蓝皮书计划第14号特别报告（Project Blue Book Special Report No. 14，1955年）

> NOTE: This is a **bounded slice** (11 pages) of the 309-page report — the Summary, the Introduction / Origin and Nature of Data, the two headline statistical figures (Figures 3 and 8), and the Conclusions. It is NOT the full document. The narrative pages and the figures were produced by Opus-vision OCR of rendered page images (figures transcribed as structured tables, with each reliability group's counts arithmetically cross-checked against the category totals); the Conclusions pages were reconstructed from the document's embedded text layer with programmatic correction of letter-spacing artifacts. Page markers show the report's printed page number (source PDF page in parentheses). The linked scan is the authoritative full document. <!-- p.vii (PDF p.7) --> SUMMARY Reports of unidentified aerial objects (popularly termed "flying saucers" or "flying discs") have been received by the U. S. Air Force since mid-1947 from many and diverse sources. Although there was no evidence that the unexplained reports of unidentified objects constituted a threat to the security of the U. S., the Air Force determined that all reports of unidentified aerial objects should be investigated and evaluated to determine if "flying saucers" represented technological developments not known to this country. In order to discover any pertinent trends or patterns inherent in the data, and to evaluate or explain any trends or patterns found, appropriate methods of reducing these data from reports of unidentified aerial objects to a form amenable to scientific appraisal were employed. In general, the original data upon which this study was based consisted of impressions and interpretations of apparently unexplainable events, and seldom contained reliable measurements of physical attributes. This subjectivity of the data presented a major limitation to the drawing of significant conclusions, but did not invalidate the application of scientific methods of study. The reports received by the U. S. Air Force on unidentified aerial objects were reduced to IBM punched-card abstracts of the data by means of logically developed forms and standardized analysis procedures. Evaluation of sighting reports, a crucial step in the preparation of the data for statistical treatment, consisted of an appraisal of the reports and the subsequent categorizing of the object or objects described in each report. A detailed description of this phase of the study stresses the careful attempt to maintain complete objectivity and consistency. Analysis of the refined and evaluated data derived from the original reports of sightings comprised (1) a systematic attempt to ferret out any distinguishing characteristics inherent in the data or any of their segments, (2) a concentrated study of any trends or patterns found, and (3) an attempt to determine the probability that any of the UNKNOWNS represent observations of a class, or classes, of "flying saucers". The first step in the analysis of the data revealed the existence of certain apparent similarities between cases of objects definitely identified and those not identified. Statistical methods of testing were applied which indicated a low probability that these apparent similarities were significant. An attempt to determine the probability that any of the UNKNOWNS represent observations of a class, or classes, of "flying saucers" necessitated a thorough re-examination and re-evaluation of cases of objects not originally identified; this led to the conclusion that the probability was very small, <!-- p.viii (PDF p.8) --> Therefore, on the basis of this evaluation of the information, it is considered to be highly improbable that reports of unidentified aerial objects examined in this study represent observations of technological developments outside of the range of present-day scientific knowledge. It is emphasized that there was a complete lack of any valid evidence consisting of physical matter in any case of a reported unidentified aerial object. <!