Professor Michelle Simmons AO
Boyer Lectures 2023
Centre: Professor Michelle Simmons with students at the Australian Research Council’s Centre for Quantum Computation and Communication Technology (CQC2T).
Lecture may vary on delivery.
04 THE IMPORTANCE OF DOUBT
When I was made Australian of the Year in 2018, I wasn’t at all prepared for what followed. Stepping from the ceremony into the glare of the media spotlight, was like nothing I’d ever experienced. I found the cameras confronting. I was embarrassed to be on show. I couldn’t get my head around the need to communicate in small bites. And I was completely perplexed by some of the questions I was asked: “Do you believe in God?” “Should Australia be a republic?” “What’s your take on Australia Day?” “Do you find it easier to talk to your children about quantum physics or sex?” Being a physicist is not an ideal background for this sort of thing. We’re trained to analyse physical systems, not to influence human ones.
That’s as it should be too. When I hire someone onto my research team or into my company, I don’t ask myself, “Could this person stand in front of 500 people and inspire them?” No. I want to know if they can work in ultra-high vacuum, if they can write control code for a scanning tunnelling microscope, and if they can perform a high frequency, RF measurement. I want hard skills. And when I study a problem on my own account, my starting point is never what I need to say or do to convince people I’m right. It’s to wonder about what we can measure and quantify, what variables we can control systematically, and whether I can trust my own beliefs. I want truth not rhetoric.
The world is rather different from this. Indeed, my impression is that the world at present has quite a complicated relationship with the truth – and you don’t need to have had your 15 minutes of fame to appreciate this. There are philosophers who’ve taught that truth is relative. The media has convinced us that truth is just a narrative. One hears phrases like “Well, that’s just your truth” as if truth is just a matter of personal preference, when it obviously isn’t – although you can always disagree with someone about what you both think the truth is likely to be.
All of this troubles me. Physics simply cannot proceed without the idea of the truth. I’m not sure a society can really function properly without it either. But I’m also not sure what’s to be done about it because, as a physicist, while I value truth intensely … I also equally value doubt.
This may seem a strange thing to say. Most people associate physics with certainty and the wider human tapestry with doubt. Yet, in my experience, people don’t like doubt one bit, whereas physics is heavily dependent upon it. I long ago learned the vital importance of doubt for scientific discovery and technological progress. And during my year as Australian of the Year, in and out of the media spotlight, where people seemed to expect such certainty (and self-certainty), I gained an appreciation of how little room there is now left in our society for doubt – even less room, arguably, than there is for truth!
It is sometimes said that, if there is a crisis of truth in our society, the only way to fix it is through education. I’m not so sure about that either. A good education does teach truth, but our knowledge will always be imperfect. And it’s hard to be taught a truth without it also hardening you. We’re all prone to our dogmas, which is why the educated mind is, in some ways, a caged mind. To be open to new truths – to be willing to change one’s mind when you realise that something you once thought was true is actually false – you always need room for doubt. This is why I believe the difference between a good education and a great education is not truth … but doubt.
A good education serves three purposes. First, it imparts knowledge. It explains what others have already discovered, shines light on reality as we currently understand it and helps us to make sense of our world. And although the best knowledge is universal, the effect is always personal. Because what you know shapes who you are and what you’re capable of. You can’t be a quantum physicist without a certain amount of mathematics. Our knowledge is the bedrock from which we launch our lives.
Second, a good education teaches skills – ideally skills that are useful, for the benefit of students and their society. When I hire staff into my research group or my company, one of the more obvious things I look for is skill: not just what a candidate knows, but also what they can do, what they would bring to our venture. And if a candidate doesn’t have the specific skills we need, I look to see what other skills they’ve learned – coding, maths, touch typing, design, public speaking, statistics, critical thinking, the ability to communicate complicated concepts, a sporting prowess, or the ability to play a musical instrument. Because a demonstrated capacity to learn and develop skill is itself a useful skill.
