From the Big Bang to Intelligent Life
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Roll formingForgingCosmic microwave background radiationBig BangUniverseCrystal structureSmoot, GeorgeLecture/Conference
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UniverseMagnetic momentWedge (mechanical device)Cell (biology)StarGalaxyHubble Space TelescopeCardinal directionEuropa (record label)MetreOpticsWeaponSnowAstronomerTARGET2SatelliteLaserPatch antennaVisibilityMinuteOrbitPlain bearingSpacecraftApparent magnitudeSensorLaserForceCrystal structurePair productionGravitational singularityMaterialMinuteUniverseSolar SystemAdaptive opticsCometGround (electricity)GalaxyYearFinger protocolStarInfraredDark matterMeasurementStarShadowAbsorbanceBook coverWater vaporAngeregter ZustandKopfstützeSpare partNeutrinoSpaceflightBook designPlanetEffects unitOrbitStellar atmosphereHot workingPaperFlavour (particle physics)Buick CenturyCamera lensFACTS (newspaper)SensorRRS DiscoveryVisible spectrumElectric beaconFormation flyingDVD playerLaserRail transport operationsMarch (territory)SatelliteString theorySkyAstronomerLaserBig BangColorfulnessCrystal structureAtmosphere of EarthSheet metalInfrarotastronomieCluster (physics)
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Big BangUniverseRutschungEnergy levelNoise figureLecture/ConferenceMeeting/Interview
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Model buildingFlatcarThursdayRutschungYearMeasurementNegativer WiderstandSpare partTypesettingGreen politicsMicrowaveScale (map)FeldnebelRadiationUniverseBig BangGround stateMeasuring instrumentDensityVideoSupernovaFinger protocolCrystal structureBaryonAcousticsDiagram
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Power (physics)Energy levelNeutrinoRRS DiscoveryGalaxyVisible spectrumQuantum fluctuationYearMicrowavePerturbation theoryAudio frequencyIntensity (physics)TemperatureBand gapModel buildingLightPower (physics)Mode of transportSatelliteRemotely operated underwater vehicleMeasurementCosmic microwave background radiationSoundGravitational lensUniverseDoorbellSpare partAM-Herculis-SternRing (jewellery)MassLecture/Conference
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Angeregter ZustandEnergy levelRRS DiscoveryBird vocalizationYearSolidMode of transportUniverseCondensed matter physicsStarBig BangGalaxyScale (map)Fundamental frequencyStationerySpare partLecture/ConferenceMeeting/Interview
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NeutrinoCosmic microwave background radiationAmplitudeMoore's lawSource (album)Energy levelPower (physics)TelephoneProgressive lensBird vocalizationNeutrinoTemperatureWater vaporScatteringLecture/Conference
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Order and disorder (physics)Quantum fluctuationFuelScale (map)Power (physics)Multistage rocketField strengthModel buildingCar tuningSpare partSatelliteEnergy levelMicrowaveLecture/ConferenceMeeting/Interview
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Dark matterBig BangCrystal structureBlack holeUniverseSupernovaStarStarGalaxyYearRestkernElectric power distributionFormation flyingHose couplingLastLecture/Conference
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RRS DiscoveryPattern (sewing)SkyCosmic microwave background radiationPlanck unitsKosmischer StaubTiefdruckgebietGalaxyAudio frequencyOrder and disorder (physics)Mode of transportYearScale (map)Spare partLimiterMeasurementAstronomisches FensterLecture/ConferenceMeeting/Interview
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Captain's gigMeasurementLecture/Conference
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Line-of-sight propagationUniverseFinger protocolFACTS (newspaper)Amplitude-shift keyingNeutrinoStormSigmaLecture/ConferenceMeeting/Interview
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Mode of transportDirect currentControl panel (engineering)Dark matterLoudspeakerOrder and disorder (physics)LimiterLecture/ConferenceMeeting/Interview
Transcript: English(auto-generated)
00:14
from Big Bang to intelligent life, a really interesting topic about the structure and evolution of the universe.
