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  • 科学的性质

     

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    Why Does a Moose Have Antlers?
    ::为什么摩斯人有鹿角?

    Did you ever wonder why a moose grows large antlers? The antlers may grow as wide as 1.8 m (6 ft) from tip to tip! The antlers require  a lot of energy to grow and carry around. They can even get caught in brush and trees. In these ways, they would seem to be more of a detriment than a help, so what purpose do the antlers serve? And why do only male moose grow them? If you've ever asked questions such as these about the natural world, then you are already  thinking like a scientist.
    ::你有没有想过,为什么一只驼鹿会长成大鹿角?鹿角从小到小可能长到1.8米(6英尺)的宽度?鹿角需要大量的能量才能生长和携带。它们甚至可以被树和树抓住。从这些方面看,它们似乎比帮助更有害,所以鹿鹿的作用是什么呢?为什么只有雄驼才能种植它们?如果你曾经问过关于自然世界的问题,那么你就已经像科学家一样思考了。

    Defining Science
    ::科学定义

    Science is a distinctive way of gaining knowledge about the natural world that starts with a question and then tries to answer the question using   evidence and logic. It  is an exciting exploration of all the whys and hows that any curious person might ask  about the world. You can be part of that exploration! Besides your curiosity, all you need is a basic understanding of how scientists think and how science is done. In this concept, you'll learn how to think like a scientist.
    ::科学是获取自然世界知识的独特方式,它从一个问题开始,然后试图用证据和逻辑来回答问题。它是一个令人兴奋的探索,探索任何好奇的人可能问世界的所有原因和方式。你可以参与这一探索。除了你的好奇心外,你所需要的只是对科学家如何思考和如何完成科学的基本理解。在这个概念中,你会学习如何像科学家一样思考。

    Thinking Like a Scientist
    ::像科学家一样思考

    Thinking like a scientist rests on certain underlying assumptions. Scientists assume that:
    ::像科学家一样思考取决于某些基本假设。

    • Nature can be understood through systematic study.
      ::自然可以通过系统研究来理解。
    • Scientific ideas are open to revision.
      ::科学思想可以修改。
    • Sound scientific ideas withstand the test of time.
      ::健全的科学思想经得起时间的考验。
    • Science cannot provide answers to all questions.
      ::科学不能为所有问题提供答案。

    Nature Is Understandable
    ::大自然是可以理解的

    Scientists think of nature as a single system controlled by natural laws. By discovering natural laws, scientists strive to increase their understanding of the natural world. Laws of nature are expressed as scientific laws. A scientific law is a statement that describes what always happens under certain conditions in nature.
    ::科学家们将自然视为受自然法控制的单一系统。通过发现自然法,科学家们努力增进他们对自然界的了解。自然法则被表述为科学法。科学法是一种描述在自然性质的某些条件下总是发生的事情的声明。

    of Inheritance fall into the category of scientific laws. These laws were discovered by an Austrian Monk named Gregor  ( pictured ) in the mid-1800s, and the laws describe how certain traits are inherited from parents by their offspring. Although Mendel discovered his laws of inheritance by experimenting with , we now know that they  apply to many other organisms , including humans. The laws describe how we inherit relatively simple genetic traits, such as , from our parents. For example, if you know the types of your parents, you can use Mendel's laws to predict your chances of having a particular blood type.
    ::遗产继承属于科学法律的范畴。 这些法律是由一个名为Gregor(想象中的)的奥地利僧侣在1800年代中期发现的, 法律描述了某些特征是如何从父母的后代继承的。 虽然Mendel通过实验发现了继承法, 我们现在知道它们适用于许多其他生物, 包括人类。 法律描述了我们如何继承相对简单的遗传特征, 比如我们父母的遗传特征。例如,如果你知道父母的种类, 你可以使用Mendel的法律来预测你是否拥有某种血型。

    lesson content
    Gregor Mendel discovered laws of inheritance in the mid-1800s. The laws have since been refined, but they still apply in many instances.

