Saturday, September 24, 2022

Sita - 2

I could not get over Sita Ramam movie and I wrote what could've happened after the movie ended. If you've not watched the movie but intend to, give this post a skip 

“After bearing the cross of humiliation for so long, it’s so liberating to see Ram’s name getting cleared,” Sita thought to herself. She’s sitting on a dais flanked by the who’s who in the army. They’ve arranged a commemoration for Ram and the 41 soldiers that died in the air raids that followed Ram’s capture. Last few days have been taxing on her. So many people met her. Some shared their times together with Ram at the border, some, her sorrow. Right now, all she wants is a good sleep. It’s been a while since her nights weren’t punctuated by nightmares. The meeting finally ended with the national anthem. As she was about to exit the auditorium, she felt a hand on her shoulder. There was a girl standing behind her. She looked skinny and was wearing a scarf around her neck.

  “Do you know Ram?” She asked. “My dad worked in the same unit as Ram. He died in the air raid,” she replied passively. Sita turned around. “I know how it feels, I’m sorry for your loss.” She said trying to put her arm on the girl’s shoulder. The girl moved away instinctively as if something crept over her. “Stay away from me,” she said in a firm voice. “Your husband may have been cleared by the Army. But, he has blood in his hands. If he came back like others that day instead of searching for false valour, my dad would’ve been alive.” She said and left. Sita was reeling in shock. She thought her nightmares are behind her. But, this conversation disturbed her.

  She enquired about the girl with the people she met. Finally, when she met Lt. Ajay, she learnt her story. “Her name is Asima,” Ajay recollected. “Her dad Arif, Ram and I are from the same batch. We shared a very close bond. After Arif’s death, his family got shattered, both financially and psychologically. Despite showing a great promise, Asima couldn’t finish her studies due to lack of money. Her uncle moved from pillar to post to secure some compensation for Arif. But, in this country a peace time martyr doesn’t get the same value as someone who died in war,” he retorted. Sita thanked him for the information and left home.

She kept thinking about it for several days before she finally decided to approach the government. With the help of her contacts, she met with the defence minister. The minister invited her cordially and told her how proud he’s of Ram’s sacrifice. After exchanging pleasantries, Sita explained him her proposal to setup a fund to help the families of servicemen who died during peace time while on duty. The minister thought about it for a while and said, “I like the idea. However, we’re already in a fund crunch. Our soldiers are fighting harsh weather due to lack of good winter wear. Every year hundreds of soldiers die in skirmishes with terrorists. Setting up such a fund isn’t financially viable.”

Sita has never been someone to back down from a challenge. She recollected what her mom used to tell in her childhood. “You are a princess by birth, but you can only become queen by ruling the hearts of people.” She couldn’t bear to see the suffering these families are going through. She decided to sell off her ornaments and setup a scholarship for the kids of families affected by air raids. She personally wrote to all the families. While this gesture got appreciation, it hadn’t been of use to the most because it was too late. Her only consolation was that Asima took up on her offer to continue her studies. 

An year later, Sita went back to the minister and explained her about the scholarship. The minister was very pleased. “You’ve done something that I wanted to do but couldn’t. If you need any support, I am always there with you.” Sita’s eyes lit up. “Actually, I have an idea that can make this scheme sustainable. But, I need your cooperation.” The minister got curious. He invited her to his office the following morning.

Sita worked all night and chalked a plan. The department liked her idea and supported her in refining the idea. Finally, they passed an executive order implementing the scheme. Every year government allocates some budget to insure the troops. The insured value keeps changing every year to account for inflation. Her idea is to modify the scheme such that the insured value increases as per inflation but the sum given to the family in case of death remains the same. The insurance company will use a part of its CSR fund to supplement the difference amount and it is placed as fixed deposit in the name of the family who could use it only education purposes. In case, the soldier doesn’t have kids, the money is given completely. 

