Of Science and Scientists; 9; The Size of the Universe

Why the size of the universe. Yeah. A.

Fascinating site. You have admired it of course on many a starry night. And you've probably thought this look like diamonds. Scattered over a black velvet trough by some immensely rich again. But all this time the list has a delay on the vault of the heavens. Are they not distributed in depth in space. And supposing they way would they be distributed at random like. Always there perhaps an architecture. Wouldn't it be wonderful if they were indeed such an architecture. My past tonight is to tell you quite a bit about the arrangement of our universe. They changed and saw the stylus of the galaxies of this

planet of the sun. How they all live together in the universe but the distances and how they are the latest to each other. This photograph that they have here is probably as good a bomb to start on as any because this photograph the C dot at every dot is a star and the star dots are each of them in the full sense some all of them sounds very much like our own sun Somebody painted some a little brighter. But all suns and of all of that. These little places that we see here these margins they are galaxies that large star systems well beyond our own star system or our own Milky Way system and the star systems themselves at very great distances from us. We shall find that these can be observed to distances as far away as two thousand million light you is really very great distance into space. The stars are somewhat near zero but but before we turn to the

stars let us turn first to the nearest neighbors that we have. Let us turn to our own solar system. The plan that I have to start out is our own solar system and gradually move out from the sun to the planet from the planets out to the nearest star from the nearest stars in our own star system our own Milky Way system to the fire to sleet and out into space to the galaxies and beyond. And I hope to give you an idea as to how these out of date. Now the first photograph that I have here is of a very familiar and basically not very interesting object move all of us see Newble. You know that it is to companion satellite to our own earth. It's not very far away from our US. Its distance is only a little more than 200000 miles which means that at the speed of light on earth an eighty six thousand miles a second life today goes from the earth to the moon in a little over one second. Many of you will probably remember how about

ten years ago for the first time a Diaby but bounced off the surface of the moon detonate our beam signal sent from the earth. Bent towards them will be turned by the moon to the earth took a little over two seconds to complete the hole to what they say is the distance to the moon is about two light seconds a little over that. But now let this lady come to be in full body in our solar system which is the sun itself. Here is a photograph of the some of the some of the familiar sun spots shown in one of two positions. The sun is a star. It happens to be to us the most interesting star because we happen to be very close to it and I know this is one of the planets around our own sun. The distance to the sun is 93 million miles. Now you might say here it gets busy and suppose large figures it out and tells us about distances that are so large that we cannot imagine

that that is just tell you a moment to imagine but 93 million miles is like. Well many of you must have had a car that has a gun. Ninety three thousand miles. My own car has got at the present time more than 86000 so I know just how fine it is to go about eighty six thousand miles and I can imagine very well how far ninety three thousand miles is. Well if you imagine a parking lot face 1000 fire old cars all like mine more or less these thousands of cars will have travel a thousand times 96000 miles which would be 93 million miles. I hope that that will give you an idea that the distance is great but not the distance that you cannot imagine. Now if I continue to talk all the time in terms of distances in Miles the figures would become so large and so one wheel B that it wouldn't make sense. But I haven't eaten the magic in astronomy at distances more in terms of the time that it takes for the light

to cover a given distance. Light moving at a rate of one hundred eighty six thousand miles a second travels the distance that is about seven to eight times around the earth in one second that the distance to the moon in a little over 1 second. It takes 8 minutes to go to the sun. We say data for that the distance to disarm that 90 Slieve million miles is a distance of eight like minutes. Since it will take a likely eight minutes to travel that particular distance. Now we asked what other distances are good in the solar system. Let us look at one of the odd objects in the system and we turn to the biggest them best of all the planets that beheads the planet Jupiter. Many of you have probably seen Jupiter you probably have seen the belt structure which comes in a cold atmosphere of ammonia and methane. These little black spots by the way are shadows. That is so owned by the satellites of Jupiter on the surface of the atmosphere. This planet Jupiter

