Our conception of time depends on the way we measure it

我们对时间的概念取决于我们测量时间的方式

AAccording to archaeological evidence, at least 5,000 years ago, and long before the advent of the Roman Empire, the Babylonians began to measure time, introducing calendars to co-ordinate communal activities, to plan the shipment of goods and, in particular, to regulate planting and harvesting. They based their calendars on three natural cycles: the solar day, marked by the successive periods of light and darkness as the earth rotates on its axis; the lunar month, following the phases of the moon as it orbits the earth; and the solar year, defined by the changing seasons that accompany our planet`s revolution around the sun.

A 有考古证据表明，至少5000年前，早在罗马帝国尚未出现之时，巴比伦人就开始测量时间，他们引进日历来统筹公共活动，计划货物装运，特别是管控作物种植和收割。日历的编排基于三个自然周期：以由地球绕地轴自转形成的连续的光明与黑暗为标记的太阳日；以由月球环绕地球公转形成的月相来衡量的太阴月；以及根据地球绕太阳公转形成的四季来定义的回归年。

BBefore the invention of artificial light, the moon had greater social impact. And, for those living near the equator in particular, its waxing and waning was more conspicuous than the passing of the seasons. Hence, the calendars that were developed at the lower latitudes were influenced more by the lunar cycle than by the solar year. In more northern climes, however, where seasonal agriculture was practised, the solar year became more crucial. As the Roman Empire expanded northward, it organised its activity chart for the most part around the solar year.

B 在人造光发明以前，月亮对社会产生的影响尤为显著。尤其对于赤道附近的居民而言，月圆月缺比季节更替更加明显。因此，低纬度地区日历的形成更多受到月运周期的影响，而不是回归年。然而，在践行季节性农业的更偏北的气候带，回归年则更为重要。随着罗马帝国向北扩张，它的活动图表通常都是根据回归年而编排的。

C 早在罗马帝国建立几个世纪以前，埃及人就已制定了市政日历，规定一年有12个月，每月有30天，此外还有5天用来补充一个近似回归年。每10天以特定星群的出现为标志，这些星群被称作“德坎”(黄道十度分度)。天狼星刚好在日出之前升起，此时可以看见12个德坎横跨天空，而这一现象会在每年极其重要的尼罗河泛洪前后出现。埃及人赋予12个德坎的宇宙意义使他们形成一种新的系统，他们将每一个黑夜区间(之后又将每一个白昼区间)分成12等份。这些时段被称为日光时，因为它的持续时间随着季节更替引起的昼夜长度的变化而变化。夏季日光时长，冬季日光时短；只有在春分和秋分时白昼与黑夜的时长才是一致的。日光时最早被希腊人采用，然后由罗马人采用并传到欧洲，一直使用了2500多年。

CCenturies before the Roman Empire, the Egyptians had formulated a municipal calendar having 12 months of 30 days, with five days added to approximate the solar year. Each period of ten days was marked by the appearance of special groups of stars called decans. At the rise of the star Sirius just before sunrise, which occurred around the all- important annual flooding of the Nile, 12 decans could be seen spanning the heavens. The cosmic significance the Egyptians placed in the 12 decans led them to develop a system in which each interval of darkness (and later, each interval of daylight) was divided into a dozen equal parts. These periods became known as temporal hours because their duration varied according to the changing length of days and nights with the passing of the seasons. Summer hours were long, winter ones short; only at the spring and autumn equinoxes were the hours of daylight and darkness equal. Temporal hours, which were first adopted by the Greeks and then the Romans, who disseminated them through Europe, remained in use for more than 2,500 years.

D 为了在白天记录日光时，发明家们创造了日晷，用太阳阴影的长度和方向来指示时间。水钟与日晷作用相当，用于在夜晚测量日光时。最早的水钟之一是一个水盆，盆底附近有一个小孔，水通过小孔滴出来。随着水降至盆子内表面刻着的小时刻度线以下，水位降低的刻度就表示流逝的时间长度。尽管这些装置在地中海地区十分好用，但在多云并常有严寒天气的欧洲北部却不能一直使用。

E 机械钟的出现意味着尽管人们可以调试它以记录日光时，但机械钟本身更适合于记录长度相同的时间段。由此引发了一个问题，即计时该从何时开始。于是14世纪初，许多新型计时系统逐渐形成。人们计划将一天分为24个等份，而这些计划因为计时起点的不同而不同：意大利时间从日落开始算起，巴比伦时间从日出开始，天文学时间从中午开始，而德国一些大型公共时钟使用的“大钟”时间从午夜开始算起。最终，这些计时方法被“小钟”时间，即法国时间所取代，它将一天分成两个12小时段，从午夜开始算起。

