Regardless of the object of study, learning takes time. Some lessons might take only a few minutes, others may take a lifetime. In the latter case, one may decide the object of study is not worth pursuing.

When I was in high school I was fascinated by Einstein’s Theory of Relativity and, in those pre-Internet days, read as much as I could on the subject in the few books available. Although special relativity (which deals exclusively with inertial frames of reference, or those which are non-accelerating) can be studied by anyone with high school mathematics, general relativity (that dealing with non-inertial, or accelerating, frames of reference) is mathematically highly advanced; for it, one must master the branch of math called tensor calculus. For a senior high school physics research project, I investigated the life and contribution to tensor calculus of an Italian mathematician named Tullio Levi-Civita. A few years later while doing my undergraduate work in physics, I had the opportunity to take a fourth year course in general relativity. At that point however, my interest had waned and I decided not to take it.

Einstein called time a ‘stubbornly persistent illusion’, and its stubborn for good reasons. Time owes its existence to at least two factors, one objective and one subjective. The objective factor is movement. If nothing moved then the notion of time would cease to exist – how would you know it was passing? The subjective factor is memory. If you had no memory you would not be able to link two sequential events together and, like in the first case, how would you know it was passing? So time’s stubbornness is due to the commonplace observations that things move and that we have memories which track those movements.

In terms of measuring time (i.e. a clock), we need a regular, periodic motion to which to compare the movements of all other things; this is just one application of simple harmonic motion, that well known model to all physics students. Nature provides us with at least a few obvious such motions: the year, day, and month, which are due to the earth’s orbit around the sun, spin on its axis, and the moon’s orbit of the earth respectively. None of these have precise, regular periods, especially not the last of these, but they’re close enough to use as a clock. As time went by (it always does!) more precise and finely divisible units of time were created; nowadays a quartz crystal resonating as a miniature tuning fork provides a signal with these characteristics in most watches and other common devices.

Our time in this life is finite, but the objects of study are seemingly infinite; just look, for example, at the array of academic journals with legions of professional researchers publishing in them. According to the Ulrich’s, the largest periodical database, there are over 300,000 active and online periodicals. There are whole fields of research most people have never even heard of, much less mastered. At the same time, the information age presents us with an endless supply of decontextualised information, which can lead to a very fragmented and confused worldview. We ought to guard our minds and time carefully so we can attain the knowledge we need to become who we want to be and accomplish the things we really care about. I believe those are tasks worth pursuing, but they’ll definitely take a lifetime.