Question

What lies behind the phenomenal progress of physics in the last few centuries?

Answer 1

• Great progress usually accompanies changes in our basic perceptions.
• First, it was realised that for scientific progress, only qualitative thinking, though no doubt important, is not enough.
• Quantitative measurement is central to the growth of science, especially physics because the laws of nature happen to be expressible inprecise mathematical equations.
• The second most important insight was that the basic laws of physics are universal — the same laws apply in widely different contexts. Lastly, the strategy of approximation turned out to be very successful. 
• Most observed phenomena in daily life are rather complicated manifestations of the basic laws.
• Scientists recognised the importance of extracting the essential features of a phenomenon from its less significant aspects.
• It is not practical to take into account all the complexities of a phenomenon in one go.
• A good strategy is to focus first on the essential features, discover the basic principles and then introduce corrections to build a more refined theory of the phenomenon.
• For example, a stone and a feather dropped from the same height do not reach the ground at the same time.
• The reason is that the essential aspect of the phenomenon, namely freefall under gravity, is complicated by the presence of air resistance.
• To get the law of freefall under gravity, it is better to create a situation wherein the air resistance is negligible.
• We can, for example, let the stone and the feather fall through a long evacuated tube. In that case, the two objects will fall almost at the same rate, giving the basic law that acceleration due to gravity is independent of the mass of the object. With the basic law thus found, we can go back to the feather, introduce corrections due to air resistance, modify the existing theory and try to build a more realistic

[Source: https://www.scribd.com/doc/14118870/NCERT-Book-Physics-XI-Part-I Page No 7]