Century of Science; Why Study Stars?

This sound is called a whistler. It is produced by lightning and heard by a radio telescope. It is one of the sounds of science in the 20th century. WGBH FM in Boston and presents a century of science produced under a grant from the Educational Television and Radio Center in cooperation with the National Association of educational broadcasters. This is an exploration of developments in 20th century science and of the implications they present for contemporary American society. Your host voted Tory former editor of Popular Science and now director of radio television programming for the Massachusetts Institute of Technology. Few men are as well qualified as Dr. Harlow Shapley to talk about the century of science. He's been one of America's most distinguished astronomers and a leading spokesman for scientists for many years from 1921 until 1952. He was director of the Harvard observatories is a former president of the American

Academy of Arts and Sciences at the American Association for the Advancement of Science Professor Stephanie you've seen a great deal happen. How have men's ideas or concepts of the universe changed during this last half century. They've changed enormously I would say in many other fields. Our store of information is at least double what we knew up to all times before 1900. We can say that for the fundamental ideas in science as well as for shall we say the returns of practical research. Well for instance the one that comes to mind I suppose is theory of relativity. That is all of this century beginning in one thousand eight hundred five when the special theory came along and when Einstein came out with that most pregnant. And simple equation and the whole field of science namely equals MC squared. He had his energy is equal to

matter times the vaastu of light squared. Let me interrupt you just a moment. We all hear that has been applied in atomic matters but no is just how did the astronomers of stars galaxies or it change in a very fundamental way. This equation that I still consider the most important one in a. World next to two plus two equals four which is the basis of logic in astronomy. The effect solved tremendous mystery. You know the sciences react on each other and we attack many of our problems now from diverse directions. And it might surprise you to know that thanks to this particular equation that I mention to this special theory of relativity deduction why we can make a subject like paleo botany tell us about the internal structure of the stars. What is paleo botany. That sounds far fetched edible paleo but he means it botany of the geological ages of the past

eras and in recent times we have found that we find green leaves operating. Thousand five hundred million years ago. That is a billion and a half years ago. But what is a green leaves mean. It means that the sun was sending out light and that chlorophyll was in operation and what we call photosynthesis was operates even as it now does in the cornfield to give us food. This operation of a billion and a half years ago showed the sun was at least that old. It also showed the sun was about as strong as it is now and about as strong a light in the same as all the way through the geological ages. When we lay down the cool measures those ancient ferns of 300 million years ago they were doing. What I call Operation chlorophyll namely the photosynthetic reaction that is using the light from the sun and the stars too. Fix carbon for the plants. So we depend wholly on the food we can get in that way from sunlight. And that is where paleo botany comes into the picture. In effect you look into the earth to say yes we

look into the fossils and the earth has no more to it than what I have said. The sun could if it were just a hot body cooling off keep us going say for about 15 million years. I mean we could still have a hot sun but only 15 million years but these plants are 10 times out or 20 times out old and therefore we have to find some other source of energy and that force the astronomer to look into the atom to see if there could be the source of the energy that keep the sun photostatic you might say thermostat it throughout all these millions of years and there was where we came across the suggestion and 100 for that may be the source of energy that operates now from the sun and has for such a long time came from the transformation of matter into energy. Then came Einstein's equation equals MC 4 and we saw what the relation was. And so we could compute that the little change over the evolution of matter say from hydrogen into helium would provide the radiation we needed to keep

the sun going. This is maybe off the track but is the formula for the release of energy and the other stars the same as in the many ways in which it is believed that this could be. They all are the same in the fact that the energy comes from the changing of hydrogen into helium. But how that changes done varies somewhat. For instance in our hot star like the dog star we call it Sirius and that star the source of the energy is the burning of hydrogen fuel into helium. By way of the atoms of carbon nitrogen and oxygen we call it the carbon stored mechanism. But in our sun and stars like our sun that changes probably not involving carbon but going by the way of hydrogen and heavy hydrogen and getting into helium in the same way. But all of them make use of that traps mutation of matter into energy.

