Science Pages

These Pages provide information about a single topic, or sometimes a group of related topics. They are intended to explain the ideas involved simply but also help you to understand how they fit into the real world.

Each Page is designed to be read through in order, as each Section builds on the Sections before, but for most longer Pages it is possible to go straight to a particular Section. On most Pages there are links to other Pages in my own Web Site or to other people’s Web Sites, but I suggest that you do not use them the first time you visit any Page on my Site, unless you need to do so in order to understand the Page, as you can easily lose the thread. You can always tell whether the Page you are looking at is one of mine or someone else’s because I do not think anyone else is writing on Ancient Egyptian papyrus.

There are some Maths Pages elsewhere on my web Site.

If you have not visited this Page before you might like to read the Note at the bottom of it to find out how and why it was made - to go to it please click here

To see what the navigation hieroglyphs mean please click here.

• Electronics
  About electronics, diodes and transistors, electronic gates and integrated circuits

• Mainly Physics
  
• Mainly Chemistry
  
• Mainly Biology
  
• Mainly Astronomy
  

Mainly Physics

• Bubbles
  About surface tension, soap films and bubbles
• Electronics
  About electronics, diodes and transistors, electronic gates and integrated circuits
  
  
• Electromagnetic Radiation
  An introduction to the different forms of emr, from radio waves to gamma waves
  
  
• Simple Series Circuits

  About potential difference and voltage, electrical current and resistance, and simple series circuits.

• Mains Electricity (under construction)
  
• Temperature scales
  A history of temperature scales and some information on the Celsius scale.
  
  
• Light and colour
  About light and colour, refraction, the separation of the colours in white light, spectrometers and spectral lines, colour temperature, the Doppler effect and red shift, and Sir Isaac Newton and the colours of the rainbow.
  
  
• Electrical Safety
  About fuses and circuit breakers, electric shock, earthing, static electricity, and lightning, lightning conductors, thunder and thunderbolts.
  
  
• The tides
  About the tides and how they are caused, their importance to life on Earth, and tidal energy.
  
  
• Levers
  About levers, class 1, class 2 and class 3, Archimedes and moving the Earth, ballistas, see-saws, nutcrackers and wheelbarrows, JCBs and our bodies.
  
  
• Density
  About density, mass and volume, the density of solids, liquids and gases, the effects of temperature and pressure on density, the Galilean Thermometer, and Archimedes and the King of Syracuse.
  
  
• Buoyancy
  About buoyancy, floating and sinking, buoys and life jackets
  
  
• Ships
  About ships and how they float, and the Plimsoll Line and other loadlines etc
  
  
• Stability of ships
  About the stability of ships, listing, rolling, capsizing and turning turtle etc
  
  
• Submarines
  About submarines and cartesian divers
  
  
• About buoyancy in air, balloons and airships
  A series of short articles about buoyancy in air, and hydrogen, helium and hot air and composite balloons and airships. Some of these pages are still under construction.
  
  
  • Balloons, buoyancy, hydrogen and helium
  • History of ballooning
  • Controlling a helium balloon
  • Hot air balloons
  • Composite balloons
  • Airships
  • Airships are safer than aeroplanes
  • The Airship in the 20th Century
  • The Airship in the 21st Century
  • Hydrogen, helium and safety
  
  
  
• The SI and its units of mass, length, area and volume
  An introduction to the SI and metric systems, and the Imperial and metric units for mass, length, area and volume
  
  
  
• Storage of gases
  About the different ways in which gases can be stored, and about natural gas, LNG and LPG, and the special properties of carbon dioxide and Dry Ice.
  
  
• Natural gas and coal gas
  About the history, distribution and storage of natural gas and coal gas
  
  
• The Three States of Water
  About water, ice, water vapour and steam, dew point, condensation, clouds etc
  
  
• A geological history of the Earth
  A brief description of some of the terms used by geologists, and the dates associated with some rocks and fossils
  
  
• Velocity and Acceleration
  About velocity and acceleration, the acceleration due to gravity and freely falling bodies, terminal velocity, inertial navigation systems and simple harmonic motion.
  
  
• Units of pressure
  About the units of pressure, pascals, torrs, bars and millibars, millimetres of mercury and centimetres of water, and other units commonly used.
  
  
• Units of time
  A simple guide to the different units of time in current use
  
  
• Nuclear Science
  
  
  • The nuclear structure of atoms
    About the structure of the nucleus of atoms, protons, neutrons and electrons, isotopes and mean relative atomic mass.
    
    
  • Radioactivity
    About radioactivity, alpha, beta and gamma radiation, radioactive decay, and natural radioactivity.
    
    
  • Radioactive decay and half-life
    About radioactive decay and half-life, with some worked examples
    
    
  • Ionizing radiation, health and safety
    
    
  • Carbon and other ways of dating
    About ways of dating things, including carbon, rubidium-strontium, potassium-argon and uranium-lead.
    
