A h l Federation of American Scientists For Sunday-release 1621 Street N w - NAtional 5818 May 26 19h6 wthington 6 D Go COMMENT pg BIKINI 13201 1 TESTS It has been stated in the Senate and elsewhere that the atom bomb tests at Bikini are being held to furnish scientific information It is thus implied that scientists are professionally interested in these tests to learn more about the po- tentialities of atomic energy This is not true The tests are purely military not scientific Appended to this statement is a resolution adopted by the Federation of American Scientists at a recent council meeting in Philadelphia in which this fact is stated in unequivo- cal 1anguage Scientists expect nothing of Scientific value and little of techni- cal value to peacetime uses of atomic energy as a result of these tests Whether or not these tests involving the expenditure of millions cf dollars and tens of thousands of man-hours are Justified is not a question which scientv ists are qualified to decide An atomic bomb is a military weapon and when where and how it should be tested are military questions The tests of course are based on-the frightful idea that -- mankind -- might have an atomic war in which navies would desperately seek to survive to de- fend their countries or to attack the enemy 'Scientists seek by education to teach men that they must abandon atomic weapons to preserve civilization but we recognize that it may take an atomic war1x3teach them this lesson So long as they have not learned it the military have a mission fantastic and short eighted though it may seem to reasonable men Scientists are cosperating in these tests at the request of their country's armed forces although they do so with heavy hearts and without enthusiasm They would like however to assist the American people in forming an accurate Judgment of the purposes and results of the Navy experiments we suggest that cor- respondents and newspaper readers should keep in mind the following considerations This statement was prepared by the national officers of the Federation of American Scientists It is based on a special report made to national headquarters by the Executive Committee of the Association of Los Alamos Scientists the men who de- veloped the bomb and made the first test at Alamogordo New Mexico and who are working on the current tests 1 THE NUMBER OF SHIPS DESTROYED WILISNOT BE THE BEST STANDARD FOR THE EFFECT OF THE BOMB Reasonable men should disconnt in advance headlines which may read Fleet Sur- vives Test Only One Ship Sunk Area of damage done by the bomb to brick or steel and concrete structures is about ten square miles Total destruction extends for a radius of about one mile There will be one hundred assorted target ships spread over a radius of miles and the majority will probably not be damaged to any extent But there is no doubt whatever that a direct hit or near miss by an atom bomb will destroy any ship ever made One bomb one battleship Flimsy houses three miles from the blasts in Japan were destroyed but a bat- tleship should be more than fifty times as strong as a Japanese house It is well known that the variation in pressure is such that at one half the distance it is -2 - not more than four times as great and the estimated lethal blast distance is less than half a mile Published reports indicate no serious radiation damage to people beyond one mile Persons below decks and well shielded by heavy steel construction would probably be safe from radiation at a shorter distance Ships closer than one half mile will be damaged but only those closest to the point of detonation will be sunk Few ships will be appreciably affected perhaps ten out of one hundred and probably only one or two will be sunk Dr Hans Bethe formerly director of theoretical physics at Los Alamos who had made some studies of the forthcoming test has predicted that not even one capital ship will be sunk Again it must not be assumed that any conclusions may be drawn from this as to what damage a bomb would do to an American city Cities are not built like bat- tleships See the May Reader's Digest or contact Federation Headquarters for excellent brief popular studies of what an atomic bomb would do to an American city 2 ACTUAL STRENGTH OF BIKINI BOMB BLASTS SHOULD BE ANNOUNCED It is possible for an atomic bomb to be a dud or a semi-dud The Navy has an- nounced that the Nagasaki type bomb will be used in these tests but the actual bomb used may not explode as efficiently as did the bomb at Nagasaki Instruments for measuring this precisely will be in operation and unless this datafis announced at least in part no valid conclusions may be drawn as to effect of atomic bombs on naval vessels We can not here of course discuss future more powerful bombs 5 THE DEEP UNDER mamas TEST OF NEXT YEAR WILL BE FAR