說明 Einstein-Roosevelt-letter.png	English: Scan of the letter sent to U.S. President Franklin D. Roosevelt on August 2, 1939, was signed by Albert Einstein but largely written by Hungarian physicist Leo Szilard . For more information on the letter and its context see its entry at the English Wikipedia .
出處	Franklin D. Roosevelt Presidential Library & Museum 4079 Albany Post Road Hyde Park, NY 12538 http://www.fdrlibrary.marist.edu/psf/box5/a64a01.html http://www.fdrlibrary.marist.edu/psf/box5/a64a02.html
著者	알베르트 아인슈타인  (1879?1955)          다른 이름 아인슈타인; 알버트 아인슈타인; Albert Einstein 說明 獨逸의-미국의 物理學者 He became famous for developing his theory of relativity, especially the equivalence of mass and energy, expressed by the most famous physical formula of the world E = mc². 出生日/死亡日 1879年 3月 14日  1955年 4月 18日  出生地/死亡地 울름 프린스턴 作業 時期 1900-1955 作業 空間 취리히 , 스위스 ; 베른 , 스위스 ; 프라하 , 오스트리아-헝가리 帝國 ; 베를린 , 獨逸 帝國 ; 패서디나 , 美國 ; 프린스턴 , 美國 典據 統制 : Q937 VIAF :? 75121530 ISNI :? 000000012281955X ORCID :? 0000-0001-9183-9538 ULAN :? 500240971 Open Library :? OL3175986A WorldCat creator QS:P170,Q937

Sir:

Some recent work by E. Fermi and L. Szilard, which has been communicated to me in manuscript, leads me to expect that the element uranium may be turned into a new and important source of energy in the immediate future. Certain aspects of the situation which has arisen seem to call for watchfulness and, if necessary, quick action on the part of the Administration. I believe therefore that it is my duty to bring to your attention the following facts and recommendations:

In the course of the last four months it has been made probable - through the work of Joliot in France as well as Fermi and Szilard in America - that it may become possible to set up a nuclear chain reaction in a large mass of uranium, by which vast amounts of power and large quantities of new radium-like elements would be generated. Now it appears that almost certain that this could be achieved in the immediate future.

This new phenomenon would also lead to the construction of bombs, and it is conceivable - but much less certain - that extremely powerful bombs of a new type may thus be constructed. A single bomb of this type, carried by boat and exploded in a port, might very well destroy the whole port together with some of the surrounding territory. However, such bombs might very well prove to be too heavy for transportation by air.

-2-

The United States has only very poor ores of uranium in moderate quantities. There are some good ores In Canada and the former Czechoslovakia, while the most important source of uranium is Belgian Congo.

In view of the situation you may think it desirable to have some permanent contact maintained between the administration and the group of physicists working on chain reactions in America. One possible way of achieving this might be for you to entrust with this task a person who has your confidence and who could perhaps serve in an inofficial capacity. His task might comprise the following:

a) to approach Government Departments, keep them informed of the further development, and put forward recommendations for government action, giving particular attention to the problem of securing a supply of uranium ore for the United States;

b) to speed up the experimental work, which is at present being carried on within the limits of the budgets of University laboratories, by providing funds, if such funds be required, through his contacts with private persons who are willing to make contributions for this cause, and perhaps also by obtaining the cooperation of industrial laboratories which have the necessary equipment.

I understand that Germany has actually stopped the sale of uranium from the Czechoslovakian mines which she has taken over. That she should have taken such early action might perhaps be understood on the ground that the son of the German Under?Secretary of state, von Weiszacker, is attached to the Kaiser-Wilhelm-Institut in Berlin where some of the American work on uranium is now being repeated.

View Roosevelt's response of October 19, 1939

The Einstein letter was published in 1945, as part of the Smyth Report , without a copyright notice. It is thus in the public domain in the USA.

이 著作物은 1929年에서 1977年 사이에 美國에서 出版되었으며, 著作權 標示가 없었기 때문에 美國에서 퍼블릭 도메인 입니다. 仔細한 內容은 虛틀 차트 와 公共 藝術品 "出版"에 對한 仔細한 說明 을 參照하시기 바랍니다. 이 著作物은 美國의 著作物(著作者의 死亡日 基準)에 對하여 短期 保護 期間 條項 이 適用되지 않는 管轄 區域에서 如前히 著作權 保護 對象이며, 캐나다( 著作者의 死亡 以後 50年), 中國 大陸(著作者의 死亡 以後 50年, 홍콩·마카오 除外), 獨逸(著作者의 死亡 以後 70年), 멕시코(著作者의 死亡 以後 100年), 스위스(著作者의 死亡 以後 70年) 및 그 外의 條約이 있는 國家들에 對해 注意할 必要가 있습니다. ???????   ? беларуская (тарашкев?ца)   ? ?e?tina   ? Deutsch   ? Ελληνικ?   ? English   ? espanol   ? francais   ? Bahasa Indonesia   ? italiano   ? 日本語   ? 韓國語   ? македонски   ? Nederlands   ? portugues   ? русский   ? sicilianu   ? sloven??ina   ? ???   ? Ti?ng Vi?t   ? 中文（??）   ? 中文（繁體）   ? +/?