Two conversations, one hour apart

In the car, driving home from work:

Duncan: "Mom, what does G-E-O-S-C-I-E-N-C-E-S-N-O-D-E spell?"

Me: "Geosciences Node."

Duncan: "What's that?"

Me: "Ummm . . . well, it's a place on the internet where you can get data that robots send back from other planets.  Mostly data about dirt and rocks."

Duncan: "What's data?"

Me: "It's . . . numbers that help you understand something."

Duncan: "Oh.  Why doesn't Mars have much water any more?"

Me: "Because it's really small.  Small things cool faster than big things, so Mars got cold and all the water froze a long time ago.  Also, Mars doesn't have much gravity to hang on to the water in the atmosphere."

Tristan: "Earth is bigger, so it has lots of gravity to hold on to its atmosphere!"

Duncan: "ACTUALLY, Earth has a magnetic field that protects the atmosphere from the solar wind!"

Me (quickly to prevent a fight): "Both those things are true!  Yes, you're both right!"

Duncan:  "Farmers have fields, but they aren't the same thing as magnetic fields."

Tristan:  "No.  They use magnetic fields to make the power.  The magnetic fields make the . . . power fields!"

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At home, immediately after dinner:

 Duncan: "NO TRISTAN!!"

Tristan, running through the house: (Incoherent screaming and sobbing.)

Me, rushing into their bedroom:  "Tristan, what happened?"

Tristan, lying on the bed:  (Incoherent screaming and sobbing.)

Dane, rushing into the bathroom, where Duncan is on the commode:  "Duncan, what happened?"

Duncan: "I bit him."

Me: "Tristan? Did Duncan bite you? Why did he bite you?"

Tristan, hiccuping, still crying: "I needed to pee!  He wouldn't let me pee!  He wouldn't let me!"

Duncan, still on the can:  "I bit him because I needed to poop!  I needed to poop and he wouldn't get out of the way!"