{"id":79,"date":"2021-01-25T00:52:49","date_gmt":"2021-01-25T00:52:49","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/suny-hccc-generalscience\/?post_type=chapter&p=79"},"modified":"2021-01-25T00:53:04","modified_gmt":"2021-01-25T00:53:04","slug":"2-experimentation-in-scientific-research","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/suny-hccc-generalscience\/chapter\/2-experimentation-in-scientific-research\/","title":{"raw":"2. Experimentation in Scientific Research","rendered":"2. Experimentation in Scientific Research"},"content":{"raw":"
\r\n\r\nAnyone who has used a cellular phone knows that certain situations require a bit of research: If you suddenly find yourself in an area with poor phone reception, you might move a bit to the left or right, walk a few steps forward or back, or even hold the phone over your head to get a better signal. While the actions of a cell<\/a> phone user might seem obvious, the person seeking cell phone reception is actually performing a scientific experiment: consciously manipulating one component (the location of the cell phone) and observing the effect of that action on another component (the phone's reception). Scientific experiments<\/a> are obviously a bit more complicated, and generally involve more rigorous use of controls<\/a>, but they draw on the same type of reasoning that we use in many everyday situations. In fact, the earliest documented scientific experiments were devised to answer a very common everyday question: how vision works.\r\n\r\n<\/div>\r\n
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A brief history of experimental methods<\/h2>\r\n
\"Alhazen\" <\/a>
Figure 1: Alhazen (965-ca.1039) as pictured on an Iraqi 10,000-dinar note<\/figcaption><\/figure>\r\nOne of the first ideas regarding how human vision works came from the Greek philosopher Empedocles<\/a> around 450 BCE<\/a>. Empedocles reasoned that the Greek goddess Aphrodite had lit a fire in the human eye, and vision was possible because light<\/a> rays from this fire emanated from the eye, illuminating objects around us. While a number of people challenged this proposal, the idea that light radiated from the human eye proved surprisingly persistent until around 1,000 CE<\/a>, when a Middle Eastern scientist advanced our knowledge of the nature of light and, in so doing, developed a new and more rigorous approach to scientific research<\/a>. Ab\u016b 'Al\u012b al-Hasan ibn al-Hasan ibn al-Haytham, also known as Alhazen<\/a>, was born in 965 CE in the Arabian city of Basra in what is present-day Iraq. He began his scientific studies in physics, mathematics, and other sciences after reading the works of several Greek philosophers. One of Alhazen's most significant contributions was a seven-volume work on optics titled Kitab al-Manazir<\/em> (later translated to Latin as Opticae Thesaurus Alhazeni \u2013 Alhazen's Book of Optics<\/em>). Beyond the contributions this book made to the field of optics, it was a remarkable work in that it based conclusions on experimental evidence<\/a> rather than abstract<\/a> reasoning \u2013 the first major publication to do so. Alhazen's contributions have proved so significant that his likeness was immortalized on the 2003 10,000-dinar note issued by Iraq (Figure 1).\r\n\r\nAlhazen invested significant time studying light<\/a>, color, shadows, rainbows, and other optical<\/a> phenomena. Among this work was a study in which he stood in a darkened room with a small hole in one wall. Outside of the room, he hung two lanterns at different heights. Alhazen<\/a> observed that the light from each lantern illuminated a different spot in the room, and each lighted spot formed a direct line with the hole and one of the lanterns outside the room. He also found that covering a lantern caused the spot it illuminated to darken, and exposing the lantern caused the spot to reappear. Thus, Alhazen provided some of the first experimental evidence<\/a> that light does not emanate from the human eye but rather is emitted by certain objects (like lanterns) and travels from these objects in straight lines. Alhazen's experiment<\/a> may seem simplistic today, but his methodology<\/a> was groundbreaking: He developed a hypothesis<\/a> based on observations<\/a> of physical relationships (that light comes from objects), and then designed an experiment to test that hypothesis. Despite the simplicity of the method<\/a>, Alhazen's experiment was a critical step in refuting the long-standing theory<\/a> that light emanated from the human eye, and it was a major event in the development of modern scientific research<\/a> methodology.\r\n
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Comprehension Checkpoint<\/p>\r\n

Why is Alhazen's work considered a major event in the development of modern scientific research methodology?<\/p>\r\n\r\n

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