00:22
And this Agora talk will be by the two winners of the 2006 Nobel Prize. They got it for showing that the microwave background has the black body form and it's anisotropic, which is very important for structure formation, for instance.
00:42
So we will start by letting John Mather show a few slides. Then we will go to George Smoot. And at the end, there will be plenty of time for questions. So please, John, show your talk. Thank you for the introduction. Let me stand up here so I can see you better.
01:02
I wanted to talk about the steps that lead from the Big Bang to us. And of course, we don't know them all. So a summary of the early universe that we have measured. It was very hot and very compressed in the beginning. There is probably no center and no edge. People talk about a singularity, but a singularity is not a place
01:22
where things are infinite. A singularity is a place where things are unlimited. Unlimited is not exactly the same as what people think of as infinity. There is probably no first moment, although you probably have heard that there was a first moment. There is no instant of creation. It is not a giant firecracker.
01:41
So there probably is no end. So that's the summary. So this is what we did with George and me and our team at Goddard Space Flight Center and many other places. We measured the spectrum of the Big Bang to see if does it have the right color. And yes, it does.
02:01
It's called a black body spectrum. And we measured to make a map of the sky to see does it have hot and cold spots. And yes, it does. And we are here because of those spots. People don't know that those spots are so important, but they tell us, number one, there was dark matter in the early universe. Number two, the dark matter was much more abundant than the ordinary matter.
02:20
And number three, gravitation acting on that matter was able to stop the expansion of material locally, turn it around and turn it back into galaxies and stars. So we are here because of those spots. Now, if you knew what made those spots, that would be another step. When we do know that, then somebody will get a Nobel Prize for that.
02:40
So this is the next map that we made. This is from the WMAP team. And they made a much better map than we had made. So that was really nice confirmation. And we were very pleased to see that all the measurements that we got with the COBE mission were correct. They did it better and they got the same answer, but much more detailed. So from this map, you can compute many more things.
03:02
The details of how much dark matter is there, dark energy, cosmic number of neutrino flavors and all kinds of other things you can get from this. And the statistics of this map are matched within a few percent by the few numbers that we have to describe cosmology. So that's a pretty astonishing story to be able to tell you.
03:20
We have now a movie, which I don't know if you can even see it in here because it's pretty light, but at any rate, the movie shows the effect of gravity acting on those hot and cold spots. So the computer people have taken a box of universe, filled it up with random numbers, similar to the ones that we measured with the COBE satellite and allowed gravity to work.
03:44
So this is the effect of gravity operating on those random numbers. And what it produces is the galaxies like ours. And we know from the movie and actually now from observations as well, that the universe is divided into huge empty spaces, that the galaxies are arranged in strings
04:02
and clusters and sheets. So the structure of the universe that we started to measure with the COBE is much more complicated than you could possibly imagine. And it is beautiful. There in this movie about a few billion years in, you're starting to see cosmic explosions, which is part of the story of disasters
04:22
that have been responsible for our existence. You know, in Greek disaster means bad stars. So bad luck everywhere, but good luck for us. So I think because time is short, I'll skip the rest of the movie and see if I can jump to the next movie. This is another story of bad stars.
04:41
This is a simulation of the early solar system when the hypothesis is that it could be unstable. So here are the four giant planets in their orbits running around in more or less circles, surrounded by comets and asteroids left over from the formation of the solar system. And you will see after about a billion years, it becomes unstable.
05:01
So this is another part of our story of the early universe. Everything is unstable if you wait a while. And this is just gravity running along like gravity does. And you see it's possible for the planets to interchange their orbits, to exchange gravitational energy with each other. And for a few hundred million years,
05:21
for those comets and asteroids to bombard the earth possibly bringing in the water that made it possible for life to exist on earth. So that's a pretty amazing story. Yet another disaster, catastrophic disaster in our history. So what happens next? Well, would you like to know?
