To follow the story-line click on the link below for the first part:
May 31st 2016
“Based on my calculations, we are moving at a speed of 14 km/hr. We will arrive with enough time to spare,” I screamed optimistically against the sound of the motor threatening to drown my voice.
Flaw( I am sure there might be more) pointed out by a friend: Even the slowest motor boat in the choppiest of water moves upto 50km per hour as far as ‘Google’ knows. Thank you, Sudarson for your long critical remarks.
Uncle rolled up his long sleeves before turning his head sideways towards the banks of the river. I could see him smile.
“Varvara, I have never expected such sloppy language from you. What do you mean when you tell me that we are moving at a speed of 14 km/hr? Explain yourself.” He kept his gaze fixed on the banks as he spoke.
I looked at him, questioning my own conceptual understanding of speed. There seemed to be no error in the statement I had made. Was this one of uncle’s tricks?
“Your calculations are based on speed with respect to still water but you have not considered the water current. Depending on whether we are moving with the current or against it, the value of the speed varies. Remember motion is relative. If there was a cyclist moving at a similar speed of 14 km/hr on the banks of the river in our direction, we would appear stationary to him and he would appear stationary to us even though both of us are moving. In a likely event, wherein, the poor cyclist slows down due to exhaustion, his perception of motion will change. We will no longer appear stationary to him. In describing any kind of motion we should always have a reference frame.”
“What is a reference frame?” I asked.
Uncle leaned forward and picked up a small pebble lying in the corner of the boat. He picked it up and dropped it.
“How would you describe the motion of the pebble in the air?”
“The stone traces a straight line,” I answered hesitantly with a hint of doubt.
“It traces a straight line(as long as the boat is not accelerating) but for a person sitting on those banks the pebble traces a curve. By virtue of the observer’s lack of motion, he perceives the stone traversing a parabolic curve. The above observations made are both true but it leads to another question. Does the pebble trace a straight line or a curve ‘in reality?’ This is the reason describing motion ‘in space’ is not an easy task. Space seems like an ambiguous term of which, I confess to have not the slightest fathomable idea.” He paused, escaping into a reverie of sorts.
I wish I knew what he was thinking. Only on very rare occasions was uncle rendered taciturn.
“Do you remember our visit to Greece?” he suddenly broke the silence; although the creepy sounds of the crickets did not exactly account for complete silence.
How could I forget Greece? It was the first time I had boarded an aeroplane but my excitement was soon taken over by unexpected motion sickness, consequently ruining any prospects of what people would call a “happy journey”. I blame the nachos.
“You ate nachos on the flight and watched a movie. Which one was it again?”
“Piter FM. I must add, a great movie with an unexpected ending. Masha’s cell phone slips from Maksim’s hands and falls into a river under the bridge when he tries to get her number. How could they end it on such a note after building it up for two hours?” I pouted as the memories of the movie lingered around.
Uncle laughed before he declared it was my turn to row the boat. He handed over the pair of oars to me before he dipped his hands in the ice-cold water. The motor had stopped working and we had to use the emergency pair of oars on the boat.
“I will present to you two cases. You are watching Piter FM while travelling to Greece, eating a plate of nachos. The window shutters are down. This flight experiences no turbulence; an extreme case. In the second scenario, you are at home doing the same. Do you think you would you ‘feel’ different at home as compared to a uniformly moving aeroplane? Would you be able to ‘feel’ the motion in the former case as opposed to the later? Perhaps a child back on earth, flying a kite, would ‘feel’ the aeroplane in motion and dream of becoming a pilot someday. According to the child, the aeroplane certainly does not appear still. However according to the passengers in the scenario I described the entire surroundings move along with them, hence distorting the idea of speed.” He concluded before leaning towards his left side to indulge himself in one of his childish antics.
“In Arabic, there is a word for the amount of water that can be held in one’s hand. It is quite conceivable; the need for such a word among people who have traditionally lived in water scarce areas. But I interpret the word differently. Gufra signifies the little knowledge we have today with respect to the vast amount of unanswered questions left to explore. In other words, we are still trying to find a way to an oasis.”
He exhaled deeply before he let the water slip past his fingers. We spent the next minutes thinking in silence. I kept going back and forth in my mind, struggling to conjure everything he said. Something did not make sense.
“According to what we have learnt so far, motion is relativistic and different with respect to the reference body used, hence the concept of relative velocity. How then, can light have a constant speed? Is light an exception?” I asked.
“I will show you the answer in the laboratory. At the moment I recommend basking in the warmth and splendour of this sunlit landscape.” He almost recited in a dramatic tone.
“Can I ask you one more question? It is quite a silly one but it has been bothering me for quite a while.” I spoke softly, letting the crickets win in a ‘battle of the loudest.’
He nodded approvingly.
“When the Flash (DC Comics) runs so fast relative to other “earthlings” why does time slow down for him?”
“Although I have not read the comic books, the concept you are referring to is called time dilation. I want you to learn about it yourself. There is a young chap, I reckon a brilliantly foolish one, on the internet who has posted a wonderful article with a small thought experiment called the ‘Parable of His Holy Balls.’ You must read it.” he said before he looked at his watch.
It was dusk.
The last gleam of light dancing on the water as day turned into darkness.
I think the boat remained motionless for a while, or we must have drifted along with the current. Either way the speed of the boat was the least of my concerns.
The next day, Uncle Pyotr sent Varvara the following link: