MEASUREMENT AND UNIT

Select the blanks for answers:-
=> Any measurable or quantifiable property of the physical world is called a physical quantity.
=>Some physical quantities are length, mass, time, temperature, distance, etc.
=>Some unmeasurable physical properties are anger, love ,greed, hatred, etc.
=> Two types of physical quantities are there-Scalars and vectors.
=> Scalars are the physical quantities that are represented by their magnitude only and hence cannot be resolved into components .
=>Examples of scalar quantities include mass, time, length, energy, temperature, etc.
=>A vector is a physical quantity having a magnitude resolvable into multipath components and hence requires direction to be represented.
=> Examples of vectors include force, velocity, acceleration, etc. => Force needs to be defined in terms of magnitude in N and also the direction in which it acts.
=> Force needs to be defined in terms of magnitude in N and also the direction in which it acts.
=>Velocity is expressed in ms-1 and needs a direction in which the body is travelling.
=> The vector → Q can be subtracted from vector → P if it has a direction opposite to → P . The magnitude of the resultant vector will be equal to the difference of magnitudes of the subtracting vectors and the direction will be that of the greater vector.
=> Symbolically, a vector quantity is expressed as a line segment with an arrow. The length of the line segment represents the magnitude of the vector quantity whereas the arrow head and orientation of the line segment gives its direction.
=> A vector having a zero magnitude and arbitrary direction is called a null vector.
=> The result of the sum of a vector and its negative vector is always a null vector. A+ (-A) =0
=> Measurement of any physical quantity involves comparison with a certain basic, arbitrarily chosen, internationally accepted reference standard. This is called unit.
=> The result of a measurement of a physical quantity is expressed by a number (or numerical measure) accompanied by a unit.
=> Although the number of physical quantities appears to be very large, we need only a limited number of units for expressing all the physical quantities, since they are inter- related with one another. Besides , some physical quantities are arbitrarily regarded fundamental and can be used to form most other derived quantities.
=>The units for the fundamental or base quantities are called fundamental or base units. => The units of most physical quantities can be expressed as combinations of the base units. Such units obtained for the derived quantities are called derived units.
=>Physical quantities are either “scalar” or “vector” .
=>Vector quantities are important in the study of motion.
=> Some examples of vector quantities include force, velocity, acceleration, displacement, and momentum.
=>A quantity is a vector if it has a direction associated with it.
=>The speed is just the magnitude of the velocity in a certain direction. So speed is a scalar quantity, but velocity is a vector .
=>If a car has a velocity of 40 mph east, it has a speed of 40 mph.
=>A vector is drawn as an arrow with a head and a tail. The magnitude of the vector is often described by the length of the arrow. The arrow points in the direction of the vector. =>Vectors are generally written as boldface letters. They can also be written with an arrow over the top of the letter.
=>”The football player was running 12 miles an hour towards the end zone.”-
This is a vector because it represents a magnitude (12 mph) and a direction (towards the end zone). This vector represents the velocity of the football player. = “The volume of that box at the west side of the house is 12 cubic feet”. –
This is a scalar. The location of the box has nothing to do with the direction of the volume which has a magnitude of 12 cubic feet.
=> “ The temperature of the room was 15 degrees Celsius.” – This is a scalar, there is no direction.
=> “ The vehicle accelerated north at a rate of 4 meters per second squared.” –
This is a vector as it has both direction and magnitude. We also know that acceleration is a vector quantity.
=>Unit vectors are vectors with a magnitude of 1.
=>Unit vectors are used to define direction.
=>The credit for inventing vectors goes to Irish physicist William Rowan Hamilton.
=>Vectors can be defined in two dimensional or three dimensional space.
=>Three different systems of units for measurement -the CGS, the FPS (or British) system and the MKS system were in use extensively till recently.
=> In CGS system, the base units for length, mass and time were centimetre, gram and second respectively.
=>In FPS system , the base units for length, mass and time were foot, pound and second respectively.
=>In MKS system , the base units for length, mass and time were metre, kilogram and second respectively.
=>The system of units which is at present internationally accepted for measurement is the Système Internationale d’ Unites (French for International System of Units), abbreviated as SI.
=>In SI, there are seven base units.
=> Seven base units of the SI : metre (length), kilogram (mass), second (time), ampere (unit of electricity), kelvin (temperature), mole (amount of substance) and candela (light intensity).
=> Mnemonic for Seven base units of the SI = mksakmc
=>There is no physical quantity which has dimensions but no units. =Units are product of dimensional analysis.
=Units are product of dimensional analysis.
=> Besides the seven base units, there are two more units for two dimensionless physical quantities- plane angle and solid angle.
=>Plane angle is the ratio of length of arc to the radius.
=>The unit for plane angle is radian with the symbol rad .
=>The unit for the solid angle is steradian with the symbol sr. =>Both radian and steradian are dimensionless.
=>Both radian and steradian are dimensionless.
=>Both radian and steradian are dimensionless.