05:42
Well, we build telescopes to find out. So this is a cover of a new book by Neil deGrasse Tyson and Avis Lang. And you see the title there says Accessory to War. This is a reminder that although we think pure science is pure, that it really isn't. There's no avoiding the fact that what scientists invent gets used by military purposes.
06:04
And when Galileo was selling telescopes, he sold them to people who had military purposes as well. So it's been going on for at least four centuries that scientists were working with military people. And of course, this is why when I want to have NASA buy a telescope from a big company,
06:20
the company says, yes, I can build you one of those. They already built them for other people. So we are actually a very small part of the world wide space budget at NASA, but we have time and we have ideas and we will be able to continue to make extraordinary discoveries because this is actually a small amount of money
06:42
compared with what we do in the world. So this is what the Webb telescope looks like. I'm not gonna spend much time with it just to give you a sketch. There is the giant golden hexagon. It will be launched in a year and a half in March of 2021. And it will open up infrared astronomy to observers everywhere.
07:00
If you're an astronomer anywhere in the world, you can send us proposals to use this telescope. So it does infrared astronomy, which you cannot do from the ground because the air is opaque and it glows. So the telescope is going to be out there and it will be cold so it doesn't emit its own infrared light. In international partnership involving Europe and Canada and the United States,
07:23
future projects I think will involve many more countries. Jumping ahead just to remember that those are not the only telescopes we have. We build even bigger telescopes on the ground. These are three gigantic telescopes that are in preparation now. All of them have been started. The biggest one is European and is going to be built,
07:42
is being built in Chile in South America. And when we finally get to where we can get the full angular resolution to which we are entitled by such a large telescope, it will be so much better than what we've ever had before that you will be stunned. So much more astronomy is coming to you. It will be continuing to be an exciting subject
08:01
for decades to come, maybe centuries. So how are you going to do this? There's something called adaptive optics. If the atmosphere of the earth is shimmering and dancing so you get a blurry picture. So however, we've learned how to compensate for that. We've learned how to do it so well that when you go to your eye doctor, the eye doctor does it too.
08:22
They can look through the lens of your own eye with adaptive optics to get a better picture. And if you are really a serious person and you're a football player and you really need to have the very best possible eyesight, they can fix your eye based on the same mathematics. You can have adaptive optics in your own eye.
08:41
It's great. So when you can do that, well, maybe you should have a beacon in space to focus on. So I'm now working this new idea called an orbiting laser beacon. We would like to fly satellites that have lasers shining down on the ground. So you can focus the telescope on whatever you like. It's not hard, but we haven't done it yet.
09:03
Even more wild idea I'm currently working on. Let's imagine putting up a star shade to cast a shadow of a star onto a telescope on the ground. And then we'd be able to see planets orbiting another star way out there. Using these giant telescopes I just showed you, we could see an earth way out there in one minute.
09:22
So it's not so hard, but it's still really hard. So just to wrap up, I want to tell you about something that caught my eye this year, a completely different thing. I wanted to mention that since we're talking about the origins of life, let's talk about the physical description of that. The physical foundations of biological complexity,
09:42
I really recommend this paper to you. I really don't have time to go through that because we want to have your questions, but I want to commend you the idea of this new work. It's called self-organized criticality and it's a multi-scale description of the physics
10:01
and the mathematics of living systems. So from there, I have no idea what you will do, but this is the next step, I think, in trying to understand the origin of life and the way that we here have arrived on earth. So this is hard work, but let's see, there's a description of how that works,
10:20
but I want to wrap up with what is success. You may have heard this one, success consists of going from failure to failure without loss of enthusiasm, which means to me to be a very apt description of science. So thank you. And then we'll have Georges and then we'll have questions.
10:44
Thank you, so let's hear Georges' take on this, on the title, From the Big Bang to Intelligent Life. So I'm gonna try and keep mine short because I know you guys are gonna have a lot of great questions, but I wanted to stress a couple things. If you've got my slides, they might have my slides.
