TECHNOLOGY RULES THE WORLD All kinds of technologies have been created to help people do work The first technologies were simple tools made by hand by one or two people Modern technologies often require thousands of people to make them Some are designed with and run by computers to perform tasks that would have been unimaginable just a few decades ago 4 Simple machines The earliest technologies were in the form of six tools we call simple machines These machines make work easier by changing the size or direction of a force such as a push or a pull They help a person do the same work with less effort 1 Wedge 2 Wheel and axle 3 Pulley Lever 4 6 Screw 5 Ramp
Ancient technology Many of the earliest technologies were developed to help farmers The Archimedes screw was invented 3,000 years ago by the Greek engineer Archimedes The screw raises water from a stream up the bank into fields to help crops grow As the screw is turned water is scooped up at the bottom and pushed up along the screw’s spiral through a tube to the field Farmers still use Archimedes screws today Digital revolution Modern technologies are driven by computers which are constantly being improved Computers do not only control machines they can also design them Human and machine Robotic arms and legs were designed for people who have lost limbs through illness or accidents A developing technology for robotic limbs allows them to be attached to nerves that lead to the brain The wearer can then control the limb with their thoughts Archimedes screw The present and the future Computer technology has created a new generation of machines that can learn from experience Self-driving cars have only recently been introduced on public roads With each journey self-driving cars learn from each new situation they face They can update their systems to show the best course of action to take if the same situation happens again In the future this technology could save many lives by reducing accidents 5 Google’s Waymo driverless car finds its way using a system called Lidarl It bounces laser beams off nearby objects to tell how close the car is to them Read on to discover the technological challenges inventors have overcome The answers to each project’s questions are found on page 31
CREATING A CURRENT A battery is a storage device for energy created from chemicals A battery produces an electric current when it is linked up to a circuit The first battery was made in 1800 by Italian inventor Alessandro Volta 6 Alessandro Volta Volta made his battery by building 1745 1827 up layers of zinc and copper separated by cloth soaked in saltwater When he connected the top and bottom of his battery with a wire an electric current flowed through it Named after its inventor the first battery was known as a voltaic pile Volta’s battery used cells of zinc copper and saltwater to create an electric charge Negative charge One cell Positive charge Saltwater Zinc Copper
How did it work Back then Volta did not fully understand how his battery worked Electricity is created by the flow of tiny particles called electrons In a battery a flow of electrons is created when the metals and chemicals contained in it react to one another A battery has one positive terminal or end and one negative terminal The electrons flow in one direction from the negative end of the battery through a circuit and back to the positive end of the battery In Volta’s battery a chemical reaction between the zinc and the saltwater produced a negative charge in the zinc plate Electrons entered the saltwater at the copper plate This set up a flow of electrons through a wire connecting the zinc plate to the copper plate Modern batteries follow the same basic principle as the voltaic pile Recharging A battery can be recharged or refilled with energy by reversing the chemical reaction in the battery Electrons will flow toward the negative terminal instead of the positive terminal restoring the battery’s power Some electric cars can travel more than 300 miles 482 km on one charge Their batteries can be plugged into on-street charging points or stations 7 project ICE CUBE TRAY BATTERY Power an LED with this homemade battery You will need an ice cube tray five galvanized zinc coated nails five pieces of copper wire distilled vinegar and an LED light-emitting diode 1 Wrap one piece of wire around the top of each nail so some wire hangs down the side 2 Fill the first six cells of the ice cube tray with vinegar Straddle the LED across the first two cells 3 Place a nail in one of the first two cells and have the copper wire dip into the next cell Place the next nail in that cell and drape the wire into the next cell Repeat until the last piece of copper dips into the cell with the LED The LED should light up If you have more nails and wire try using more of the cells to make a battery Does the LED shine brighter