=>The definitions of base units are revised to keep up with the progress of the measuring techniques.
=> The metre (m) is the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second.
=> The kilogram (kg) is equal to the mass of the international prototype of the kilogram (a platinum-iridium alloy cylinder) kept at international Bureau of Weights and Measures, at Sevres, near Paris, France.
=>The second(s) is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium-133 atom. => The ampere(A) is that constant current which, if maintained in current two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 metre apart in vacuum, would produce between these conductors a force equal to 2×10^–7 newton per metre of length.
=> The kelvin (K) is the fraction 1/273.16 of the thermodynamic dynamic temperature of the triple point of water.
=> The mole (mol) is the amount of substance of a system, which contains substance as many elementary entities as there are atoms in 0.012 kilogram of carbon – 12.
=> The candela (cd) is the luminous intensity, in a given intensity direction, of a source that emits monochromatic radiation of frequency 540×10^12 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.
=>Some units like mole are retained for general use (Though outside SI).
=> When mole is used, the elementary entities must be specified. These entities may be atoms, molecules, ions, electrons, other particles or specified groups of such particles.
=> A metre scale is used for lengths from 10^–3m to 10^2 m.
=>A vernier callipers is used for lengths to an accuracy of 10^–4 m.
=>A screw gauge and a spherometer can be used to measure lengths as less as to 10 ^–5m.
=>To measure lengths smaller than 10 –5m, we make use of some special indirect methods. => Large distances such as the distance of a planet or a star from the earth cannot be measured directly with a metre scale. An important method in such cases is the parallax method.
=>The parallax is the apparent displacement of an object as seen from two different points that are not on a line with the object.
=> If we look at a fixed object through a single eye while closing the other , with the change of eye the position of the object against some specific point on the background seems to change.This is a familiar example of parallax.
=>In parallax, the distance between the two points of observation is called the basis.
=In the simplest parallax example, the basis is the distance between the eyes.
=> To measure the distance D of a far away planet S by the parallax method, we observe it from two different positions (observatories) A and B on the Earth, separated by distance AB . We measure the angle between the two directions along which the planet is viewed at these two points.
=> To measure a very small size like that of a molecule (10^–8 m to 10^–10 m), we have to adopt special methods.
=> For visible light the range of wavelengths is from about 4000 Å to 7000 Å.
=>1 angstrom = 1 Å = 10^-10 m. =>As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a higher resolving power than light microscopes and can reveal the structure of smaller objects.
=>As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a higher resolving power than light microscopes and can reveal the structure of smaller objects.
=>As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a higher resolving power than light microscopes and can reveal the structure of smaller objects.
=>The sizes of the objects we come across in the universe vary from the size of the order of 10^–14 m of the tiny nucleus of an atom to the size of the order of 10^26 m of the extent of the observable universe. =>1 fermi = 1 f = 10^–15 m
=>1 angstrom = 1 Å = 10^–10 m
=> 1 astronomical unit = 1 AU (average distance of the Sun from the Earth) = 1.496 × 10^11 m
=> 1 light year = 1 ly= 9.46 × 10^15 m (distance that light travels with velocity of 3 × 10^8 m s–1 in 1 year)
=>Parsec is the distance at which average radius of earth’s orbit subtends an angle of 1 arc.
=>The parsec equals 3.26 light-years.
=>1 astronomical unit = 1.581 × 10-5 light-years.
=>The prefixes are used in very small as well as very large quantity.
=>Physics deals with matter, energy and their interaction.
=A microgram or microgramme (μg) is equal to one millionth (1×10^−6) of a gram.
=A microgram or microgramme (μg) is equal to one thousandth of a milligram. [{(µg comes from the Greek letter mu, where µ means “small”.)}] => 32 × 10^-10 kg =3.2 µg.
=>The quantities 123.0,12.30,1.230, 2.000 and .2000 all contain 4 significant figures.The first three numbers are known with certainty and the final number is always taken as significant.
=> A zero used to fix a decimal point is never significant.
=>A trailing zero to “count” as significant, must be followed by a decimal.
=>Writing just “5000” would give us only one significant figure i.e. 5.
=>The quantities 0.456, 0.0456 , 0.00456 and 45600 all contain 3 significant figures.All exponential zeros are insignificant. =>0.000000001 has only one significant figure; the remaining zeros were used to fix the decimal point.
=>Significant figures in 0.02020=5.
=>Significant figures in 70.010=5
=>Significant figures in 0.03000=4
=>As an exponential number 0.03000 can be represented as 3.000 x 10^-2.
=>Zeros within a number are always significant.
=>The quantities 609, 60.9, 6.09 and 0.609 all contain 3 significant figures since the 0 between the 6 and 9 is significant. The number 609 means that the true value rests somewhere between 608 and 610, thus, the zero is known with certainty and is significant.
=> The number of significant digits in 0.073 =2.
=>Geophysics deals with the study of internal structure of earth.
=> A physical balance is a modified beam balance to measure small masses more accurately by comparison.
=>Amount of a substance in terms of numbers is measured in mole.
=>While measuring length the eye must be kept above the scale.