11:02
And I was asked by one of the students yesterday to please explain at the beginning what this is all about. And that's kind of hard. You saw John run through this whole thing, because we're only talking about the universe from the Big Bang through intelligent life. And the point here, if I ever get the slides,
11:20
is that in fact, it's just like physics. You better get your first level of physics right before you go to the next level of physics. And we must get our understanding of the early universe very right before you move on to the more complex understanding in terms of what's going on. So I do have slides, and that's a good thing,
11:42
and I'll just figure if I can go forward or backwards. So I'm gonna talk about what's our big picture of what's going on, and then why do we actually have very high confidence that we're not far off. And then we can go forward to try and say,
12:00
well, how do the stars and galaxies form? How do planets form? Then how does life, and then eventually intelligent life. So we had some simple concepts. This is from 30 years ago. We had the idea there was somehow a beginning of time. There was some chaotic space-time. We had something called inflation,
12:20
which we think is how we got our big space-time. And then suddenly we see the cosmic microwave background, and suddenly we see mature galaxies and life and everything else. So that's the kind of big picture of what it is we're trying to do. We're trying to trace all that out. And so how do we do it? Well, we have observational support. You hear this in some of the stuff,
12:41
and Bart Macdonald is here. He covered some of the stuff at the beginning, but I'm gonna do one of the slides that way. Why do we have confidence in what's going on? We have a set of observations from looking at the cosmic microwave background, which tells us the universe is very near to flat. That's this line, this line here. And we have the supernova observations
13:01
that tell us the universe is accelerating in its expansion. And we have large-scale structure. Here are the baryon acoustic oscillations here in green, or galaxy clusters in green. And all of them overlap at a place where the total density of the universe is one, and the universe is flat geometry. And it's about 30% total matter,
13:21
and about 70% what we call dark energy, whatever is causing the inflation. It's causing also something else. So the data points are fitting together. And in fact, we only argue about small deviations now. Everybody agrees that everything is agreeing and that kind of stuff. And so let me do a little bit of history. So the CMBE was actually discovered now 55 years ago
13:42
by Pisius and Wilson. And you can see their data point right there. And you see this line through that and a bunch of other data points, some from my group, and then tremendously good measurements from the FIRAS on COBE, which is, John was the PI for that part of the instrument
14:01
and the project scientist. And that was 30 years ago. Doesn't seem that long, but it was 30 years ago. And that is really evident that the early universe was in complete thermal equilibrium and well-exposed, and that this radiation really came from the beginning universe.
14:21
A year later, we announced that though the universe is appearing to be extremely isotropic, when you look on the finer scale, where there are variations that are part of 100,000. And those are variations that we talk about that create the large scale structure. And what we're seeing is this is the ground state
14:41
and what those things are, acoustic oscillations that let us look back into the early universe. And we are recapitulating all of physics in the history of the universe. And you can see on here, the LHC energy scale, you can see back all the way towards the Big Bang. And we're having to recapitulate all that. And we're putting this stuff in and calculating,
15:01
and we see that we find things, we observe things to an accuracy of about 1%. But I'll tell you an example about what we observe. So one more thing I wanted to say about this, so go back. That when you look at the cosmic microwave background, frequency spectrum, its intensity versus its frequency or wavelength,
15:23
there's one parameter, that is the temperature of the universe. You get one point, it should predict the whole curve. If it says it hasn't got one point, they predict the whole curve and you can see how well it's completed in that way. When you go look at the cosmic microwave background and map its intensity, and then go and look at what the fluctuations are
15:42
as a function of angular scale, you see these wiggles and bumps, right? These are the sound waves in the early universe. And if you hear like a bell ring or a fluid slosh, you can tell what it's made out of, you can tell what the speed of sound is. There are certain standing waves. And so that means we can fit to six parameters
16:02
and we can measure those parameters with a very high level of accuracy. And that level is quite precise. That's roughly 1% now on things like how much is matter, how much is dark energy, how much is the various aspects. And that's very critical.
