"Experimental evidence that a photon can spend a negative amount of time in an atom cloud" (2024)
https://arxiv.org/abs/2409.03680
Additional indications of retrocausality:
- "Robust continuous time crystal in an electron–nuclear spin system" (2024) https://www.nature.com/articles/s41567-023-02351-6 .. https://news.ycombinator.com/item?id=39291044