Understand our physical world
Hello how much beautiful is our physical world, you will learn here hidden concept of physical world .This is first chapter of class XI Physics, Study of Physical world is actually starting of Physics because you know study of nature is Physics.
So it is very important to understand physical world. A famous saying, perhaps you know “well began is half Done”. its meaning is if you start well that indicate 50% of your work is done.
So if you want to really learn Physics, You must first understand physical world.This is very interesting topic,You will really enjoy to learn this topic .
This is small topic but very important for concept point of view and basic understanding, In other words I can say. This is pillar of Physics, So lets start, what is in this beautiful physical world for you to learn ?
Physical World meaning world of Physics ( Physics Ki Duniya )
Very first i will Welcome you to Physics World.
Well i ensure you today you will get the key of Physics treasury, just open your eyes and brain to take it. How interesting is this and what you will learn here, I can simply say more than your expectation.
As I have already discussed in Physics definition it is branch of science now the question arises what is science ???
So first you should understand about “science” for this you have to go in ancient time. Do you know ? when the world was made in the ancient time, people started to see the natural phenomenon very closely and started to think over natural phenomenon like everyday sun set in the east every morning and sink in the west every evening.
Due to this natural phenomenon happening that time peoples concluded that the Sun is moving around the Earth. The person who was thinking like this was called Philosopher that time and this knowledge was called philosophy and those time different person were thinking about different things .
Peoples were freedom to think about their interest after this the knowledge became very vast and big. So it was really very difficult to study. Then people started classification of knowledge and this was the time when people made a boundary and divided in Science or Arts, Now this is coming from Ancient time to till date the boundary of science and arts. This boundary comes when you just pass 10th class.
you called to choose your interest Arts or Science for further study. now I will focus on difference between Arts and Science.Arts is a skill like develop speaking, develop drawing skill like this, but wait now I will discuss science.
In Ancient time Someone seen natural phenomenon happened then he observed that natural phenomenon through his eyes, And written down in note book and then experiment that natural phenomenon in the lab and given his thought and ideas and also made some rule and Laws.
After that another generation came study this rules and laws and think ahead of this carry out further enhancement written down his observation experiment and ideas. now third generation came and further carry out improvement in 2nd generation rules and laws. here what we see first generation made some rules and laws 2nd generation started from first generation left point third generation started 2nd generation left point wait 2nd generation will not start from initial zero point otherwise development will stop, and take long time actually, what we see here in the Science every phenomenon is observed, written, experiment give ideas made rules and Laws .what we see here this is in the organised manner. So “Science is Organised knowledge”.
Well which knowledge, I am talking here, don’t be confuse this is about “Nature” so Science is study about nature. you study how rain fall, sometime wind blow from east to west sometimes west to east, study about days and night this is all about Nature. so what is base of Science it is simple Nature. wait what is around us nature so in Science nothing is study outside nature this is key of Physics.
What is Organised knowledge ???
Whatever phenomenon happening in nature, we have made a scientific study method to observed if the phenomenon fit in scientific study method then it is ok otherwise it is just illusion. There are some point in scientific study method and very important to understand one by one each point is important.
Scientific method to study Nature.
Remember we always study nature in scientific method not a person otherwise it will be psychology.steps for scientific method
First we observed natural phenomenon around us like in rainy season water falls from sky to earth, sometime winter comes and sometime summer in a year, river water flows from west to east when we through a ball upward it come down to earth always not goes up all these phenomenon simply observed.
2 Controlled Experiment :
Here we copy the natural phenomenon in our lab in a controlled manner just we take example of rain we observed that before rain earth is heated then rain falls so same thing is repeat in lab first we heat water take a pot above the heated water we see some water molecules cloud on cold pot and made water drop just like rain.
take an another example of water flow in case of river we go in our lab take a tube we want water flow from left to right then we put left side high we see water is flowing from left to right we change our direction direction east, west, north, south in controlled manner but always water flows from left to right.you should know that knowledge comes from experiment and brain not from book. Science always start from Lab then it is written in book. take an example of ball through upward always come down to earth. Newton first observed this then experiment in Lab taking two heavy masses hang in the air seen that both masses come closer to each other then he told each mass body attracted each other then he written the laws in book Gravitation.
