18 know about time. (Before we took it for granted.) From Einstein, we know that time is not what commonsense told us it was. As we ap proach the speed of light, time slows down-like in suspended anima tion, perhaps. But we are far indeed from knowing what time is. This is another long shot in the short run, but perhaps worth taking. We can always blame our troubles on time-if only we had a little more time. 24. Research and development of one world institutions. We need to develop one world language. It cannot be English or Russian for reasons of the cold war. And it cannot be some of the African languages, for the use of scientific terms has not developed naturally with the language. And we should not do away with the other languages either, for each culture has its own unique creative part to play in the whole. ti.. Establishing television and radio stations throughout the world. so that the people themselves will have direct contact with something sponsored by the United Nations for the people. Among other things, the radio stations could give local weather reports and additional practical tips to farmers. This would be another very small step toWard changing peoples' loyalties from their own State to the organization that is to be a truly workable federation of peoples and States. a government with power. Establishing one world currency for all States. Establishing one world post office, et cetera. Establishing a computer bank of all hunan knowledge. It would be programed in such a way that each questioner would feed in what his assumptions are. Obviously American so-called knowledge and Russian so-called knowledge do not always agree. Some sort of income tax for the world organization. And of course the establishment of a world Federal Governinent itself. Perhaps in many cases you cannot get some of the things or steps leading toward a world government without first instituting the world government. The present United Nations is a confederacy of States which depends on trust between States. It is, let us say, very roughly analogous to the Confederacy in the United States before our Federal Government was instituted. A truly workable world Federal Government would be no mere Confederacy of States which relics almost exclusively on trust. Rather, its laws would be binding on individuals, not on States only. The very survival of mankind may depend on the establishment on a world Federal Government soon, not "someday". Sometimes we find what we do not seek. And the wide and easy road to destruction may be found in our time simply because it is, indeed, so wide and easy. Certainly all of us would prefer that mankind not follow the road to worldwide suicide. But we do not always get what we prefer. : The CHAIRMAN. Thank you. Mr. Tandy. You have put a great deal of thought and research into your own statement recommending research. WITNESS' EXPERIENCES IN EUROPE I believe as a part of your compensation or prize, if I may call it that, for your winning this contest you have made a tour of Europe. Ja that correct? Mr. TANDY. That is correct. The CHAIRMAN, Where did you go? Mr. TANDY. We went to Geneva and we attended two seminars there sponsored by the United Nations. One was on prejudice and dis crimination, and the other was on the human environment, ecology. The ecology seminar was preparing for a future United Nations meeting to really do something except talk about the world environment problem. ،܂ I was very surprised with our speakers at the ecology seminar. It is the old problem again. We do not really know that much about the problem. In many cases they said, "We don't know the answers. We just don't know that much about how our ecosystem works." Until we develop these things and we do some study and we get some machines that will give us the statistics on the present situation, and we have some sort of theory about how the whole ecosystem works, and inter-relates, we really do not know where we stand. We may be able to get out of it, maybe even fairly easily, who knows, or we may be in a very bad situation, and maybe it is impossible. But we really do not know. The science has just not been developed very far. The CHAIRMAN. What did they say about preindice? Mr. TANDY. This was a little disorganized, the prejudice seminar, 'I suppose everyone there was against it. The CHAIRMAN. Was against prejudice? Mr. TANDY. Racial prejudice. Prejudice against homosexuals, prej. udice against women, this kind of prejudice. The CHAIRMAN. Who bad a prejudice against women? Mr. TANDY. I think the situation should be that we seek to see peo ple as human beings, and as unique individuals, and this is not always easy. WITNESS' ASPIRATION TO CAREER IN POLITICS The CHAIRMAN. According to the biographical note here, you aspire to a career in politics. Is that correct! Mr. TANDY. Yes. I am not opposed to the idea. The CHAIRMAX. I did not say you were not opposed. It says you "aspire to." You are not really actively interested in it? Mr. TANDY. Well, some day I might be.. The CHAIRMAN. But you are not now. This note may be incorrect. It says you aspire to a career in politics. It was given to me by the staff. Mr. TANDY. I would say that is true. The CHAIRMAN. Have you done anything in politics? Mr. TANDY. The first time I was involved in politics was in 1968. The CHAIRMAN. Did you vote? Mr. TANDY. Yes. The CHAIRMAN. Have you been active in anyone's campaign? Mr. TANDY. Not lately. because I am working with the State of Kentucky in the Health Department. It is on the merit system, and you cannot be involved, supposedly, in politics. WITNESS' WORK WITH KENTUCKY HEALTH DEPARTMENT The CHAIRMAN. What do you do in the Health Department of Kentucky? 