(soft music) - Hi everyone. And welcome back to Conversations at the Perimeter. I'm Lauren. - And I'm Colin. - And today we're bringing you a conversation with Meenu Kumari, a postdoctoral researcher here at Perimeter Institute who specializes in quantum chaos. - Quantum chaos. You know, that's a term that I actually haven't encountered before our conversation with Meenu, despite talking to a lot of theoretical physicists, that, that idea of quantum chaos was, was new to me.
And I was fascinated to hear about it because when I first heard it, honestly, it sounds a bit like something outta science fiction. - Well, Meenu has actually been a friend of mine for many years now, but I still learned a lot from this conversation about her life, her journey to where she is today and her research in the quantum to classical correspondence and really studying how we can move between these quantum and classical realms.
So without further ado, let's dive right into the quantum chaos. - Meenu Kumari. Thank you so much for joining us here at Perimeter Institute in our, in our beautiful but empty theater. Thanks for joining us. - Thanks a lot for having me. - So Meenu, thank you so much for sitting down with us today. I'm really excited to talk to you. Maybe you can just start by telling us what you do here at Perimeter, what your role is, and also what you're interested in studying.
- I'm a postdoc in the quantum information research group at Perimeter. I joined in September, 2019, and I did my PhD at IQC at the University of Waterloo from September, 2014 to August, 2019. - So IQC, that's the Institute for quantum computing, just down the road from here. So is quantum computing part of, of what you do? You're a theorist. - Yeah. - And quantum computing sounds like it's for machines. So can you explain how you're connected to quantum computing?
- My field, my research is in the field of quantum information, using the tools and techniques of quantum information to study other questions in physics.
The thing is quantum computing uses quantum information techniques or for quantum processing techniques to build like quantum computer, like so many tools and techniques have been developed in the field of quantum information, which can be used in other fields of physics, like high energy physics, or (mumbles) metaphysics to study other questions. So quantum information is basically like world is fundamentally quantum, right?
If you-- - Oh, so, just to interrupt the world is fundamentally quantum in the sense that at the underneath everything, quantum mechanics sort of describes how, how the world works at this small level. If you dig deep enough into anything you'll get into the quantum realm. Is that fair? - Yeah. So the thing is like first classical physics was developed, which is like Newtonian mechanics, Galilean relativity and then Hamiltonian mechanics and so on.
So those theories describe the world at the macroscopic level very well, actually. But towards the end of 18th century, like around 1890 or something, there were so many phenomena that, that we are discovered experimentally, which, which were not, which the physicists were not able to explain using the Mecca, using the formulation of classical physics. So they started to dig into what's going on, trying to understand, for example, for the photo electric effect.
Around 1920 to 1930, this new formalism of quantum mechanics was developed. And over the years, we have seen that whatever we can predict from the theory of quantum mechanics, most of the experiments that we do today, the results of those experiments can be explained using the theory of quantum mechanics.
So that's the thing that the world is fundamentally quantum because almost all the experiments at the microscopic level, or at atomic level basically, can be explained using the, using the theory of quantum mechanics. Although the formulation of quantum mechanics is, is quite non-intuitive. - So I have a question there. - Yeah. - So as you started to allude to, there's so many research fields that people work in now that are studying different quantum properties of matter.
So you mentioned quantum information, quantum computing, there's also quantum matter, quantum foundations, quantum field theory. There's probably a lot of other fields that have the word quantum in them. So can you just tell us a little bit about that word "quantum" and really what are some of those quantum features that are so interesting and confusing as opposed to the features we might be more used to in classical matter?
- Yeah. So two of the most intriguing features are the principle of superposition and the principle of entanglement actually, Schrodinger's cat is a famous example. Unless until you look at it, you don't know whether the cat is dead or alive. So. - I'm, this is, this is the famous thought experiment with the cat in a box. And it's a, it's a sort of metaphor for things that can be in one state or another at the same time until they're measured. So you don't know if this cat.
- Yeah. - I, when I was younger, I thought that was a real cat in a real box and a real experiment. I'm glad to know it's not. (laughs) So that explains superposition, this idea of things in the quantum world being in a state that's more than one thing. - Yes. - At the same time. - Yeah, that's right.
So for example, if you take a quantum coin, a classical coin is either in the state of heads, like if you flip it, it is either heads or tails, but quantum coin can be in a superposed state of heads and tails, and then you measure it and you will get either heads or tails out of your measurement result. By measuring it again and again, you will find probabilities of getting heads as well as tail and using that, you can construct the quantum state.
