welcome to the science for the public lecture series science for the public is an organization committed to bringing science information and issues to the general public this is our website for our program this time we discuss how scientists in this field really unravel the mysteries of the universe in addition to her academic position as a theoretical astrophysicist at yale dr natarajan also holds the sophie and tycho brahe professorship of the dark cosmologist center at the niels bohr institute in the university of copenhagen denmark she also holds an honorary professorship for life at the university of delhi india and dr natura john is also an elected fellow of the american physical society her list of distinctions is very long so we refer you to her website or to tonight's event page on our website for more information the focus of dr notter johns research is in dark matter maps of the galaxy clusters among other major concerns of astrophysics but she is also very committed communicating science to the general public this commitment is reflected in her articles in new york review of books and most especially in her splendid book mapping the heavens the radical scientific ideas that reveals the cosmos we are delighted for the opportunity to talk to dr knot or john about how she and other scientists actually make their discoveries and about the importance of public science literacy today were field resolves these big mysteries probably some of the biggest and so i wonder if you could tell us something about a few knowns in astrophysics and then maybe a few let's go ahead so i think one of the exciting things about all science and of course about astrophysics as well is that we are constantly pushing the boundary between what is known and what is known and that's really what research is all about trying to sort of enlarge the domain of what we understand reliably with evidence with data so for example in cosmology at the moment we one of the one of the things that we understand extremely well about the universe is the life cycle of stars we know how stars form we know how they evolve and age and how they die and we know as a function of the initial mass of a star how massive it is it is to start how it would evolve so all these tracks so that physics is extremely well understood for example right however there are lots of concepts that are not as well understood and one particular example is the you know the idea of dark matter and the idea of dark matter today is very much unlike sort of the invisible fluids and invisible entities of the past like even ether that your way and the reason that this is a different concept this is here to stay although we don't know a lot about dark matter we do know that the bulk of the matter in the universe is made up of this dark matter which does not emit absorb or reflect light but it has mass it's some exotic particle that formed in the early universe we don't know which particle it is we have some candidates we haven't found it however because dark matter has mass and it exerts gravity you detailed maps of dark matter even though we don't know what the dark matter is so the sort of this i think it illustrates very very nicely this sort of boundary between what is new and so aspects are extremely well known and it incontrovertibly evidence i would say i mean there's some skeptics within the community who are trying to look for alternative theories i mean this is part of science nothing successful yet as a viable alternative but you know we're constantly pushing the boundary now is obviously to try and find and pin down the particle and either pin it down a bunch of different ways pin it down by directly detecting it using either the large hadron collider in sun or directed to action experiments that have been devised sort of focused on the expectations of the kind of particle that we think constitutes a dark matter so so far we had been fixated on this particle called the neutral lino but you know we've come up empty so far looking for this particle that another viable candidate is the x e on and till very recently we believe that the axioms were possibly a little too light to really be to account for all the dark matter plus for us to detect but it turns out we've had a new breakthrough at the moment and the been a recent recalculation and it's possible to have a slightly heavier but slightly different properties so you know you can expand our search space now so the other way to finding sort of dark matter is sort of in direct ways from astrophysics like the sort of work that i do which is coming added by looking at sort of more collective phenomena sort of looking at you know aggregates of dark matter particles how they behave and then try to sort of zoom in on what kinds of candidates might be permitted or not so i think this sort of illustrates you know the case of dark matter really brings into sharper focus the fact that there is this ever moving boundary between known and unknown and the project speculative where this itself is so originally maybe it was treated almost as a bizarre idea originally but increasingly there's less and less doubt about it it's a question idea that was proposed was actually came completely from empirical data and so there was a need for some kind of unseen matter that would basically hold up galaxies and account for the gravitational influence they have on the motions of stars in them and so on the concept of the multiverse is slightly different it's a theoretical idea and its origin comes from the fact that you know in order to describe almost all the properties of our universe you just need a handful of numbers which can be measured and we have measurements for our universe for those numbers and they have very specific values and the question is if these values were even slightly different we would not end up with the universe that we have we wouldn't be here to ask those questions and so on so the idea is who are a lot more interesting lee what determines what those values are or those parameters of defining parameters and easy way out i don't i don't i'm not saying that it's a cop out but an