A Theory of Relativity

When asked to explain his theory of relativity to a group of reporters and non-scientists, Einstein once said, “When a man sits with a pretty girl for an hour, it seems like a minute. But let him sit on a hot stove for a minute and it's longer than any hour. That's relativity.” This was his way of conveying to a lay audience that fixed periods of time can have different meanings depending on the observer’s frame of reference.  I believe the same holds true for different periods in our lives.

I recently began the fifth – and hopefully final - year of my PhD, and sometimes it’s hard to believe that four years have passed by already.  It feels like it was just a few months ago that I began the program with a cautious optimism, occasionally lamenting the idea that I had consigned myself to a lifetime of pupildom.  But the time feels like it’s gone by in a flash.  When I compare this to the five years I spent in high school, that period of my life seems like an eternity.

I’ve long theorized that this apparent disparity in the time continuum can be at least partially explained by a form of relativity.  As a teenager between the ages of 14 and 19, five years represented roughly 30% of my entire lifespan up to that point (I’m averaging this fraction over the five year period).  Now that I’m in my late twenties, the four years I’ve spent working on my PhD represents less than 15% of my current lifespan.  Looking at this number from the frame of reference of someone midway through his or her high school studies, that timeframe is the equivalent of less than 2.5 years.  In other words, due to relativity, the past four years of my life appear to have gone by almost twice as fast as they would have when I was 16.  I suspect that this occurs because, as we get older and we accumulate more memories and experiences, the lens through which we view the passage of time is scaled according to how much time we’ve experienced.  So for a one-year-old, a year feels like an entire lifetime because, in his or her reference frame, it actually is an entire lifetime.

We can extend this calculus over an entire life cycle to reveal some interesting conclusions.  The average Canadian has a life expectancy of approximately 78 years.  However according to age relativity, from the perspective of an eighteen year old, one can expect to feel like they have lived a total of just 44 years when their chronological age is actually 78.  This result leads to the unfortunate realization that, in addition to being the age of consent, 18-year-olds are nearly middle-aged, relatively speaking.

This concept helps to explain the near-glacial lack of urgency exhibited by most adolescents.  As an eighteen-year-old I remember feeling like I had seen and done it all, and I took comfort in the knowledge that I had a whole 3 more lifetimes to look forward to.  Three more eighteen-year stanzas would surely be more than enough time for me to eventually get my act together and accomplish everything I hoped for in life.  But clearly, anyone over the age of 30 understands, without needing a calculator, that it doesn’t really work that way.

Of course, this is just a rudimentary attempt to quantify that which we all know exists.  In fact, the true picture might be even worse than my model predicts.  As children and adolescents we are often burdened with more free time than we know what to do with.  But as we get older, moments of pure leisure become less frequent.  This impedes our ability to create memories in later years, thus making each subsequent year feel more truncated than the last.

This theory gives new meaning to – or rather, elucidates – the old adage that “life is short.”  Adjectives like “short” are meaningless unless they are accompanied by some standard against which they can be measured.  In this case the standard is implied.  It’s not that the average human lifespan is short when measured against the vast cosmological timescale (that would be a gross understatement).  No.  The statement “life is short” means that life is much shorter than we think it is, at the present moment.

Some might read this blog and accuse me of being a nihilist.  The opposite is true.  It is precisely the cruelly finite nature of life that makes it so beautiful.  That’s why I believe that we should cherish life as the rare and fleeting gift that it is.