- A Hackaday article and an Optica paper were shared describing a new “fluidic shaping” method for molding free-form optical components; participants speculated that adding electric-field control of wetting angles could give even more degrees of freedom.  
- DIY lens-making was discussed, including a YouTube tutorial on casting epoxy lenses and the suggestion to use a two-part mold (thin silicone inner surface plus rigid plaster backer) to cut cost and improve surface accuracy.  
- CR-39 (allyl diglycol carbonate) was highlighted as the preferred plastic for eyeglass lenses because of its high Abbe number and low chromatic aberration, especially for prescriptions above ~8 diopters.  
- Novel reflective-eyewear concepts were floated: using convex mirrors in a Cassegrain-like layout to shrink high-prescription optics, and a three-mirror periscope arrangement to move the corrective element away from the eye.  
- Nitinol’s high cost and processing difficulty were debated; a Cycling Weekly piece on a proposed bicycle derailleur that uses Nitinol as an electromechanical actuator was cited as an example of its potential.  
- A Medium post titled “Why is Everyone so Consistently Wrong about Launch-Assist Systems?” was linked, prompting discussion of tethers versus orbital rings and skepticism about momentum-exchange tether schemes.  
- Quick calculations showed that a 100 m tether tip moving at 30 km/s would impose ~900 000 g, illustrating the extreme material demands of short, high-velocity momentum-exchange tethers.  
- Participants referenced the “two-tier” or multi-stage spinning-tether concept and the extensive tether-bibliography archive at tethers.com as background reading.