Can philosophy of science have an impact on physics? | Sabine Hossenfelder

[Music] sabine hostenfelder welcome to how the light gets in nice to meet you um so can said this famous quote the two things filled his mind with all in admiration the story happens above him and the moral law within him do you have a feeling of or an admiration towards the universe sometimes sometimes more so sometimes less so depending on what news page i look at uh i mean there's certainly a reason i went into science because that's what inspires me um so certainly that plays into my motivation to go on with my research and is it is it hard to revisit that sort of feeling of oh and kind of mystery many years down the road when you're when you're a researcher and you're caught in the thick of it it's kind of interesting how much my interests have changed over the time like when i started out doing physics like 20 years ago i was very much into particle physics you know i thought that's the most interesting thing ever like what's metamate of what are the smallest things and how does everything hold together you know how does the whole universe get built up of these tiny things and i i've drifted away from this towards more you could say philosophical questions about how much can we actually really understand using mathematics about the origin of the universe about also the structure of matter but also what we mean by a measurement you know can we take the human out of the equation uh that kind of thing yeah absolutely and in relation to that i mean you've long argued against sort of looking for beauty in physics and how mathematics can somehow lead physics astray down sort of rabbit holes um even if there isn't a place for beauty and physics is there still a place for creativity you think is physics a creative endeavor yeah you're phrasing this a little bit more strongly than i intended it to be it's not that i say there's no place for beauty and physics what i object to is that a lot of physicists in particular theory development use very constraining notions of beauty and they just assume that nature has to fulfill them and what the argument that i make in my book lost in math how beauty leads physics astray is that if you start with the assumption that nature has to be beautiful in a particular way for which you have a mathematical expression and you use this as an assumption for your theory development that's the wrong way to go about it instead we should be looking at nature with an open mind and i think that's how we will find new beauty so it's not like there's no beauty but i i don't like it that physicists use beauty in this very narrow sense so you're asking is there a place for creativity and science well it's pretty much impossible to do science without creativity um but it's it's kind of a very constrained type of creativity uh compared to the arts where you have a lot of freedom whereas in science it's very technical to some extent you know there are lots of rules you have to obey and you can't just say well i'll break them a little bit right you're not allowed to do this and then theoretical physics in particular a lot of those rules are just mathematics um you you you just you can't just say well i'll forget about the mathematics and um stop believing in it so apart from sort of this this notion of beauty physics is also driven by other values and a kind of key one is simplicity right theoretical physics for a very long time has been trying to get a unified theory of everything having one simple sort of model that explains everything do you think that's also a sort of wrong motivation to be looking for simplicity and singularity in physics or is it actually helping drive physics innovation so there are actually two different notions of simplicity one of which is just i would say a natural ingredient of science which is that you should make a theory more complicated than it has to be and so if you have some kind of theory doesn't really matter what it is you shouldn't add unnecessary assumptions um and that's really really important i think to some extent physicists themselves don't really understand how important this is because if you don't have this assumption you cannot you can always do something like saying and god made it right and that would be a justified assumption but the reason we throw it out is that you don't need it um to actually make a prediction with the theory and so this is what you could call occam's razor don't make any unnecessary assumptions but there's a different kind of simplicity that especially in the foundations of physics scientists often refer to which is what you just said we're looking for a theory that's just simple period and that's certainly driven to some extent by looking at the history of physics where we have seen a turn towards simplification you know we had this uh periodic table you know with all these different elements and then we explained them by way of quantum mechanics that explains all these energy levels in the properties of the elements and then we discovered the atomic nucleus and the constituents of the nucleus and those constituents were themselves made of other things and we ended up with this fairly simple theory which is called the standard model of particle physics where we have like 25 particles that makes up the entire universe i still find this stunning so that's certainly simple but it could be simpler and that's certainly driven a lot of research in physics and at this point you have to ask like does it really have to be simpler like does there have to be something simpler than this and i think we just don't know so i don't think it's a good assumption to start from that the next better theory that we find