Evolution: Myth or Reality

 People love to express their knowledge. From early days of human civilization, people are transferring their knowledge to other people which may be a new generation or fellow human living in different tribes or geographical locations. One topic that have been at the center of human curiosity and exploration of natural phenomenon is that how life was created on #earth. As the hypotheses and theories, trying to give an answer for the origin of life on earth, increased in numbers a special focus was given to evolution of various forms of life on earth. We see life in different forms. For example we can see life in plants, fish and other aquatic creatures and animals walking on earth. All animals are alike. We see animals of different sizes and body types. From ancient times, there has been two theories circulating in societies and still discussion in going on. First theory states that all living creatures were created in their present form.

Other theory states that current form of life has evolved from earlier simpler forms of life. This theory states that early form of life on earth was very simple. Early living organisms were simple unicellular organisms. Gradually these cells came together by evolutionary process and form multicellular simple organisms. This simple step took millions of years to be completed as evolution is very slow process. Due to its extremely slow pace people find it hard to believe in evolution as life span of human is not that long to observe considerable change in life forms. However in recent times, scientist were able to gather many facts to support their theories of evolution. DNA analysis has shown that all animals living on earth are have some DNA material common each other. For example birds, mammals and fish all have somewhat common DNA sequences indicating a strong relationship among ancestors of al these. However due to high complexity and invisibility of DNA this appears to be a counter intuitive for most people and desire to observe evolution with own eyes does not end. Thanks to hard work of biologists we have found live evolution evidence in living organisms. Peppered moth evolution is one example. During industrial revolution, peppered moth changed their skin color and dark skinned moths became normal. Presence of redundant organs in humans and other organisms also provides hints of evolution. Another very big evidence of evolution has been observed in modern human (#homosapiens) is disappearance of wisdom teeth in newly born babies. Yes yes you read it right. Do not get surprised. Wisdom tooth is disappearing fast in humans. New born babies do not have a place for growing wisdom tooth and it is expected that it will fully disappear in few years.

This disappearance is caused by no real use of teeth during life time of a human. Where this new discovery gives a strong evidence about evolution it also poses a question about evolutionary process. If a redundant organ gets disappeared why still we have appendix. Appendix is considered to be a redundant organ. It seems like despite the facts supporting evolution, this discussion of evolution does not appear to be ending in general public. As far as we are considered we supporters of evolution theory. Are u a supporter or you have another idea about this. Do share your opinion with us in comment section.

Share this article with your friends and see what do they have in their mind regarding evolution.

About author:

Author of this article is a science graduate.

Science: Saviour of mankind

 Earth has been house to life for millions of years. When we speak of life on earth, most exotic topic that comes to our minds is of Dinosaur reptiles. Many movies have been produced featuring different species of dinosaurs. It seems like this was the first form of life that appeared on earth but this is not true. Earth was house of life even before appearance of dinosaurs. After passing through millions of evolutionary years and processes earth witnessed the birth of mankind. With the arrival of human, a new era started on earth. At the start of human race, environmental conditions were very harsh. To cope up with these harsh conditions, human made use of greatest tool ever used or developed by all species on earth. Name of that tool is science. At the beginning there was little knowledge of different things happening around the humans. As the time passed more and more knowledge regarding the environment was accumulated that lead to series of inventions and discoveries. These inventions made things easier for humans. One such example is related to fire. When there was no concept of fire, humans faced many problems to keep themselves warm in cold weather. Once the process of igniting and maintaining fire was established, keeping warm inside a cave became much more easy. After discovering insulating capacity of different material, and use of these materials to cover bodies lead to even more comfortable winters. There is very long list of these discoveries that lead to modern day life style of humans on earth. We will discuss some of these discoveries in some other post. After so many discoveries and years of presence on earth human are still facing challenges to live on earth. One of the biggest challenges in modern area is food security. With continuous increase in population and reduction in agricultural land has created food crisis. In this grave challenge, again, science is helping us to overcome this problem. Though problem of food security has not been solved completely but there is tremendous increase in food production from same old agricultural land. New animal farming techniques are being developed in order to maximize meat and milk production in least possible time. Most recent attempt in this regard is lab grown meat. Though it seems very strange concept but scientists are working vigorously on this idea. If , one day, we are able to grow meat in lab, will you be the one who oppose such developments or will you promote such projects for protein shortage to come to an end. As for agricultural products are concerned multi layer farming is being introduced to increase production many folds. As these new methods give us hope to over come food crisis in future, there is still time to witness effectiveness of these methods. Only time will tell if science will again be saviour of man kind in this new challenge. 