16:20
And so now I'm gonna say from theory, you can take a cosmological model and you can predict what the angular power spectrum is of the temperature, but also you can predict there should be polarization. And if you say there are scalar fluctuations in the early universe, you predict the power spectrum, the four of them that are shown here. I don't know how to point very well,
16:41
but well, I kind of can point. So over here are the scalar perturbations and the temperature temperature, the temperature E mode polarization, that is what you get from scalars, the E mode curves, and then the gravitational lensing of the E modes
17:00
to turn them into B modes. Those are all straight predictions. Once you have one curve or you've picked one cosmology, those just fall out. So if you measure those curves, which are shown measured over here precisely, they all better fall on the same line or you've got something wrong about your cosmology. But if they all fall on the same lines,
17:21
then you have your cosmology very accurate in terms of your predictions. Now, the other thing that's predicted is something that I got involved in quite early is that there should be not only scalar modes, but there should be tensor modes. Those are the fluctuations in the metric and the spatial part. And we don't know what that should be.
17:42
And so Douglas Scott and I, when we did this review, we just put them in at 10% level and there they are, right? A great discovery would be to find that and fill those things out and see if it's the same thing. Well, we may or may not. We may be lucky and nature may show this to us or we may be unlucky and it's just below what we can do
18:00
because the galaxy and other galaxies get in our way. The next five years will tell that. So there will be CMB measurements cleaning up these bands here and there will be a Japanese satellite light bird designed by JAXA. And if they're lucky, they'll see a little tiny bump there. And that will be the B modes.
18:23
If we're unlucky, we won't see anything. And so, but we're making more and more precise measurements. The temperature provided us one unit of information about everything. The polarization gives us two more units each. From those we'll know, if we happen to see the B mode, we'll have everything more precise.
18:41
The reason I'm wasting time doing this is to tell you, you can't just arbitrarily stuck stuff in cosmology anymore. Cosmology is getting to be more tightly knit. It's very hard to make adjustments. You know, changing the mass of the neutrinos is a problem, right? And so it's an issue. All right, so I want to finish up
19:00
and basically say, we're telling what's going on over all these epochs. And from those, we're able to predict so far everything we reserve, except in Adam Reese's talk, he'll say there's one little thing that's bothering us, one little crowd on the horizon. But we'll see whether that goes away or whether that comes out okay. So I want to stop at this point and answer questions
19:21
because I think it's more important to hear what you guys have to say than it is to tell you more about this kind of stuff. Okay, so Lars and John.
19:40
Okay, so I'm sure there are lots and lots of questions. So where to start, perhaps there. And please use your loud voice. Or the microphone. Or the microphone, yeah. If it's nearby. And maybe you could even step forward. I'm going to find my best. Yeah. One call.
20:01
Ah. We were hoping to find some. I think we have two examples here. It's a big question that everyone is interested in. And as you can see, John is interested in it. That's why he's designing that special sunshade. And if you guys are smart physicists,
20:20
you'll realize it has this sun power thing because you want to avoid the fraction coming back in with your star or coulter. We want to show, and we expect that people will do that in the next 20 years that there's life on other planets. But you won't know there's life for sure until you answer the question you guys really want to know, which is is there intelligent life in the universe?
20:40
And that's, you know, that's a big question. May not be solved in your lifetime. I think that's right. I put it in the title because I thought you'd like to hear about it. And I wish I knew the answer. So I think this is one of the most exciting things we could be working on as scientists is how does that happen?
21:01
Okay, yes, there.
21:36
You want me to take this one? Yeah, you try that one. Yeah, okay. So right from the very beginning times of COBE,
21:43
we've been wondering are those spots a random Gaussian field or is there something unique and unusual there? And so very quickly I got a Spanish graduate student who came and worked with me, Laura Keown, and we did a study and we saw, yeah, it's interesting. There's one that's a little whatever it is.
