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.

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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.

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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.

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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.