education infogram

Quantum cryptography uses physics to generate a key that realises on the properties of light, in particular, photons. A photon is a tiny particle of light that is too small to be seen individually. All light is made up of photons; not only visible light, but also radio waves, television broadcast, x-rays, ultraviolet and so on. The difference between all of these applications is the wavelength of the radiation involved.         Photons have no mass and travel at the speed of light. They have another property known as polarisation which, through quantum mechanics enables a secret key to be sent from the sender to the receiver. This key can then be used to decrypt an encoded message sent over a public channel such as the internet. The particular quantum properties of photons mean that if an eavesdropper looks at the secret key, a change occurs to the particles of light being observed. The receiver would then know that something had changed and that their communica...

Robots are able to copy the movements and actions human beings when they perform certain tasks, but to become more useful to us, robots are now being taught to think for themselves and to react to situations as human would. Work is being carried out so that robots, using artificial intelligence, can think analytically.     Robots can be categorised into two different types: fixed and mobile. Some are fixed to single point in the factory and the work that needs to be done is brought to them. This type of robot is usually called a robot arm because, like our arm, it is fixed at one end and yet has a large degree of movement available. Robots are used in production lines because they: produce more consistent results than human workers  are more precise than a human being can work continuously without a break do not require heat or light do not need to be paid, altho they do cost a lot to buy in the first place can work in areas or with materials that would be d...

There are three main kinds of blood vessels: arteries,   capillaries  and  veins [you can see in the figure above]. Arteries carry blood away from the heart. They divide again and again, and eventually from very tiny vessels called capillaries. The capillaries gradually join up with one another to form large vessels called veins. Veins carry blood towards the heart. Arteries When blood flows out of the heart, it enters the arteries. The blood is then at very high blood pressure, because it has been forced out of the heart by the contraction of the muscular ventricles. Arteries therefore need very strong walls to withstand the high pressure of the blood flowing through them.         The blood does not flow smoothly through the arteries. It pulses through, as the ventricles contract and relax. The arteries have elastic tissue in their walls which can stretch and recoil with the force of the blood. This helps to make the flow of the blood smoother....

The blood circulation The heart has four chambers called right atrium, left atrium, right atrium and left ventricle. In the heart there are four valves called pulmonic valve, aortic valve, mitral valve, tricuspid valve.  The functions starts when blood is carried from the lungs to the left atrium by means of the pulmonary vein the left atrium relaxes this blood is pumped to the heart when the left atrium contracts the left ventricle relaxes simultaneously, the left atrium pushes the blood into the left ventricle through the one way valve, when the left ventricle contracts the blood is pumped to the  aorta, which carries oxygenated blood in different parts of the body except the lungs, The oxygenated blood reaches tp the different parts of the body through the vessels called  arteries , the arteries get branch into the  capillaries,  which then reaches to the different organs in the body, the blood then become deoxygenated, the blood capillaries then i...

a. b. The circulatory system shown in figure b.  is a double circulatory   system . This means that the blood passes through the heart twice on one complete circuit of the body. We can think of the circulatory system being made up of two parts - the blood vessels that take the blood to the lungs and back, called pulmonary system, and the blood vessels that take the blood vessels that take the blood to the rest of the body and back, called the systemic system.               Double circulatory system are found in all mammals, and also in birds and reptiles. However, fish have a circulatory system in which the blood passes through the heart only once on a complete circuit. This is called a single circulatory system, and is shown in figure a.               Double circulatory systems have some advantages over single circulatory systems. When blood flows through the tiny blood vessels in a fish's gills...

Sounds are vibrations that travel through the air [or another material], produced by vibrating objects. How can we picture the movement of the molecules of the air as a sound travels through? Figure above shows how the vibrations of a turning fork are transmitted through the air. As the prong of the fork moves to the right, it pushes on the air molecules on that side, squashing them together. These molecules push on their neighbours, which become compressed, and which in turn push on their neighbours, and so on.         It is important to note that the individual air molecules do not travel outwards from the vibrating fork. The air molecules are merely pushed back and forth. It is the vibrations that travel through the air to our ears.         This picture of how a sound travels also explains why sound cannot travel through a vacuum.  There are no molecules or other particles in a vacuum to vibrate back and forth.      ...

Most of the energy we use can be traced back to the Sun: Fossil fuels are stores of energy that came from the Sun millions years ago. Radiation [light and heat] from the Sun can be absorbed by solar panels to provide hot water. Sunlight can also be absorbed arrays of solar cells [photocells] to generate electricity. In some countries, you may see these on the roofs of houses.  The wind is caused when air is heated by the Sun. Warm air rises; cool air flows into replace it. This moving air can be used to generate electricity using wind turbines. Most hydroelectric power come ultimately from the Sun. The Sun's rays cause water to evaporate from the oceans and land surface. This water vapour in the atmosphere eventually forms clouds at high altitudes. Rain falls on high ground, and can then be trapped behind a dam. This is the familiar water   cycle.  Without energy from the Sun, there would be no water cycle and much less hydroelectric power.      ...