22:01
And then later on you'll hear about the axis of evil or whatever it is. You know, there's certain various things that go on. And the problem is the plane of our galaxy hides things a little bit. So there's always room, there's always stuff at the two, three sigma level, right? That's why high energies, as I say, we don't look at anything below five sigma. And in the universe we don't have as many observations
22:22
as many, we can't be quite as distinctive. However, you're referring to a study that was done that I think that refers to an idea that Roger Penrose have and I kick myself for that because I did have a graduate student who was working on this and did her thesis on it.
22:41
And then also with Alexi Starvinsky, we did it, which is to see what the size of the universe was because the universe doesn't have to be infinite. It could be like the video games. This edge is identified with that edge. So the spaceship goes like that. You know, it goes across your view and then suddenly appears on each other. And so you can show the size of the universe
23:01
is quite large. Penrose had the idea that you could identify time, which is pretty obvious, you know, once he said it. And so then if you have explosions or other things happen in the early universe, it makes a sphere and it intersects your line of view as a nice big circle, which will be whatever it is. And he got some colleagues who did an analysis.
23:23
I think these are the people you're referring to. And they found what they thought were features. Everyone else who've looked at that have found not the features there. And so it's interesting. And John Levin wrote a whole book about how the universe got its spots, considering all the possible configurations and things.
23:40
So far, the universe looks incredibly isotropic in terms of not having preferred access or whatever. But we only got one universe and the statistics get really low when you get to this very big angular scale. So it's tricky. Let's take one from there.
24:01
Coming back to life, I have a question.
24:34
To the high-risk, we can jumpstart life there. Just a theoretical question.
24:41
Not that we would do it, but we thought so. Yeah, so the question is, could we send our kind of life to try out another environment? And of course we could try it. There actually is an international treaty that says, do not do that. Right. Because, yeah, we want to find out first if it's alive.
25:01
Before we go put our own kind of life there. So my feeling has been all along that life is a kind of thermodynamic imperative. People thought years ago that life must be extremely unlikely because especially rare coincidence would have to occur for particular molecules to happen.
25:20
We're not finding that anymore. We're finding a remarkable number of ways and pathways for molecules to self-replicate. So we no longer think it's so unlikely. So my guess would be if life can exist there, then it already does. So that's a really important thing to find out. Similarly on other places, there's another satellite of Saturn called Titan,
25:42
which is cold, but has hydrocarbon rain and lakes and rivers, and it's over ice. Ice is surface. And then under that, there might be a liquid ocean of water. So this is another astonishing place to think about as a possible location of life. And it would be quite different from ours.
26:00
So I think we should look there. And you may have seen that we're just, at NASA announced that we're going to send a helicopter to fly around on Titan. It's an astonishing little thing. It's a little like a drone, but it has a nuclear power source so it can fly even way out there. So we're gonna go exploring on Titan.
26:21
Okay, you?
26:54
All right, you want me to try this one? Yeah, try that one. Okay, so actually I was careful not to say that we understood most of the universe.
27:01
I said we understood it from this point I marked on the plot, not the part where it's the chaotic space time and pre-Big Bang. And we believe that something like inflation happened, and we can calculate that, but it doesn't mean we're right that we can.
27:20
And I was very excited three years ago when the BICEP2 people claimed to have seen the B modes because that would imply we understood a lot because that would say the energy scale of inflation was the grand unified station. But it'd also tell you that quantum field theory was probably correct back that far in time.
