[defrost]

Archivers work fine for myself: https://archive.md/qUlES

There's also a direct PDF link https://iopscience.iop.org/article/10.1088/2752-5295/ade17d/... that also prompts for captcha (unless you arrive there via the web version)

Looping redirects on archive.XX urls often traces back to the use of Cloudflare DNS resolver .. the archive folk have some beef with Cloudflare over (?) handling privacy (?) and loop redirects on connections that arrive via that path.

It's a new captcha type for myself also. Interesting as it requires spatial reasoning and a bridge of understanding between text request and objects in images - although it falls to the usual farm of human captcha solvers.

[out-of-ideas]

nice, well i am using quad9; archive.org had 503's too (edit: lol i wonder if it did complete for me but somehow something else caused a loop - i never went to the search prompt afterward)