Wednesday, December 14, 2005

Can I believe my eyes?

The world around me is beautiful. When I look around I see lush green meadows, clear blue sky, an assortment of flora and fauna, garish setting sun, azure depths of the ocean and I end up thanking my eyes for letting me see and enjoy this spectacular world around me, in all its glory. Eyes, in deed are a wonderful pair of sense organs. And I can’t do anything but end up philosophizing them.

Eyes, how many mega pixels are they?
Well, I am not talking about the latest digital cameras whose manufactures babble about the maximum resolution they can give. If we think about our eyes a bit more and refresh our high school biology lessons, the retina on which the eye-lens refracts light rays is made up of two kinds of photoreceptor cells called rods (enable black and white vision) and cones (enable color vision) which convert those light rays into electrical impulses, through an electrochemical reaction, which is processed by our brain to make us ‘see’. Roughly 125 million of them are intermingled non-uniformly over the retina, which means that the resolution of our eye is confined to the number of rods and cones we have, which is nothing but 125 Mega Pixels! Yes, if we had the ability to zoom images as we do using normal picture viewer software, after some limit, we will also see objects pixilated!

Do we see ‘everything’?
Humans can ‘see’ radiations of wavelength 390 to 780 nanometers (visible light) using his eye which form only a small part of the entire electromagnetic spectrum. We can’t see other radiations. We see an object when light rays fall on that object and the reflection is captured by our eyes. What if a particular object reflects only radiations of wavelength other than that of light? Duh! Then we won't be able to see that object. Thus there is a whole different world around us which we can’t see. A world that is quite different than what we can probably imagine of.

Does everyone see the same color?
Suppose a person sees a rose and identifies it as a red rose. Another person who is seeing the same rose is also identifying it as a red rose. But are we sure both the people identify it to have the same color? Ok let me explain it. Suppose a child who is seeing a yellow rose (color is yellow, called as yellow) ‘sees’ its color as a red. So for him that particular color would be yellow (which actually is red as seen by him) and is called as yellow. Which means, whenever he sees a yellow rose, even though he identifies it as a yellow rose having yellow color, actually he would be seeing it in red color. Physicians call it an extreme case of color blindness but I should say that people see the same object in different colors!

Can we believe our eyes?
Ultimately every single object in this universe is made up of atoms. An atom consists of a small nucleus at its centre and sub-atomic, wave-like particles called electrons spinning around it. The ratio of the sizes of a typical atom to its nucleus is about 100,000:1. For solids, this ratio comes down a bit; nevertheless, almost the same. But on an average, the nucleus forms a very small part of the whole atom. That is 99.99 percent of an atom doesn’t consist of anything. It is pure vacuum. Atoms form molecules and in turn form different objects we see around us. That means that when we see an object, say a pen, we are actually seeing something which is made up of particles which are 99.99 percent vacuum. Or we are seeing a pen which is actually 99.99 percent vacuum. Still we see it as a complete pen. Our eyes add the non existing 99.99 percent! And we believe our eyes for making us see something which is not there at all.

Thus there are a lot of limitations to the human eye. It doesn’t show us all the things, shows us something which is not there or shows us something which is 99.99 percent nothing, gives us a totally wrong picture of our surroundings. But still, in a way, all that is shown to us by our eyes are enough and more for us to exist; to enjoy and appreciate the wonders created by the nature. And we know how miserable the life of a blind is. Eyes are precious in deed. Nonetheless, for a subtle conclusion; next time when you see a friend of yours, just think out how he/she would look like in reality as compared to what ‘you’ see him/her using your eyes. Looks are deceptive, when you have eyes like this. :-))


>|' ; '| said...

heh! i remember the thing abt us seeing something that is 99.9% vacuum. the fact that the colors i see might not be the same for all even though we all call them by the same names, is highly intriguing. great post!

Geo said...

Incredible... last week I had a discussion with a friend of mine abt something similar....

"Your red and my red may be different"

susubala said...

If our heart is beautiful and clear in our thoughts and eveything seems to be beautiful in this world !!!

Nice post and I liked it.

Jithu said...

> poison
yeah! donno whether there is any explanation for that. one posible explanation can be this. light rays (which are particle in nature according to Max Plank's Quantum theory) get reflected by the electrons spinning around the atom; our eyes capture those reflected rays and make us see that object. but the particle nature of light itself is in question. light photons are so small that when the atom density is low (the atom size to nucleus ratio is high) light simply penetrates thru the atom; wont get reflected, making that object invisible. this is true when we consider gaseous atoms where the atom size to nucleus ratio is high and hence we cant see gases and for solids, this ratio is low and hence light can't simply pass thru it, gets reflected and we can see them.

on a different note, light may get diffused to its constitute colors on its collision with the electrons before getting reflected, so that instead of seeing the object as white, we see the object in a particular color. this again depends on partial absorbtion of radiations within light spectrum by the atom, due to which some colors may be absorbed and some may be reflected and we see that object as the sum of colors of reflected light.

