Two Nobel laureates and other top scientists are accusing Boris Johnson of destroying Britain’s global reputation by behaving “like a clown” and pursuing a no-deal Brexit that would leave UK science “dead” for years. The government has assured anxious academics it still has a clear ambition to join the European commission’s new €100bn (£89bn) research funding programme, Horizon Europe, after Brexit. But Robert-Jan Smits, the commission’s former director-general of research, says the UK has “zero chance” of negotiating associate membership…