One of the great unanswered questions in physics is that of how we progress through time. When we talk about space, our location in this physical reality, we can travel in any direction. An astronaut or cosmonaut in an orbiting ship or station can move in any combination of six directions in our three dimensional universe. But when it comes to the fourth dimension, time, we can only move at a constant rate and in one direction: forward. If we travel fast enough, we can slow down our progression through time, but only relative to others who are not traveling at the same speed¹. We can not move in the opposite direction. It’s a principal physicists agree upon, but we still don’t fully understand why this is so.

When we make decisions, they affect our present and our future. But our decisions do not affect the past. This is an axiom which most people typically do not question, even though we don’t fully understand why this is so. But we often question how things might have been different had different choices been made or different events occurred in the past. This type of reasoning can lead to emotions of regret because we imagine a different reality than the one which we currently live in.

Anti-abortion and human rights activist are notorious for talking about the many Mozarts who were never allowed to be born. Stephen Jay Gould once said “I am, somehow, less interested in the weight and convolutions of Einstein’s brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops.”

While these hypotheticals may invoke an emotional response, they are divergent from reality. When we wish we had made a different choice or wonder what might have happened, we do ourselves a disservice because the nature of our universe makes it impossible to know what the results of those outcomes would be. Who we are, as a result of our choices, as a result of the circumstances of the world, is exactly who we are. Nothing more. What could have been is an impossibility. We can not change the past. Those millions of children who were never born, the millions killed from bombs, land-mines and soldiers are gone. They were not and are not potential Mozarts or Einsteins. They are simply no longer alive.

Science involves controlled experiments to prove or disprove theories. We can take complex problems and break them down into many small individual problems and attempt to prove or disprove individual pieces. In this way, things as complex as evolution can be studied using techniques such as the Lenski E. coli long-term living experiment, a crucial experiment in the path to understanding evolution. But even in the Lenski example, the experiment must be replicated and be independently verified before there is wide spread acceptance of the results. Because of the length of the experiment, this could take a very long time and we may discover many new results in the process.

But when it comes to complex societal issues and the idea of “what could have been,” in terms of human choice and interaction, there is no way to create an experiment. We can not create a control version Earth and several experimental versions of Earth where we add or remove certain choices, certain governments or key individual people. We can not break down the flow of civilization into small sets of controlled experiments. Even in the situations where it would be possible, it may not always be ethical.

This may be the only life we know, on the only home we know. Therefore, we cannot live as if to continually examine what could have been or what was possible. Everything we have is a result of what has happened. The cliche “If we do not remember the past, we are doomed to repeat it,” breaks down because the situations of the past are rarely the same as the situations of today. They might be similar, but it is impossible to say, in the context of history, with scientific certainty that this caused that. More often than not, humanity has a very limited and selective short term memory, so for even the events that are empirically similar, we easily forget anything we may have learned from the previous event.

It is a great irony, since so much of who we are as humans is built entirely out of those experience from the past. We are not the societal creatures we are without the events that transform us, yet this inability to escape the things that were and that have happened is also one of our greatest detriments from being able to live in the present, to think meaningfully and to be here now.

“In the tradition of non-theism, however, it is very direct that the case histories are not particularly important. What is important is here and now. Now is definitely now. We try to experience what is available there, on the spot. There is no point in thinking that a past did exist that we could have now. This is now, this very moment, nothing mystical, just now, very simple, straight forward. And from that nowness, however, arises a sense of intelligence, always, that you are constantly interacting with the reality one by one, spot by spot, constantly. We actually experience fantastic precision always. But we are threatened by the now so we jump to the past or the future. Paying attention to the materials that exist in our life, such rich life that we lead, all these choices take place all the time, but none of them are regarded as bad or good, per se, everything that we experience are unconditional experience. They don’t come along with a label by saying that this is regarded as bad, this is good, but we experience them but we don’t really pay heed to them properly, we don’t actually regard that we are going somewhere, regard that it is a hassle, waiting to be dead. That’s the problem. That is not trusting the nowness properly but what is actually experienced now possesses a lot of powerful things. It is so powerful that we can’t face it. Therefore we have to borrow from the past, invite future, all the time. Maybe that’s why we seek religion. Maybe that’s why we march in the street. Maybe that’s why we complain to society. Maybe that’s why we vote for the presidents. It’s quite ironical, and very funny indeed…” -Chogyam Trungpa, Rinpoche

¹ J.C. Hafele and R. E. Keating, Science 177, 166 (1972)