A study on Entropy - 4

I have already told that the efficiency of an ideal engine is [ 1-T'/T ] and no other engine (all other engines are real ones) have more efficiency than this one.

One of my fellow readers have asked a silly doubt,"this is all about engines right?" Yes,but an engine means a thermo dynamical observational system. This phrase doesn't digest for common people that's why I used 'engine',and it not only represent an engine of a machine or an automobile but every heat taking - giving systems.

So,there can't be more efficient engine than a ideal one. (if you have confusion about ideal and real one, think like this. Legends are ideal characters,but in real life we can't find any,as every people are real ones. There isn't any ideal legends,everyone should have any singles flaws or defects),as per the equation, the maximum value for efficiency is 1 and minimum is ofcourse 0. (how did this come? ,see the image)

What if then, the temperature becomes negative? (see the image), the efficiency is greater than 1. We just said, 1 is the maximum value and that is too ideal... How can any system ever get more efficient than 1? How can one be more legendious than legend? How can you be more yourself than yourself? How can water be more watery?

So the concept contradicts reality,hence the assumed thing is not real or generally,the negative temperature in kelvin scale is impossible.

This doesn't mean negative temperatures are impossible,after all its just temperature and positiveness and negtiveness are what we attributed to them. And this is only valid in kelvin scale ,not in Celsius or Fahrenheit scale. Kelvin is the general scale,so that's how it become more important.

But what if,there is a particular case in which negative kelvin exists?

A study on Entropy - 3

In my previous post a stated that the entropy is being increased. Not just of a engine's,but that of entire universe's.

But why do I have to care?  Does it affects me? Absolutely no!!!!
But yes!

Entropy is the measure of disorderness or it is the cause for heat exchange. We can also tell an increment in entropy will also suggests,somewhere in the universe some heat is being transferred from a high temperature to lower one. Well,heat can only go like that unless some special works (refrigeration) are done.

But still what does it costs?
It costs nothing,but engulfs everything. Universe is expanding,making more and more space for heat to spread. And Entropy which is always increasing and increasing, reduces the total amount of higher temperature region itself. At a certain point of time (after millions of billions of earth years) universe will ask for almost every energy source for this entropy to go on increasing along with expanding universe. It is thought to be a fate of our universe,we don't know yet.

All the available energy will be used up. Which is stored as potentials,mass,heat,data's,information etc
The loss of available energy is equivalent to gain in entropy.
As #entropy is gaining , available energy reduces which in turn makes #universe a desert where everything is unique as sand,except there won't be anything to watch it.

At the maximal #entropy state all the physical variables,the temperature,pressure,composition...all will be uniquely distributed. And it will be impossible to differentiate between two points in the universe.

Scientists refers this to as Heat Death of the #Universe

The temperature at this stage will be zero kelvin (or -273 Celsius)

But it never goes beyond 0 kelvin. That is, whatever it matters,even if the universe is at the verge of a heat death,the lowest possible temperature is Zero kelvin. It will never go negative.

But why? Why it is still limited at its own death? Why universe isn't free even at its death? Why cant the universe have a negative kelvin scale temperature?

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A study on Entropy - 2

There are reversible and irreversible processes. Just as the names suggests,one can be reversed and the other can't.
But why did it tell you that now? Checking your vocabulary? Nop!
I need to make a statement that, "All the natural processes I the universe is irreversible. It can't be undone"

Burning a wooden piece, making some food, digestion, weaving some clothe,electricity,giving birth,growing,dying and almost all the natural processes are irreversible.  We can also say,almost all the reversible processes are ideal in nature or it isn't a real one. We just use it to study. Just study.
------------------

From the studies of efficiency of an engine, scientists and engineers have found that, An engine is also a thing which does an irreversible process.

Efficiency,as the word suggests is the quality or capability of something to do something efficient. 😃

For an engine,it defines how perfect it can work. There is ideal engine and real engine. Ideal engine exists only in text books for the purpose of studying as it is ideal one and real engines exists in reality. However ideal engine (which exists only in books,which are said to be the perfect role models :P ) is the more efficient than a real engine. It is like, a 1 Litre bottle can never measure 1Litre,as there will always be a manufacturing error might be ranging from microscopic level to nanoscopic or even picoscopic or so on.

