The lab was much as Murdoch remembered from his last visit, although it seemed
to have sprouted a few additional items of equipment. One side of the room was
taken up by a large workbench running almost the full length, littered with
tools and unidentifiable electronics assemblies in all stages of confusion.
Along the back of the bench stood a line of stacked waveform analyzers, synthesizers,
power supplies, and other instruments studded with buttons and covered in screens.
A section of ceiling-high storage racks, crammed with books, boxes, and components,
occupied the space between the bench and the door; the wall opposite supported
a blackboard, covered with calculations above a long table sagging beneath charts
and papers. The machine itself stood along the wall facing the door. Saying
nothing, Charles walked to the console and brought the system to life with a
few rapid taps of his fingers. He glanced at the main screen, issued another
command, and cut off the display. A few winking lights on the main panel were
all that was left to show that the system was active. Then a sheet of glossy,
elasticized paper slid from the hardcopy slot and into the tray beneath. Charles
picked it up, ran his eye quickly over whatever was printed on it, folded it
in two with the printed side inward. Then he looked up.
"Now, Murdoch," he said. "Would you be so kind as to sit yourself down there
at the console." Murdoch obliged. Lee moved forward to watch over his shoulder.
"There s a clock-readout counting down seconds at the top of the screen there,"
Charles went on. "When it gets to zero, I want you to type in a string up to
a maximum of six characters."
Murdoch frowned up at him. "What, anything? No particular length?"
"It does not matter. Anything you like."
Murdoch shrugged. "Okay." He waited for the zero to appear and then rattled
in a random sequence. The main screen in front of him displayed:
"That it?" he inquired.
"That'll do," Charles said. He unfolded the sheet of hardcopy that he had been
holding and passed it to Murdoch without saying anything. Murdoch looked at
it; Lee gasped audibly behind him. The sheet read:
1 January 2010, 2038.00 Hours.
TEMPORAL RETROTRANSMISSION TEST. No File Reference.
Manual Input Sequence. Transmission advance 60 seconds.
Although they had been more or less prepared for what to expect, Murdoch and
Lee were too stunned for the moment to say anything. Talking about this kind
of thing in the car from Edinburgh was one thing; seeing it demonstrated was
Lee looked slowly up at Charles, his brows knotted in bemusement. "That. .
that was printed before Doc even knew what you were going to ask him to do.
This really isn't some kind of conjuring trick? Are you saying those characters
were sent backward through time?"
"Aye. Sixty seconds, to be exact." Charles looked back at him impassively.
"They exist!" Murdoch breathed, finding his voice at last. "The tau waves that
you've always predicted they really do exist!"
"So it would appear," Charles agreed.
As Murdoch slumped back in the chair and began turning over in his mind what
it all meant, Lee gazed with new respect at the array of equipment surrounding
him. Murdoch had told him enough about Charles's work for him to have a general
idea of how the machine worked, but inwardly he had never believed that anything
would come of it. The influence that propagated through time originated with
the annihilation of matter, that is, the conversion of mass into energy. The
mass-energy equivalence relationship became nonlinear at high energy densities;
under extreme conditions, less energy appeared for a given amount of mass than
traditional theory said ought to. The hadrons decay into quarks that Charles
had mentioned had been the first instance to be noticed; at the high energy
density prevailing inside the infinitesimally small volume of the interaction,
less gluon binding energy had been measured than had been predicted. Where did
the rest go? According to the theory developed by Charles and his colleagues,
it had propagated away as tau waves and rematerialized as mass-energy at another
instant in time. Because of the small scale of the events, the resulting time
shifts had been of the minute order that Charles had described. But at higher
energy densities they promised to be more.
Charles s machine employed a laser like pumping technique to generate energetic
gamma photons, which in turn bred electron-positron pairs. The positrons were
channeled by tuned fields and directed at a confined, negative space-charge
to produce the sustained annihilations that the process demanded. Unlike the
giant particle accelerators, which were designed to produce a few isolated events
but at enormous energies, this machine produced many events at moderate energies
within a tiny volume of space; it was the energy density that mattered. That
was why the machine didn't need to be as large as the whole Storbannon estate;
it also explained why the discrepancies attributable to the tau waves had remained
undetected through the earlier decades of particle physics.
