∆ Illusion of perception.

Profound Finger tapping.



Unlike Einstein’s thought experiments this is an actual exercise that may demonstrate something extremely profound that is both obvious and completely and utterly hidden to all people.


Start by tapping a hard surface with one of your fingernails, a table top is ideal. If you’re in a place where it won’t annoy anyone else keep doing it for quite a few repetitions and examine carefully everything that seems to be happening. Tap tap tap, you feel a sensation through your fingernail and in your finger tip. Tap tap tap you hear the sound of the nail hitting the table and you see what’s happening. You can see the finger moving, hitting the table, lifting and falling again. You can also see the tendons in the back of your hand operating to ‘carryout’ (an interesting word) your commands.


Now let’s look at each of these aspects in more detail. You hear the tapping sound so what do you actually hear? As it hits the table, your nail and the table both vibrate and by vibrating they vibrate all the air around themselves. These vibrations or pressure waves aren’t very big but they do happen and they spread out from the place where nail and finger meet in much the same way you actually see ripples of  water spread on a pond from the point where a stone has just hit the water.


But note here that you don’t actually hear the sound where your nail hits the table you hear the sound that reaches your ear. This is the same as realising that when you are paddling and someone throws a stone in the water you feel the water that is actually rippling at your ankles. And this is a slightly different thing. In fact if you move your ear closer to the tapping you will of course hear it get louder and hear more detail in the sound. If you move further away you hear less of the noise, less volume and less detail the main point is that you hear the sound that actually reaches your ear. And not the actual sound at the point where it is made.

More accurately you hear the sound that travels down your ear canals and hits the delicate membrane they protect called the eardrum. You can prove this simply by covering your ears with your hands. Your hands stop most of the sounds reaching your ear drums and so you don’t hear the sound. So the sound you hear is in your head. Not just in your head in the sense your eardrums are in your head but the sound you perceive. The sound you like or hate, recognise or don’t is in your mind, in your head. Not ‘out there’ where the finger meets the table.


What do you see? Well you see your finger tapping the table of course. However the way sound and light work and travel are similar in some important ways and in actual fact you don’t exactly see your finger or the table. You see the light coming off your finger and the light coming off the table! So what? It’s the same thing. No. Its not its very important to realise that what you see is the light coming off the objects, making it through the lens in your eye and hitting the collection of light sensitive ‘cells’ at the back of your eye that we call the ‘retina’.

If you move your eye closer to the scene it will get bigger and brighter. The brightness aspect you won’t usually notice because there is usually so much other light around confusing things. If you imagine looking at a light bulb in an otherwise dark cave from 10 metres away it might be quite bearable but if you walked closer and closer until you were just a few centimetres away, well then you’d see how it got brighter.

Bigger? Yes. The image gets bigger. But we know that typically ‘things’ don’t actually get bigger just because we get near to them so we adapt naturally, the object, finger, table stay the same size but the image formed at the back of your eye is bigger. Again you can prove that it’s not the objects that you see by putting your other hand in front of the tapping finger. This hand will block the light and instead you will see the light reflected off your other hand (if there is some light available to light it up). So? So what you actually see is in your head. In your head in the sense that you actually ‘see’ the pattern of light formed on your retina and more so, in your head in the sense that the finger you recognise or the table you don’t recognise must be in your mind for you to know whether you have seen them before or not.


Ok nearly there, what do you actually feel, what about the sensation, the nail hits the table, you don’t feel the table its on its own but you do feel the little ‘shock’ as nail meets table, you feel it through your nail bed, up your finger, the back of your hand and then it fades out. But like the sound and the light what you must actually feel is that stuff that actually reaches your mind. Not the signals that travel up through your nerves but those signals where they actually reach your brain.


So, what you hear is in your head. What you see is in your head and what you feel is in your head. Tap your finger once again. Look at, listen to and feel the exact point where the finger meets the table. The exact spot, and you might realise that that actual spot where it ‘looks, sounds, and feels like’ your finger is touching and tapping the table must actually be a ‘re-presentation’ of that event ‘in your head’.


The table, the finger the tapping etc all really exist, but you and i naturally only ever perceive a re-presentation of the world. There is nothing wrong with this, and if you think about it there is no other way nature could really make it happen.


The point here is just to highlight a ‘persistent illusion or misunderstanding’ that will never reveal itself by chance, but can only be realised through some careful thought - which also gives us an insight to the possibility that Time too may be an illusion or misunderstanding that presents itself only with careful thought.