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One day while teaching, Josh was asked, ”Teacher, if the time of day is an arbitrary number we can change as we need to, how can we agree on what time is at all?”
Josh spoke thus:
A child asked a grandparent, “What time is it?”
The grandparent replied, “It’s autumn time. Look at how pretty the leaves are. They’re red, and they’re yellow, and they’re orange. Every year the the leaves change colors in autumn time.”
“I know it’s autumn time,” the child said to the grandparent, “Everybody knows it’s autumn time.”
“It’s not autumn time in Argentina,” the grandparent said to the child, “In Argentina, it’s springtime. In Argentina, the first leaves of the year are beginning to bud. There are new flowers rising out of the ground, there are young rabbits coming out of their holes. There are lambs in the fields.”
“We’re not in Argentina,” the child said.
“So then it’s fall time,” the grandparent said.
“I don’t mean what season is it,” the child said to the grandparent, “I mean what time is it.”
“It’s evening time,” the grandparent said, “The shadows are long. The birds are returning to their roosts.”
“I know it’s evening time,” the child said, “Everyone knows it’s evening time.”
“It’s not evening time in France,” the grandparent said, “In France it’s nighttime. In India it’s morning. In China it’s midday.”
“I don’t want to know it’s nighttime in France,” the child said, “I don’t want to know it’s morning in India and midday in China. I want to know what time it is here.”
“Well, let’s take a look,” the grandparent said. The grandparent led the child to a sundial standing in the garden. “It seems to me, looking at this sundial that it’s sometime between early evening and late evening. See how the shadow moves around the face of the dial? The sundial is the basis of our system of time.”
“I know it’s sometime between early evening and late evening,” the child said, “I want to know what hour it is.”
“Look at my watch,” the grandparent said to the child, “See how its face mimics the face of the sundial? It’s the same time on my watch as it is on the sundial.”
The grandparent showed the child how the watch face mimicked the sundial. The grandparent showed the child how the position of the hour hand on the watch face was the same as the position of the shadow on the sundial.
“There are no numbers on your watch,” the child said.
“There are no numbers on my watch,” the grandparent said.
“So how do you know what time it is exactly?” the child asked.
“I don’t need to know what time it is exactly,” the grandparent said, “I just need to know what time it is.”
“But what time it is exactly is what time it is,” the child said.
“Well, then,” the grandparent said, “Just for you, I’ll see what time it is exactly.”
The grandparent took the child inside to show the child a special computer the grandparent had. The grandparent showed the child the time synchronized to atomic time and the time synchronized to GPS time. The grandparent explained the difference between atomic time and GPS time.
“So why is it so important to know what time it is, exactly?” the grandparent asked.
The child replied, “Oh, I just wondered.”
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