Imaging the Beginning of Time from the South Pole - Dr. Ahmed Mohamed Soliman - 5/8/23

hi everyone welcome and thank you for coming to our first everheart lecture series Talk of the year my name is Rachel Tam I'm this year's graduate student council academics chair and also part of the Everhart lecture series committee along with Pond and Syria who are also up in the front today the Caltech Everhart lecture series is sponsored sorry the Celta Everhart lecture series is sponsored by

The Graduate Studies Office and organized with the graduate student council the ever heard lecture series is a forum for outstanding Caltech graduate students to present their path breaking interdisciplinary research to a broad scientific audience the Everhart committee was amazed by this year's applicants and it was really challenging to select three speakers for this year so today is the first talk and the second talk will be

on May 22nd to my knowledge the most recent everheart talk was about five years ago so we're really excited to continue the series today I will now like to ask Professor Bach to introduce today's speaker Dr Ahmed Solomon thank you hi everybody I'm Jamie Bach I'm a professor of physics here at Caltech and it's my pleasure to introduce Ahmed Solomon our speaker today I am ahmed's

thesis advisor so let me give you his CV he got his bachelor's at Ben Hall University and his Masters at in Chums University both in Egypt both in electrical engineering and is now completing his PhD in engineering and applied physics at Caltech just as soon as that thesis is submitted ahmed's a well-known and popular figure around campus especially among the graduate student committee Community where he

was a grad organizer orientation leader for the past three years I can tell you one story also about Ahmed so he approached me as a double e student first or second year graduate student and said he wanted to do something fundamental and I said boy have I got a job for you so Ahmed has been applying his electrical engineering skills to the particular technical challenges we

have detecting the microwave background to understand the beginnings of the universe and as a sign of his determination about a year and a half ago he was one of four Intrepid graduate students whereas we would normally send a team of about 20 people in the Antarctic summer to service the instrument we could only send four and those four were the first to go back and service

the instrument after the pandemic which involved many days of quarantine at different locations but just shows the enthusiasm and determination that Ahmed brings and um and you'll also see that Ahmed has an infectious enthusiasm for Science and applying a love of applying his unique technical skills to um you know make our measurements possible so without further Ado I'll give you our speaker tonight Amit [Applause] so

uh thanks so much Jamie uh for the introduction I'm really proud to be here today and I would love to start my talk with citing Professor Ahmad zuel's statement is uh coming from the land of civilization in Egypt to the land of science at Caltech without being able to speak English and mixing some more this together like smell and the smile and I have learned to

make contribution to science with my great team members in the observation cosmology group at Caltech leading by Professor Jamie buck so I'm really happy to be here today to basically share with you my passion about science more specifically Mobility journey in capturing the first few moments of our infant Universe at the South Pole so as you can see here this is our telescope at the South

Pole and this is I took this photo at the end of the deployment season last year and the temperature was like minus 50 something solidius which is really really cold and I was taking some on Sky measurement and I see this really nice beautiful ring around our telescope which is really nice so um so first I will start about what we have learned so far about

our universe from the modern cosmology so back in 1920s we knew that the universe is expanding from Edwin Hubble observation and then in 1940s from The Big Bang nuclear synthesis about the production of the Light Elements in the alien Universe we knew that the Universe was extremely hot and dense but the major observation uh came out from New Jersey in 1965 with Wellston and benzias so

the two radio astronomers Robert Wilson and ernobincias were basically doing some communication radio communication using their horn antenna and they did this basically is addicted some background noise and they didn't know where it come from so they basically checked everything all the possible causes for this background noise the clean out cleaned up the antenna just check everything it didn't go away and then they didn't know

where it was actually coming from and then eventually they basically start to talk to the scientific Community more specifically the professor or astrophysics Robert Dicky at Branson University to basically ask about this and the and it seems like they were backing one of the most interesting discovery of all time which is the lift over radiation from the early Universe which is the cosmic microwave background and

this the detection of cosmic microwave background was greatly support the Big Bang cosmological model to explain the origin and the evolution of the universe um so if we can look at the the Big Bang cosmological model which basically proposed that the Universe has a finite age so at Time Zero the universe was extremely hot and dense and then start to cool down and expanded those time

