Time is such an integral element in our lives sometimes it’s hard to imagine it as a matter of debate, a dimension that is both exact and yet able to be perceived in multiple ways. I recently read an incredible list of facts we should all know about time. Here are the most interesting elements:

Time exists–this is certain. A little over a century ago, though, Einstein put forth his theory of relativity which distorted Newton’s classic physics model and thereby the previously accepted understanding of time. Einstein explained that times elapses differently near the speed of light and near black holes. No, most of us will not experience the passage of time in these circumstances, but we’re all familiar with the sensation that time starts to speed up as we get older. And indeed this phenomenon is representative of time being experientially relative.

And yet we are so dependent on time that it influences our cognitive development, communication, and decision processes. The ability to imagine alternative outcomes was necessary for early survival, while our linguistic tenses allow us to discuss these possibilities as a group.

Speaking of possibility, I had the epiphany in high school that all future events must be probabilistically implicit in the present moment. That is, every large and small event that happens in the future (whether I have a child several years down the road or whether I’m late to work tomorrow) will follow a discrete chain of occurrences, each one following the last because it is statistically possible. Granted, the probabilities of each event are infinitesimal past the events that happen in the next few minutes (whether I get up and refill my glass of wine or play my next move in Words With Friends), and yet they are there. (By the way, I just refilled my glass of wine and now there’s a slightly greater chance that I will be late for my 8 am meeting).

Why is this important? Because of this: the past and future are equally real. Whoa.

But what about the present? Our brains delay our experience by 80 milliseconds, about the blink of an eye, so as to compile the “present moment.” It was only after Janet Jackson’s halftime nip-slip that television broadcasters realized why this is important (who knows what hijinks Madonna would have gotten into during today’s Superbowl if we weren’t on a delayed broadcast). When I read this fact, I wondered if this aspect of consciousness has anything to do with flow, the mental process that artists and athletes describe that circumvents usual perception of time. If your muscles respond before you need to think how to react, does that 80-millisecond lag time get reduced? And if so, does that contribute to the sense that time is slowing down?

Having a heart to heart

Whether we live in the past or accept the future as real, though, time moves forward and so does the natural process of aging. Indeed, there are many scientific experiments in the works that may extend human life, and we have already increased lifespans through modern medicine and decreased threats such as predators, exposure to the elements, and other stressors common to early mankind. Yet studies show that the average number of heartbeats for any complex organism is constant, so long as it is not killed prematurely. The larger a creature is, the more efficiently its cells metabolize, the slower its heart, and the longer it lives. There’s a relatively simple scale that shows the magnitude of all these factors, which shows that each one of us, from hummingbird to elephant, has about 1.5 billion heartbeats.

If we only have a billion heartbeats then, let’s not waste them on worrying about what has happened or what may happen in the past, present, or future. Time to refill that wine glass once more.