So the quantum coin is basically in a superposition state. It is not just only in heads or in tails. Like quantum mechanics isn't a simple theory. It's not, it doesn't describe one single instance of a particle or something. Like it describes, like if you do something over and over many times, what will be the output that you'll get, like what will be the probability of getting. - It works more in likelihood and probability than an exact prediction. - Yeah, that's right.
So if you just measure it once and see whether it is tail, heads, you can't really say that it, whether it is in the superposition state of heads plus tail, or whether it is really heads, you will have to perform the measurement on the same copy, on the multiple copies of the same quantum state again and again to figure out whether it is in a superposition state or not. - This is part of what confuses a lot of people about quantum mechanics, right? This is 'cause we don't experience that.
When we flip a coin, it's always heads or tails. - Yeah, that's right. - Cause it's a, it's a macro world coin. So it's okay that people are confused by this, right? It's not something we experience. - Yeah. It is very non-intuitive, like we don't really observe anything in a superposition state. So that's where quantum foundations come in. We describe a quantum particle using a wave function, which can be in a superposition state, but we don't really observe that wave function.
What we observe is probabilities of certain kinds of observables, like any real observable, for example, for, with this coin, when you measure it in the basis of head, head and tail, when you measure it, whether you'll get head or a tail, actually. So quantum foundation is like trying to understand what is real versus what we infer out of measurement.
So this whole (mumbles) mathematical formalism of wave function is a mathematical construct because we can't see the wave function (mumbles), right. That the quantum particle is indeed in that state. We can only infer observables, measurements of observables actually. - Right. - So quantum foundations deals with trying to understand what is real versus what we can observe. Like what is the connection between those two.
- And I just wanna go back to something you, a word that you said a few sentences back, you were talking about trying to measure these quantum states. And you've talked about doing that on many copies of the same state, but I think that word copy is maybe something we should talk about because I think there's another interesting property in quantum mechanics, but you can't actually make an exact copy of a state. Is that right? - You can, you can't make an exact copy of an unknown quantum state.
So that's no cloning theorem actually. Like once you know what is the quantum state mathematically, you can prepare many copies of it. But if you don't know what is the quantum state of a particle, you can't copy it. And that is a principle that is, that would be used in many different types of applications of quantum information and quantum computing, actually like quantum cryptography. - And that's different than in classical cryptography. Is that right?
- Yeah. Like you can create copies of something basically in quantum, classical cryptography without other people knowing about it actually. But quantum state, like as soon as you measure, the quantum state of particle is destroyed actually. So once it is destroyed, the other, the receiver end will know that it has been intercepted by, by some Eve actually.
- Is that the quantum cryptography or the idea of quantum encryption that measuring a quantum state changes it and therefore you can detect whether it's been measured? - Yeah, that's right. - So, and that's a, that's sort of a branch of quantum computing and quantum information. I wanted to get back to that 'cause you said you work at these intersections of quantum information, which is related to quantum computers, which are in theory, these very powerful computers that harness superposition.
And, but you said you're at the intersections of quantum computing and quantum foundations. So which questions are currently sort of the focus of your attention? What are you trying to figure out? - I became interested in, in chaos actually. So initially I did a few projects in my, during my undergrad studies in the field of classical chaos. And then I did a project in the field of quantum chaos.
- So can you actually just start by telling us what classical chaos is maybe before we, I know that's not really what you work in, but it might be useful to start there. - Chaos is a pretty loaded term, non scientifically, but chaos is a very specific meaning in your. - Many people would be familiar with the term butterfly effect. So it is like if, can the flap of a, of the wings of a butterfly in Brazil cause a tornado say in Germany.
So that's the butterfly effect, can very small changes in the initial conditions lead to vast differences in the outcome. Chaos is basically unpredictability due to sensitivity to initial conditions. Like the seeds of chaos theory were sewn by Henri Poincare, but then it was well formulated by a meteorologist, Edward Lorentz, around 1960s, had built a weather model and. - Sorry, a meteorologist came up with chaos theory? - Yeah. - Okay. I didn't know.
Is weather and meteorology is that, that's classical chaos theory, that has nothing to do with quantum. - Chaos is basically a property of classical dynamical systems, not just physics, like any kind of dynamical systems you want to predict. Like for example, the population of fish in a pond or weather is another example. And then even in stock market or something like that, chaos has applications in every, so many fields actually.
