The Sense Beyond Common Sense

it is often said

common sense is not very common implying

that having

good common sense is an intellectual

privilege

we also think common sense qualifies as

to

analyze and comment on anything

when a survey was conducted in australia

on the public perception

of climate change almost one third of

the respondents

commended that they don’t think climate

change is happening

and they attributed the reason for their

conclusion

on common sense it’s just common sense

that’s what they said

being a person who has been learning

doing and teaching science

i would say that you need a sense beyond

common sense to understand science

i would even argue that common sense is

a hurdle for understanding certain

things

let’s have a look at the famous

experiment of the following

objects originally done by galileo

galilei

take two water bottles one of them is

empty

and the other one is filled if you allow

them to

fall from rest from the same height

which one of them would hit the ground

at first

just think about it if you remember your

school lessons you would say

that both of them would hit the ground

at the same time

but just introspect and ask your common

sense

what it says to you about the outcome of

this experiment

if you ask me i still feel amused to see

the result of

this experiment when it is performed in

real

simply because it doesn’t appeal to my

common sense

the problem is we are thinking in terms

of mental images

when we think about something we try to

visualize it in our mind

that’s part of our common sense we think

and talk about things

which we can feel inside but there are

many serious issues with visualizing

things in our mind that way

one of the issues is regarding the

inherent limitation

in assessing the magnitude of physical

quantities

beyond a particular range we are

used to the magnitude of physical

quantities in a particular range

if it is smaller or larger than those

limits

we tend to lose the feel for this

consider the example of weight we all

have a certain feel about the weight or

heaviness

of objects when i ask you what is the

weight of an orange you have a feel

inside

how much an orange would be but i want

you to note the difference between

giving a number and

feeling it inside you won’t be able to

say exactly how many grams an orange

would be

but you have a feel inside the same way

you have a feel on how would

a 20 liter can of water would weigh and

you can also have

a feel of the comparison between the

weight difference between an

orange and the can of water but do you

have a feel

about the weight of a bacterium well i

can give you the numbers if you want

a bacterial cell is typically around one

trillionth of a gram in weight

but can you feed it inside a bacterial

cell is

hundreds of times heavier compared to a

virus but can you feel the difference

between

the masses of a virus and the bacterium

say i tell you a truck is 20 tons in

weight can you

feel how that heaviness is the same way

you felt the heaviness

of an orange now consider numbers if i

say there are

5 apples to your left side and 3 apples

to your right side

you know a feel of the difference

between these two numbers

right but if i say there are thousand

apples on one side and two thousand

apples on another side

can you have the feel of that numbers

both of them are essentially a heap of

apples to you right now

maybe one heap is bigger than the other

but you simply lost the feel for that

number

what about time all of you have a feel

about how much time has passed since you

started listening to the speech

a few minutes with some reasonable

margin of error

but a honey bee flutters its wings 200

times a second

do you have a feel about the sharpness

of the time interval between two

successive flaps of its wings

what about the difference between two

thousand years and three thousand years

you know the difference between the

numbers two thousand and three thousand

when they are

written or told but i want you to

introspect

about the difference in the time periods

of two thousand and three thousand years

aren’t we just comparing the visual

appearance of these numbers when they

are written

or the auditory feel of these numbers

when they are told

do we actually have the feel of the

magnitude of the time involved

to clarify this let me show you this

what comes to your mind when i say 0

is it this if it is just think about it

a little bit further

is this 0 or is this really

a symbol that represents the idea of

zero

this may invoke the concept of zero in

your mind but this is not

zero by itself what about the word me

nothing if i ask you to imagine nothing

whatever comes to your mind is not

nothing

because if something comes to your mind

it is something rather than nothing

by now if you are feeling that i am

playing with words really i am not just

think about it

another serious issue is regarding the

misconception

about the absoluteness of certain

quantities

time for example is commonly taken as an

absolute quantity

it’s always taken for granted that time

flows equally for all

when i say 10 seconds you understand it

there is no ambiguity involved

but it’s based on the assumption that

the duration of one second for me

is exactly equal to the one second of

yours

or in other words we assume that your

cloak and my clock

tick at the same rate but it has been

proven many times

with precision that it is not the case

if you compare

a stationary cloak with a moving clock

a moving clock will appear to be slower

compared to a stationary clock of course

the difference may be negligibly small

for ordinary relative speeds of motion

but negligible

is not zero and the difference is there

it’s not just about

time intervals for a moving observer

length and mass are also relative

it’s one of the key implications of the

