Why fire flies emits light?

Why fire flies emits light?

PROF WAQAR HUSSAIN

                   Fireflies appear to light up for a variety of reasons.

            First, the larvae of fire fly produce short glows. The adult Fireflies produce defensive steroids in their bodies that make them unpalatable to predators. So, the Larvae use their glows as warning displays to communicate their distastefulness.

             Second, many fireflies have flash patterns unique to their species and use them to identify other members of their species.

            Third, flash patter is used to discriminate between members of the opposite sex. Female fireflies prefer and love males having higher flash rates and high intensity of flash light.

Why fir flies produce flash of light?

 Why fir flies produce flash of light?

PROF WAQAR HUSSAIN

             The nitric oxide gas plays a critical role in firefly light flashing. Probably, when the firefly light is off, no nitric oxide is being produced so vessels providing oxygen are blocked. Nitric oxide is widely used in Viagra as it expands the blood vessels and increases the blood supply to the sex organ. Similarly it is used in heart attack as it widens the blood vessels and unblocks the constriction created by clot. Pomegranate is considered vital fruit for the patients and there is famous maxim in Urdu aik annar, so bemar (There is one pomegranate and the patients are hundred meaning the demand is too high and remedy is scarce.)

              The more proper reason of the flash of light of fire flies is:  When the firefly light is off, no nitric oxide is being produced. In this condition, oxygen entering the light organ is seized by the cell's energy-producing organelles “mitochondria” and thus oxygen is not available to light producing cells. In the presence of nitric oxide, which binds to the mitochondria, thus allows oxygen to flow into the light producing cells where it combines with the other chemicals needed to produce the bioluminescent reaction.  Nitric oxide breaks down quickly and till the new nitric oxide is produced, the oxygen molecules are again trapped by the mitochondria and are not available for the production of light. This supply and stoppage of nitric oxide is responsible for the flashing of fire flies light.

How firefly emits light?

How firefly emits light?

PROF WAQAR HUSSAIN

           Fire flies are winged beetles of insect family, comprising of 2000 species. Fire flies are also known as glow worm and light bug because they produce cold light of wavelength 510 to 670 nanometers. Light is produced due to a process called bioluminescence occurring in the cells of its lower abdomen with the help of a chemical luciferin(light bearer) which under goes enzyme catalyzed oxidation and an “intermediate” is formed in excited state that when returns to ground state, emits light. This light emitting process proceeds in two reactions:  

First, luciferin combines with adenosine triphosphate(ATP) to form luciferyl adenylate and pyrophosphate(PPi) in the presence of magnesium ions on the surface of enzyme luciferase.

              

(1) Luciferin + ATP  Luciferyl adenylate + PPi

Second, luciferyl adenylate combines with oxygen to form oxyluciferin and adenomonophosphate(AMP) and light is produced.

             (2) Luciferyl adenylate + O₂   Oxyluciferin +AMP+Light

   The light producing cells also have crystal of uric acid which reflects the light away from the abdomen. Fire flies have no lungs thus oxygen is supplied. through special tubes called trachea. The switching of light on and off is controlled by nerve cells or oxygen supply. 

Why Chameleons Change Colours?

Why Chameleons Change Colours?

PROF WAQAR HUSSAIN

               Chameleon are specialized clade of lizards that has 600 species, many has distinctive magical property of change of colour of their skin. Chameleons are famous for their quick color-changing abilities for three main reasons; first, to regulate their body temperatures; second, for social signaling and third, for camouflage.

             

 Heat regulation: Since chameleons can’t generate their own body heat so they change the color of their skin in a way to maintain optimum body temperature.  Chameleons in cold weather become dark to absorb more heat, whereas in hotter times, turn into lighter grey colour to reflect most of the sun’s heat.

             

Social Signaling: Chameleons’ changes colour to communicate their feeling. Males become bright to signal their dominance and turn dark in aggressive mood.  Males show lighter, multicoloured patterns when courting females.

Females can let males know if they are willing to mate by changing the color of their skin.

              Camouflage: Some species adjust their colors for camouflage in accordance with the vision of the specific predator species (bird or snake) by which they are being threatened.

                Chameleons are domesticated so Owners should know their colour language to get to their inner feeling.

 How chameleon changes their colours?

             The outermost layer of the chameleon’s skin is transparent. Beneath this are three 

more layers of skins which contain specialized cells called chromatophores. The chromatophores at each layer are filled with sacs of different kinds of pigment.