As well as lightning flashes, we experience static electricity in a number of ways in everyday life. You may have noticed tiny sparks when taking off clothes made of synthetic fibres. You may have felt a small shock when getting out of a car. An  electrostatic charge  builds up on the car and then discharge through you when you touch the metal door. You have probably rubbed a ballon on your clothes or hair and seen how it will stick to a wall or ceiling.         If you rub a plastic ruler with a cloth, both are likely to become electrically charged. You can tell that this is so say holding the ruler and then the cloth close to your hair - they attract the hair. [ If your hair is not attracted, try some tiny scraps of paper instead.] You have observed a static electricity generated by rubbing. You have also observed that a charged object may attract uncharged objects.     a. b.         Now we have to think systematically...

  a. liquid-crystal thermometer b. liquid in glass thermometer With both of the thermometers shown in figure, it is important to wait for a minute or two if you want to see the correct reading. This is because the thermometer has probably been stored somewhere relatively cool, perhaps in a drawer at 20 degree celsius. The patient's temperature will be approximately 37 degree celsius, and it takes a short while for the thermometer to reach this  temperature.       This gives us idea of what we mean by temperature. The thermometer is placed in contact with the patient's body. It has to warmup until it reaches the same temperature as the patient. Energy from the patient is shared with the thermometer until they are at the same temperature. Then you will get the correct reading. [So the thermometer does not tell you the patient's temperature - it tells its own temperature! However, we know that the patient's temperature is the same as the thermomete...

                         A motor is a device for transforming electrical energy into mechanical [kinetic] energy. To generate electricity, we need a device that will do the opposite: it must transforms mechanical energy into electrical energy. Fortunately, we can simply use an electric motor in reverse. If you connect up an electric motor  to a meter and spin its axle, the meter will show that you have generated a voltage.     Inside the motor, the coil is spinning around in the magnetic field provided by the  permanent  magnets. The result is that a current flows in the coil, and this is shown by the meter. We say that the current has been included, and the motor is acting as a generator.              There are many different designs of generator, just as there are many different designs of electric motor. Some generate direct current, others genera...

                                           The underlying principle for the formation of these colours is shown above in picture. When white light passes through glass [here a prism], it refracts as it enter and leaves the glass, and split into a spectrum of colours. You should notice that the colours merge into one another, and they are not all of equal widths in the spectrum. A rainbow is just a naturally occurring spectrum. White light from the sun is split into a spectrum of colours as it enters and leaves droplets of water in air. It is also reflected back to the viewer by total internal reflection, which is why you must have the Sun behind you to observe a rainbow.        The splitting up of white light into a spectrum is known as dispersion  ['spreading out']. IsaacNewton set out to explain how it happens. It had been suggested that light i...

Osmosis and animal cell : The figure illustrates an animal cell in pure water. The cytoplasm inside the cell is a fairly concentrated solution. The protein and many other substances dissolved in it are too large to get through the cell membrane. Water molecules, though, can get through.     If you compare this situation with the figure osmosis, you will see that they are similar. The dilute solution in figure osmosis and the pure water in figure animal cell in pure water are each separated from the a concentrated solution by a permeable membrane is the cell membrane. Therefore, osmosis will occur.       Water molecule will diffuse from the dilute solution into the concentrated solution. What happens to the cell? As more and more water enters the cell, it swells. The cell membrane has to stretch as the cell gets bigger, until eventually the strain is too much, and the cell bursts.        An animal cell in a concentrated solution. I...

DIRECT CONTACT  :                                       The   passing of a pathogens to an uninfected person is called transmission. The entry of the pathogens into body is known as infection. The person[or animal] in which the pathogen lives and breeds is to be a host for that pathogen. Some pathogen pass from one person to another where there is direct contact between an infected person and uninfected one. INDIRECT CONTACT  :  Most pathogens ar transmitted indirectly. Indirect methods of transmission include the following: Through the respiratory passageway cold and influenza viruses are carried in the air in tiny droplets of moisture. Every time someone with these illnesses speaks, coughs or sneezes, millions of viruses are propelled into the air. If you breathe in the droplets, you may become infected. In food or water bacteria such as...

                              A pathogen is a microorganism [a tiny organism that can be seen only with microscope] that a      cause diseases. Many diseases are caused by pathogens that get into our bodies and breed there. There are four kinds of microorganism that can act as pathogens, and some of diseases the they cause.                1. Viruses - influenza, common cold, poliomyelitis, AIDS.              2. Bacteria - cholera, syphilis, whooping cough, tuberculosis, tetanus.            3. Protoctists - malaria, amoebic dysentery.            4. Fungi - athlete's foot, ringworm. Diseases that are caused by pathogens can usually be passed from one person to another. They are called transmissible diseases. There are several types in which pathogens ...

                                     1. MASTERY by George Leonard                                      2. BIG MAGIC  by Elisabeth Gilbert                                                 3. ATOMIC HABITS by James Clear                                                   4.  THE SECRET TO SUCCESS by Eric Thomas                                        5. THE WAR OF ART by...

The environment (surrounding) of a living organismis always changing. Think about your own environment. The temperature of the air around you changes. For example,if you live in a temperate country, it might be -10 degree Celsius outside on a cold day in winter, and 23 degree Celsius indoors. If you live in a tropics, the outside temperature may be well over 40 degree Celsius.        The cells inside your body, however, do not have a changing environment inside you almost the same, all the time. In the tissue fluid surrounding your cells, the temperature and amount of water are kept almost constant. So is the concentration of glucose. Keeping this environment constant is called  homeostasis.                   Homeostasis is very important. It helps your cells to work as efficiently as possible. Keeping a constant temperature of around 37 degree Celsius helps helps enzymes to work at the optimum rate. Keepi...