Everything as it was before

"To regret a past pain in the present is to create another pain and suffer again."

William Shakespeare

The well-known Portuguese expression "tudo dantes como no quartel de Abrantes" refers to what always remains the same, unchanged. But what if the past could be changed? Few questions in contemporary culture excite our imagination as much as the possibility of traveling back in time and altering the past.

At the beginning of the last century, Albert Einstein, with his theory of relativity, laid the foundations for our modern understanding of time and space. This theory has become one of the fundamental principles of modern physics.

The short version of the theory is based on two ideas: the first is that all things are measured in relation to something else, i.e. there is no absolute frame of reference; the second is that the speed of light is constant and an upper limit of nature.

Based on these ideas, time travel becomes real and measurable. Therefore, an observer traveling at high speed will experience time at a slower pace than the other observer. In other words, the faster you travel, the slower you experience the passage of time.

Scientists have already carried out experiments to prove Einstein's theory. In the most classic of these, two clocks were perfectly synchronized at the same time. One of these clocks remained on Earth, while the other was on a plane that traveled in the same direction as the Earth's rotation. After the plane had gone around the world, the scientists compared the two clocks and found that the plane's clock was traveling slightly slower, at a rate equivalent to one second per second.

In short, to travel back in time, all you have to do is accelerate. And depending on the technology used, it would be possible to travel back days, months, decades and even billions of years. We could witness the life of the dinosaurs, the evolution and destruction of humanity, the end of the Earth and the Sun, or the collision of the Milky Way with Andromeda.

If time travel is scientifically possible, would it be ethical and moral, or advisable, to go back in time to correct our mistakes?

We all have regrets, remorse, sorrows or a desire to do something differently. That's why the idea of going back in time and correcting this penance is so tempting.

Who wouldn't want to go back in time and get Paulo Isidoro to mark Paolo Rossi in the fateful game at Sarrià in Spain in the 1982 World Cup? Or warn Barbosa, goalkeeper of the 1950 World Cup team, to protect the left corner of Uruguayan Ghiggia's shot? Or go back to May 1, 1994 and convince Ayrton Senna not to take part in the Imola Grand Prix.

We could cite countless examples that, for their collective merit, would merit a rearrangement of the past. Wars, terrorist attacks, the rise of autocratic tyrant leaders, climatic tragedies, air and naval accidents. The list is so long that the only solution to resolve all the issues at the same time would be to return to the initial moment of the Big Bang or, for religious Catholics, to prevent the serpent from seducing Eve, and then Adam, into eating the forbidden fruit.

Would changing the past bring more happiness? There are ethical and moral implications to be considered, as well as the lack of knowledge of the consequences of this change in people's lives and the preservation of the natural course of history.

Philosopher David Lewis, addressing what he called the grandfather paradox, discussed the contradictions of time travel and questioned whether history would somehow adjust to the changes.

In the utilitarian and consequentialist view, changing the past to avoid tragic events, such as wars or natural disasters, is morally correct if it results in less global suffering. The philosopher John Stuart Mill argued that morality should be based on maximizing happiness and minimizing suffering, which could be applied to these situations.

Benedetto Croce emphasizes the importance of history as a discipline that seeks to understand the past, preserving its authenticity and avoiding interventions that distort the historical truth. Therefore, preserved history helps us understand how the world and society have evolved over time, allowing us to learn from their mistakes.

The philosopher Immanuel Kant argued about morality based on action in accordance with duty, while Jean-Paul Sartre explored the morality of individual choice, which could be applied to these decisions.

The complex ethical and moral dilemmas involved in going back in time and changing the past arouse different views. All these philosophers have contributed to the discussion of these issues, each with their own unique perspectives and approaches.

For a long time to come, time travel will only be possible in physics and on the pages of science fiction books. Therefore, traveling to the future or the past to correct our mistakes will remain only in our imagination.

These approaches make us reflect on the morality of human behavior, given the unlimited possibilities that time travel brings us. We are called to an intellectual, ethical and personal duel, which questions the nature of our behavior beyond moral constraints.

The truth is that, despite all the teaching we've received throughout our lives that "it's important to forgive in order to be forgiven", "accept the facts as they are", "turn the page", etc., if we had this power, we'd hardly stop using it to make amends for the past, whether for an altruistic or private purpose, such as the loss of a loved one in an accident. We act as we do because we think it's right to change the past.

If I had this power myself, I would have a list of issues to deal with. One of them would be to warn my great-grandfather to withdraw his investments in the New York Stock Exchange before October 24, 1929.