Third, a good education also instils social standards or what might be termed ‘positive conformity’. By this, I mean it instructs people on how to behave. This is one of the under appreciated benefits of attending school: you acquire the habits of institutional life, conscientiousness and the manners necessary to get on with others. When this is done well – i.e. when it’s constructive not stifling – it gives you an understanding of how to succeed in the world that is just as important as anything else you might pick up in the classroom.
But is this enough? A great education gives much more than knowledge, skills, or good habits. At a more fundamental level, it teaches you to take responsibility for your own truth. I love that phrase. It’s a line from one of history’s greatest physicists, Richard Feynman. (Those of you who listened to my last lecture may remember him.) But it might equally have been spoken by Socrates or Martin Luther. All three of these men argued, in different ways and at different times, that individuals should take responsibility for their own understanding of the world. All realised that truth is not something to be received, or taught, but something to be discovered; and something for which everyone has a unique, personal responsibility.
The problem is that to discover truth you must be prepared to doubt and to question authority. That’s hard; and it’s getting harder. Some of you may know that the motto of the Royal Society in London is ‘Nullius in verba’ – ‘take nobody’s word for it’. This is the ethos we try to put into practice every day in my laboratory, but it’s not an easy thing to live by. Nowadays, the world is full of people who possess an absolute certainty in their own opinions. Political positions and value judgements are increasingly laid out as incontrovertible truths. And the social pressure to think the same way as everyone else is more intense than I can ever remember.
Partly, I suspect the heightening of this phenomenon has been driven by social media, which is rendering our public conversations increasingly shrill and concerned less with truth, and more about being seen to be right. For me, social media is much like a pipeline of intellectual destruction that converts little fragments of knowledge into perceptions of absolute certainty – and doing so as effortlessly as water flowing down a drain.
But this is not the whole story. There has been a movement across society, and in educational circles, that is more interested in the promotion of self-esteem and empowerment than in the measurement of competence or the discovery of knowledge. As a consequence, I sometimes wonder whether we live in a time and place where we are not allowed to have doubts anymore. And I struggle deeply with that, because as a woman, and as a person who had a pretty ordinary education growing up, and above all as a physicist, I am a professional doubter.
Doubt is essential for physics. It is the seed from which the whole discipline grows. Think about this for a moment. Those who feel certain about things tend not to question them. Why should they? On the other hand, those who are doubtful are often deeply compelled to question things. Doubt does a much better job than certainty in stimulating our curiosity, which is the great well-spring of science – indeed of all truth-seeking.
This is one reason I think it is so important for adults to spend time with children – especially young children. We all know that kids tend to have curious and open minds. My suspicion is that this is because they’ve not yet become seduced with too great a certainty in their own knowledge.
Self-doubt can also make us rigorous. To be successful in physics, especially in experimental physics, you’ve got to expect the worst. Disasters happen and details matter. Being thorough is absolutely vital. Reality is a hard taskmaster. You simply can’t rely on luck.
But what drives someone to take the trouble of being systematic? To test and re-test their equipment? To question the meaning of their data, over and over again, even when they think they know what it says? And what keeps someone in check, so they can almost instinctively avoid jumping to conclusions?
Many things are important in all this: good training, a fierce work ethic, attention to detail, patience, technical proficiency, and the desire to discover the truth. But self-doubt fuels all of these things as well. It is a motivator for training, for working harder, for paying closer attention. Which is why I say, so long as it doesn’t demoralise anyone to the point where they give up, doubt is essential – for scientists and for society.
Personally, I learned this the hard way. In my family, growing up, there was a strong expectation that the women would look after the men. Each week I had to do the ironing for my father and brother. I grew up in a culture that did not necessarily promote self-confidence in its women. I also went to a rough school in South London where learning was something of a miracle for any of us. Boy George was our most distinguished alumnus, although he was expelled for wearing a bin-liner instead of his uniform. To give you a sense of the place, in my year of about 200-300 students, only 16 did their A-levels (the equivalent of our higher school certificate), and only two of us passed.