So dynamical system is basically any system that evolves with time. - Sorry, you said a, a dynamical system. - Dynamical system. It's any system that evolves with time. And so you basically have either differential equations, like you have a set of variables, for example, for whether you can have variables as temperature, pressure or something like that. And differential equations telling us how those evolve with time basically.
So now these differential equations, if they are nonlinear, if they nonlinearly depend on the other variables, then it results in. - Maybe I'll, I'll just ask a question to make sure I'm understanding. You're saying that, you know, weather can be an example. So is this why I might sometimes look at my phone and see that it's supposed to rain tomorrow, but then it doesn't actually rain.
Is that, is that because it's very difficult to predict, is that related to the fact that it's a chaotic system? - The weather is a chaotic system. That's right. So the thing is like, we all know that we can't really predict the weather of any place. Like for example, if we look at the weather of Waterloo today, how is it going to be tomorrow or day after? And we see that many times, it's not the same as what it is tomorrow, right? So why is that the case?
We have advanced technologically so much, but still we can't really predict the weather a few days in advance of any place. If we had predicted, like if we could have predicted so many catastrophes and on earth would have been, could have been like avoided, or not avoided, the destruction could have been avoided. - Yeah, if you knew a hurricane was coming a month in advance, rather than a few days. - Yeah. - In advance, you'd be. - Something like that. - You'd be grateful for chaos theory.
(laughs) - But the thing is they are predicted only a few days in advance with some probability that this could happen. So it is because like these models are nonlinear, so they can't be solved exactly. And they can exhibit chaos that whatever initial condition we input, for example, the temperature or pressure, whatever we input in, in the bunch of, for the variables in the bunch of differential equations, those variables will have some error in the last visit.
Like if we have five visit (mumbles) in our value of the temperature, there is a small error in the fifth visit after the decimal, right? So that very small error in the last visit actually can amplify upon evolution of the system. - Right. - The more precise we are in the initial value. - String of digits after the decimal. - Yeah. - Is.
- The longer we can actually predict the weather to the likelihood of the weather in advance, but it will lead to unpredictability after some time, no matter how much precision you're given, there is going to be some error in the end and that will lead to unpredictability in the long term. So that's why weather is an unpredictable system. But that's the thing. Weather is a very complex model and it may look like chaos is a property of very complex models, but that's not true.
Even very, very simple systems, for example, double pendulum, is chaotic. So double pendulum is basically like you have some simple pendulum in which you have a bob attached to like some knob, which oscillates in a plane. Now you attach one more bob to the end of the first bob. - So I have kind of a, a stick or something with a ball on the end. And then I have another. - Yeah. - Rod attached to that with another ball on the end. - Yeah. - And it can swing independently of the first, right?
The first ball can swing, would not independently but affected by. - They will be dependent in some way, but overall the motion is chaotic actually like you can search various YouTube videos actually that. - They're really fun to watch by the way, double pendulums. - Yeah. - Good hypnotic entertainment. - Very small initial condition change can lead to high unpredictability actually.
So that's the thing, that chaos is not just a property of complex systems, but very, very simple systems can exhibit chaos. - Interesting. - So I, I wanna ask something here just to make sure I understand. So you're saying with weather, if I'm say measuring the temperature, it might be, say 20 degrees Celsius, but I'm not sure if it's 20 degrees or 20.0001 degree Celsius. This seems like a very small change.
And if it was a non chaotic system, maybe the result two days later wouldn't depend so much on whether it was 20 degrees Celsius or 20.0001. But because it's such a complicated system that's non-linear and we call it chaotic, it's in the end gonna depend a lot on that really small difference in that variable. Is that correct? - Yeah, that's right. So that small difference in nonlinear systems put in principle amplify to very large differences in an unpredictable manner.
But if it is a linear system or if it is an integrable or regular system, like different words for the same time, then those small differences won't amplify a lot actually, or it'll amplify a very predictable manner. - I see. - If it'll amplify, like there can be unstable boundary systems in ways, things can amplify, but we still know how it amplifies. So. - So, may I jump in? A quantum system, is that more complex or less complex than weather?
Quantum being very small and, and there's parameters around it. What does quantum chaos refer to? - Quantum chaos has not been very well understood yet. Although it's been like a hundred years of the development of quantum theory and why is quantum chaos and quantum classical correspondence is an important problem. I'll like to give another example. For example, Galilean relativity was well known from a few centuries, right?