The result of the annihilation process was a burst of conventional energy,
which was absorbed by a cooling arrangement, and a pulse of tau radiation that
would reappear in detectable form elsewhere along the time line. The energy
of the gamma photons could be varied, enabling the point in the future or in
the past at which the tau pulse would materialize to be adjusted with a high
degree of precision. The machine therefore functioned more like a telephone
than a radio; the sender could "aim" a pulse at a selected instant, in the past
for example, but a receiver in the past, or future, had no means of "tuning
in." A receiver could do nothing but wait for incoming calls. Lee rubbed his
chin while he looked at the equipment again. The shock was wearing off, and
he was beginning to think more coherently. "So what s its ... its range?" he
asked. "How far back can it send?"
"That s determined by three factors," Charles answered. "The magnitude of the
pulse sent, the sensitivity of the receiving detector, and the absolute velocity
of the Earth through space. You see, the tau pulse reappears as detectable energy
at the same point in space as it was generated. Theoretically the profile of
the reappearing energy wave forms a spherical surface that expands at light-speed
about that point with increasing distances back along the timeline. That s the
mathematical limit. Inside that volume, the intensity falls off exponentially
from the center-point. The signal exists everywhere inside that expanding volume.
However, to receive it, the receiver can only be up to a certain distance from
the center of the wave pattern, depending on how sensitive it is."
"So that s where the velocity of the Earth comes into it," Lee said. "The Earth
will have moved between the time of sending and the time of receiving. You can
only send as far back as corresponds to moving the receiver to its limit of
"Exactly," Charles confirmed. "According to the data from Doppler shifting
of big-bang background radiation, the Earth moves about twenty-one million miles
in a day. The detectors in the machine will operate reliably up to approximately
one hundred and forty-five thousand miles from the center-point of the wave
pattern produced by the level of tau pulse that this machine sends. If you work
that out, it gives you a range of just about ten minutes."
Lee shook his head in wonder and stared at the characters still preserved on
the screen in front of Murdoch. "So how long have you had it working now?" he
"Only since two days ago," Charles told him. "I got it to work for the first
time the day before I called Murdoch. Even Ted Cartland hasn't seen it yet.
I called him a few minutes before I called you, Murdoch, but he s stuck in Manchester
and won t be able to get away until tomorrow morning." Charles cackled wheezily.
"The poor fellow was becoming frantic when I talked to him again, earlier today."
Murdoch was only half listening. He was still staring at the console, mentally
replaying each step of the demonstration that Charles had given. The question
going through his mind was obvious. Finally he looked up at Charles. "When you
set this machine up a few minutes ago, you got the hardcopy first. Then you
started up a program that would time-out after sixty seconds and send back whatever
I typed in. Is that right?"
"Yes," Charles said simply.
Murdoch thought for a moment longer. "Okay. Let s ask the hundred-thousand-dollar
question: What would have happened if I d simply decided not to key in anything
at all after the sixty seconds? What would have happened to the characters that
were already on this sheet? How could they have gotten there?" Charles nodded
as If he had been waiting for Murdoch or Lee to ask that, and moved forward
to reinitiate the system. Then he stepped back. "Try it and see," he invited.
Murdoch looked at the hardcopy slot expectantly and waited. Behind him, Lee
moved closer and watched intently.
Murdoch s face knitted into a puzzled frown. After a while he looked up at
Charles, but there was no surprise in Charles's expression. They waited. "I
don t believe this," Lee murmured at last. "It's no different than last time.
Surely an intention inside somebody s head can't make any difference to what
the machine does. That s for ESP freaks."
"Wait," Charles told them. They waited.
Suddenly the slot ejected a sheet of paper. Lee leaped forward and snatched
it up. "It says MURDOC," he announced.
"When was it sent?" Murdoch demanded.
Lee checked the time printed on the sheet and glanced at the time-of-day readout
on the console. "It s still set up for sixty seconds," he said. The countdown
display had appeared at the top of the screen to confirm his words.
