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hello everyone and Welcome to our Dark Matter day Q&A I'm Caitlyn bjo and I'm a firm laab science Communicator um and I'm host for today's live stream uh today our physicist will be answering some of your questions about Dark Matter to submit a question all you need to do is type hash ask forab in your question in the chat today we're in one of the Dark Matter Labs at firy lab the CCD testing project lab we wanted to bring you into to one of the spaces at fmab where physics is happening but in case you hear some background noise that's the sound of science now let's meet our physicists today I'm here with fmab dark matter physicist Dan Baxter alexer licker Wagner and Anna bti can you each
introduce yourselves your research focus and what projects or experiments you work on we'll start with Dan gladly so I'm Dr Daniel Baxter I'm an associate scientist here at the lab and a joint associate professor at the at Northwestern University um I from training I am a dark matter physicist which is why I'm here I think and I've worked on a number of different types of experiments including with uh charge couple devices or ccds uh Xenon time projection Chambers and bubble Chambers but most of my work these days actually focuses on Quantum Computing and superc conducting cubits which includes the question of whether extremely sensitive quantum computers might be able to look for dark matter okay and Alex go ahead
and introduce yourself hi I'm Alex derag I'm a scientist here at fmy laab and an associate professor at the University of Chicago I'm an experimental cosmologist I work with telescopes and cameras to observe our universe I'm very interested in the distribution of Dark Matter within the universe as well as what it could be fundamentally composed of some of the projects that I work on are the dark energy survey the dcam local volume exploration survey and the Ruben Observatory Legacy survey of space and time all right and Anna hi there uh I'm annati I am a research associate here with perula my background originally is in astrophysics and Cosmic race and nowadays I work on Direct deture of that matter particularly in
the Sensei andura collaborations that we are trying to find for like that matter and I mostly focus on developing the technology and developing the detectors to measure these very rare particles awesome great having you all here today so let's get some of the basics out of the way Dan can you tell us what dark matter is gladly so dark matter is the classification that we give to what is basically missing matter in the universe so everything that is around us this chair myself the camera is all made out of standard model particles like protons neutrons and electrons dark matter is something else okay so it sounds like there's maybe an abundance of dark matter or unknown matter hanging out in the universe
Anna can you tackle how do we know Dark Matter even exists so basically the way we see that matter and the strongest evidence we have for that matter is through gravity we see in the universe how the galaxies move we see how the structures Sur it and we see a lot of other different phenomenon related to the Pres of that matter that we see through gravity but yet I mean if that matter is matter as that was saying should be some kind of particle and we haven't had any direct measurement of these particles yet okay so dark matter is abundant in the universe and we can't see it that sounds like our favorite ghostly particles neutrinos Alex are neutrinos Dark Matter yeah that's a great question so early on
in the study of dark matter it was thought that neutrinos could possibly be the Dark Matter however from observations that we've made of the universe we found over time that neutrinos are just too light and moving too fast in the early Universe uh to make up the dark matter that we see there so while neutrinos are an interesting candidate and there may thetically be some new currently unknown species of nutrino which we call a sterile nutrino that could make up some of the dark matter the neutrinos that we study in the lab today are not okay so even though neutrinos are pretty ghostly sounds like they're not spooky enough to be dark matter so Dan can you answer for us why dark matter is called Dark Matter gladly so the name is actually
very specific uh the word dark comes from the fact that when we observe the universe whatever dark matter is not interacting with light for this reason we can't directly observe it in our telescopes we observe its interaction gravitationally on things that do interact with light which is how we know it exists the matter part of the name comes from the fact that it does interact gravitationally which means it has mass dark doesn't interact with light matter has mass Darkness matter it's a very specific name actually awesome okay Alex um one our next question is what's the relationship between dark matter and galaxies so dark matter is actually the backbone the Skeleton on which uh the galaxies that we see in the universe form so to the extent that we're able to
study them galaxies appear to form in larger clumps clusters of dark matter without that dark matter there the uh gravitational force from the normal matter alone wouldn't be enough to cause the formation of galaxies at the periods and to the extent that we see in the universe today so every uh Galaxy is essentially a tracer of the Dark Matter distribution in the universe okay and our next question for Anna is um what theories exist to explain Dark Matter could they be a particle so at the moment the strongest theory is that matter is matter and is some kind of fful still because we haven't measured any of this particles yet or any candidate any good candidate for that matter there's another theorist going around telling us
that we don't understand gravity well enough to explain how the universe behav the problem with this theories is that there's not a unique way or a unique Theory to modify gravity to explain all the phenomenon we see related to that matter so the biggest consensus is that matter is matter and is some kind of okay and our next question is going to be for Alex um is the amount of dark matter in the universe constant over time so from The Big Bang to today so uh to the ability that we've been able to measure it the answer to that is yes essentially matter is a conserved quantity so even though the universe is expanding the total amount of matter in the universe appears to be
