Submitted by DukeOfZork t3_118firl in Futurology

Apologies if this is not the appropriate subreddit, I'm wondering how long a pyramid might last on Earth's moon. Just a bit of a thought experiment about how humans might leave an indelible mark on the universe that could someday be observed by other intelligences.

Perhaps as a starting point for discussion, would anyone care to fact-check this response I got from ChatGPT? Lately I've been curious about how accurately the tool might be able to provide insights about distant future scenarios based on our current understanding of physics.


Q: If you built a pyramid of Giza on the moon, how weathered would it look after 1 million years?

GPT: Assuming the pyramid on the moon is constructed similarly to the ones on Earth with the same materials and dimensions, it would likely remain very well preserved for an incredibly long time, given the lack of weathering and erosion on the moon's surface.

Unlike Earth, the moon has no atmosphere, no wind, no water, and no living organisms to cause any weathering or erosion. Therefore, any structure on the moon would not be subjected to the same types of wear and tear that affect structures on Earth.

However, the moon is exposed to a different type of environmental factor: the constant bombardment of micrometeorites and other space debris. Over a very long period, this could cause some wear and tear on the surface of the pyramid, resulting in small impacts and crate

Nonetheless, after a million years, the pyramid would likely still be very recognizable, with most of its structural integrity intact. Any wear and tear would likely be limited to the surface, and the general shape of the pyramid would remain relatively unchanged.


Q: What about after 10 million years?

GPT: After 10 million years, the pyramid on the moon would likely still be recognizable as a pyramid, but it would likely have undergone more significant changes compared to after just 1 million years.

Over this extended period, the constant bombardment of micrometeorites and space debris would have caused more significant erosion on the surface of the pyramid. There would be more craters and pockmarks, and the edges and corners of the pyramid would likely be more rounded and smoother.

Additionally, the constant exposure to extreme temperature changes on the moon could cause some expansion and contraction of the materials that make up the pyramid. This could result in some cracks and fractures forming, especially if the materials are not very resistant to thermal stress.

Despite these changes, however, the overall structure of the pyramid would likely still be recognizable as a pyramid, with its general shape and proportions remaining intact. The lack of significant weathering or erosion on the moon's surface means that any changes would likely be limited to the surface of the structure, and the pyramid would likely remain standing for many millions of years to come.


Q: How long would it remain recognizable as a pyramid constructed by intelligent life?

GPT: Determining how long the pyramid on the moon would remain recognizable as a structure constructed by intelligent life depends on a variety of factors, such as the materials used to construct the pyramid, the rate of erosion caused by micrometeorites and space debris, and the effects of extreme temperature changes on the moon's surface over long periods.

Assuming the pyramid is made of durable materials that are resistant to erosion and thermal stress, it could potentially remain recognizable as a structure constructed by intelligent life for millions or even billions of years.

However, over an extended period, other factors could come into play that might obscure the pyramid's origins. For example, the constant bombardment of micrometeorites and space debris could cause a buildup of regolith (loose material) around the pyramid, burying it under a layer of moon dust. This could make the pyramid less visible and less recognizable over time.

Another factor is the possibility of future geological activity on the moon. While the moon is relatively geologically inactive today, there is evidence of past volcanic activity on the lunar surface. If such activity were to occur again in the future, it could potentially bury the pyramid under layers of volcanic ash, making it even less recognizable as a structure constructed by intelligent life.

Overall, it's challenging to predict exactly how long the pyramid on the moon would remain recognizable as a structure constructed by intelligent life, as it depends on a wide range of factors that are difficult to predict with certainty.



You must log in or register to comment.

SapperBomb t1_j9h1oqh wrote

Say micro meteorites and space debris OND MORE TIME!


KamikazeArchon t1_j9h67eu wrote

According to ballpark figures from this article, any given square kilometer of Moon-surface is hit by a small meteor about once every thousand years. Each of those small meteors delivers energy comparable to a ballpark of 3 kg of dynamite.

Over a million years, that comes out to a given square kilometer getting hit with a thousand impacts of 3kg of dynamite each.

The Great Pyramid is about 250m x 250m, so it's about 1/16 of a square kilometer, so let's say it gets about 50 impacts in a million years.

Here is a video of what happens to a fairly large concrete cube when you detonate "just" 2kg of dynamite on top of it (not inside or under, which would be more damaging; this is a decent simulation of how a meteor impact would work). It does not go well for the cube.

However, the Great Pyramid is much larger than said cube. It seems clear that any single one of those strikes would do significant visible damage but would not destroy the structure. 50 strikes shouldn't be enough to do that either - not if they're randomly distributed (as opposed to what we would do in, say, a controlled demolition). 500 (10 million years) seems like it would certainly be enough, however.

Caveat: these are ballpark estimates, and depend in large part on the estimate of meteor impacts and the effect of an impact on the material. I used concrete as an example, but solid stone would be more resilient, and something like a hardened, reinforced bunker with modern building materials would be even more resilient. This also doesn't take into account larger meteors, simply because we don't have a reliable estimate of their rate-per-year.


SnooPuppers1978 t1_j9hfd18 wrote

So overall it sounds like ChatGPT is accurate?


Peace-Bone t1_j9hkrph wrote

Only one way to find out. Get in the spaceship, we're making a pyramid.


DukeOfZork OP t1_j9mcuav wrote

Thanks! I hadn’t seen that resource. It does seem GPT is somewhere in ballpark, and it includes plenty of caveats.


NexexUmbraRs t1_j9gysph wrote

Yeah I don't believe that it would still be recognizable after 1 million years... That's a lot of time and it only takes 1 good meteorite to hit it or nearby in order to cause a crater. Idk about you but a hole doesn't look anything like a pyramid.


DukeOfZork OP t1_j9mdmxh wrote

True, another user broke down the distribution of meteor strikes over time, but that’s all averages. A big one could wipe it out in a single go, but is more unlikely.


beders t1_j9iikhl wrote

Isn’t it immediately obvious to you that chatGPT just replaced whatever was in the original text fragments with “pyramid” ? How can you ever trust such answers ?