And then came in a special theory of relativity where the speed of the object can be very, very high. Now, as you start reducing the speed of the object towards normal speed, special theory of relativity, very smoothly merges into Galilean theory of relativity. It's not like Galilean theory of relativity is wrong, right? It is still right at the level we observe our everyday world. Then this new theory of, this new theory of relativity was formed. - By Einstein is? - Yeah. - Okay.
- That's right. - I got that one right. (laughs) - And then it smoothly merged with the old theory where the old theory was predicting things very well in normal circumstances, which we can observe through our eyes. Likewise, classical physics is very, can't very well predict our everyday world that we see around most of the things. And then quantum theory is something that describes phenomena.
The microscopic level are at levels, which is, does not happen in normal or circumstance in for example, very low temperatures, chem temperatures near zero Kelvin or something like that. We don't really see that. So for example, super conductivity. So you can see defective super conductivity at a macroscopic level. It's a big object visible to our eyes, right. And we see that, but we can't ex-- - A levitating super magnetic train or something like that. - Yeah, that's right.
So, so that happens at very, very small temperatures, although it is macroscopic, but quantum mechanics is the thing that predicts it where a thing is there, there has to be something different from normal circumstance where classical physics fails, for example, very, very low temperature or very, or microscopic scale in terms of like size of an object or something like that.
So quantum theory explains the microscopic world or the world or other circumstances where things are very different from what we observe in day to day like temperature or something like that. And then classical physics explains our everyday world. So in principle, quantum theory should merge as we scale up the size of the object or as we'll scale up the temperature or something like that of the system. Quantum theory should very smoothly merge into classical physics.
And we should be able to understand that convergence because classical physics is not wrong. At least, we know that, know that most of the things around us is spread is, could be predicted using classical physics. This is the field of quantum classical correspondence and it is more or less, fairly understood for integrable or regular systems, but for chaotic systems, it is not still understood. - Why is that?
Is it just because it's a extremely difficult subject that's difficult to measure, you're dealing with tiny microscopic-- - So there are fundamental differences how in the formulation of quantum mechanics and classical physics, actually.
In classical physics, we've see chaos through trajectories actually in phase space, like phase space is something like you take the position and momentum of a particle and then track how the position and momentum evolves and it will curve out a trajectory in the phase space. - And what's a trajectory? Just kind of the path that it follows. - Yeah, that's right. But not just position, you have to add, there is another axis, which is momentum.
So in general, when we see a particle, it's just position, right. But there is a momentum associated to the particle, which is for normal particles. It is mass times velocity. So that is another axis. So the phase base is formulated by position plus momentum. So classically it is possible to measure the position and momentum of particles precisely. And the chaos occurs in the finest structures of the phase base carved through these trajectories actually.
But quantum mechanically, due to Heisenberg's uncertainty principle, we can't have precise values of position and momentum at the same time. So we don't have trajectories in quantum mechanics just like the way we have it in classical physics. So this is one of the fundamental reasons we can't pick up the definition of chaos in classical physics and use it in quantum physics actually.
So just because quantum physics is formulated in a very different manner than in classical physics, understanding chaos in quantum physics, the same way as it is done in classical physics is not possible. But as I talked about earlier, there should be a smooth convergence of quantum physics into classical physics as we scale up the, the size of the object or things like that.
And in quantum mechanics, the superposition and entanglement are two purely quantum properties, not there in the classical world. And entanglement is like, if you have a, we were talking about quantum coins. So if you have a couple of quantum coins, if the coin is classical, you both, if both can be in heads or both can be in tails, or one can be head and one can be tail. But quantum mechanically, you can have a state like a superposition of head, head, plus tail tail, something like that.
And when you measure one of the coin, if the pair of quantum coin is in this state that I talked about, head head plus tail tail, then if you measure one coin and if it comes out to be heads, the other coin is bound to give heads when you measure it. Likewise, if the first coin comes out to be tail, when you measure it, the other coin is bound to be in tail. - And this is even if the two coins are far away from each other. - Yeah, this. - Held by, handled by separate people.
Is this, this is what Einstein said was spooky action. - Yeah, that's right. - Where it's where it seems like one thing far away is happening at the very same time is as, as a different thing. I know that's probably not the scientific explanation, but that's, is it fair to say that that's one of the things that we just don't experience in our everyday lives? - Yeah, that's right. - So we have a hard time wrapping our heads around it? - Yeah, that's right.
