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
Why roses are red and violets are blue? Did you ever wonder why you see the colors you do or if other animals see the same co
Why roses are red and violets are blue? Did you ever wonder why you see the colors you do or if other animals see the same co
admin
2010-06-18
21
问题
Why roses are red and violets are blue?
Did you ever wonder why you see the colors you do or if other animals see the same colors that you see? We see light that bounces off of things around us. When the light enters our eyes, special cells tell our brains about the light. These cells are called photoreceptors. Light is made of little bits called photons. When the sun shines, trillions and trillions of these little bits of light fall on the earth. The photons bounce off of almost everything and some of them enter our eyes. Those bits that enter our eyes allow us to see. So, where does the color come from?
Starting in the 1600s with Sir Isaac Newton, scientists have believed that there are different kinds of photons. Different types give rise to our sense of colors. The different photons are said to have different wavelengths. Sunlight contains all the different wavelengths of photons. The visible wavelength colors can be seen when you look at a rainbow. Raindrops acting as natural prisms produce the colors.
HOW do our photoreceptors work?
We have two main types of photoreceptors called rods and cones. They are called rods and cones because of their shapes. These cells are located in a layer at the back of the eye called the retina. Rods are used to see in very dim light and only show the world to us in black and white. This is why you see only black and white when you are outside in the evening or in a dimly lit room. The other type of photoreceptors, the cones, allow us to see colors. They are not as sensitive as the rods so they only work in bright light. There are three types of cones, one for each of the three main colors we see, red, green and blue.
Some people have a genetic defect that makes one or more of the cones fail. This condition is known as color deficiency. You may have heard it called color blindness. Color blindness is fairly common, affecting about nine percent of all humans.’ It is much more common in men than in women. To test for color blindness a special picture called an Ishihara test is used.
What about other animals? What kind of colors do they see? Most animals see fewer colors than we do, but some see more! We know this by looking at how many kinds of cone
photoreceptors they have. Another good indication of what an animal can see is by looking at their own colors. The colors of their prey are also an indication of an animals ability to see color.
What three primary colors do we see?
选项
A、Red, white, and blue.
B、Red, green, and yellow.
C、Red, green, violet.
D、Red, green, blue.
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/YJlO777K
0
专业英语八级
相关试题推荐
Etiquette1Insixteenth-centuryItalyandeighteenth-centuryFrance,waningprosperityandincreasingsocialunrestledthe
______dealswithMarx’sintellectualimpact.Thechapterthatdiscussesanimportantsourceoflearninginhigh-technologyindu
Nancybecameataxidriverbecause
WhichofthefollowingstatementsisINCORRECTaboutDavid’spersonalbackground?
1Doyoueverfeelasthoughyouspendallyourtimeinmeetings?2HenryMintzberg,inhisbookTheNatureofManageria
IftheFederationofAmericanScientistsmadealistofeducationalvideogames,youmightexpecttofindOregonTrai,theStory
Theholidaybeganasawaytohonorsoldierskilledduring______.
A、murderB、burglarywithintenttomurderC、slayingD、robberyB
Theold-agepaternalismofsouthernCanadiansoverEskimoshasdiedmoreslowlyintheruralvillageswhereEskimoshavebeenmo
随机试题
下列物质可降低氯己定杀菌作用的是
女性,69岁。有高血压史10余年,平时坚持服用抗高血压药物。入院前6小时在看电视时突然感右上下肢麻木、乏力、说话口齿不清、口水外流、头痛,呕吐1次后呈嗜睡状态,送入急诊。入院时BP26/14kPa(195/105mmHg)。当诊断明确后,此时最合
类风湿关节炎患者X线摄影体位中首选
A.肱骨髁上伸直型骨折B.肱骨干骨折C.桡骨远端骨折D.锁骨骨折E.尺骨上1/3骨折前臂缺血性肌挛缩多见于
()不得招聘为证券交易所的从业人员。
下列选项中不属于广义信贷期限的是()。[2010年5月真题]
某大型工程项目由政府投资建设,业主委托某招标代理公司代理施工招标。招标代理公司确定该项目采用公开招标方式招标。招标公告在当地政府规定的招标信息网上发布。招标文件中规定:投标担保可采用投标保证金或投标保函方式担保。评标疗法采用经评审的最低投标价法。投标有效期
学校文化最终要表达这样一些内容:()。
科学家研制出一种无针注射器,这种注射器的注射原理最可能是:
Ifyouweretobeginanewjobtomorrow,youwouldbringwithyousomebasicstrengthsandweaknesses.Successor【C1】______iny
最新回复
(
0
)