Next year’s commemoration saw the princess becoming a queen

 

Saturday, September 17, 2022

Qubit

 There’s a famous scene in The Big Bang Theory where Penny asks Sheldon if she should pursue relationship with Leonard. Sheldon explains Penny about the Schrodinger’s cat. It was a thought experiment proposed by Schrodinger to explain superposition in Quantum mechanics. So, what’s Schrodinger’s cat? Imagine a sealed box containing a cat and vile of poison. As long as the box is sealed, we don’t know if the cat is dead because the vile broke or alive. But, if we open the box, the vile of poison could break due to our action and kill the cat. It might not break and the cat could be still alive. So, as long as the box remains closed, the cat can be thought as being both dead and alive at the same time. This peculiar concept is called superposition. It is a key concept we need to know to understand about Qubits.

 

Wait, what’re qubits? Just as how classical computer works using bits, a quantum computer works using Qubits. Qubits are units of information which when measured can give one of the two states. For example, in the Schrodinger’s cat thought experiment, cat being alive is one state and it being dead is another. Let’s denote these states as |0> and |1>(This is Dirac’s notation to represent quantum states). Just as in the experiment, a Qubit can stay in superposition of both the states. What do I mean when I say it can stay as a superposition of two states? Imagine someone created a million copies of the same Qubit. If you measure the value of all the Qubits, some of them can become |0>, others |1>. The state of this Qubit can be represented by

 

S = a |0> + b |1>

 

Quantum mechanics states that the probability that measurement yield |0> is given by square of a and the probability of |1> is b squared. Since the measurement yields either |0> or |1> and probabilities should add up to 1, 

 

a^2 + b^2 = 1. 

 

Also, it is impossible to predict before hand if the measurement yields a |0> or |1> if neither of a nor b is 0. In the above equation, a and b are both complex numbers. So, a Qubit can technically be in infinite possible states even if the measurement always yields a |0> or |1>

 

Why should a and b be complex? Why not real numbers? The state of any entity(electron/photon/muon etc) is given by a wave function. We can imagine wave function as a function of position and time. What it means is that, the probability of finding an entity at a position depends upon the time when it is observed and position where we’re observing. In the young’s double slit experiment conducted with electrons(photons), these entities behaved as if they’re waves. Any wave is characterised by two properties, amplitude and phase. That’s the reason why a complex number is better suited to represent the coefficients of wave function rather than a real number as it represents two properties(real component and imaginary component). Alternatively, you can use two real numbers for each state(one cosine component and one sine component). We are choosing the former.

 

These Qubits are visualised using a Bloch sphere. What’s Bloch sphere and how to understand it will be discussed in the next post

 

Monday, August 1, 2022

A quantum aha moment

 Last year my friend forwarded an article which talked about advances made in 3nm technology. I remember studying that when process node reaches 3nm, each transistor could contain just 2-3 atoms and quantum effects become more prominent. As someone carrying a huge mortgage, this news worried me. What happens after 3nm? Will my job remain secure? So, I started thinking what other fields I could venture in. I thought, I am currently working on processors, so I should switch to a job of making quantum processors. How different can it be? Well, they are as different as a wormhole and an earthworm. 

 

An year since, I now realized that my field might not really end and I shouldn't have worried. Also, quantum processors and in extension quantum physics are really cool. I will describe an aha moment which made me fall in love with the subject. I came across a line which said, functions are points in an infinite dimensional space. Usually, if I don't understand a line, I just skip to the next line and try to get the gist of what the author is saying. That day, I made a resolution that I will try to understand every word and every line. So, I stopped. What does this mean?

