“It is as if we have been presented with two paths, and which path we take is determined not by the messenger, but by our dimensional limitations in being able to follow the message.”
Phobos lifted an arm and pointed a long, slender finger toward the panoramic view spread before them. “Do you see that star there?” He asked, directing Lamont’s attention to a purple point of light bright enough to cut through the nebular canvas of color. At Lamont’s nod, he continued: “Let’s say that star is 1,000 light years away. If that is the case, then the light from the star has taken ten centuries to reach us. Its photons have traveled for a thousand years—not merely in a straight line, but subjected to the curves and contours of its medium, the effects of gravity and other influences subtler yet.” His voice had taken on an almost musical tenor, as if he was captivated by the beauty of what he was trying to describe.
“Go on,” The newspaperman urged him.
“The light itself is bound by its nature to travel through space at a fixed speed, the travel time being determined by the shape of the space through which it travels. It is, in that sense, much like the ant that has no choice but to follow the circumference of the orange. When it reaches our eyes, however, it plays another role—that of a time capsule. The light contains a multitude of data concerning the star from which it originates, unaffected by the passage of centuries. Information not about what the star is like now, but rather what the star was like when the light began its journey away from it. So you see, the light is in fact subverting the very physical laws to which it would appear to be subjected. While taking a thousand years to reach our eyes, it is nevertheless bearing witness to the star’s makeup at a perfectly fixed moment of time.”
The Martian had become relatively animated now, his bony red hands tracing a line in an attempt to illustrate his point. “If our objective is to follow the light back to the star from which it originates, the nature of that journey is determined by our own limitations. If we were to follow the light’s path through space, it would take us a thousand years to reach the star. But if we were able to follow it through time—or rather, through the packet of quanta fixed in time—we would follow it to the star at the time the light left it. It is as if we have been presented with two paths, and which path we take is determined not by the messenger, but by our dimensional limitations in being able to follow the message.”
Lamont had started to feel a little dizzy. He looked carefully at the intense expression of Phobos’ golden eyes from the deep wells of shadow in which they were set and, fishing for his cup from the tabletop beside him, gulped down the cold dregs of his coffee. “Okay,” he finally said, “So the basic problem is that under normal conditions, we can only follow the light’s message through space, right?”
“If we use ‘normal’ as a subjective relation of experience, yes,” Phobos agreed.
“And Escherspace somehow solves that problem by allowing us to follow the message through another dimension—time, not space.”
Phobos lifted a corrective finger. “Time and space, among other things. The moth exceeds the capability of the ant in regard to travel.”
“So you’re saying that Westward is a time machine?” Lamont asked incredulously.
The Martian lifted a slender hand to his mouth in an expression that, to Lamont, communicated profound disappointment. He stood, towering over the newspaperman. “What I’m trying to show you, Lamont, is that you and I and the light are all time machines. Our physical movements are typically restricted by four-dimensional physics, it’s true. But consider that, in retrieving the temporal message carried by the light, we have surpassed those physics almost without effort.”
“So what does Escherspace do?” Lamont asked, almost desperately.
Silhouetted by the ceiling lights of the command deck, Phobos tapped a long finger against the side of his oversized cranium. “It merely takes the problem out of the realm of the conceptual and into the geometrical.”