until it come until it reached to the thermal equilibrium temperature here that allow for Broughton and electron to combine together and to form the neutral hydrogen and which what we call the surface of the last scattering and we and here the CMB photons basically formid and the universe became transparent to this Photon to freely stream the universe through the universe and this is what we can

see today by our telescope to the CMB basically it was a prediction of the big bang and this is really useful tool to study uh the earlier time about the universe however it you know even it's it's answer some question it also bring more questions which is what's troubling for the cosmologists especially in 1980s as I will show in the next so what happen if you

look at the sky so the sky you can see that we have the sky contains many astronomical objects that can produce wide range of radiation you're talking from Radio all the way to gamma ray with different wavelengths like too short or too long for our eyes to see so if you look at the sky for example at the optical wavelances you can see beautiful planets and

the Stars however if you look at the same sky but at millimeter wave lenses you can see something else which is the cosmic microwave background which is two around 2.7 7 Kelvin everywhere so basically the the Big Bang model assumes that the universe is expanding over billions of years meaning that the photons from the early Universe should have never been in a causal contact however the

observation of the CMB indicate that the the temperature is the same everywhere which is something contradict the Big Bang Theory and the Big Bang model doesn't explain that and this is one of the first problem with the big bang the second problem as you can see this is little diable effect here that I will explain because it's like uniforms like one part of ten thousand uh

you know as measured recently by blank satellite the second thing we learned from looking at the sky which is basically the CMB an isotropist so if you subtracted the large Factor term from the equation you can see this little variation in the temperature on the sky you can see that how we just improve it from the kubi satellite in 1992 all the way to by blank

satellite so we can look closely in this feature which will tell us more information about the universe so if we zoom in at the small angular scale you can see this little spot you can see some high and low density spot which reflected the acoustic oscillation in the blasma in the early universe and also it can tell us it can tell us something which is the

the angular distance between this adjacent CMB spots can tell us the universe is flat nearly flat so let let me let me clear so the science says the universe is flat but not earth so yeah so which is predicted by the inflation so but the the Big Bang model doesn't explain that because the Big Bang model assumed that the expansion of the universe through billions of

years should drive the universe to be the total uh the energy Dynasty to be away from one meaning that the Universe should be curved not flat so we don't understand that from The Big Bang which is the second problem we call it flatness problem the third one that we don't know is perturbation sources that we can see in the CMB map what is the sources of

this perturbation that see the formation of the largest structure through the universe that we can see today so all of this question can be solved all of this question were troubling questions for the cosmologist in 1980 and that's why uh you know we think that you know looking here is not enough we need to give back further in time and see what happened here and that's

why we come to the inflation so the inflation theory was developed in 1980s to explain the initial condition of the universe and solve this problem by proposing there is explanation expansion at the early universe and the fee the quantum fluctuations here in the inflation field um just stretch it out to larger scale that forms the larger structures meaning that also the inflation also solves all of

this problem by suggesting that all of these photons should have been at the thermal equilibrium in the early Universe which basically solve with the the high uniformity of the cmbs that we see today but at the same time the inflation predicts something which is the squeezing space here squeezing at the stretching in both dimension can basically imbrent a pattern here which is called B mode pattern

in the CMB to this B mood batter is basically an indication or signature of the of the gravitational waves from the inflation which basically is going to be it's supposed to be imprinted in the CMB and it's supposed to travel all the way and we should see it today which this is the signature what we're looking for the beginning of time signature for the gravitational waves

I will give you here an example so for example we have two times of density two time of waves we have density wave which basically is sources by scalar perturbation and we have gravitational waves what's sources by tensor perturbations so you can see the electron here see the hot and cold spot in Barrel or bandicular to the propagation so you can see that the resulting pattern

which is called e-mode polarization better however if the if the if the the electrons you know just located in the gravitational field and the gravitational waves it can produce quadruple pattern which is different so the dynasty wave can generate something called immobilization pattern however the gravitational waves can produce pause the E mode and also a unique source of the B multiplication pattern as you can see

it here as you can see it's here so yeah um which is the signature of the inflation that we are looking for um so now we're gonna ask a question is this is easy to detect let's see it's very hard to detect because you know it's we're gonna explain just next so if we if we want to see how we can detect this B mode there

