International dateline and grandma!

Sitting on the flight from Bangalore to San Francisco, I pondered over how I would explain the time-change concept to my grandmother. May be, the conversation would go as follows. Grandma asks, “When are you leaving for America?”

“My flight is in the afternoon grandma, at 2 pm. I will reach America at 6 pm on the same day!”

Grandma was puzzled. “How can you reach America in 4 hours? In 4 hours, you can reach only Tiruvannamalai!”

Once I started explaining about time-change, I was tied up in knots. I used my left fist as the earth and my right palm as the plane.

“Grandma, the earth is rotating like this!” and moved my fist clockwise. “This is the plane!” and moved my right palm anti-clockwise.

Grandma interrupted me. “Your grandpa had multiple opportunities to travel abroad. He didn’t take it up. In those days, crossing the ocean was barred.”

“But grandma, you can go to America without crossing the ocean!”

I elaborated, “Grandma, I will start walking from Chennai. I will walk to Kolkata and then to the North-East. From there, I will go to China. From China, I will walk to Mongolia. From Mongolia, I will enter Siberia. From Siberia, I will cross the Bering Strait by boat and reach Alaska. From Alaska, I will walk Southwards, cross Canada and finally touch San Francisco! Bering Strait is the only water body, but that is as narrow as our Palk Strait!”

Grandma asked, “How long is this trip going to take?” I replied, “Maybe a few years!” Grandma had practical questions. “In this padayatra, who will serve you curd-rice?” “Grandma, no curd-rice! I will eat some animal- maybe, a bison for breakfast and moose for dinner!” Grandma was blunt. “You need curd-rice for every meal and now, you will eat a mouse?”

I went back to the original topic. “Grandma, my plane will go Eastwards from India. As the earth rotates, I will travel deeper into the night. Soon, I will reach morning before morning reaches India!”

Grandma asked, “It will then be the next morning, isn’t it? How can you reach America on the same day?”

 “Grandma, they have drawn a line called “the dateline”. Once you cross that line, they count it as the previous day!”

“Who has drawn this line?”

“It is an imaginary line grandma!” I replied. “If the line is imaginary, then, considering it as the previous day is also imaginary, isn’t it?”

“Yes grandma,” I stuttered.

Grandma suddenly swerved from the topic and quoted from an ancient text, “What is night for us, is day for him. What is day for him, is night for us! See! They knew about America back then!”

“Yes grandma!”