> geo
that is an interesting phenomenon. no one can explain what gradient of red he/she is seeing coz right from the day he is seeing that particular gradient of red, he identifies it as "the red" as others and henceforth he/she sees it as the same "the red". :-) hope its not confusing. i am not able to put it thru words :-(

> susubala
ha ha.. thts the ultimate reality :-) beauty lies not in the object, but in the eyes of the beholder. coz everyone sees the same object differently :-)) hey thnx and welcome to my blog :-)

Invincible said...

when Darwin analysed our retina, he too admiited how something as complex as human retina can be thought of evolved from something as primitive as amoeba :) n how his own evolution theory can acct for such a complex organ.

145 MP !! with the flexibility of moving focus in a nanosecond from an object at 15 cm to one at 15K KM.

we see only a limited part of the radiation spectrum (we dont see ultra-v/ infra-r , x-rays, etc) so yes, we cant see the universe wth these eyes. No wonder scientist use the other frequecies n radars to explore universe.

ur eg of colorblindness was completely shattering! God save such ppl.

The solids have dense molecular structure, apart from low atom size to nucleus ratio hence they r not see thru like some-liquids/gases and they absorb n reflect radiation more.

Wonderful post Jithu. Touched so many planes :)

divya said...

im reminded of my physics n biology classes!
need to read it again.......wen its not 3 in the morn before an exam

Keshi said...

Eyes may not catch everything one should...but a heart does :) I like wut Sumi said too.

See beyond what the naked eye can see...just feel.


Jithu said...

> invincible
hey thnx man for that info abt Darwin. tht is so very true. yeah in fact infrared as well as ultraviolet imagery are used a lot by scientists to explore the universe, which make them see things which cant be perceived by human eye. well that was an extreme case of color blindness. in normal cases, ppl cant identify the gradients of a particular color.

> divya
:-) all the best for ur exams...

> keshi
yeah even i liked sumi's reply.. thats were all these things boil down to :-)

Ardra said...

interesting read jithu! the comments too-
Jithu, I'm unable to readu'r malayalam blog page- I tried downloading the font- all that came was some wierd msg repeated umpteen times...could u help me please?

Divya said...

now abt the post as i said earlier it did remind me of physics n bio from school....but then it is a wonderful post. i mean it did make me wonder and not just about the physics behind it (which seems to be pretty well explained here by u n others in the comments) but about the ease with which we take our sight (as imperfect as it might sound) to be granted......
some lovely comments here too....
i guess beauty does lie in the eye of the beholder....
Bye n TC,

Pradeep said...

Enjoyed reading it, more so because I have a science background. So, there's nothing absolute in the world.

Jithu said...

> ardra
hey thank you very much :-)

in order to read the malayalam blog, if u r using internet explorer and had installed the font mentioned in the site,
1. right click > encoding > (more) > unicode (utf-8)

i guess this shud, else,
2. tools menu > internet options > general tab > languages button > add > malayalam (ml)
3. tools menu > internet options > general tab > fonts button > select language script as malayalam > select anjali old lipi from the webpagefont box.

still u find any problems, feel free to ping me at i'll b online in yahoo messenger. may b u can also start writing in malayalam. :-)

> divya
hey thank you very much! :-) "chinthichaaloru anthavumilla chinthichillenkil oru kunthavumilla ennalle" :-))

> pradeep
thnx man! yeah there is nothing absolute in this world. ellam maaya aanu :-))

~*. D E E P A .* ~ said...

Hi ...

Thanx for stopping by .....

What we see depends on our perception.
When we are kids , everything in black or white .. as we grow up , we see shades of grey too

~*. D E E P A .* ~ said...

and about colours , even men and women intepret colours differently ...

for e.g. ask a man what ' plum ' or ' mauve ' is .. he wont have any idea ..

or the difference between ' blue and red ' and ' red and blue ' ...

women thrive on these details :)

silverine said...

I dont think eyes are deceptive. Just co relate what you see to what you touch and it is ample proof that we see things as they are.All solid objects are dense clusters of atoms which gives it a definite shape and mass. Our eyes thus are able to define these objects for us.

venus said...

I have wondered this many times when I was studying physics! And addition to my wonder is: how do we feel touch, we are touching 99.99% vacuum, and how do we still feel solid/liquid/gas? when even the atimic particles themselves are like string waves, and chemical bonds are also sharing these waves?

venus said...

btw, I've started reading Five point someone, and I just love it :) I wanted to finish it at one sitting, but had to consider going to work next day..

Jithu said...