27:40
Alas, it's not true yet. And it won't be true until some lower level. So we do not know, we don't know what the laws of physics are before that time. That's what I was saying. In that plot that was up there, we're recapitulating all the physics that we know, and we guess at some. And there is still more things to learn
28:03
about the beginning of the universe, and then there's more things to learn about what we used to call condensed matter physics, well, solid state then became condensed matter, but now it's like multi-particle systems. As you start forming galaxies and stars
28:20
and more complex things, and eventually more complex molecules in life and so forth, that's a place where there is room left for surprises. We don't think there's necessarily new, basic fundamental physics, but there's new physics in those kind of things, the same way you see in very large collective states
28:42
in condensed matter physics. There are new properties emerge in those kind of situations. So there is plenty of room left for discoveries. What I'm saying is I don't think you're gonna find any more continents on the Earth. I don't think you're gonna find any more big pieces between somewhere near the end of inflation
29:01
and much later until you have planets and you're worried about how did life start. One more question from that half, yes, you.
29:21
Oh, goodness, mapping the neutrino background. I actually had a telephone call from Joe Weber a long time ago. He said that he knew how to do it, but I thought he was not right. So the neutrinos are just not that easy to see. We need 50,000 tons of water to see something happen.
29:42
And so once in a while we get lucky and we have a new even better idea. As you know, the Antarctic ice sheet is now instrumented so we pick up things and we actually have found one neutrino whose source we could detect and associate with an object way out there. That's a spectacular accomplishment. So but the cosmic neutrino C has a temperature of 2.2 Kelvin.
30:03
So nobody has a way that I've ever heard of to map that. We deduce that it must exist and that's as far as we've gotten. We have good evidence from the spots on the CMB map that neutrinos participate and they control things. But the details of exactly what they're doing,
30:22
no, we can't get that. So almost every physicist that's ever thought about this problem has tried to calculate how to do it and they all fall or there's a bang, it's too short. I see my neutrino colleagues there say yes, we've figured out how to do that. You have to do coherent nuclear scattering. You have to do a lot of stuff and it's just really low level.
30:42
And I'm not saying we won't eventually get there because those plots that I showed you, it started at microkelvins for the amplitude or power squared down to nanokelvins. That is really impressive progress over the last 30 years. We're on the Moore's law. So eventually things can happen.
31:02
Okay, so we have a question from here.
32:01
Lower. Yeah. Okay, so there kind of was a question in there which is how can you be of inflation when the observations are squashing inflation down like crazy? And the answer is you need some kind of fine tuning
32:23
to make the potential be so flat so that you get way more than the 70 E-foldings in terms of it or you have to get a lot of that or you have to imagine that there's two levels of inflation. The thing that was interesting about Bicept was it implied that it was large scale inflation.
32:40
That is the fuel strength of inflation was up in the Planck scale and you were rolling down this hill and it was getting flatter and when it came in the last part that came in the horizon, that part was at the level that was low enough in order to do it. Because we're looking at results that give us inflation so flat, you have to be either more careful in tuning
33:03
or you have to think that you had multi-stage inflation, right? There are some models of physics and clemency. Right, you read double or triple. There can be a whole waterfall of inflation. There are many ideas. There's not much observations. There's plenty left to do to learn about how the universe began.
33:24
Let me add that when inflation was first suggested, we were already building the COBE satellite and the science team thought, well, that's fun but it's probably not gonna be testable and so we were quite surprised when later on there were a few predictions that could be tested against the detailed spots on the microwave map
33:40
when we got better angular resolution. So there's a thing called a slope or a power, there's a power law that describes the fluctuations and originally people thought, well, the power law should be minus one but then inflation came along and said, well, maybe it should be minus 0.97 and it just about is which is a startling result. I thought there's, when we first heard about it,
34:02
there's nothing they could possibly predict that we could ever measure but it wasn't true. We could measure something. Okay, so we have a question from way back then, a woman, yeah? Oh my goodness.
34:21
Well, what we're hoping to do with the web about the early universe is to see the first stars and galaxies growing. So it is calculated that if a supernova blows up at a redshift of about 20, we should be able to see one individual star back within like a hundred million years of the Big Bang itself. That's pretty spectacular kind of test.
34:43
We should be able to test that movie that I show you which calculate says, assume we know something, does it look like the universe that we see? Do the galaxies grow? Do the black holes grow? So we don't know yet whether the black holes are formed by galaxies or whether the black holes are the nuclei for galaxies to grow on.