are so many challenges the very challenges is very different signal so if you look here at this plot it shows you the signal power you know at versus angular frequency so we have the temperature which already what we can see today the temperature of the CMB and you can see that the e-mode polarization which already first detected in 2002 by Desi experiment and you can see

that it's a very bright signal and you can see also something called lensing B mode which is another signal which is you know coming as a resulting of some Distortion of the light coming from the alien universe so we have emot here it resulting to B mode at the end so that's why it gets deviated by lensing that's we call it lensing B mode and the

last one that we are looking for which is this one so and this is the bromodial B mode polarization and this is what we're looking for so we often that you know we often describe our attempt to detect this wave uh with like while the ghost chase because we don't have an absolute confidence of its existence however the inflation model predicted that it can be detected

at predictable levels so we're still trying but as you can see that it's a very faint signal compared to all the bright other bright signal here which is very very difficult to detect and also it contaminated by some lensing here and this is show our efforts that we're doing with the South sport telescope team trying to characterize this lensing and remove it from our CMB map

so we can able to detect this so this is if this is the only challenging no we still have one more challenging which is the the existence of the polarized foreground so the gravitational waves is not the only waves in the universe we have other waves it's called Uh borerized foreground so the brass foreground we have two mean polarization you can see that we have syncretron

which coming from the radiation of electrons in our galaxy magnetic field and is dominated at low frequency and we have the polarized thermal emission uh which coming from the interstellar space and also dominated at high frequency so we need to basically characterize this and you can see it's like 20 Kelvin and the gravitational waves are talking about Nano Calvin levels so it's a very thin signal

compared to other signal exists so when you look at the map now you can see that it's the our CMB map it's covered by all of these three sources and we need to characterize precisely this result forces to be removed from our CMB map and to do that we do multi-frequency observation from 25 all the way to 300 gigahertz to be to be able to characterize

this signal and remove it from our map and also this gave us that we need to design a high sensitive instrument to able to look deeply in our map and be able to detect this signal and this is basically our Target in bisect care collaboration team so that I'm really proud to be part of the ongoing effort so you know this brilliant mind are working very

very hard from the design testing all the elements all the component of the telescope all the way to deployment and science observation at the South Pole and we have been doing this for you know decades like two decades or like three decades now so so the South Pole the the bicycle experiments are located under Amazon South bull station so someone will ask okay the CMB is

everywhere around us why did you go to the South Pole so from the CMB signal or the definition Cosmic micro background so it should be located in microwave range so the wetter the the water vapor absorbed the microwave already so and to avoid that we need exceptionally dry sight and the South Pole is ideal side for that because it has altitude of like 10 000 feet

above the sea level and this is one thing that why we would like why we do observation at the South Pole also it's exceptionally cold and it provides excellent micro transmittance and that is and also the location of the South Pole with respect to the earth makes that the the sky is visible to us all the year which means that we have longer integration time so

we started our program in 2010 with bicep 2. um you know to bicep City and then all this shows a progression all the way leading to the latest telescope which is the topic our bicep array so as you can see here we have improvement from from here all the way to the end and because we do we improve the sensitivity of our experiment um by ex

by actually making multi-frequency observation or my by making like increasing the number of detectors to collecting more CMB photons to be able to detect this fan signal and this is basically uh what you can see here and then the site is supported by the National Science Foundation I see some people start feeling cold uh yeah the site is supported by the National Science Foundation um and

uh you know they support us with what we need in the station can anyone guess what is the temperature this is actually me in the station at last year can anyone's you know trying to guess what the temperature yeah it's like minus 57 Celsius which is really really cold uh yeah so the the so and then we we deployed one we after we deployed the the