=>A screw guage measures the diameter of a wire or the thickness of a metal sheet. =>The study of the nature of heat, modes of transfer and effects of heat is studied under the branch named as heat .
=>The number 0.0000748 in scientific notation is 7.48 * 10^ -5.
=>Non-zero digits are always significant .
=> The quantities on the basis of which other quantities are expressed are called base quantities .
=>Plasma physics deals with the production and properties of the ionic state of matter .
=>A stop watch measures the time interval of an event .
=> The amount of substance is a base quantity.
=>A spring scale can not measure mass, only weight.
=> Object’s mass when measured with the same beam balance and standard mass is the same everywhere.
=> Object’s weight even when measured with the same spring scale varies with gravity.
=> A weighing scale actually measures the value of Normal Reactions acting on it. => N (Normal Reaction) =mg.
=> The weighing scales are measured in ‘KG’ instead of ’N’ (Newton) because the calibration scale is set to 1: 9.81 ratio.
=> 981 N force on spring scale is displayed as 100 kg ,the mass part only.
=> g= 9.81 N/m2 on the earth. =>Spring scale shows different value of mass on another planet.
But a two-pan balance gives the same reading.
=> Weighing Scales actually output weight depending on the force exerted on it, but displays it as mass (just by dividing it by a constant=9.8).
=> We need to multiply the displayed value on a spring scale by 9.8 to calculate the actual Weight in SI units.
=>10kg*9.81m/s2=98.1N is shown as 10 kg by a spring scale.
=> In a gravityless environment, a weighing scale is useless to measure mass.
=> In a gravityless environment, we use an inertial balance. For a given stiffness (spring constant) of the spring; the frequency of vibration of the spring calculates the mass of a body.
=> Unlike a spring scale ,a beam balance directly measures mass.
=> A spring scale measures weight by reporting the distance that a spring deflects ( Hooke’s law) due to a load under gravity.
=>The deflection is proportional to the force (weight) which in turn is proportional to the mass.
=> Smallest measurement an electronic balance can take is 1/1000 g = 0.001 g .
=> A measuring cylinder is a graduated glass cylinder marked in millilitres.
=> The science that deals with the study of non-living things is known as physical science .
=>The least count of screw gauge is 0.01 mm.
=> A refrigerator is made on the principles of thermodynamics .
=>The distance of moon from earth is 3.84 * 10 8 m.
=> In screw gauge a thimble around its one end has 100 divisions.
=>One division of Vernier scale is of 0.9 mm .
=> If zero line of the vernier scale is on the right side of the zero of the main scale, then zero error will be positive .
=>Zeros used for spacing the decimal point are non-significant .
=>All the accurately known digits and the first doubtful digit in an expression are known as significant figures .
=> The final zeroes after decimal are significant.
=> The least count of physical balance is 0.01 g.
=>The study of fourth state of matter is called plasma physics.
=>An interval of 300µs is equal to 3 × 10 -4 s.
=> An instrument used to measure small lengths such as internal or external diameter or length of a cylinder, etc. is called vernier callipers.
=>The prefix for 4800000 W is 4800 kW.
=> In screw guage, the distance between consecutive threads on the spindle is 1 mm.
=> All physical quantities are measurable.
=> A worldwide system of measurements in which the the units of base quantities were introduced is called international system of units .
=>By converting 3 700 000 Watt into kilowatt, we get 3 700 kW .
=> The study of motion of objects, its causes and effects is called mechanics . => Harry claimed that the diameter of a wire is 1.042 using vernier callipers. Upto what extent he is right is 1.04 cm.
=> The words or letters added before a unit and stand for the multiples or sub-multiples of that unit are called prefixes.
=>10 vernier scale divisions coincide with 9 main scale divisions.
10 vsd=9 msd
1 vsd=.9 msd
LC= 1MSD-1VSD
LC=1MSD-.9MSD=.1MSD ( .1 mm).
=> The least count of Vernier calipers is 0.01 cm=0.1 mm.
=>The “seconds in a day” can be written in standard form as 8.64 × 10 5 s .
[{(A day,243 Earth days, on Venus lasts longer than a year, 225 Earth days.)}]
=>A digital wrapper is 4.5 cm long and 5.9 cm wide. Its area upto significant figures will be 26.55 cm².
=>Physical sciences were divided into 5 disciplines.
=>The smallest change a sensitive beam balance can record is 100 mg.
=> By using prefixes, we can write 335 × 10 -8 s as 3.35 µs .
=>When a standard is set for a quantity, then the standard quantity is called a unit .
=> The study of the internal structure of the Earth is known as geophysics.
=>A fundamental quantity belongs to a typical class, each of them having no dependence with other fundamental quantities.
=>The typical attribute that is common to a class of physical quantities is what is called their dimensionality.
=>A typical dimension represents
a typical class of physical quantities.
=>The dimension of a body means how it is relatable in terms of base quantities.
=> The dimension of a physical quantity is represented by the powers to which the fundamental quantities are raised.
=> The seven fundamental quantities are enclosed in square brackets [ ] to represent its dimensions.
=> The dimension of Length is described as [L].
=> The dimension of time is described as [T].
=> The dimension of mass is described as [M].
=> The dimension of electric current is described as [A].
=> The dimension of the amount of quantity can be described as [mol].
=> The dimension of temperature is [K].
=> The dimension of luminous intensity is [Cd].
=> The volume of a solid is the product of length, breadth and its height.
As volume is dependent on mass and time, the final dimension of volume will be [M]0[L]3[T]0

