Dr Chris Smith and the Naked Scientist team present the latest science news, analysis and breakthroughs. In this week's episode…. Scientists show that when two people talk, their brains really do sync up. Bird flu is now spreading among cattle via their milk. So what are the implications of that? A new scientific twist for better, more efficient fog harvesting to keep arid areas better watered. Plus our Titan of Science this week explains dark matter and how we know it's out there. Get the podcast from the BBC Sounds app.