NSF awarded us was uh Antarctica surface medal of United States just a recognition to our deployment effort and just like exuberation we did at Paul so then we can zoom in to the telescope concept yeah uh we can zoom into that so we basically designed our telescope to be compact as possible but at the same time having the angular resolution to observe the B mode patterns

that we are looking for the signature of inflation and gravitational waves and this is the mean corpse concept for Designing our telescope so we move from Cake array to bicep City they can see that we have like you know if we zoom into the focal plane you can see this photo so this is for Keck this is for bicep tour Keck and then we just like

five times bigger here so we can see a large number of detectors to be able to collect more photons and you can see we cool down the Optics all the way from 300K Kelvin 50 Kelvin all the way to uh four Kelvin just for low background looting and all the way to the focal brain 250 Milli Kelvin and this is you know we observe one percent

of the sky for higher accuracy um you know we just need to go deep as possible in our Maps but if you if you if you would like to zoom in one of this detector you will see this so this is one of the detector module underneath the telescope so we receive the CMB Photon by orthogonally polarized array of um of slot antennas doing independent measurement

of the CMB and both polarization vertical and horizontal polarization and you can see that we receive the photons and you can see that the swan polarization and this is a second polarization and then after that we have some filtering to basically filter out this signal and remove our our band of interest and just like Define our science band lower and higher cutoff and then after we

collect all of the signal is going to be terminated in the transition in the sensor barometer which is very very sensitive to any small change in temperature and this is what we read out and then ok so what is the current science status what is the current status now this table shows that the detection of the B mode has inspired lots of Engineers and scientists around

the wallet to build the experiment to be able to detect the signal because the detection of the signal the signature of the inflation will open the door to probe the energy scale of the inflation when the universe was a mere fraction of second old after the big bang so you can see the blue here is our effort and the black you know other efforts other experiments

and you can see that in 2004 you can see that Improvement on the on the the upper bound um you know the the since the sensitivity on the gravitational waves going improved all the way to here which is Big 18 our result so we basically the growth of the the growth of the Improvement of technology in our experiment has led us to be basically the only

the leading to both the world in leading constraint and the Bermuda gravitational waves through our latest paper in physics review letter so as you can see that we have Improvement because we increase the number of observation we increase the the integration Time by increasing the number of observation years we have multi-frequency observation we have more detectors that's why just you know b key 18 which means

data collected up to 2018 season so we only just three years or 95 plus some 20 20 gigahertz data can make uh this just the wallet leading constraint but this is not enough because this data is still yeah this might be the question if we have the world leading constraint why we cannot detect as a b mode and the reason is the B mode the the

detection or the this result is still limited by lensing or variance from lensing and also the foreground which leading to the motivation for the latest bicep array telescope so by separate telescope will basically map the sky with all frequency from 30 gigahertz all the way to 70 gigahertz with the goal with the goal of characterizing the polarized foreground so as you can see that the first

receiver at 30 40 will basically characterize the synchrotron and you can see all the way at higher frequency as I just mentioned the burgers foreground was dominated by dust so that's why this will you know will map the sky with unprecedented levels which hopefully can improve our ability to detect the B mobilization also at the same time we're doing some effort with spt to basically characterize

the B mode the lensing B mode from our Maps which is the second factor that we are trying to get rid of so to be able to detect the signal so if we will start with the first receiver which is this one so this is a focal plane and this is where we receive all the CMB on the sky which is care which is houses 12

detector modules and with a special design you know you know details like here in the frame we have a special corrugation feature to minimize all the Big Sea located to near the frame and also you know each of this module has like 2016 to 25 pixels depending on the observing frequency and if you zoom in one of the pixel you can see this which is you

know we observing in tubularization which is you know for example give you this one but also in at 30 40 we did we Implement a new technology to the new technology is replacing this slot technology with the bow tie so zabota you can see is collecting more photons more than what we normally uh use before which is something you know that we realize we implemented in

our detectors at 30 and 40 gigahertz and then we use design especially like filter here to split the band between these two observation at you know spillated like here and like here and we designed to be away from this line This is atmospheric power spectrum and we need to be away from this green line because this will just like you know increase our noise in the

detectors so after we design it we start to do the integration and testing so this is our team so if you want to look at the telescope from down here you can see me so this is the Disco from the bottom and you can see that I was like doing some connecting wiring and thermometer at the middle and this is my colleagues Lorenzo me Alessandro and

