In the book The Quantum Universe, the author suggests that:

If the human race evolved in an underground cave system, never to see the sky, it is possible that they could have imagined a ball of gas and calculated its maximum mass.

This is in reference to the Chandrasekhar Limit.

Anyway, if the human race had evolved inside an underground cave, how would science have evolved? Would our current level of technological development be possible (assuming you could mine for resources)?

For example, would Cave Newton have developed his Law of Gravitation without having observed the motions of the planets?

  • 2
    $\begingroup$ One of those rare questions that actually fits the [science] tag, +1 $\endgroup$
    – Aric
    Aug 18, 2017 at 11:36
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    $\begingroup$ Plato's Allegory of the Cave... We actually are in the situation of cave-dwellers, because we cannot directly perceive the ideal Forms but only their imperfect and distorted shadows which make up what we call the real world. $\endgroup$
    – AlexP
    Aug 18, 2017 at 13:45
  • $\begingroup$ I can't help but think they would have found a way out of the cave long before reaching our technological level. Humanity is quite good at figuring out how to get into/out of places, has been for a long time. $\endgroup$
    – Megha
    Aug 20, 2017 at 2:48

2 Answers 2


Let's have look, at what you can do living underground:

  1. They can determine that the earth rotates. (pendulum)
  2. If they do some measurements they'll find out that the earth is a ball, if their caves are a global system.
  3. They could define Kelvin, find out what is the lowest possible temperature.
  4. They would at some point measure the flow of the temperature within the earth. How much heat is produced in the core and how much heat radiates away at the surface if it has a certain temperature.
  5. By 2.-4. they can calculate the radius of the ball. (Depending on whether a star heats it up they might get it completely wrong)
  6. Measuring earthquakes precisely should determine the radius more precise. It will lead them to the question what the additional heat source is. (That is assuming there is a star close by.)
  7. Making measurements like in point 6 leads to the discovery of tides. (If they aren't already known.) Using 1. they'll calculate, that the sun circles the earth once every year, while the moon does so once every month. They'll probably assume that the moon is bigger and the heat source is something else, like the temperature of space.
  8. Things get harder now. Determine that tides are actually some form of gravitation is for them probably as hard as for us the discovery of relativity theory. That leads quickly to somebody measuring the gravitation constant $G$. With that in mind they can sort out the solar system: The earth is bound to the sun, while the moon is bound to the earth.
  9. At this point the society is generally on a technologically level as today. At latest when using particle accelerators they will find out that fusion exists. They understand that the sun might do fusion. That solves the temperature problem from 6.
  10. With more precise measurements of tides they might discover more planets. The tide from Venus is at it's hight about 0.007% of that of our moon. They might measure that.

So yeah, they might discover that there are other planets. Of course things might go in completely different direction.

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    $\begingroup$ Why no nuclear reactors? $\endgroup$
    – Alexander
    Aug 18, 2017 at 17:10
  • $\begingroup$ Observation of extraterrestrial bodies was not required to work out what was in an atom (although light is pretty crucial, but can be created) and so development of nuclear power is possible. $\endgroup$
    – Beta Decay
    Aug 18, 2017 at 17:38
  • $\begingroup$ Similarly, development of particle accelerators is extremely unlikely to come before nuclear power $\endgroup$
    – Beta Decay
    Aug 18, 2017 at 17:39
  • $\begingroup$ @Beta Decay I didn't consider that. But they might work around that problem when trying to understand radioactive decay. Like "Does uranium decay if you send some neutron into it's core?" $\endgroup$
    – lurch
    Aug 18, 2017 at 17:47
  • $\begingroup$ @Alexander I might be wrong, but I assumed that the idea of nuclear reaction is based on the observation that that's how our sun gets it's energy $\endgroup$
    – lurch
    Aug 18, 2017 at 17:50

You can observe the same laws of physics anywhere in the universe. It doesn't matter where you live, you can and should come to the same conclusions.

But what degree of science would they have? How far would they have developed?

