Science!

I’ve been watching the new Cosmos show, and they’ve been talking about the speed of light.  In a related sort of way, I told Allison about the speed of sound.  How it’s not instantaneous, but actually takes some time to get from here to there.  If we were standing far apart, you can actually see the delay.  I told her this over dinner one night.

The next day, we were driving somewhere, and she remembered our conversation.  She said “That doesn’t seem right.”  I was so proud of her skepticism.  I told her we’d do an experiment after dinner.

So, that night, we got out my binoculars and tripod.  We went out on our street, and I set up the binoc’s pointing as far as they could see down the street.  Then I ran down there (around 100 yards away), next to some trashcans.  I waved at Allison, and she waved back.  I saw her looking through the binoculars.  I banged on the trashcans a few times with exaggerated movement, so that she could see exactly when I hit them.  I waved again, and she waved back.  Then I jogged back to where she was, and I could see her jumping up and down with excitement.  “It worked!  It worked!” she yelled.  She explained how she SAW me hit the trashcans, but didn’t hear the sound until about a second later.

She wanted to switch positions, so we did, and I was able to see what she saw.  About a 3/4 second delay between sight and sound.

It was really fun and rewarding for me, and I hope the lessons learned (not only about sound, but about skepticism and testing ideas and gaining knowledge through evidence and experimentation) stick with her.