is at a distance five times as great as the earth from our sun. They are four or five times 93 million miles is the dimmest distance from the planet Jupiter to our sun in terms of like minutes five times eight is 40 minutes. It would take a light day about 40 minutes to go from the earth from the sun to Jupiter. If you move out of planets for example that's the famous planet Saturn. This is beautiful a structure it's a little farther out but it's not really too much about the details of the figures but we can say that the solar system has all its planets is contained at roughly visiting a distance of about 40 of these astronomical units 40 times 93 million miles distance from the sun. That system has some very distant outlying members. The Comets are probably the ones that go farthest out there you see a very fine example of one of these comments the comments that are the objects that coal fired us

out in our solar system and therefore we go up to distances of about 50 times this 93 million miles to from this. And they look at the diagram that gave you some idea about how these arrangement really works. Here we'll see next one of the outer planets Pluto lies beyond that next to you and up here you and this down here. Demi move in from Uranus to the planet Saturn to Jupiter to mine and the earth is this distance from the sun point here today or the next month. That is about 93 million miles. At the speed of light therefore we can say that the dimensions of the solar system copping one across the entire system. I am of the order of about say 10 light hours in other words if you were to start from the earth and right off the bat and go out and learn to visit all the planets and do so at the speed of light it would just take you a full long day's

work and you would be home in time for a late supper. In other words the dimensions of a solar system are measured in terms of light hours that I just notice a few of these things on the blackboard. The first one that I would like to record here is that the distance along the earth. Is. To just stop. He's 93 million that must mean we need 6 0 it means that. 93 million miles. That is equivalent to eat. Light. Minutes. A second bomb. That the dimensions of the solar system. So we go. So would a solar system. From one end to the other.

In about say a valve. Like ours so moving at the speed of light. Fowle ours to go through the solar system. That. Gives us our. Basis for discussion. We know how far that is now from dealers to the sun but the dimensions of our solar system. And now we turn to the system of the star in this very fine photograph that I have here. You will see a section of our Milky Way. It happens to be the section of the Northern cost of seconds. Those of you who know your stars may notice dinette RPA LBO the end of the COS is just off the photograph. Here we have the cost bar in this photograph. You see a great many dots and you'll remember from the early Obama that every one of these dots is a star that every star and again is a sun and that the sun's tires are in many cases where the

sun. In other cases in principally faked or in other words our sun is a beauty and for that sort of a star then we ask about distances to the star dots here they've all come out something of the Order not the light minutes. But they're measured in terms of light years. Let me first of all the Mind you that's been asked a dimension of the solar system is measured in terms of light hours Bellfield the blackboard that the distance to the nearest star. So from our sun and the planetary system to the next star is four light years. The first thing that we notice about the universe is that it is a very big and empty place. Here we have is our solar system about 12 light hours you've got to travel at the speed of light for four years to reach the nearest star. When you take an evident style dot here in this photograph the distance off that star is not four light years but more likely 4000

light years. We see definite that there's a that if a depth to the space that we have that is look at this photograph a little further Far from it we can be begin to see some of the basic features of the structure of our Milky Way system as we come from one corner of the photograph and move slowly closer and closer towards the center become to more and more stylish regions you will find that generally everywhere in the sky. If you look at the band of the Milky Way in the sky that can see the scene very beautifully at certain times of the year. Then you will find that the bend of the Milky Way is a region of high star concentration that are more stars. If you come from a distance and go towards the Milky Way in the Milky Way and at some distance away from it. In other words it looks as though the Milky Way band is a real band of star a constant glacier. We find that the stars in the Milky Way and at many different sorts of distances. So

some fired in a way in other words the Milky Way has great depth. Our sun is a star near the central plate of a large system of stars known as the Milky Way system a highly flattened system as we can see go at right angles to it than a few stars in the plane. Many stars indeed. Here we have a section in the Milky Way. Let me draw attention to two out of each one of them. This little Nebel called the North American Nebula for obvious of these here you can see almost the front of a canal the Gulf of Mexico Cape Cod is mistaken here to the coast of California that this nebula is made out of gas. It is gas that floats in between the star because for ever these three games that we have in the region around the sun in terms of all sorts of matter two grams are squeezed into stars in the sun the other gamete left to float flee as gas and dust in-between decide this dust is shown for example here in the Gulf of Mexico

