144' The existing knowledge of the effects of the use of nucr-ear weapons is farfrom. complete. Although numerous tests have been carried out, formi.ng a basisfor the uncierstanding of the physical explosion phenomena, there &re onfy tffoinstances when ttlese veapons have been used in ,lr, on g arg""i -rql*i "g"io"t Iliroshina and on 9 August r-9\5 against Nagas'ki. The outcome of these explosionshas been. painstakingly investigated, in particular with regard. to the nr::mer otpeople ki1led or inJured.J_ and yet considerabl.y different aita are given bydifferent sources, as will be iLlustrated bellw. 145. Furthernore, a.iy assessnent of a hlT)othetical future situation based on theJapanese data *ould have to rest on interpretation and sometimes ertrapofation,as todayrs arsenals contain weapons that are a thoussrd tines nore pov-erful than lh: t*. used in Japan, but also smaJ-ler and, in sone cases, specialized weapons(cf' chap. rr). Thus there are 'ncertainties as to the effects of one sinsreexplosion. l'46. rt is a well-established fact that the explosion of a nucr-ear weapon causes d a:nage through several effects: a powerful bllst wave, intense heat r-adiationand nuclear radiation from the firebau- and from racrioactive farlout. There isalso a pul-se of electronag'etic rad.iation not directly harnfuL to living crearures.However, the size of the area affected. by these various phenomena, theii strength - in absolute terns and rerative to each oit u" - and the extent of the damage theycause wil-I depend strongly on the explosive yield but al-so on a nunber of otherfactors specific to each situation. Among tlese are the height above gxound ofAl35 /392 r,nl1'rt sn Annex I',afle > 4 the explosion, veather conditions and (parti cularly for explosions close to the grounal vind. velocity and' of course, the nature of target. The design of the weapon vi}1 also influence the outcome. 1\7. Should large mrmbers of nuclear weapons ever come to be used' the total effect vould be much more complex than the sul}: of indivi dual cases. This is in
**Analysis**
The text appears to be discussing the effects of nuclear weapons, specifically the physical explosion phenomena, radiation, and damage caused by such weapons. It also touches on the uncertainties and complexities of assessing the effects of nuclear explosions. The text seems to be more focused on the scientific and technological aspects of nuclear weapons rather than any specific social or economic context.

**Category**
Science and technology