# What would be the effects on the enviroment if a Giant walked by in a world with Earth like physics?

I recently came by the many questions of scaling creatures and the square-cube law in real world physics right here, and it piqued my interest a bit to make this question. Think of it as an exercise but I truly would like to know :)

Here are the details:

The world behaves by real world physics, it just happens that by some reason magic exists, and there's a race of Giants towering in around six thousand meters.

These Giants' bodies function exactly like our normal bodies, under our own rules of physics and biology following them perfectly. It just happens that thanks to Magic, these bodies are actually possible, but besides this, to reiterate, their bodies are completely natural and follow the rules of physics and biology without fail.

Now, under these circumstances, one of these Giants decided to pay us a visit, and in doing so, he walks by a forest, comes over a mountain, and walks through a city.

What would be the natural effects his mere presence and walking would have on nature/environment in these three cases?

Thought this would be a fun question to ask, an interesting one too, and a good one for my first question here. Have fun :)

• I'm unclear; is the giant six meters tall or six thousand meters tall? I know some countries use a decimal point instead of a comma. From some quick and dirty math, say the average American male is 2m tall and weighs 85kg. If the giant is 6m and scaled proportionally then it would weigh in around 255kg. If it's 6000m then 255,000kg or 255 metric tons. – achinaghost52 Jan 17 '18 at 3:16
• @achinaghost52 Your math is off. 85 kg scaled up by a factor of 3 would be 27 * 85 (2295 kg), not 3*85. This is because mass is based on the product of height, width, and depth. I.e. you need to cube your scaling factor. For the 6km giant, mass would be 2295 megatons. And to get back to the question, a 6km giant would not be able to walk through a city. A 6km giant has km long feet which are around 200 m wide. The giant would have to step on buildings to go through a normal city. – Brythan Jan 17 '18 at 3:27
• Oh, I'm sorry. I didn't take into account the meaning of decimal points between countries regarding numbers. It is Six Thousand meters tall. Thanks for pointing this out. Edit: @Brythan I see, but the question still applies since I'm asking for the effects in nature/enviroment :) not if the Giant can do it without destroying anything or not. – Emmanuel Gonzalez Caseira Jan 17 '18 at 3:29
• @Brythan, whoops, you're right. Forgot about the cubing – achinaghost52 Jan 17 '18 at 3:51

OK, first thing's first, let's get something out of the way...

their bodies are completely natural and follow the rules of physics and biology without fail. This can't be true or the giants would instantly collapse into a shivering pile of decaying biomass that would take a century to stop stinking. If we ignore that, the giants would be forced to sleep all day as the oxygen at 6km and higher is too thin to support a creature even a fraction of this size. And if we ignored that, one giant's food intake would bankrupt a nation in a week.

But, let's just ignore your sentence. In the spirit of your question, let's assume the giants exist and we found one strolling across the country.

• A 6km-tall biped would weigh as much as a moderate-sized mountain. He'll lift his leg about 20% of his height off the ground, or 1.2Km. The force of impact would create a crater hundreds of meters deep and somewhat wider than his foot, which is, what, 0.5km x 0.2km? New lakes would form in his every footstep.

• You don't say what time period we're working with, but if it's modern day, then airplanes are swerving to avoid him and occasionally hitting him because his speed is fast enough and his ability to turn abrupt enough that even with radar tracking his skeletal structure, they'd have trouble.

• He'd disrupt all but the largest weather patterns. He'd create wind with is passing. Heaven help us if he decides to run or jump.

• At 6km in altitude, the humans wouldn't even look like ants. He might notice the patchwork ground (agriculture), but he'd likely only think it's natural. A massive tree would be about the same size as a hair on his finger. Consequently, death and destruction would follow in his wake.

But all of this is fairly obvious... Are you sure you meant 6km tall?

• And let's hope he doesn't fart or burp... – L.Dutch - Reinstate Monica Jan 17 '18 at 6:26
• @L.Dutch.... oh.... his flatulence could cause global warming.... – JBH Jan 17 '18 at 14:06
• @JBH I did meant 6km tall. As I said, this question was more on the lines of a fun thought exercise than anything, that's why I stated that by "magic" the Giant is possible, but otherwise it functions like a healthy body and follow the same laws of physics. I liked the examples you provided :) I was expecting these kinds of scenarios and those that I didn't consider, like the airplanes one, when asking this question, and I wondered what I would be missing thinking about this. I also wondered about how much heat it would generate and that kind of thoughts, but either way thanks for you answer. – Emmanuel Gonzalez Caseira Jan 17 '18 at 15:26
• Provided that most of Earth look barren of anything edible, do they practice cannibalism in order to satisfy their hunger? – NofP Jan 17 '18 at 17:32
• @NofP, the OP explained that the giant's existence (and therefore subsistence) is magically derived. He's only interested in the physical effects of the giants moving around. – JBH Jan 17 '18 at 18:24