By the time I made it to university, self-doubt was part of who I was, so much so that, when I arrived, I went to see my lecturer just to check there hadn’t been some mistake in my admission, and that I really belonged there. Then later, at Cambridge as a postdoctoral fellow, I came up against a perception that women couldn’t do physics. This was a view openly (and at times discourteously) expressed by male colleagues.
Today, as education expands from its traditional aims in the diffusion of knowledge … to encompass new goals relating to empowerment and the promotion of self-esteem, my past experiences would be regarded as woefully inadequate. Yet I rarely feel that way. Indeed, in one important respect, I feel lucky, because being the recipient of such a chaotic education taught me to question myself constantly – to doubt my own knowledge and my own beliefs. And although I haven’t always valued this, I appreciate it now because being able to doubt, freely and without reservation, is a gift. I only wish more people felt the same way – especially women, who are so often advised to hide their doubts.
In my world of quantum physics, as most people know, there are very few women, less than 5%. Many people have speculated about why this should be so, but no one really knows the answer. It’s a situation that persists despite a widespread and desperate contemporary desire, amongst both male and female physicists, to change it. So, I don’t believe it can be explained simply as a function of male prejudice, although I may be wrong.
Intriguingly, I’ve observed, in my own students and colleagues, certain differences in the way men and women learn and think. These aren’t differences in ability, but differences in inclination, interest, and especially in confidence. Above all, I’d say that women in general are more likely to doubt themselves than men are. Whether that’s cultural or just the way we are, who knows. I don’t think it matters either way. What does matter is that an excess of self-doubt can be very discouraging for young women choosing which subjects to study. What usually happens in these circumstances is that we conclude that self-doubt must be a liability … and that we should do everything in our power to foster confidence. We try to find ways – some direct and some more surreptitious – to convince the women not to doubt themselves. We show them role models. We try to pump up their self-assurance.
I know from personal experience just how this feels. I had an uncle, now sadly deceased, my Uncle Tony, who lived in America for many years. When I was a teenager and he sensed that I was doubting myself, he would tell me to say to myself in front of a mirror: “Hot damn I’m good! Hot damn I’m good!” It never worked; although, to a shy English girl, using such a brash American phrase at least had the benefit of making me laugh, and humour does always help put things in perspective.
The fact is, though, that emotions are not so easily manipulated – especially those tied in with self-perception. There is no magic wand that can be waved, no incantation to recite, that will dispel self-doubt; and always there’s the potential for an unexpected feedback loop. The fundamental issue is that as soon as we signal to someone that they ought to have less self-doubt, we also reinforce its undesirability and their own failing for feeling that way in the first place. Could this be why so many of our targeted efforts to encourage women to study physics have failed? And why such efforts have not always been good for men either?
In New South Wales, for a long time, we had a physics curriculum that was supposedly tailored to make girls more confident with the subject. It didn’t work, and the education department in that state has returned to a more traditional curriculum. However, in the meantime, a generation of students came through my laboratory with a weaker grounding in the discipline than they should’ve had.
What I say now to young women who are looking for inspiration is it’s probably a mistake to try to lose something so valuable as your self-doubt. Indeed, what I would say to aspiring physicists (both male and female) is that self-doubt is not a liability, it’s an asset; that you need to figure out how to control it; but that you should value it and channel it because it will make you a better scientist. It will probably even make you a better human.
Just ask yourself this: Is it more important to be seen to be right or actually to be right? Is it better to win an argument or to know what the real truth is? Is it more useful to be considered good at something or actually to be good at it? And how much do you really know for certain? And just because someone – or indeed everyone – says something, does that make it true?
Those who strive at the limits of human knowledge, venture out into the unknown based on what is already known.
In my laboratory, I’ve had some of the greatest experimental researchers in the world working with me – all incredibly well educated and expert people. Our success builds upon literally millennia of prior knowledge. Our single-atom transistor came half a century after the invention of the original transistor. It came more than 100 years after the discovery of the electron, and thousands of years after Democrates first conceived of the idea of atoms. Looked at retrospectively, we are experts, adding to a vast chain of learning. Every new discovery extends our accumulated knowledge. Looking to the future, though, one gains the opposite impression, for there is so much still that we don’t know and may never know. The way I see things, we’re still just scratching around the edges of vast reaches of human uncertainty.