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Aristotle, the great categoriser, distinguished life from non-life mainly by the tendency of living things to be drawn towards a future goal.

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Since particles of matter follow physics not goals, the inner drive of organisms is not fundamental but  emergent from evolutionarily demanding arrangement of matter.

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Since particles of matter follow physics not goals, the inner drive of organisms demands a top-down explanation.

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Darwin knew that his theory of evolution explains how life got diverse  and not how it started in the first place. So he named his book ‘The Origin of Species’ instead of  “The Origin of Life.”

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We still need a new Darwin to write “The Origin of Life” or “The Origin of Matter”.

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“One might as well speculate on the origin of matter.”

-Charles Darwin

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Editing the genes of embryos will  change our species’ evolutionary trajectory.

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Though gene-editting  can improve the human race, the strengths of our diversity might be lost.

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Gene-editting might violate the rights of already vulnerable populations.

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Humility is the acknowledgement of our ignorance. Gene-editting demands humility to ensure its risks are heeded.

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Gene-editting  demands altruism to ensure its benefits are equitably distributed.

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Darwinian evolution is an entropic phenomenon.


Inspire kids to become scientists by saying that…..…………………………………………

Aristotle, the great categoriser, distinguished life from non-life mainly by the tendency of living things to be drawn towards a future goal.

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Since particles of matter follow physics not goals, the inner drive of organisms is not fundamental but  emergent from evolutionarily demanding arrangement of matter.

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Since particles of matter follow physics not goals, the inner drive of organisms demands a top-down explanation.

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Darwin knew that his theory of evolution explains how life got diverse  and not how it started in the first place. So he named his book ‘The Origin of Species’ instead of  “The Origin of Life.”

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We still need a new Darwin to write “The Origin of Life” or “The Origin of Matter”.

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“One might as well speculate on the origin of matter.”

-Charles Darwin

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“Our  search for an evolutionarily meaningful existence becomes an epic romance when we tap into the existential agency.”

