his thoughts on a path the path for peace. we wrap up our lineup. on the relationship between the united states into and saudi arabia. that all happens tonight on book tv.

c-span in the house. [laughter] [applause] tonight's book is call welcome to the universe and i love saying that. welcome to the universe.they tee that too. let me immediately introduce my coauthors, first michael strauss. [applause] these are my two coauthors. [applause] so have a seat. so just a bit of introduction.

i taught for ten years at princeton university from 1994 to 2003 and before i transferred all of my activities here to this museum but over that time i taught a course on instructory astro physics. we realized we could charge, we could energize the course even more by adding other talent that has expertise that could see the curriculum, see the syllabus, in particular michael strauss is an expert on our galaxy, its structure, large-scale structures of the universe in particularly. in fact, ph.d thesis was mapping the universe. >> that's right. >> in fact, we met in the andies mountains of chile and we became

good friends and colleagues. jay richard gott, the third. while michael and i take you from stars, planets, galaxies to the big bang, then we hand over to rich got,. you say where do you go after that? and there we learn all of the beautiful and bizarre nuances that make our universe what it is pivoting on the brilliance of people like albert einstein and theories of relativity. rich, why don't you begin -- i

have to tell a quick anecdote. we are coequal coauthors and our names are associated with the lectures we have given and we speak to publishers who is princeton press. tyson, you're better known than the other two and you have to name the big name and i said, no, we need your name big because you know the publishing industry your name starts out small and as you get more known then your name is like the same size as the title then eventually is just your name, the title on the cover. so selling your name rather than title of the book. your colleagues and they handed it to the when are theists, the artists figure out how to do it. so my name, yes, it's the biggest thing on the cover, what they did is put it on a planet that's closer to you. you see that. >> weare just on planet receding

to the background. >> if you have to do it be artistically clever about it. >> rich, why don't you give us a perspective of rich has show and tell here and we will just sit back and watch because rich got, i never know what he pulls out after his bag even today. so rich, what do you have? >> okay, well let me start off, when my granddaughter alisson was born the first thing i said, welcome to the universe, often a phrase you hear from niel. when you are born you become citizen of the universe. this book will help you with that. we start off telling you how big the universe is. i brought models to i list trait that. this is a hydrogen atom. it's a billion times bigger than it's supposed to be.

if you have a billion dollars, you're a billionaire, billion is a mig number. a billion times bigger than a hydrogen atom. this is the electron in orbit around the proton, this is the atom. this is a proton and the actual size of the proton on this scale would be one ten thousands of an inch so most of the hydrogen is empty space. most common atom in the universe and most common atom in your body. there's nothing really intermediate in size between an atom and the nucleus of an an atom.

one thing is called muronic hydrogen. instead of electron orbiting around it it has a heavy cousin of the lek -- electron. the orbit of it is 207 times smaller so in this scale a 20th of an inch. it reminds me of -- discuss anybody see honey, i slung -- shrunk the kids? they have adventures in the backyard. it's not quite as crazy. all your electron were replaced by muons you would shrink and you would be tiley.

unfortunately the muons decay back into electrons and they do this an the time scale of 2 millions of a second, a very short film as you go for the short film oscar, you know. another thing that's immediate in this size, take uranium, 146 neutrons in nucleus and if you strip all electrons it would be 92 times smaller than this, so a tenth of an inch. there are some things and we have made these actually in the lab. both of those things, so between atom and the nucleus of the atom.

so this is small. let's go the other way. >> i'm going to hold. >> thank-- niel can hold it. >> you suspended something in the middle of it. >> that's symbolic of the proton. you can see it. let me go the other way. i'm going to go up by a factor of a billion. suppose we shrink the earth byia factor of billion, here it is. marble, half an inch across. i've got conned innocents painted on here. this is an actual globe of the earth shrn -- shrunk by a fact of a billion. let me get -- i have the moon in here. the moon is so small. [laughter]

>> here is the moon. >> we can all see that, rich, really good. >> eighth of an inch. the moon would be 15-inches away. this is how far humans have gone in the apollo program. this is the further we have gone in the universe, 15-inches in a scale of 1 and a billion. that's how far the moon is away from the earth and -- okay. >> how big is the sun? well. here is the sun. this is how big the sun. >> is that a hot wheels track? >> yeah. >> i've got to spin this so it makes a sphere. [laughter] >> this is how big the sun is.

it's 55-inch and 500 feet away. that's how big the sun is. >> if earth is that marble, you heard of earth of a blue marble. there it is. wasn't and a billion. [laughter] >> this is the sun, how big the sun is and it's 500 feet away. that's it for the sun and now the question would be well, how far away is the next nearest star. the sun is a star, but there's proxima. here it is. so here is proxima a sentora, 4.3 lighting years away roughly. it is -- that means it takes life about four years to get to to us from it.