-- p.1 (PDF p.9) --> INTRODUCTION In June, 1947, Kenneth Arnold, a Boise, Idaho, businessman and private pilot, publicly reported the now-famous sighting of a chainlike formation of disc-shaped objects near Mount Rainier, Washington. Resulting newspaper publicity of this incident caught the public interest, and, shortly thereafter, a rash of reports of unidentified aerial objects spawned the term "flying saucers". During the years since 1947, many reports of unidentified aerial objects have been received by the Air Force from many and diverse sources. The unfortunate term "flying saucer", or "flying disc", because of its widespread and indiscriminate use, requires definition. Many definitions have been offered, one of the best being that originated by Dr. J. Allen Hynek, of the Emerson McMillin Observatory of The Ohio State University, who has taken a scientific interest in the problem of unidentified aerial objects since 1949. Dr. Hynek's definition of the term is "any aerial phenomenon or sighting that remains unexplained to the viewer at least long enough for him to write a report about it"(1). Dr. Hynek, elaborating on his definition, says, "Each flying saucer, so defined, has associated with it a probable lifetime. It wanders in the field of public inspection like an electron in a field of ions, until 'captured' by an explanation which puts an end to its existence as a 'flying saucer'"(1). This definition would be applicable to any and all of the sightings which remained unidentified throughout this study. However, the term "flying saucers" shall be used hereafter in this report to mean a novel, airborne phenomenon, a manifestation that is not a part of or readily explainable by the fund of scientific knowledge known to be possessed by the Free World. This would include such items as natural phenomena that are not yet completely understood, psychological phenomena, or intruder aircraft of a type that may be possessed by some source in large enough numbers so that more than one independent mission may have been flown and reported. Thus, these phenomena are of the type which should have been observed and reported more than once. Since 1947, public interest in the subject of unidentified aerial objects fluctuated more or less within reasonable limits until the summer of 1952, when the frequency of reports of sightings reached a peak, possibly stimulated by several articles on the subject in leading popular magazines. Early in 1952, the Air Force's cumulative study and analysis of reported sightings indicated that the majority of reports could be accounted for as misinterpretations of known objects (such as meteors, balloons, or aircraft), a few as the result of mild hysteria, and a very few as the result of unfamiliar meteorological phenomena and light aberrations. However, (1) Hynek, J. A., "Unusual Aerial Phenomena", Journal of the Optical Society of America, 43 (4), pp 311-314, April, 1953. <!-- p.2 (PDF p.10) --> a significant number of fairly complete reports by reliable observers remained unexplained. Although no evidence existed that unexplained reports of sightings constituted a physical threat to the security of the U. S., in March, 1952, the Air Force decided that all reports of unidentified aerial objects should be investigated and evaluated to determine if "flying saucers" represented technological developments not known to this country. Originally, the problem involved the preparation and analysis of about 1,300 reports accumulated by the Air Force between 1947 and the end of March, 1952. During the course of the work, the number of reports submitted for analysis and evaluation more than tripled, the result of the unprecedented increase in observations during 1952. Accordingly, this study is based on a number of reports considered to be large enough for a preliminary statistical analysis, approximately 4,000 reports. This study was undertaken primarily to categorize the available reports of sightings and to determine the probability that any of the reports of unidentified aerial objects represented observations of "flying saucers". With full