The equation which describes efficiency of an engine is [ 1- Q'/Q ]
For the ideal case it can also be derived as [ 1- T'/T], where Q is representing the heat and T of course the temperature. Only for the ideal case,we can derive the equation with T from that of Q. (which means, equation of Q is the general one for all)

So [1-Q'/Q] is always less than [1-T'/T] or to be more specific, by rearranging we will get, [ Q'/T' - Q/T = 0 ]
The value of this difference always a positive one. Why? For every process we takes some energy,use some and leaves the remaining. The difference between taken energy and leftover energy will be positive right? Because that is the one which we used to does the work!

This clearly states that, the second term Q/T is smaller. For an engine,heat only flows from higher to lower temperature. Hence T<T'
For every natural processes this leftover energy,is dumping onto our surroundings,globally to the nature or.... Universally to the universe.
Hence for every natural processes little little such energies will gets dumped. [ratio of 'change in Q' to T is the relation for entropy]. As the T<T' and Q/T is entropy... Lower denominator produces higher entropy (for the same Q) or entropy is positive for every natural processes. Which means entropy is being increased always, from burning of a wooden price to burning of a star,which again means the entropy of universe is always increasing.

But what does this really mean? What does it have to do with us? Do it bothers me? Why should I care?

Know the Basic Ideas on Entropy

#Entropy is a #thermodynamic variable which most of the people defines as a 'measure of disorderness', or 'how much disorder' one state is...
For example, a particle of liquid have more order than that of a gas, or the gas molecule is more disorder. A classroom with teacher is ordered. A classroom without a teacher is more disorder,or simply the entropy is more.

There is no exact physical significance for the term entropy,how ever there are some meaning for this 'disorderness'.
Entropy being the measure of disorderness,it indirectly states the cause for order. Its like,if you are the measure of violence over a region,probably you are the reason for it to happen.

Entropy is mainly associated with heat transfer in a system. So connecting the order and heat,we define entropy as the thermal inertia or heat inertia.

The common inertia is the cause for motion. Moment of inertia is the cause for rotation. Similarly, Entropy is the cause for Heat change.

But our entire universe is a heat system. Right? Starts born,stars die,other bodies bursts, universe expands.... What does entropy have to do with all these?

--------------------------------------------------------------

There are reversible and irreversible processes. Just as the names suggests,one can be reversed and the other can't.
But why did it tell you that now? Checking your vocabulary? Nop!
I need to make a statement that, "All the natural processes I the universe is irreversible. It can't be undone"

Burning a wooden piece, making some food, digestion, weaving some clothe,electricity,giving birth,growing,dying and almost all the natural processes are irreversible.  We can also say,almost all the reversible processes are ideal in nature or it isn't a real one. We just use it to study. Just study.
------------------

From the studies of efficiency of an engine, scientists and engineers have found that, An engine is also a thing which does an irreversible process.

Efficiency,as the word suggests is the quality or capability of something to do something efficient. 😃

For an engine,it defines how perfect it can work. There is ideal engine and real engine. Ideal engine exists only in text books for the purpose of studying as it is ideal one and real engines exists in reality. However ideal engine (which exists only in books,which are said to be the perfect role models :P ) is the more efficient than a real engine. It is like, a 1 Litre bottle can never measure 1Litre,as there will always be a manufacturing error might be ranging from microscopic level to nanoscopic or even picoscopic or so on.

The equation which describes efficiency of an engine is [ 1- Q'/Q ]
For the ideal case it can also be derived as [ 1- T'/T], where Q is representing the heat and T of course the temperature. Only for the ideal case,we can derive the equation with T from that of Q. (which means, equation of Q is the general one for all)

So [1-Q'/Q] is always less than [1-T'/T] or to be more specific, by rearranging we will get, [ Q'/T' - Q/T = 0 ]
The value of this difference always a positive one. Why? For every process we takes some energy,use some and leaves the remaining. The difference between taken energy and leftover energy will be positive right? Because that is the one which we used to does the work!