-NABA KUMAR GARAI (https://wondernspeculate.org/)

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Nothing is ‘ARTIFICIAL’ in evolution. Even our androids, computers,  spacecrafts or robots are biological extensions evolving ‘NATURALLY’.

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When replication hosts  some existentially self-amplifying copying errors, it is called ‘evolution’.

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A replicator is anything that gets, directly or indirectly, copied.

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Survival of the fittest amounts to survival of the best replicating mechanism. It has nothing to do with strength, agility, longevity, happiness  or extraordinary intelligence. Even a shorter-lived replicator that is better at being copied become more abundant than a durable, long-lived one.

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Biological evolution is actually a contest between pieces of DNA to see which of them could make the most copies of themselves.

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In Chinese dualistic cosmology, yin and yang -two opposite but complementary tendencies produce everything that comes into existence.

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Evolution is the creative and entropy is the destructive force of the universe. Yin and yang of existence!

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The study of evolution is the study of replication.

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A virus, whether genetic or memetic,  exists because a copying mechanism might not be equipped with a screening plugin.

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A virus is one of the mechanisms for copying and dispersing information in the universe.

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A virus is one of the universal replicators for copying and dispersing information in the universe.

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The human mind is the most advanced copying mechanism of all.

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The four variedly robust   characteristics of a replicator: penetration, copying, issuing instructions, and spreading.

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Human culture is best identified as a meme pool.

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We should put our meme pool to work for humanity’s best interests.

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Since our biological default plugin for understanding isn’t designed to understand what happens over millions or billions of years, Darwinism seems weird.

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Things or forms change. It is called entropy. By ‘evolution’, we just  make a distinction between the winners ( which continue to exist, grow, split and replicate), and the losers. When such a replicating machinery secures its existence by adapting to environmental feedbacks, we get something upon which we ascribe a special name called ‘life’.

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Asymmetries or things level out ( get simpler or symmetric) over time, like sand castles on a beach.

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Evolution is a scientific model of how things become more asymmetric and

complex; entropy describes how things become symmetric and simpler.

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Evolution is the opposite of entropy.

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Replicators are medium-born. Medium proliferates them. But they will use any medium extending their circulation and reproduction. After finding a better medium  replicators quickly leave the old medium without any gratitude.

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A medium serves as the host for replicators.

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Replicators cannot survive without a host.

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A host/medium/container/transmitter  is quickly chosen by replicators whenever it is available and effective.

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A sort of memetic spell forces us to share posts on social media. This 21st century has already become a  digital meme pool. Internet users(directly or indirectly) serve as mere links in a chain of host media for the passage of memetic information. Too much automation might one day replace our species with artificially intelligent robots. Replication will continue as well, or even better.

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Our instinctive virtues and vices are actually autonomous algorithms (mechanistically blind evolutionary plugins) that help us survive in brutally   indifferent Darwinian struggle.

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What is most radical about Dawkins’ theory is that it reduces existence to the level of mere media- as if things exist only to  facilitate the replication and passage of information.

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We needed Darwin to show us that life is the gift of mechanical evolution. We needed  Dawkins to tell us that neither individuals nor species but  replicators serve as the hot iron to bear the blind blows  of  evolutionary hammer.

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In Dawkins’s theory, very little difference exists between humans and machines, animals and ideologies, insects and internet memes— all are just containers of some replicators.

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In Dawkins’s theory, man is just one of many potential host media for transmission and reproduction of “content”.

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The genetic natural selection is a special case of a general ( universal) Darwinism with some replicator as a unit of natural selection.
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Where there is any natural selection, there is some replicator. If any occasional error in replications influences its own probability of replication, that particular ‘error’ gets selected as a mainstream or natural continuation.
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Since Darwin’s theory of evolution is substrate-neutral, it universally applies to organic, inorganic and even cultural systems.

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Our visible cosmos itself seems to be an evolving system.
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Memetics is Universal Darwinism applied to human culture.
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According to James Gardner and Lee Smolin, the visible universe itself is a Darwinian adaptation.

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Till now 99 percent earthly organisms have died childless.
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A man has billions of ancestor – from single cells to worms to fish to reptiles to mammals to primates.
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A chemical feedback system has evolved into ‘life’.
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Biological phenomena belong to a  fundamental physical process called ‘evolution’.

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Biological phenomena evolved from physical feedback loops.

