首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The movement of the sun creates periods of________.
The movement of the sun creates periods of________.
admin
2022-11-25
79
问题
The movement of the sun creates periods of________.
W: Dr. Smith, how did early humans start to note, or record the passing of time?
M: Well, this is a long story. No one knows what time itself is. But we can notice its passing in a number of ways. In early human history, the only changes that seemed to repeat themselves evenly were the movements of objects in the sky. The most easily seen result of these movements was the difference between light and darkness.
The sun rises in the eastern sky, producing light. It moves across the sky and sinks in the west, causing darkness. The periods of light and darkness it created were the first accepted periods of time. We have named each period of light and darkness—one day.
People saw the sun rise higher in the sky during the summer than in winter. They counted the days that passed from the sun’ s highest position until it returned to that position. They counted 365 days. We now know that is the time Earth takes to move once around the sun. We call this period of time a year.
W: I am sure the moon was also very important to our ancestors.
M: Yes, of course. Early humans also developed a way to use the changing faces of the moon to tell the time.
The moon was "full" when its face was bright and round. The early humans counted the number of times the sun appeared between full moons. They learned that this number always remained the same—about 29 suns. 29 suns equaled one moon. We now know this period of time as one month.
As early humans learned to plant seeds and grow crops, they had to know when the seasons would change. So, they developed calendars. No one knows when the first calendar was developed. But it seems possible that it was based on moons, or lunar months.
The divisions of time we use today were developed in ancient Babylonia 4,000 years ago. Babylonian astronomers believed the sun moved around the Earth every 365 days. They divided the trip into twelve equal parts, or months. Each month was thirty days. Then, they divided each day into 24 equal parts, or hours. They divided each hour into sixty minutes , and each minute into 60 seconds.
Humans have used many devices to measure time. The sundial was one of the earliest and simplest. A sundial measures the movement of the sun across the sky each day. It has a stick or other object that rises above a flat surface. The stick, blocking sunlight, creates a shadow. As the sun moves, so does the shadow of the stick across the flat surface. Marks on the surface show the passing of hours, and perhaps, minutes.
W: But the sundial works well only when the sun is shining. So, what are the other ways to measure the passing of time?
M: Of course. One device is the hourglass. It uses a thin stream of falling sand to measure time. The hourglass is shaped like the number eight wide at the top and bottom, but very thin in the middle. In a true " hour" glass, it takes exactly one hour for all the sand to drop from the top to the bottom through a very small opening in the middle. When the hourglass is turned with the upside down, it begins to mark the passing of another hour.
By the 18th century, people had developed mechanical clocks and watches. And today, many of our clocks and watches are electronic.
So, we have devices to mark the passing of time. But what time is it now? Clocks in different parts of the world do not show the same time at the same time. This is because time on Earth is set by the sun’s position in the sky above.
As international communications and travel increased, it became clear that it would be necessary to establish a common time for all parts of the world.
In 1884, an international conference divided the world into 24 time areas, or zones. Each zone represents one hour. The astronomical observatory in Greenwich, England, was chosen as the starting point for the time zones. Twelve zones are west of Greenwich. Twelve are east. The time at Greenwich—as measured by the sun—is called Universal Time. For many years it was called Greenwich Mean Time.
W: That brings us to the modern time. Thanks very much, Dr. Smith.
选项
答案
shadow
解析
转载请注明原文地址:https://kaotiyun.com/show/x40D777K
本试题收录于:
公共英语五级笔试题库公共英语(PETS)分类
0
公共英语五级笔试
公共英语(PETS)
相关试题推荐
Countriesmustcreativelycomplementtheuseoffossilfuelsandrenewableenergyintheinterimpendingwhenrenewableenergyc
Whilemanyworkersarewillingtolearnnewskillsorcompletelyretraintoimprovetheirfutureemployability,fewfeeltheyar
Despitehelpingtorecordevents,photoscoulddamageourmemories.Researchersfoundpeoplewhotakepictureshave【C1】________r
Despitehelpingtorecordevents,photoscoulddamageourmemories.Researchersfoundpeoplewhotakepictureshave【C1】________r
Despitehelpingtorecordevents,photoscoulddamageourmemories.Researchersfoundpeoplewhotakepictureshave【C1】________r
Despitehelpingtorecordevents,photoscoulddamageourmemories.Researchersfoundpeoplewhotakepictureshave【C1】________r
Nowadays,amateurphotographyhasbecomeatroublingissue.Citizensofrichcountrieshavegotusedtobeingwatchedbyclosed-
Themovementofthesuncreatesperiodsof________.
Althoughthewomen’srightsmovementintheUnitedStatesisthoughtofasarecentdevelopment,itsbeginningsdatebackover
Progressiveandreactionarypopulistmovementsarenotnecessarily________:eachmay,andusuallydoes,possessthefeaturesof
随机试题
Whatisyourfavoritecolor?Doyoulikeyellow,orangeorred?Ifyoudo,youmustbeanoptimist(乐观者),aleader,anactivepe
A、Heshouldgotothelibrary.B、Heshouldturntohisprofessorforhelpduringofficehours.C、Heshouldsetofficehoursfor
目前诊断应为患者的血红蛋白降低
在每年的安全生产事故统计中可以发现,触电事故造成的死亡人数占据非常大的比例,每年由于触电造成的死亡人数超过8000人。触电事故具有一定的特性,下列关于触电事故的特性,说法正确的是()。
王某是一公司的高管。其2岁的儿子一直由姥姥照顾。因姥姥已年届70岁,身体有些行动不便故户外活动较少。最近发现孩子盗汗、夜间常常惊醒。形成枕秃。请根据上述描述回答以下问题:如何进行诊断?
大学生小王在一次外出时不幸发生了车祸,造成下肢骨折。住院治疗1个月后,他希望出院,但他的下肢还没有完全康复。社会工作者对他的情况进行了评估,发现他的家在五楼,没有电梯,父母在外地工作,没有人可以照顾他。因此,社会工作者帮助他联系了社区里的一间一楼的房间供他
兴趣的迁移是指将已有的兴趣延伸到相关的事物上,对该事物也发生兴趣。兴趣的迁移需要满足以下哪些条件?()
全面深化改革的总目标是完善和发展中国特色社会主义制度,推进国家治理体系和治理能力现代化。()
习近平总书记在考察时强调,只要还有一家一户乃至一个人没有解决基本生活问题,我们都不能___________;只要群众对幸福生活的还没有变成现实,我们都要毫不懈怠团结带领群众一起奋斗。填入画横线部分最恰当的一项是:
删除视图stuvw的命令是()。
最新回复
(
0
)