conserved and that's true both for normal matter so the protons neutrons electrons atoms all the stuff that we're familiar with in our day-to-day life and also for the dark matter okay and our next question for Dan um how does Dark Matter interact with normal matter so that is the question um we know that it interacts gravitationally because that all of the evidence that we have for it comes through that uh but in principle we don't know how it interacts with normal matter other than gravitationally there are a lot of reasons theoretically why it is preferable for dark matter to have some sort of interaction with standard model particles otherwise it's hard to come up with a theory for where the Dark Matter came
from if it does have an interaction with standard model particles we have actually spent a lot of effort over the last 30 years ruling out most of the types of interactions we know about there are still some possibilities that it might interact with the higs or other standard model mechanisms but in general people are starting to think about new mechanisms for Dark Matter coupling to standard model particles that are not part of our existing theories okay um so kind of going along with that maybe over to Anna um what are the current methods that scientists use to try to direct detect Dark Matter so there are lot of different experimental techniques for doing this and this is about what kind of candidate you are
looking for and Depends a lot of the mass of this candidate how this candidate May interact so basically when you're trying to build a detector you're thinking of what fundamental force is going to mediate what you have in your detector with the D marel par this can be for example a silicon Target that has nucleus and electrons and you can expect that matter to interact through a force that we know of a new force with the nucleus electrons in this T now if you go to something lighter you will have techniques more similar to the ones we use for measure light so it's all about what kind of candidate we are looking for and there's so many experimental and exciting techniques to
do so that research is pretty fantastic okay and we'll go to Alex for the next question does Dark Matter warp our view of the universe yeah so not only does Dark Matter warp our view of the universe but all matter does so this is one of the fundamental uh realizations that Einstein had in his general theory of relativity matter warps space and this means uh that light rays actually feel that warping as they pass by Massive objects so every clump of matter in the universe distorts the path that light takes a little bit and uh this effect is called gravitational lensing uh and because the Dark Matter actually makes up most of the matter in the universe uh the Min component for this
warping is the Dark Matter itself and uh we can actually use this to study the distribution of dark matter in our universe by measuring the magnitude and the locations of these warping signatures very cool I'm gonna stick with you again Alex um what role does Dark Matter play in the expansion of the universe yeah so uh so dark matter is uh interacts gravitationally it's in a it has an attractive uh gravitational force the same way that normal matter does and so as the universe is expanding uh it's the tendency of dark matter and all matter in the universe to slow down that expansion so it the Dark Matter pulls on other particles of matter in the universe and tries to slow the universe down uh so if there were only dark matter and normal matter in the
universe the expansion of the universe would be slowing down however we know that's not the cas from observations that have been occurring over the last several decades the universe is actually accelerating in its expansion and that's a whole another mystery that we call Dark Energy uh but I think we may need a different day to talk about that understandable dark energy is quite the topic um okay I'm gonna go to Dan can you answer what Axion are Maybe uh so Axion are one of the leading candidates uh for Dark Matter uh interestingly some theories of Dark Matter actually have the Dark Matter behaving a little more like a wave than a particle uh and Axion are one of these wavelike dark matter models the thing
that is particularly compelling about the Axion among the theoretical models that we have that could explain dark matter and that experimentalists like us are looking for is that it actually solves a second problem unrelated to dark matter in Quantum chromodynamics and so this makes it a favorable Theory because you have a single solution for two problems two birds one stone and so that's why people like searching for Axion and overall it's a very unique and interesting classification of Dark Matter models okay so speaking of other candidates I'm GNA go to Anna for this one Anna can you explain what wimps or weakly interacting massive particles are sure so again I mean this is another candidate for that matter the same way as D was talking
about actions we have whims are a little bit higher in the Mas is many order of magnitude more mass than what you expect from a wi from a ation sorry and it's a kind of particle that uh will interact through a scattering they I mean they are likely to do it through a force that we know which is called the wi nice things about the whims is that they work well with other FS like particle phes whims a long time ago was something that we can definitely or we could we thought that we could measure in an accelerator but we haven't measured any wind yet so now we are thinking about other candidates for that matter okay and we're GNA go to Alex for our next question what role does Dark Matter play and Galaxy
formation yeah so uh so galaxies form uh when normal matter which is largely made up of uh protons but also electrons and neutrons uh collapses under a gravitational force uh is able to radiate some energy to allow that collapse to proceed uh to sufficient density to start forming Stars uh and so galaxies are formed of collections of stars uh however that gravitational collapse is aided through the existence of dark matter so galaxies tend to form in regions where that are overd where there's more than the average amount of dark matter and so uh galaxies actually are seated in their formation by the distribution of dark matter so is that connected to the cosmic web that I've heard about that's right so uh
