Experimento mental para comprenderlo mejor.
Paradoxically, it is a concept as hackneyed as it is ignored. It is, at the least, curious, the number of times we refer to it a day and, nevertheless, its nature resists our understanding..
Tiempo, Pag.15
The theory of relativity
At the beginning of the twentieth century, the theory of relativity was formulated by Albert Einstein, who published his theory of general relativity in 1915. Perhaps the greatest of physicists, he gave humanity an incredible exercise in intuition, and his predictions continue to be fulfilled and still surprise us.
He argued that space and time were inseparably linked and that it was not a rigid structure. On the contrary, it was dynamic
and could be deformed.
Digresiones, Pag.25
Let’s stay with the idea that time, as we have learned and internalized, consists of the mechanical measuring of the incessant transformation that takes place in and around us, and let’s recall what we know about time thus far:
•Masses slow down time.
•Speed slows down time.
•We don’t know what it is.
Tiempo, Pag.41
​The grammar we use to refer to time is the first barrier that we have placed between us and its understanding. The act of talking about the “passage of time,” as it passes, as it progresses, and that “time passes” faster or slower, requires our brain to travel through an intricate labyrinth between us and its true nature. Amid this labyrinth are our perception and our tradition, and the way both aspects have been combined and projected to this day. Alluding to time in the third person and the inability to physically perceive it, as well as our humble attempt to master it, with different more or less sophisticated measuring instruments over the centuries, has not helped us understand what science currently tells us: time passes slower ... under certain conditions.
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In this way, during this exercise, we will give the expression “wasting time” a literal meaning. We will forget that we use it to describe a period that we spend doing something unproductive and, in our minds, we will reinforce the idea that each one of us has a certain amount of time and we progressively lose it. With greater or lesser resistance, but we always run out of it, like a struggle with death or money in a casino...
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If “high gravity spas” existed, they probably would not be very successful. The truth is that they would not coincide with the motivations that push us today to get cosmetic touch-ups or anti-aging treatments. Vanity moves us to do this, not the desire to outlive others. A trip to the future would do just that: we would outlive our environment, but we wouldn’t accumulate the experiences, feelings, and thoughts that shape and mature us. We would have the same feeling that we have all imagined, that people, who in recent decades have sought out cryogenization, would have if they were to come back to life at some point in the future.
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To have the perception of having traveled to the past, we must “depart” from the present of the place to whose past we intend to travel. However, after we recognize the fact that everything and everyone around us at the time of our departure has already lost the time that brought them to the state in which we perceive the start of our journey ( and as we have already discussed, the second law of thermodynamics reminds us that physical phenomena are irreversible), it becomes obvious that we could never reencounter them in a state previous to the one they had when we departed. Hence the impossibility of traveling to the past.