35:02
So we also don't know how the black holes grow so large and all of these things will be topics for testing our ideas of the early universe. We should be able to see some better information about the dark matter distribution also as it controls the formation of those earliest galaxies. The story that we tell
35:20
is that the dark matter formed structures first and because the dark matter was able to move while it was still before the universe was neutralized and before the decoupling. So there are structures in the dark matter that then attract ordinary matter into them. So we'll be able to test that whole story when we couldn't look much farther back into time
35:41
and much closer to the formation of the first objects. Okay, a couple of last questions. Let's see, I think, yeah, take for that side you.
36:04
Okay, first of all, it is not clear that bicep was erroneous. Their strong claim was erroneous. They chose from our Planck data, they chose a part of the sky that was very low dust but it also happened to be a place
36:20
where the magnetic field of the galaxy was fairly significantly organized and it's called B modes because it has the same pattern as B fields, many fields, right? And so they got a pattern from that and it's only when combined with the, and yet up to that point unpublished Planck data,
36:41
you saw that you could explain their data by simply the magnetic, dust lined up in the magnetic fields of our own galaxy. And I've been expecting for the last two years there'll be new results out. It hasn't been coming out. That tells me the limit's getting lower when I talk to the people.
37:01
And so they rushed to report with overconfidence and that was unfortunate and because science is about making the discoveries and then having it backed up and so forth. And the reason that light bird can do it is because we know much more
37:20
about what the backgrounds and the situation is and light bird is going to be from space and therefore it can cover the whole sky and if you paid attention, it was at what we call the low L modes, the low angular frequency modes, which is the very largest angular scales and they also have to make a very careful measurement
37:41
of the E modes in order to do some de-lensing. So there's this little bump that sticks up and then there's a little place where it's sitting underneath the background. That's how they're going to be able to do it and so far the ground-based experiments may be in being more sensitive but they are over a more limited part of the sky and they have to be fortunate
38:01
to get out through that window. So who wants to put the last question? You invite. Yes.
38:27
And my second question is, besides the measurement of the beam of fluctuation, what would be the most promising measurement to help us better understand the early universe? All right, so my first response is,
38:42
please ask Adam Ries. Because he's the person who's pushing this the most. There's some of us who think that there's a discrepancy and it was originally two sigma and then three sigma and now it's almost four sigma and so now you're starting to have to pick it more seriously but we kind of think everything's fitting together so well.
39:03
It's surprising to think the nearby universe is different from the more far away universe but it may well be. This is how the storm clouds gather on the horizon and a whole new thing comes out. It would be surprising but we'll see. And Adam is the proponent who will tell you a lot about what's going on.
39:22
I am crossing my fingers that things resolve easily but the fact is there's a tension. You can fix it by putting in an extra neutrino or doing this or that. You know, our neutrino colleagues didn't like a new neutrino show. There's a number of things you can do but it remains to be seen. All right, now I forgot the second question.
39:42
The second is besides measuring the B mode fluctuations, what would be the other promising directions to help us better understand our universe? All right, do you wanna answer this one or I don't wanna do this? I think we sort of run out of stuff to measure. Well, there's dark matter. So one of the things I think is
40:00
we start seriously thinking about how can we find another handle on what the dark matter is in order to see that. So come to this afternoon, the dark matter panel and we'll have some discussion about that. We want to get our limits on dark matter much better but there are actually six possible candidates for dark matter. So we can make observations and we can make observations astrophysical
40:22
and cosmological observations but we can also make things like our McDonald was talking about or my friends that worked on Lux and so forth. There are ways to push the various limits down and that's one of the areas where we can, it's only been a problem for 70 years, the dark matter. But it's about time to make a little progress.
40:42
Okay, I think that's a good way to stop and remember the panel discussion. I know that many of you still have questions. There will be some opportunity for you to put this question to the panel. So let's thank the speakers now for this.