theory of relativity in physics

see it means things which we can have a

feel for

are actually relative and not absolute

but in nature there are certain

quantities that does not depend on

observer but gives you the same result

whenever they are measured such

quantities are called

natural constants or fundamental

constants the speed of light in vacuum

may be the most common example all

measurements of the speed of light will

give you the same result

irrespective of whether the observer is

stationary

or moving with light or moving against

light

of course it’s quite counterintuitive

how can something

appear to have the same speed when you

are moving

at it or when you are moving with it

there are many such natural constants

like gravitational constants planck’s

constant etc

which are absolute and will give you the

same value whenever they are measured

wherever they are measured and whoever

measures it most of them

have dimensions that cannot be

visualized or felt

in our mind you may be able to visualize

heaviness

length distance time period

brightness etc but how would you

visualize a quantity

that is force multiplied by the square

of distance

and then divided by the square of time

what kind of a quantity that would be

well that is the dimension of

gravitational constant which is a

fundamental constant that will give you

absolute value for its measurement see

some things which we think

are absolute are really relative and

some other things which are actually

absolute

are beyond the grasp of our mind i hope

you understand the point i’m trying to

try

to add to this let’s also have a look at

our available sources of information

our primary sense is vision where we

receive information about our

surroundings through light

light is essentially an electromagnetic

wave which is nothing but a parade of

oscillating

electric and magnetic fields depending

on the rate of this oscillation called

the frequency

electromagnetic waves vary in nature

from a wide spectrum of frequencies from

high frequency gamma rays to low

frequency

radio waves our eyes can sense

only a tiny band of frequencies which

are around a few hundred terahertz

and we call those frequencies by the

name visible light

the same is the case with sound sound

is essentially a pressure verb created

by

vibration of objects from a wide

possibilities of

frequencies of vibration our ears can

detect

only a particular band of frequencies

from 20 hertz to 20

000 hertz if it is not in this range

you don’t hear anything even if there is

sound

the moral of the story is the nature

doesn’t

care about how human brain thinks

it has its own ways to work while

discussing quantum physics theory of

relativity etc scientists often say that

these ideas do not agree with our common

sense

even i say it in my classrooms

but there is one important point to be

added here

is it mandatory that these mechanisms of

nature

should agree with our common sense who

are we

homo sapiens are one among the millions

or billions of species of organisms

living on the surface of this planet

we think homo sapiens are special simply

because we are the homo sapiens

we evolved a few hundred thousand years

ago on earth

with bodily adaptations suitable for

surviving

in the circumstances of that time

our circumstances have changed

drastically during these years

but our brains haven’t it was too small

a time period for biological evolution

to make

considerable changes on our brains or in

other words

a cavemen of the paleolithic age where

as

intelligent as we are today or we are

only as intelligent as a caveman

from the paleolithic age whichever way

you want to put it of course

we have excellent cognitive capacities

compared to other species of

living beings but they are not custom

made to comprehend everything

that’s what calls for science with

science we have devised

tools to transcend our senses methods to

circumvent the limitations of our own

common sense

so that we can unravel the secrets of

this universe

to see what the sense of science has

done to humanity

let’s have a look at history as we said

history of homo sapiens extends around

200 000 years back

but let us stick on to the history of

human civilizations

invention of agriculture is considered

to be the beginning of human

civilizations

because that was what made us capable of

settling down

and building up large societies

evidences tell us that

agriculture is not more than 10 000

years old

but even that number is too large for

our brains to visualize

as we have discussed earlier therefore

let us shrink this history of 10 000

years

to one single year that means in this

calendar

humans invented agriculture on the dawn

of a january 1st

and the present day is close to the

midnight of december 31st

remember in this special calendar every

day is equal to

27 years in actual history now let us

try to place some significant inventions

or discoveries

that change the shape of humanity in

this calendar

how would you expect them to look like

this is it

see how crowded those discoveries or

inventions are

in the last fortnight of this calendar

electricity

automobiles computers x-rays even the

seventh

planet in the solar system almost every

technology which we think are

fundamental to humanity now

came to existence only in the last

minute in this drama

now if you look for a reason behind this

crowding of events the answer lies in

the history of science

we are able to accomplish feats after

the discovery of the method of science

that discovery didn’t happen on a single

day but was in fact a collective

realization

from a long history in that sense i

would say that the best

discovery of humans was the best method

to find out truths

which we call the method of science

today so

i vote for the sense of science over

common sense

thank you