cognizance of the quality of the data available for study, yet with an awareness of the proportions this subject has assumed at times in the public mind, this work was undertaken with all the seriousness accorded to a straightforward scientific investigation. In order to establish the probability that any of the reports of unidentified aerial objects represented observations of "flying saucers", it was necessary to make an attempt to answer the question "What is a 'flying saucer'?". However, it must be emphasized that this was only incidental to the primary purpose of the study, the determination of the probability that any of the reports of unidentified aerial objects represented observations of "flying saucers", as defined on Page 1. The basic technique for this study consisted of reducing the available data to a form suitable for mechanical manipulation, a prerequisite for the application of preliminary statistical methods. The use of International Business Machine Corporation's systems was chosen as the best available mechanical equipment. The reduction of data contained in sighting reports into a form suitable for transfer to IBM punched cards was extremely difficult and time consuming. For this study a panel of consultants was formed, consisting of both experts within and outside ATIC. During the course of the work, guidance and advice were received from the panel. The professional experience available from the panel covered major scientific fields and numerous specialized fields. All records and working papers of this study have been carefully preserved in an orderly fashion suitable for ready reference. These <!-- p.3 (PDF p.11) --> records include condensations of all individual sighting reports, and the IBM cards used in various phases of the study. ORIGIN AND NATURE OF DATA Reports of sightings were received by the U. S. Air Force from a representative cross section of the population of the U. S., and varied widely in completeness and quality. Included were reports from reputable scientists, housewives, farmers, students, and technically trained members of the Armed Forces. Reports varied in length from a few sentences stating that a "flying saucer" had been sighted, to those containing thousands of words, including description, speculation, and advice on how to handle the "problem of the 'flying saucers'". Some reports were of high quality, conservative, and as complete as the observer could make them; a few originated from people confined to mental institutions. A critical examination of the reports revealed, however, that a high percentage of them was submitted by serious people, mystified by what they had seen and motivated by patriotic responsibility. Three principal sources of reports were noted in the preliminary review of the data. The bulk of the data arrived at ATIC through regular military channels, from June, 1947, until the middle of 1952. A second type of data consisted of letters reporting sightings sent by civilian observers directly to ATIC. Most of these direct communications were dated subsequent to April 30, 1952, and are believed to be the result of a suggestion by a popular magazine that future reports be directed to the Air Technical Intelligence Center. As could be expected, a large number of letters was received following this publicity. A third type of data was that contained in questionnaire forms completed by the observer himself. A questionnaire form, developed during the course of this study, was mailed by ATIC to a selected group of writers of direct letters with the request that the form be completed and returned. Approximately 1,000 responses were received by ATIC. In general, the data were subjective, consisting of qualified estimates of physical characteristics rather than of precise measurements. Furthermore, most of the reports were not reduced to written form immediately. The time between sighting and report varied from one day to several years. Both of these factors introduced an element of doubt concerning the validity of the original data, and increased its subjectivity. This was intensified by the recognized inability of the average individual to estimate speeds, distances, and sizes of objects in the air with any degree of accuracy. In spite of these limitations, methods of statistical analysis of such reports in sufficiently large groups are valid. The danger lies in the possibility of <!