Dr Anderson and his team have, of course, gone through painstaking efforts to rule out conventional physical explanations and systematic errors.

ECONOMIST: Physics

The HS2 line probably won't be comparable with the painstaking efforts made during the construction of the Athens Metro, but if HS1 is anything to go by, the archaeological considerations could still be huge.

BBC: HS2: 20 reasons why it can take 20 years to build a railway