    
  • Uses of radioactivity
    
    
  • Nuclear fission
    
    
  

  Mainly Chemistry

  
  
  
  
  • Electrolysis About electrolysis and its uses
    
    
  • Atomic weight and the mole
    About Dalton’s Atomic Theory, the history of atomic weight, Avogadro’s Constant, the masses of the reactants in a chemical reaction, and the mole.
    
    
  • An introduction to Organic Chemistry
    About carbon, carbon chains and rings, organic and inorganic chemicals, the alkanes, alkenes and alkynes, homologous series, petroleum and petroleum gases, leaded and unleaded petrol, cracking, and polymerisation.
    
    
  • Atmospheric pollution
    A guide to acid rain, greenhouse gases and the ozone layer
    
    
  • Catalysis
    An introduction to catalysis and enzymes.
    
    
  • Calcium carbonate and the lime cycle
    About calcium carbonate, limestone, marble, chalk and calcite, their chemistry, lime and its uses, caves and stalagtites, and hard and soft water and water treatment.
    
    
  • Oxidation and reduction
    About oxidation and reduction, redox reactions and explosives
    
    
  • Atmospheric gases
    A list of the gases present in the air and a description of some of their properties.
    
    
  • The chemical elements
  • Metals and alloys
    A description of some common metals and their alloys
    
    
  • David and Goliath
    A story set in the early Iron Age in the Ancient Near East. It is here only because there are links to it from other Pages, for example on nuclear weapons proliferation and why, in terms of the reactivity series, the iron age came after the bronze age, and I could not think of anywhere else to put it. It won’t help you pass any exams but you might find it interesting!
    
    
  • Alcohol and alcohols
    A simple account of the alcohols, fermentation and alcoholic drinks
    
    
  

  Mainly Biology

  
  
  • The heart
    About the heart, one, two, three and four chambered hearts, valves, arteries and veins, pulse and blood pressure.
    
    
  • Respiration, breathing and photosynthesis
    About photosynthesis in plants, respiration in animals and plants, and breathing in animals.
    
    
  • Digestion, faeces and urea
    About the way in which we digest our food, what happens to substances we cannot digest, and the way in which we use proteins and get rid of our body's waste products.
    
    
  • Plant nutrition
    A simple account of nutrition in land and water plants, recycling organisms and the nitrogen cycle, and parasitic plants, mosses and lichens.
    
    
  • The carbon cycle
    A simple account of the carbon cycle on land and in water, and the role of plants, animals and decomposing organisms.
    
    
  • A simple theory of colour vision
    About how we see colour, rods and cones, and about how these make possible colour televisions and colour printing etc.
    
    
  • Warm and cold blooded animals
    About the difference between warm-blooded and cold-blooded animals and the meaning of some associated words.
    
    
  • Classification of animals
    A simple guide to the way animals are classified
    
  
  

  Mainly Astronomy

  
  

  In the following Pages the descriptions refer mainly to what is seen by people living between the Tropic of Cancer and the Arctic Circle. This is partly because this is where I live, and where most of my students and most of those who have told me they have visited my Web Site live (pace my Australian and New Zealand correspondents!), but mainly because although most of the greatest early astronomers and mathematicians came from China, India, Persia, Mesopotamia (an area which includes modern Iraq) or Arabia rather than Europe this is where they lived.

  Teachers of astronomy, at any level, might wish to know about, and perhaps even join, the Association for Astronomy Education, which exists to support and help them.

  • What can we see in the sky?
    An introduction to the sky, by day and by night, with links to other pages.
    
  • Why is the sky blue? and why we cannot see the stars by day
    
  • Eclipses
    About partial and full eclipses of the Sun and Moon, annular and hybrid eclipses, eclipse watching, eclipses and astrology, and transits of Mercury and Venus
    
    
  • The Earth, its orbit, and the length of the day
    About the orbit of the Earth, circular and elliptical orbits, aphelion and perihelion, sidereal, true solar and mean solar days, the Equation of Time and the solstices.
    
    
  • The Planets
  • The size of the Solar System
    A simple game for children to help them understand the size of the solar system
  • Shooting stars
    A simple account of meteors and meteorites etc.
    
  • Satellites and their orbits
    About natural and artificial satellites, and a discussion on the orbits of artificial satellites of the Earth.
    
    
  • Sam's Pages - a simple guide to naked eye astronomy
    Under construction - please e-mail me your comments and suggestions
    
    
    
  

  About these pages

  I was a science teacher for nearly twenty five years. These Pages are based upon the worksheets I produced during this time. Each Page covers one topic, and includes an explanation of the scientific principles involved and some background information. It also tries to place each topic into its historical, social, ethical and environmental context.

  I would greatly appreciate comments about them from anyone who has read them.

  
  There is also a long article on Time and its measurement elsewhere on this web site. It is not primarily for children but it might be of interest - to see it click here

  New pages are being added all the time so if the page you want is not here yet please come back next week, or e-mail me to tell me the subject that interests you.

  I also do private tutoring, in science and other subjects, to young people living in the Medway Towns - for more information about this please click here

  I also help children with their Ancient Egypt projects but I do this for nothing! Please go to Egypt for more information.

  Another Note - mainly for teachers

©Barry Gray May 2018