necessarily has to be simpler so going back to philosophy that you mentioned earlier your your interest drifting in that direction and thinking about where the human is place in all this concepts like measurement and the subjectivity that we bring with it do you think science will be able to accommodate those eventually accommodate human subjectivity and the human kind of perspective of the world or is that always going to be something that's left for philosophers to discuss well i would say it's more something for sociologists to discuss but it's kind of it's quite funny actually i think that a lot of what counts as philosophy is actually more sociology of science so those two are closer related than i think philosophers would like them to be so i've been very interested in figuring out how much we can possibly learn about the origin of the universe and it's when you speak to people who work on this they seem to vastly overestimate how far we can go with the scientific method and then we have in the in the foundations of physics and quantum mechanics we have this issue with the measurement problem and there's been like a hundred years debate over whether or not we need to understand the role of the observer in it and also it may it leads to the question like what do we mean by an observer to begin with and i think these are super important questions that physicists kind of prefer to not acknowledge which makes things easier but it also means that you may be making a big mistake without even noticing so do you think that philosophy can philosophy of science and philosophers that think about these kind of the questions left untackled by by science can that discussion influence how science develops or is philosophy always just sort of describing and kind of theorizing about what science already is doing do you think do you think philosophy of science can have an impact on on physics and how it develops it can whether it will i don't know it's certainly the case that a lot of physicists are kind of not very friendly with philosophers they tend to find pretty much everything that comes out of philosophy useless i don't share this opinion but it's certainly something that i observe among my colleagues and i have to say to some extent it's justified because a lot of what comes out of philosophy actually isn't particularly useful and a lot of it is just looking at what scientists do and then trying to make sense of it and i think they that philosophers should be a little bit more proactive you know they should actually go and say this isn't okay and this won't lead anywhere and we've made this mistake before and you should have learned from it but you shouldn't but you didn't um so i think there's a bigger role for philosophers to be played in the foundations of physics yeah i think what you're saying is particularly true when it comes to something like the philosophy of time like i can see many philosophers who just sort of take the findings of theoretical physics about time and then try and figure out what they mean rather than kind of challenge them and very much very quickly are happy to concede that time is an illusion where it doesn't really exist or things like that is that the sort of thing that you have in mind for philosophers to kind of challenge some of the results that are coming out of physics so that happened to be a topic that i'm not personally very familiar with um but yeah i guess it's part of the reason is of course that a lot of the philosophers don't really have the necessary background to actually question what comes out of physics so they kind of take what comes out of physics and then they're trying to make sense of it uh and it's it's it's a similar thing when you look at particle physics like what i wrote about in my book like this this notion of naturalness um it's not that they're so much critically examining it uh so they're more taking what comes out of physics and then that they're trying uh to make sense of it um but i also know a lot of physicists who went into philosophy or a lot of philosophers who have some kind of degree in physics and they do really great work like for example i think in cosmology this is becoming really really important where we have david merritt he recently so he's a an astrophysicist turned philosopher and he's re recently written a book with the somewhat off-putting title a philosophical approach to bond but it's a really thorough analysis of dark the dark matter hypothesis versus modified uh newtonian dynamics and he's asking like which of those two theories actually does better explaining evidence and he rates these theories on the scale um on criteria that have been provided by uh philosophers and and i think that's super useful now we only have to get the astrophysicist to actually read it and how has philosophy influenced your work as a physicist has it made you ask different kinds of questions than you would have had otherwise does it impact the kind of research that you think you're interested in doing how does it what's the impact of having studied and read and thought about philosophy in your work as a physicist yeah it certainly influenced me i think most prominently with the realization that you have to be very very careful about how you define your terms and you have to be very careful about stating which assumptions you make but also so as i already said i've been drifting more towards philosophy because that's kind of where all the questions end in the end and so it's naturally gotten me interested in how much can we possibly know um where does our knowledge end which is something that philosophers have written about uh for a long time and uh are there some recent big shifts in cosmology that you're