Advanced aliens didn't invent/discover this one basic thing.

[u/HotUKTakes]

1. The Santi, from The Three Body Problem, are masters of dimensional engineering. They can build an AI computer the size of a planet, and fold it into the size of a photon.

But they never invented the concept of lying.

1. The Asgard, from Stargate, are an advanced civilization with FTL travel capable of spanning different galaxies. But they need the help of humans to fight their enemies the replicators, a mechanical lifeform comprised of replicating lego blocks, because human guns can blow the blocks apart, while Asgard energy weapons are just absorbed.

The Asgard say the idea to use chemical reactions to launch a blunt object at high velocity never occured to them.

1. Despite having the ability to build a simulated beach, complete with simulated earth atmosphere, The Eridians didn't discover relativity and radiation.

2. The aliens from War of the worlds just lick everything, clearly having no concepts of germs. Which is what kills them in the end.

3. Despite having FTL travel, the Havesters from Independence day, never invented network security, as they are hacked by a human macbook.

[u/Rhasimir]

As a technological civilisation they had the concept of a large source of heat in the sky (their sun) from what I remember, but indeed, night sky distant stars are a very new concept which they only discovered a few decades ago when they figured out their sun was dimming (heat input for the planet was lowering). So they had to had-hoc engineer a space program ASAP, they did not have, like we did, decades or more to ponder why can't we measure a different speed of light when we measure it in different directions (since the Earth moves quite fast around the Sun, the Sun moves even faster in the galaxy), why is Mercury's orbit a bit off, etc. which eventually lead us to Relativity.

[u/quokkafarts → u/Rhasimir]

IIRC Erid is the closest planet to their star, so nothing between them and their sun to observe or have any impact. That combined with no sight meant they just didn't think about space. Like, at all. I think it's mentioned they discovered other planets exist due to finally entering space but give so few shits about them that they don't even give them names.

[u/scotty_dont → u/Rhasimir]

On earth radioactivity was discovered because Uranium crystals exposed a sealed package of camera film in a drawer.

No eyes, no cameras, no camera film.