So no, they are not foldable today - the headline submitted to HN is total clickbait.

I can't say for certain, but I believe Boeing may have explored this concept at some point. The idea would be to equip aircraft with mechanically extendable wingtips that could expand outward by several meters during flight and retract while on the ground.

The primary challenge is that most airport gates cannot accommodate aircraft with a significantly larger wingspan. Retractable wingtips would allow the aircraft to benefit from the improved aerodynamic efficiency and fuel savings of a longer wing in flight, while still fitting within existing gate infrastructure during boarding, deplaning, and parking.

That's a meaningful improvement but not that big. Perhaps the limits to this kind of technology are ~50% fuel gain? https://www.technologyreview.com/2013/01/24/180345/hybrid-wi...

We've got AI, but I'm still waiting on exponential technological gains. So far I've mostly gotten exponential enshittification of my google experience. Is AI going to unlock the detonation engine and bring down the cost of my plane ticket? https://www.technologyreview.com/2012/11/23/181486/exploding...

... doesn't look like there's any folding being tested here, just the resulting wing shape to see what the benefits might. Full scale foldable wings would be years off.