My dad and I have been talking at the way home about really high people and how they must feel (basketball, volleyball!!) and how it would be to be like them.

But then the conversation leaded into a completely different direction: ....

We've all seen those movies with big giants in it which move extremly slow.

And we are shure that those giants wouldn't move that slow.

But imagine a 1km (0.62 miles) high giant on our world living with us normal sized people. This would be a completely different dimension. Lets assume he speaks English and has the exact same look as we have but much bigger and higher (muscles, bones, etc. adapted). I mean, is it even possible to have such a giant!? Is it possible for him to exist? Would there be any problems?

And how much would his movement-speed differ from ours? Would he speak any slower than we do? Or would he just speak and go as normal as we do (but with other dimensions...)?

And if its really possible for such a giant to exist: What are the benefits he has over us normal sized people? Is there a way we (so humanity) can somehow benefit from it? Is there a way we can cooperate?

Some comparisons between movement of this giant and normal sized people would be really great. (giant vs ns people - throwing a ball, doing a salto, jumping, running, ...)

I mean, I know this question here, but 1km (0.6 miles) is clearly another dimension.

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    $\begingroup$ Without some really nifty engineering of the skeleton and muscles the 10km giant is going to collapse under its own weight. So you have to clarify: Do you want a giant as large as our fysiologies allow, or an engineered 10km super-human? As for how "slow" it would go. Its going to move at similar speeds as us , but when moving a leg we only need to move it half a meter and the giant a kilometer or two besides that the moment of inertia is going to be much higher. So it will look like its moving slower, but with each stride he can cover more distance. $\endgroup$ – Demigan Apr 1 '18 at 18:43
  • $\begingroup$ @Demigan an engineered super-human! I edited the question, so it would be "a little bit more realistic"! $\endgroup$ – watchme Apr 1 '18 at 18:45
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    $\begingroup$ Also, note that movies show giants moving slowly because we humans have come to visually interpret the motion of very fast or very large things in that manner. I blame The Six-Million Dollar Man, which intentionally presented his super speed in slow-motion, probably because it was cheaper to produce (besides, what's the value of watching him save the Damsel-in-Distress in a tenth of a second?). $\endgroup$ – JBH Apr 1 '18 at 22:23

Sorry, but it would differ by being dead :(

Take a look at my answer here: https://worldbuilding.stackexchange.com/a/322/49

We would struggle to build a 1km high building. The current world record is 828 meters high, which is still short a km. That's a non-moving structure made of iron and steel not a living organism of flesh and blood. There is no currently conceivable biology that would allow something as large as you are describing to survive.

The tallest trees (again not mobile, but at least it's biological) is 115 meters.

The good news is that the air is still breathable at that height so at least he can breathe. The problem though would be the monumental amount of air needed, the giants would need some massive adjustments to their lungs.

Even if you manage to solve the structural problems the calorie requirements would be horrific to sustain a body of that size. It just doesn't seem feasible.

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  • $\begingroup$ I meant a giant where all body parts and functions are adjusted to his height, so he can walk "normally" $\endgroup$ – watchme Apr 2 '18 at 11:09
  • $\begingroup$ @watchme I know what you mean. It's impossible. You can't make the adjustment. Physics says no. Read what I wrote and the linked answer for why. $\endgroup$ – Tim B Apr 2 '18 at 11:11

It seems impossible to make a 1 km high living creature with the actual laws of physics.

You just can't scale up a human and turn him into a giant without drastically modifying his anatomy in order to keep him alive.

The tallest people alive (more than 8 ft / 2,4 m) have many ealth issues and don't live long. Their bones break easily because their body is too eavy for their skeleton.

So, if you want to create a 10 meter high giant, you must give him massive legs and stronger bones (like elephant's legs). But he would probably be unable to walk on two legs like humans, and would more likely use his arms and walk like a giant gorilla. So he might not be able to throw a ball, and would never do a salto.

His heart would have to be very big to pump blood and send it to the brain. He would have trouble to stand up, and would rather keep his head at a lower level to ease his heart and help the blood flowing to his head. As his body adapts to his new posture, he may loose the ability to speak like humans, and would probably only make deep grunts.

It will be more difficult for him to cool his own body. He would have to find a new way to regulate his body temperature, or he would die of hypertermia.

And yes, he would be slow. Giant animals are always slow. They need more energy to move, and their nervous system is less efficient. The bigger you are, the more time it takes for nerve impulse to travel through your body. That's why elephants walk very cautiously : if they step on something sharp, it will take more time for them to notice it.

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  • $\begingroup$ I meant a giant where all body parts and functions are perfectly adjusted to his height, so he can walk and live "normally" $\endgroup$ – watchme Apr 2 '18 at 11:09
  • $\begingroup$ Note that the Titanosaur was 37meters long - not tall. Tall would be significantly harder. $\endgroup$ – Tim B Apr 2 '18 at 11:12
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    $\begingroup$ @watchme What I'm trying to explain is that 1km tall human can not exist in our physical world. It's impossible. The giant you described could never live on Earth. He belongs to fantasy, not to science. $\endgroup$ – Ghajini Apr 2 '18 at 11:51
  • $\begingroup$ Sauroposeidons height was 7 m./22 ft. at shoulder. The rest was all neck. Not quite the same thing. $\endgroup$ – Len Apr 2 '18 at 14:13

If the giants have the same proportions as ordinary people, each giant would weigh more than 100,000,000 times more than an ordinary person.

With a world population measured in billions, there are serious concerns about how we can sustainably grow enough food to feed the whole population.

These giants would be very rare, because each giant would have a food budget comparable to that of a major country.

Ignoring the physiology changes required for the giant to support its own weight, breathe enough, dump enough heat to stay at optimum body temperature, and maintain reasonable blood pressures throughout its body:

  • The giant's speed in any given form of motion would tend to scale with the square root of its height. This is a well-known rule in ship design (the relationship between hull speed and length), but a similar rule also applies to land creatures that move using pendulums. The natural frequency of a pendulum decreases with the square root of the pendulum's length, but the pendulum traverses a distance proportional to its length with each stride. So the giant's walking speed might be about 50 miles per hour.

  • The giant might be able to play a few human-scaled games. If it balanced on the ball of one foot, it might be able to stay in-bounds on a football field or soccer field. Because baseball and tennis allow players to stand outside of the playing area, it could lie down and play paddy-paws with the normal-sized players.

  • To avoid stomping on people (and their things), the giant would probably wade in seas, lakes, and wide rivers. Its feet would be something like 500 feet long and 150 feet wide, so ordinary highways would be too narrow for it. Whereas a 1,000 foot deep sea would only be about thigh-high.

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  • $\begingroup$ thanks yes, I thought so! I have changed the question so it would be "a little bit realistic"! $\endgroup$ – watchme Apr 1 '18 at 18:42
  • $\begingroup$ 200,000,000, actually. $\endgroup$ – Praearcturus 6 hours ago

A 1km high giant wouldn't be viable at all because his/her bones would crack under their own weight and the more under the weight of the flesh attached to them!

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  • $\begingroup$ Some mention of the Square–cube law and Allometry would help. $\endgroup$ – RonJohn Apr 2 '18 at 0:52
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