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Male genes with even slightly  aesthetic bent are often selected by female birds and animals.
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Quantum fluctuation => Cosmic Inhomogeneities => Gravitational collapse => Star => Heat => Photons  disequilibrium gradient =>Electron disequilibrium gradient  => Proton gradient => Growth  => Replication => Natural selection
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Darwinian evolution is an entropic phenomenon.


A many-particle system is driven away from equilibrium, or evolve towards the equilibrium due to an interaction with an environment.


Darwinian evolution is explained by the 2nd law of thermodynamics.
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“I may not have been sure about what really did interest me, but I was absolutely sure about what didn’t.’

-Albert Camus

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An organism is lucky enough to belong to a logical process called ‘cosmos’.

Physical, chemical, and biological processes occur outside the thermodynamic equilibrium.

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Matter and energy are not things but physical quantities!

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Matter and energy are neither created nor destroyed, only transformed. It’s the first law of thermodynamics!

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In any transformation of energy, some part of the free energy gets too dispersed/bound to accomplish any work! It’s the second law of thermodynamics!

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Enormous amount of heat energy is contained/bound  in the world’s oceans and atmosphere!

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We can gather bound energy back together only at the cost of a greater expenditure of energy!

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The second law of thermodynamics is the only physical law of universal

content that describes, at least probabilistically/statistically, an irreversible process!

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The second law of thermodynamics had challenged the certainty of Newtonian mechanics before quantum mechanics!

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Darwinian evolution is an entropic phenomenon.

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The Second Law of Thermodynamics says that all complex things in a closed system like our universe will grow less complex, until everything is a cold soup of individual particles, unmoving. Time itself will effectively stop.
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The Universe is a closed system. There is no energy bleedover from or to other universes that might exist.
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The Universe is a simple system because it encompasses all that is.
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Energy enters and leaves the Earth all the time. Order can and does increase in such a local area. Complexity can arise from less complex things.
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Entropy is not a measure of randomness or disorder.
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The law of entropy is better read as “there is a high probability that entropy always increases”. It’s not physics, but probability that governs this.
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Entropy can decrease. It’s highly improbable but not impossible.
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The conservation of energy demands, that the speed of a thrown up ball must slow down as it gains height. When it loses height the speed increases. But alas! Some of the energy is given to the air molecules, but on it’s way back, the air molecules don’t give back the energy, so the situation is not really getting reversed.
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The conservation laws don’t tell why things change in a particular manner as time moves forward. It turns out that there is nothing special, it is just a game of probability.
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Due to probability, it’s more likely that coins starting with ‘all heads up’ after flipping becomes ‘some heads up and some heads down’ and the reverse (although allowed by the rules of physics) is highly unlikely (but not impossible).
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There is only one way to get the ‘all heads up’. Hence it is the lowest entropy state. There are 252 ways to get the ‘5 heads up and 5 tails up’ . It’s maximum entropy state.
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Say you have 100 trillion coins. After flipping them all, you will get about half a trillion H and half a trillion T. We might have a few 10’s of billion extra H, but overall it’s a tiny fraction and can be neglected. This explains why locally entropy could decrease, but globally it always increases.
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Entropy is not really about energy, it’s about no. of ways in which you can arrange something.
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More concentrated energy means lower entropy. More distributed means higher entropy. So concentrated energy tends to get more distributed over time. Living things exist because they are excellent at distributing energy of universe.
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Since our universe has grown, there is more room and hence more no. of ways to arrange the stuff. Hence the universe is growing in size and entropy.
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Since things are always changing in the higher entropy direction, we can distinguish between forward and reverse time.
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There might be changes happening locally .Only over all it’s pretty much half trillion H and half trillion T. However on a universal scale, there wouldn’t be any changes happening, and time would cease to exist.
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Entropy is how much energy in a system is unavailable for anything useful. Energy, on the other hand, is the ability to actualize changes to a system; the amount of energy in a system is the total amount of changes that can be made to it.
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The total amount of changes that can be made to a system (which is hypothetically infinite) is conserved; can’t increase, can’t decrease, etc. Entropy increases because all of that energy is becoming more and more unavailable for mechanical purposes.
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Thermodynamics envelopes Darwinian theory.
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The laws of thermodynamics can offer an explanation of biological evolution.

