• # Understanding sizes on a relative basis

One thing which is taught to the children in their primary classes is about the size of an object. Some objects are small in size while some are big. The children learn these things quickly and start differentiating items based on their sizes. They start understanding what is a small-sized item and what is a big-sized item.

Let us try to understand the sizes of the bodies or material around us in a more comprehensive fashion. If we go deep into the subject then we would find that the range of sizes is mind-boggling and some particles or entities have very small sizes which we can't see with the naked eye. For example, the size of bacteria and viruses is so small that we can only see them under a microscope. On the other hand, the size of the heavenly bodies and the size of the universe is so big that we can not imagine those figures. The stars are so far from us but they are huge and emit light that we can see even with our naked eyes.

Let me make some interesting comparisons of sizes to get a feel of them.
Every material has molecules in it which are composed of atoms. The size of the atoms is so small that in one-centimeter length approximately one hundred million atoms can accommodate. So one centimeter is a very big size compared to the size of an atom.

Now let us see the size of Earth. It is a massive spherical heavenly body having a diameter of 12700 kilometers. It is very big but if we see the size of the Sun then we find that Sun's diameter is eleven lakh times bigger than Earth's. The size of the solar system is much bigger and then there are huge galaxies inside one of which (Milky way) our solar system resides.

So sizes can be understood only on a relative basis. Have you observed the sizes in that fashion?
• The author is right in explaining a thing to a children, that too in the primary level as the same is very important base to them. Only some teachers are nowadays giving sub stories and examples while explaining the subject topic. In those days what we have been taught in schools are even in my 65th year remembered. If the object of the story or of the example seen by us immediately we remember the subject topic as taught in the school.

• The size of an object can be mentioned in real figures as we can measure them using some equipment. There are different equipment of different sizes. When we mention the sizes we should mention the units also.
But comparison will come when there is a minimum of two items. One will be big and the other will be small. But the bigger one may become small when compared with a still bigger item. So these sizes are relative.
As a matter of fact, even in bacteria also which we can't see with the naked eye. there are differences in sizes. Similarly, atoms of all elements are also not equal. Atomic weight and volume will be different from one to another element.

drrao
always confident