excited about is science uh the science of physics kind of moving forward or has it is are we going through a kind of more stagnant period how do you see the moment that we're in well cosmology is an interesting topic to mention because i actually do see that there's some things being shaken up you know where people were once very very sure they have it all figured out and now they have a lot of new data whether like you know it doesn't really fit in you know maybe we'll have to think about this again and one of those cases is for example the cosmological principle which roughly speaking says that the universe should be on on the average the same everywhere like if you average over very large distance scale the distribution of matter should roughly be the same and it it just turns out from observations it's not the case and that's a problem because that's one of the assumptions that underlies the current standard model of cosmology which is also called the concordance model or lambda cdm so it's all the same thing and that's very interesting because if you don't have the cosmological principle you basically have to redo all these data fits and that can shake up a lot of things and it could resolve some tensions and maybe lead to some new discoveries you're a big science communicator you have your own very successful youtube channel um you didn't start that way you started as a blogger a science blogger what's the difference between the written word and the visual kind of representation that you've found and and you know which of the two do you think is a better medium for communicating science ideas to the public oh well i i think they're they're both good but some work better for some people uh somewhat better for other people it just seems to be the case naturally i would say that a lot of people find it easier to follow explanations if there's actually a person speaking like a real human being and they have some audio signal basically also i mean a nice thing about doing videos is that you can add animations and graphics that's just much much easier than if you only have the written word and you have to find these clumsy explanations for things with metaphors that never quite work um so there's definitely a benefit to switching over to something visual it also has a disadvantage because there are many more things that you have to pay attention to basically you know if you just write you write and then you're done with it whereas if you make a video not only do you have to think about the the scientific content you also have to think about how do i get it get it across um how do i speak clearly how are these english words pronounced so it just brings up a whole bunch of new problems and what are you currently working on what's a project that you're currently passionate about research-wise i'm working on modified gravity dark matter which i've been working on for some while so we have some papers in the pipe that will hopefully come out by the end of the year i'm also working on the measurement problem in quantum mechanics so this is where my philosophical interests have taken me it's something i kind of do on the side and i just finished writing a book so i'll have a new book coming out next year in the summer which is basically it's about the intersection between philosophy and the foundations of physics so all the big questions also about the nature of time is time and illusion does the past still exist does the universe think all these kind of things are in my new book what is what do you think is the biggest kind of question that arises from physics that has a kind of big philosophical question behind it well it depends on you know do you mean the question the biggest question for me or the biggest question for the average person you would meet on this street i think what most people care about very very deeply is free will has physics ruled out free will and my book has a chapter on that so personally i'm much more fascinated by this question like does the future already exist which seems to be strongly suggested at least by einstein's theories of space and time belonging together and what do you think that means do you think we can actually change the way we sort of live our day-to-day lives if we come to that realization that time is an illusion time is the future is fixed it's all laid out like a map and we're just navigating it in some ways or is this always going to be just an intellectual exercise for us it depends very strongly on what you mean by change so arguably as we live our life we have to make decisions and you could say those decisions make a change in your life for example so that's one notion of change you can talk about and that's perfectly compatible with the deterministic time evolution now if you're asking had there actually been different possible futures and did i get to choose one of them that just isn't compatible with the laws of nature that we uh currently have okay so i've been hustling filter thank you very much for more debates talks and interviews subscribe today to the institute of art and ideas at iai tv

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Keywords: learning, education, debate, lecture, IAItv, institute of art and ideas, IAI, science without the gobbledygook, quantum mechanics, quantum physics, lost in math, particle physics, sabine hossenfelder, sabine hossenfelder free will, theoretical physics, gravitational waves, scientific method, general relativity, sabine hossenfelder interview, theoretical physicist interview, can philosophy of science have an impact on physics, physics and philosophy, philosophy of science and physics

Id: S3UNPOG3ZJ4

Length: 17min 55sec (1075 seconds)

Published: Tue Apr 05 2022