Technology

7th grade

What is Technology?

• It’s the invention of tools,instruments or information using scientific knowledge and technical procedure for practical purposes making life conditions easier and better.Having new knowledge leads to creation and discovery of new things.

Paleolithic and Neolithic age

• OLD STONE AGE –Paleolithic age• During this age man is nomad.He keeps moving

from one place to another looking for food.Fire is discovered .Many tools for hunting and fishing are invented.

• New Stone Age –Neolithic age• Metals are discovered which provides man with

better tools for working the land and hunting. This makes him become sedentary . Animals and plants are domesticated.

FIRE

• The technological potential of fire is not discovered well until the Neolithic period.

• Bricks were invented around 8000 b.C. First they were just laid on the floor to be baked in the sun.

• Pottery, is known from about 6500 b.C. • The melting and casting of metal require

considerably higher temperatures and are not attempted until about 4000 BC.

Inventions

• Writing • It divides prehistory and History;it created History.The

Summerians invented it in 3500 a.C • The earliest known evidence of a loom comes from

Egypt in about 4400 BC• The wheel is often quoted as the single most important

advance in early technology around 3000 BC.• An important adaptation of the wheel in technology is

the pulley - a wheel with a rope that exerts force on an object at the other end - 1500 B.C.

Millstones: 2nd century BC

• The milling of grain into flour, previously done by hand on a rough flat stone, achieves technological advance with the introduction of heavy stones which grind against each other to crush the seeds between them.

• 200 b.C Pompeii

Renewable energy

Renewable energy

• Is energy that comes from RESOURCES which are naturally replaced on a human timescale, such as sunlight,wind,rain, tides,waves,biomass and geothermal heat.

• Renewable energy replaces conventional fuels in these areas:

• electricity,• air and water heating/cooling• motor fuels

Fossil fuels vrs Renewable resources• Gasoline,coal,natural gas and diesel come from fossil

fuels and are not renewable. They take millions of years to be made, and cannot be renewed in our lifetime (they are called fossil fuels because they are as old as fossils).

Problems with fossil fuels:• cost• Pollution• global gases warming• Becoming hard to find Renewable resources are usually much cleaner. But they

can also cost more. New technology for renewable resources is helping to make them cheaper

Types of renewable energy

• Aeolian energy- wind energy• Solar energy- sun energy• Wave energy-ocean energy• Biomass- from plants and animals• Geothermal energy- underground heat• Hydroelectric energy- water