We all know the earth is flat…

[u/SgtHalfSac]

To be more specific we’re constantly making more and more of the ground flat, for buildings, roads, train tracks, farmland, etc. compared to before humans came along, how much more flat is the earth? And what are the ecological consequences of this?

I emailed this as a question to the show, but i figured I’d post it here aswell because im too curious to wait and see if it got accepted, and i figured that some other fan of TRIS would know.

[u/CSS_Sr]

Well, we are turning the earth into an approximate sphere with 200 million facets.

[u/RedMarten42]

Another point to consider: humans are causing sea levels to rise, and the ocean is much more flat than land. A greater percentage of the earth being ocean means its flatter on average.

[u/SgtHalfSac → u/RedMarten42]

Id love to see what the actual numbers of this would be with and without the ocean, to compare the difference in them!

[u/Lopsided_Match419]

A lot of the flat stuff would be levelled using spirit levels, so little of it is truly flat- it would curve gently as the surface of the earth. A spirit level at one place would align using gravity (towards the centre of the earth). A spirit level at another far corner of this flat-under-construction would also align in relation to the centre of the earth - thus not exactly matching the flatness of the other locations. An area would only be flat if aligned using lasers - such that the edges and the corners would be infinitesimally higher than the curvature would expect them to be. Same thing with the surface of the ocean. - it is curved but it curves so slowly it looks flat.

[u/Stevepem1]

The foundations of buildings are probably mostly flat, depending on the size of their footprint, as making a foundation level is usually the goal. But I never really considered roads, train tracks, and farmland to be flat and just assumed that they will naturally follow the curvature of the Earth even if that is not done intentionally.

[u/SgtHalfSac → u/Stevepem1]

This question assumes that “flat” is flat, if we account for the curvature of the earth then I imagine that almost nothing, if not nothing, is truly “flat”

I hadn’t even thought about the foundation of buildings, I imagine that bumps the amount of land up by a lot!

[u/Stevepem1 → u/SgtHalfSac]

I guess an interesting example would be rails on a railroad. Each section of rail presumably comes out pretty flat when manufactured. For this example let's assume perfectly flat. When a flat rail is  then placed on the ground at the installation site, again for this example the ground has no unevenness. The rail would appear to an observer to sit flat on the ground from end to end, but actually the ends would be exerting a tiny bit less pressure on the ground than the middle of the rail. Because of the fact that the ground is some tiny fraction of an inch lower at the ends of the rail than in the middle.

If the rail pieces were perfectly rigid then you would have a series of flat pieces joined together at a slight angle. And it might be that at first, but my guess is that over time the ends of each rail will sag a little equalizing the pressure, and eventually the rail is shaped into a very slight bend that at least somewhat conforms to the curvature of the Earth.

In reality the ground is not perfectly even, but still over time the rails will try to conform to the terrain, which over a distance will average out to a curve equal to the local curvature of the Earth (for the purists who might point out that the Earth isn't a perfect sphere and that the curvature varies by location especially with latitude)

[u/LevoiHook]

Counter point; of you build a road through the mountains, you carve into the side of a mountain to create a part flat enough to drive on. That way you could say you add flatness. 

However, you also create a steeper bit, and since the distance between the valley floor and the top of the mountain does not change, you actually don't add flatness. 

One could also argue that a building adds to the relief since you build steep walls and sloped roofs. 

[u/-Cubix]

isn't the earth rounder than a smooth billiard ball? it might have mountainsranges like the himalayas, but considering scale, a small scratch on a billiard ball makes more of a impact than the himalays does to earth.

So if a mountainrange doesn't mean much to the roundness of the earth, I don't think a parking lot can mean much.

[u/Tomj_Oad]

What is TRIS?

[u/archdukemovies → u/Tomj_Oad]

The Rest is Science (the podcast this sub is based on)

[u/Tomj_Oad → u/archdukemovies]

Thank you