> deepa
hey thts something new to me. for kids everything is black and white? cant quite remember anything from my childhood memories.. :-(

well well well, the plum & mauve thingy, i guess its due to some other reasons :p and u know that.. :-))

> silverine
well, lemme try to comment on that. tell me if u dont subscribe to it. when we go to the molecular level, every object appears like something made out of a loose 3D wireframe with atoms/molecules on the joints and large free spaces in btn the joints (the structure due to molecular/atomic bonding). but then our hand is so big compared to that that it cant pass thru those small voids. so still that 99.99 percent vacuum thingy stands valid (considering the object as a whole and the spaces in btn the atoms) but just that its at such a microscopic level that we happen to feel it as a whole. shape of an object is independent of its density.. hope it answered u.. but yeah as u said, we feel an object the same way as we see it because this 99.99 percent vacuum thing is not something external to the object. its also a part of the object.

> venus
we feel touch when some pressure or force gets applied on the sensory nerves on our body. when we touch an object we are actually applying a small force on that object. now that object is made up of atoms/molecules which have aligned to one another. that alignment or bonding itself has a force associated with it. so when we touch an object the force we apply is opposed by this force of attraction btn the atoms/molecules in that object and our nerve cells sense this opposite force and we get the feeling of touch. pretty complicated process huh :-) and depending on the amount of this opposing force we feel the object as hard/soft (i'm not saying solid/liquid/gas because if we close our eyes and touch a soft solid and a hard liquid we FEEL the same. the only difference is that in the case of a liquid due to its state, it touches ur entire finger where as a solid touches on the tip of ur finger). in the case of a liquid part of the force we apply wud be absorbed by the liquid and its used to deform the liquid (eg. when we dip our finger in water, the water level rises) and we feel only the remaining force which wud be less compared to touching a solid with the same force. so ultimately, our hand doesnt know that its touching a solid/liquid or a gas. we identify an object as a liquid coz
1. a liquid sticks to ur finger,
2. ur finger penetrates thru the liquid,
3. liquids are soft in general
4. u see the object.
all these make u feel that u r touching a liquid.. i think i shud stop here :-))

yeah FPS is a great book. i'm sure u'll enjoy it :-)

the Monk said...

yeah, they really are something...

Thulasi said...

jo dikhayi detha hey wo sach nahi hey
jo nahi dikhayi detha hey woh bhi sach nahi hey
sach kya hey?
sab maya hey !

( ഒന്നും മനസ്സിലായില്ല,ഇത്തു ഒരു പുലി തന്നെ എന്നതൊഴിച്ച്‌ :) )

tangy said...

y so much abt eyes???

aria said...

Wow! Now tht was something - really nice read .. n lots to learn frm the blog n also frm the comments.

Jithu said...

> the monk

> thulasi
hey i am sorry man.. :-) havent posted something serious for a while.. thts why i posted this.

> tangy
well nothing much. arent eyes so wonderful :-)

> aria
hey thnk you very much.. :-)

niki yokota said...

hi jithu!!
this is very interesting post. thanks sooo much!!(^o^;;;
i have prob with pink & orange sometimes.
when i think something is 'pink', my frens say that is 'orange'.
ohhhh noooooo~ i cant believe our eye sights

Mirage said... facts! I'm suddenly 'seeing' things in a diff light! ;)

Jithu said...

> niki
thnx niki. oh really? yeah it happened with some of my friends too.. :-)

> mirage
ha ha. i think my post served its purpose then :-)

illusion said...

Eyes..eyes baby!!! wonder bollywood had so many movies and songs...devoted to the title..aankhein,akhiyaan, nazar, al....
The Eye-candy....thanks a lot for your lines on my post...happy postin!!!

~*. D E E P A .* ~ said...

ting-tong !!

Praveen said...

Very informative :)

Habibi said...

I've had the conversation about colour blindness many times. Let me explain. My brother-in-law is color blind and he sees the sky pink. He knows he is color blind so if you ask about something he's seen before he'd answer "propperly" (as per what we, non colour blinds, see), though, with new situations, he would answer "different".
My thought is: What if what is truly happening is that he is seeing the sky as it is and we are the colour blind ones?
Is like a friend who esquizofrenic (medicated and not deeply esquizofrenic) and when she had the atacks she saw things that "weren't" happening or things that we normally can't realise (many, many things at the same time). I wonder, if when her brain has more of that chemical element than it is used to, she is realising of more things than normally, perhaps she is seeing life as it "rally" IS, i.e. perhaps she should not medicate and should "see life as it is", if she can cope with it.
The same with colour blindness; perhaps both my friend and my brother in law are seeing the REAL life and we are missing it.
Who knows!

Jithu said...

> illusion
ha ha.. yes mite be a reason.. hey u write really well..

> deepa
hmm.. :-)

> praveen
thnx man..

> habibi
hey welcome to my blog.. that is an interesting example of color blindness that u got here.. and the last sentence, starting a new train of thoughts.. everything is relative rt.. who knows we ourselves are seeing things correctly :-)

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