         Chromatophore cells in the first and upper layer are called xanthophores(yellow pigment) and erythrophores(red pigment).

         Chromatophores cells in second and middle layer are called iridophores or guanophores; these contain guanine appearing blue or white.

       Chromatophores cells in the third and the deepest layer called melanophores; contain melanin, the dark brown pigment.

           These pigments are packed in tiny sacs within the cells.  When a chameleon experiences changes in body temperature or mood, its nervous system tells specific chromatophores to expand or contract.

For instance, an excited chameleon might turn red by fully expanding all his erythrophores, blocking out the other colors beneath them

         With these layers of cells, some chameleons are capable of producing a dazzling array of reds, orange, pinks, yellows, blues, greens, purple, black and browns. These bold statements won’t help them blend into the background, but they will allow them to get their message across to other chameleons loud and clear.

Why plants leaves are green?

Why plants leaves are green?

PROF WAQAR HUSSAIN

        

          The colour of plant leaves is green due to the presence of chlorophyll in their chroloplasts. Chlorophyll is responsible for the photosynthesis and helps plant to utilize water of the ground, the carbon dioxide of atmosphere and the sunlight of the space to bind H₂O and CO₂ molecules to synthesis glucose and oxygen.So chlorophyll is the factory of plant which provides food for plants and oxygen for the animals.

      Chloro means green. It is an organo-mentallic complex of porphyrins esterified with long chain alcohol of phytol. Magnesium atom is present in the centre of chlorophyll. It effectively absorb blue and red light.
    The chlorophyll is green because it absorbs red and blue colour wavelengths and green is not absorbed thus it is reflected back and reach the eyes and plant looks green.

          

         With the approach of autumn, plants produce less chlorophyll because light regulates the production of chlorophyll.As a result, the green colour fade. The other pigment that affect the leaf colour are anthocyanin which makes the leaf red; caroteniods stain the leaf red, yellow or orange.

Why a person becomes pale after malaria?

Why a person becomes pale after malaria?

PROF WAQAR HUSSAIN

          It is a febrile disease caused by a parasite plasmodium transmitted by mosquito of genus Anopheles. The parasite, thus injected, attacks the red blood corpuscles and complete its life cycle there and its young ones rapture away the red blood cell, and comes out to the blood stream and shivering, fever and other symptom initiate. So, in malaria, RBC is destroyed and due to scarcity of red blood corpuscles, the patient looks pale.

Why the blood is red?

Why the blood is red?

PROF WAQAR HUSSAIN

          

 Human body contains about 5.5 dm³ (liter) blood which is red as it contains cells which are red. Why these cells are red? They are red due to protein haemoglobin which is transition metal complex containing iron ion (II or III) in the centre. Haemoglobin upload oxygen from the lungs and passes through 60,000 miles network of blood vessels and capillaries and ultimately reaches the door of 6 trillion cells,

knocks the door and delivers oxygen to every cell that is used by the cell to oxidize glucose to H₂O and CO₂ and Energy. Cell makes use of this energy for its survival and other functions. On return, haemoglobin carries CO₂ and transports it to lung and shows it the way out.

             Iron ion in the core of hemoglobin has the property of reflecting red light and there is so much iron in our blood, which make the blood to appear red. When hemoglobin is carrying a lot of oxygen (oxygenated blood), the colour of blood is bright red. When most of the oxygen has been released to the body, blood (deoxygenated blood) becomes dark red. It is contrary to 

popular belief that deoxygenated blood is blue. In fact, veins under light coloured skin only look blue because the skin changes the optical properties of the light that passes through the skin. 

A VISUAL MODEL OF OXYGEN BINDING PROCESS

Why the foam of sea is white?

Why the foam of sea is white?

PROF WAQAR HUSSAIN

          Sea foam is produced by the constant agitation of the sea water especially when it contains high amount of dissolved organic compound which acts as surfactant or foaming agent. When sea water is churned foaming agent, at top layer of sea, entraps air as bubble. When the current of sea-water flows, this foam is dragged the sea shore.

          Foam is made up of so many little bubbles, each acting as a prism, and refracting the sun’s rays into their primary colours. As there are so many prisms, the various rays are so interlaced and interwoven as to produce white light.

Why different animals have different coloured skin covering?

Why different animals have different coloured skin covering?

PROF WAQAR HUSSAIN

        

         There are many reasons why different animals have different colour of their skin. 