-- p.4 (PDF p.12) --> forgetting the subjectivity of the data at the time that conclusions are drawn from the analysis. It must be emphasized, again and again, that any conclusions contained in this report are based NOT on facts, but on what many observers thought and estimated the true facts to be. Altogether, the data for this study consisted of approximately 4,000 reports of sightings of unidentified aerial objects. The majority were received through military channels or in the form of observer-completed questionnaires; a few were accepted in the form of direct letters from unquestionably reliable sources. Sightings made between June, 1947, and December, 1952, were considered for this study. Sightings alleged to have occurred prior to 1947 were not considered, since they were not reported to official sources until after public interest in "flying saucers" had been stimulated by the popular press. REDUCTION OF DATA TO MECHANIZED COMPUTATION FORM As received by the Air Technical Intelligence Center, the sighting reports were not in a form suitable for even a quasi-scientific study. A preliminary review of the data indicated the need for standardized interrogation procedures and supplemental forms for the reduction of currently held and subsequently acquired data to a form amenable to scientific appraisal. The plan for reduction of the data to usable form consisted of a program of development comprising four major steps: (1) a systematic listing of the factors necessary to evaluate the observer and his report, and to identify the unknown object observed; (2) a standard scheme for the transfer of data to a mechanized computation system; (3) an orderly means of relating the original data to all subsequent forms; and (4) a consistent procedure for the identification of the phenomenon described by the original data. Questionnaire The first reports received by ATIC varied widely in completeness and quality. Air Force Letter 200-5(2) and Air Force Form 112(1) were attempts to fix responsibility for and improve the quality of the reports of sightings. To coordinate past efforts and to provide standardization for (1) A modified Air Force Form 112 lists pertinent questions to be answered in regard to an unidentified-object sighting. (2) Air Force Letter 200-5 places responsibility with the Air Force for the investigation, reporting, and analysis of unidentified aerial objects. This letter is dated 29 April 1952. <!-- p.16 (PDF p.24) --> Graphical Presentation Graphical representation of the important information contained in the tables is presented in Figures 1 through 38. These figures present the distributions of the important variables only by the total number of cases in each identification category, since no significant differences were found between the distributions of "Certain" and "Doubtful" identifications of objects with respect to the variables. A chronological study of these figures will afford a broad picture of the tabulated information, without the necessity of a detailed study of the tables. A critical examination of the figures will show that no trends, patterns, or correlations are to be found, with the exception of Figures 18 through 30. The apparent similarity of the distributions shown by these mirror graphs, Figures 18 through 23, was tested by statistical methods which showed that there was a low probability that the distributions of the KNOWNS and UNKNOWNS by these characteristics were the same. These tests and their interpretation are discussed in the following section. For purposes of this study, the strategic areas, shown in Figures 32 through 38, and Tables A213 through A240, Appendix A, were designated on the basis of concentration of reports of OBJECT SIGHTINGS in an area. No other