Page 85 - For Men of Understanding

A robot, no matter
how advanced, can
never possess
the features
of a real
hand.

We even do not bother to think about these.
The reason is that the human hand is designed to per-
form all these acts simultaneously. The hand is created
together with all its functions and all its related structures con-
currently.
All the fingers in the hand are the appropriate length and position, and
proportionate to each other. For instance, the strength of a fist formed with a
hand having a normal thumb is greater than that formed with a hand having a
shorter thumb, because with its pre-determined appropriate length, the thumb
covers other fingers and helps augment their power by supporting them.
There are many small details in the structure of the hand: for instance, it
has smaller structures besides the muscles and nerves. The nails at the tip of
the fingers are by no means trivial accessories. When we try to pick a needle
from the floor, we use our nails as well as our fingers. The rough surface com-
prising our fingertips and nails helps us in picking up small objects. Last but
not least, nails play a big role in the regulation of the minute pressure fingers
have to exert on the object they hold.
Another distinctive feature of the hand is that it does not get tired.
The worlds of medicine and science spend a considerable effort on making
an artificial copy of the hand. The robotic hands so far manufactured have the
same performance as human hands in terms of power, yet it is hard to say the
same thing for sensitivity of touch, perfect manoeuvrability, and the ability to
do diverse jobs.
Many scientists agree that no robot hand can be made having the complete
functions of the hand. Engineer Hans J. Schneebeli, who has designed the
robotic hand known as "The Karlsruhe Hand", stated that the more he worked
on robotic hands, the more he admired the human hand. He added that they
still need a lot of time to make possible even a certain number of the jobs
accomplished by a human hand.
The hand usually functions in co-ordination with the eye. The signals reach-
ing the eye are transmitted to the brain, and the hand moves according to the
command given by the brain. These, of course, are completed in a very short
time and without making us spend a special effort to do them. Robotic hands,
on the other hand, can only rely either on sight or touch. Different commands

The Human Being 83