the cosmic web is uh is the observed filamentary structure of galaxies uh the locations of galaxies in the universe are not uniformly and randomly distributed but they tend to Clump and cluster uh and that is uh that is essentially showing us the galaxies are visible tracers of the underlying skeleton of dark matter which makes up our universe okay so our next question I'm going to go to Anna again um so we've talked about wimps we' talked about axons are there other Dark Matter candidate particles that are interesting to talk about for today that's actually a really great question because this is the kind of D matter I look for which are like d matter again there's many candidates and many possibilities there later
matter uh what we think about is uh particles that can interact mainly through new forces and they can perfectly scatter with the matter that we know like for example silicon or some novel gas and so on so yeah I mean there's a lot of experiment looking for uh these new candidates that are getting more and more importance okay and next question for Dan what is the difference between dark matter and exotic um I'm I'm not entirely sure I understand the question do either of you have anything you want to say on that one maybe you could talk about some exotic types of matter I guess I'm not sure what types of exotic matter the question is asking about yeah I mean I think uh exotic is not a formal term that I think we're familiar with or we use but
matter does exist in a variety of exotic configuration so in the in this in particle colliders for example there are Quark gluon plasmas under extreme pressures and temperatures uh matter can behave in very unusual ways uh and these are often thought of as exotic conditions another example is say a neutron star which is an extremely dense object essentially has the density of an atomic nucleus but the size of a city uh and in that case what you have as your fundamental building blocks are the standard model particles so uh protons and neutrons which themselves are made up of quarks and gluons it's the same building blocks uh of the universe that we see and interact with in our daily day-to-day
lives uh however they're behaving in unusual ways because they're under very different conditions than we normally observe them on the other hand dark matter is something that we believe is fundamentally different uh for the very uh reason that Dan talked about that we don't see the normal interactions occurring in the way that we see them occur for standard model particles we interact through gravity but not through the electromagnetic force or the strong or weak nuclear force at least not in the ways or at with the strength at which we see normal matter interact or standard model particles okay um and speaking of neutron stars we do have a question is it possible that dark matter could Clump
together and form objects like neutron stars or nebul or black holes even uh the top level answer is yes so we know at some level Dark Matter does Clump together uh it forms these diffuse CL clouds that galaxies live within we call those clouds of Dark Matter Halos you could think of it as a Halo of Dark Matter surrounding a Galaxy so at very large scales we do know that dark matter like other things that respond to gravity does Clump and cluster together uh as you get to more um uh different particle physics models of Dark Matter uh that have different interactions uh those interactions can allow Dark Matter to further dissipate energy and allow it to collapse into even denser objects uh there are H hypotheses of Axion stars or uh
basically wimp zillas all of these crazy well crazy but very uh unusual objects that could form from different particle physics models of Dark Matter uh in addition wimps which could interact with the standard model particles could lose energy that way and there are ideas that potentially in the very early Universe there could be stars that were powered by Dark Matter Annihilation um so everything's theoretical uh at this point uh at this point yes though we do search for observational signatures uh that could come from these objects if they exist if I may add to that on one of the Alex covered a lot of that one of the other ones the idea of black holes being dark matter has long been a theory uh
specifically what we call primordial black holes and actually we've made a lot of progress in ruling out models where primordial black holes make out the majority of dark matter it's still not fully excluded but even though we haven't found Dark Matter the experimentalists who work on these kinds of things have made an enormous amount of progress uh improving our understanding of what isn't dark matter and so that's a case where we are continuing to probe these different cases and hoping to learn if we don't find what dark matter is we're at least learning what Dark Matter isn't okay and that's always important with science um so we mentioned primordial black holes just real quick to Define them for audience those are black holes that
formed pretty close to after the big bang yeah that's that's exactly right so uh there are black holes that form as The Natural end product of Stellar Evolution essentially a star uh blows up and what's left over is a black ho uh those black holes the the matter that they contain was originally uh normal matter standard model particles and so when you're talking about the total matter budget of the universe you would count those black holes as part of the normal matter however uh there are theoretical ideas that in the very early Universe you could form black holes directly uh through um through basically uh very high density regions in the universe which could be related to inflation or other things that happen very close to the big bang and if that's