>> just to be clear, that's the actual size of proxima, relative to the sun dropped back on the stage. >> relative to the earth here too. this is a scale of 1 and a billion. smaller than the sun and this would be on the model, this would be 24,000 miles away so we could go all the way around. he's holding proxima sintora here. 25,000 miles away from us in the model scale and we recently discovered a planet. there's a planet going around the star. it's a little bit bigger than the earth and it's about 24 feet

away from its star here. this is a planet little bit bigger than the earth and it's close enough to the star there that it only goes -- should always keep one space toward the star and the other is it orbits around so one side is going to be too hot an the other too cold. so not to be habitable. that's how far away it is. >> okay, so rich, we are keeping the same scale, you the moon, the blue marble. earth blue marble. the moon 15-inches away from the blue marble and then the sun that size and then proxima 24,000 miles away. >> a lot of empty space. >> the farthest that we have been is the moon.

what hope do you have for the future of space travel? >> well, you have to get that much better. [laughter] >> stupid me. >> you have to spend more money. [laughter] >> okay. >> so, okay. let's go by another factor of a billion and i will show you a model in a scale of not one over a billion which is what we just saw but one over a billion billion. this is a billion times smaller also. so here is the sun, here is the sun, here is the sun and there is alpha, alpha sentira, another solar-type star. it's part of a triple star system that includes proximate sintora.

a triple-star system. 4.3 light years away and here on the same scale is serious, a blue star, you've seen that in northern skies the brightest star in the sky. it's about 9 light years away. these are near stars from us and we are living in the milky way. it has 300 billion stars in it and it would be about 8 tenths of a mile across on this scale, a big disk of stars and they are about distance apart and if you went to the model in a scale over a billion, it would be like going through a snowstorm of stars and the next nearest big galaxy to us is andromina, another galaxy about 20 miles away on this scale. >> so rich, if you got another

299 billion, 299 million -- >> i need to work on this model a bit more. [laughter] >> yes. >> so now we have that scale, let's two up another factor of a billion, now let's look at a model in the scale of one over a billion, billion, billion, it's a billion times smaller than this and then you can see the entire visible universe here. we are at the center of this. this is the cosmic microwave radiation. the radiation from this cosmic microwave background which is left from the big bang has been coming out for 13.8 billion

years, the radius is 13.8 billion laight years and so we look in and out space, we are looking back in time because of the speed of light and so this is as far as we can see. and inside this there are 130 billion other al -- galaxies and so this is the cosmic background that we can see. we can't see anything beyond that from those regions they haven't had time to get to it. >> you put yourself in a rather privilege vantage point to show that? >> yes, this is what we see. if you stand on top of the empire state building, you're going to see a circle out to the horizon and if you go to the

tower in chicago, you're going to see part of chicago, centered on you. so the part you can see is always centered on you, that doesn't mean you're special. [laughter] >> everybody sees that. so everywhere you go, there you are. [laughter] >> so this is -- we see this and we have reason to believe, though, that the universe is much bigger than this because the fluctuations in this are only one part in a hundred thousand. we believe the universe is at least a hundred thousand times as large as this and probably much larger. the best theory for explaining in detail the pattern of fluctuations that we see in the cosmic mikewave sphere which is based on observations from the satellite is the theory of inflation, which alan put forward in 1981 and in that

theory that explains how the big bang got started. you could have started 27 centimeters across of vacuuming state. what is that? well, we are used to thinking of the vacuum as being empty. if everybody left the auditorium here and if we took away all the air and we took away all the photons, completely space i would think there's zero energy density because of various fields going through the universe, the the universe can have a vacuum energy and nonzero vacuum energy. fit has a nonzero vacuum energy because we would like the vacuum not to have any privilege standard, if rocket ships are

going at same speed are going to measure the same vacuum energy. it must be that this vacuum energy is associated with a negative vacuum pressure that operates in three directions, front, back, left, right, and up and down. and this is uniform pressure so it exerts no hydroeffects. you don't know because it's uniform. you have to have difference in pressure to make the wind blow and knock you over. this is uniform pressure. no hydrogen affects but it has a gravitational affect according to relativity because pressure gravitates as well as energy in space time and so that means that it has a repulsive affect

and it operates in three directions and three times more potent so this causes a gravitational repulsion and it starts the universe expanding and expands faster and faster in accelerated rate. it keeps doubling in size, ten to the minus 38 seconds. so in the first ten to the minus 35 seconds of the universe's existence, it could double in size a thousand times and ten to 300 in size so it can become truly enormous. this explains why the universe is so enormous and why so uniform as it is and in detail, it can explain the pattern of fluctuation that is we see. we -- so the theory of inflation is effective of explaining this. one of the problems it had, though, that what you want to have happen, you want this high energy vacuum in the early

universe to decay into normal particles to make the hot big bang that we see, we wanted to dump its energy into the form of normal elementary particles and so the problem with this was that it's like you're trying to boil water on the stove and have the water represents this inflating sea of vacuum energy which is inflating very, very fast and you want to to turn all into steam, ordinary particles, but what happened is if you ever blow water on the stove, what happens is it forms bubbles and so we expected to get bubbles of particles forming on this and that didn't look uniform. i was one of the people, myself and andre, proproposed in 1982 that what happened was that we were living in one of the bubbles.

from inside the bubble it looks perfectly uniformed to you. so this solves that problem of nonuniformity and that theory predicts in a very general way that once you get inflation started it's really impossible to stop and it's just going the keep making more bubble universes forever as it continues to double in size and eventually get an infinite number of bubbled union verses and can have different laws of physics in them so you get a diverse. we actually think we live in a multi-verse, this is all fast compared to the tieby region we can see. one of the reasons we believe that the other universes out there exist is that the theory of inflation predicts it and the theory of inflation as we show

in the book beautifully explains the pattern of fluctuation that is we actually absorb in the cosmic mikewave background. universe is going to be doubling in size once every 12.2 billion years and today it has allow vacuum energy of seven times ten to the minus 30 grams per cubic centimeter. this is another reason we believe in inflation. i talked about sizes in the universe and one of the people

think that pluto got demoted was because of size, i would like niel to tell us about that story because he was a big participant. [applause] >> you took us from hydrogen atom and then you dumped pluto in my lap. >> elegant transition. >> i think in the visual above my head we have what are called the planets, mercury, venus and mars, the moon is shown there which looks quite small. something to know about our moon is it's one of the largest moons in the solar system. even most of the moons of

jupiter and saturn are dwarfed by the size of our moon. we have an uncommonly large moon relative to us in spite of how small that looks. we have history here with pluto in this institution and back in 2000 when we opened the center for space, we were first out of the box to reassociate pluto's identity from the company of planets to the icy, dirty ice balls in the outer solar system. specially little kids saying, they are angry, pissed off third graders saying, how could you -- just because it's small, how could you do that. thinking that size was an issue, in fact, it had much less to do with size than you might imagine.