And this would be true. I've heard your middle name is galaxies so I'll ask you about those two of the stars and other galaxies too far as we know is true in other galaxies but for this reason we say that we haven't been there of course because they're pretty deep in space because we find that the chemistry of these other galaxies the chemical composition is the same as ours. So the physics is the same the same laws of gravitation and radiation. Therefore there's a uniformity in the nature of the universe all over and what we say we find here we assume and believe. Definitely holes elsewhere. So we're all using this hydrogen into helium operation. Well Dr. SEPA you have mentioned these different ideas. How big is the universe believed to be or is it infinite. That's a hard question to answer and one that has at present no definite answer. I remember I asked the great thinker on the subject Albert Einstein one time whether he would be inclined to say whether the universe is finite or infinite. His answer was a shrug. In other words he didn't want to

decide that we had a finite or an infinite universe. I think most of us would go along with Sir Arthur Eddington and believe the evidence is stronger that the universe of space time. I put those two words together. Is a finite universe with a finite amount of matter. I mean you could specify intones amount of matter you can specify the volume. That seems to be a little more satisfactory but still it is not computed. Definitely there's one theory about the universe at the present time called the continuous creation. There was suggest that in time it is infinite back words and forwards and that space is infinite and perhaps of the masses infinite. It isn't clear. But that's just a gamble. That's just an exploration. It is hardly astronomy as Morse will say semi philosophy. So I think I can't answer that particular question whether we believe the universe is finite or infinite or if it is infinite whether we mean it's infinite in mass or just infinite in extent of space with a universe expanding within it. The one thing we know definitely is that we have. Around us literally

trillions of galaxies and they're scattering. Therefore we have what we call an expanding universe. I mean they're becoming farther farther apart. There are fewer of them per cubic light year but just recently there has been some results from other polymer telescope that indicate that maybe the universe is not expanding as rapidly now as it did a billion years ago. And that would lead to the suggestion perhaps that our universe is pulsing that it is getting bigger scattering now. But after a great long time it will come back together perhaps in fifteen thousand million years. That is one possibility and one little fragment of evidence that points in that direction now have the changes in the first place result pretty largely from equations and thoughts like that I had the impression it came more from instrumentation from the development of bigger telescopes and better techniques. You're right I've referred to theoretical deductions and mathematical operations in

that particular field. But even so they had to be based on observations. Well the fossil leaves and of course the rate of radiation of the sun and the nature of sunlight that can be observed. So the observation has to go along with theoretical interpretation and in general is more important. Do you foresee that a lot more will be done with present instruments and techniques. Or will we be developing new ones. No we'll do a great deal more with the present techniques because they are a recent development they haven't been extensively used and I'm referring se to photo sales and to radio astronomy and to Geiger counters and electron microscopes all through the sciences we have instruments devised now in operation. They have not been fully used and so there are centuries of examination and study and interpretation with what we now have. But of course we are going to develop further. I read somewhere recently that there probably would not be any more

telescopes larger and more built that is optical telescopes because the telescopes of the future would be radio telescopes is that at all likely. I think it's very likely but not because of the radio telescope so much but because you can gain a great deal in knowledge of the universe with the accessory instruments and not the primary light gatherers. If you would build say a 500 inch telescope of glass. At expense of a several hundred million dollars you would gather more light but also you get more light by just waiting for the light to pile up. And so there isn't so much need for a greater one we're glad to have the one we have but a greater optical telescope isn't necessary nearly so much as a development of the accessory equipment. The spectroscope the light measures light counters and various other gadgets carry the same instruments to use and other rights as research in physics and chemistry to astronomy.