    Scientific Ideas Are Open to Change
    ::开放改变科学理念

    Science is both  a process and  body of knowledge.  Scientific k nowledge is generated through systematic processes, such as observation and experimentation.  Scientists are always testing and revising their ideas, and as new observations are made, existing ideas may be challenged. Ideas may be replaced with new ideas that better fit the facts, but more often, existing ideas are simply revised. For example, when scientists discovered how genes control genetic traits, they didn't throw out Mendel's laws of inheritance. The new discoveries helped explain why Mendel's laws applied to certain traits but not others. They showed that Mendel's laws are part of a bigger picture. Through many new discoveries over time, scientists gradually build an increasingly accurate and detailed understanding of the natural world.
    ::科学既是一个过程,也是一个知识体。科学知识是通过系统过程,例如观察和实验产生的。科学家们总是在测试和修改他们的想法,随着新的观察,现有的想法可能会受到挑战。想法可能会被更符合事实的新想法所取代,但更经常的是,现有的想法会被简单地修改。例如,科学家们发现基因是如何控制遗传特征的,他们并没有抛弃Mendel的继承法则。新的发现有助于解释为什么Mendel的法律适用于某些特征,而不适用于其他特征。他们表明Mendel的法律是大图中的一部分。随着时间的推移,通过许多新的发现,科学家逐渐形成了对自然界的日益准确和详细的了解。

    Occasionally, scientific ideas change radically. In 1962, philosopher Thomas Kuhn began calling these radical changes in scientific ideas paradigm shifts . Kuhn agreed that scientific knowledge typically accumulates gradually as new details are added to established theories . However, Kuhn also argued that from time to time, a scientific revolution occurs in which current theories are abandoned and completely new ideas take their place.
    ::偶尔,科学理念会发生急剧变化。 1962年,哲学家库恩(Thomas Kuhn)开始呼吁科学理念范式转变的这些根本变化。 库恩(Kuhn)同意科学知识通常会随着新细节加入既定理论而逐渐积累。 然而,库恩(Kuhn)也认为,不时发生科学革命,在这场革命中,当前理论被抛弃,完全新的理念取代。

    Although there is debate among scientists as to what constitutes a paradigm shift, the is widely accepted as a good example in biology . In fact, some scientists argue that it is the only example of a paradigm shift in this field of science . Prior to Charles Darwin's publication of his theory of evolution in the 1860s, most scientists believed that God had created living and that the species then existing on Earth had not changed since they were created. Drawing on a great deal of evidence and logical arguments, demonstrated that species could change and that new species could arise from pre-existing ones. This was such a radical change in scientific thinking that Darwin was reluctant to publish his ideas for fear of a backlash from other scientists and the public. Indeed, Darwin was at first ridiculed for his evolutionary theory, but in time, it was widely accepted and became a cornerstone of all life sciences.
    ::尽管科学家们对什么是范式转变有争论,但这种转变被广泛接受为生物学的好榜样。事实上,一些科学家认为这是这个科学领域范式转变的唯一例子。 在查尔斯·达尔文发表1860年代的进化理论之前,大多数科学家认为上帝创造了生命,而当时地球上存在的物种自创立以来并没有改变。 大量证据和逻辑论据表明物种可以改变,新的物种可能来自先前存在的物种。 科学思维的这种根本变化使得达尔文不愿意发表他的观点,因为害怕其他科学家和公众的反弹。 事实上,达尔文最初被其进化理论所嘲弄,但后来却被广泛接受,并成为所有生命科学的基石。

    Scientific Knowledge May Be Long Lasting
    ::科学知识可能是长期的

    Many scientific ideas have stood  the test of time. About 200 years ago, the scientist John Dalton proposed atomic theory — the theory that all matter is made of tiny particles called atoms. This theory is still valid today. During the two centuries since the theory was first proposed, scientists have  learned a lot more about atoms and the even smaller particles that compose them . Nonetheless, the idea that all matter consists of atoms remains valid. There are many other examples of basic scientific  ideas that have been tested repeatedly and proven sound. You will learn about many of them as you study human biology.
    ::许多科学思想经受了时间的考验。大约200年前,科学家约翰·道尔顿提出了原子理论 — — 即所有物质都由微小粒子组成的理论叫做原子。这一理论在今天仍然有效。自首次提出理论以来的两个世纪里,科学家们对原子和形成原子的较小粒子有了更多的了解。尽管如此,所有物质都由原子构成的想法依然有效。还有其他许多基本科学思想的例子,这些基本科学思想已经多次得到检验并证明是健全的。你们在研究人类生物学时将会了解其中的许多。

    Not All Questions Can be Answered by Science
    ::科学并不能回答所有问题

    Science rests on evidence and logic, and evidence comes from observations. Therefore, science deals only with things that can be observed. An observation is anything that is detected through human or with instruments or measuring devices that extend human senses. Things that cannot be observed or measured by current means — such as supernatural beings or events — are outside the bounds of science. Consider these two questions about life on Earth:
    ::科学基于证据和逻辑,证据来自观测,因此,科学只涉及可以观测到的东西,观测是指通过人类或仪器或测量装置探测到的、能够扩大人类感官的任何事物,无法通过现有手段(如超自然生物或事件)观察或测量的事物不属于科学的范围。

    • Did life on Earth evolve over time?
      ::地球上的生命随着时间的流逝而演变吗?
    • Was life on Earth created through another method?
      ::地球上的生命是通过另一种方法创造的吗?