18 Mr. TANDY. I work in the environment field, very roughly, Right now we do some air pollution and water pollution control work. Mostly we look at garbage cans, and see if people have the lids on their garbage cans.. The CHAIRMAN. That is a very commendable objective. Where I live, a racoon comes out of the park and removes the garbage can tops all the time. It is a great nuisance in that community. We had to quit putting the garbage cans out. We had to put them inside. POSSIBILITY OF U.N. DEVELOPING INTO EFFECTIVE ORGANIZATION . Do you have much confidence in the United Nations developing into an effective organization? Mr. TANDY. Well, I think you might take a gradualist approach and it might turn out to do something, you know, in a hundred years. But I do not think we have that much time. The CHAIRMAN. You do not. Does that mean you do not have much confidence in its being an effective agency! Mr. TANDY. There would be some sense in which I would not have very much confidence in the United Nations, as I have expressed in my paper, in that sense. ALTERNATIVE TO UNITED NATIONS The CHAIRMAN. I know you raised many questions and difficulties. We have always had those, but do you see any good alternative to the United Nations? Is there anything you would like to put in its place? Mr. TANDY. I think that we are at a stage where our knowledge of the social sciences has not been developed. I think we should be working towards a workable World Federal Government and saying it may be that we have no choice. You see my value criterion was not practicality, the art of what is possible. Politics has been called the art of the possible and that is not my criterion. My criterion is the survival of civilization and, like I say, I do not know whether that can be achieved. The CHAIRMAN. Thank you very much, Mr. Tandy. I appreciate your coming here and giving us your views. Mr. TANDY. Thank you very much. I respect you, Senator Fulbright, very much. The CHAIRMAN. Thank you very much. PHYSICAL REVIEW D VOLUME 9, NUMBER 8 15 APRIL 1974 Rotating cylinders and the possibility of global causality violation* Frank J. Tipler Department of Physics and Astronomy University of Maryland, Cole Purk, Maryland 20742 (Received 6 November 1973) In 1936 van Stockum solved the Einstein equations G-87 for the gravitational field of a rapidly rotating Infinite cylinder. It is shown that such a field violates causality in the sense that it allows a closed timelike line to connect any two events in spacetime. This suggests that a finite rotating cynder would also act as a time machine. Since the work of Hawking and Penrose,' it has become accepted that classical general relativity predicts some sort of pathological behavior. However, the exact nature of the pathology is under intense debate at present, primarily because solutions to the field equations can be found which exhibit virtually any type of bizarre behavior.2. It is thus of utmost importance to know what types of pathologies might be expected to occur in actual physical situations. One of these pathologies is causality violation, and in this paper I shall argue that if we make the assumptions concerning the behavior of matter and manifold usual in general relativity, then it should be possible in principle to set up an experiment in which this particular pathology could be observed. 4 Because general relativity is a local theory with no a priori restrictions on the global topology, causality violation can be introduced into solutions quite easily by injudicious choices of topology; for example, we ould assume that the timelike coordinate in the Minkowski me ric is periodic, or we could make wormhole identifications in ReissnerNordström space. In both of these cases the causality violation takes the form of closed timelike lines (CTL) which are not homotopic to zero, and these need cause no worries since they can be removed by reinterpreting the metric in a covering space (following Carter, CTL removable by such means will be called trivial--others will be called nontrivial). In 1949, however, Gödel discovered a solution to the field equations with nonzero cosmological constant that contained nontrivial CTL Still, it could be argued that the Godel solutior is without physical significance, since it corresponds to a rotating, stationary cosmology, whereas the actual universe is expanding and apparently nonrotating The low-angular-momentum Kerr field, on the other hand, cannot be claimed to be without physical relevance. It appears to be the unique final state of gravitational collapse,' and so Kerr black holes probably exist somewhere, possibly in the center of our galaxy. This field also contains The field of such a cyiino in which t entrifugal forces are balanced by gravitationa attraction was discovered by van Sto kum in 1936 The metric is expressed in Woi Papapetro ds H where form: +dz2) + Ldw + 2M dødt u (1) measures distance along the cylinder axis, is the radial distance from the axis, 18 the angle coordinate, and 18 required to be melike at r = 0. (-x< 00, 0<r<α 01 € 27, -8<10.) The metric tensor is a function of r alone, and the coordinate condition FL M2 =ya has been imposed (units (= -1) It is clear that since g detg,~~31⁄23 is negative, the metric signature is (+++) f all 0. provided H + 0 van Stockum assumes Einstein equations Copyright © 1974 by The American Physical Society. where a is the angular velocity of the cylinder. For r>1/a, the lines constant, constant, z = constant are CTL (in fact, by a theorem due to Carter, nontrivial CTL can be found which intersect any two events in the manifold), but one could hope that the causality violation could be eliminated by requiring the boundary of the cylinder to be at r=R<1/a. Here the interior solution would be joined to an exterior solution which would be (hopefully) causally well behaved; indeed, the resulting upper bound to the "velocity" aR would equal 1, the speed of light in our units (though the orbits of the particles creating the field are timelike for all r). van Stockum has developed a procedure which generates an exterior solution for all aR >0. When 0<aR<, the exterior solution is y = (4a3 R2 − 1)12 ln(v/R), B = tan"'(4a3 R2 – 1)1a [as in the interior solution, FL + M2 = r2, so the metric signature is (+++) for R < y < ∞). We see that causality violation is avoided for aR, but Carter's theorem tells us that it is possible to connect any two events by nontrivial CTL when aR > }. 9 (5) where u, a, k are functions of r only. A procedure developed by Davies and Caplan1 and myself allows the equations R0 to be integrated; the solutions are equivalent to (3). (Details of the uniqueness proof can be found in the Appendix.) Since the causality problems come from the sinusoid factors of (3c), we might hope to avoid these factors by "transforming" (3a) via (4) and then attempting to join the interior field to the "new" (topologically distinct) field. But the "transformation" (4) will not change the exponents of r, which for aR> become imaginary-in fact. for aR, (3a) is (3c) with the substitutions € 13 and = iy. Thus we expect causality violation to occur in the matter-free space surrounding a rapidly rotating infinite cylinder. As Thorne's has emphasized, however, it is risky to claim that the properties of such a cylinder also hold for realistic cylinders. |