Rito we were doing you know doing some surgery in the focal plane and this is my colleague Chang she is you know working with me in the draw frequency receiver and this is my our friend Ben from Harvard University as he was responsible for implementing the optical element that we have it in our telescope so we did you know a great teamwork of like collecting everything

together and yeah I put some sign here to show the vocab Lane Optical Optical element and then just like you're thinking about few years of runs you know integration time by time until you come here after we you know for example this is one of the Run we just bought some module here inside the focal plane and then we'll start to close up putting all the

shells and you can see me and Alessandro this is one of the lenses that I was talking about which is used to basically direct our detector beams to the sky so and then after we you know closed closed out our receiver and did all of this work in Caltech we start to um uh to do the measurement so we did we perform it in Caltech all

the required measurement to make sure that our telescope is working really well and I show here an example which is trying to validate our Optics design our detector design by seeing one of the detector map for example to to show that this is the detector are working and the reason for this that we need to provide that to validate our design before deployment to the South

Pole and you can see that one of the example of one beautiful map and this is the polarization different because we map the polarization with an orthogonal uh like vertical and horizontal and we take the E minus B so we need to minimize uh we have minimized systematic errors so after we mix after we did all the required testing everything it's time now to go to

the South Pole to do science observation and uh hopefully get some you know information about the alien universe so we ship our tele scope to the South Pole and then we individually just like go to from here to New Zealand and as you can see that you know we use we we have their United States Antarctica program support center which basically used to you know deliver

all the stuff giving us some courses about what we need to do to be careful at South Pole you know you are going to the coldest place on Earth so then we moved from New Zealand to mcmordo Antarctica was like minus 15 degrees Celsius is is not bad you know to us those house phone is not bad yeah using the U.S Air Force and then uh

I actually took this video just for my kids you know and Aaron because I show them yeah this is a cool uh you know Antarctica mountains just to show my my kids while I was like uh you know Landing to the South Pole yeah and then go to the South Pole and as you can see that you know the you know that the brain is just

landed here to you know land some people and take off another back to the state at the mcmordo and this is our lab at the South Pole so we I went to the South Pole twice the first one before Kobe the second one during covet and the during covet was really really difficult because we spent a lot of time in quarantine and we we had we

have to go in the whole season so we see a little bit of the winter the winter that you can see that it's really really cold that's why we touched minus 50 something celestials especially in the second season and then you can see that this this cool video would show us uh what's going on at South Pole so this is our lab at South Pole and

this is our uh uh station where we live in so we walk like almost uh you know a few minutes from the station that we live in all the way to our lab and just working at South Pole sorry it's my bad video so I will say hi at the end uh yeah it's uh I I just recorded this moment because it's really it's really exceptional

for me um and yeah then just like we work like every day all the way just really cool cool you know uh cool stuff to see at South Paul and then I'm just saying hi yeah it's uh then then we go to uh the South Pole and then when we go inside our uh our uh our lab we are fine now no cold nothing that's why

you see us like normal people uh so inside you know the the lab already is already contained to preserve you know room temperature that we can work we can you know because after we received our receiver we start to assemble everything together and this is our receiver team and do all the calibration work everything to make sure that you know a lab calibration work and everything

as we did at Caltech plus we do some uh you know to make sure everything is working and then after that we load the telescope to the mountain to start to do some science observation to the first year when we deploy the telescope we got some beautiful news which is we can see temperature map at 40 gigahertz for the first time in our experiment because we

usually make observation at 95 gigahertz on the above so we see we got some temperature map from the receiver in the on the sky which is really good news because it's comparable with a reproduced blank map at 45 gigahertz you see it's pretty much identical and also the first season we got some good news which is the the you know because the first receiver the the

main goal for the first receiver is constrain the syncretron foreground and you can see that we are improving the upper limit for you know sync control for getting out amplitude by factor of two but so what about R we see no effect and the reason that we see no effect because the 220 season didn't reach the design sensitivity and the map depths so it was something

wrong and we need to figure it out and the wrong thing is we found that we have some higher loading our detector experience some higher loading than expected and this loading coming from higher frequency to this example for dark detectors so the doctor detectors is not actually detectors to receive signal so we expect not to see anything here but we see something it meaning that we

have some leaking power which basically degrade our sensitivity to have any effect on r and this is you know what we start to diagnose so this happened in 2022 season at South Pole then we get back to Caltech again start to do some diagnostic tests at Caltech this is Caltech test bed by basically diagnosing where is the streaking power come from and to do that we