if we go to the next slide here. what do we have. now we have the gas giants, jupiter, saturn, neptune and then you get to see how small earth is relative to the rest of the action there. because earth is included in this for scale. so here is a point i will make and i don't get to make this enough, jupiter is more bigger compared to earth than earth is compared to pluto. i don't know how else to con conjugate those verbs in the sentence. in other words, if we are on earth saying we are big enough to be a planet then pluto isn't, imagine what they could be saying, the solar system only has four planets, jupiter, saturn neptune and everything

else is a debris. [laughter] >> i'm certain all life forms of jupiter are thinking exactly that way. so -- so you can't invoke size exclusively to this pluto in this regard. allow me to tell you that our moon, as small as it was compared to earth has five times the mass of pluto. some people over here, pluto lovers were never told that, were you? yeah. [laughter] >> welcome to the company of informed people, right, regarding pluto, so -- but we knew this. so pluto had other issues and -- so after some thinking about this, pluto got demoted to a dwarf planet status on several

tbrowndz, one of which that it orbit it is sun in the region of the solar system where there's plenty of other stuff orbiting there which in total dwarfs pluto itself. pluto does not, how do we call it, own orbital place in the solar system. it's shared with countless thousands of other icy body that is rival pluto in size and composition, so what we really discovered was that pluto really never was the planet we wanted it to be. in fact, it took 60 years the icy we named for astronomer at mid century who hypothetical sized that there could be excess debris that didn't participate in the formation of the rest of the planets. so pluto is a very healthy

object but a really lame planet. so just to make that clear. now, when we look for other planets which has been quite the pass-time in last several years, i'm curious if there's anyone in the audience who is 241 and younger, raise your hand. if you're 21 and younger. several of you. you were born in 1995 or later. well, 1995 was the year that we discovered our community of physicists discovered the first xo planet. first planet orbit another star. so i want i want to generate xo planet. you have only known life in a world where we have known a world beyond the backyard of the solar system and so what a privilege that is. so in our book, we calculate how

you might go about finding xo planets that would be of particular interest to us and what is it that you be after rings, although they are quite beautiful, you are really after if they can harbor life. life as we know it, perhaps life of any kind. so there are ways to approach that problem. one of them is called the drake equation. sure. put them up. an image of drake in the corner. i think he's much older than that now. is he still alive? >> yeah. >> good to know. he's 130 last i found. so frank drake who was early in this exercise of asking what is the likelihood of us communicating with alien

intelligence that could lurk in a planet out there in a galaxy, and so he came up with a clever way to attack the problem. so you come up with an equation that -- that's him writing his -- the drake equation sitting under his pin in that photo, what i've done in this slide is made a simplified version of it to get the idea across but there are several other terms in the equation that he's written. we will start with a simplified version. what we want to calculate is number of civilization that is could be out there. let's just start with that. this would be life achieved intelligence and created organized societies, civilizations, so that's the curly end, the number of civilizations, how would you go about doing that. well, what you want to do is split the problem into multiple bits and each bit, each part of that problem could be entire science projects to try to address and that way what we say

in our fields you unpack the problem separating the variables otherwise it's this mail stream and you don't know if you're coming or going or what's influencing what. so we start out with how many total stars there are that you could be searching and that's n stars. in this case the number of stars in the galaxy. the milky way galaxy. that's coming lately at about 300 billion. over the years you might have seen a hundred billion, carl said 400 billion, this is just -- those numbers are all the same to us. what's a few hundred billion between friends, really. i say that not facetiously. there are galaxy that have a trillion stars and galaxies that have a few hundred million. if you factor a hundred billion that's the same number to us given the range of sizes of things that are out there. so start with the number of stars and what you want to do is ask, what fraction of those

stars have planets because you're going to look for life where there's a planet presumably. you don't expect life thriving in stars. that's hazardous to molecules, okay, and life, what fraction of those have planets, so that would be the astro physical exercise. you create a telescope, mount it on a satellite which we have done and measure it is piece of the sky and measures for what fraction of the stars and which has planets, you can do that. it turns out not all planets are good to life. some might be too hold to the far, too hard or too cold for what. life as we know we know it requires liquid water. so you would want the zone

around the star to be just right, the goldie lox zone. if you're looking for planets you want planets in that life zone. fraction of planets in goldy lox zone you can imagine has its own term separately measured from stars around them. now we have fraction that has planet that is we can sustain life in goldilocks. is it half of those, is it a tenth. we don't really know. so not all these terms have equal -- equal confidence in the numbers we insert, okay. but you keep going.