interpretation of the tables or remaining charts was deemed necessary. Advanced Study of the Data It was recognized that the lack of any patterns or trends, as shown by the tabulations and graphs, provided an inaccurate basis for drawing definite conclusions. Accordingly, shortly before the sorting and tabulation program was concluded, a program of study of the data was developed to utilize statistical and other mathematical methods, which could lead to a more concrete interpretation of the problem. Position of the Sun Relative to the Observer The first thing that was done was to calculate the angle of elevation of the sun above the horizon and its bearing from true north as seen by the observer at the time of each sighting. With this information, it could then be determined whether there was a possibility that the reported object could have been illuminated by light from the sun. In addition, it could be determined whether an object could be a mock sun (sun dog) or whether there was a possibility of specular reflection from an aircraft at the position of the object, which would give the appearance of a "flying disc". A program of computation was set up and carried out to obtain the angle of elevation and the bearing of the sun for each sighting. All information needed for this calculation was available on the deck of IBM cards. <!-- p.19 (PDF p.27) --> FIGURE 3 — DISTRIBUTION OF OBJECT SIGHTINGS BY EVALUATION FOR ALL YEARS (structured transcription of the pie chart; total = 2199 sightings) | Evaluation | Count | Percent | |---|---|---| | Astronomical | 479 | 21.8% | | Aircraft | 474 | 21.5% | | Unknown | 434 | 19.7% | | Balloon | 339 | 15.4% | | Insufficient info. | 240 | 10.9% | | Other | 233 | 10.3% | <!-- p.24 (PDF p.32) --> FIGURE 8 — DISTRIBUTION OF OBJECT SIGHTINGS BY SIGHTING RELIABILITY GROUP, WITH EVALUATION DISTRIBUTION FOR EACH GROUP (structured transcription of the pie charts; total = 2199 = 100%) Reliability-group totals: Excellent 213 (9.7%); Good 757 (34.5%); Doubtful 794 (36.0%); Poor 435 (19.8%). Evaluation distribution within each reliability group (count = percent): | Evaluation | Excellent (213) | Good (757) | Doubtful (794) | Poor (435) | |---|---|---|---|---| | Unknown | 71 = 33.3% | 188 = 24.8% | 103 = 13.0% | 72 = 16.6% | | Astronomical | 52 = 24.4% | 174 = 23.0% | 154 = 19.4% | 99 = 22.8% | | Aircraft | 41 = 19.2% | 166 = 22.0% | 198 = 24.9% | 69 = 15.9% | | Balloon | 25 = 11.8% | 127 = 16.8% | 131 = 16.5% | 56 = 12.9% | | Insufficient info. | 9 = 4.2% | 27 = 3.6% | 111 = 14.0% | 93 = 21.4% | | Other | 15 = 7.0% | 75 = 9.9% | 97 = 12.2% | 46 = 10.6% | <!-- p.93 (PDF p.101) --> (12) Case XII. The object had windows in its top and front and its top midsection. It also had a set of propellers around its waist. It is not possible, therefore, to derive a verified model of a "flying saucer" from the data that have been gathered to date. This point is important enough to emphasize. Out of about 4, 000 people who said they saw a "flying saucer", sufficiently detailed descriptions were given in only 12 cases. Having culled the cream of the crop, it is still impossible to develop a picture of what a "flying saucer" is. In addition to this study of the good UNKNOWNS, an attempt was made to find groups of UNKNOWNS for which the observed characteristics were the same. No such groups were found. On the basis of this evidence, therefore, there is a low probability that any of the UNKNOWNS represent observations of a class of "flying saucers". It may be that some reports represent observations of not one but several classes of objects that might have been "flying saucers"; however, the lack of evidence to confirm even one class would seem to make this possibility remote. It is pointed out that some of the cases of KNOWNS, before identification, appeared fully as bizarre as any of the 12 cases of good UNKNOWNS, and, in fact, would have been placed in the class of good UNKNOWNS had it not been possible to establish their identity. This is, of course, contrary to the bulk of the publicity that has been given to this problem. The