Below, you will find a fictional dialogue between two unusual friends – Justin and Justina. In this conversation, they ponder why the TV weatherman would forecast a 5% chance of rain. Is there a hidden meaning? To find other philosophical conversations between Justin and Justina, please see our series.
Setting the Stage I
Justin and Justina are both at their respective homes, communicating via text messages through Element messenger (this post is sadly not sponsored by Element messenger).
Act I: What is a 5% Chance of Rain?
Justina: So, I’m going out tomorrow.
Justin: Be careful of rotting pumpkins. Just saw one today. Pumpkin Taker is slacking.
Justina: I’m serious!
Justin: I wish Pumpkin Taker was.
Justina: So my weather app says there’s a 5% chance of rain.
Justin: I see.
Justina: Should I bring an umbrella? Just in case? I mean 1 out of 20…
Justina: Really? But only a 5% chance.
Justin: 5% chance of rain means 50-50.
Justina: I don’t think so…
Justin: You need to think about this from the weatherman’s perspective. Basic game theory.
Justin: 5% chance of rain is a no-lose situation for the weatherman, right? If it doesn’t rain, he’ll just say “well there was only a 5% chance.” But if it does rain, no one can be angry at him. He’ll say “well I said the chance was more than 0.” You see? He has us all where he wants us.
Justin: If it really wasn’t going to rain, he’d say 0. But he’s hedging. Probably 50%. He wants to teach a lesson to all the people who foolishly mistake 5% for 0 chance of rain.
Justina: I don’t think what you said makes sense, but 5% isn’t 0, so I guess I’ll bring a small umbrella just in case.
Justin: You’re very welcome.
Setting the Stage II
For the next evening, we find Justin and Justina again at their respective phones, communicating via Element messenger.
Act II: Respecting the 5% Chance of Rain
Justin: What? Did you have a good time?
Justina: Yeah, I did. I was the only one who brought my umbrella. We got caught out in the rain and my friends got soaked until we found this cool place called The Emu Café. Your nonsense about weatherman conspiracies actually turned out to be useful.
Justin: No problem, it’s what I do. I got soaked while I was out for a walk. 5% chance of rain man, what are the chances? Life is a coin flip.
Justina: …Then what was your whole spiel yesterday?
Justin: Oh that? It’s all true, but what’s the worst that can happen to me? I didn’t melt. Not like the decomposing pumpkins, to be sure.
Justina: This serves you right.
Justin: I can handle that from you. But I’m not reading any weather reports tomorrow. I won’t give the weather-industrial complex the satisfaction.