After leaving Russe I cycled for two days down through northern Bulgaria, whose green, rolling countryside - and the resemblance is too striking to pass without comment - reminded me of Britain.

We hold that the IMF should mobilise resources through the quota-based system as well as voluntary contributions, striking a balance between the rights and obligations of the contributing countries.

As the particles hardly interact at all with other matter, they stream right through the ground, with only a very few striking the material in the detector and making a noticeable shower of particles.