Here are some of my faves from a facebook thread:
"Science is true, whether you believe in it or not." (-Neil deGrasse Tyson)
"What do we want? Evidence based science! When do we want it? After politician (imagine that's strikethrough) peer* review!"
"Ice has no agenda. It just melts."
"The scientific method does not include your shitty politics."
"Climate change: No party. No borders. No exceptions."
"Tomatoes in December? THANKS, SCIENCE! The internet in my pocket? THANKS, SCIENCE! What's smallpox? THANKS, SCIENCE!"
"Revenge of the nerds!!!"
"Science: it works, bitches."
"There's no room for alternative facts in science."
"Science > Your Opinion"
"You know it's bad when the introverts reach their boiling point."
"Don't silence science."
"Political ideology can corrupt the mind, and science."
Buy poster boards now! Many cities ran out before the women's march. Or use cardboard boxes for less environmental impact.