by Joseph Duffy

Created on: November 13, 2009

Past, Present, and Future; Come with Me

References to the past, the present, and the future are common in our routine communications, and we base these references on assumptions that are, scientifically, interesting. How long ago was the past? When does the future begin? Answers to these questions would define the present. This sounds simple enough, yet may be the most mind-boggling idea that we will ever consider.

Events that occur in any period prior to the present moment are considered to have occurred in the past. Events that are anticipated to occur in a period after the present are considered as future events. Did you just read that last sentence at a moment in the past? Yes, by any measure. It has already happened. Have you read the next sentence yet? No, you have not; at least not during this reading. Well, now you have read it, and it has been expedited to the past already!

Therefore, all events are categorized according to their relationship with the present. The present moment separates the past and the future. So, how long is the present moment? If we know how long the present is, then we know all about the past and the future, right?

Let's pursue this idea in specific terms of time that we use; days, hours, minutes, and seconds. Yesterday was definitely in the past, we would agree. Was this morning in the past? Yes, of course it was. How about one hour ago? Yes, it too happened before the present time, and so belongs to the past. Does ten minutes ago qualify as the past? One minute ago? One second ago?

You may be feeling slightly... uneasy... at this point. We are beginning to approach a time/space precipice. We have peered over the edge and are looking down into it. We get the feeling that we will not be able to see the bottom. Let's travel down into it together. Let's go back to the past.

We split our one second into two parts, and we're still not back into the past. We are still a half-second away from it. We divide our partial-second, and then divide again, many times, and the past is staying just out of our reach. The seconds have become milliseconds, then nanoseconds, and now fractions of nanoseconds. We're now flying back towards the past, the partial-nanosecond markers going past us like telephone poles on our time-highway, so quickly they appear as a picket fence. We are very deep into our time/space worm-hole and still can't see the bottom. We are falling at the speed of light, and have not yet reached the past. Is there an end to our journey into the past? There does not appear to be. "Does the past even exist?" we ponder.

An attempt to get to the future may seem more reasonable after our journey towards the past. When does the future begin? Is tomorrow the future? An hour from now? A minute from now? A second from now? Is that the future? Is a half-second from now in the future? Yes, of course it is.

OK, you can do the drill, or, the math, to take you to the future. However, you will never get there. It will always be just out of reach, or a fraction of a nanosecond ahead of you!

We can't go back to the past, nor can we go ahead to the future. A mathematical model does exist for a very limited time travel; on paper only, and for sub-atomic particles. It has not yet been done.

Interesting. The past is behind us by an infinitesimal amount of time, and the future, its corollary, ahead of us. That makes the present an infinitesimally small period of time; not measurable; non-existent, for all practical purposes. Yet, we cannot escape the present. We're trapped in an infinitely small period of time that is traveling at the speed of light, from the past, and into the future.

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