算命之谜

时下外出旅游,不论是到名山古刹还是大小公园,常常会碰到算命、看手相、看面相、抽贴的算命先生。他们或是盲人,或是打扮一副仙风道骨的普通人,他们有的身边像模像样地放着一本《周易》或有关算命之类的书,或摆放着一个笔筒之类的器皿,里面放着做好的竹签,竹签上几句话,或在眼前放着几枚铜钱,专等游客上钩。十月六日,我与妻到一风景区旅游,正在一景点前休息,妻目睹一算命人正给一个大款模样的人算命,妻出于好奇,就挤进去听。架不住诱说,妻说那就给儿子抽一卦吧,给儿子算一算婚姻、事业、前途,然后报过年龄生日时辰。算命人翻翻书,闭目自言自…     

佛光之谜

佛家认为,只有与佛有缘的人,才能看到佛光,因为佛光是从佛的眉宇间放射出的救世之光,吉祥之光。传说1600多年前,敦煌莫高窟建窟前曾闪现“金光”和“千佛”的奇异景象。那么,“金光”和“千佛”的出现,是“佛祖显灵”呢,还是一种自然现象?公元366年的一天傍晚,在中国西北部的甘肃省敦煌市附近的一座沙山上,“佛光”的一次偶尔出现被一个叫乐尊的和尚无意中看到了。看到“佛光”的乐尊当即跪下,并朗声发愿要把他见到“佛光”的地方变成一个令人崇敬的圣洁宝地。受这一理念的感召,经过工匠们千余年断断续续的构筑,终于成就了我们今天看到的这…     

大枫树下有鬼之谜

刘家村村后有棵大枫树,相传这棵树以前吊死过人。现在随着树龄增长,根繁加果实芽发,大枫树周围有了众多小树,成为阴森森的树丛堆。也不知是何年何人先说起,说这阴森森树丛正好给吊死的人安家。从此刘家村人很少单身夜走大枫树下,要么     

The solitaire illusion: An illusion of numerosity

A new illusion in which the apparent number of elements of two kinds is determined by their spatial arrangement is described. The illusion is such that one large cluster appears to contain more elements than several small clusters, clustering being determined by Gestalt principles. The illusion was found both in adults and in children of 8 years.     

The basis of the Bourdon illusion

Day (1990) and Day, Mitchell, and Stecher (1990) recently reported new data on the Bourdon illusion, showing that the effect occurs in novel variations of the classic figure--for example, with orthogonal and parallel test edges--and also that it occurs in the haptic modality. Day (1990) criticized theories of the Bourdon effect proposed by Wenderoth, Criss, and van der Zwan (1990), Wenderoth and O'Connor (1987a, 1987b), and Wenderoth, O'Connor, and Johnson (1986), and proposed his own "perceptual compromise" hypothesis. It is argued that Day has inaccurately portrayed the Wenderoth et al. theory, and that his own hypothesis lacks predictive power because it lacks any reference to neural mechanisms. Day's theory is thus unable to account for extant data, including his own. It is demonstrated how Day's novel experiments provide insights into the mechanisms of the Bourdon effect, and also how the Wenderoth et al. theory can account for the new data of Day (1990) and Day et al. (1990).     

The P&p illusion

Identical letters can appear to differ in size and shape depending on whether they are interpreted as uppercase or lowercase. The effect is most-dramatic with the letter p. Examination of subjects' estimates of the magnitude of the effect for different stimuli suggests that two factors are involved in the illusion. One factor depends only on whether a letter is interpreted as uppercase or lowercase. This factor can be manipulated by changes in the size or case of the surrounding letters. The second factor, which depends on the possibility of interpreting a vertical line alternatively as an ascender or a descender (as in p or y), seems to involve a change in the perceived size of the letters' loops.     

The boogie-woogie illusion

A grid of vertical and horizontal lines, each composed of light and dark squares, is moved rigidly at 45 degrees to the vertical on a gray surround. When the luminance of the background is set midway between the luminances of the light and dark squares, the squares appear to race along the lines even though they are actually 'painted' on the lines. The effect arises from the unequal apparent speeds of the lines and their textures. The light and dark squares along the lines define a first-order pattern whose apparent speed, parallel or along the line, is close to veridical. The lines themselves have no overall luminance difference from the background so that they are defined by a second-order difference. As reported elsewhere, apparent speed is reduced for second-order motion so that the motion perpendicular to the line is perceived as slower than the motion along the line even though they are physically equal. The imbalance creates the impression that the small squares are moving along the lines rather than moving rigidly with them.     

The corridor illusion

Contrary to general belief, the classical corridor illusion is not due solely to the perspective and contextual cues provided by the corridor. Additional factors that are equally important are the inherent spatial anisotropies of the visual system and fixation tendencies.     

The Rawdon-Smith illusion

A loudness illusion is described which was originally reported by Rawdon-Smith and Grindley (1935). It is analogous to the Craik-O’Brien-Cornsweet brightness illusion. Procedures are described for generating and measuring the size of the effect, and data are presented showing factors that influence its magnitude. Other examples are discussed that suggest that this effect is a very general phenomenon.