That's right now the radio telescopes have come into the picture they've taken a little of the gloss excitement off of the big pale telescope on Mt. Palm are because the radio telescopes are still bigger in Aperture. There are enormous for instance at Palomar telescope is 17 feet across the mirror. Well out of the harbor observatory for several years we've been using one that's 25 feet across. A radio telescope one of the biggest operation in America is 60 feet across that's also at the heart Observatory. And those dollars goes do a marvelous job in the kind of thing they're suited for namely radio waves and radio radar astronomy. Perhaps we ought to explain a little to the differences here. I think that one is the better term for what I think my definition would be the one that would be generally accepted that a radar operation is where you send a message out and get a message back. That is you send a signal to the mone and you get a faint signal return from the moon. In other words a reflection of the radar is used for instance to study the shooting stars up in our own atmosphere and to study

thunderstorms in our atmosphere so made a logical tool. The radar is the radar and astronomy has been used so far mainly for shooting stars in our own atmosphere and for reflections from the moon surface. Whereas radio is what you might say one way radar. It is the radio signal coming in from outside the sources outside. And the radio signal comes to us without our sending anything out at all. And those radio signals come from very great depths and they're used in very many phases of astronomical research. I might add that radio astronomy is really an entirely new branch of astronomy and I'm about as important as a foot Tom a tree that's measuring the light of stars or astral metry measuring their positions or astrophysics studying their chemical compositions and their spectra. And this particular branch of his diamond knowledge come in is awaken enormous interest all over the world. Well then we have some moons of manmade going around the world will help the astronomers but they'll help the Stormers in various ways

and one way the length of time that they can stay aloft. Even though in the outer edge of our atmosphere will give us information about the density of our atmosphere. We already have found that the density the amount of air per cubic inch. When you are up a couple hundred miles is more than we thought it was from other information. So they'll help a bit to tell us about the atmospheres of planets planets. Oh yes by inference by analogy. Oh I see the analogy. Because after all the Venus about the same mass as ours a planet is and is about the same distance from the sun and we can study something about its atmosphere and by studying about our own atmosphere what it tells us about the comparable things elsewhere. That's the way we use in studying galaxies we study our galaxy to find out about others. We study star clusters to find out about other star clusters. Well would it be feasible to put either an optical or radio telescope in a satellite of the earth.

Very practical and no doubt it will be done. A telescope are what it mounts to telescope recorders of radiation in various ways. For instance our satellite as originally planned certainly would pay with a number of instruments to tell about air pressure. The density of cosmic rays the number of little meteors. Oh to ultraviolet radiation from the sun and all of that will be sent back by what we call tele metering devices namely little radio stations even as now from many places United States we send up weather balloons with equipment they keep reporting back what's going on so we don't have to go along we'll. You really don't get very much closer. Will you have a satellite up 500 miles above the earth. That's still a very small fraction of the distances you talk about as an astronomer. Does that make a material difference in your observations. The nearest it brings you'd say to the moon or the sun or to the stars is if you animate nothing. We ignore that completely. The advantage is you're getting above our

trembling atmosphere and so to have a satellite up a few hundred miles the atmosphere with all of its deficiencies. It's dusty and his wavering is behind us and you get a good clear picture. Already we have done one rather outstanding thing that is too little known perhaps and that is we have set up a telescope hanging down from a balloon. Eighty thousand feet above the earth. And that telescope was so far above most of the trembling atmosphere that we got better pictures of the sun service and we ever had before. And we must go on continue that particular enterprise. We might with such a telescope as very expensive very difficult. But with such a telescope hanging from balloons which if that's correspond crackly to a platform in space you see a new satellite or a Tory. We may get better detail of the surface of Mars and resolve the problem of the can now so called the markings on Mars. And the whole trick of course is to go up in order to give above the trembling atmosphere and

in some parts of our astronomical field to get above a barrier which is not very dense at all. And it isn't quivering much but a barrier called the ozone barrier and that ozone barrier shuts us off from knowledge of the ultraviolet radiation from sun and stars. And if we get up say 50 miles above the earth's surface we're above the place where this ozone which is a form of oxygen. Blocks things. Well is there any real point in talking about space travel or you only work on space travel. Space travel by that would you mean getting enough time to get VR and getting to Mars. That's all right. I actually you know after my funds are being spent and of course it is my funds and yours and everybody's funds. I think there are great many other things that would help humanity more than they're spending the many millions many millions billions of dollars necessary to get the equipment for space travel say to Mars. It can be done. I don't think there are any