both hear our detectors that cool down to 150 millikelvin and the start to put here a range of different filters with different cutoff to diagnose where is this leaking power come from and then we realize the solution which is the solution here we improve we need to improve our filter configuration at the South Pole and this is why we went again in 2022 season to do

this upgrade which is installing a new filter which is successfully eliminate this power down which is what we what we want so this is the 220 season and then we you know we just eliminated out and this is we also play replace you know as Jamie just mentioned we were like five four people and this is you know the four people that were at softball yeah

and this is you know the detector camera shows that all the frequency band of the of you know for looking at the sky so after we implement this new filter configuration we can say that this upgrade we look at the sensitivity again and we found that this upgrade really improves the receiver sensitivity and the depths to the close uh to the design level so we succeeded

to do that in the second season and then you now uh and then after that we loaded after we did this upgrade in the second season we loaded the telescope back in the mound you can see that this is this is inside our lab after we load our telescope just you know just seeing the scanning of South Pole uh you know going this is my colleagues

and yeah and this is this is really cool video at the top of the telescope so we can see that we're going up I actually took these videos for uh you know for my kids and also for myself and also because uh a lot of people are interested to see what's going on at South Pole so you can see that you know we loaded this is

our telescope and as I was mentioning we have four receivers and this is the first one that we deployed this year this was uh the old kick that we're gonna we replaced one this year and two at the following years so this is the new telescope that's looking at the sky and you can see that we just like checking a few stuff at the at the

top um yeah it was really cool and then after we loaded it we just start to do some measurement on the Sky by basically to see how this telescope here we're gonna see at the sky so we measure some beautiful beams in the sky which me which is basically validated our Optics design and at the same time we do some measurement of the noise to see

that we are background noise dominated and this is what we can see here in this green region that the sensitivity now is agree well with the theoretical calculation so now we say that okay we succeeded to do this it's time to get back home and this is uh the end of season uh you know picture here showing at the end and this is like funny picture

so one of my colleagues pretending that he wasn't he was drinking gas like but no guys of course it was just funny moments uh yeah at the top of the telescope yeah this would at the end of the season and you can see that now uh it's it's scanning everywhere um yeah so can I ask what is this this is not the sun this is the

Moon uh yes this is the moon so because we do our observation during the winter and the winter just like six or eight months of darkness and this is just the moon no sun just 24 hours of daylight for four months or six months and 24 hour of darkness in the other six months the temperature here reached like minus 50 something but he is like the

lowest I see it was like minus 92 degrees Celsius which is is deadly level yeah so uh yeah exactly but after we after we finish in February we left to get back to America again and then the Station closed because no you know the station is not accessible during the winter because no you know no blink can fly in this cold temperature so once it's closed

it's done and um this is like you know at the summary of what we did uh here which is like the bicep array generally is searching for the inflation and this is uh searching for the inflation of tissue waves it was high sensitivity level and the measurement of such signal is very very important in the fundamental physics because it can provide a lot of information about

the alien universe so this uh so the news is this year we deployed the second receiver at 150 gigahertz and this is part of my team and next year we're going to deploy the second one and 222.70 and then we have one more like maybe the following year to have fully deployed uh receiver like very soon so now we come to we finish the technical part

now to come to the fun part so while we while we while we are achieving our science goal we got some fun time as a fun time means that we are exploring the South Pole it was an exceptional experience so I recorded a lot of videos so before I go to the South Pole I bought a new phone it was high memory just to be ready

to go to our pool especially in the second season because we you know we blend to stay like four months so first I will show this this is a really cool picture for one reason the the in 2020 when I went to the South Pole my colleagues told me that you know Ahmad uh do you realize that you are the first Egyptian scientist who come to

the station and I didn't believe them and then they say no it might it might be possible and then the South Pole station manager brented out this flag for me just to take picture here but the second season I brought my own flag which is like flying here uh all the way uh yeah and it was really cool because I was the only Egyptian and the