 

So, let us take an example. Let us imagine a class of 40 students. We can now define a function which takes the name of kid as an input and gives the weight of the kid as an output. The normal way to visualize this is, you plot kids names on X-axis and their weights on Y-axis. If we do that, we get 40 points in a 2 dimensional plane. Imagine a 40 dimensional plane where each axis represents a kid. Let's say first kid's name is Rohit and his weight is 40KG. Then, x-coordinate is 40. Second kid name is Rahul and his weight is 35. Then y-coordinate is 35 and so on. So, the entire function now becomes a point in this 40 dimensional plane. If we extend this concept to real functions, each function becomes a point(vector) in an infinite dimensional space and each point in that space represents one function. This was such an aha moment for me. It's a beautiful way of looking at things. If this space of functions satisfies some special properties, it becomes a Hilbert space in which quantum mechanics operates(if you add two functions, the resultant function should be in the same space, if you multiply the function by scalar, it should belong to the space, additive identity should be part of the space, existence of norm. Fourier series is a well known example of Hilbert space. Why should it satisfy these properties? If these properties are not defined, we can never apply linear operations like addition on these functions and never logically prove anything).  

 

Okay, what did we achieve by doing this? Well, now let's take a function sin(x). It is a point in this space. If you differentiate sin(x), it becomes cos(x) which is another point in the same space. We know that we can transform any point(vector) to any other point(vector) in the space by multiplying it with a matrix. And boom! These matrices are called operators. If you multiply a function with a matrix, you get it's first differential. If you multiply it with same matrix n times, you get it's nth differential. Differentiation becomes an operator, integration becomes an operator and so on. Instead of dealing with functions, suddenly, we landed in Linear Algebra. 

 

Once a transformation becomes a matrix, it makes a lot of cool results possible. For example, quantum mechanics states that every entity can be represented by wavefunction which is some kind of oracle which contains all the information about the particle(entity). Now, if we want to find a measurable corresponding to this particle(momentum, position, energy etc), we find corresponding operator, find its eigen vectors and write the wavefunction as a linear combination of these eigen vectors. Corresponding eigen values become the allowed values for that measurable and the square of coefficients of these eigen vectors become the probabilities of the measurable being that eigen value.

 

I tried explaining the same thing in a different post on blog is much more shabby way. Please take a look if interested. Hopefully, I will explain more interesting concepts in more lucid way in future!

Sunday, July 31, 2022

A conversation with my younger self

 I came across an ad of JP Morgan on YouTube. In the ad, the man was asked about what he'd tell his younger self. It's probably very cliched question, but, it always brings out interesting answers. So, this post is my answer to that question

If I were to meet my younger self at fourteen, what'd I've told myself? At 14, I was in a school which ran till 7.30PM. To top that off, we used to have exams, every single day. I studied seriously for every single one of them to end up on podium(We had this ceremony where toppers were called on to stage and displayed like mannequins). I enjoyed the attention it gave me. So, I worked hard. At least, harder than I should've. I would tell my younger self to calm down and take it easy. In the end, it wouldn't matter. Instead, I'd ask him to make some friends for life. And, the soft skills you learn as a teenager helps you in the future.

If I were to meet myself at twenty, I'd tell him "College is the most beautiful part of anyone's life. Yours is no exception. Explore a bit more. Fall in love, fail in a drama, go on more trips. Form more memories. In the end, your internship didn't matter, all the projects that you did won't matter. Maybe study some subjects more!"

If I were to meet myself at 23, I'd tell him, "Time, like money is very valuable. Don't waste it on whatever idea appeals to you. You'll be better off doing nothing than work on something that's either too easy or too difficult. Relax, and have fun!"

These are my thoughts, what're yours?


Friday, July 15, 2022

Cogito, ergo sum

 “What’s something you know about the legendary Chitra Amma that the viewers don’t”, the anchor shot a question. “She always has the picture of her daughter while singing,” came the response. What a heartwarming answer! For those who didn’t know, Chitra’s only daughter died in a drowning accident years ago. I always felt sad for Chitra whenever I thought about that. What a horrific ordeal for someone who created billions of magical moments for millions across the globe. But, that day, a different thought struck me. Is the physical being that important?

