閱讀的其中一本與本年度親子「悅」讀計劃的主題 — 「生活小博士」有關的中文書或英文書，並按題目寫一篇讀後感。
What does time mean to you? Do you use it well, even though you can’t feel it, see it or touch it? Also, have you ever imagined what the world would be like if we did not measure time? This book introduces you to the world of time and how measurements of time were invented.
In Ancient Egypt, farmers noted that the Nile River flooded every summer, and they planted their crops after the flood. From their observations, they knew that the flood occurred about every 365 days, so they made that their year. This was one of the first origins of the calendar.
The Egyptians also developed one of the first clocks. They used sunlight together with shadow to measure time. When the sun is low, the shadows are long. As the sun rises, the shadows become shorter. This founded the basis for the sundial, the first clock ever invented.
Moreover, scientists can now determine the age of an ancient fossil through carbon-dating, which was developed in the 1940s. All living things constantly take in carbon, from activities like photosynthesis to eating plants and meats. When the organism dies, it stops taking in new carbon, and some of the carbon (carbon-14, which is radioactive) in its system begins to decay. By measuring the percentage of carbon-14 remaining in a fossil, scientists can determine approximately how many years have passed since the organism died.
Another fascinating area of the book was jetlag. When Earth orbits the Sun, the planet is spinning in a clockwise direction and the Sun only shines on one side, leaving the other side in the dark. As the earth spins each hour, sunlight falls on different parts of the world. To mark the time in each part of the Earth, the planet is divided into 24 imaginary lines running from the North Pole to the South Pole, called meridians. Since the headquarters of this research was in Greenwich, scientists marked Greenwich as the Prime Meridian. As an example, if the time in Greenwich is one o’clock, and another city is two meridians away, in that city it is three o’clock. Your body has an inner clock that is tuned to your home city’s time. When you travel, it may be 7am at your new city, but it may only be 3am at your home town. Your body would not yet be ready to wake up at 3am, so you would feel very tired for a few days, until your inner clock had time to catch up with your new city. This is called jetlag.
This book has taught me that since the ancient times, we have observed and learned different ways to measure time so we can better understand how nature works, and how to manage it.
A. 是保暖用的圍巾。 B.是進食後的擦嘴布。 C.是穿西裝時的裝飾物。