moss THAN THE TWO TE st PLANNED THIS SPRING All scientists who have studied naval atomic bombing are unanimously agreed that there is nothing final to be said about the subject until a deep underewater test has been tried The first test will not yield spectacular results the second test will be more damaging but an under water test at an appreciable depth perhaps using something similar to is potentially-far more dangerous to ag entire fleet Even the surface test will give some tidal wave effect and since water is non- compressible a deep sea bombing might have extreme and unpredicted results The Vintense shock produced by the chain reaction is dissipated in air but below the surface would create a sort of monstrous bubble of energy which might buckle the plates of ships several miles distant In this connection it should be noted that even ordinary torpedoes do not wound ships by penetrating but by exploding on con- tact alongside the ship under water h ONE BOMB FOR ONE SHIP e THIS ITSELF IS A REVOLUTIONARY ACCOMPLISHMENT IN NAVAL WARFARE - 4 A battleship costs approximately one hundred million dollars even a destroyer twenty million Dr J R Oppenheimer has stated that an atomic bomb could be pro- duced for about one million dollars It would be good business to spend not one but a considerable number of bombs to sink a battleship and even a few bombs to sink a destroyer In addition it takes many times longer to produce a ship than an atomic bomb an extremely important factor in industrial total war We already hnow then that it is cheap to sink naval vessels with atomic bombs Since the bomb creates a 'ball of fire' approximately one third of a mile across and does total damage for a half mile on either side it can be seen that it does not have to be a direct hit in the sense that ordinary bombs are described as direct hits 5 NONEIHELESS BOMBING A FLEET MIGHT NEVER BE TACTICALLY VALUABLE Despite the economics suggested above it is still possible that bombing a fleet at sea would not be worth the trouble in an atomic war Supposing that man- kind risks suicide by undertaking such a war the economics would still be against bombing ships One square mile of city destroyed atonically would be a loss in the average American city representing five hundred million dollars or five times the cost of one battleship Strategically Speaking when the guided missiles now being developed are per fected Vw2s and other robombs with atomic warheads will arch through the stratosphere far above any Navy even above air forces and so far as present science is concerned beyond reach of any kind of radar detection and defense Scientists assert there is no foreseeable defense whatever against such an attack in a future war 6 WHAT THEN WILL BE THE MISSION OF THE FIBSE LINE OF DEFENSE IN THE NEXT WILL BE THE GOOD OF THE PROTECTING ITSELF BY DISPERSION WHEN IT CAN NO LONGER PROTECT THE HOMELAND THAT IT Scientsits can not know any final answer to this question A proper answer must take into account the full role of the Navy as well as many-relatively minor phases of atomic bombing Even where the bomb might not crush and blast whole ships radiation and in cendiary effects would produce incalculable damage particularly in harbors Water in the vicinity of the bomb and dust particles in the air will become radioactive and be deadly to human beings until dissipated by the processes of nature A breeze containing radioactive particles blown for miles might conceivably result in the death of many sailors on ships miles away from an atomic bombing The pre- cautions taken in allowing personnel to enter Bikini harbor after the bombing may be taken as a fair indication when repair and ship crews might re-enter Pearl Harbor if it were ever atomically bombed W A Chairman Federation of American Scientists Melba Phillips Secretary J Ememeww Appended to this statement Resolution adopted by Federation Philadelphia Council Meeting Statement by Professor Louie N Ridenour reprinted from SCIENCE ILLUSERATED FURTHER STATEMENTS We plan at the conclusion of the Navy bombings to issue a statement from scientists who went to Bikini and further to have available data from individual observers we would welcome inquiries from newepapermen at that time as well as copies of published accounts of their observations at the bombings A-h08 FOR IMMEDIATE RELEASE RESOLUTION OF NATIONAL COUNCIL FEDERATION or AMERICAN SCIENTISTS Washington 6 D 0 NA 5818 STATEMENT BIKINI ATOLL TEST The President s announcement of postponement of the atomic bomb tests at Bikini Atoll we believe will contribute to a more favorable atmosphere for the meeting of the Security Council and the projected meeting of the UN Atomic Energy Commission We feel it would have been unfortunate at this time to focus the attention of the world so dramatically