the case they would have been formed not from any standard model particles but directly from the starting point in the universe and in that case they wouldn't go into the standard model or the normal matter budget they would be something different which could account for some amount of the dark matter okay um Anna we have a question about Dark Energy but I want us to Define it first so can you define what dark energy is so I mean this is definitely a question for Alex but I would say it's very simple when we look at the universe we see that the universe is expanding acceler in an accelerated way this doesn't make sense if there's not an energy in the universe that allow for this kind of expansion and this is
what we call the r but maybe Alex you want to okay great all right I'll go to Alex for the next one sorry Alex um is dark matter and dark energy beli to function in a similar way to what we can see as energy and matter ah good question um so we we don't believe or the there currently isn't observational evidence and there are there are abundance of theories for what could make up Dark Energy um but one in which uh you exchange dark matter and dark energy in the way that you can exchange matter and energy in the standard model essentially through eals MC s uh is not believed to be the case for dark energy and dark matter uh and the fundamental way to understand this is uh going back to the question that was asked earlier about
whether the total amount of dark matter is conserved in the universe the answer to that appears to yes whereas a as the universe expands the amount of dark energy in the universe is increasing and so you're not just trading dark matter for Dark Energy uh in cosmology they appear uh to be different connected differently from the way matter and energy are connected uh in nor in the normal matter okay and our next question will be for Dan um does Dark Matter interact with the higs field so that's a really good question I think I might have mentioned this in response to an earlier question but we don't actually know what the Dark Matters interaction to the standard botel is aside from Gravity there are theories
for how dark matter could interact with standard bottle particles through the higs field in particular if it is a more traditional weekly interactive mass of particle like Anna talked about but at the at the moment those are all theories and we are in the process of testing a lot of those models and actually many of the models that involve the simplest coupling through the higs will be tested in the next 5 years or so okay and our next question I'm G to give to Anna um how would our understanding of the universe change if a dark matter particle was discovered can you repeat the last part please yes how would our understanding of the universe change if a dark matter particle was discovered oh
wow okay I have to say these are really great questions and not that easy to answer so basically uh if we find a candidate for that matter first of all we need to verify that this is actually that matter I this is the that matter we see the UN we might find a new form of matter that is not exactly the same dark matter we are seeing uh in all the phenomenon related to gravity so there's going to be a lot of work from the community to uh characterize this kind of uh new secets and then I mean this could be a breakthrough this will be probably the biggest breakthrough of the century and we'll open the door to understanding much more of the universe than what we currently understand we
only can explain 5% of the universe to the standard model particles that matter can be the clue to understanding the other 95% and that maybe sound a little bit ambitious but maybe true as well yeah um I'm gonna go back to Dan for our next question do we need matter to explain Dark Matter could dark matter be just a curvature in SpaceTime or in Quantum Fields okay good so this is this is a great question and it's one that we get a lot as dark matter physicists and it's actually one scientists have been asking for about 30 years now and one way to phrase the same question is dark matter actually a new type of particle or is it just a flaw in Einstein's theories of gravity uh and
essentially at this point after a lot of research and a lot of observation you really can't modify gravity to account for Dark Matter it just doesn't work there are still people who work on this because it is and has been a very interesting direction of study but basically what that direction of study has found is that because we observe Dark Matter on so many different scales from the galactic scale all the way up to the cosmic microwave background you can correct gravitational theories in a way that accounts for the observation of dark matter at one scale but it will then break physics at every other scale we haven't actually found a way to modify Einstein's theory of gravity in a
way that accounts for dark matter at every scale and for that reason we are becoming increasingly confident that dark matter actually is a new type of particle and not just a something incorrect in our theories of graphing um so following up on that with another question um is it possible that there are multiple explanations at once that could contribute to the phenomenon of Dark Matter absolutely um and I think at this point that is becoming increasingly likely so normal matter makes up 15% of the mass in the universe dark matter is about five times as abundant and so the idea that massive amount of mass in the universe would only be made up of one thing is maybe simple and very nice but the universe is messy and sometimes that
also makes it beautiful and so uh we very much consider the case where dark matter is actually part of what we call a Dark Sector hidden sector where there's an entire new class of particles where they maybe interact with the standard model and what we observe through a specific set of interactions which we're searching for but that there could be an entirely new um regime of physics to study through that dark Cent oh that sounds very exciting I love that as a particle physics lab more particles um Alex our next question I'm GNA ask for you why do we need to learn about dark matter or why do we want to yeah so um I think there's to some extent an innate curiosity that we have as humans about uh about our universe about our
