Tech expert Steve Caplin is bemused by the UK's go-ahead for self-driving cars only on motorways and no faster than 37 mph. He looks at Amazon's trials of contactless palm scanning, at their smart doorbell to deter porch package purloining, at Porton Down's new machine for training bomb-sniffing rats, at a smart bird feeder, at B&O speakers masquerading as books and at the development of paper-thin loudspeakers.
