- Seacrete (electrodeposited calcium-carbonate “cement” grown from seawater) was re-evaluated: German industrial cement now averages only 0.4 GJ per tonne, making Hilbertz’s original 80 GJ/tonne estimate ~200× too high and undercutting seacrete’s cost advantage.  
- Participants explored work-arounds: substituting low-grade thermal energy for electricity, exploiting the same electrochemical gradients that create boiler scale, and situating growth reactors in existing solar-thermal salt ponds to leverage salinity-enhanced conductivity.  
- Ion-exchange membranes were proposed as a way to swap sodium for calcium in seawater, tailoring brine chemistry to accelerate seacrete formation while lowering electrical demand.  
- A Conversation article on COVID-19 testing and open-source insulin was shared as evidence of biohackers rapidly deploying decentralized science tools during the pandemic.  
- A ScienceDirect paper claimed laser-induced annihilation of “ultradense hydrogen” (Rydberg Matter) could yield 100× the usable energy of fusion and enable relativistic interstellar propulsion within a decade; reactors were asserted to already operate in Sweden, Norway, and Iceland.  
- Discussion cast doubt on the claim: ultradense hydrogen remains unconfirmed, the mechanism lacks independent replication, and the paper conspicuously omits the word “antimatter,” prompting skepticism and “cold-fusion” comparisons.  
- Reference was provided to a 2019 Physica Scripta review by Holmlid & Zeiner-Gundersen as the theoretical basis for the ultradense hydrogen concept.