easy appestat miku way i want is to say that you have these six numbers they have distributions of potential values and you know various combinations of six are realised actualized in different universes so there's a multiplicity of universes out there we just happen to be living in one which has the values that we measure and so potentially you could have an infinite number of universes it is a speculative idea and at the moment we haven't quite figured out how to test the idea i mean there are some interesting potential lines of inquiry like you know maybe you could have some kind of remnant from early collisions of into bubble universes that are part of this infinite multiverse and maybe there would be some kind of imprint on our universe perhaps in the cosmic microwave background radiation which is sort of the relic radiation from the big bang something like that you know i sort of comfort myself when i think about this you know in fifteen forty three copernicus stright shifted the pivot from the to the sun for our solar system right he could have never even imagined that human beings that we would have been able to launch two satellites the boy just wanted to that could actually leave the entire solar system at his time in fifteen forty three sort of system was the cause we didn't really know about anything system now so you know i don't know what future one can predict the future so might reveal to us i remain very optimistic that you know we might actually find a way to empirically test the idea of multi versus  i don't know when but i have no doubt that you know we potentially could but it's a very good point that it's known well we don't have a way to prove or disprove at this moment another one that for the sort of the fiery sort of fireball beginning of the universe that the universe started from a very hot dense compact state that is extremely well established by any many independent lines of  that are details that we still could understand better but i think the sequence of events is extremely well so you've made tremendous progress in actually confirming things that were had to be speculative because you didn't have an for very long time and now you have more like degrees of certainty in some areas and you're clear about where things are speculative for the time being but with technology improving yes so much so fast and so on i would that were doing really well like to talk about a wonderful article that you wrote in the new york review of books it's one of my favorite all time articles period as you reviewed several books in that one and the thing that i found most interesting was one dealt with curiosity one dealt with ignorance these are books and one dealt with the blunders that scientific scientists make and these people are very prominent scientists and writers in any case you made a very big point of something the of science could you please tell us through that yeah so i think that was my first essay for the new york review of books and i have a tremendous amount of fun writing it so i think the main point that i really wanted to put across in that essay was the fact that there are features there are fundamental features of science which actually give vitality to the subject which are essential to the nature of science and the scientific enterprise and these concepts are the ones that drive scientists to do their work however these are the very concepts that make it very difficult for the public at large to understand science to comprehend it and also to really get a fe ality that what we know today is the best to date knowledge best to date understanding and that when we get better data more data more sophisticated instruments to make better measurements then our understanding is going to get honed and it is going to change so scientists are actually very excited at this prospect of change and evolution and i think the public finds it a little disorienting because the pace of scientific discovery is so high it's really the pace is so fast today that you know it's very hard to keep track of what's going on and it's hard not to feel sort of disoriented by the process  by sort of the new discoveries that are sort of coming apace so i think there's the provision ality of science is one concept and then hand in hand with that is the idea of uncertainty the fact that you know measurements have a fundamental uncertainty that comes from the limitations of the instruments that we have to make them and they also come from a limit the limitation comes also from our understanding at a given point so once our understanding improves the data improve we have a much better view much better theoretical grasp of the concept and and this is how science really progresses and that you know these are i think facets of science that are particularly exciting for scientists and as part of our training we we are taught to stay open minded and so it really at the bottom of this even we resist new ideas when there was a proposed yeah and particularly if they're somewhat radical you know if they're not they're radical in a real departure from whatever is a conventional thinking at that moment so even scientists push back but you know eventually scientists partly because they're training and partly because they are open minded and the data really evidence really dictates how we change our mind we're forced to change our mind in terms of  scientists enjoy this on their own and surprises and everything else but and you're trained for it to a certain extent but it seems to be a mentality to begin with curiosity that kind of insatiable and flexible for the most part it is really critical that we in the public become more like this have a more open mind but for centuries the traditions have ruled us so whatever the tradition of our particular cultures of the religion sort of the politics or whatever that's handed down and it's very firm and it's very do you think we can overcome this that through the public i mean i think that you know there is no reason that even someone who is not trained as a scientist cannot be flexible open minded and nimble in how they think and i think you're