# Key Technical Discussions from #hplusroadmap IRC

• Participants discussed developing a physical simulation program (physim) that processes XML descriptions of free body diagrams to simulate systems over time, potentially valuable for transhumanist hardware development projects.

• The conversation explored advanced constraint systems for CAD software that would go beyond geometric constraints to represent physical quantities, protocols, and interfaces between components using triples (object-operator-value) with weighted constraint priorities.

• There was debate about implementing a constraint solver capable of handling both discrete variables (like chemical compounds or bolt sizes) and continuous variables, with disagreement about computational feasibility and implementation approaches.

• Steve Mann's eyetap wearable computer designs were referenced, particularly his 2mm frame design documented in a paper at wearcam.org/carpe/carpe.pdf, as relevant precedent for wearable technology development.

• Technical limitations of a spiral filter design for fluid processing were discussed, with kanzure noting scaling problems (only effective at microliters/second with laminar flow) while others wanted to experiment with larger implementations based on a PARC paper describing 300 micrometer channels.

• Participants identified practical challenges in open hardware development, including the cost premium of retail materials (approximately twice the price at stores like Lowes compared to industrial suppliers like Enco) and issues with academic software sharing due to provisional patents.