Well, we cannot answer that. Look at us normal above-the-ground humans. My grandfather once told me a story of how his village was visited by a witch once when he was a child, at least his mother believed she was because of her nose. The cows certainly did not like her. He is still alive and lives in what most people would call a developed European country. This is just an example of how perception can change within a single generation. Written human history (let's say = attempts at science) dates back to 4k B.C.. We still tell the time like those people did, based on a system on the number 60. Those people were truly amazing, but the people living on the British isles of about that time took a thousand years to pile a bunch of stones on top of each other. One of the more overrated achievements of the human race if you ask me.

If human perception/ability/technology can drastically change within a generation as well as geographically, you should see that it is just impossible to answer "if x were the case, what would people think/have developed?". Too many variables are at work here. You cannot even make such a statement for us above humans without asking specifically about one point in time and space or even a single individual human.

This might be a bit more general than your question, but I do not think you specifically asking about one thing changes anything. How we view our world scientifically has changed drastically within the last 50 or so years. And then came our super fast computers and changed everything again. Also there are so many branches of science ... We always get back to the fact that one cannot answer that question.

For the sake of a story/world, you can do it any way you want. It might have taken them longer, but technological progress is, as the word itself suggests, no constant in time and it isn't even a constant in space. Maybe they would've been faster, who knows. Maybe there was a nerd cave that developed fast while the cave next door didn't at all. And then there was a plague and the other cave caught up. There are so many variables. Btw, I doubt very much that the law of gravitation which is often associated with Newton had as big of an impact as Coulomb's law for example. What do planets matter if you want to produce microchips? I'm sorry my dear Astronomers, but if I had to build a civilization and given the choice, I would take the electrical engineers instead.

The only thing I want you to consider is of course that you shouldn't flood a cave with toxic industrial waste, but that is a given I think. We shouldn't even have done that above the ground. If you want you can even have them dig tunnels to the surface to "blow of steam" there.

  • $\begingroup$ I wonder if the study of planetary orbits and other astronomic phenomena led to unique advances in math. I know that early European and Arabic astronomers were able to calculate the orbits of planets fairly accurately, and I suspect, but do not know, that without the study of space and astronomy, mathematics would have been set back significantly. $\endgroup$
    – Dent7777
    Aug 18, 2017 at 12:40
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    $\begingroup$ @Dent7777 I also would support the argument that humans would've developed slower on average underground, but for the sake of a story one can easily argue the opposite. Maybe those great minds (let's say there would've been just as many) would've been more useful if they had developed a better understanding of something else. The point is that we do not know for sure and I there cannot be a clear suggestion on how one should build his world or how such a hypothetical question must be answered. $\endgroup$
    – Raditz_35
    Aug 18, 2017 at 12:43
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    $\begingroup$ @Dent7777 This is always a problem with those implicit ceteris paribus questions. I think c b is implied here since the OP did not specify that his humans had changed. I had some arguments already here when people assumed everything else stayed the same and I thought one couldn't assume that. It is even implied here that the same Isaac Newton lived. Since this is scifi/fantasy stuff mostly, I think it is ok to assume humans do not change. But if anything, this would make the level of development even more uncertain and give the (let's say) writer even more freedom. $\endgroup$
    – Raditz_35
    Aug 18, 2017 at 12:58
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    $\begingroup$ @Dent7777 PS: On the topic of that, I've recently netflixed the worst pile of crap I've ever seen, the DS9 episode "Crossover". Maybe you know that one, they did basically the same thing: Changed the world drastically but almost everything stayed the same for no good reason. Much worse than saying humans remained the same psychologically underground. For some reason that show had and still has a lot of fans and must have made some money. Sometimes it is ok not to overthink given your audience and goals or you never get anywhere $\endgroup$
    – Raditz_35
    Aug 18, 2017 at 13:04
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    $\begingroup$ Changing the setting and history without changing the result is a classic trope of science fiction and fantasy. How many old Doctor Who and Star Trek episodes involved worlds that were different from ours, whose citizenry was nearly indistinguishable from human? I personally don't subscribe to the idea of strict convergent evolution, especially across planets where life developed on its own. I guess it would be tough to write an episode about thin films of gelatinous ooze. $\endgroup$
    – Dent7777
    Aug 18, 2017 at 13:55

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