reason for the nature of this publicity was clearly brought out during the re-evaluation study. It is a definite fact that upon reading a few reports, the reader becomes convinced that "flying saucers" are real and are some form of sinister contrivance. This reaction is independent of the training of the reader or of his attitude toward the problem prior to the initial contact. It is unfortunate that practically all of the articles, books, and news stories dealing with the phenomenon of the "flying saucer" were written by men who were in this category, that is, men who had read only a few selected reports. This is accentuated by the fact that, as a rule, only the more lurid-sounding reports are cited in these publications. Were it not for this common psychological tendency to be captivated by the mysterious, it is possible that no problem of this nature would exist. The reaction, mentioned above, that after reading a few reports, the reader is convinced that "flying saucers" are real and are some form of sinister contrivance, is very misleading. As more and more of the reports are read, the feeling that "saucers" are real fades, and is replaced by a feeling of skepticism regarding their existence. The reader eventually reaches a point of saturation, after which the reports contain no new information at all and are no longer of any interest. This feeling of surfeit was universal among the personnel who worked on this project, and continually necessitated a conscious effort on their part to remain objective. 93 <!-- p.94 (PDF p.102) --> CONCLUSIONS It can never be absolutely proven that "flying saucers" do not exist. This would be true if the data obtained were to include complete scientific measurements of the attributes of each sighting, as well as complete and detailed descriptions of the objects sighted. It might be possible to demonstrate the existence of "flying saucers" with data of this type, IF they were to exist. Although the reports considered in this study usually did not contain scientific measurements of the attributes of each sighting, it was possible to establish certain valid conclusions by the application of statistical methods in the treatment of the data. Scientifically evaluated and arranged, the data as a whole did not show any marked patterns or trends. The inaccuracies inherent in this type of data, in addition to the incompleteness of a large proportion of the reports, may have obscured any patterns or trends that otherwise would have been evident. This absence of indicative relationships necessitated an exhaustive study of selected facets of the data in order to draw any valid conclusions. A critical examination of the distributions of the important characteristics of sightings, plus an intensive study of the sightings evaluated as UNKNOWN, led to the conclusion that a combination of factors, principally the reported maneuvers of the objects and the unavailability of supplemental data such as aircraft flight plans or balloon-launching records, resulted in the failure to identify as KNOWNS most of the reports of objects classified as UNKNOWNS. An intensive study, aimed at finding a verified example of a "flying saucer" or at deriving a verified model or models of "flying saucers" (as defined on Page 1), led to the conclusion that neither goal could be attained using the present data. It is emphasized that there was a complete lack of any valid evidence consisting of physical matter in any case of a reported unidentified aerial object. Thus, the probability that any of the UNKNOWNS considered in this study are "flying saucers" is concluded to be extremely small, since the most complete and reliable reports from the present data, when isolated and studied, conclusively failed to reveal even a rough model, and since the data as a whole failed to reveal any marked patterns or trends. Therefore, on the basis of this evaluation of the information, it is considered to be highly improbable that any of the reports of unidentified aerial objects examined in this study represent observations of technological developments outside the range of present-day scientific knowledge. 94

