In this episode of the Physics World Weekly podcast, four physicists at the University of Birmingham explain how they used two clouds of ultracold atoms as a portable gravity sensor. Their device was able to locate a small tunnel on the university campus and can be used outdoors – and impressive feat because the atoms were held in ultrahigh vacuum and millikelvin temperatures.

Also this week, Physics World editors chat about recent breakthroughs in physics including the first mass-produced silicon spin qubits and a surprisingly heavy W boson.