Library Simple Science
Click to enlarge Click to watch video Click to follow link
Science without assumptions
Science without assumptions

“Any assumption can, in principle, be criticized. And that anybody may do so constitutes scientific objectivity.”

―Sir Karl Raimund Popper

Ever since our school days, we have solved problems where assumptions were known to have been made, that is, the conditions under which a particular experiment takes place. Temperature, pressure, humidity and other factors are often given as such conditions. Conditions can change, and the solution to the task set changes together with them.

In most tasks, so-called standard or normal conditions are indicated. Despite the fact that such conditions may vary depending on the discipline being studied, 'standard' is nevertheless taken to mean temperature corresponding to room temperature (20 °C) and pressure close to atmospheric, sometimes simply 100 kPa.

It is with such input data that most research has been performed around the world.

But what happens if the standard conditions change? Can we posit how such changes will affect the properties of matter at different levels of its organisation? That is, at the level of the organism, individual systems of organs, tissues, cells, and individual biological molecules such as proteins and inorganic substances.

Much of this topic is well known to all of us simply from life experience. For example, when we come across the figure 36.6°C, we immediately understand the level of organisation in question. We also know first-hand what happens if this number changes by even half a degree. If the temperature changes by 4-5 degrees, the body may not survive such a change.

Any biological system is a very highly sensitive and complex object. It is not easy to foresee what will happen if a biological object is put under certain extreme conditions. We know this from personal experience, whereas the specialist scientific community knows this from applying statistical methods to a correctly formulated scientific problem. Modern biomedical science uses precisely such essential methodological instruments.

In physical chemistry, a different methodological approach prevails. It is derived from the fundamental law which the experimental model of interest to us follows. However, this law ceases to describe the real state of things when a model is placed under new conditions. Thus, the fundamental principles of natural sciences are constantly refined.

A striking example of such refinement made in recent years is a work entitled “Unexpected stable stoichiometries of sodium chlorides” published in the journal Science (Oganov et al., 2013) and on the website of the Moscow Institute of Physics and Technology (MIPT). The paper presents data indicating that at ultra-high pressure, stable structures containing atoms of Na and Cl in a ratio different from the usual 1:1 ratio form, namely NaCl3, NaCl7, Na3Cl2, , Na2Cl and Na3Cl. From the point of view of classical chemistry, these structures seem at least unexpected.

Science without assumptions Crystal lattice of new sodium-chlorine compounds. Source: mariecuriesnews.wordpress.com news portal

“The rules of chemistry are not like mathematical theorems, which cannot be broken,” says one of the authors of the article, Artem Oganov. "The rules of chemistry can be broken, because impossible only means 'softly' impossible! You just need to find conditions where these rules no longer hold."

Artem Romaevich Oganov

Artem Romaevich Oganov is a professor at the University of New York, has 120 publications and chapters in scientific journals, and runs three laboratories: in the United States (New York), China (NPU) and Russia (MIPT). Source: MIPT official website.

The above example is not by any means the only one. Thus, 'superionic ice', which is expected to form at extremely high pressures and temperatures, is well known within the physics community. This model describes a new state of water, in which it is no longer characterised by the presence of individual molecules that interact with each other through hydrogen bonds, but is more like a lattice of oxygen atoms, inside which hydrogen ions flow. This news was published in Science in 2018.

Thus, it is quite difficult to find completely inviolable laws in nature. The fundamental laws formulated by man are followed only under certain assumptions. It is often extremely difficult to step outside of such assumptions, but when this happens we have to admit that it is impossible to fit lawless nature into any framework.