Hello and welcome to this series on physics and philosophy from the University of Oxford.
I am Ankita Anirban and in the series I'm trying to explore some of the fundamental questions we ask about the world.
What is the nature of space and time? Can something be in two places at the same time?
Is this the only world that is, or are the parallel ones just like this one?
And perhaps most fundamentally of all, what makes us human?
I speak to a number of physicists and philosophers who are addressing these very questions
and their research today and who embody the intrinsic link between physics and philosophy.
Physics is not just about prediction, it is about understanding.
And as Dr. Christopher Palmer says, a true understanding in physics can be greatly enriched by an appreciation of philosophy.
When you learn physics in school, you pick up a lot of fundamental physical ideas like mass and force position and acceleration and so on,
which you take on board as something that you can use and put into equations and do calculations
with without necessarily thinking carefully enough about the meaning of these terms.
And a philosophical reflection shows that all of these things are actually quite a lot more interesting.
And in some sense, theory laden than the initial engagement of the school pupil would lead you to suppose.
And it's actually quite interesting, too, to look back on the things that you've learned from a more philosophically informed perspective,
to understand things that you, in a sense, already knew but haven't really noticed about the theories that you're using.
And that process of informing your physics from a philosophical perspective can
be very fruitful and lead to new lines of inquiry at the research frontier.
Or at least that's my hope.
Dr. David Wallace explains the importance of using physics and philosophy to complement each other and answering the big questions.
At least as I think about philosophy, it's less a particular subject matter, it's more a way of addressing problems.
And in particular, I think it's a way of addressing situations which are conceptually confused or tangled.
I think by and large, when any given bit of philosophy has become sufficiently untangled that it's completely clear what the questions are,
then we largely stop calling it philosophy and start calling it something else.
20 years ago, maths was part of philosophy. 400 years ago physics was part of philosophy.
100 years ago psychology was part of philosophy and so on.
And I think what that brings to the study of other subjects is that the philosopher isn't so much saying,
Here's my specific philosophical knowledge that I can apply.
He's moving here in my way of asking certain questions, exploring the structure of things,
understanding what the arguments being used are and how they fit together and when they don't fit together.
Now, in the case of physics, physics has gone through various phases and different bits of physics have gone through
them at different times where the subject is more or less calculated with nature.
So physicists are very successful in taking.
Sometimes a relatively poorly understood conceptual speaking area of the subject.
I'm trying to do tend to push as far as it goes, trying to generate new results, trying to make ideas, the tests and so forth.
And then she that works very well as a method as long as the subject is quite experimentally connected.
Because if you've made a mistake in the way you think about it, you can always be brought up short by the fact that you fail some experimental test.
But there are various places in physics where just understanding how to do the calculation isn't enough either
because we don't know how to do it or we haven't got the experimental check or because we do know how to do it.
But we still want to understand what's going on at the deeper level.
Since the idea of physics isn't just prediction is understanding. And there I think philosophical techniques can help to disentangle some of
the the confusions that can be going on in how different ideas fit together.
And I think in different ways in theory of space and time,
the theory of statistical mechanics and thermal physics and perhaps above all, in quantum mechanics,
if you have philosophers who are sufficiently serious about the physics and sufficiently humble to learn how the physics works,
then philosophical ideas can really help us out there.
Today, physics and philosophy seem to be disparate disciplines, often taught and studied separately and in isolation from each other.
Yet as the scientist begins to delve into the foundations of physics,
it seems that metaphysics is required to gain a deeper understanding of the subject.
Similarly, the matter physicist needs the knowledge of modern science to develop philosophical ideas that are relevant to what we know today.
Professor Frank Gonzalez tells me about his experiences with physics and philosophy.
So I started out studying physics, and like many people that started to study physics,
I basically studied physics because I had read some popular books by people like Feynman and Einstein,
and those tend to be about the foundations of physics rather than anything particularly applied.
And that was what I was interested in. But then as I was studying it, I had discovered that as I went on in third or fourth year,
I was interested in asking questions that physicists were telling me, Oh, no, no, these things we're not interested in.
You should go to a philosophy department to study those. I thought that was a little bit strange because it was, after all, foundations of physics.
But I thought, okay, so I went to a philosophy department and in the philosophy department, this was in Holland.
They weren't studying foundations of physics, they were studying German and continental philosophy.
So I thought, Well, that's really strange. This is not helping me at all.
So that I moved to England, where ultimately I studied in a philosophy department, foundations of physics.
So intent on my view about what the relation is between philosophy and physics for the thing that I'm particularly interested in,
foundations of physics is that it's just a historical accident, that foundations of physics is studied in philosophy departments.
But I think for the general public, if you want to explain what I'm doing, it's much closer to physics than it is to philosophy.
I also thought for a long time that you could study philosophy of physics.
You have to have to do it in a philosophy department. You didn't really need to know any philosophy.
I thought, No. You just need to be thinking clearly about the foundations of physics with all these stuff
that philosophers study and philosophy department is by and large completely irrelevant.
It's just a historical accident that we're doing it here.
However, I think about 15 years ago or so I came to a philosophy department where there were some really good physicians,
and it it's only then that I became convinced that some philosophical education and thinking
about certain philosophical issues very deeply does actually affect your philosophy of physics.
So the relation between the two is, roughly speaking,
that philosophy becomes important when you want to do foundations of physics properly and simultaneously.
I believe that a lot of metaphysician pyramid physicians who don't know any physics or are interested in the fundamental structure of reality
are completely crazy if they think that they can say things interesting about the fundamental structure of reality without doing physics.
So the ideas for at least a certain part of philosophy, namely metaphysics, physics, is absolutely fundamental.
And for a particular part of physics, namely foundations of physics, philosophy is absolutely fundamental.
This series explores a number of questions that require the strands of physics and
philosophy to be brought together in order to gain a better understanding of the world.
First, I speak to Dr. Christopher Popper about the historical links between physics and
philosophy from the ancient Greeks to the pioneering scientists of the 20th century.
Next, I explore the ongoing debate about the structure of space and time.
Professor Frank Antonius.
Professor Vlatko Vedral then explains some of the unexpected and mind boggling results that quantum mechanics provides us with.
These include ideas about parallel worlds, which are discussed with Dr. David Wallace.
Finally, I look towards ourselves and I speak to Professor Roger Penrose about consciousness,
the mind, and how far science can take us towards understanding our own nature.
I don't quite know whether I considered to be a philosopher or not.
I'm interested in deeper questions, of course, but whether they're questions of physics or philosophy or sometimes mathematics, I don't know.
I mean, I would like to call them philosophers just with the philosophers, except what I think or not.
I mean, to me,
it's just an extension of science because we there are some deep questions which are scientific questions such as what's the nature of consciousness,
what's the nature of emotions and things that we think of.
It's not exactly to do with physics that which nevertheless have to do with us.
And we are parts of the physical world. And so these questions are things that you might think of as philosophy questions.
I hope that you enjoy listening.