The Mirrorworld of Microsoft Flight Simulator

September 10, 2020

In Microsoft Flight Simulator (MFS), you can fly literally anywhere in the world. Using data from Bing Maps, the development team created an algorithm that could translate map data into a game world at scale. In addition to the autogenerated globe, the team went in and handcrafted several airports and world locations for added realism. The game's ambition is even greater than its 100 GB download size.

While chatting about the sim at work, a colleague mentioned that MFS was likely the closest thing that currently exists to a mirrorworld of the actual Earth.

Mirrorworld, a term first coined by David Gelernter in 1991, was first brought to my attention by Kevin Kelly last year. Kelly argued that the coming augmented reality (AR) revolution will require a digital copy of the Earth to use to develop our new graphical tools. If you want to apply virtual sunglasses over the Statue of Liberty, then you need a digital model of the Statue of Liberty to develop the placements. If you want to see what a sofa will look like in your living room, you need both a digital model of the room and a model of the furniture.

Mirrorworld is a map. A reduction of the “real world’s” dimensionality reproducing its most overt features. As our desire for increasing granularity and generality from AR and virtual reality (VR) products increases, so does our need for more precise models. Taken to the extreme, mirrorworld will eventually become the ultimate map. Mirrorworld will become 1:1.

With its entirely navigable globe, MFS is an iteration of mirrorworld.

Judging by the mysterious obelisks and underwater roadways, MFS may not be its final incarnation. As this Twitter thread illustrates, MFS didn’t exactly nail every aspect of the globe. My neighborhood park proved particularly difficult to handle. The sim elevated the public pool into a stubby, blue-roofed building, but shrunk the pool locker room and field house buildings into mere roofs on the ground. It didn’t even try with the gazebo.

While those defects feel like somewhat honest mistakes, others are far more eyebrow raising. Glaciers at the poles were an afterthought with some isolated sheets rising into the tens of thousands of feet tall ice walls. Cars drive vertically up the sides of buildings. Craters are inverted. With the limitations of consumer graphics cards, it would have been reasonable to assume that mirrorworld would be somewhat cubist, but now we know it may also be surrealist.

However, the bizarreness of the world is countered by the realism of the cockpit. Those spaces are truly mirrorworld quality. Every button and control is faithfully replicated. As a beginning virtual pilot, it's been a bit overwhelming and keeps me flying my trusty analog Cessna over the incredibly more complicated 747. When you sit in the cockpit, there is no heads up display. Instead, if you want to know your altitude, you need to look at the altimeter in the plane. You may have to adjust your field of view to see this. When you have questions or are confused, the game provides few answers. Instead, it's much more useful to look at the actual aircraft manual! When I couldn't find an indicator to tell me the position of my flaps, I needed to Google how to deploy flaps in an actual Cessna. That's realism baby!

My appreciation of the game has gone through stages. At first, I was excited by the world's potential and my ability to fly anywhere. I visited my house, my grandmother's house, my university, and most impactfully my childhood home town. I was literally brought to tears by the realness of its recreation and how it's changed since I've been gone.

Next, I was amused at some of the ludicrous transformations I witnessed. Cars driving on water, bridges seemingly non-existent, European churches flattened to a painted shape on the ground. It was funny until I realized that the algorithm just couldn't handle architecture that didn’t conform to dominant modern archetypes. Historical architecture was uniformly erased. Similar to how developers supplant vernacular architecture with increasingly uniform replacements, New York City skyscrapers and cookie cutter suburban homes are used to model the entire globe.

Flattened Church

Despite this realization, the hollowness I felt soon began to be filled with absurdity. Instead of bemoaning the erasure of any distinctness of place, I began to see its insertion. The giant ice plateaus, mysterious monoliths, and impossible traffic patterns soon became the best part of the game. Instead of admiring the algorithm's reasonable interpretations, I became entirely fixated on its nonsensical failures.

If the best parts of our current mirrorworld are its absurdities, what does that mean for future iterations? If mirrorworld needs to be ruthlessly functional, then the bugs need to go. But what if mirrorworld could be something different? Can mirrorworld entertain? What if mirrorworld needs to capture not just how the world looks, but also how it feels? If mirrorworld needs to accurately describe our world, doesn't that mean it needs to be somewhat surreal?

Ultimately, the answers will depend on the applications, but if you’re looking for the true mirrorworld that’s already here, I’d direct you to


© 2020 Connor Daly