or the Pacific Ocean or the Atlantic. Tiny little icicles that float in between the stars. Now let us have a good look at the Milky Way by itself. The next one shows you the outline of our Milky Way check the member that head this region up here enough photograph. We know already that these clouds are not really clouds but they are really startled the effects of a great many stars coming close to get in the Milky Way. We know that the constellation of stars increases as we go from the outside towards the central band. We noticed something else some pirates are exceedingly like this one up here near Scorpio and said to tell you another part the part that we see from our latitudes in winter near here. Tell us and Orion that fire is very much thinner. But this is the case. Let me look at this photograph we see here. Certain parts are very black and blue

like this pirate that you see in the summer Scorpio secretary. Other pirates are very much weaker like the pirate in town was the bull and you know I am that you see you know with the Milky Way. Why is that. Simply because we are in the central plain of the system but firing away from the center that so let us have a look at some more of these gas clouds of the Milky Way. Because we shall find that day the clouds like this up here. They've really given a general outline of the structure of our system and especially delineate where the spiral features out in our system. The dots here songs again the guy is shown as white beautiful clouds. The little things like this little black hole here the keyhole nebula we call this they are produced by the cost of dust. The Milky Way system if you could see it from the outside it would probably look something like this system up here. Probably living in a point in this life style system

like the one surely here by the black metal. Our point is awfully about twenty seven thousand light years away from the sun the day I met the love the system approximately 100000 light years a few years ago. Mrs Bock and I drew a diagram of our Milky Way system and it still says flitting about to show you what dimensions are involved. The only thing that we need to do today is that as a few years ago we thought this was a scale of one hundred thousand light years it is now more likely that this is a present 80000 light. But if you take that one connection this gives a good picture. Looking down on the milky way the sun here the center of the Milky Way here a distance of twenty seven thousand light years 100000 light years roughly from one end to the other seen sidewise. There you have the general picture of our Milky Way system. One final point. The Milky Way moves around the long dates around the

center. From here today after that the seven thousand light years be more with a speed of one hundred and forty miles per second. That means value I say want to disarm the earth and everything that it has gone. One hundred and forty miles. How long does it take us to go one side out just one second. About the next gospel show what do you get will see that it will take you quite a while to complete one circuit two hundred million years. So long galactic evolution takes place in two hundred million years be called that often one costs MC. This will give you an idea of the men the size of our Milky Way system. So much for the Milky Way. That is right a few of the facts on the blackboard. First of all that the diameter. Of the Milky Way system. I did this M-W system

is about one hundred thousand light years. Let us write up the next thing. The distance. Song to send. Is twenty seven thousand like us. And the distance to the nearest star dissidents some to the yellow star. Is for life. Then we have sort of the facts of life. Yes they affect the stars and that's the effect. The Milky Way system and now in the final few minutes let us get out into the universe of galaxies. If you galaxy is probably is a spiral galaxy just like our own system is like the one that I have shown you already. To give you an

idea of it that this be a typical Milky Way system 100000 light years from here today our song twenty seven thousand light years from the sun to give you an idea of the arrangement. Let us just take these Milky Way systems and suppose that all of them at the same dimensions as our own saw might infect a little smaller but that is beside the point. The important question to realize is that these systems are left fully about one million light years away which in other words means this that if we want to build up the universe take a series of these disks make each of them a hundred thousand light years across put a million light years apart and then flown them out in space like they're doing here. There they go. Be sure they state a million light years apart. Keep it up for something of the older off of about thousand million light years. Two thousand million light years and you have the universe of galaxies. Now there is the universe. Let us have a look at it and see some of the things in a