This clearly states that, the second term Q/T is smaller. For an engine,heat only flows from higher to lower temperature. Hence T<T'
For every natural processes this leftover energy,is dumping onto our surroundings,globally to the nature or.... Universally to the universe.
Hence for every natural processes little little such energies will gets dumped. [ratio of 'change in Q' to T is the relation for entropy]. As the T<T' and Q/T is entropy... Lower denominator produces higher entropy (for the same Q) or entropy is positive for every natural processes. Which means entropy is being increased always, from burning of a wooden price to burning of a star,which again means the entropy of universe is always increasing. 

But what does this really mean? What does it have to do with us? Do it bothers me? Why should I care?
----------------------------------------------------

In my previous post a stated that the entropy is being increased. Not just of a engine's,but that of entire universe's.

But why do I have to care?  Does it affects me? Absolutely no!!!!
But yes!

Entropy is the measure of disorderness or it is the cause for heat exchange. We can also tell an increment in entropy will also suggests,somewhere in the universe some heat is being transferred from a high temperature to lower one. Well,heat can only go like that unless some special works (refrigeration) are done.

But still what does it costs? 
It costs nothing,but engulfs everything. Universe is expanding,making more and more space for heat to spread. And Entropy which is always increasing and increasing, reduces the total amount of higher temperature region itself. At a certain point of time (after millions of billions of earth years) universe will ask for almost every energy source for this entropy to go on increasing along with expanding universe. It is thought to be a fate of our universe,we don't know yet.

All the available energy will be used up. Which is stored as potentials,mass,heat,data's,information etc
The loss of available energy is equivalent to gain in entropy.
As #entropy is gaining , available energy reduces which in turn makes #universe a desert where everything is unique as sand,except there won't be anything to watch it.

At the maximal #entropy state all the physical variables,the temperature,pressure,composition...all will be uniquely distributed. And it will be impossible to differentiate between two points in the universe.

Scientists refers this to as Heat Death of the #Universe

The temperature at this stage will be zero kelvin (or -273 Celsius)

But it never goes beyond 0 kelvin. That is, whatever it matters,even if the universe is at the verge of a heat death,the lowest possible temperature is Zero kelvin. It will never go negative.

But why? Why it is still limited at its own death? Why universe isn't free even at its death? Why cant the universe have a negative kelvin scale temperature?

---------------------------------------------------------

I have already told that the efficiency of an ideal engine is [ 1-T'/T ] and no other engine (all other engines are real ones) have more efficiency than this one.

One of my fellow readers have asked a silly doubt,"this is all about engines right?" Yes,but an engine means a thermo dynamical observational system. This phrase doesn't digest for common people that's why I used 'engine',and it not only represent an engine of a machine or an automobile but every heat taking - giving systems.

So,there can't be more efficient engine than a ideal one. (if you have confusion about ideal and real one, think like this. Legends are ideal characters,but in real life we can't find any,as every people are real ones. There isn't any ideal legends,everyone should have any singles flaws or defects),as per the equation, the maximum value for efficiency is 1 and minimum is ofcourse 0. (how did this come? ,see the image)

What if then, the temperature becomes negative? (see the image), the efficiency is greater than 1. We just said, 1 is the maximum value and that is too ideal... How can any system ever get more efficient than 1? How can one be more legendious than legend? How can you be more yourself than yourself? How can water be more watery?

So the concept contradicts reality,hence the assumed thing is not real or generally,the negative temperature in kelvin scale is impossible.

This doesn't mean negative temperatures are impossible,after all its just temperature and positiveness and negtiveness are what we attributed to them. And this is only valid in kelvin scale ,not in Celsius or Fahrenheit scale. Kelvin is the general scale,so that's how it become more important.

But what if,there is a particular case in which negative kelvin exists?

If the subsystem of a main system is considered isolated from it,the nucleus can have a negative temperature. That's what Ramsey in 1956 put forwarded. 

The negative temperature on a whole system is an invalid idea,where as for certain cases,its possible.

Ramsey's experiments shows that possibility. For normal purposes only the positive temperatures are possible.

The negative temperatures are more hotter than positive ones. At higher temperatures the specific heat,which is the heat energy supplied to increase a degree kelvin,becomes approximately zero or gets nullified. Or a very very small energy s needed to increase the temperature into infinity. This allows us to form the negative temperature scale too. Remember,this is only valid for isolated subsystems within crystals,lattices

As it is not a significant thing in normal physical universe,I am not going further.