> 注：这是这份309页报告的一个**有界切片**（11页）——摘要、引言／数据的来源与性质、两幅主要的统计图（图3和图8），以及结论。它并非完整文件。叙述性页面与图表由 Opus 视觉 OCR 对渲染后的页面图像进行处理而成（图表被转写为结构化表格，每个可靠性分组的计数都与各类别总计进行了算术交叉核对）；结论部分各页由文件内嵌的文本层重建而来，并对字母间距伪影进行了程序化校正。页面标记显示报告印刷的页码（源 PDF 页码在括号内）。所链接的扫描件为权威的完整文件。 <!-- p.vii (PDF p.7) --> 摘要 自1947年年中以来，美国空军（U. S. Air Force）从众多不同来源收到了关于不明空中物体（俗称"飞碟"或"飞盘"）的报告。尽管没有证据表明这些无法解释的不明物体报告构成了对美国安全的威胁，空军仍判定，应对所有不明空中物体的报告进行调查与评估，以确定"飞碟"是否代表本国所不了解的技术发展。 为发现数据中固有的任何相关趋势或模式，并对所发现的任何趋势或模式进行评估或解释，采用了适当的方法，将这些来自不明空中物体报告的数据归约为适于科学评价的形式。总体而言，本研究所依据的原始数据由对表面上无法解释之事件的印象与解读构成，且很少包含对物理属性的可靠测量。数据的这种主观性对得出有意义的结论构成了一项主要限制，但并未使科学研究方法的应用失效。 通过逻辑化设计的表格和标准化的分析程序，美国空军收到的关于不明空中物体的报告被归约为数据的 IBM 穿孔卡片摘要。对目击报告的评估是为统计处理准备数据的关键一步，包括对报告的评价以及随后对每份报告所描述的一个或多个物体的归类。对本研究这一阶段的详细描述，强调了为保持完全的客观性与一致性所做的审慎努力。 对从原始目击报告中得出的、经过精炼与评估的数据所作的分析包括：（1）系统地尝试搜寻数据或其任何片段中固有的任何区别性特征；（2）对所发现的任何趋势或模式进行集中研究；以及（3）尝试确定任何"不明"项（UNKNOWNS）代表对某一类或某几类"飞碟"之观察的概率。 数据分析的第一步揭示，在被确定无疑地识别出的物体案例与未被识别的物体案例之间，存在某些表面上的相似性。所应用的统计检验方法表明，这些表面相似性具有显著性的概率很低。为确定任何"不明"项（UNKNOWNS）代表对某一类或某几类"飞碟"之观察的概率，有必要对那些原本未被识别的物体案例进行彻底的重新审查与重新评估；这导致得出结论：该概率非常小， <!-- p.viii (PDF p.8) --> 因此，基于对这些信息的评估，本研究中所审查的不明空中物体报告，代表对超出当今科学知识范围之技术发展之观察的可能性，被认为是极不可能的。需强调的是，在任何一例所报告的不明空中物体案例中，都完全缺乏由物质构成的任何有效证据。 <!-- p.1 (PDF p.9) --> 引言 1947年6月，爱达荷州博伊西（Boise, Idaho）的商人兼私人飞行员肯尼斯·阿诺德（Kenneth Arnold）公开报告了如今著名的那次目击事件——在华盛顿州雷尼尔山（Mount Rainier, Washington）附近，呈链状编队的碟形物体。此事件随后引发的报纸报道引起了公众兴趣，不久之后，大量关于不明空中物体的报告催生了"飞碟"一词。自1947年以来的这些年里，空军从众多不同来源收到了许多关于不明空中物体的报告。 "飞碟"或"飞盘"这一不恰当的用语，由于其广泛而不加区分的使用，需要加以定义。已有许多定义被提出，其中最佳者之一由俄亥俄州立大学（The Ohio State University）埃默森·麦克米林天文台（Emerson McMillin Observatory）的 J. 艾伦·海尼克博士（Dr. J. Allen Hynek）提出，他自1949年起就对不明空中物体问题抱有科学的兴趣。海尼克博士对该词的定义是："任何对观察者而言至少在一段足以让他写出一份报告的时间内仍无法解释的空中现象或目击"(1)。海尼克博士在阐述其定义时说："如此定义的每一个飞碟，都伴随着一个可能的存续期。它在公众审视的场域中游走，犹如离子场中的一个电子，直到被某种解释'捕获'，从而结束它作为'飞碟'的存在"(1)。 这一定义适用于本研究中始终未被识别的任何及所有目击。然而，"飞碟"一词在本报告下文中将用于指一种新奇的空中现象，一种并非自由世界（Free World）已知所掌握的科学知识储备的组成部分、亦不易由该知识储备解释的表现。这将包括诸如尚未被完全理解的自然现象、心理现象，或某种入侵飞行器——其类型可能被某一来源大量拥有，多到足以执行并报告不止一次独立的任务。因此，这些现象属于本应被观察并报告不止一次的类型。 自1947年以来，公众对不明空中物体这一主题的兴趣或多或少地在合理范围内起伏，直到1952年夏天，此时目击报告的频率达到了顶峰，这可能是受到几家主流大众杂志上关于该主题的若干文章的刺激。 1952年初，空军对所报告目击的累积研究与分析表明，大多数报告可被解释为对已知物体（如流星、气球或飞行器）的误判，少数是轻度歇斯底里的结果，极少数是不熟悉的气象现象与光学畸变的结果。然而， (1) Hynek, J. A., "Unusual Aerial Phenomena", Journal of the Optical Society of America, 43 (4), 第311–314页, 1953年4月。 <!-- p.2 (PDF p.10) --> 由可靠观察者所作的相当数量的相当完整的报告仍未得到解释。尽管没有证据表明这些无法解释的目击报告构成了对美国安全的物理威胁，1952年3月，空军决定应对所有不明空中物体的报告进行调查与评估，以确定"飞碟"是否代表本国所不了解的技术发展。 最初，该问题涉及对空军在1947年至1952年3月底之间累积的约1,300份报告的准备与分析。在工作过程中，提交以供分析和评估的报告数量增加了两倍多，这是1952年间观察数量空前增加的结果。因此，本研究所依据的报告数量被认为足以进行初步统计分析，约为4,000份报告。 开展本研究的主要目的是对现有的目击报告进行归类，并确定任何不明空中物体报告代表对"飞碟"之观察的概率。在充分认识到可供研究之数据质量的同时，又意识到这一主题有时在公众心目中所达到的规模，本工作以对待一项直截了当的科学调查所应有的全部严肃性加以开展。为确立任何不明空中物体报告代表对"飞碟"之观察的概率，有必要尝试回答"什么是'飞碟'？"这一问题。然而，必须强调的是，这仅仅是本研究主要目的的附带事项；其主要目的是确定任何不明空中物体报告代表对第1页所定义之"飞碟"之观察的概率。 本研究的基本技术是将可用数据归约为适于机械操作的形式，这是应用初步统计方法的先决条件。选用国际商业机器公司（International Business Machine Corporation）的系统，作为最佳的可用机械设备。 将目击报告中所含数据归约为适于转移到 IBM 穿孔卡片的形式，极其困难且耗费时间。 为本研究组建了一个顾问小组，由 ATIC 内部与外部的专家共同组成。在工作过程中，得到了该小组的指导与建议。该小组所能提供的专业经验涵盖了主要的科学领域和众多专门领域。 本研究的所有记录与工作文件都已以适于随时查阅的有序方式被妥善保存。这些 <!-- p.3 (PDF p.11) --> 记录包括所有个别目击报告的浓缩稿，以及在研究各阶段所使用的 IBM 卡片。 数据的来源与性质 美国空军从美国人口的一个有代表性的横断面收到了目击报告，这些报告在完整性与质量上差异极大。其中包括来自有声望的科学家、家庭主妇、农民、学生以及受过技术训练的武装部队成员的报告。报告的长度不一，短的只有几句话陈述目击到了一个"飞碟"，长的则包含数千字，包括描述、推测以及关于如何应对"'飞碟'问题"的建议。有些报告质量上乘、审慎且尽观察者所能做到的那样完整；少数来自被收容于精神病院的人员。然而，对报告的批判性审查揭示，其中很高比例是由严肃认真的人提交的——他们对所见之物感到困惑，并出于爱国责任感而提交报告。 在对数据的初步审阅中，注意到报告有三个主要来源。从1947年6月直到1952年年中，大部分数据通过常规军事渠道抵达 ATIC。 第二类数据由民间观察者直接寄往 ATIC 的报告目击的信件构成。这些直接通信大多注明的日期晚于1952年4月30日，据信是某家大众杂志建议今后的报告应寄往航空技术情报中心（Air Technical Intelligence Center）的结果。正如所预料的那样，在这一宣传之后收到了大量信件。 第三类数据是由观察者本人填写的问卷表格中所含的数据。在本研究过程中开发的一份问卷表格，由 ATIC 邮寄给一组经挑选的直接来信者，请其填写表格并寄回。ATIC 收到了约1,000份回复。 总体而言，这些数据是主观的，由对物理特征的有保留的估计而非精确的测量构成。此外，大多数报告并未在目击后立即写成书面形式。从目击到报告之间的时间从一天到数年不等。这两个因素都给原始数据的有效性带来了一种存疑的成分，并增加了其主观性。这一点又因人们公认的、普通人无法以任何准确程度估计空中物体的速度、距离与大小这一事实而加剧。尽管存在这些限制，对足够大量的此类报告进行统计分析的方法仍然是有效的。危险在于有可能在 <!-- p.4 (PDF p.12) --> 从分析中得出结论时忘记了数据的主观性。必须一再强调的是，本报告中所含的任何结论所依据的并非事实，而是众多观察者对真实事实所作的想法与估计。 总的来说，本研究的数据由约4,000份不明空中物体的目击报告构成。