What do you think  how will things go in near future? share your thoughts in comment section with us.

Flight on Mars

In 2021, it seems like world is under attack of Covid 19 (a virus commonly known as corona virus) and world is completely in chaos. While it seems very convincing but this is not all that is happening in 2021. Mankind has achieved a major milestone in space science. Mankind, who once dreamt of flying in air, was dreaming to fly in atmosphere of a planet other than earth for quite some time but it is 2021 when humans were able to make a flight (man less) in environment of Mars. On 25 April 2021, helicopter managed by NASA made a record of longest flight on mars. It flew 5 meter high and covered distance of 50 meter with speed 2 meter per second. NASA has attempted flights previously but this was the longest flight on Mars. This flight has given confidence to scientists for improved and better navigation across the planet. It has also helped the engineers and scientist to understand environmental conditions on Mars in much better way. This flight has taken mankind one step closer to the dream of visiting Mars one day. There have been talks of leaving earth and go and colonize Mars for ages. There were times when people had suggested to leave this dream and focus on other cosmological projects. But those have believed in this are finally getting something to cheer about. Ingenuity, name of helicopter, made his first flight on April 19,2021. This flight was 10 feet high. After making small distance Ingenuity returned and landed safely. Then it took its second flight and reached height of 16 meter same as high as for third flight. Then it made its last flight which was the longest and record breaking.

We will keep you updated about more progress on this project. In the mean time you share this article with your friends and tell them while you are sitting in room there are preparations being made for your trip to Mars. So be READY.

Carrier Diffusion in Semi Sonductors

 We know semiconductors have conductivity not as high as conductors and not as low as insulators. They have found a large number of application due to this unique behavior. We have categorized them into intrinsic and extrinsic semiconductors depending upon if they are in pure form or contain trivalent or pentavalent impurity. Those semiconductors with trivalent impurity are called as p type semi conductors and ones with pentavalent impurity are called as n type semi conductors. P type has holes in excess while n type has electrons in excess. We know diffusion is movement of particles due to concentration differences between two points. Particles move from high to low concentration. When n and p types are brought in contact electrons move from n side to p side due to concentration difference. Similarly holes move from p to n side due to concentration gradient. This happens due to thermal energy of electrons which exhibit itself in the form of kinetic energy of electrons. This diffusion leads to formation of depletion region in such materials.

For more understanding and short video explanation of charge carrier diffusion 

Click here for short video explanation.

What is Drag Force?

 When we were children, we always enjoyed pulling our hand out of window of car and experiencing air exerting force on our hand. We have also liked the scenes from action movies where heroes have their hair flying backward in air while running bikes at high speed. Some of us were amazed when they saw men jumping from air planes and coming down with the help of parachute. If you have ever swum in a pond of water, you would have known that moving through water takes a lot more energy compared to moving through air.

All examples cited above involve a special force called drag force. When an object moves through a medium, a retarding force acts on it. This retarding force is called drag force. Drag force depends upon different factors like speed of object, shape of object and nature of medium. Nature of medium is specified by viscosity. Viscosity is a resistive effect offered by medium due to resistance between various layers of medium. More viscous a medium is, greater will be drag force. A higher viscosity and hence greater drag force means greater force will be needed by the object to move through medium. As the velocity or speed of object is increased, drag force is also increased. In order to decrease the drag force and still be able to move at higher speed, objects are designed in special shapes. If we observe a ship and fish we can see similarity between two shapes. Both are narrow at the start and gradually increase in with. This is known as streamline body shape. Transporting vehicles on land, in air or water are designed while keeping this property in mind. This type of designs help in enhancing speed with greater stability and lower fuel consumption. For an object of spherical shape and speed v drag force is F=6πηrv. This relation is known as stoke's law.

In winter season, fog is a great example where we can observe drag force in action. Fog consists of tiny water droplets falling from high altitudes. As the fog droplets start falling down towards earth in air (medium of movement), air offers drag force to droplets. As the time passes, speed of fog droplet increases due to gravitational acceleration. As mentioned above, increase in speed increases drag force hence retarding force also act on fog droplet in addition to gravitational force. Hence speed of fog droplets depends upon net force and not only downward gravitational pull. For most droplets, weight i.e gravitational pull becomes equal to drag force. At this stage, net force becomes zero and hence droplets fall with constant velocity. Usually this velocity is very small and hence these droplets appear to be at rest. Due to this a large number of water droplets gather in air and we can see these droplets as fog. The constant velocity with which these droplets come down is known as terminal velocity. In coming posts we will discuss terminal velocity in detail.

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