- MIT researchers unveiled a photonic accelerator that encodes both weights and inputs optically, enabling on-the-fly reprogramming and training of neural networks at sub-attojoule energy per MAC—potentially below the Landauer limit—via coherent detection and free-space optics (Phys. Rev. X 9, 021032).  
- Channel participants noted that the Andregg brothers, formerly of Halcyon Molecular, are now reportedly working on optical computing hardware.  
- A full transcript of Ron Rivest’s VDF Day ’19 talk “Comments and Observations about Timelocks and VDFs” was added to the diyhpluswiki, alongside links to the survey paper “A Survey of Two Verifiable Delay Functions” (eprint 2018/712) and an asynchronous VSS protocol paper (arXiv 1902.06095).  
- DIY bio discussion touched on spray-on skin culture and the casual mention of PEI-based genetic modification injections as a “cool kids” trend.  
- A new perovskite-based solar material claimed to be cheaper and more scalable was circulated (JACS 2019 DOI 10.1021/jacs.9b05893).  
- Neuralink’s July 2019 launch event video was shared for those who had not yet seen the presentation.  
- Conversation turned to anti-satellite capabilities, with speculation that the X-37B spaceplane could be designed to capture and de-orbit other satellites, while an Economist briefing on the growing attractiveness and danger of satellite attacks was linked.