Arabian in the station back then and when I start to like send the messages to people saying that you know real do you guys realize that there is a place on Earth that has 24 hours of sunlight no one no one believes that literally until I just take videos and photo to show them there is a place like this and you can see that also in

this video when I was trying to take a picture it was very very cold minus 50 something and I I asked if my friend is the station if someone can take me a picture and they said oh man you you the Egyptian built the Pyramid so they can go now so I went by myself and that was I was having hard time to basically adjust the

the you know just to the South Pole sign with the sun Hollow and it was uh was uh you know it was here I was the flag Egyptian flag the second thing was which is really cool is we got some time uh to deliver a lot of educational events to schools to steam schools around the world so Iris I literally received lots of invitation to make

videos to school one of you know the first one coming from my home country Egypt so this is one of the school here this is me I took some you know through selfie and this is the Egyptian flag and this is American flag and I just think Sylvia was this people so I was like you know we had a meeting from with this school you know

from different area in the wallet and like you know Egypt and just you know many branches in other areas and we just you know was talking about the science early Universe South Pole our experiment which is really cool and you know the First videos that I delivered it reached to millions of views really I I didn't believe that until I see it but because no one

you know you know believes you know it's it's South Pole so and uh and when I get back actually and oh yeah I also recorded this video uh which was was listening by you know my friends you know primary secondary school almost uh and then I went also to Hamilton school as well as you can see that this is my son Noah and I was delivering

you know some you know some cool videos about South Pole and you know science were doing and some penguins maybe because this interests people especially kids so we did we did a lot of fun stuff at Paul you know this is just short from what we did but you know we got a lot of videos and and we also in Antarctica got some few funny moments

we got some hiking because we quarantined in in in mcmordo station for like two weeks and we just do some hiking and you know we got some fun time here around uh in in mcmordo and also mcmordo you can discover the deep ocean which is something so this is like a tube 12 meter down and this is me actually here you see this this is me

just go all the way down into here which is like a glass you can see you know underneath underneath this sick uh layer of is and you can go all the way down so you can see some jellyfishes maybe some like seals just going around which is really cool and also in in mcmordi you can see some penguins and this is uh you know robots code

the first house in in mcmordo and when you when we go inside here with my colleague James from Harvard University team we visited this house you know what it is this is the leftover food has 120 years old and the almost it preserved as it is it preserves additives and you know the cold temperature you feel like it's you know I you know you feel like

it's a fresh food you know it's it's like 120 years old uh and also we see some biscuits and other food you know inside here uh which is really cool and also at the South Pole you can do this really cool stuff [Laughter] uh yeah you can see the sun uh Sun dog here and you can see because it was just really cold and actually you

can see here the sun dog but I I realize that you know if you can see this um this is like a video showing that it's real it's not like a camera reflection or something and we'll see we see the double Sundog uh which is really cool and that's how spool you can enjoy is a Midnight Sun which is like this is like 12 and you

can see the sun 24 hours which is also uh something new I never seen in my life and also you can discover the underneath tunnel which I see recorded like minus 60 something degrees Celsius underneath here it is also called uh yeah and finally not finally you can have some beautiful moments at the South Pole here with my beautiful family uh you know not Aaron and

Noah and my wife she's here now uh yes and then you know it's really cool that uh to have some family moments and then in the winter you can see this um you see this beautiful this is a South Pole telescope and this is our telescope biceps three which is really cool during the winter observation you can see almost like you know just it's really magical

yeah yeah it's a I'm trying to summarize as much as I can uh yes and then I finally would like to um yeah at the end here to just put it in the memory of my co-advisor Jacob vanziel who passed away a few years ago he's really a great friend uh this is I took this picture during the physics and remote sensing class at Caltech uh

such I'm just sending a message to his family that he is really missed uh yeah and then I would like again to acknowledge uh my team members in the CMB lab leading by my advisor and bicycle collaboration team members and The Graduate Office Natalie and Doug isn't just uh you know all the team and also the ever hard talk series committee and the international student office

and hopefully but firstly my family for doing this so yeah uh this thank you so much yeah this is uh this is a bingoons I took this picture in mcmordo I I stuck in mcmordo for one week because it's really hard to find a good wizard so sometime go outside and see what we can see so I see this being going that I say hi yeah

any questions that's actually what you see yeah this is actually yes this is actually what we see from my friends I did I wasn't I wasn't there during the winter but my friends told me this is actually what what they saw uh you know in in reality is that uh it's a pure pure environment at South Pole which you can see all of this do you