on our military preparations The Navy tests will have a purely military value Scientists recognize that such bombings will not add anything to fundamental_scientific knowledge - they are not significant from the standpoint of development of atomic energy for peaceful purposes Scientists believe that in the atomic ago no amount of military preparation can give as real security If there is another war with atomic weapons we and all the world will suffer irreparable losses no matter who may be the victor We must put all our best thought on organizing the world for peace To this end we urge full support of the United States program for internation- al controls over atomic armaments and for the UN program of collective security as opposed to primary reliance on armed might The great experiment to which this nation and its leaders should devote their greatest attention and energy is under way in the United Nations Organization There we are making the fateful test of whether nations can work out their problems without resort to war - We do not need further bombing tests to tell us that if this larger trial of world order fails the great UN'experiment will end in the most destructive explo- sions our earth has ever seen - BIKINI WHAT CAN IT A statement by Prof Louis N Ridenour University of Member of Administrative Committee Federation of American Scientists When an atomic bomb is exploded a good deal of our precious and laboriously produced fissionable material is destroyed The Bikini tests seem an extraordinary pointless way to destroy it - 5 It would have been wiser to expend these bombs if military demonstrations have to be held in land tests which would be seen by millions of people All but the most unimaginative witnesses would gain the deep conviction held so strongly by those who were at Alamogordo last July that war must be ended for all time Few except active participants will be present at the tests - not primarily as a matter of policy but because of difficulties in providing transportation and grandstand space It would have been useful to test the bomb against-buildings constructed along occidental lines Great publicity has been given to assertions that while the bombs dropped on Japan did widespread damage an atomic bomb would be no more de- structive in lower Manhattan than a lO-ton high-explosive bemb Although this is contrary to the conclusions drawn by competent specialists on the basis of careful observation and experiment some wishful thinkers can be convinced only by an actual demonstration The value of the proposed tests for their avowed purpose setting Navy policy is dubious in the extreme Only a prodigal enemy would spend his atomic bombs on ships Even such an enemy would employ against ships an underwater burst which is not being tried in the Pacific this year for technical reasons A bomb bursting over a city will destroy a square mile and kill 100 000 persons used against sturdy and widely scattered ships it night over destroy one or two and do little harm to others No one should be surprised if only one ship is sunk by the first Bikini bomb An air burst is the least effective way of using a bomb against ships A blast pressure of about five atmospheres is required to do substantial damage to a ship half that will knock over a brick wall and such relatively enormous pressure is not likely to exist beyond a radius of a few hundred yards from the point of explo- sion Within the small circle encompassing the blast there is likely not to be more than one ship The gamma rays which killed so many thousands in Japan will be expended on a few experimental animals whose fate will probably not make the newspapers should it be released The flash of heat which literally cooked those Japanese who were outdoors and within half a mile of the explosion will be wasted Even the thin walls of storage boxes for ready ammunition will provide sufficient heat shielding to prevent explosions hull and deck plating will keep fuel from catching fire The effect of the surfacs burst in the second Bikini bomb test may be greater but probably will not be spectacular The underwater explosion in the third test should prove destructive over a fairly wide radius but there are no plans as yet for this the only really significant part of the Pacific experiment - Though extravagant in fissionable material and the public funds the Bikini tests must not be regarded as establishing any result - not even a scientific result The tests are being held in such haste and under such difficult geographical condi tions that there has been no opportunity for proper instrumentation Even when the Pacific trials are complete conclusions on naval policy must be carefully drawn No sound conclusions can be reached until after an underwater burst Reprinted from SCIENCE ILLUSTRATED