So that's the thing that if you prepare these two quantum coins and suppose you give one of them to Alice, other of them to Bob, and if they are prepared in this joint quantum state, entangled quantum state and Alice suppose goes, goes to Australia and Bob lives here in Canada, and then Bob measures his quantum coin. And if he gets heads and then instantly Alice will observe if she makes a measurement on it, on her coin, that it is in head actually.
Likewise, if Bob gets tails, then Alice will see to be tail. So that's the thing like. - That is spooky. - That is spooky. And that's the thing that we have observe. This is called non-local correlation because it's not like a measurement in Canada is affecting something in Australia and instantly. So, and we know that information can at most travel with the speed of light. It can't travel beyond that. So how does this happen? So that's why it is called non-local correlation.
The thing is like, this is very surprising that this happens, but it is found to be true in several experiments, actually. So, and it is still a question like, how does this happen? How do we understand actually, that this happens. It is very, very surprising in that way. - It seems like there are a number of mysteries that need to be solved.
And you've mentioned sort of the big, a big one of, at what point does the quantum world sort of move into the classical world that we inhabit and why is it so hard to sort of pin that down that, that making general relativity and quantum mechanics play nicely together? Because that seems to be the focus of a lot of work is understanding the, the change between quantum and classical. - So these are two different questions actually. - Okay, well then, yeah, I can rephrase that.
I guess I'm getting at this question of understanding where quantum ends and where classical begins and, and why there's not sort of a total agreement there. Why is it so challenging to find this, I guess unified theory? - Quantum classical correspondence, that's a correspondence that's why is an active area of research actually like, and we don't have an answer to that, I guess why.
- Maybe my follow up question is then it's for decades, people have been working on this challenge and it's a big challenge. Is it not daunting as a scientist to take on challenges that are so unsolved for so many years? - So it is unsolved for so many years, but it's not like no progress have been made. Like there have been so many different kinds of properties that we see.
Like we can classify systems, whether they're using classical mechanics, whether they're integrable or not, or chaotic or not, depending on like, whether it, whether the system has a classical analog. So there are several quantum properties that people have come up with in these studies where they see that they behave differently when the classical analog is integrable or chaotic. But all of these properties, what we have found is there is some exception and physics is a study.
Physics is a, is a like, field where most of the innovations happen when we see an exception, actually like if we had thought of what the photoelectric effect, as an exception, study it separately, that it doesn't follow the rule of classical physics. We wouldn't have this third theory of quantum mechanics now, right? So whenever you see an exception, that is the area of growth. So like, so many advances have happened, but we still do not have a single answer.
And there is a possibility that after a few more years or after a couple of decades or something, there are so many pieces of this puzzles that people have found. There will be someone who can glue all of them together and find an answer. - Might it be you? - Hopefully. - Is that a hope that, a sort of professional goal that over your career, you will move this field forward a certain amount?
- I mean, I started my research with that goal actually, and I have made small progress in some of the questions or the conflicting answers. And I hope that that is the big goal, actually, that I hope someday if I can answer how quantum classical correspondence happens in chaotic systems. Like that is a big goal. - Yeah. - I hope someday. If possible, me, that's fine. Like otherwise someone answers that question.
- And so why did you choose to come here to the Perimeter Institute to kind of help make progress towards entering that question? - Perimeter Institute is a place where like there's so many, it's a theoretical physics place and being a theoretical physicist, like a perfect place. And then other thing is like, there are so many different areas of research here and people like so freely collaborate with other people in other areas. And these intersections are most interesting actually.
Like I started my PhD, I wanted to work in quantum chaos, but then my advisor had worked in quantum information. So she gave me like this problem of understanding quantum chaos through this quantum information perspective, actually. And then I got into the field of quantum information and then here, like we have different fields. Like I have collaborations with other postdocs and quantum, quantum foundations and condensed matter.
So those intersections are really interesting finding people from other areas. And it's a very active place in the sense that there are so many visitors from all around the world, actually like giving talks on so many different topics. So using techniques and tools from one branch to other branch, that's where I think sometimes major innovations happen.
For example, like quantum, quantum information is one thing that has led to like the tools and techniques in quantum information has been used from condensed matter to high energy physics, actually, like black holes also, you have this black hole information paradox or something. And in condensed matter, you have these questions about thermalization, (mumbles), and where tools and techniques from quantum information have been used to answer some of the questions.
