CHAPTER ONE Using Tools in Science We all use tools to get things done To eat soup we use a spoon To move a heavy box we use a cart To sign our name we use a pen Every tool large or small exists to do a job DID YOU KNOW Tools have been helping people throughout history Spears and arrows aided ancient hunters Early farmers made use of simple plows For writing people once used hollow reeds and wing feathers 4
Tools Extend Us Tools allow us to do things beyond our natural abilities Some tools extend our physical strength our reach and our speed Other tools expand the limits of our senses Still others provide us with added brain power The tools we use to measure things help increase our understanding of the world 5
The Right Tool Without the right tool many tasks are difficult or impossible But a useful tool can inspire people to use it in various ways One tool is not suited for all purposes though So inventors are always designing new and better tools for specific jobs Scientific knowledge DID YOU KNOW The term technology applies to any practical use of scientific knowledge Many nations are technologically advanced because the lifestyles of their contributes to the invention of some tools The light bulb for instance would not exist without knowledge of electricity Likewise earlier scientific discoveries made engines televisions and microwave ovens possible citizens depend on technology 6
PAST TO PRESENT PAST TELEVISION TV networks send television signals through the air at the speed of light Today all TV signals in the United States are a digital signal PAST PRESENT MUSIC PLAYER Audiotapes store music as magnetioc signals Compact discs CDs and digital files store it as data All music players convert stored material back into sound PRESENT PAST LIGHT BULB All light bulbs use electric power to produce light The latest types of bulbs have been improved to use less electricity to produce light PRESENT PRESENT CELL PHONE Every cell phone uses radio waves to send and receive messages Voice text picture and video messages are common on today’s cell phones PAST 7