One of the hardest truths to face is that we’re all fundamentally ignorant. And, strangely, this applies no matter how well educated you are – indeed it may be harder to appreciate the better educated you are. A person who tops the state at the end of year 12, or wins a university medal for their degree, or completes a PhD, may well have bucket-loads of ability, dedication and talent, but they haven’t even scratched the surface of what can be known.
The most educated and learned people may know a lot about certain things, but their knowledge is just a drop in the ocean of what it’s possible to learn. I, myself, may be a professor of physics and a specialist in experimental quantum physics, but the number of questions I cannot answer, even in my own field, is infinite.
That is just part of being human. Yet, because knowledge is so important – and valuable – most people see their ignorance as a weakness, as something to cover up and hide. So, there is a tendency to bluster, to pretend to know when we don’t, and we can achieve this by affecting agreement with the majority, or with whoever seems to have the most authority or the loudest voice.
The problem here is obvious. It turns us into mere parrots of other people’s ideas. It encourages us to rely on authority figures, who may be wrong, and to be satisfied with repeating whatever the group thinks, which also may be wrong. It undermines critical thought. It dissuades people from speaking – or even seeking – the truth.
This is the exact opposite of taking responsibility. There are times I’ve seen even this creep into my own research field, in physics, where the pursuit of truth is part of the job description. When nobody wants to be wrong, and everyone wants to fit in, groupthink takes hold. And when this happens, it always stands in the way of honest understanding.
In science, we have checks to try to prevent this from happening: peer reviews, systematic approaches to experimentation, an insistence on proof and empirical observation. And yet it still happens.
Unfortunately, doubt of any kind is not easy to teach. Indeed, all the components of a good education mitigate it. When you are the recipient of knowledge, when you’ve had skills bestowed upon you, and you’ve been shown how to fit in, it is very hard not to desire certainty and a fixed belief in all you have learned. As compensation for this, I wouldn’t wish upon anyone the kind of wayward schooling I received, but it does raise the question: how can you preserve your doubts – that most valuable quality – even as you become educated or expert in your chosen profession?
I don’t know that I have an answer to that question, but based on personal experience I can make some recommendations:
Admit uncertainty. In my field of research – in the quantum world – there is uncertainty everywhere, but the same is true of life. The things we don’t know often matter just as much as the things we do. And the person who seems to know everything is frequently the first to lead everyone else astray. Even as you learn … you should make a virtue out of uncertainty.
Practice humility. Our society is too firmly fixated on pumping up confidence and inflating self-worth. But humility is essential. Even the smartest and most self-righteous among us are ultimately limited in what they know. No matter who you are, you can’t be right all the time. Nor should you have to be. Sometimes the best thing you can to say is, “I don’t know.”
Above all, take responsibility. Ask yourself, will you contribute more to the world if you believe what everyone else says, or if you take the trouble to work out your own views? This is a message for young people especially. Exercise your curiosity muscle. You should be prepared to ask your own questions and find your own answers, and to recognise that your education ultimately depends on you.
There are times I wish more people would be willing to take some of these ideas on board. If you understand what I’ve set out, perhaps in future you will no longer be satisfied just to accept knowledge as it’s given to you; but will actively search for knowledge on your own account. You may see that a true education is something that lives well beyond the confines of any institution. You won’t want to acquire skills just so you can serve someone else’s ends; you will master skills as a foundation for your own pathway in life. And while you may accept conformity of manner, you won’t succumb to conformity of thought … but will think for yourself.
Only once you’ve become a true friend to doubt … will you start to properly take responsibility for the truth.
There is a very famous photograph, taken in 1927, at a conference in Brussels, Belgium, to commemorate the fifth Solvay Conference on Physics. At this meeting, 29 physicists were brought together to discuss the emerging theory of quantum physics. Of this group, an astonishing 17 had either won or would go on to win Nobel Prizes.