get any interference uh not not for a moment and the reason is you know the South Pole is like uh we call it dark sectors which mean that we don't have any interference from anywhere around us you know we don't have RFI you know anything like this at all at South Pole and we also have some sensitive to detectives if exist but we don't have you

know even at South Pole you know there is no Wi-fi you know it's like it's called Dark Sector which means like no it's like viewer environment uh which is really cool yes any questions yes um can you maybe like talk a little bit about the timeline of how your team decides on like the design strategy and if something goes awry and there's like a small cheap

thing like what does that process look like for you uh personally and then as a team like that's you know are there different regulations or like what's that process look like you mean if we yeah you mean if we see any like troubling problem or something yeah for example it's like one of your services is not doing the type of detention that you wanted to do

yes that's that's uh that's a good question uh so we basically every year we go to the South Pole during the summer time to do upgrades to one of the upgrade that you know you know is like troubleshooting if the receiver is working and then diagnose if we have any problem like that we always if we can fix it at pole it can be done if

it can't we get back and do all the you know what we need like for example the upgrades that we did in the first season that we after we closed uh up our telescope and we bought it in the mountain we see these problems but we cannot you know you know just do that at all so we get back in the second season to upgrade this

and the improve sensitivity which is something is really cool because it's like you know support logistic it's easy uh to access at South Pole yeah every yes go ahead aluminum foil what was the reason for that uh yeah the the aluminum foil is just reflect any yeah we cover we bought some like tapes uh you know around to cover any Gap to go inside the Chrysler

because we have some readout Electronics yeah this is something that I didn't show but we saw this RFI effect imagine that we have picking any signal by our electronics and we can see it as a noise in the detective time stream how we can fix that so we can fix it by closing all the gaps to minimize that but there is something around the around the

detector it's called but we bought not foil it's just a Miler to minimize the heat transfer between the stages so there is we we are you know we have different things to put around here just to you know according to what we what you need to improve or what we need to protect from in our telescope we have magnetic Shield as well if you notice there

is something in my opium shielding around to to prevent any you know any magnet to go inside as well and also we have shielded the squids squid is like our readout oh like that used to amplify and Multiplex the signal we already like shielded very well because it's very sensitive to this magnetic field as well if it exists so yeah we you know we we are

fully protective almost of all yes yes is supposed to look in terms of detection are there like any known interference ways that you could induce and like look at the Delta or um where you can look at the difference like pretty imposed if your parents will look that noise me too high uh so you mean if you mean if any interference that can contaminate the B

mode that's what you mean I guess yes things that they want to appearance or perturbation and look at creating those motivations for your detection you know how the Evo you're anticipating it to look or detect can you induce some known interference pattern yeah but we already have interference I mean like contaminations already which is coming from the polarized foreground as I mentioned or the lensing B

mode so but and this is actually the reason this is the mean two reasons that prevent us from C is the ultimate detection which is this interference and that's why we do all of this to go deeply and characterize it and just remove it uh yeah it's it's it's kind of like you know we have enough orange that we are addressing in our our experiment I'm

not sure if this answer a question but yeah okay yeah go ahead is it only protecting CMD or will you use it to detect other interesting Cosmic and Interstellar phenomena yeah for now it's fully designed to to basically just observe the angular scale for the B mode detection the signature of inflation which is as I just mentioned it would have imprinted the CMB uh this is

the mean that you know we just want to look deeply in something but we didn't use it for any other science application we just like targeting one thing that we are chasing as I mentioned like wild goose chase and once we come closer it's going down it's upper bound uh you know and which is really hard but I think that one day I think we we

will detect it but we'll see oh you know it's not true yet but but at least what we the result that we have helped us to understand you know how the inflation happened there is a lot of inflation models the inflation model used to describe the scenarios in the first few moments of the universe so our latest result ruled out with some of the popular inflation

model by even even better in lower bound uh sorry upper Bound for the the inflation gravitational waves things that like R which is a tensor scalar issue should less than 0.0 C6 which is according to Big 18 data and we're just going down and down as I show in the table until we'll see yeah just any questions thank you