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“Thermodynamics is the only physical theory of universal content which, within the framework of the applicability of its basic concepts, I am convinced will never be overthrown.”
– Albert Einstein

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In mathematical and physical modelling, a hydrogen atom’s proton, a hydrogen atom’s electron and a planet are often treated each as an isolated system.
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The traditional  matter/mind or living/non-living  dichotomy is a false dichotomy. Even intentionality  can be understood as  complex constructions of simpler properties of nature such as self-organization and thermodynamic directionality.
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The second law of thermodynamics demands that for a closed system—like a gas in a box, or the universe as a whole—disorder must increase over time.
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The second law imposes an irreversibility on the behavior of large groups of particles, allowing us to play with words like “past,” “present,” and “future.”
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Organisms are open systems. They exchange both matter and energy with their surroundings.


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The earth is a closed system
that can exchange energy with it’s environment but not matter.
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A Thermometer is a Closed System.
The cardiovascular systems of humans are closed, meaning that the blood never leaves the network of blood vessels .
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Erwin Schrödinger recognized that living organisms, unlike a gas in a box, are open systems.
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Definitions help us  learn a new subject.

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A  system  is something  we identify or prepare in order to do experiments and make observations.
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Nothing is perfectly isolated from its surroundings.
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A system is the part of the universe we wish to study. The surroundings is  the rest of the universe.
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If a system is isolated, then nothing can enter or leave.
When only energy can be exchanged, the system is called closed.

When both matter and energy can be exchanged, the system is called open.

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Thermodynamic dissipation  provides a physical-chemical framework  for understanding the origin and evolution of life.


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Ilya Prigogine’s Non-linear Classical Irreversible Thermodynamics shows that “spontaneous” macroscopic organization  across space and time can occur within a system subjected to an external chemical potential.

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Macroscopic  “spontaneous” dissipative structuring is identical to entropy production.
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In an equilibrium model, planets stay in their fixed orbits because of two equal and opposite forces: the velocity of their forward motion taking  them away from the sun, and force of gravity pulling them toward to the sun.

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A bathtub with its drain closed and its faucet shut off is in static equilibrium. When we unplug the drain and turn on the faucet so the same amount of water comes in and goes out, we see dynamic equilibrium at work.

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Complex adaptive systems have  many parts that continually modify their behavior as they respond to changes in their environment. Examples of complex adaptive systems include the human nervous system, political systems , social structures and even stock market.

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Newtonian system, of which equilibrium is one part, has been our model for how to think about the world for three hundred years. Complex adaptive systems might one day replace such old fashioned thinking.
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Only disequilibrium exists.
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Physical, chemical, and biological processes occur outside the thermodynamic equilibrium.

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A many-particle system is driven away from equilibrium, or evolve towards the equilibrium due to an interaction with an environment.

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“You should try to take the set of actions that are likely to prolong civilization, minimise the probability of a dark age, and reduce the length of a dark age if there is one.”
-Elon Musk
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Reality is not any particular existence.

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Life, a particular existence, can’t imprison reality’s entirety.
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The purpose of life decidedly amounts to inventing, if not discovering, the purpose of life.

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“My favorite philosopher is Douglas Adams.”

-Elon Musk
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Elon Musk, as an existentially-torn teenager, embraced Douglas Adams’ philosophy summed up in the line: “The universe is the answer; what are the questions?” Perhaps, we still don’t know actually what to ask.

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To ask better and better existential questions we have to eternally expand our collective intelligence.

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“If we expand the scope and scale of consciousness, then we are better able to understand what questions to ask. We’ll learn more, we’ll become more enlightened. And so we should try to do the things that expand the scope and scale of consciousness.Becoming a multi-planet species and ensuring that we have a sustainable climate on Earth, these are very important to that overarching philosophy.”

-Elon Musk

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Models of reality can be ‘reality’ Itself.

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Models might be what there actually is.
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Modern science sprouts from empirical commentaries on ancient philosophies.

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Elon Musk in his teens read “The Hitchhiker’s Guide to the Galaxy” as a helpful existential philosophy.
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“I guess when I was around 12 or 15…I had an existential crisis, and I was reading various books on trying to figure out the meaning of life and what does it all mean? It all seemed quite meaningless.”

-Elon Musk

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“If you can properly phrase the question, then the answer is the easy part.”

-Elon Musk

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“So, to the degree that we can better understand the universe, then we can better know what questions to ask, then whatever the question is that most approximates: What’s the meaning of life?”

-Elon Musk

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Elon Musk hopes to build a city on Mars that will be self-sustaining by the 2050s.

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“There is a pretty good chance we end up with a universal basic income, or something like that, due to automation.”

– Elon Musk
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neque. ut in et, massa felis tristique efficitur. libero.