if it does have life what fraction of the star that is have planets in the goldilocks zone that have life, what fraction of those have intelligent life? so here we are hacking away at the number 3000. whatever the fractions are, you're hacking away at the number but it's a big number so a lot of wiggle room to give you something left over at the end. so you keep going. by the way, these are civilizations you would talk to in some way. well, how would you do that if they don't have technology to send signals through space? think about it. most of human cultural history, we had what we would call intelligence but there's no way they could have had a conversation with an alien. they didn't have technology, they didn't have radio waves, they didn't know anything about

it. just because you're intelligent doesn't mean you are -- that you're a candidate to communicate with. as this is set up, we are just could wanting civilizations but you add all up all of the terms and ask how long have we been able to use radiowaves, maybe a hundred years out of thousands of years of culture human history, a hundred years. you through a dart at the timeline of civilization, what fraction do that blindly does the dart hit us with our capability to communicate with aliens? it's a tinny fraction. so if you come upon a planet randomly and there's life, what are you likely to find? that's the kind of questions that are addressed in this equation. when you put in the very latest numbers, you put in all the numbers and all the terms, what we come up with is, rich, what's

the number of civilizations in the galaxy, what was it? >> 1.8 billion habitable planets. >> planets in the the habitable zone. >> earth-like size. >> 1.8 billion. billion. [laughter] >> just go to director school -- >> and maybe. and maybe as many as -- >> rich, so that would be like -- those are planets capable of hosting life as we know it. >> first couple of terms. and the we're one could be as big as or maybe smaller than but could be as big as a hundred that are communicating with radiowaves now. >> a hundred in the galaxy. so that's hopeful? >> hopeful and there are other galaxies. don't forget about that. >> if we go to the next slide, rich, here is an image taken from the southern hemisphere of

the milky way galaxy. so let me explain to new yorkers, this is what the sky looks like. [laughter] >> if you remove the buildings and the light and the pollution, one day i want to write a novel that implicates the amateur astronomy community for all the major blackouts that new york has experienced. you park the curtains and they they were like venus and the moon and so it's stunning and just to embrace the sheer scale to search for life in universe, but there's 1,480,000,000,000 planets inhabitable -- >> 1.8 billion.

>> 1.8 billion scattered across the galaxy. the plane of the milky way galaxy. we are within it. all the other stars that you see above and below are also part of our galaxy. they are just really close to us. they are a blueberry embedded in a pancake. you can look out above and below and escape the doug of the pancake but if you look within the pancake, it's just pancake all the way around. when you look in the plane of the galaxy, we have galaxy all away around us. this completely wraps the sky and i want to note for you, rich scott mentioned that our nearest large galaxy is the andrometer, name so because it appeared among the stars but, of course, it's much farther away. they are part of our own galaxy. a screen door out to the rest of

the universe. this image in the southern hemisphere has two fuzzy cloudy things off to the bottom there and -- what's that? >> just pointing the map. >> my people know where i'm pointing. [laughter] >> was i not clear? two fuzzy things. they look like clouds and while native inhas been tenants of the southern hemisphere surely knew about this, we in the west first learned of it from the journals of magellan went through the southern hem steer saw the clouds, noticed they never left. but he still called them clouds because that's what they looked like. we know now to be dwarfed galaxies in orbit, gravitational

bound to the mill ri way and so they are nearby, and by the way, it's not all roses for small galaxies and orbit around big galaxies. we have a record of small galaxies that once orbited us that have been completely cannibalized and we see just the stream of stars fully absorbed into our own solar system. i mention because we will make mention again. i believe that's my last -- just to be clear, i don't know if we can dim the lights. we will see if c-span can handle it. there we go.

what you have here is one of the most famous images ever taken by the hubble space telescope, the ultra deep field and by deep we mean how far into the universe does that picture reach. and, of course, it's a nasa photo and notice there's a reddish object with spikes. that's a star sitting on our nose in our own galaxy. that might be the only star in the photo. yes, it is. every other smudge, specof light is beyond the stars of our milky way and they represent entire other galaxies. each containing hundreds of billions of stars. so when we talk about the probability of life, we generally contain it within our milky way, but if you want to multiply up, you've got -- you

would have -- you would be inexcusebly centric. this area on the sky is a tinny fraction of the area of the full moon. that's how you recover these numbers such as the universe contains. >> 130 billion. >> latest estimate 130 billion gal axies. we can bring the lights back up there. let me hand off to mike, what can you tell us, mike? >> i have to move. >> you have to move, sorry.

[laughter] >> niel, i think you were using the telescope there. >> briefly but on the .9 meeter. >> ly use the 1.5-meter. you can see the milky way rising dramatically. one of the frustrations even if you get away from new york new york city's bright lights, they are not visible to us. you to travel to the southern hemisphere. >> can i just add something to that? >> memory lane. this is at the summit at the andes and occasionally you get weather that's below you. cloud -- total cloud below you. if there's any moonlight at all

and you look out over the edge of the mountain, it is like you are -- you are are somewhere on unreal. you are other worldly because you're an island in the middle of clouds and there is no earth. it's just you, the cal scope and the cosmos. >> with that -- [laughter] >> we may be the last generation of astro physicist who went to mountain top to get our data, plane to santiago and transport to la sorrena and mule train up the mountain and live nocturne

nocturneally because the day becomes your night. within a few years of that we have surface observing, we send your coordinates and they point the telescope. they send you back the data and you never left your desk in your office, so it's way more efficient but i think it's absent some of the romance. >> which i was about to talk about. >> sorry, i will shut up. go. >> what we do is set up a long exposure and the telescopes were automated an took care of themselves. we enjoyed the spectacular view. it is wonderful and so there are several telescopes as you can see and we often bump into each other in the mountain top enjoying the view. in addition to niel and myself working on our respective ph.d thesis i met the woman who later would become my wife.

