an asteroid roughly 100km across rather than anything massive enough to be even remotely planet like. Such a celestial body can not hold an atmosphere meaning your giant gorillas must be anaerobic (so you should probably ditch the heart shaped noses all together). Being anaerobic also solves some of the major issues with the oxygen density required for such a large respiratory system.

However, an asterial body this size does not have enough landmass to feed a population of them. A single family of gorillas on Earth needs about 4-30 km² of wilderness or 0.04-0.3 km² of dedicated farmland to survive. If we assume similar scale megaflora, then that means a single family of your aliens needs about 360,000-2,700,000km² of wilderness or 3600-27,000km² of dedicated farmland, but a planet with low enough of gravity for these guys to live would need to have a surface area of about 32,000km² or less. This means that even with advanced agriculture, a planetoid small enough for them to live on would could not support more than about 40-50 of them, and they never would have evolved to be able to get that far.

So, your best bet for these guys is not to stick them on a single planet, but for them to live in a part of space where there are billions of these tiny planetoids that they can jump between. This way, they never experience crippling gravity, but they have access to tons of surface area that they can cultivate thier space veggies on.

It is possible that these creatures started off normal gorilla size when thier moon fell past the Roche limit of the gas giant they were orbiting, but the breakup was slow enough that they, and the plants on thier world had time to evolve. They've all gone super-sized route because this helps the giant animals leap between large rocks that are many km apart, and the large plants that feed them have been selectively bred by the gorillas because the gorillas only transplant flora that are large enough to make for good eating.

  • $\begingroup$ Thank yall so so so much!! that sounds like such a nice and cute idea and i love it 😭🦍💚 (edited the comment to add yalls preferred pronoun sorry!!!) $\endgroup$
    – nunchucks
    Sep 21 at 16:54
  • $\begingroup$ @nunchucks It's cool, I only care about the yall thing in the second person plural. "You" when used in the second person singular is perfectly fine. $\endgroup$
    – Nosajimiki
    Sep 21 at 17:01
  • $\begingroup$ Oh okie!! ill keep that in mind ^^ $\endgroup$
    – nunchucks
    Sep 21 at 17:03
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    $\begingroup$ @nunchucks also, on WB.SE we generally ask that you not select an answer within 24hr of asking a question because we tend to go on the principle of finding the best answer instead of THE answer. That way if someone else has a better idea than mine, they are not discouraged from answering. $\endgroup$
    – Nosajimiki
    Sep 21 at 17:08
  • $\begingroup$ ty! i appreciate all the tips and patience, I'll make sure to change it !! $\endgroup$
    – nunchucks
    Sep 21 at 17:12

You're in dire straits indeed. For starters, such a size may only be explained either by very reduced gravity or through buoyancy.

In the first case, you need to place your space gorillas in a Smoke Ring. I can think of no other environment that would allow them to survive (the necessary low gravity would not allow an atmosphere).

In the other, they would need to live in an ocean on a light planet. Not gorillas, but whales.

The real problem in both cases is their brain. A 300 m leviathan has a neural delay of three seconds using human-like nerve fibers, plus the delay required by peripheral "repeater" brains (one every 15-20 m). Anything above 0.01 g, and they wouldn't be able to break a fall, or avoid a falling weight (something like that is described in Hal Clement's super-heavy planet of Mesklin, whose inhabitants have a phobia of having anything over their head or letting go of weights, since everything falls too fast for them to see).

Perhaps you can solve several of those problems in one fell swoop by having them live in a cold methane or ammonia sea on a cold world. It might be possible to play with fluid viscosity, and they might have such a sensorium, that this would be to them like air is for human beings. Their lives would be then extremely slow compared to a human's, but to them their world would appear like a normal-gravity, normal-speed jungle (exchanging time speed for gravity and living "normally" under a temporal slowdown is calculated and explained in Charles Sheffield's Between the Strokes of Night).

  • $\begingroup$ Thank you!! this does sound very fun and interesting to look into!:3 $\endgroup$
    – nunchucks
    Sep 22 at 3:25

Low Gravity and High Oxygen are musts for such large fauna. However, being that large would require you to just give a fantasy explanation, but you can still do low gravity and high oxygen to help it along.

This is due to the fact that low gravity reduces the effects of the inverse cube law, due to the fact that it reduces weight so it takes longer to be a problem, and high oxygen also allows them to better oxygenate a larger body.

But, again, this wouldn't be able to explain 0.6km tall creatures without some fantasty explanation or handwavium. A scientific answer for beings of that size simply doesn't exist. Unless you have them live underwater, as underwater creatures can grow far larger than land-based ones. That I feel would be able to be a reasonable expanation for their ability to grow so large. This should be helped via lower gravity as I said before. Both really work to reduce the negative effects of large size.

Other issues do arise, such as the propogation of electricity through the nervous system. Nerve signals move at around 120 m/s, so signals would take 5 seconds to reach the end of their body, which would greatly slow their ability to move and respond to stimuli.


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