    The first question can be answered by science on the basis of scientific evidence (such as and logical arguments). The second question could be a matter of belief, but no evidence can be gathered to support or refute it. Therefore, it is outside the realm of science.
    ::第一个问题可以科学依据科学证据(如逻辑论据)回答。 第二个问题可能是一个信仰问题,但无法收集任何证据来支持或反驳它。 因此,它不属于科学范畴。

    Feature: Human Biology in the News
    ::特著:《新闻》中的人类生物学

    Scientific research is often reported in the popular media. In fact, that's how most people learn about new scientific findings. Informing the public about scientific research is a valuable media service, but the types of scientific investigations that are reported may lead to a distorted public perception of what science is and how reliable its results are. Why? There are actually two types of science, often referred to as consensus science and frontier science. The latter type of science is the type that usually makes the news, but the media generally do not distinguish between the two types. As a result , consumers may infer that what they read about frontier science is typical of all science.
    ::公众媒体经常报道科学研究。事实上,大多数人都是通过这种方式了解新的科学发现。向公众提供科学研究信息是一种有价值的媒体服务,但所报道的科学调查类型可能导致公众对科学是什么及其结果的可靠性的扭曲认识。为什么?实际上有两种科学类型,通常被称为共识科学和前沿科学。后一种科学是通常产生新闻的类型,但媒体一般不区分这两种类型。因此,消费者可以推断他们所读到的关于前沿科学的东西是所有科学的典型。

    Consensus science refers to scientific ideas that have been researched for a long period of time and for which a great deal of evidence has accumulated. This type of research generally fits well within current scientific paradigms. A good example of consensus science is global climate change. Data shows that human activities have caused  increasing levels of atmospheric carbon dioxide. The problems associated with have been accumulating for many decades. Today, virtually all climate scientists agree that global warming is occurring and that human actions are largely responsible for it. However, the few scientists  —  and many politicians  —  who do not agree with the consensus view receive greater media attention because the consensus view is "old" news. The findings have been coming in for years, and new research in the area keeps finding similar results.
    ::共识科学是指长期研究并积累了大量证据的科学思想,这种研究在目前的科学范式中通常很适合。共识科学的一个良好例子是全球气候变化。数据表明人类活动已造成大气二氧化碳水平的上升。与这些问题有关的问题已经累积了几十年。今天,几乎所有气候科学家都同意全球变暖正在发生,人类行动在很大程度上要对此负责。然而,少数科学家——以及许多政治家——不同意共识观点的人——受到媒体更多的关注,因为共识观点是“古老的”新闻。研究结果已经持续多年,该领域的新研究也不断发现类似的结果。

    Frontier science, in contrast, refers to scientific ideas that are relatively new and have not yet been supported by years of scientific evidence. Frontier research takes place at the frontiers of knowledge in a particular field. A good example of frontier science is research into the presumed link between cholesterol in the diet and cholesterol in the . The consensus view for many years was that a diet high in cholesterol increases blood levels of cholesterol, which may lead, in turn, to . Recent research challenging this accepted view found that genes play a more significant role than diet in blood levels of cholesterol and risk of cardiovascular disease.
    ::相比之下,前沿科学则是指相对新颖的科学思想,这些思想尚未得到多年科学证据的支持。前沿研究是在特定领域的知识前沿进行的。前沿科学的一个良好例子是研究饮食中的胆固醇与胆固醇之间的假定联系。多年来的共识是,胆固醇含量高的饮食会增加胆固醇的血液水平,而这反过来又可能导致胆固醇的血液水平。最近对这个公认的观点提出挑战的研究发现,基因在胆固醇血液水平和心血管疾病风险方面所起的作用比饮食更为重要。