she was on the .49-meter about 30 years ago. i just we wanted to mention that here. [laughter] >> le talk a little bit about what the nature of the milky way is. we have seen that it's 300 billion stars. one of the questions we want to ask yourselves, really what is a star. they are tremendously hot, rich tell how enormous they are. a star is a ball of gas held together by its own gravity but held up together by internal pressure and giving off as we see a great deal of heat and light which is in the case of the sun what keeps -- what keeps us alive. one of the great discoveries indeed, stars are made upmostly hydrogen and helium.

hydrogen and hell -- helium tom nate and the make-up of our bodies, neon are a small fraction of the atoms of the universe. how is it that the universe has come this way? came from the big bang itself. the the early universe was tremendously hot, much hotter than the surface of stars. temperatures that ranged up to billions of degrees. we would like the billions, of course, far better than i can. >> billions. >> i will practice, niel.

>> point me -- to me. >> molecules could not exist, it was so hot that the only thing that could exist were the present discussion of protons and neutrons, the core, nueceil of hydrogen and atom. some of the protons and neutrons came together. hell yuimnuclei that was produced. now measured by measuring the specter of stars. that's it. it turns out not to work.

so we need another explanation to see how those heavy elements are made and the answer is going back to the stars. if you go back to the sun and ask, oops. there we are. if we go back to the sun and ask the question, what is happening in the center, what is the fuel source that's causing the sun to shine, the answer is in the very core the sun where it's 15 million, not billion, million degrees and tremendously high pressure, they can fuse together a process called nuclear fusion to make helium nuceli. hydrogen is being formed into helium and that is a process going on in the sun right now. the story gets much more interesting for more stars, our

own sun will be able to burn hydrogen into hell yum and later turn hell yum into carbon and oxygen which are primary elements that make up our own bodies. but if you want to get the periodic table you need star eight times massive as the sun as it continues to grow and use up first the hydrogen and then the helium and start creating larger massing, working your way up the periodic table. now, it turns out that iron which is element number 26 in the periodic is the end of the story. you cannot combine iron with anything and get energy out. it requires energy to combine energy with anything to make a heavier element and so what -- so when the star gets to the

point where the core is made truly of iron, then the interior energy source is gone. the source, the stars being held together by gravity, i told you that the furnace in the center is giving you a pressure that's holding the star up. you turn the furnace up, the star has no choice by to collapse and collapses catastrophicically and explodes, the outer parts of the stars that have not yet reacted undergo nuclear reaction and the star explodes. let's go ahead. what we are seeing is the -- aisle, this is your favorite word, smithereens. known to be a star that exploded in 1054 ad, the chinese left

records and saw it explode. a guest star that appeared in the star. it was bright enough to be seen for several weeks even during the day. we look at the position in the sky and we find this dramatic residue of that exploded star and the gas that we see here has all the heavier elements built into it. >> this is the guts of the star not the star itself? the blown apart guts? >> that is right. >> really nasty looking. but also astro physicist today celebrate that explosion every year because the chinese observed it on july 4th, so we have fireworks in the astro physics community celebrating, just fyi. >> it turns out that in that explosion it didn't destroy the star completely. right in the middle of here, i don't know, maybe that spot right there, i believe it is.

something called the neutron star. incredibly dense center part of the star maybe about the mass of the sun made up of essentially pure neutrons. tremendously dense. one symbol full of neutron star, i think, we said weighs about a much as 100 million elephants, if you can get your mind around such incredible thing. so remember i said that the iron that the star can make only iron and then the process stops and then the star explodes as super nova, there's so much energy this n that explosion that heavier elements can be made and so there are two different stories that we now are trying to understand as possible ways to make the heavier elements beyond iron in the periodic table. one is that they are formed in the explosion of super nova and

the other you imagine that you have two neutrons stars and they clyde together. that's another way to give you that energy to get those incredibly heavy elements. think about it. the gold in my wedding ring here is formed in the center of an explosion just like the one we see. in fact, most of the atoms in our body, carbon and oxygen and all the other elements other than hydroagain and helium were formed in the stars one way or another. that was the super nova in 1054ad. a super nova went off. this particular star got an arrow, exploded, boom. for weeks afterwards astronomers

meeting each other in the hall and say boom and be incredibly excited. [laughter] >> it was a fun time to be an astronomer. i was lucky in may of that year, i think this may be the time that i met niel, to travel to the southern hemisphere. the cloud is not visible to us in the northern hemisphere. you have to travel to the south. 150,000 light years away. that light of a single star was visible. >> michael, the guy who discovered this was in the telescope dome when it happened and he just didn't believe it and so he just went outside and looked up. there it was. [laughter] >> there's a new star, very dramatic. it was closest super nova exploded to us in 400 years since the invention of telescope.

