Science in everyday life

1. The Science Behind Some Everyday Phenomena By Shehzil Zahid, Ayesha Nasir, Menahil Tahir , Sabahat Ali Khan and Hajra Amjad .

2. Volcanic Lightning by Shehzil Zahid German photographer Martin Rietze captured this eruption of the Sakurajima Volcano in southern Japan in February 2013.

3. In a thunderstorm, c louds are a collection of drips of moisture condensed around tiny particles floating in the air. These particles fly around and bump into each other. As this happens, the atoms bounce electrons off one another and build up electrical charges (ionization). When this build up reaches a certain level, the electrons start to reach out to the ground, looking to connect and equalize the charge separation of the negatively charged cloud and positively charged earth . These invisible paths of reaching electrons are called step leaders . Electrons on the ground are reaching out, too.* These send streamers of positive energy. Streamers come from anything on earth, including people. When the two opposite charges connect, the cloud discharges electrons into whichever streamer that meets the first step leader, creating lightning Positive energy flies up to the cloud from the earth to equalize the charge and the negative energy comes down. This happens repeatedly and quickly. The flash we see isn’t electricity, but an explosion of heat, because these moving electrons get extremely hot, causing the air around the bolt to explode.* What Causes Lightning?

4. First major study of volcanic lightning was in 1963, Iceland.* 50 years since, the most significant study was published in 2007*. The 2007 study corroborates what was found in the 1963 study – that volcanic lightning is also caused by the same charge separation that causes regular lightning. Scientists can only theorize what causes the charge separation. They assume large clouds and fast moving exploding rocks create a similar electrical charge to a thundercloud. The aerodynamics of positively charged rocks and magma flying into negatively charged clouds of ash and dust over and over again causes chaotic levels of rapidly evolving charge separation. The step leaders and streamers meet over and over again. Further studies in 2007 have led to the conclusion that there are at least two types of volcanic lightning – one that occurs at the mouth of an erupting volcano, and a second that dances around in the heights of the towering plume. Question of where the charges come from – unsure of whether it comes out of the volcano or if it is created just afterwards. The team from the 2007 study suggests that magma, rock and volcanic ash, jettisoned during an eruption, are themselves electrically charged by some previous, unknown process. Another holds that highly energized air and gas, upon colliding with cooler particles in the atmosphere, generate branched lightning high above the volcano's peak. Other hypotheses, still, implicate rising water and ice-coated ash par ticles. What Causes Volcanic Lightning?

5. MIRAGE By Ayesha Nasir

6. MIRAGE WHAT IT IS: “Mirage” is borrowed from the French language and its root word is “mirari” which is Latin for “to look”, “to wonder” A mirage is an optical phenomenon that occurs naturally When we see a mirage, we are actually seeing a reflection of the sky on the ground. THE SCIENCE BEHIND IT: Our brains are used to interpreting light coming to us in straight lines. This is not always the case: Light rays can experience refraction (they can be bent while passing through one medium to the other) Refraction occurs because light travels at different speeds through hot air and cold air. Temperature has an effect on air and its density. Cold air is denser than warm air, and therefore it has a higher refractive index. This means that light will be bent more as it passes through a medium with a higher index. The particles of light (also known as photons) bump into more matter in a more dense material which slows them down, and the ray of light therefore bends. As light passes from a LOW index to a HIGH index, the light bends towards the normal (a line perpendicular to the medium boundary). When light travels from a HIGH index to a LOW index, the light bends away from the normal. any observable event that results from the interaction of  light and  matter

7. WHAT HAPPENS: We now know that a mirage is created when light rays pass from colder air to the much hotter air near the ground. On a sunny day, the air directly above a road is warmer than the air above it. This is because the hot ground warms a layer of air just above the ground. A layer of very warm air near the ground refracts the light from the sky nearly into a U-shaped bend. Our brain thinks the light has travelled in a straight line. If the temperature change is significant enough, the light from the sky can be refracted by the hotter air before it hits the ground. Since our brain assumes that light follows a straight path, we follow the refracted light back to the source, which appears to be the ground. We think we have stumbled on an oasis when in reality we are seeing a shimmering image of the blue sky. 

8. Inferior mirages (such as the one I have explained) occur when there is strong heating at ground level. With superior mirages, colder temperatures can have a distinct (and almost opposite) effect which result in myths such as sailors seeing ships floating in the sky. With cold (dense) air near the surface and warm (less dense) air just above, an atmospheric lens is formed that can bend light This refraction results in making things look higher or taller than they actually are:  a superior mirage.  Occasionally, objects get reversed and distorted as well.

9. DEW DROPS By Menahil Tahir

10. DEW DROPS Water droplets Formation due to condensation Frost-dew in the form of ice Difference between Dew and Guttation Dew point Preferable weather conditions Dewfall and distillation

11. Drosometer – measuring instrument Dependence on radiation balance Range of Dew amount/ night – up to 0.8 mm Habitat for Fungus (Potato) Dew catching devices International Organization for Dew Utilization Indian Institute of Management Sciences- Large Scale Dew harvesting System

12. Walking By Sabahat Ali Khan

13. Walking Running With each step One foot at a times leaves contact with the ground. Both feet are off the ground. Also known as ambulation Means: ‘to roll’ Difference between running and walking: Walking Speed: depends upon the following factors; - height - weight - surface - culture - age - terrain - load - effort and fitness average speed: 5.0km/h average human child achieves independent walking ability at around 11 months old. Anatomy of walk: Complex not only feet have to move across the ground but hips, spine, arms, shoulders and head all move in sync to maintain balance in system.

14. Feet and Legs: -both propel the body forward. 1 2 3 1 -Starts with feet furthest apart. -Weight shifts to forward foot. 2 -Knee bends to absorb shock. -Recoil position. -Lowest point. 3 -Halfway through first step. -Foot passes supporting leg; passing position. -Character moves; knee straightens; lifts body; highest point. 4 -Character moves; weight bearing foot leaves off through heels; force transmitted to foot’s ball. -Body falls forward. -Free foot swings forward to catch ground. 4 5 5 -Half cycle completes. -Second half is exact mirror of first half.

15. Rainbows By Hajra Amjad Satti

16. Rainbow One of the most splendid color shows observed on the earth caused by the reflection and refraction of light in water droplets in earth’s atmosphere. Sun is always behind your face when you observe rainbow. Rainbows are not only formed after rain, but also on mist, spray, and airborne dew . The color band comprises of red, orange, yellow, green, blue, indigo, violet. Types of rainbow: Primary rainbow Secondary rainbow

17. TYPES OF RAINBOW Primary rainbow It is generated when white light makes ONE internal reflection in the drop. Colors are more clear. In this type red in on outer arc and violet on the inner arc. Secondary rainbow It is generated when sunlight makes TWO internal reflections in the drop instead of one. It is weaker/faint than primary rainbow because intensity of light reduced in the second refraction. Colors are reversed. Violet is on the outer arc and red in the inner arc.

18. Primary Rainbow

19. Secondary Rainbow

20. FINISHED