Total Eclipse of the Sun; Sravana 30, 1939 S.E.; August 21, 2017, Monday

Not visible in India

Area of Visibility 

         

The eclipse is visible in the region covering Hawaii, N. E. Pacific Ocean, North America, Central America, northern parts of South America, Westernmost tip of Europe and W. Africa.

The path of total eclipses passes through a narrow path in north Pacific Ocean, in the middle of United States and North Atlantic Ocean.            

 

  CIRCUMSTANCES  OF  THE  ECLIPSE

	Universal Time			Indian  Standard Time
	d	h	m	d	h	m
Eclipse begins	21	15	47.0	21	21	17.0
Central eclipse begins	21	16	49.1	21	22	19.1
Greatest eclipse*	21	18	25.5	21	23	55.5
Central eclipse ends	21	20	02.1	22	01	32.1
Eclipse ends	21	21	04.3	22	02	34.3

 

*Magnitude of the eclipse = 1.030, Maximum duration of total phase = 2 min 36.0s

Partial Eclipse of the Moon; Sravana 16, 1939 S.E.; August 7, 2017; Monday

Visible in India Area of Visibility                The Eclipse will be visible in the region covering Western Pacific Ocean, Oceania, Australasia, Asia, Africa, Europe and Antarctica. The places from where the beginning of the umbral phase is visible at the time of moonset are western parts of North Pacific Ocean and South Pacific Ocean. The places from where the ending of umbral phase is visible at the time of moonrise are north western parts of Africa, eastern parts of Spain, France and Germany.    CIRCUMSTANCES  OF  THE  ECLIPSE     Universal Time Indian  Standard Time   d  h m d  h  m Moon enters penumbra 7 15 48.1 7 21 18.1 Moon enters umbra 7 17 22.3 7 22 52.3 Middle of the eclipse* 7 18 20.5 7 23 50.5 Moon leaves umbra 7 19 18.7 8 00 48.7 Moon leaves penumbra 7 20 52.9 8 02 22.9   *Magnitude of the eclipse = 0.251 (Moon's diam = 1.0).

Annular Eclipse of the Sun; Phalguna 7, 1938 SE; February 26, 2017; Sunday

The eclipse is not visible in India.

 

Area of Visibility 

           

The eclipse is visible in the region covering southern South America, Antarctica, southern Africa, the south Pacific Ocean and the south Atlantic Ocean.

The path of annularity passes through  the region covering the south Pacific Ocean, Chile, Argentina, the Atlantic Ocean and  west part of southern Africa.

 

 CIRCUMSTANCES  OF  THE  ECLIPSE

	Universal Time			Indian  Standard Time
	d	h	m	d	h	m
Eclipse begins	26	12	10.9	26	17	40.9
Central eclipse begins	26	13	16.1	26	18	46.1
Greatest eclipse*	26	14	53.4	26	20	23.4
Central eclipse ends	26	16	30.9	26	22	00.9
Eclipse ends	26	17	36.0	26	23	06.0

Sky Chart For The Month of January, 2017

ASTRONOMICAL BULLETIN FOR JANUARY 2017

The Moon

First Quarter occurs on 6th at h. 1-17 I.S.T.	Full moon occurs on 12th   at h. 17-04 I.S.T.
Last Quarter occurs on 20th at h. 3-43 I.S.T.	New moon occurs on 28th at h. 5-37 I.S.T.
The Lunar Crescent becomes first visible after the New Moon day in the evening of 29th.
The Moon is at Perigee or nearest to the Earth on 10th and at apogee or farthest from the Earth on 22nd.

The Moon passes about 2º north of Venus on 2^nd, about ½ º north of Neptune on 3^rd, very close tonorth of Mars on 3^rd, about 3½ º south of Uranus on 6^th, about 2½ º north of Jupiter on 19^th, about 3½ º north of Saturn on 24^th, about3½º north of Mercury on 26^thand about ½ º north of Neptune on 30^th.

 The Earth

The Earth is at Perihelion position in its orbit or reaches nearest to the Sun on 4^th.

