“Hee Haw!” Enters Goofy Crackedjaw… He must have made an adventure with his surf-boat today.
“Hey guys! Dare to surf a 40 feet giant wave? None of you have that damned guts.”
Jane: “How stupid! I look better with my jaws intact rather than to have odd guts to sacrifice it for a poor wave.”
Goofy had his jaws cracked when he was tossed into a shore rock riding a big wave… he is a talented surfer but sometimes he underestimates the power of a wave and overestimates his skills. So we call him Crackedjaw Goofy.
Goofy: “You’ll never get that ‘out of earth’ experience ‘messedup Jane’… what you cooked today cockroaches for chicken?”
Oh yes! Jane is a girl of 18, she studies physics and known for making mess in the kitchen, in the market place… as her mom says “she has always been so nice, talented… err… but messy, like once she had poured gasoline in the flower tubs and water in the car!”
Jane: “You’ll have to pay for your sins Goofy; I warn you, don’t jeer at me that way.”
Me: “Guys stop fighting; I have got news for you mates”
Jane: “Hey what’s that… Has another Goofy died surfing a wave?”
Me: “Come-on Jane, spare him now… Do you know our coasts are on high alert for Tsunami? Forecasters are expecting a tsunami within 12 hours.”
Goofy: “Hey Jane I’ll mark a new world record surfing the Tsunami… it’s your last chance to meet a celeb Jane. I’m ready with my boat let that tsunami come”
Me: “Beware Goofy! This time you may Goof up with your life … It is not a wave that can be surfed, we must move highlands for safety.”
Goofy: “Well, I’ve surfed giant waves taller than a 5 storey building… and what the hell is tsunami?…”
Me: Tsunami is a wave.
What is Tsunami?
Tsunami is a water wave that is formed due to displacement of a large amount of water. Such voluminous displacement is generally affected by an underwater earthquake, landslides or meteorite impacts.
Well, for Jane such definitions won’t work as she likes more formal definitions so to put it for her: A tsunami is a shallow water gravity wave that has a large wavelength and small amplitudes in deep water, however, as the wave moves to shallow water the speed of the wave decreases and its amplitude increases tremendously.
Behavior of these waves is greatly different from the wind waves or the normal sea waves that surfers usually encounter.
Jane: “I see, this definition sounds familiar; I have read about water waves in deep seas and their behavior in the shallow water. They are mostly non-linear waves.”
Goofy: “Big Words! So what the hell I’m doing here it is better I wait for the high waters in the sea.”
Me: “Hey Jane don’t go that deep coz you know our good friend Goofy is a surfer…he likes to stay on the surface… and big words make him sink… :D”
Goofy: “Not like that… I am interested in learning stuffs provided they be put in plain… not like Jane’s geeky words. Okay, now what causes Tsunami, how do they propagate and how are they dangerous”
Me: “Good questions Goof… well first you must know what a wave is… that is physicist’s wave”
Goofy: “Ok what actually is a wave then?”
Me: “A wave is a periodic disturbance. That means the motion/disturbance would repeat itself after an interval of time.”
Even a child knows how to draw a wave, the difference between physicist’s wave and a child’s wave is: physicists give the waves and its parts some names (known as wave profile) and they try to relate the various parts mathematically for calculation purposes; that makes it appear alien.
Quantities like wave length, Amplitude or the maximum wave height, frequency or the number of vibrations made in 1 second, phase etc are called wave profile.”
A Physicist’s wave:
Goofy: “I see, it’s so simple… I am gonna read all of Jane’s books”Jane: “Someone had rightly said ‘A little knowledge is a dangerous thing’”
Me: “Guys calm down. Well, let’s see how a wave is generated… so that we can understand the mechanism of Tsunami generation. Goof and Jane hold on the ends of this 5 meter string, and then one of you shake it up and down… what can you see?”
Goofy: “Yoo! I can see a wave in the string moving towards Jane.”
Jane: “Goofy can you say what is moving towards me here?”
Goofy: “I am not a retard not to know the answer for such kinky questions.”
Me: “Goof! Answer her; this would let you know a lot about waves.”
Goofy: “KK, simple the wave is moving I can’t see any other objects to be moving towards Jane… do I? Yep, I can see the string move vertically up and down”
Me: “Great, a good observation from Goofy, the particles of string are moving up and down but are not moving forward towards Jane. This means particles of the medium (here it is string) under the influence of the wave don’t move forward with the wave. Thus, what moves through the wave is the energy.”
Goofy: “Energy?”
Me: “Yes, energy, the ability to do work… see you have got the ability to move the string up and down this is evident as your hand is moving up and down but can you see this up and down motion has reached at Jane’s end of the string, thus your ability of making the string move up and down or doing the work is being transferred at Jane’s end of the string via waves. Thus, waves transfer energy.”
Goofy: “I see; it’s simple.” (Jane Frowns)
Me: “Ok Goof, just match the waves in the string with the physicist’s wave and try to identify the wave profile: amplitude, wavelength, frequency. And draw them on a paper.”
Goofy: “I have got a question…well it seems that waves don’t carry the particles of the medium along with it… but from my experience as a surfer quite a lot of times I have seen waves to carry a good deal of water forward with it. How would you explain this?”
Jane: “It’s simple… okay have you seen the water brought by the waves recedes away with the wave too? A sea wave is a lot more complicated than string wave… in string the particles of the string are seen moving up and down that is moving perpendicular to the direction of motion. But in sea waves the particles of motion move in circles or ellipses, that is you may say it is a combination of vertical up and down movement with horizontal to and fro movement. So we can see sea waves moving up and down and still brings water with it.”
Me: “Exactly, but it is also possible that the particles of motion never get back to the actual positions after course of the wave… These are non linear waves… a bit complicated for you to learn just now Goof.”
Goofy: “Okay! So it needs a good deal of knowledge to understand Tsunamis.”
Me: “Yes, because water waves are far more complicated than other forms of waves like light etc.”
Jane: “So Goofy drop your idea for surfing Tsunami of which you don’t know at all.”
Goofy: “Okay as you say.”
He heard to her for the first time.
To be continued…