3 Reasoning (Qualitative/Quantitative) :
This is important point where we think logically the reason for natural phenomenon happening first qualitative means focus on characteristic take an example when we through ball it always come down this is it quality whether the ball mass is small or big it always come down. Newton after experiment was thinking why ball comes down towards earth of course there is something in the Earth and finally concluded earth having heavy mass due to this earth attract the ball then question arises that Sun and other planet having heavy masses .
why not sun attracted ball wait Sun also attract ball but due to sun large distance its force is very small compare to force of Earth everybody having masses attract each other Sun attract Earth due to which Earth rotate about Sun, Earth attract Moon due to which moon rotate around earth.now the question is why moon not fall on earth ? in universe every planet, star, galaxy attract each other and moving in universe. why moon rotate around earth because earth has more gravitation attraction on moon than other planet so it is bounded to earth similarly Sun has more affect on earth so earth rotate about sun.
Quantitative is change in parameter how output result change putting different parameter and analysis of output result how much changes happens.
4 Mathematical Modelling:
This is simply making of formula and should be correct for each condition apply lets an example we know Gravitational formula
F= Gm1*m2/R^2 if you want the upward through ball attracted by moon it is possible increase the distance from earth and near to moon simple moon will attract ball without fall down to the earth what we see here this formula is correct for earth and moon both gravitation phenomenon. take another example motion we will study in motion topic latter v = (u+at ) here v is final speed u is initial speed a is acceleration if a car is moving with acceleration and want final speed at an instant we can calculate easily with this formula so this is simply formula using mathematics tools. without this our scientific study incomplete. many scientist research rules and Laws but due to lack of mathematical modelling their research was not added in Laws and not publish. next generation given mathematical modelling and latter laws published. what we do with mathematical modelling.
using mathematical modelling we start prediction take an example we want to send an aircraft on moon then what will do just send it will reach no no wait here mathematical modelling will be use we know from gravitation moon will attract aircraft only it will be near to moon means earth gravity force will be less than moon where this point will be calculated F = Gm1*m2/R^2 it will give distance from earth now use formula v =u+at to calculate time when it will reach that distance now stop the aircraft engine moon will attract aircraft on its surface.what we are doing prediction on the basis of mathematical modelling.now our aircraft is going for mission on moon what next will happen wait and see.
there will be two condition either aircraft will land on moon or earth will pull down aircraft. if aircraft will reach on moon then our mathematical modelling is correct this fit for scientific study. if aircraft will pull down by earth then our mathematical modelling is not correct now we will have to correct is again till it become correct it happens with scientist after 50 times correction they reach at correct mathematical modelling.Newton was made a mathematical modelling for sound and calculated value for sound speed which give speed of sound 280 m/s which was incorrect actual value of sound is 320 m/s latter we will study it takes many years to make correct formula mathematical modelling but we just read in 5 minute we no need to expand year on it this is Science now 6 steps Scientific study is completed and it is important what is scientific study ??
So what so far we have seen Scientific study is totally different from illusion so it is called science any natural phenomenon pass in scientific study then it is ok otherwise we not accept it in science and it is illusion.
Important point for science Development
| Physical World
Science is dynamic nothing is final in science and it is good for human or mankind. anyone should not rigid on his rules and Laws it may be correct or may not be correct due to this rigidity in Ancient time world has lost a good scientist. In Ancient time human Church believes was that our Earth is great than other planet even Sun rotate about our Earth and was rigid on their faith that time a young scientist Galileo vision was very fast he told that no Earth rotate about Sun after his announcement stir among church people and was called him heretic and was finally Galileo was under house arrest until his death .
some time passes and latter on it was proved that Earth rotate around Sun but it was late world was lost good Scientist so nothing is final in Science we should welcome others new ideas now we have scientific method if it can proof through scientific method then accept it never rigid on your study and faith.
Above picture shown you the light nature what is light and how it travels from Sun to Earth very first Newton explained about light travels in straight line like arrow from Sun latter on Heisenberg experiment and told no light travels like water flows now which one is wrong both of them has done experiment and scientific study latter on it was proved that light has both nature no one is wrong.
Thanks for reading .