              Hiding is one of the main reasons. The wild animals have colour, pattern, shape, etc. matching to the natural environments in which they live. Those living in grass are green while those dwelling in holes or the earth are brown coloured. Thus, they cannot be easily detected. The black and white stripes of zebra blend together and their proportion exactly matches the pale tints produced by moonlight in arid land. The colouring of the lion exactly matches the sandy grass-lands in which it roams. Cryptic colouring is very useful to animals in their struggle for existence.

       

 Sometimes the colouring of the animals is aided by special modifications of shape, etc. The animal is mistaken for some well known object. This is what happens in the case of insects which resemble pieces of straw, or in case of butterflies which fold their wings so as to look exactly like dry leaves.

      The colouring is utilized offensive purposes. When animals approaches to attack other animal, their skin colouring akin to surrounding help them and their victim cannot recognize them easily and thus their intention remains unnoticed and help to achieve success.

        

Another type of protective colouring is mimicry. In this case the animal resembles some other animal which is specially disliked by its enemy. So skin colouring is used by animals for both defensive and offensive purpose. The nature has bestowed this covering for their survival apart from their identity and beauty.

Watch the most spectacular natural coloured storm?

Watch the most spectacular natural coloured storm?

PROF WAQAR HUSSAIN

(AMAZING VIDEO IS PLACED AT THE END....MUST WATCH)

             If you want to see the most spectacular phenomenon of coloured storm of aurora then travel and reach near the arctic or antartic region.Aurora is a luminous meteoric phenomenon of electrical character seen in sky above  Polar Regions with a tremulous motion and giving forth eight streams of rays. Aurora or curly coloured dashing storm of light. This illumination of sky flowing from North Pole is called Aurora Borealis or Northern Lights, and streaming from South Pole is called Aurora Australis or 

Southern Lights. 

            Northern lights or southern lights are caused by collisions of fast moving electrons, coming from sun, with oxygen, nitrogen present in our atmosphere. 

              These solar electrons of solar wind collide with electrons of oxygen and 

nitrogen molecule. As a result, electrons of oxygen and nitrogen are excited i.e. they shift to high energy state When excited electrons return to normal ground state, energy is released in the form of radiation of different colour and form aurora. Or simply, lights pour out when excited oxygen and nitrogen return to ground state.the principle of aurora is akin to reason of firework where different salt are heated and electrons jump to higher energy state and when they return to their ground state, light of different colours is emitted.So, one can say that aurora are nature's firework.Aurora have different form but the most important one is curtain like arc which breaks into eight arms.The complete ring can be seen only from space.This ring is called auroral oval.Aurora has different colours; RED is due to Oxygen at high altitude;GREEN is due to oxygen at low altitude; BLUE is due to nitrogen; YELLOW is due to mixing of red and green and PINK is due to mixing of light green and red. Different auroral shape can be seen in single night. The sound produced by aurora are faint clapping, crackling sounds, it seems that nature is celebrating joy with natural fireworks and clapping.Keep in mind, when nature becomes it manifest his pleasure with colours and sounds.Butterflies speak with colours; flowers manifest joy with colour and fragrance; raindrops celebrate by making curved colour band of rainbow, cuckoo utters melodious song; firefly show his ecstasy with cold soothing light; many other examples.But the lightening and colour and sound of aurora have no match.
            Look at the Union Jack, flag of UK; there are eight arms of red and white colour with background colour of blue.It is the symbol of aurora, eight red and white arms represent aurora rays and blue background represents sky.I think who ever was designing  Union Jack must had aurora in his subconscious. There are number of structures and building representing aurora pattern.for example, Faisalabad is the third largest city of Pakistan, it old name was Lyallpure named after Sir James Lyll, Lt Govenor of the Punjab.This city has a famous Hour Tower(ghanta ghar) built by British in 1903 situated in the centre of eight markets that look like the Union Jack from aerial view and represents  the aurora.

           The most appropriate place to watch aurora is Alaska, Canada and Scandinavian countries.The resident of USA can see this curly coloured storm near Canadian border.If you are lucky then you can even watch aurora in Japan.

NOW WATCH THIS AMAZING VIDEO....FOR FURTHER DETAIL OF PHENOMENON, READ:- http://profwaqarhussain.blogspot.com/2014/10/why-auroras-emit-8-streams-of-coloured.html    

Why Auroras emit 8 streams of coloured light?

Why Auroras emit 8 streams of coloured light?