unsolved basic scientific problems that we don't know how to handle. It's a matter of engineering and of technology. What areas do you feel call for the great expenditure. The big push I had to tackle the tyranny of the unknown as I call it in many fields. For instance there's a great deal to be done and public health in the handling of disease guaranteeing ourselves against microbe invasion on the whole race that my limb and all of us. I think there's a great deal to be done about the interior of the atom the structure of matter. I think it be more important to solve some of the problems of the expanding universe and to just get around on the other side of one little moon around one little planet near one I would star in one galaxy to anthropocentric to work on that. But I'd say in medicine and in physics and in chemistry Well even that delightful problem on the origin of life on the surface of planet that be worthy of much expenditure just to solve the little problem the problem of how did life get started is the

natural phenomenon or there's something miraculous about it. And great advances are being made now that I would like to see much more worked on that and on working on the moon. Nevertheless I am in favor not of the moon so much but of getting telescopes above the atmosphere above the ozone layer in order to solve some of the problems that otherwise won't be solved very well like a Martian problem. Details of it surface. Or maybe the slight changes on the moon a slight change maybe moonquakes a U.S. comparable to our earthquakes and a person might in one way or another make advances in other words what you might learn from the moon or from other planets or even by observing other galaxies could be helpful in solving certain problems are quite real and close to those close to us in one sense not now material well-being clean food and shelter. But for the human mind for instance we have ahead of us a gentle exploration of the problem. Where is man in the universe where he

is in the universe of space and time and matter and energy and life. Maybe even thought. And that is a great field for exploration I've been working a good deal on that I've written on the subject of man's fourth adjustment. I was just about to ask where is where are we at last to say because he's confused. That's a big but he has been objective enough to get some very positive measures about one thing and another and about 3000 years ago he devised the concept that the earth was the center of the world. That not his belief was the center of the world. Not lost in the center of the world you see but that the center of the world said was the center of the earth and we had what we call the geocentric hypothesis. I call that the first adjustment of man to his position in the world. Then the second adjustment came with the Copernican revolution. When we said it wasn't the sun going around the earth is the earth going around the sun and we develop the Sun Center hypothesis or the heliocentric were steam centric then heliocentric then about. 40 years ago

came the other switch in to big electro centric universe it was then discovered and I had the good fortune to be around could play a considerable part and it was then discovered that the sun is not the center of the Siberia world of the whole stellar system of the universe as we know it. The sun isn't the center the center of our galaxy is twenty five thousand light years away in the direction of the constellation of Sagittarius and we man the proud animal that tries to interpret the world and puts himself up so high finds out that he is around one average star at the edge of a galaxy galaxy is a great system of stars. We also about the same time began to realize that all these nebulous masses we see in the sky are other galaxies. So we made the tremendous jump of finding that man was not in the center of the universe the earth wasn't the universe the sun wasn't a sun of the universe even our galaxy it was not necessary in the center but the center of our galaxy is way off when all that is of considerable contribution. So I say of raw material to a man's philosophy to man's religion to

realize where he is in the universe. So the third adjustment was getting man properly at the edge of his own galaxy. Then the fourth adjustment. Which I think is pretty important is for man to realize that this origin of life is such a common operation that probably you can't see the only life is here on this planet. But life is distributed throughout the whole cosmos. Well do you have any evidence of life anywhere. You mean have I been then shaken hands with the mayor. No I haven't shaken hands with the mayor but I've done something the more I've put applied the thought to the situation and looked into the probabilities and there a good deal better than bad observations go as the probabilities and I think it's getting to be generally accepted that life is commonly spread throughout the universe. I mean in a hundred million places where the planetary condition could easily excel and one reason for that is that now we know which we didn't know 40 years

ago that there are at least ten to the twenty of power. Stars that could have planets and 10 to the twentieth is one with 20 zeros after you put that in words maybe it is a hundred thousand million billion stars. They could have that could have life could have planets without great probability then it isn't all likely. So the only place that living would appear would be on this particular planet at the edge of one galaxy on the other. It seems to me that life is here pretty much as a result of a series of chances this must have happened. This must have been nearby or something of that sort if there is we can piece it together. So the probability is that there would be life here soon to be one in quite a large number of very large number a large number if you want to remember that within relatively short astronomical distance from the sun are at least a hundred thousand other stars just like the sun