"Right," Murdoch declared. "We'll just see." He sat back in the chair and folded
his arms in determination. Clearly he had no intention of doing anything when
the zero arrived. Charles watched, but said nothing. The final seconds ticked
by; Murdoch and Lee became visibly tense. Then the zero appeared. And that was
that. The paper with its printed record remained in Lee s hand, and time marched
on past the deadline regardless. Two faces jerked round toward Charles, demanding
"I don t know," Charles said quietly. "I don t know who sent that, or where
from, either." The other two were too confused for a moment to say anything.
Charles stepped forward again and used the touch board to bring up a color
display on the screen. It shows a horizontal line across the bottom, annotated
with numbers like the X-axis of a graph with zero at the center; above the line,
the main area of the screen was divided vertically into three broad bands: a
central white one separating two of gray. "This is a graphical representation
of the machine s window of range," Charles explained. "The horizontal axis is
time, with the present instant corresponding to the zero in the middle. The
white zone is twenty minutes wide; that s the window of the machine s current
range, extending ten minutes forward and back. The gray areas on either side
are the edges of the future and the past lying outside the ten-minute range."
To the left of center inside the white area, they could see a short red bar
standing up from the scale at the point denoted by 6 six minutes into the past,
and a similar, but dotted, red bar at 5 minutes. There was a second pair of
bars, this time blue; the solid one was at 1½ minutes, the dotted one at ½ minute.
"Those two solid lines represent signals that the machine has received and logged,"
Charles explained. "The red one at minus six minutes is the random sequence
of characters that Murdoch sent back a little while ago. Some of the control
bits sent with every signal denote the time of transmission, so the computer
can plot on the display when the signal was sent, which it does by adding a
dotted line of matching color in the appropriate place. You can see that the
dotted red line is a minute ahead of the solid one in time. If you watch closely,
you should just be able to make out that the whole pattern is creeping slowly
to the left as time advances. Thus the zero in the center always corresponds
to the current instant." Charles paused and took a long breath, as if he were
being forced to say something that he didn't really believe. He raised his arm
and pointed at the second, blue pair of bars. "The solid blue line, now at minus
two minutes, represents the reception of the signal that Lee read out two minutes
ago. And the corresponding dotted line" he pointed with his finger "is the machine
s reconstruction of where it was sent from a point in time that is now one minute
behind where we are right now." He stopped speaking and waited for the protests
that he knew would come.
"That's crazy!" Murdoch exclaimed. "I didn't send anything one minute ago.
You were both watching me. Nobody sent anything one minute ago. There has to
be something screwy with the system. How could- What the? . . ." He sat forward
abruptly and stared wide-eyed at the screen. A solid green bar had appeared
right on the zero-point of the scale, indicating that another signal had been
received at that very instant. At the same time a dotted green bar had appeared
sixty seconds ahead of it sixty seconds in the future. The hardcopy slot disgorged
"It says 'CRAZY," Lee told them in a bewildered voice. "What in hell s going
A solid yellow bar appeared at zero to the right of the green one, which had
already moved a few seconds leftward into the past. Its dotted yellow companion
was well over to the right of the white area, denoting that something had come
in from about eight minutes in the future. Charles touched a pad to deactivate
the hardcopy unit. "We can look at what the signals actually say later," he
said. "I don t think it matters all that much for now." It was almost as if
he knew what was going to happen next. The display suddenly went wild. Bars
of every shade and color added themselves at the zero-point as fast as the ones
already there could shuffle out of the way, producing a rectangular rainbow
spectrum that steadily extended itself relentlessly toward the left. At the
same time the right-hand half of the white area, representing the future ten
minutes of the machine's range, filled haphazardly with matching dotted bars
to complete each pair. Murdoch slumped back in the chair, shaking his head.
The solid bars merged into a block of color that grew until it covered the
full ten minutes of the past. By that time the isolated red and blue bars with
which the whole thing had begun had been pushed out of the white area completely,
and were now standing alone in the left-hand gray zone, beyond the ten minutes
of the machine s range; almost twenty minutes had elapsed since Charles s initial
demonstration. And then Murdoch noticed something. He sat forward and peered
closely at the block of colors denoting incoming signals. The block was not
completely solid; there were a few thin, scattered gaps, indicating points in
time during the previous ten minutes at which no transmissions had been received.
