It is not really relevant if the iconic scene of the man from Lincolnshire and the forbidden fruit happened or not. However, one thing is clear, the apple didn’t know physics. Yet today, apples, oranges, pineapples, and even “the tree in the forest that made the loud noise that we couldn’t hear when it fell” know physics. If so, how comes that they obey Newton’s laws? The answer is simple – believe or not- they don’t. In fact, they don’t need to. What we call gravitational field is there and it has been there even before Newton. Therefore, apples just fall.
Science provides description for phenomena that we see everyday. Those descriptions are, usually, written in a very versatile and powerful language known as Mathematics. Yes, Math is a language. Math is not just a bunch of number intertwined in a complex way. No, Math is a very clear language for the description of physical “laws”, biological “laws”, chemical “law”, and many others. An intriguing feature of this language is the power of prediction. Yes! in many cases, this language allows determining in advance, with great likelyhood, what it is going to happens. For instance, the classical high school’s exercise of “the cannonball fired with X acceleration at Y angle, etc, etc, etc”. By knowing the initial conditions, we can tell where is the cannonball is going to land. The ability of prediction is a great feature of Math. However, it is not exclusive. Any language has this power. English, Spanish, French, and others, have that power. Otherwise, what would Sherlock Holmes have done? “Elementary my Dear Watson”.
Scientific “laws” are created to describe observed phenomena, not to determine what the phenomenon will be like from then on. This is a fundamental issue usually undermined in many schools, colleges and universities. What is this so important? Although it sounds like a trivial semantic issue, this is not. Why? Because, science, different than other human activities, is in constant revision. Scientists are in an unstoppable search for the validation and reevaluation of theory. For instance, in the cases doctors, patients, drugs and diseases, rules are established for how much of a prescribed drug should be given to a person suffering an illness. Determining these rules involves a great deal of work. However, the actual amount of drug that a particular patient should receive depends on many parameters. Some of them are weight, height, race, age. But also, there are many other parameters to be considered, such as dietary habits and ability of the patient to metabolize the drug. These are parameters almost impossible to control, in practical terms. Therefore, rules are created to describe, or predict, how much of a drug is to be administered based on an average response to it. Just like any other law in science. Another example is CO2 and global warming. Some time ago, a well-known politician stated that “CO2 is a natural byproduct of nature”. Beside of the sound redundancy, the fact that CO2 is a natural byproduct is true. This is a natural “law”. But, the “natural” balance between uptake and release of this molecule has been altered by bringing additional release of carbon from fossil fuels and by decreasing the uptake by decreasing the number of forests. Therefore, the statement is misleading. This is one of the dangers of using “laws” without understanding that these “laws” offer a description and not a rule to be complied.
Scientific “laws” are not to be followed or obeyed. These “laws” are tools for our better understanding of the phenomena we study, to facilitate the communication between scientists to speed up the progress in their research. And ultimately, these laws are to be replaced for newer ones with better accuracy and prediction power.