其中大多数是通过军事渠道或以观察者填写的问卷形式收到的；少数以来自无可置疑之可靠来源的直接信件形式被采纳。本研究考虑了1947年6月至1952年12月之间发生的目击。据称发生在1947年之前的目击未予考虑，因为在公众对"飞碟"的兴趣被大众媒体激发之前，这些目击并未向官方来源报告。 数据归约为机械化计算形式 航空技术情报中心收到的目击报告，其形式甚至不适于进行准科学的研究。对数据的初步审阅表明，需要标准化的询问程序和补充表格，以将当前持有的及随后获取的数据归约为适于科学评价的形式。 将数据归约为可用形式的方案，由一项包含四个主要步骤的开发计划构成：（1）系统地列出评估观察者及其报告、以及识别所观察到的不明物体所必需的各项因素；（2）将数据转移到机械化计算系统的标准方案；（3）将原始数据与所有后续表格相关联的有序方法；以及（4）识别原始数据所描述之现象的一致性程序。 问卷 ATIC 收到的最初一批报告在完整性与质量上差异极大。空军第200-5号通函(2)和空军第112号表格(1)是为目击报告确定责任归属并提高其质量的尝试。为协调以往的努力并为 (1) 一份经修改的空军第112号表格，列出了就一次不明物体目击所需回答的相关问题。 (2) 空军第200-5号通函将不明空中物体的调查、报告与分析之责任归于空军。该通函日期为1952年4月29日。 <!-- p.16 (PDF p.24) --> 图示 表格中所含重要信息的图示，呈现于图1至图38中。这些图仅按每个识别类别中的案例总数来呈现各重要变量的分布，因为就这些变量而言，物体识别为"确定"（Certain）与"存疑"（Doubtful）的分布之间未发现显著差异。对这些图按时间顺序的研究将给出所制表信息的总体图景，而无需对表格进行详细研究。 对这些图的批判性审查将表明，除图18至图30外，未发现任何趋势、模式或相关性。这些镜像图（图18至图23）所显示的分布的表面相似性，经统计方法检验，表明"已知"项（KNOWNS）与"不明"项（UNKNOWNS）按这些特征的分布相同的概率很低。这些检验及其解读在下一节中讨论。就本研究而言，图32至图38以及附录A中的表A213至A240所示的战略区域，是根据某一区域内物体目击（OBJECT SIGHTINGS）报告的集中程度来划定的。对表格或其余图表的其他解读被认为没有必要。 数据的深入研究 人们认识到，正如制表与图表所显示的那样，缺乏任何模式或趋势，为得出确定结论提供了一个不准确的基础。因此，在分类与制表计划即将结束之前不久，制定了一项数据研究计划，以运用统计及其他数学方法，从而可能导向对该问题更为具体的解读。 太阳相对于观察者的位置 首先所做的是，计算在每次目击发生时，从观察者的视角所见的太阳在地平线之上的仰角及其相对于正北的方位角。有了这一信息，便可确定所报告的物体是否有可能被来自太阳的光所照亮。此外，还可确定某个物体是否可能是幻日（即假日，sun dog），或者在物体所在位置是否有可能存在来自飞行器的镜面反射——这会呈现出"飞盘"的外观。 设立并执行了一项计算程序，以求得每次目击时太阳的仰角与方位角。此项计算所需的全部信息都在那叠 IBM 卡片上可用。 <!-- p.19 (PDF p.27) --> 图3 — 按评估分类的物体目击分布（所有年份） （饼图的结构化转写；总计 = 2199 次目击） | 评估类别 | 计数 | 百分比 | |---|---|---| | 天文现象（Astronomical） | 479 | 21.8% | | 飞行器（Aircraft） | 474 | 21.5% | | 不明（Unknown） | 434 | 19.7% | | 气球（Balloon） | 339 | 15.4% | | 信息不足（Insufficient info.） | 240 | 10.9% | | 其他（Other） | 233 | 10.3% | <!-- p.24 (PDF p.32) --> 图8 — 按目击可靠性分组的物体目击分布，并附各分组的评估分布 （饼图的结构化转写；总计 = 2199 = 100%） 各可靠性分组的总计：优（Excellent）213（9.7%）；良（Good）757（34.5%）；存疑（Doubtful）794（36.0%）；差（Poor）435（19.8%）。 各可靠性分组内的评估分布（计数 = 百分比）： | 评估类别 | 优（213） | 良（757） | 存疑（794） | 差（435） | |---|---|---|---|---| | 不明（Unknown） | 71 = 33.3% | 188 = 24.8% | 103 = 13.0% | 72 = 16.6% | | 天文现象（Astronomical） | 52 = 24.4% | 174 = 23.0% | 154 = 19.4% | 99 = 22.8% | | 飞行器（Aircraft） | 41 = 19.2% | 166 = 22.0% | 198 = 24.9% | 69 = 15.9% | | 气球（Balloon） | 25 = 11.8% | 127 = 16.8% | 131 = 16.5% | 56 = 12.9% | | 信息不足（Insufficient info.） | 9 = 4.2% | 27 = 3.6% | 111 = 14.0% | 93 = 21.4% | | 其他（Other） | 15 = 7.0% | 75 = 9.9% | 97 = 12.2% | 46 = 10.6% | <!-- p.93 (PDF p.101) --> (12) 案例XII。该物体的顶部、前部及顶部中段都有窗户。它的腰部一圈还装有一组螺旋桨。 因此，无法从迄今所收集的数据中导出一个经过验证的"飞碟"模型。这一点重要到值得强调。在约4,000名声称自己看到了"飞碟"的人中，仅有12个案例给出了足够详尽的描述。在已经精选出其中最优者之后，仍然不可能勾勒出"飞碟"究竟是什么的图景。 除了对这些优质"不明"项（UNKNOWNS）的研究之外，还尝试找出若干所观察到之特征相同的"不明"项分组。未发现任何此类分组。 因此，基于这一证据，任何"不明"项（UNKNOWNS）代表对某一类"飞碟"之观察的概率很低。有可能某些报告代表的是对并非一类、而是若干类可能曾是"飞碟"之物体的观察；然而，缺乏证据来确证哪怕一类，这似乎使得这种可能性变得渺茫。需指出的是，某些"已知"项（KNOWNS）的案例，在被识别之前，看上去与那12个优质"不明"项（UNKNOWNS）案例中的任何一个一样离奇；事实上，若非能够确定其身份，它们本会被归入优质"不明"项之列。 当然，这与已就此问题所作的大量宣传背道而驰。这种宣传之性质的成因，在重新评估研究的过程中被清楚地揭示了出来。一个确凿的事实是：在阅读了少数几份报告之后，读者便会确信"飞碟"是真实的，且是某种险恶的装置。这种反应与读者所受的训练无关，也与其在初次接触之前对该问题的态度无关。不幸的是，几乎所有论及"飞碟"现象的文章、书籍和新闻报道，都是由属于这一类别的人——即只读过少数几份经挑选之报告的人——所写。这一点又因如下事实而被强化：通常而言，这些出版物中只引用那些听起来较为骇人耸动的报告。倘若不是这种被神秘事物所吸引的普遍心理倾向，那么很可能根本不会存在这类问题。 上文提到的那种反应——即在阅读了少数几份报告之后，读者便确信"飞碟"是真实的，且是某种险恶的装置——是极具误导性的。随着越来越多的报告被阅读，"飞碟"真实存在的感觉逐渐消退，并被对其存在持怀疑的感觉所取代。读者最终会达到一个饱和点，此后报告中根本不再包含任何新信息，也不再有任何意义。这种厌腻之感在参与本项目工作的人员中是普遍存在的，并持续地迫使他们必须有意识地努力保持客观。 93 <!-- p.94 (PDF p.102) --> 结论 永远无法绝对证明"飞碟"不存在。倘若所获得的数据将包含对每次目击之属性的完整科学测量，以及对所目击物体的完整而详尽的描述，那么这一点便会成立。如果"飞碟"果真存在，那么用这种类型的数据或许有可能证明"飞碟"的存在。 尽管本研究中所考虑的报告通常并不包含对每次目击之属性的科学测量，但通过在处理数据时运用统计方法，仍有可能确立某些有效的结论。经过科学的评估与整理，数据整体上并未显示出任何显著的模式或趋势。这类数据中固有的不准确性，加之很大比例报告的不完整性，可能掩盖了本来会显而易见的任何模式或趋势。这种指示性关联的缺失，使得有必要对数据的若干选定方面进行详尽的研究，方能得出任何有效的结论。 对目击之重要特征分布的批判性审查，加上对被评估为"不明"（UNKNOWN）之目击的深入研究，导致得出如下结论：多种因素的组合——主要是所报告的物体的机动动作，以及诸如飞行器飞行计划或气球放飞记录等补充数据的不可得——导致了大多数被归类为"不明"项（UNKNOWNS）的物体报告未能被识别为"已知"项（KNOWNS）。 一项旨在找出"飞碟"经验证之实例、或导出"飞碟"（如第1页所定义）经验证之一个或多个模型的深入研究，导致得出如下结论：使用当前数据，这两个目标均无法实现。 需强调的是，在任何一例所报告的不明空中物体案例中，都完全缺乏由物质构成的任何有效证据。 因此，本研究中所考虑的任何"不明"项（UNKNOWNS）是"飞碟"的概率，被断定为极其微小，因为来自当前数据的最为完整、最为可靠的报告，在被分离出来加以研究时，确凿地未能揭示出哪怕一个粗略的模型，且因为数据整体上未能揭示出任何显著的模式或趋势。 因此，基于对这些信息的评估，本研究中所审查的任何不明空中物体报告，代表对超出当今科学知识范围之技术发展之观察的可能性，被认为是极不可能的。 94