Does this continue to work at scale? Making everything proportional and such… I would guess they had to significantly increase the jet propulsion to compensate.
Nothing in the world really works at infinite scale because the size of atoms doesn’t change. In order for something to scale infinitely it also needs the environment in which it’s found to scale along with it.
This comment doesn’t actually answer OP’s aeronautics engineering question at scales of human life and plane manufacturing.
Who’s talking about scales of human life? He wanted to know if one could just keep scaling planes and what that would require, and since no else had said anything I gave what answer I could which did contain some helpful information on that subject.
No, he didn’t. Nobody is talking about scaling airplanes to atomic or galactic scales. There’s an actual answer to OP’s question, which an aeronautical engineer could factually answer. You gave a worthless, ‘I am very smart’ non-answer and now double down as if OP was asking about some platonic ideal rather than a genuine engineering question.
Damn, somebody’s having a shit day, huh? You know this kind of negativity isn’t good for you, right?

Look at the size difference between the engines.

The A380’s are enormous.

They’re only about 10-15% more powerful. The 777 has far larger and more powerful engines, but only two of them.
Yeah. Those are huge on the 777.
Since no one actually answered your question: basically yes, you can just scale airplanes linearely up and down. Obviously everything has to scale, like propultion and hydrolics power, but you can esentially make a model aircraft the exact same shape as any large aircraft and it will fly. Conversly, you can test a small model in a wind tunnel and then scale it up as much as you want and it behaves mostly the same way.

I would assume at some point you would have to worry about structural materials being able to hold up to weight being thrown around. It is remarkable how much wings can bend, but I figure at some point joints would need some kind of alternative.

The planes pictured are designed to have ~25ft (8 meters) of bend in the wings.

en.wikipedia.org/wiki/Reynolds_number

Not technically true, but I think when you are scaling up from an A380, it becomes much less relevant.

Reynolds number - Wikipedia