So these intersections are really interesting and that happen a lot at parameters. So I'm really excited to be here and collaborate with other people. - Yeah. - That's fantastic. I was just, I wanted to ask a little bit further back in your past. Were you always, since you were a little kid, interested in quantum physics? How did you find this career path? - It started in my high school that I became, became fascinated with physics. I think in my primary school, I was more interested in maths.
I think I had an analytical mind and always took a, a delight in like solving problems, difficult problems actually, like. - I read that you would solve problems, logic problems from a magazine. - Yeah, that's right. - Yeah, just on your own, just for fun? - Yeah, it was mostly for fun. I had elder siblings who were preparing for general competitive exams in which there were maths and logical questions actually. And it was a fun to see whether I could solve them in my school. So that happened.
And then in my high school, preparing for a national level engineering entrance exam. And in that, in that exam, basically problems that were there were very complex. Like it was not just formula based that you are given a problem and you have these variables and this is the formula, you plug in the variable values and you get the answer. That is not the kind of questions, like it. You had to think from first principles actually to, to solve those complex problem.
So I was preparing for that exam and I had joined a coaching class, which was very usual back in India. - Coaching for this particular exam, like tutoring, to learn how to take the exam? - High school students, one thing is you have to give school exams like board exams. And then another thing is you have to get into a college or university after that. So these national and level entrance exam, these coaching classes, they taught things at a more fundamental level.
Like board exams was slightly simpler in the sense that as I said, you can have variables and plug in a formula line and you will get answer, but to crack these entrance exams, you really needed to think for, from first principal.
So the teacher, like my physics teacher in my high school, in my coaching class played a very, very big role, I would say, where I became fascinated with physics because he taught us how to think from first principles, like given a problem, which seemed very complex in the first place. And I would be like, there's no way I can solve it. And then when you start with these first principles, just like the very basic equation, which is, I think it was to Newton, Newton's second law.
If you understood this equation well, there was so many types of problems that you can solve, very complex problems. And just seeing that, that everything combines together in this simple equation and you can solve difficult problems, seemingly unsolvable in the first place, that gave me another level of delight, I suppose. And I enjoyed this and the way my teacher taught, I really imagined myself like, I felt like I wish I could develop some of these equations or something like that.
That was so fundamental using, which you can explain so much, so many phenomena in the world. So that really made me think that I wish, I mean, pursue this research career in the first place. - And where did you go from there? You went to undergraduate studies. - Yeah, so I cracked that engineering exam, national level. - Yes, you told us, I believe, of the 400,000 people that took that exam, you're in the top, what, one, 2%. - Two top 2%.
- So you weren't gonna mention that on your own, 'cause you were being too humble, but she, she aced the exam, then what happened? - Yeah, so I was able to crack that exam and then I went to an engineering institute and I was there for a year, but somehow I didn't feel quite at place there. Like, and I didn't, couldn't picture myself becoming a researcher after studying there. I don't know why. I just didn't feel like it. I still tried to understand why that happened.
And at the age of like 18 or something like that, deciding to put a place like that and go to a new college was a risky decision, not supported by many, but I was not feeling at home at that place. And then I wrote an exam for another institute, undergrad institute, which was more research focused. I qualified that exam. So I went ahead joining the other institute where I did a bachelor's degree in physics.
- And I really wanna ask something here because for those who might not know, I know Meenu, you wrote such a really nice article as part of this story, "What is it like to be a woman in physics," which is a collection of stories by women here at Perimeter Institute. And I just wrote down one of my favorite quotes.
You said, it was not normal for a small town girl from a conservative society like me to leave home for undergraduate studies, let alone later travel to a foreign country for graduate studies. And the rest of your story is really great too. And I just was wondering if you can kind of speak to that piece a little bit. What was it like to make that decision to challenge those societal norms? - I was very scared in my school time actually.
Like I was seeing most of the women around struggling actually. Like I have a bunch of like very strong-headed women around in my back in my family, or extended family, but I still see that trying to break any social norm. Like they have to put so much effort. And after putting in so much effort, little by little, it breaks them down somewhere actually. And that hard life that I was seeing, all of them living, I felt like I really need to have a better life, which I can live on my own terms.