>> plus the literal translation of super nova means super knew. >> super new. it's a dying star. a new star to you if you don't know astro physics, that's what that happens. yeah. >> i want to go back to the milky way and talk a little bit about that. niel did not mention that his own specialty in his thesis was studying the stars in the have center of the milky way. this is a movie from the european southern observatory zooming in to the milky. we are going to the very center, a special place because niel studied the stars there but at the very center we find something that's truly dramatic, there's a black hole sitting in the very center of the milky way. a black hole is black, it is as you probably know something so dense that nothing can escape from it, not even light, so how can we infer existence if it is

almost by definition invisible. well, it has no light for us to see but we do see, we do see gravitational influence on the stars around us, so this is a diagram indicating observations by andrea and her colleagues at ucla, what she has done is mapped the orbits of individual stars in the very center of the milky way where we have zoomed in to the very center. what you see the stars all seem to be orbiting around a single point right in the middle there. marked with the star to guide the eye. no light is seen at that spot but you can infer from the orbits just how much mass must be associated and also get some limit on how large the object is. so we see something that's invisible, very, very tinny and incredibly massive. 4million times the mass of our own son and what, indeed, that

an object we infer as black hole. incredibly massive and dense. indeed, one of the great discoveries of the last 145 or 20 years is the realization not only does the milky way have super massive black hole in the center but, in fact, all galaxies seem to have a similar super mass i have black hole with masses up to a billion. niel, please. >> billion. >> thank you. a few billion times the mass of the sun. one of the things that that's been part of my scientific studying the massive black holes. i said that a black hole is so dense that we can't see it. no light can possibly escape. there's a way to -- another way to infer the presence of a black hole. imagine that there's gas flowing into the black hole as it heats up tremendously and guys so

brightly, so brightly that the glowing brightness can be seen most of the way to the edge of the observable universe. we know the universe is 13.8 billion light years away and therefore that represents a limit, the visible universe, part of the universe that has had time for the light to reach us. and so what we see here, you see the arrow points -- good thing we have the arrow there. points to -- the light travel time distance seen at a time when the universe was a mere 4,900,000,000 years. studying such objects gives us important clues to understand how the universe evolved and what was going on. >> so michael, when he discovered pluto, gave a series of lectures about it and there's a little dot on the screen.

>> how did you know it was pluto? >> there's an arrow. >> very much much a needle in a haystack. [laughter] ..

the lost energy caused it to get together and eventually to merge. it has been predicted for a very long time. the laser observatory i think i said that right. it was built to measure the subtle distortions after the wave passes by. it consists of an extremely long ruler. unmeasured a change in that length by about a thousand. a pair of black holes 129 times the mass merging together to make a single black hole with a mass of 62 times.

it does not equal 62. something seems to be missing. that missing piece is the energy loss in the form of gravitational waves. e equals mc squared. in the collision of those two black holes. and we detected the faint trace of that. they are proving directly in some quantitative detail that that actually exist. that conversion of those multiple solar masses made this the most energetic thing in the university -- in the universe by a fraction of a thousand. we are now at an important

threshold in our study. it was truly an exciting development. this is just a quick diagram showing the actual measurements and some comparison with what was observed. it will talk about the future here. one of the wonderful things about this we heard this in some detail from rich. there is a lot of exploration to do. we are very much in the expiration mode in the sense that by making maps we can learn about that. by just seeing what's out there we can see what's happening. has been built just literally

one mountain over. and an artist consumption of what it does is being built now. it will start a ten year's survey making a map of the sky not just one map but multiple maps repeatedly asking the question how does the universe change. can we see new exploding stars can reseat new asteroids. or phenomena that we have not have the imagination yet and i mentioned that 30 years ago sophie had sophia and i met each other we were very lucky to be able to travel to chile last year for what was about the 21st anniversary. and it was also the ceremony marking the start of the construction of the

observatory. here is a two of us standing on the mountaintop. the mount topic where mount tab where we met. again starting the construction are we allowed to stand that close to the emergency tone. see mac what that i think we are to change modes here and turn it back to rich. in the book we have a map of the universe that stretches over several pages and from left to right this is a panorama looking out from the earth's equator and then vertically it shows distance away from the earth. it's about the preserved shapes and this is like the map does on the earth. each constant step outwards as is further away from the earth.

let me point out here. there is the earth's surface on there is a satellite going around. it's made very clear here that the service in a way as the shoreline of a cosmic ocean that lay before us. it is a idea has been that has been with us for some time. there is the moon. this is a satellite that measures of the background and this is a solar observatory that made the measurements of the sun that we saw. i know were getting into the realm of the planets from which we heard about. it's one of the things that could render us distinct. one of the things that it will do is try to map those and

find out if any of those are going to hit us in the head. this is the furthest we have of a voyager one and two. it's a transition between the sun and its influence on its environment and the rest of the galaxy. so what is julius caesar's comment. we have another zone of comments predicted by a dutch shaman or not as countless topics. it's very far. it is the name of the entire system. one of which is proxima's.

this is a radio bubble. it's how far they have reset with space. the 1936 olympics some of the first signals that they will receive. never see now were seeing the entire milky way here. the black hole would be right there in the center. that is a distance you would find them. we had factors of ten each tick mark that we go there. now we are into the realm of the galaxies. a number of other galaxies that had names like whirlpool. we call them as we see them.

you know i'm right. don't even go there. there is the wall of galaxies. it's in the guinness book of world records for the largest structure. it represents a single galaxy. and finally we had reached to the most distant galaxies in place it will be right here and rich do you want to tell us about that. they stretch it all the way 360 degrees around the sky. it shows you with that sphere that we see all around us that is light coming to us left over from the big bang.

ladies and gentlemen. thank you. [applause]. that's about 5% of the book. we would love to take some questions. we will be out in the hall of the northwest coast to sign this. this will be a unique thing. just so you know. it's a about ten minutes of q&a. if you must leave now because you parked too far away you can pick up a book that is pre- signed.

