When hairdrying your hair, one hand (the hand you ruffle your hair with) gets warm due to the warmth of the air blowing out of the hairdryer, and one hand (the hand holding the hairdryer) is cold.
One of my hands is hot and one of my hands is cold!
British slang for a scientist or technical expert, esp . when the speaker is not certain of the expert’s specific field of study. Not necessarily derogatory, but typically used by persons without a technical background. In the US, the equivalent would be “egghead”, “squint”, or “geek.”
Origin of the word is unknown. Started sometime in World War 2. Given the typical evolution of British slang, could easily have started because what these experts did was confusing or “baffling” to the common person.
According to the boffins downstairs, the murdererused a serrated blade.