Science tells us that we drown in a flood of emotions and sway in waves of sensations due to release of chemicals in brain. A hug from loved one feels great? It’s oxytocin. An answer to a tricky puzzle excites you? That’s serotonin. In fact, when this chemical balance is disturbed, it could lead to pathological conditions like Depression, anxiety etc.

If this is the case, if a person experiences pleasure in someone else’s memories, how different is it from their physical presence? An old couple whiles their time away in the memories of their children. An enlightened soul enjoys ecstasy in the feeling of His presence. If we extend this idea, is the physical being deserves the importance we attribute it to? Is someone ever dead? Maybe that’s why Descartes said, “Cogito, ergo sum”

 

Sunday, January 23, 2022

The Big Bang love

 They were together for an eternity. The idea of space and time didn’t exist between them. No bond in the universe exists as strong as the one that held them together. The creator got jealous of it. And, 13.7 billion years ago, he condemned them to a breakup with a loud bang. The reverberations of which can be heard even today. 

  They became the darkness and the light. Light followed darkness wherever it went only to dispel it. Darkness had to pave the way for the light to enter. This continued forever, until the light could no longer bear it. It went to the God and asked for the reunion. The God took pity on the poor lovers and granted them a boon. That his messengers will unite them wherever they are present.

  From then on, the entire universe became their playground. They met under the leaves of a tree, beside the trot of a horse, in the movements of the moon. Giving the world a lesson in coexistence.

Sunday, January 2, 2022

Musings over tea

 As I sip my tea on this lazy afternoon, I keep wondering what world problems I should try and solve. Poverty eradication has been my pet topic. I knew just the solution to eradicate the poverty even in my high school. Distribute money. However, to my dismay, I later realised that this solution might not work. I’m penning(technically typing) this blog post to discuss the problems I see, solutions I came up with. My hunch is, I’m going to read this post much later in life and probably bury myself in shame.

  What’s the problem with the Robinhood idea? It seems awfully similar to the idea of universal basic income which is being implemented at some places(Sikkim in India comes to mind). Let’s imagine that Government of India decided to give every person below poverty line Rs 12000 per month. In our hypothetical year, a devastating famine ravaged across the country and the production of rice and wheat fell drastically. In such conditions, even though everyone has cash available, they can’t purchase food to eat. So, it seems to me that the problem isn’t with money(At least according to the narrow definition of money we’re going to use in this post)

  One simple solution to this problem is to fix the price of essential commodities. In fact, we had a law to this effect till recently. The government could fix the price of essential goods to not exceed certain value. There are a lot of issues with this idea. This could lead to corruption and black markets. We’ve seen this in action during the peak of Covid Second Wave for essentials like Oxygen, Remedesivir injections. So, I believe this solution won’t work

  The only solution to this problem, in my opinion, is to increase production. We need to collect the usage patterns of people and produce enough to meet their needs. In fact, we do that in our country for all essential grains. We produce surplus of what we need for most of the essential commodities, thanks to green revolution. We distribute these essentials through ration shops. Lately, we’re going back to UBI idea by transferring cash directly to accounts. There are some advantages with UBI(it cuts out the middle men, offers choice to people to consume food they like and so on) But, I believe it might have bad repercussions in exigency situations.

  Does it mean we’ve solved the problem of poverty in India? I’d say no. Food isn’t the only essential commodity. We need to provide house(hence PMAY and other housing schemes), sanitation(Swacch Bharat), health(Aarogyasri, Ayushman Bharat etc), education(Scholarships, mid-day meal scheme, etc), financial inclusion(Access to credit & savings facilities(Jan Dhan yojana, postal saving scheme, OD facilities, micro finance institutions etc), insurance, investment opportunities), internet and so on. I think, Government has come up a huge number of schemes to eradicate poverty. However, it’s the awareness of these schemes and delivery that is found wanting. Let’s hope that will change in years to come and I think about a different topic over tea next time.