like the sun in their chemistry and their size and their total and all of that kind. All those things and would you deny those stars at long time or their planetary development Well far be it from you know I don't know. Astronomy still is challenging and fascinating a subject and as it was when you first took it up Dr said Well much more so. Largely because of the development of so many accessories and also because we have bravely gone into some of these problems like the origin of life the origin of planets the age of the universe. Well is there a shortage of astronomers as we hear there are shortages of other kinds of play or do you think we have enough astronomers. We don't have quite enough but we have nearly enough for the positions that are open. America has more astronomers than any other country. We have more big telescopes more research programmes I conjured up one time for the prime minister of India that we had 35 different places in America where we are doing research and astronomy. India India they were to

have nearly enough astronomers but there are few more positions than we have astronomers and the coming of radio astronomy has dug into that particular kind of a student a man who had both astronomy and electronics very heavily and I suppose we could place a dozen such now but compared with the overturned the demands in chemistry and in physics astronomy is a small subject to what extent is astronomy involved in the International Geophysical Year which is very much in the news. What a way the straw me rather started the Geophysical Year in 1882 they had their first so-called poor year where they measured various things including the longitudes that's a part of practical astronomy. The separation of England from Canada. And they measure glaciers and measure the atmosphere. Then 50 years later in one thousand thirty two they did the same thing on a bigger scale but then included something that meanwhile been discovered namely the ionosphere the radio roof and so they observe that throughout the year and then 25 years later all inside of these longitude works and upper

atmosphere work. We had this Geophysical Year that involves 11 different disciplines one of them being astronomy. Now the astronomy part of the Geophysical Year is roughly the study of meteors that is the dust grains that plunge into our atmosphere and burn up and we call them shooting stars. Studying that very intently all over the surface of the earth is one of the astronomical projects Another one is the study of the Southern Lights and Northern Lights namely they are Rory because they are incited by radiation from the sun. Another is of further testing of all the relationships between Sun and Earth. Not only like the Oh Rory but like disturbances that come on radio waves and upset our land lines of telephonic communication. Another one is to study for the size of the various continents. Latitude and longitude determinations are all astronomically all involved in the Geophysical Year and there probably would be astronomical touches to some of the other things like the circulation of the oceans you

see in the circulation of the air. If you were a high school student with stars in your eyes as you say some people have them. What courses would you study what what is the best beginning preparation for a person interested in doctors. Those are two questions What I would do if I had started my eyes well I probably would study stars to the exclusion of other things. But the best preparation to do some star work later would be strange enough not astronomy. No no keep away from that. Because mathematics atomic physics. Chemistry bit of geology and especially a good deal of language now that applies not only to high school but the first 20 years in college. After you got your basic in mathematics and atomic physics and in spectroscopy in the things you get around the physical laboratory and if you can pick up some geology and chemistry then you can go around and see astronomer and ask him what is a subject matter of astronomy and it doesn't take long to get on to it. In other words astronomy

needs so much heavy preparation in these other sciences that it's almost best not to plunge into it prematurely. Of course people life to it. Well thank you very much Dr. Seppi for telling us this about astronomy. You have been listening to why study stars with Harlow Shapley Paine professor of astronomy emeritus at Harvard University and former director of the Harvard Observatory. This has been a part of century of science a recorded exploration of developments in science and their import for the twentieth century America. This series is prepared by WGBH FM in Boston for the Lowell Institute cooperative broadcasting Council. Your host Volta Tory former editor of Popular Science and now director of radio television programming for the Massachusetts Institute of Technology Director for the series Lillian Amber seen all. Producer Jack Dee Summerfield Bill kept misspeaking century of Sciences produced under a grant from the

Educational Television and Radio Center and distributed by the National Association of educational broadcasters. This is the end E.B. Radio Network.