In a future with great scientific advancements in architecture, engineering and science (where all three work together to create solutions to many problems that city planners, architects and civil engineers face today) is it possible that a society could live in a large hole, mineshaft or cave? More specifically to the world I am currently building, would an enormous skylight that essentially covers the 'mouth' of the hole provide ample light and life to the people living in the city bellow?

I am after a semi-rational scientific explanation as to why humans have looked underground as a solution to earth's surface becoming unliveable.

With the light of a skylight, some way to produce food/water would this make logical sense for a society that has long abandoned the dream of finding a habitable planet in the cosmos to move to?

  • $\begingroup$ Hi, I just proposed an edit to your question because you appeared to be asking two very different questions in the topic line and the body of your question. I hope I chose the one you're actually driving at! $\endgroup$ – SudoSedWinifred Sep 4 '16 at 15:17
  • $\begingroup$ I would suggest so that the earth's surface can be used for something. Agriculture, solar energy, or to be covered with big lasers and stuff to be used as a death Star. $\endgroup$ – Salmoncrusher Sep 4 '16 at 16:24
  • $\begingroup$ You are not asking "What would make the surface unlivable?" but are asking "Given an unlivable surface, why would people go underground as opposed to other possible options?" $\endgroup$ – Xplodotron Sep 4 '16 at 18:24
  • $\begingroup$ Sounds like the book, and later movie, 'The City of Ember' by Jeanne DuPrau. $\endgroup$ – EveryBitHelps Sep 4 '16 at 21:17

There are as many potential reasons to avoid the surface of a planet as we have hours to sit around and brainstorm them, so I'll just offer what I view as the most proximally-likely scenario and count on the community to contribute to the diversity of answers.

Autonomous Drone Warfare

When every dot on the horizon that might be a seagull might also be an autonomous drone bringing a payload of missiles to your address, that provides ample motivation to make yourself and indeed your entire community invisible (or at least inaccessible) from the sky. The thing about emerging technologies is it can be difficult to control access to them. The drones on the horizon might belong to your government (which may or may not make you feel safe), another government (which probably wouldn't), or just any damn kid with a 3D printer and a set of schematics they downloaded from some edgy website. Americans in particular like to kill as many people as they can manage every once in a while, whether because the CIA brainwashed them or a girl rejected them. Imagine James Holmes with a dozen armed drones. Yeah, let's just live underground, now.

One other point... You seem very attached to the idea of access to natural light, but so long as there are alternative energy sources available (nuclear and geothermal spring to mind) it's not strictly necessary. Thanks in large part to the efforts of the US Drug Enforcement Agency (or rather, to citizens' efforts to counter that institution), growing plants without natural light isn't even a rich man's game: it can be accomplished surprisingly cheaply, easily, and with a minimum of energy input thanks to the advent of LEDs that produce just about any wavelength of light you'd like (LEDs that produce agriculturally-appropriate wavelengths are very commonly manufactured and benefit from the economy of scale.)


if the atmosphere were to become unbreathable:

Say, if a supervolcano erupted and ash was in the air, or nuclear war made the air radioactive, then living underground with air filters becomes preferable

fallout / global warming

if the surface temperature became either too hot or too cold, we could grow crops underground and theoretically live underground


without access to direct sunlight, you would get a Vitamin D deficiency, which is not healthy, but presumable if you can generate enough UV light to grow crops then this isn't that problematic, but most importantly: for the use of fiction, the science can slide


The ozone layer is almost completely eroded, leaving the surface of the planet exposed to the sun's unfiltered radiation. You can go above ground, but will quickly develop radiation sickness.

A series of large skylights made of quartz or some other kind of translucent mineral could filter the radiation enough to give sunlight for crops, vitamin D, etc., in a subterranean colony.


The surface of the Earth has slowly heated to unlivable temperatures.

A plateau has been predicted in the near future. This will be the new Earth.

There have been investigations on how to continue humanities existence for decades.

It is found that, to move to a new planet or moon would take far too long, would strip humanity of their resources and create an unknown future. Limited lifestyles at best. Humanity voted on it's future and it's choice was clear.

The more favorable option is to move to the much cooler underground. The heat being trapped in the atmosphere creates strong winds encircling the planet. This powerful heat and wind is used as an abundant source of energy. The moisture in the atmosphere along with underground rivers are used as a constant water supply. The abundant energy is enough for humanity to carry on living happy, healthy lives with hope for the future.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.