"What will my child’s world look like in 30 years?” That’s the resonant question asked by a speaker at the Mall in Washington at last weekend’s March for Science. She is under a roof. I’m not, and I am drenched. I look around. A girl is wearing a blue poncho on which is written, I wear this because science told me it was going to rain today. Next to me stands a man holding a hand-scrawled sign: Keep the oceans clean. On his chest, wrapped in a yellow towel, a baby licks the rain off his lips.