Science is either physics or stamp collecting?

What is science? In one simple sentence, science is the study of nature. However, different sciences like: astronomy, chemistry, biology, geology, etc. have different approaches to do so. Thus, not all sciences are equal.

The quote 'All science is either physics or stamp collecting' by New Zealand physicist Ernest Rutherford perfectly reflects that inequality. According to him, physics is the king of sciences because it is fundamental to all other fields of study.

But why exactly did Rutherford think in that manner? Despite himself being the recipient of Nobel Prize in chemistry, what made him consider physics the most noble of sciences?

The answer lies in stamp collecting - a hobby in which people collect and classify stamps as objects of interest or value.

Stamps are available in many varieties - big and small, square and round, stamps with famous human faces, stamps with animals and birds, stamps commemorating anniversaries, etc.

 Rutherford's stamp 

Similarly, some branches of science, such as zoology or botany for example, are mostly concerned with collection and classification of species - animals and plants, respectively.

Although this would be dumbing down those sciences but that is more or less the purpose, isn't it? In other words, those sciences are not fundamental sciences and their scope is limited only to Earth.

Physics, according to Rutherford, is the only science that has an elaborate structure consisting of observation, experiment and mathematics. Physics captures our imagination from mysterious atoms to supermassive galaxies. It truly is the universal embodiment of the scientific method.

By this definition, the science which is closest to physics is astronomy. You observe and measure the effects of, say a black hole on its surroundings, with the help of a telescope and basic knowledge of mathematics. In this way, like engineering, astronomy is an application of physics and mathematics.

Chemistry is a unique science because it has the 2nd most direct impact on day to day life after physics. The objects we use, such as plastic, glass, steel, etc. are all obtained by chemical processes.

Our body is a chemical engine and the food we eat are organic molecules. But just like biology, there is a lot of nomenclature and classification rules in chemistry to deal with. Chemistry is also not universally the same, like on different planets, but the laws of physics governing those chemistries are the same.

Likewise, sciences like computer science and psychology are neither fundamental nor universal. They are narrowed specializations and are heavily dependent on logic, mathematics and observation.

All the sciences, however, must ultimately be experimental because that is how they progress. That is how the hypotheses are tested and verified and accepted. So it is worth pointing out that no amount of belief can make something true. Sciences keep evolving with time as new evidence is uncovered.

Finally, it is equally important to mention that the statement "all science is either physics or stamp collecting" had more truth to it back in Rutherford’s time than today.

As you know, for example: With Darwin's theory of evolution, biological sciences have too become observational rather than just being classification sciences.

So, over time, sciences evolve and become more and more physics-like. They are no longer merely observe and classify but start using mathematical models. Still, Rutherford's point is intact, physics will be the king of sciences.