we encourage children in particular to come and ask questions. the microphone does not work. we will come back to that. >> we might in the future. thank you. does this work yet? can you explain why there's no a center of the universe even if you are looking at it from where the edge of the uniform is. if you imagine a big balloon with coins on it. and it is blowing up. this is a picture of space expanding if you sit on the

coin you will see all of the other coins fleeing from you. we think we are standing at on top of the earth. and the poor people are hanging upside down. everyone thinks there at the center. but there is no particular center. just the space that is expanding. you see the region around you. wherever people were they thought they were there. first of all great lecture. in your equation for the number of possible planets there is another part that has made it unique.

we have this is the satellite. it have much to do with making the earth habitable. it doesn't have a large satellite. the atmosphere was never stripped away. i'm wondering one -- what affect would have to be looking for within in order to define it. in the formation of not life itself. it's whether you can have the stability necessary to develop the complexities that they have given us that we see. my opinion there is that it's a little bit overstated how important the moon is.

yes it stabilizes just think about how diverse life already is. it's thriving. so what if something wiggles it up a little bit more. i could've added even more biodiversity from the system. it will render some animals extinct. i'm not worried that now we have to look for habitable planets i have a big moon. i agree with that. one tends to get very specific about the earth situation and say it must be followed exactly that. there is a variety of ways to do that. moon is a bit more detail.

>> the sun gives you that also. you strand them. it doesn't seem absolutely necessary to make why is our moon so big. our moon has a fascinating back story which he did it take shape until after the apollo era. a certain amount of carbon and oxygen. but also some iron.

in the own planet it has hardly any iron. why is it in the core. so iron goes to the core other things rise to the top. and then it is solidified. the moon if it has no iron anywhere and doesn't have an iron core what happened. that let us to think that maybe the moon was formed later. have led to the hypothesis that an object side swiped earth scooping up our service material reforming into them what became the moon. it's not far-fetched because in the early part there is. it's a very heavy bombardment where they are still accreting leftover material from the formation of the solar system. if it's small you just absorb it. the moon just to be clear is a

little heavier than 1100 the mass of the earth. it's also not that much material to give of yourself to make the moon. your neck in a mess i promise. so that is a whole separate storyline. that is how we can get a big one and they don't. a big fan. if i could be ask a personal question.

on both science and pop culture. how does someone like you managed to do things like that. it is a cloning. and as a great question and it's nearly impossible. and i miss a lot. but what i do is i look to see what is the number one tv show what is the hottest team right now. so the cubs are in the world series limit check up on that. i allocate my energy so that the things that garner the deepest and most intense public attention than against me fluency in the places that people care about and then i take the laws of physics it's but they can already fit in. and then you walk away not

having to learn the science is a separate exercise because it plugs into something that you already know and love. an example of this was i was channel surfing and there were two examples of this. i'm channel surfing i 15 minutes until the movie i want to watch and i get a football game that just ends in a tie. so they go into 15 minute overtime. i said i can fit that in. let me just watch this. why not. we to change hands a couple of times before. and then it's sudden death. then the guy gets close enough for the kicker to kick the field goal. and then it sort of drifting to the left. and it hits the left upright and then bounces and for the win.

and i said wait a minute this is a round ball. i checked the orientation of the stadium was against it. was enabled by a third of an inch drift in the trajectory of the ball empowered by the rotation of the earth. i did not had to explain what the field goal is. that was your scout. and people lost their minds on this.

phone calls from all over. it was a very simple exercise. anyone of my colleagues. i don't carry special knowledge i just happen to do it they're actually busy in the lab. that's how it happens. with the proposed ideas you're talking about the recent announcement where you have these nano crafts that are propelled by the pressure of laser light where you can accelerate to such high speeds. >> they have a billionaire working on this. several people in our department was working on this. that group celebrated when

they found this planet around that. it gives them a goal to go to. the easiest start to go to. they are working on this. given that we have a super massive black hole is it actually collapsing in on itself. >> imagine the sun turns into a black hole tomorrow. this would be bad news for many reasons of course. our source of heat and light would disappear. but the orbit of the earth around the sun would continue exactly as it is. it has a mental image of the black hole as a cosmic vacuum

cleaner. if you are in orbit around the blackhole it's just as stable as an orbit around the star. should a movie in which we sought the orbits of stars around that central black hole and they will keep on going for literally billions of years. it's only when you get very close to the blackhole that could swallow things. they will stay on for any timescale. it can eventually take over. our milky way is quite safe on timescales to that. 4million times the mass of the sun. i would say 10 million or so.

we have blackhole envy. so one of the hubble telescope's. every galaxy that we can measure has a super massive black hole in its core. it's another ingredient in the modeling of people who want to know how to make galaxies in the first place. this thing about this. there's an old joke that says there's no such thing as granted 30 the earth it just sucks. that is so cool. and it's a school night. just say you are here to the

background it's basically a bunch of microwaves that comes inside. you could make a cosmic microwave oven. >> we are in a cosmic microwave oven it's a very low temperature. about 2.7 degrees above absolute zero. we are getting in these microwaves these microwaves all the time they are left over from the big bang. they used to be very much shorter wavelength but the university has expanded. it's very cool. as i going to burn you up. thank you for the encouraging information. try this experiment when you go home.

find something you want to cook but set the microwave power to its lowest level. it takes about nine hours. it is not get a cookie from the cook you from the inside out. we promise. i remember watching it and saying is the universe expands it gets cooler and cooler. as it expands it gets cooler and cooler. this time for a couple more questions and we will call it a night. i was wondering if it would be possible to harness the hawking regulation hocking regulation as an energy source. it's very faint.