surroundings uh Dark Matter does make up roughly 25% of the universe and we uh know very little about it uh in contrast all of the stuff that we normally uh interact with makes up about 5% of the universe the rest being dark matter and dark energy um and so I think that as scientists it's very unsettling to us uh to think that all of uh all of the things that we know and we understand make up such a small fraction of what is out there in the universe um that's sort of the philosophical reasoning behind why we want to do it uh the and the more practical reason um is complicated we in some respects we don't know what practical applications may come out of the discovery of dark matter but we can say that the
technology that's being developed in the search for Dark Matter uh has been very powerful and does have a number of applications uh and I might even turn it over to Dan to talk a little bit uh about some of those Technologies and other applications yeah sure so I mentioned at the start of this that most of my research nowadays is actually in Quantum Computing uh and so one of the reasons that I made that shift from Dark Matter to Quantum Computing is that uh by its nature a Quantum System incl including a quantum computer is very sensitive to interactions with its environment uh and that can be any interaction with the environment including potentially dark matter but also all of the normal radiation that is
coming from the materials around us including the standom model particles that make up us and the chair and the camera and so all of the technologies that we've developed for detecting dark matter that build more and more sensitive detectors and helping to isolate those more and more sensitive detectors from their environment are now being applied to quantum computers to make better quantum computers that are more is isolated from their environment for actual real world applications and so it's it's a direct uh example of how this investment and uh decades long research into building these what are essentially the most sensitive detectors ever designed has resulted in technologies that are now
directly applicable to something that has real societal implications that's exciting um I'm gonna go to Anna for our next question if wimps break down into visible matter doesn't that change the ratio of visible matter to dark matter in the universe okay uh so that's actually a very good question uh I need to think about a little bit maybe done I did what was the question if wimps break down into visible matter doesn't that change the ratio of visible matter to dark matter in the universe by breakdown do you mean Decay okay so good okay so at this point we can put a lot of limits on Dark Matter decaying into standard model particles okay um and basically if Dark Matter did Decay into standard model particles at any rate
that was significant it would change how the matter density of standard model particles evolved over the course of the universe now for certain regions of the universe where dark matter is extremely dense for example the galactic center you can still look for incredibly rare things like dark matter Decay or dark matter annihilating with other Dark Matter particles into standard model particles and that does allow you to probe different models but in general there is no significant decay of Dark Matter into standard okay that makes sense um our next question I'm gonna have each of you guys answer it um do you have a favorite candidate for a hypothetical Dark Matter particle um I'll ask for clarification
do you want favorite in that we think it is the most likely to be true as a like prior or favorite in most fun let's be less controversial and go with most fun okay that's interesting um most fun um I really like I this is boring but I'm probably going to go with wimps because I can study them and so it's the most fun for me because the wimp would be the most easy to probe um that's a really boring answer I mean that's why I like neutron stars more than black holes because we can actually study them a bit more so I actually have um I was going somewhat similarly in uh in that the most fun Dark Matter candidate for me would be the one that we can learn the most about and uh and since I do cosmology and I observe the universe the
class of Dark Matter theories that I think are particularly fun or one class that is particularly fun are self- interacting Dark Matter theories so these are theories where Dark Matter may or may not have any significant non-gravitational interaction with the standard model with normal matter but it has interactions with itself that allow it to scatter and exchange momentum this leads to something this can only occur in it in a model where you have sort of a Dark Sector so that the Dark Matter particles can exchange information through some other Dark Sector particle uh but this then allows you to get really interesting features in the distribution of dark matter in the universe and you can start thinking coming up with thought experiments about
like if you were looking at the distribution of normal matter what could you learn about the particle physics of the normal matter you can try and apply those same kind of thought experiments to if I can measure the distribution of dark matter what can I learn about this mediator that's connecting transferring information from one dark matter particle to another so self- interacting dark matter I think is very fun so going to the fun part matter right so as a passionate about instrumentation I always like to think about that matter candidates that allow us to develop very cool technology for them uh in particular I like exotic ideas that push our imagination that push us to KI outside box and try to
discover new technologies and new technique to measure this uh these FS I like whims but we know how to measure whs right so yeah I like more like than M all good answers good job guys um so our next question maybe Alex can help with um has or will the James web Space Telescope impact our understanding of dark matter and how so uh yeah so the web telescope has a few different impacts on our understanding of Dark Matter uh one that has uh that has gained a lot of interest recently is in uh the web telescope's ability to measure very distant galaxies that formed very shortly after uh the big bang so early in the universe's hist history uh and the observations are still coming in now they're still being interpreted and