    The media tend to focus on frontier science because it seems controversial and may lead to major new scientific breakthroughs. With more research, ideas in frontier science may be supported by more evidence, gain wider acceptance, and become consensus science. In some cases, frontier science that is at odds with a current paradigm initially may lead to a paradigm shift.
    ::媒体倾向于关注前沿科学,因为它似乎具有争议性,并可能导致新的重大科学突破。 随着更多的研究,前沿科学理念可能得到更多证据的支持,获得更广泛的接受,并成为共识科学。 在某些情况下,与当前模式相悖的前沿科学最初可能导致范式转变。

    The opposite could also  happen. Additional research may undermine the initial findings of frontier research so that the new and exciting ideas are rejected. Unfortunately, when frontier science is later shown to be mistaken, people may infer that all science, including consensus science, is unreliable.
    ::反之亦然。 更多的研究可能会破坏前沿研究的初步发现,从而拒绝新的刺激思想。 不幸的是,当前沿科学后来被证明是错误的时,人们可能会推断所有科学,包括共识科学,都不可靠。

    Another example of frontier science is research purporting to show that certain childhood vaccines cause autism. Check out the video    to start learning more about this research and how mainstream, popular media reports about it continue to influence public behavior, even though the research findings have since been debunked. 
    ::另一个前沿科学的例子是旨在显示某些儿童疫苗导致自闭症的研究。 查看视频以开始更多了解这项研究,以及主流大众媒体关于这项研究的报道如何继续影响公众行为,尽管研究结果已经被揭穿。

     Summary
    ::摘要

    • Science is a distinctive way of gaining knowledge about the natural world that tries to answer questions using  evidence and logic.
      ::科学是获取关于自然世界知识的独特方式, 自然世界试图用证据和逻辑回答问题。
    • Scientists assume that nature can be understood  through systematic study.
      ::科学家认为,可以通过系统研究来理解大自然。
    • Scientific ideas are open to revision.
      ::科学思想可以修改。
    • Sound scientific ideas withstand the test of time.
      ::健全的科学思想经得起时间的考验。
    • Science cannot provide answers to all of our questions.
      ::科学不能为我们的所有问题提供答案。

    Review
    ::回顾

    1. Define science.
    ::1. 界定科学。

    2. What is the general goal of science?
    ::2. 科学的总体目标是什么?

    3. Identify four basic assumptions that scientists make when they study the natural world.
    ::3. 确定科学家在研究自然界时作出的四项基本假设。

    4. Explain why science cannot provide answers to all questions.
    ::4. 解释为什么科学不能回答所有问题。

    5. Do observations in science have to be made by the naked eye? Can you think of a way in which scientists might be able to make observations about something they cannot directly see?
    ::5. 科学观测是否必须由肉眼进行?你能想象科学家能够以何种方式对他们无法直接看到的东西进行观测吗?

    6. If something cannot be observed, can it be tested scientifically? Explain your reasoning.
    ::6. 如果无法观察到某种东西,能否进行科学检验?解释一下你的推理。

    7. What do you think would be more susceptible to being disproven: conclusions drawn from frontier science or consensus science? Explain your reasoning.
    ::7. 你认为哪些比较容易被推翻:来自前沿科学或协商一致科学的结论? 解释你的推理。

    8. Scientific knowledge builds upon itself. Give an example of a scientific idea from the reading where the initial idea developed further  as science advanced.
    ::8. 科学知识是建立在自身基础上的,从最初的理念随着科学的进步而进一步发展的解读中,举了一个科学理念的例子。

    9. A dramatic change in scientific understanding is called a ________ _________ .
    ::9. 科学理解的戏剧性变化被称为 ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

    10. Discuss this statement: “ S cientific ideas are always changing, so they can't be trusted.” Do you think this is true?
    ::10. 讨论本声明: " 科学思想总是在变化,因此不能相信。 " 你认为这是真的吗?

    11.  True or False:  S cience is  both a process and a body of knowledge.
    ::11. 真实或虚假:科学既是一个过程,也是一个知识体。

    12. True or False:  A scientific law describes what happens most of the time under certain conditions.
    ::12. 真实或假:科学法描述了在特定条件下大多数时间发生的事情。

    13. What is one piece of evidence that's been found to suggest that life on Earth evolved over time?
    ::13. 发现哪些证据表明地球上的生命随着时间的流逝而演变?

    14. Why do you think that scientific knowledge expands as technology becomes more advanced?
    ::14. 为什么你认为随着技术的更先进,科学知识会扩大?

    Explore More
    ::探索更多

    This video illuminates why we must learn to have a critical eye regarding scientific studies and information.
    ::这段视频说明了为什么我们必须学会对科学研究和信息持批判态度。