absolutely spot on when you said that part of that has to be an acknowledgment and respect given to curiosity and wonderment and questioning the fact that you know you have to be open to not just asking questions but also be allowed to are yes and want to ask them and want to challenge them that is a sort of very active engagement with ideas at all times i think that part of the sort of institutional sort of top down handing down of ideas is the underlying that is the notion that some things cannot be questioned yeah and you cannot engage with them so that's a very passive stunts of dealing with the world we can no longer have that the wildest changing really fast we're changing it yeah  and i think therefore we have to be able to be opening up open to challenging what's going on and thinking critically yes and asking the growing questions about what's going on so that we can understand so actually there is a biologist john mello who i think has has a nice very base idea it's called civic scientific literacy and he talks about this concept of how to live in a democracy the citizenry have to be aware yes they have to be questioning they have to be engaged yet so that they can actually participate much more effectively as citizens in the country in th around the globe but also in their personal spheres when they take decisions you take a decision about you know medical treatments that you have to take you know if there's a chance of there's a probability that if you go through radiation therapy then the cancer that you have has you know a certain probability of being gotten rid of you have to be able to make those judgments and i think we live in a complex and of society now that we all have to make these judgments all the time and so being better equipped with the means with the mentality and the means so the mentality to be curious and ask questions and the mentality to be actively engaged i think you need the combination of both and this sort of scientific temperament is what it was classically called i think it's much needed in today's world much more broadly as you bring up a very good point there that you really in a sense you cannot separate the civic literacy now that we actually cannot function and i evil anywhere in the world without science and right and if we're going to save the world we most certainly used to have this attitude and it's curious you know children have that curiosity it somehow gets drummed out of us it seems like but it's cheering to think that you know if scientists may maybe it will be contagious but we need a different thing and you know i'm the sort of element of surprise yes you know being the ability to be surprised that you actually have to be open to being surprised exact and science because a lot of the discoveries have a surrender purchase element to them yes that once again you know we are open and trained to accept serendipity when we encounter it in terms of your own work you obviously have a very broad mind and so on but you must have come up against some real challenges in your spectacular discoveries could you tell us like give us an example of your own experience with this unknown yeah so i think that my own experience sort of one of the interesting intellectual challenges for me has really been about the practice of science about how science is now done science now especially in my field is done in large collaboration's in groups and so that you know because the field is mature and part of belonging to collaboration is there's an element of doing science by consensus and i actually want to be able to take creative risks that kind of lists only an individual can take or a small group of people working together on a speculative idea can take and so for me the conflict if you will through my career so far has been you know there's a part of me that wants to be you know included in this sort of big and just and to prize big science and then there's the other part of me which is really the more sort of true part of me the authentic part of me that wants to work on my own not entirely solitarily but in smaller groups i think the tension for me has been the desire to push to do speculative stuff not unknown and the unknown and to synthesize and use ideas that you you know have learnt in some other sphere are going to reapply them sort of to new questions or to have the freedom to do all of that so i think for me that has been a bit of a because it's big science needs big money and that's really model yeah that's really where a lot of the funding goes and individual researchers and small groups are not as well funded you know in the last decade or so i'm hoping that you know it'll change coming in right if we have the public awareness i think that would change that need to be publicly funded people need to understand that you must fund long term some of it speculative research and so on but there's plenty of money it's just going in the wrong directions you know it's being wasted but thank you for sharing that with us i guess that might be i don't know a common attitude among theoretical people that people started out there were very unpopular with these ideas riginal a over and over in your field certainly where many of those ideas were not just unknowns but right well looked like they were off the wall you know originally so that it is changing but thank you for bringing out that we all need to adjust our mentality here and that if we did it will be much more exciting anyway i have one more thing to interesting dot org and you have done work with this and you are cited by them could you tell us about that one of the things well i've asked you yeah and i think you know john brockman is an incredibly interesting mind he you could call him sort of an evangelist for science and for a sort of a new kind of science a more integrative approach to science combining science and arts and you know there was a sort of this infamous sort of  false dichotomy sort of between science and the humanities science and the arts attribute it to see peace know the two cultures i think john brockman started this new third culture believes that you can