refined but early on there was uh there was interest because some of the galaxies that were being discovered by the web telescope uh were brighter uh and more massive than had been naively expected before web had started taking images uh and this led to a number of very interesting theoretical interpretations including interpretations that uh called into question whether our standard model of cold Dark Matter could produce galaxies that were as massive and as bright uh as quickly as they were being produced uh and seen by James web um so this led to theories and talk about uh primordial black holes which we just talked about recently um it's also uh LED uh led to ideas about other um part particle Dark Matter models that could lead to gravitational collapse
occurring more quickly um so that's one way the web telescope has really uh been shedding light on this dark matter question I can talk about more uh as well but maybe we'll we yeah I think our next question is a is an important one to get to um and maybe you can each kind of talk about it um what firm laab experiments are looking for dark matter okay so there's a lot of these experiments I will talk about since which are experiments work but these are experiments looking for light and matter with a silicone Target so the idea that you can have a light and M particle interacting with the Silicon nucleus and of the Silicon electrons and then we have the most sensitive sensors in the world and we can look for that matter
producing one electron in my silicon Target um we have other experiments going around uh exploiting new technologies and maybe I mean that you are working on this directly techology um well if we're talking about to be to be um complete uh some of the other experiments at forab looking at dark matter include super uh which uses cryogenic detectors uh to measure uh the very small energy deposit of dark matter in the crystal um but beyond the more traditional experiments like the CCD experiments and cdms uh there's a number of more uh Cutting Edge more um next generation is the right word uh experiments thinking about how to do this um that includes things like a project Alex and I are working on where we're using uh Crystal
scintillators uh equipped with photo detectors actually using ccds as the photo detectors to try to search for dark matter or looking for Dark Matter presenting a noise source for quantum computer computations uh like what I do in the lab um I don't know missing uh we're almost certainly gonna miss some and uh and we AP we apologize as well so just a few more experiments that firul lab is running so there's the Axion Dark Matter experiment which firul laab is very heavily involved in uh there are the collider experiments so uh at the so CMS at the LHC is a has a potential to create Dark Matter uh well the lhd has the potential to create dark matter which then could be detected by the CMS
and Atlas experiments uh there are the neutrino experiments which also have sensitivity to some models of Dark Matter physics and uh I know Dune is a future experiment that fmab is working on that will have some sensitivity to dark matter as well uh and then there are the cosmology experiments like the dark energy survey other experiments that work on with the dark energy camera and the upcoming uh Reuben Observatory Legacy survey of space and time which all uh have the potential to well do improve our understanding of how dark matter behaves in the universe so and I'll just apologize if you're listening and we missed your favorite experiment that we work on but really it is a very large suite of
experiments that come at this problem from many different angles yeah and also a comment about this I mean this is one of the nice thing about the feel of that matter is that you can have very big massive experiments with your for whims or you can have very very tabletop laboratory experiments right and we do a lot of this in C formula so it's kind of impossible to account for all of did you want to add you're good okay I was just going to say the reason for the long list and why there's so many ways to search for dark matter is that name dark matter really encompasses most of we know about it and so if you are running an experiment that could be sensitive to new physics beyond the standard model there's a good chance
that includes new physics that falls under that classification of dark matter and so a lot of different science programs here at the lab are sensitive to new physics in different ways that represent very different types of models of dark matter um and I can touch a little bit on the deep underground nutrino experiment or Dune which Alex mentioned I reached out to one of our Dune physicists Sam Zeller ahead of time and I'm going to read her answer for whether or not Dune can detect Dark Matter possibly so the deep underground nutrino experiment will have sensitivities to certain type of dark matter in both the near detector located at fmy laab and the far detector underground in South Dakota at the Sanford underground research facility
the D near detector will be able to look for low mass dark matter in a unique Mass range that isn't reachable by existing direct search experiments theorists are particularly excited because the near detector can be moved off access from the nutrino beam which can improve the low mass Dark Matter search the far detector will also be sensitive to some dark matter specifically boosted Dark Matter coming from sources out in the universe such as the sun the galactic Halo and dwarf galaxies um so our next question I will pose to Alex um will Dark Matter lead us to a Theory of Everything uh I think the answer to that is we don't no um certainly it is uh in order if we had a theory of everything it would have to explain Dark Matter so I think it's a fair bet to say
that uh the more we understand about Dark Matter the better chance that we have of building a Theory of Everything uh but at this point we really don't know what is what it what pieces of the puzzle need to fall into place before we can come up with such a theory fair enough um Dan I will ask the next question to you um can you give more insights related to Quantum Computing in dark matter in the dark matter connection is there a way to understand Dark Matter using Quantum Technologies so there's there's a there's really two different ways to answer this question so the first is sort of in line with what we've been talking about with direct detection where you can imagine your Quantum chip which has you know something on the