DIn order to track temporal hours during the day, inventors created sundials, which indicate time by the length or direction of the sun`s shadow. The sundial`s counterpart, the water clock, was designed to measure temporal hours at night. One of the first water clocks was a basin with a small hole near the bottom through which the water dripped out. The falling water level denoted the passing hour as it dipped below hour lines inscribed on the inner surface. Although these devices performed satisfactorily around the Mediterranean, they could not always be depended on in the cloudy and often freezing weather of northern Europe.

F 最早有记载的以重量驱动的机械钟1283年建于英国贝德福德郡。这种新型计时器所具有的革命意义既不在于依靠向下的重力提供起动力，也不在于依靠齿轮(至少有1300年的使用历史)传递动力，而在于它使用了一个叫做擒纵机构棘轮装置的部件。15世纪初人们又创造出了螺旋弹簧，也被称为均力圆锥轮。尽管主发条承受着不断变化的张力，但该装置仍能为钟表齿轮提供恒力。到了16世纪，人们发明了摆钟。但由于钟摆摆动弧度很大，因此并不十分有效。

G 为了解决这个问题，原有擒纵机构棘轮装置的改进装置1670年在英格兰发明出来。该装置被称为锚型擒纵机构，以杠杆为基础，形状像一艘船的锚。钟摆的动作对该设备产生振动，以使它抓紧而后释放擒纵机构棘轮装置的每一个齿，从而使得齿轮精确地旋转。与早期摆钟中所使用的原始装置不同，锚型擒纵机构使钟摆的摆动弧度变得很小。此外，这一发明使得摆钟中可以使用长摆，一秒钟摆动一下，从而引发了新型落地柜式造型的开发，也就是落地摆钟。

EThe advent of the mechanical clock meant that although it could be adjusted to maintain temporal hours, it was naturally suited to keeping equal ones. With these, however, arose the question of when to begin counting, and so, in the early 14th century, a number of systems evolved. The schemes that divided the day into 24 equal parts varied according to the start of the count: Italian hours began at sunset, Babylonian hours at sunrise, astronomical hours at midday and `great clock` hours, used for some large public clocks in Germany, at midnight. Eventually these were superseded by`small clock`, or French, hours, which split the day into two 12- hour periods commencing at midnight.

H 如今，高度精确的计时工具为大多数电子设备设置时间。几乎所有的计算机都带有石英钟以控制其运行。此外，从全球定位系统卫星发射的时间信号不仅校准精密导航设备的功能，还被用于移动电话、即时股票交易系统和全国电力分配网。这些以时间为基础的技术已完全成为日常生活的一部分，只有当它们无法正常工作时，我们才会意识到人类多么依赖这些技术。

FThe earliest recorded weight - driven mechanical clock was built in 1283 in Bedfordshire in England. The revolutionary aspect of this new timekeeper was neither the descending weight that provided its motive force nor the gear wheels (which had been around for at least 1,300 years) that transferred the power; it was the part called the escapement. In the early 1400s came the invention of the coiled spring or fusee which maintained constant force to the gear wheels of the timekeeper despite the changing tension of its mainspring. By the 16th century, a pendulum clock had been devised, but the pendulum swung in a large arc and thus was not very efficient.

GTo address this, a variation on the original escapement was invented in 1670, in England. It was called the anchor escapement, which was a lever-based device shaped like a ship's anchor. The motion of a pendulum rocks this device so that it catches and then releases each tooth of the escape wheel, in turn allowing it to turn a precise amount. Unlike the original form used in early pendulum clocks, the anchor escapement permitted the pendulum to travel in a very small arc. Moreover, this invention allowed the use of a long pendulum which could beat once a second and thus led to the development of a new floorstanding case design, which became known as the grandfather clock.

HToday, highly accurate timekeeping instruments set the beat for most electronic devices. Nearly all computers contain a quartz- crystal clock to regulate their operation. Moreover, not only do time signals beamed down from Global Positioning System satellites calibrate the functions of precision navigation equipment, they do so as well for mobile phones, instant stock- trading systems and nationwide power- distribution grids. So integral have these time- based technologies become to day- to- day existence that our dependency on them is recognised only when they fail to work.