actually unif and i am in complete agreement with him because i think that there is no way that you can actually separate out these ideas into can parse big ideas into science and arts and humanities i think these disciplinary boundaries  quite artificial and they actually prevent us from making leaps in progress and so it's a wonderful organisation where he invites people who are thinking and working on a whole whole bunch of different fields scientists humanists and he provides them this interesting platform it's a very it's a nice long interview about why they do what they do how they do and invariably listening to anyone you know any one of those you would immediately see that these sort of artificial disciplinary boundaries really don't hold the you know excited intellectual curious intellectual minds behind it all i mean they really don't kind of believe in these boundaries are you know transcend these boundaries in how we work in how we think and who we are and i should mention that you write poetry and you are very comfortable in the arts and i see this constantly with people in science they don't see these barriers and these have been artificially imposed as you say a kind of tribalism and artificial tribal as possibly you know an artifact of you know academic departments the anniversary and now we're organizing  intellectual work yes and i think that you know i think those boundaries are going to dissolve and yeah i'm and it's definitely true that a lot of the most exciting cutting edge work today is happening at the boundaries very interesting very interesting that people intersections of those boundaries what is just before we leave what is like your current project of the current so the current exciting project that i just finished a couple of papers in my research group is on so one of the problems i work on is the origin of the first black holes in the yes that's right and so the traditional idea was that the first black holes the seeds that you would get would be from the end state of the first stars that form in your owners they would burn up all their fluid they would burn up all their fuel and then leave behind a little remnant black hole and that would be the seed from which all the super massive black holes that we see today in the centers of most galaxies including our own that's how they would have originated but the idea that you know this this may not be the only way to make the first black holes was something that we came up with about ten years ago and that was driven by the fact that growing black hole imagined earlier so then that brings us to a bit of a timing crunch so you form the first stars you have the little remnant black holes and then you're immediately seeing very soon after five hundred million years or so after the big bang you are seeing these black holes are about a billion times the mass of the sun that are glowing because of the gas that's falling into them as quasars that we're detecting and we're starting to see a population of them so if you need to grow a seed from ten times the mass of the sun to a billion times we have very little time and so we came up with this idea of direct collapse black holes so these are black holes that are much more massive from the get go when they form so this is a black hole that forms that's about ten thousand one hundred thousand times the mass of the sun and it forms bypassing the formation of a star so you have a gas you know the early universe you have this gas disk that gets unstable and phenomenon with and you accumulate matter very quickly to the center and you would form this direct lapse black hole so the interesting thing of course is how would we know when you look at a black hole later on for example we look at the black hole at the center of the milky way which is about you know a million times four million times the mass of the sun you cannot tell how this light hole for i write so there's no memory of how the black hole actually what went into  race at all and that's a feature of black holes that we don't actually know how they are what all went into forming the black hole so what we discovered though is that these direct collapse black holes go through a very interesting stage in the early universe they form and then they rapidly muds with another with a galaxy that has formed stars instead of forming a dry clubs black hole and there is a stage when the mass of the black hole and the growth of the black hole will out all the stars and so it will be they will be very very bright objects but in the early universe they'd be very dusty so you would see them not in the optical or the x ray the x ray penetrates through dust but this is a huge amount of so where you would see them is in the infrared when you would have the radiation that sort of absorbed and reradiated in the infrared so this is sort of long wavelength low energy and so the james webb space telescope that is going to be in two years actually has the best detectors i see in the infrared the near infrared the mid infrared and the far infrared so we just predicted the spectral signatures the fingerprints of these objects and we discovered that james webb space telescope should see them if they're there they're boring they were right and for a while and so they should be detected if they are there and you know if we are right and this model is right they should be detected so that's what's the most exciting thing i either going to be validated or not and it's exciting either way right we all will learn something either way but it's also revolutionary in terms of the thinking of black holes at the beginning so you will you'll be getting a nobel prize i'm so glad you came to see us before then i don't either but i just mean friend i mean i think for me what is really exciting is to be doing science right now where you know the first sort of proposals for this idea we put forth in two thousand  that i feel very fortunate and lucky to be here and to be able to do what i'm doing i still can't believe i'm paid to do this so the field is very fortunate to have you too and thank you ever so much and you really given us thank you an