order of maybe a gram or a milligram particles that dark matter can scatter out them and deposit some very small amount of energy in but because Quantum sensors and Quantum systems are incredibly sensitive to their environments that's actually enough interaction with the environment to change the quantum State and because you're doing calculations with the quantum computer it's very sensitive to any sort of uh errors that might happen due to interaction with the environment so in that sense you can directly use a quantum computer or a cubit as a sensor for Dark Matter a less direct answer is that quantum computers are going to change the way we do Computing in a way that's going to have really fundamental
and interesting applications to fundamental science um and that's because in the same way that uh a CPU and a GPU are better at different types of calculations a quantum computer is extremely good at solving uh very complex com uh interacting systems which will allow us to better simulate cosmological models uh and evolve those systems to better understand uh the constraints from cosmology on what Dark Matter might behave like and so it's not a direct probe in the same way that direct detection is but it will add computing power to simulate problems that with a classical computer we just can't directly do we have to make summations okay thank you um our next question I'm going to give to Anna um we love neutrinos at formula but can
neutrinos interfere with dark matter searches well actually yes uh neutrinos is one of the main backgrounds for wh seches and this is a funny thing like one experimental one experiment signal is another experiment background and we know this because of a lot of different situations but yeah I mean for um I mean the kind of Technology we use to look for neutros is very similar to the kind of technology that we use for search for some kind of D matter right and the kind interactions uh we expect to see in the Target are going to leave a very similar signal so yes I mean we have a limit to where we can look for uh that matter with a certain technology because we know we have neutrinos that will
interact in that region uh of what we call the parameter space okay and Alec or do did you want to add something yeah something really fun about that story is that so we've been detecting neutrinos now for a half a century but the main way that we detect neutrinos is through their interaction with electrons so what Anna is talking about here is actually one of the rarest interactions in the standard model where neutrino comes in and actually scatters off of the nucleus of an atom um and that is something that's just predicted by the standard model so it's not necessarily um a novel in of itself but it's incredibly rare and we actually only observed that interaction for the first time in the last decade and what
Anna is saying is exactly right our detectors have gotten so good that extremely rare interaction is actually going to present an irreducible background for our Dark Matter detectors uh specifically from neutrinos scattering through that process coming from either the atmosphere or the sun we love neutrinos but I guess for dark matter they're they really get in the way fair enough um I will ask our next question to Alex um how do you know dark matter is actually matter um so this is in some ways a definitional question but I guess it also gets back to something that Dan was talking about before so uh if one alternative to dark matter being matter would be if it were a modification to our understanding of gravity and that
ends up being very difficult to do across all scales so we call it dark matter because it behaves like matter um meaning that uh it behaves in a way that you can actually find situations where the dark matter and the normal matter are separated and that would be very difficult to do if you were uh if you only had the normal matter and then some modification to gravity uh so there are systems in the universe where you can actually uh measure the separation between the dark matter and the normal matter which suggests that dark matter is behaving like a matter component um okay our next question I'm gonna ask all of you to answer um what we talked about firmy laab Dark Matter search experiments um what other dark matter are happening elsewhere and maybe
to help narrow that down you can just list like the one you find most interesting or you'd like to specifically do a call out for do you want a SE answer yes but we'll start with Alex I'm gonna interpret this similarly to the last uh everyone answer question about what are some of the most fun ways uh that people are searching for Dark Matter uh and I'll talk about one because you know my expertise is in cosmology and astrophysics uh appro that's related to those and that's a search for um for a dark matter Canada that we've talked about before the primordial black holes so if Dark Matter were made up of primordial black holes that would mean that our Milky Way galaxy and its surroundings would be uh
would be full not of uh empty space or not of minute catomic Dark Matter particles but of massive black holes that are floating freely through space now these black holes uh through the process of gravitational lensing which we also talked a bit about before would uh would actually be observable when they passed in front of background Stars uh a black hole passing in front of a star uh would lead to that star getting brighter and then fainter again in a characteristic way and so over the past several decades uh astronomers uh have observed uh stars both within our Milky Way galaxy and in our one of the nearest neighbor galaxies the large melanic cloud and looked for this character
characteristic signature of brightening and dimming of the Stars uh from black holes passing in front of them and they found a few of these events but not nearly enough to account for uh all of the dark matter being made up of primordial black holes at least in a specific range of masses and so I thought I think this is a really cool experiment uh it's a prediction that can be observably testable and has been okay so I will try to go to something a little bit more fun and exotic not that for what I say like jally speaking uh I do like the idea of directional detection of D matter so this is basically I mean you are not only looking for D matter interacting in your detector but you also looking for
