Steve Caplin and Simon Rose marvel at new search engine Perplexity which they both feel knocks Google for six in its usefulness. You can try it at Perplexity.ai for free on the web and through apps. Google have other problems too, with their new campus a wifi black spot. A helium balloon could be the answer if you're lost in the wilderness. A watch could show you your actual blood flow. Bionic eyes could be powered by solar panels on the iris. A replica of the Titanic is due to sail in 2027. And there's a sweet crowdfunded robot powered by your smartphone.