It was not normal for families back in those days actually to send their girl, girl child to study outside of the hometown, actually. It was not considered safe or something. It's norm, it's relatively normal now. But at, in those times it was not that normal. If I could crack this prestigious exam called ITJ, it was very prestigious and it would be a prestige for the family. They will be willing to send me if I can crack this exam.
So I put in a lot of hard work and effort and I was very, very scared. What if I couldn't crack it? Like I will be stuck here. But with hard work, I think hard, hard work and conviction, I was able to crack that exam and leave home. So it was slightly difficult. - And home, home is a relatively, I think it's Gaia and India, Gaia. - Yeah. - It's, it's more of a tourist place. I think it's a spiritual destination because there's connections to Buddhism.
- Yes, that's right. - It's probably not a place where a young girl says I wanna be a physicist and gets the warmest reception. What kept you going when there, you said you, you met opposition at stages along your way? - First of all, I really liked studying and solving analytical problems in physics and math. That was one thing. And the other thing was like that conviction that I want a better life.
So both of those things like, and the third thing, like I really got amazing teachers like these coaching classes I am telling about, like I had three different teachers who were extremely supportive, always there. Taking classes from them really, really helped. And they were there to answer my questions or support me in any way they can.
So their presence meant a lot at that time, actually their belief in me that I can do something, I can crack this exam, even though it is difficult, that really helped. Due to those factors, I was able to make it.
- And moving, you know, from a small hometown to another city, let alone a country on the other side of the world, that was a big, was that moving to Canada to do grad, to do a PhD, was that a, a difficult leap for you to make or was that always in the cards that you would go somewhere to, somewhere else to become a researcher? - I don't exactly remember when was the first time I really thought that I could go to a different country and live by myself and study on my own.
That was, that was not something that I thought from the beginning, but then in my college, like I was the third batch, there were two more senior batches than me and I was seeing other students, including women, going out to other countries for research projects, summer internships or for graduate studies. And I just felt like if they could do it, I'll, I'll be also able to do it. So I followed their footsteps in that way. So, yeah.
- And you created your own footsteps too, you know, for others to follow. - Yeah, hopefully it will inspire others as well. - It's interesting, right. I think for so many people it's so important to have those role models, right? Whether they be your colleagues that are a year ahead of you or somebody that's maybe already a professional in the field. Was it important to you to have role models at maybe different levels along the way? - Yeah. So my first role model I would say is Kalpana Chawla.
Unfortunately she is no more. So Kalpana Chawla, she was the first Indian woman to go to moon, actually during her second trip to moon, there was a crash in that shuttle and unfortunately they all passed away. So yeah, she was a big role model for me. Like she came from a small town in another state in India, which is Punjab, and seeing her like reading her story, knowing about her. I felt like if I followed her footsteps, I could do something as big as her. So that was really important.
Looking back, I, I can never think that I could have looked up to Neil, Neil Armstrong for example, and thought that I could have done something similar or something like that. But having someone who has same gender, same ethnicity, same back family background, like similar kind of family background. And you can dream big if you see some other people with similar situation dreaming big and being able to make it.
So in my childhood, I always dreamed off becoming an astronaut, just like Kalpana Chawla, changed over time. But I think her presence and whatever she achieved in her life, knowing that helped me dream big, at least in my life. - Yeah, that's amazing. - Amazing. - Would you, if someone offered you a chance to go to space, now that space tourism is a thing, would you wanna be an astronaut still? - I think I'm less of a tourist and more of a person from research.
Like if it was more of an opportunity to go there from a research point of view, I think I would be more interested rather than just going there and seeing things, how it looks like. - If you did have to now say what's your dream, what would it be? Would it be to crack this quantum classical correspondence? - If I could play good enough role in tracking that question, that would be really nice.
But apart from that, like all these innovations happening in quantum computing, I keep on thinking to the day, like, it, sometimes it seems like it is a big dream, which may or may not happen. But then I keep on thinking that about the time when classical computers were devised, like the first computer were like the size of a big room. And now it's like in our hand. - Yeah.
And actually at the Institute for Quantum Computing where you were, some of the quantum computers, there are the size of a room. It's, it's a, it's a similar analogy there. - Yeah. - Quantum computing is sort of at that infancy stage, but you can see the, the potential and you got to work right in the, in the middle of a quantum computing research center.
- Yes, that's right. - Well, I, I love the way you put it earlier, too, that sometimes doing research involves putting together so many little pieces of a puzzle, right. And you have these pieces. It's not always obvious how they fit together and it's not always obvious how many pieces there are, how long it's gonna take to put them together. But I think even figuring out how to glue together two pieces is, is a big accomplishment in many cases, right.