The Planets

Visibility of Planets:

Mercury: The planet is too close to the Sun to be visible up to 1^st of the month. Thereafter it rises before sunrise and remains visible till the beginning of morning twilight for the remaining days of the month. It rises about ½ hour to 1½ hours before it during the period. The motion of the planet becomesDirect with respect to the Earth from 8^th. It is in Greatest Western Elongation of about 24º from the Sun on 19^th.

Venus: The planet is a brilliant object visible in the western sky after sunset and sets about 3½ hoursafter it throughout the month. . It is in Greatest Eastern Elongation of about 47º from the Sun on 12^th.

Mars: The planet is visible in the western sky after sunset and sets about 2½ hours to 3 hours before local midnight throughout the month.

Jupiter: The planet rises about ½ hour before local midnight to close to local midnight time uptofirst quarter of the month, from close to local midnight time to ½ hour before it uptosecond quarter of the month, about ½ hour to 1 hour before it upto third quarter of the month and about 1 hour to 1½ hours before it for the remaining days of the month. The planet is in Quadrature with the Sun on 12^th.

Saturn: The planet rises before sunrise and remains visible till the beginning of morning twilight throughout the month. It rises about 1½ hours to 2 hours before it upto first quarter of the month, about 2 hours to 2½ hours before it upto second quarter of the month and about 2½ hours to 3 hours before it for the remaining days of the month.

Uranus: The planet sets about ½ hour after local midnight to close to local midnight time uptofirst quarter of the month, from close to local midnight time to ½ hour before it upto second quarter of the month, about ½ hour to 1hour before it upto third quarter of the month and about 1 hour to 1½ hours before it for the remaining days of the month. The planet is in Quadrature with the Sun on 10^th.

Neptune: The planet sets after sunset throughout the month. It sets about 4½ hours to 4 hours after it upto first quarter of the month about 4 hours to 3 hours after it upto third quarter of the month and about 3 hours to 2 hours after it for the remaining days of the month.

Conjunction of Planets

Mars passes very close to south of Neptune on 1^st.

Venus passes about ½º north of Neptune on 13^th.

Jupiter passes about 3½º north of Spica (Chitra) on 21^st.

Planets	Planets in Zodiacal Constellation	Magnitude
Mercury (Budha)	Remains in Sagittarius (Dhanus).	+2.0 to 0.0 0.0 to -0.2
Venus (Sukra)	Moves from Aquarius (Kumbha) toPieces (Mina).on 27th.	-4.4 to -4.7
Mars (Mangala)	Moves from Aquarius (Kumbha) toPieces (Mina).on 20th.	+0.9 to +1.1
Jupiter (Brihaspati)	Remains in Virgo (Kanya).	-1.9 to -2.1
Saturn (Sani)	Remains in Sagittarius (Dhanus).	+ 0.5
Uranus	Remains in Pieces (Mina).	+6.0
Neptune	Remains in Aquarius (Kumbha).	+ 8.0

Source : : Director
Positional Astronomy Centre
IndiaMeteorological Department
SaltLake, Kolkata - 700 091.

A user experience on 'Introduction to Electrodynamics' by David J Griffith

It is an awesome and best of all the text books i ever had. Griffith,he is a talented artist on physics. He just didn’t wrote a text,rather he wrote something, a student want. For me,i have always doubts regarding the concepts of electrodynamics,however Griffith connects the mathematics including vectors,integration,differentiation to the physics and explain physical reality. the most lovely thing is that,his easiest ways of imaginations,taking of models and examples and silly jokes in between. 

A student who is seeing that book fro the first time,will sure get a heart attack,because of the notations and weird mathematical notation,but however if you continue struggling for a little time to understand the language of author,there is nothing more clearer that this book to study electrodynamics. 

The problems solved and unsolved,are the dictionary! you cannot expect any new question for any exam all over the world,outside this book,because almost all the types are explained. You can buy the solution book for getting the solutions to unsolved exercises.

However ,hoping the same,i bought Introduction to Quantum mechanics by the same author. It was a hell! to be frank, the theories in that was awesome,will take hours to grasp,but it will stay for long time. 

However,no one could possibly solve any problems in it. Its that much,not hard but confusing and literally we will feel WTF! But,still its very awesome to read and spend our time engulfed in the mesmerising thoughts of quantum mechanics.