We have two mobiles that we hang up in Jeremiah's crib sometimes. One is a simple series of black and white geometric designs on cardboard that just dangle there. It's designed to stimulate a growing baby's mind or something; all I know is that he likes it. He looks at it, he talks to it, it absorbs his interest for ten minutes or so. Then, apparently unable to tear his eyes from the stark patterns dangling overhead, he gets overstimulated, starts to twitch insanely, and we have to take it down.

The other mobile is pictured above: four plush celestial bodies circling a smiling sun. They hang from a rotating musical box that plays Brahm's lullaby (I think all music boxes for crib mobiles play Brahm's lullaby), so the planets and stars slowly orbit the sun. Jeremiah loves this thing. He fixes upon different parts of it and tracks them as they swing around. It's like baby TV. Unfortunately, the music box runs down after about three minutes and if the mobile stands still for more than a few seconds, Jeremiah gets all worked up and freaked out, so we have to keep running in to wind the thing up again. Still, it's a way of keeping him happily occupied for a while, and as soon as he hears the music start up he gets so happy that it's beautiful to see. With this mobile, he's good for about five rewindings of the music box before he gets overstimulated, starts to twitch insanely, and we have to take it down. In the above photo, he looks as if he's maybe on rewind number four or so.

From the other room, I heard Jeremiah fretting in the crib, calling my attention to the fact that the music had run down so the mobile was standing still. I went to the crib and Pär wandered over to stand next to me.

"Do you know what would happen," he asked me, "if the real planets all stood still like that?"

"Uh uh," I said, rewinding the music box.

Brahm's lullaby started playing again. We watched the baby's face light up at the sight of the mobile in motion.

"The orbital balance between kinetic and potential energy would be utterly destroyed. They would all start accelerating toward the sun in a straight line."

I turned to the mobile, poked at the big stuffed Earth. It swung toward the sun, bumped into it and sent it swinging to bump into the pink fuzzy Saturn on the other side. All the celestial bodies swung back and forth wildly.

"Like that," I said mildly.

"Oh honey!" Pär said, and hesitated. He made a heroic effort to let the joke pass, shifting his weight from foot to foot and smiling uneasily, but was finally unable to stop himself from correcting the science. Words burst out of him. He gesticulated wildly with his hands. "First of all, if Earth was hurtling toward the sun, it wouldn't bounce off it."

"No?"

"No..."

"It would... burn up," I hazarded.

"Civilization would go up in flames and everyone would die within... hmm, that's an interesting question. Would it take a couple of hours, or a couple of years?" His face took on that abstracted look.

"So you're saying this," I flicked my finger at the fuzzy blue moon, bounced it off the lumpy Earth, "isn't an accurate representation of the physical laws of the universe. Is what you're saying."

Pär was still caught up in trying to figure out how long it would take the Earth to be destroyed by the sun. "No..." he said.

I looked at him until his eyes refocused on me. He saw my expression of polite inquisitiveness, and did that blinking concentrating mad-scientist thing where he's trying to remember the conversation we just had.

"Civilization go up in flames, that's a good one," I said. "You and your silly --" I made little quotation marks in the air with my fingers, "-- 'Science'. Next you'll be telling me there's no big smiley face on the sun."

Today is my first Mother's Day as a mother. Pär went out to the gym early in the morning while Tot and I slept in. When he came home, I was on the phone with my own mother. Without interrupting the conversation, he handed me a large covered cup from his favorite coffee place: when he stopped in to pick up a coffee for himself, he'd also gotten a hot cocoa for me.

As I got off the phone I said "Happy Mother's Day" to my mom. Pär, hearing this, winced and then looked sheepish.

"Damn! I remembered about Mother's Day all week, right up until today," he told me. "Then I forgot. I'm sorry..."

And all I could think was how glad I am to have a lover who would bring me hot chocolate in bed on a Sunday morning for no special occasion at all.