- Yeah. - I'm curious to know if you still have that same joy that you felt when you were a kid solving puzzles. If doing math and solving difficult problems, is it still fun? Is it still like a hobby for you the way it was as a child? - Yeah, like whenever I get any new idea, I'm very excited to try it out, whether it'll work or not. That's the most exciting part of my research projects.
Like, and these ideas just happen to come around like while I'm doing some stuff, which doesn't require a lot of attention, for example, washing dishes or cooking or something like that, or, or waiting at the bus stop for the bus. So these are the moments when some ideas will just come to my mind and then I'm so excited to try it out, whether that will work or not. And that is the most joyous part of being a researcher for me.
- Interesting, even if it doesn't work out, even if the idea falls flat and doesn't pan out? - So as long as a few ideas are working out out of many, like as long as two or two ideas are working out out of 10, suppose, that's fine. It will be a little frustrating if I thought of 10 ideas and nothing worked out. (laughs) But luckily, if I think of 10 ideas, two to three ideas turn out to work so. - Trial and error only works when there's some error. So yeah, you need to. - Yeah.
- Well, Meenu, we now wanna take some questions if that's okay. So we, you know, as part of this, we wanna see what other people wanna ask you as well. And so we have a question today that was actually sent in by a student from our PSI program here at Perimeter Institute. So for those that might not know, PSI is a one year master's program in theoretical physics here at Perimeter Institute. I actually teach in that program. I teach lectures in quantum science and machine learning.
So we have a question here that's from one of our students named Anna Kinur. - What does it mean to do research through the lens of quantum information? Do you really think the world can be reduced to only information? - First of all, thanks a lot, Anna, for that question. That's a great question. So the thing is in my research, since I started my PhD, I started working on quantum chaos through the lens of quantum information. So that has been a majority of my part in my research.
So I can't really speak of a general term, in general terms, what it means to research and from other perspectives, a lot. The thing is quantum information, I see it as something that has brought together different fields in physics, like it has provided a new perspective in different fields. For example, in condensed matter to high energy physics, which look like distinct topics, actually in the first place.
Like if you go back like 30, 40 years ago, all those physicists, you can classify them as condensed matter physicist or high energy physicist. But now that's not the case. For example, I would talk about a faculty here at Perimeter, Beni. Like he works at so much, like he is, he is very much into high. - Beni Yoshida? - Yeah. - We know Beni. - Jinx. - Yeah, so he works very much into high energy physics, like black holes stuff, as well as condensed matter physics.
And he is a faculty in the quantum information research group, looking at things from the point of information perspective gives us more pieces of the puzzle, the bigger puzzle of physics actually. And it definitely helps. And maybe it'll be piece that solves bigger problems in physics, who knows. - So it's not necessarily about answering every possible question, but giving a new way to look at or a new perspective. Yeah, oh, cool. - To the existing problems, other fields of physics actually.
So it's definitely an interesting way. I have been working in it for seven years now since the start of my PhD and I have really enjoyed it. - I have a question from someone named Ahmed, a student here in Waterloo region, and he asks why can't quantum mechanics agree with relativity? - Thanks, Ahmed for that question. So thing is generally a theory of relativity, space time is continuum.
Energy is also continuous, but in quantum mechanics, space time is at equal footing in general related theory of relativity and energy is a continuous thing. But in quantum mechanics, at least in the starting, if we talk about the starting or picture, space and time are at different footing, plus energy is discreet. It is quantized. And other thing is like, we still do not have a quantized period of gravity.
Like those pieces are required such that we can glue together general relativity and quantum physics. - Is that quantum gravity that's-- - That's the bigger umbrella, yeah. In which people are trying to figure out how to quantize gravity so that we will be able to glue together these two fields. - So there's a whole field of research devoted to answering that question, I guess, yeah. - Many faculties here, I guess working in that area.
- Well Meenu, you've been so generous with your time and it's been really fascinating chatting with you. Thank you for joining us. It's been great. - Yeah, thank you. This has been just so much fun. I've really enjoyed learning more about you, even though I've known you for years, I've learned so much about you. So thank you so much for sharing your time with us. - Thanks a lot, Lauren and Colin, for having me. (upbeat music) - Thanks for stepping inside the Perimeter.
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