the direction from where the D par came from and for doing that you need to have some outstanding sensitivity and outstanding materials and outstanding technology to do it so even though this is still green I mean we are working on developing this kind of Technologies for the future it might be the only thing we can do after we keep on pushing the sensitivities and we start to have backgrounds that we cannot remove anymore like the nutral background so thinking about directional uh detection when it comes to the physics behind this the idea that you can actually see the direction of Ral particle is quite fantastic and all the is instumental challenges to get there are a lot and a lot of fun to
tackle so okay so two really good options were taken I'm going to go with something that's fairly traditional but hasn't been well represented in our conversation so far which is the large Xenon time projection Chambers uh so this is something that perb has been involved with in the past but there's no one here who currently works on it uh and actually the in certain Mass ranges the most sensitive uh searches for Dark Matter come from these giant tons scale uh Xenon detectors um what's really fun and interesting about them is that these are in many ways the most sensitive uh detectors ever built depending on how you define that um to the extent that they are now measuring ultra rare isotope decays as
their primary background sources that otherwise had never been measured because their halflife is just so long and so actually some of the dominant uh backgrounds coming from these giant Xenon time projection Chambers just come from really long lived Xenon isotopes with uh lifetimes on the age of the universe and so that to me is just incredible yeah all good answers thank you guys um our next question um how would you encourage uh non-scientists who are interested in science sence um to participate is there like citizen science projects people can get involved in so I'll take a moment to plug a citizen science project so uh astronomy and cosmology is really fun because we are taking pictures we're taking pictures of the night sky we're taking
pictures of really exciting and fun to look at objects like galaxies uh it turns out that there that this gravitational lensing that we've been talking about that allows us to actually measure directly uh the existence of dark matter and how much dark matter is in a system is in a galaxy uh can re lead to some really crazy looking images uh where the light of a background Galaxy is totally bent and distorted this is called strong gravitational lensing uh and in these systems you can learn a lot about the distribution of dark matter in a galaxy however they're exceptionally rare uh to find uh and one way that has been extremely efficient for finding them is through citizen
science visual inspection campaigns so basically having people look at images of galaxies and try to identify whether or not strong grav gravitational lensing is occurring there and there are several citizen science projects focused around this topic awesome thank you um I think our next question I'm going to POs to Anna um we kind of already touched on this but maybe just to clarify a little bit more um equals mc^ s uh regular matter can be converted into energy is that possible for dark matter to be converted into energy itself not dark energy yes I mean if their mother is mother and is a particle I mean the way we understand particles how they interact is transforming into energy and particles again so we would
expect this to Happ and behavior even though we don't know exactly the specific forms that are going to mediate this so in principle I mean we expect to have a similar Behavior than standard mod particles but in a very different uh ways somehow I don't know if that clarifies that it hopefully it does awesome and it looks like we have time for one last question um Al now that you have the mic I'll start with you um what are you most looking forward to in the next year so I'm really excited about the Ruben Observatory uh the Legacy survey of space and time that it's going to be carrying out is going to be starting about a year from now uh we're currently in the phases of commissioning this brand new uh
telescope a huge digital camera 3.2 gigapixel dig digital camera uh which is going to be on the sky very shortly and is going to be taking uh pictures of the nighttime sky at an enormous rate uh and so in essence we're going to be able to build movies of everything that changes in the visible night sky every three nights and I think uh that along with the uh extreme sensitivity of this new system is going to teach us a lot uh about Dark Matter dark energy and cosmology so uh Dan are you good to go for next yeah so uh that the question is somewhat hard uh for me as a direct detection person because the time scale on Direct detection experiments tends to be on the order of five or 10 years so
one year is a very short amount of time for me but I'll just answer it selfishly which is that um my the new lab we have been setting up here underground to run uh Quantum chips and cubits in a radiation controlled environment uh just came online uh this summer and our first cubits uh started taking data last week so I'm mostly just really excited to go underground and then be I will be underground a lot uh for the next year awesome yeah we love going underground at formula yeah so next year um personally I think I am very excited because we are going to start a new run with our experiment we recently achieved the lowest backround ever at you in any CCD and any light detector by the way so now we are going to start taking data
hopefully who knows maybe see a signal there maybe a little bit ambitious but fingers crossed all right um so it looks like that's all the time we have for questions uh thank you for Alex Dan and Anna for being here to answer our followers questions and thanks to everyone online for watching make sure to join us tomorrow in celebrating Dark Matter day on social media using the hashtag Dark Matter day for more information on formula dark matter research and experiments you can visit astro.fi laab news on LinkedIn Instagram Facebook threads and X Twitter thank you all for joining us today