instead of being microwaved its kilometers long. it's so faint it's really beyond our ability to detect it. i know think anybody doubt that it's there there is a lot of reasons that it is there theoretically. i think they would've already gotten the nobel prize. it is predicted. i think no one doubts it is there. this might be a bit complicated. i'm wondering a theoretical sampling. can actually be in the universe and things like this. there is an event that takes an infinite amount of time to form. could we ever had blackhole

with in the event horizon. it's time to follow valuation. and then if you were watching something falling in it would take a long time for it to fall in and they would be sending you a signal saint and actually they're saying things are going badly. and you never see they would never get back out to you. but you can see this process of the event arising and then that was seen.

it actually seen the two event horizons and merging them into making the one and we have the gravity waves to show it. it's happening at that edge. in their limits. in the event of itself. it would take you that there is an entire chapter on the subject. i think it was only 5% of the book. we will go with the sound bite mode the universe is expanded ever accelerating. but presumably at some point

it's get a form enough vacuum space in between everything it's not that it's become becoming electrically charged were as it expands it gets more and more space. and they are talking about that amount or longer the bubbles of actual state may occur. it is an internally fizzy champagne. in the newer universe is performing.

can it expand so fast that face -- space rips. the vacuum energy is going up a time. there would be a big similarity and it looks like it is incompetent. it will give to others in time. you probably won't get ripped apart. you have to go really quick. this question is for a group of students. can you explain how the effect for them causes that.

in layman's terms. we are not the allergist. and it has to do i don't have a detail event to this. it is going in a variety of ways. and there are charged currents that actually set that up in the dynamo effect refers to the process by which that can build itself out. it's not fully understand. it helps that you have molten iron. the day it completely closed out we expect the magnetic field to go away entirely. the mood moon doesn't had iron.

>> i'm 12. does the universe expanded from the center are from the front. and how does that happen. it's just all expanding again it's like the only know about the two dimensions. in the universe is just getting bigger. the space is expanding between the galaxies. there is no galaxy in the is a center more than any other galaxy. since the balloon is expanding in this technology that's the way everything was at the beginning of the universe after that not in any accessible place for any of the galaxies that exist at

what speed does the universe expand app. what counts here is relative speed. we look at it. the more distance the galaxy the faster is moving. the nearby galaxies are moving at only a thousand kilometers every second. we talk about that in some detail in the book. we will take for fast questions. let's say that one for last. >> how many black holes are in this galaxy.

there is only one big one in the center. people argue a lot about how many smaller black holes which may be only a few times the mass of the sun may exist. we know of about a dozen or two dozen but they're hard to see. we talked about it. we can infer about that. the number must be in the many tens of thousands. something to keep in mind is to avoid them. this is just a theory that i made up from what i learned here what is in your basement. do they know what they're doing here. this is how we get the nemesis to superheroes.

as you said before. the stars keep on compressing elements to other wants. and it is a last ditch attempt. so then eventually one of the universes all of the hydrogen therefore does a just and because is there just iron and black holes floating around. the universe will end in exactly the way that you described. all of the gas clouds. note new starts will be made. and as you look up at the night sky they will disappear one by one. never to be replaced again. and we will have an entire

universe of dark holes. this is like the last two questions. in the milky way. they are can occur collide with each other. will our species be interfered with. he is worried about something that will happen in 7 billion years. deeply worried about it. so our species has been around for maybe a million years.

so the species changed on the timescale. what about billions of years. our species will not be around. when they collide the state between at the past right back for each other. they are really not to be avoided very much. it will be an awesome train wreck. and it will be this mangled, tangled mess. we were wondering whether stars would go by. where the allegiance might be compromised. if they come to too close we will remember which star we are supposed to be watching.

it will be a fascinating future. it's about 7 billion years from now. to put that on the smart phone to look up. unless you invent something that enables you to live to see it. the last question. since you can look back in space to think there would be a way to see the earth. if you have a black hole light from the earth could go around the black hole and come back and we can see it again. so fate possible in principle but not in practice.

you see that and they are that many years ago depending on how far away the black hole is. it was a practical answer to that question. would be imagining other aliens in a certain distance from earth where it's only now just reaching them. think of the galaxy that might be 60,000 light-years away. the earth sent out 65 million years ago and what was happening 65 million years ago. dinosaurs were rendered extinct by one of our objects. so if you're 65 million light years away you will be seen t rex croak in real-time. and that would be really cool. can you take one more question here before we go to that young lady.

i have better be an awesome question. everyone's watching. so you mention gravitational waves earlier. and how to black holes emerged to create a single black hole. the europeans are in the process of developing a satellite called it will be 4 million kilometers across and they are trying to look for the mergers of the pairs of supermassive black holes. but the typical a distance that you might expect is even larger. the effect that we measure will be comparably small. that is something that we may have an answer to in our

lifetime but were not there yet. and you ask us how do we each find our calling. meanwhile i was eight years old. there was globe. and they used to be sold in these places called bookstores. and i got interested in astronomy when i was eight. i joined the club. i had been interested in ever since. when i was in high school i was reading a lot about astronomy and i thought it was really cool. i remember telling my dad i want to be an astronomer lease and you can get a job doing that. he was happy to see that i eventually proved him wrong. we have the entire universe to look at it.

he keeps us very busy. i am hugely visible in places like the internet and things like that. some people hear my story and i think it's special or unusual because they're not hearing any of my colleagues also tell their story about how they became astro physicist. my story is common. he got interested at age eight. when i parents brought me. i thought it was a hoax. has too many stars. i've seen them from the bronx. there's 12 of them. so this is a deception it's an entertaining deception. they are not fooling me.