Scientific Theories
In science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. A useful theory, in addition to explaining past observations, helps to predict events that have not as yet been observed. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves are not science. As the mathematician Jules Henri Poincare said,Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house. Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hypothesis is a leap into the unknown. It extends the scientists thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. Without hypothesis, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories.
基础练习对于雅思阅读的重要性
雅思阅读考前一个月要多积累词汇量
细数G类雅思阅读考试的几大特点(四)
利用零散时间攻克雅思阅读词汇量
如何应对雅思阅读的辨别正误题型
针对中高级水平考生的雅思阅读备考方法
浅析“无词阅读法”对雅思阅读直接效果(一)
雅思阅读全方位提升攻略
浅析“无词阅读法”对雅思阅读直接效果(三)
雅思写作思路抛砖:养老谁负责
针对中高级水平考生的雅思阅读备考方法
简析基础练习对于雅思阅读的重要性
雅思阅读答题方法解析:辨别正误题型
雅思阅读T/F/NG与Y/N/NG的简写争论
攻克雅思阅读考试的五大心法
雅思阅读技巧:利用关键词定位
雅思快速定位法——段落+词汇
雅思阅读高分技巧指导
四个月突破雅思阅读的备考方法
剑九雅思阅读 内容实质并无大变化
那些藏在眼皮底下的雅思阅读答案
雅思阅读高分技巧指导
雅思阅读中的T/F/NG的快速判断法
雅思阅读判断题Not Given考点分析(下)
什么是平行阅读法?
雅思阅读技巧三种读
雅思小作文写作资料
简析基础练习对于雅思阅读的重要性
雅思阅读与托福阅读、GRE阅读的区别
制胜雅思阅读题型的三条备考策略
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |