Simon and Rachel are bickering again, this time about 3D printing. Is it old news, or are recent developments in generative design enough to make it fascinating? Simon thinks it's a toy, no more likely to catch on than Betamax, Rach thinks it's the future of everything. Who is right? We will have to wait and see. Our theme music was written and performed by Laurence Owen. Graphics by Theo Weedon, web design by Ian Bridgeman, support from the Wellcome Trust. The producer is Rachel Wheeley. More information about the series is at www.leveluphuman.com and you can support us at www.patreon.com/leveluphuman