Documents / Report
This is the final report of the Scientific Study of Unidentified Flying Objects, conducted by the University of Colorado under Air Force contract F44620-67-C-0035, with Edward U. Condon as scientific director and Daniel S. Gillmor as editor. It was submitted to the National Academy of Sciences on 15 November 1968 for review. The report includes field studies, photographic and radar analyses, case studies, historical chapters and appendices such as the Robertson Panel report and the Twining letter.
a quarter or as a \~asht\lh, The statement means nothing. StatetP.ents
such as that an object looks to be of the same size as a coin held at
ann's' lenJth do, however, convey some )lwanJ ngful information.
Another limitation of nonnal vision that is often rot appreciated
i.s the color blindness of the dark-adapted eye. The human eye really
has two different mechanisrr,c:; in the retina for the conversion of light
energy into nerve stimulus. Photopic vision is the kind that applies
in the daytime or at moderate levels of artlficial illumination. It
involV('s the cont'~'; of the retina, and is involved in color vision.
Scotopic. Vi3i01, is the kind that comes into play at Jaw levels of illum-
ination, It i~volves the rods of the retina which are unable to dis-
tingui~h colors, hence the saying that in the dark all cats are gray.
The transition from photopic to ~cotopic ".,ision normally takes place
at about the level of illumination that c\Jrresponds to the light of
the full moon high in the sky, Nhcn one goes from a brightly lighteJ
31',:3 into G dark room he is blind at first but gr:l.dually dark adapta-
tion occurs ana a transi tion is made from rhotoric to scotopic visiol ..
The abil i ty to sc,-;. but without color discrimiqation, then returns,
Nyctalopia is the naJl~e of a deficiency of visfon whereby dark adapta-
tim doe5 not oceUI anJ is often connected I·lith a Vitamin A dietary
defi I. iency.
If one stares directly at a bright l.ight which is then turned off,
an afterimage I~ill oe seen; tllat is, th r;) image of the Ii ght, hut less
bright and u.,;ua) ly out ('f focu Ii ncgutlvl'
a.fterimagc I~hich looks darKer than tlw ~urrou,idiJlg field of ViCI",
Afterimages have undoubtedly gi ven rise to ~Ol1H.' UFO reports.
The ;lftcrimagl' is the rc--ult of a tC'l1I'or'.. r-y chanj,(c in till' retinu
and so ":"'mains at Ii fixl'U point on the retina. When ~~!~" thell movc~;
his eyes to look i.n Ii diffl'tCllt uir~ctioll, the afterimage seems to move
re I at i ve to the ...;urrc,unJi lIgs . 1ft t .is hel it'vetI by thu observe'l to hl'
4R
a quarter or as a washt.ub. The statement means nothing. StatcI'P.ents
such as that an object looks to be of the same SIze as a coin he~d at
ann/(l' length do, however, convey some liwsnnlgful information.
Another limitation of normal vision that is often r,ot appreciated
is the colnr bI indness of the dark-adapted eye. The human eye really
has two different mechanisrr,o; in the retina for the conversion of light
energy into nerve stimulus. Photopic vision is the kind that applies
in t11(' daytime or at JJ1oderatt' levels of artlficial illumination. It
involv('s the cont's of the retina, and is involved in color vision.
Scotopic, visiOl~ is the kind that comes into play at low levels of illum-
ination, It i,wolvf's the rods of the retina which arc unable to dis-
tinRui~h ~olorH, hence the ~aying that in the dark all cats are gray.
The tJ'ansition from photopic to ~cotopic '"ision normally takes place
at about the level of i lluminr!tion that C("Jrl'esponds to the light of
tht' full moon high in the sky. When one ~oes from a brightly lightl'J
ar,:J in to d dark room he is b lind at fi rs t but gndually dark adapt a-
tion occurs aml a transl tion is made from rhotoric to scotopi.c visiol"
The abil i ty to SCI';, but Iv i thout lOolor discrimi'lation, then returns.
N)'\,talopia is the nall,e of a deficiency of visi.on I~hereby dark adapta-
tio; doe!'. not OCCUI an ,I is often connected I'li th a Vi t ami n A di etary
defi I. laney.
If one start:'s directly at a bright l,ight wllichis then turned off,
an afterimage \dll be st'(m: tllat is, th,,) image of tilt' light, hut less
bright all'! u"iual1~' out l,f t'ocu-;, conti nues to be ~;e(Jn end grauually
fades nway. f'o~;itiv(' ai'tcrimagl's arC' thO!iI' in \~hjch the .imagl1 looks
bright like tb~' ori f!inal st llllUlu:;, but til is ilia: flVt,rSe tr) a I1cgati v\'
afteri.magc I'hich looks uarkl'r tha11 the ~;urrou<idi.!1g nelt.! of vj(,I~.
Af'tcrimagl's have undoubte ..ily gi v\:n rise t.o SOlHl' UFO reports.
The iiftcrilllllgl' is till' re~\ll t of a tC'n1'0r:.I'Y c\wn).\\1 i.n till' ret i IlU
and so -:"'main~ at II fiXl'd POtu!: on tlo(: retinu. Whe)) :.'"r' tl1L'1l move:;
his eyes to 1(0).; i.ll I~ diff\'rent Uir<!ctioll, the afterimage seems to move
rei<ltive to the ,;urr(,unJillgs. rf It Is helil'vell by the observe'l to he-
411 Report, from the classic collection. The PDF is mirrored here; the original link is under it. 1497 pages are in the text index: search them above, or from the library's search.