That much was fact already recorded and firmly sealed in what was now the past.
A thought occurred to him. He pointed toward the screen and looked up at Charles.
"Those small gaps there," he said. "Could we set up the machine to send a signal
back into one of them?"
"We could," Charles answered. "Which one?"
"How about that one?" Murdoch pointed. Charles went quickly through the routine
of initiating the system to transmit and set the time-shift to select the gap
that Murdoch had indicated.
"It's all yours," he announced.
Murdoch studied the display for a moment and paused with his fingers an inch
from the touch board while he thought about exactly what he wanted to do. He
licked his lips and mentally composed a message. Anything would do any nonsense
word sufficiently distinct to be identifiable, such as MURDOC or CRAZY or...And
then it slowly dawned on him. He was not going to prove anything or uncover
anything sensational. What else did all the bars crowded together across the
screen tell him but that somebody some where, some time had already asked the
same question as he, and was trying to do the same thing. And that somebody
wasn't getting any answers. If he were, why did he keep trying the same thing
over and over again? Doing so obviously wasn't getting that somebody anywhere;
there was no reason to suppose it would get Murdoch anywhere either. He drew
his hands back from the touch board and sank back with a sigh to find Charles
nodding slowly, as if Charles had already read his mind.
"You were thinking of trying to fool it, weren't you?" Charles said. "The screen
says there were a few times in the past ten minutes at which nothing came in.
Fact. You wondered what would happen if you tried sending something back to
one of those times anyway. How could that be reconciled with what's staring
you in the face? Am I right?"
Murdoch nodded. "You've thought the same thing, haven't you?"
"And?" Lee asked.
"I never tried it," Charles answered. Then his voice took on a mysterious note.
"Or at least if I did, I don t know anything about it." He looked from one to
the other and took in their puzzled frowns, then waved a hand in the direction
of the display. "Look there. Who sent all those signals that are plastered all
over the place? A lot of them were sent in what has become the past already,
but none of us here sent them. Somebody must have." The statement voiced what
was already written across Murdoch s and Lee s faces. Charles activated the
hardcopy unit to obtain a single-sheet summary of all the messages that had
come in. He scanned quickly down it. "There s no real rhyme or reason to any
of it," he told them. "Things like TEST1 and TIME1 . . ? Here s an interesting
one. It says, GAPFIL. It suggests that perhaps whoever sent it was thinking
exactly what you were thinking, Murdoch." He handed the sheet to Murdoch and
proceeded to shut down the system. The mystified look on Murdoch s face deepened
as he read. "What are you getting at, Grandpa? Are you trying to say that I
did send all this? That s ridiculous!"
"I don t know," Charles replied. "You tell me. Are those the kinds of words
that would have occurred to you?"
"But it worked," Lee murmured. He was massaging his brow with his fingers "That
first test you showed us when we came in it worked."
"Aye," Charles agreed. "When Murdoch had no idea of what I was going to ask
him to do, it worked. But as soon as he knew what to expect and began forming
ideas in his head about trying to fool it, we got nothing but nonsense from
that point on."
"I still say the whole thing s impossible," Lee insisted. "It's what you do
that affects what comes out of a machine, not what you might do or what you
think of doing."
"Yes, but what you think now might be the cause of what you do later," Charles
pointed out "And that s the kind of thing we re messing around with." He started
for the door; Lee turned to follow, and Murdoch stood up and moved away from
the console. Charles went on, "I think what it proves is that idle playing around
like this isn't going to help us make sense out of it. We need to sit down and
work out a systematic approach. I agree with you, Lee. I don t believe in mystical
forces or any of that trash either. As I've said, I've only been working on
this myself for a matter of days, so I don t pretend to have many answers as
yet. This whole thing takes us into a new realm of physics that s stranger than
anything you can imagine. But I believe it is part of physics, nevertheless,
and there is some kind of sense at the back of it all. That s what we have to
see if we can work out."