The New Childrens Encyclopedia
240 SCIENCE Light fantastic Energy takes many forms. Light is one we are familiar with because our eyes are specially adapted to ...
LIGHT FANTASTIC 241 SCIENCE REFRACTION When light crosses the boundary between two media with different densities (such as air a ...
Spectrum The universe is full of electro- magnetic radiation, which travels in waves. Our eyes see a small range of these waves ...
SPECTRUM SCIENCE COLOR VISION Color vision Objects appear colored to our eyes because their surfaces reflect some wavelengths of ...
244 Evolution Over long periods of time, all species of organism slowly change. This gradual change, called evolution, is driven ...
EVOLUTION 245 DNA This complicated chemical is the blueprint for life. Slight alterations in an organism’s DNA can result in ge ...
Genes and DNA Unless you are an identical twin, your body is built according to a unique set of biological instructions, your ow ...
GENES AND DNA SCIENCE Genetic diseases Some genes contain errors that cause them to malfunction. These faulty genes can cause di ...
248 SCIENCE CRIME SCENE DO NOT ENTER CRIME SCENE Forensic science Forensic science helps the police fight crime. Most people thi ...
FORENSIC SCIENCE 249 SCIENCE TAKE A LOOK: FACE FROM THE PAST u DEPTH MARKERS The artist makes a cast of the skull. Pegs act as d ...
TECHNOLOGY When was the hot-air balloon invented? Find out on page 254 What is the range of the Venturi Astrolab? Find out on pa ...
How does a digital camera work? Find out on pages 260—261 What is virtual snowboarding? Find out on pages 264—265 A vaccine for ...
252 Inventions and discoveries Since people began living in simple dwellings, inventions have been a part of technological devel ...
INVENTIONS AND DISCOVERIES 253 TECHNOLOGY 2000 BCE 3000 BCE CANDLE Candlesticks dating from 3000 BCE have been found in Egypt a ...
254 The golden age of invention and discovery came in the last two hundred years. New scientific theories helped people invent t ...
INVENTIONS AND DISCOVERIES 255 TECHNOLOGY O German-born U.S. scientist Albert Einstein started his career studying new inventio ...
Modern medicine Medicine has come a long way since the Greek philosopher Hippocrates laid the foundations for modern medicine ne ...
WHO’S WHO? ■ Hippocrates (c. 460–c. 377 BCE) becomes the founding father of modern medicine. Hippocrates suggests that disease h ...
258 Electric cars Most cars use gasoline, made from oil, which causes pollution and adds to global warming. Oil supplies are run ...
ELECTRIC CARS 259 Microcab Useful for short journeys OTop speed 130 mph (210 km/h) ORange 250 miles (400 km) OMade in US T ...
«
8
9
10
11
12
13
14
15
16
17
»
Free download pdf