little more detail. Here goes one of these galaxies much like our own probably spiral structure. God das all the venue sings in a show not on nicely in a photograph with a 200 page telescope of Mt.. Palmer the show you are not alone that we see Edge on in rather than face and there you can see again the central biologist at the head. Our song will be in a position like this. This black belt in the middle is produced by the cosmic dust that shields off the light from the more remote objects that it looks to let some out of us then we will find out for example that one of the most famous of all is to famous and the guy with our galaxy you can see it faintly in the sky as a faint star sometimes is a little bluer when you see it in a photograph you see the spiral structure coming out in it you can actually photograph with the big telescopes. The individual stars in a galaxy your Milky Way system of that. So this one is probably a little bit bigger than the one

that we have had all that. Let's look now at some to have a slightly different structure like this one up here where we come into Iran that is in regular in shape. This is a satellite galaxy of our own Milky Way system. The Large Magellanic Cloud but you see it out a common components of gas Styris and dust that I have a blast. Now let us finally say how far can we go out here this one a photograph of a really distant goal here of a coming in terms of distances of 10 million 30 million 100 million light years and bigger that is really moving out in space. Finally Thembi come to the real distant ones you'll find that we come into distances that are still far greater the find for example that are some that are received from US based IF expedience at Vandy Vanny fossil of the order of about say this one here 20000 kilometers per second that is about 14000 miles.

Some have been measured this speed five times as big. This dish to be has a distance of about 100 million light years. The gator's distances for which this expansion effect has been measured. But on this high as about 500 million like you. We go beyond that the faintest galaxies that beacon photographs have probably two thousand million light years away. Well in the last minute let us do it right to the blackboard and see where we are again. And here we have a picture I'm starting now. We might almost say from the bottom up. And I remember that the galaxies measured about 100000 light years across some a little smaller some a little bigger. Let us remember too that the nearest star is even still four light years away from us. The member that these galaxies at these dimensions had about 10 times as far apart as there they are with us that they go up to distance us as great as hundred or two

thousand million light years Camembert to that indies like us that light goes around the Earth seven to eight times in one second eight minutes to the song 12 hours of the solar system. For years the distance to the nearest star 100000 like year for the galaxy and there we have about the story of our universe as far as dimensions are concerned. You shall some day in a beautiful photograph. They were not taken just for the sake of their beauty. They are one of the most effective means by which the astronomy again space science information about the universe of stocks. The estimate makes measurements on these photographic plates. A 30 seconds of an inch on one of these plates corresponds to an angled much smaller than what the scientists could measure with the most accurately made mechanical device. Then using these measurements.

Yes Tom I'm a finds for example the distance of the earth from some of its nearest neighbors. The work of the astronomer has much in common with that of the other scientists. Each group of scientists has its only since he's own enthusiasms. The physicist has his own idea of the beauty of physics and unfortunately that is not a kind of beauty which is obvious to the non physicists on the continent. The overpowering beauty of the things you've seen is just as happened to you as to the astronomy. Another diving for even more important to the gastronomy than beauty is the intellectual challenge of his work. He like other scientists has an intense curiosity about his feet and the understanding of it he obtains in places its beauty for him. The estimates work is a continually given date between astronomy

and the obvious sciences. You make shoes of optics and mechanics in the design of his telescopes electronics is for him a basic tool by means of chemistry he finds out what elements exist in this stuff and in turn why less Ptolemy makes use of the latest advances in the sciences. It presents to them the most fascinating and awarding problems. For instance events at this surface and instead of stops takes place at such very high temperatures and pressures that we know almost nothing of the behavior of matter under such extreme conditions the urge of understanding they wind of such an astronomical to be on says less pushes the chemist and the physicist into the regions. Objects time lay high pressures and temperature combine which he might not

otherwise have felt compelled to investigate in this give and take between the sciences. It seems to me that US Tanami has given mall money to house AC. It has brought to light this all important tools. Nature is want the laws of dynamics the laws of physics and chemistry of the same whether they work here on Earth. All fountains of millions of light years away from us in the depths of space. This it seems to me is one of the most important facts which has been named passed on ness by the work of the estancia. This is National Educational Television.