PROF WAQAR HUSSAIN

             

     Aurora has literal meaning “sunrise”; Aurora is also name of Roman goddess of dawn. Aurora in Urdu is called Kutub raushani(light of poles).It is a luminous meteoric phenomenon of electrical character seen about 80 km above  Polar Regions with a tremulous motion and giving forth streams of eight Aurora or curly coloured dashing storm of light. This illumination of sky flowing from North Pole is called Aurora Borealis(Boreas means north wind) or Northern Lights, and streaming from South Pole is called Aurora Australis or

Southern Lights. They are actually caused by radiation from the sun-spots. A stream of electrons thrown out from the solar cyclone reaches the atmosphere of the earth and there strike the gases in the upper atmosphere, it causes them to vibrate, excite, glow and flow.

            Northern lights are caused by collisions of fast moving electrons (coming from space) with oxygen, nitrogen and other gas molecules present 

in our atmosphere. These electrons originate from the sun. The outermost surface of sun corona has temperature of 2 million ^oC and emits solar wind containing free electrons and positive ions. Solar wind reaches earth with speed of 400km/s and magnetic field of 2-5 nanoteslas. This speed and magnetic field increases several times during magnetic 

storm. Earth magnetosphere is formed by the impact of solar wind on earth magnetic field which blocks solar wind. Still some potion travel toward the poles.

               Electrons of solar wind collide with electrons of oxygen and nitrogen molecule. As a result, electrons of oxygen and nitrogen are excited i.e. they shift to high energy state or oxygen and nitrogen lose their own electrons to form ions. 

When excited electrons return to normal ground state, energy is released in the form of radiation of different colour and form aurora. Oxygen generally gives greenish –yellow or red light while nitrogen gives off blue light.

Why diamond glitters and gives white as well as coloured light?

Why diamond glitters and gives white as well as coloured light?

PROF WAQAR HUSSAIN

           

Diamond literal meaning unbreakable is an allotropic form of carbon with face-centered cubic structure called diamond lattice. It is the hardest known natural material with high optical dispersion (ability to disperse light of different colour), high refractive index (2.417), etc.

       

          Diamonds glitter due to total internal refraction (explanation is given below as 1) It is cut in a way to get number of faces so that if a ray of light enters in it, it must strike the face at an angle greater than its critical angle (for diamond it is approximately 24.4^o degree).When light strike a surface at angle greater then critical angle, it is reflected back instead of going out as refraction. Greater are the reflections, greater is the glitter. The brilliance also depends on the cutting pattern of a diamond .Greater are reflective surfaces, greater are reflections and in turn greater is glitter. So, its brilliance also depends on the diamond cutter's skill. It is the art of the lapidary, cutting numerous facets which enable the material to make the most of its reflective powers.

                  

         Or have another dimension of the above discussion. Diamonds have a high refractive index (explanation is given below as 2) which means that light travelling through them will be bent more than in any other substances. Bending of light is due to fact that the speed of light is slowed down in a diamond. When it hits the face, when the speed is drastically reduced, it tends to bend significantly. So, light instead of going out, it is reflected back and again it strike other face and is reflected and it strikes many times and meet the same fate. Finally it finds the way out either as white light or as band of seven colour. It is analogous to carrom board striker which when struck with full force; keep on striking different sides of carrom board. This entire phenomenon appears to observer as glitter. It is called an adamantine luster.

1) Total internal reflection. When, a beam of light passes from a denser to a rare medium, refracted ray bends away from the normal and the angle of refraction is greater than the corresponding angle of incidence. As the angle of incidence increases, the angle of refraction also increases till for a certain value of angle of incidence, the corresponding angle of refraction equal to 90⁰ .The angle of incidence for which the angle of refraction is 90⁰ is called the critical angle.

           When the value of angle of incidence becomes greater than the critical angle, the ray of light no longer suffers refraction but the whole of it, is reflected back in the denser medium. Such a reflection of light is called total internal reflection.

           Let’s have an analogous example, striker in carrom board shows total internal reflection.

2) Refractive index, also called index of refraction, measure of the bending of a ray of light when passing from one medium into another. If i is the angle of incidence of a ray in vacuum (angle between the incoming ray and the perpendicular to the surface of a medium, called the normal;  and r is the angle of refraction (angle between the ray in the medium and the normal), the refractive index n is defined as the ratio of the sine of the angle of incidence to the sine of the angle of refraction; i.e., n = sin i / sin r. Refractive index is also equal to the velocity c of light of a given  wavelength in empty space divided by its velocity v in a substance, or n = c/v.( Encyclopedia Britannica)

          It is the measure of degree of speed of lessened in a material relative to speed of light in vacuum. Its high value indicates that the said material has reduced the speed of light to a greater extent.