"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
"3D waves flowing over Sierpinski carpets" gives intuition about (convolutional) wave products or outcomes but doesn't show any retrocausality from here: https://youtube.com/watch?v=8yddkbwrqss&