A Time To Every Purpose

by Ian Andrew

  “To be fair, the Führer and the Reichsführer both fully grasp it.” She stopped talking and looked rather sheepishly at him. “I’m sorry Heinrich. I do tend to rant when it comes to this.”

  He smiled at her and said, “It’s ok. I get that you’re passionate about it. But as I said, how did you discover it?”

  “Accidentally, like all good discoveries I suppose.”

  As she passed Francine’s desk she tapped her on the shoulder and gave her a ‘comear’ nod for her to follow them. The three of them passed through a small, square cleanroom and headed back to the High Powered Laser Lab. Heinrich hesitated a little in the cleanroom as he walked over sticky-pad mats that he guessed took off any debris from the soles of his shoes. Leigh swiped her access card and keyed in her security code to the door and waited for Francine to do the same. Once the mechanism had accepted the dual entry protocol it clicked open.

  “Thanks Franci.”

  “No problem.”

  Francine headed back to her desk whilst Leigh held the screening blackout curtains apart. “Come on Heinrich,” she called to hurry him up.

  The High Powered Laser Lab, it turned out, didn’t have a nickname. It was simply known as the HPL and was a long wide space with long, wide, solid wooden benches running most of the length of the walls. Within the rest of the room, set at irregular gaps and angles, were other workstations and fixed shelving. Most of these were loaded with an array of different shapes and sizes of equipment, none of which Heinrich recognised. Leigh motioned him over to the nearest workstation.

  “What do you know about Lasers Heinrich?”

  “I have a pointer that I use when I do briefings,” he smiled lamely, before adding, “not a lot to be honest.”

  Leigh reached under a small bench and brought out a 30cm long, 20cm wide and 15cm deep metallic box.

  “Okay, have you ever flown on a Luftwaffe transport or a Deutsche Lufthansa Jet?”

  “Oh yes, many times.”

  “Ever end up in the wrong city?”

  “Not me. Luggage yep, but no, not me.”

  “Well, this is one reason why not. It’s a ring laser gyro.” She looked at him and recognised on his face the look she must have given him when he had mentioned his village. She decided to start from scratch.

  “Mmm, okay Heinrich, this is Basic Lasers 101, ready?”

  He nodded.

  “A standard laser works by bouncing a light beam back and forward between two mirrors. One of the mirrors is only semi-reflective so some light actually passes through it. The laser beam is the small part that escapes out after each reflection. But a ring laser gyroscope like this one,” as she removed the top cover of the box, “has four mirrors arranged in a closed ring. What we do then is send two laser beams around the ring, one clockwise, the other counter-clockwise. The equipment basically tunes itself so both of the beams have the same wavelength and being lasers the wavelength is pure and coherent.” She looked at him. His brows had creased.

  “Coherent Heinrich, they all go the same way and all together.”

  He was frowning.

  She tried desperately hard not to sigh.

  “OK. A normal light bulb scatters light everywhere. A laser light is like sheep being herded by a very diligent dog. We send light, or sheep, in one direction and the same number of sheep in the other direction. Imagine one set of sheep are white and one set are black. When they meet back at the start they cancel each other out. No sheep left. Got it?” He nodded so she continued quickly before he didn’t get it again.

  “So, when the beams of light come back together again after going around our four mirrors in opposite directions, they’re sent to an output detector. Given that the speed of light is a constant and the cavity doesn’t change then both beams are identical and because they are going the opposite way from each other, they cancel each other out. Just like our sheep.”

  He nodded and smiled. She understood he understood. She hadn’t the heart to tell him this is how she would have briefed first year high school kids. She reflected that even then it would only have been the slower ones that got this version. She decided to press on.

  “However, imagine if the cavity where the mirrors are moves or twists. Because it’s mounted in an aircraft and the aircraft moves so we can make that movement make the cavity change shape. If that happens then the distance around the circle for each set of sheep will be different.” She paused and he nodded.

  “Like warping a running track. To one of the beams the mirrors will be closer together whilst to the other beam the mirrors will have moved apart. Simply put one of the beams will have to travel further and its wavelength will change. When both beams come back together they won’t cancel exactly. We would have some white or black sheep left over. We can measure extremely small variations in the beams wavelength and by calculating how much rotation took place we can determine motion. If we accurately know where the aircraft started from then we should know where we have moved to. Simple.” She looked at him expecting to see his brows creased again.

  Instead he said, “Okay, that makes sense. How do we get from this to looking back in time?”

  “Ah well, as is the way with simple things in science, it isn’t as simple as I might have said.”

  “Now that’s not a shock Doctor.” Heinrich smiled at her and this time held her gaze. Leigh felt her heart skip again. She had an overwhelming desire to reach across, grab him and kiss him hard. She flushed with the imagery in her head.

  “Right Heinrich, no shock at all,” she struggled to control her voice “so, in 2015 ring lasers suffered from two problems, in fact they still do. Lock-in and frequency biasing. Frequency biasing is a peculiar effect only encountered with gas lasers. We used them in Luftwaffe kit, still do in the older stuff. The key to getting rid of it is to use something else and we proposed to use a Quantum Cascade Laser.” She looked to see if he was still following her.

  “Do I want to ask what one of those is?” he said.

  “Probably not, no. Take it from me they are a good thing and very sexy.” ‘Like you’ she didn’t add.

  He smiled, “Sexy science, I’m impressed. Okay, onwards.”

  “Well, as is the way in science, if we put a QCL in then we solve the bias problem but compound the lock-in problem. It’s caused when the ring laser is rotating very slowly, the wavelengths effectively become stuck and the beams lock to the same value.”

  She saw he was frowning again.

  “Simply put all the sheep stick together. There is no difference picked up by the output detectors so the device will not track its position accurately. Basically we will have moved but there will be no spare sheep to count.” Heinrich had stopped frowning and nodded.

  “So we decided to go bigger and more powerful to see if we could get a work around solution. We needed to get the line width as narrow as possible. If we could get it narrow, then we could put more power into it and get more fidelity into each beam thereby ensuring that even the tiniest differences were detected.”

  “I can safely assume that getting narrow width and increased power and therefore greater fidelity is the Rosetta Stone of Lasers?” Heinrich asked.

  “Yep, you have it exactly. Well done. But, we were confident so we built a bigger version of this little ring laser. In fact we built one that was a metre in length on each side. The idea was to see if we could get it refined enough to sense the actual rotational motions of the Earth. Problem wasn’t the laser, the problem was me,” she paused.

  “How’d you mean?”

  “I had taken almost a year to come back into work full-time after the car crash. Even then I still had headaches, and my concentration lapsed occasionally. We had a problem with the kit and I was working late. I reversed the laser input streams to send the clockwise ones round counter-clockwise and vice-versa.”

  “Um, and that was bad?” Heinrich looked slightly puzzled.

  “Well it is if you take one of the most powerful lasers ever bui
lt and only reverse one stream. Basically I sent sixty-four laser beams around and around a ring laser apparatus. We weren’t really sure how at first but the output stages began to amplify the signals and a disturbance happened.”

  “A disturbance?” Heinrich asked quizzically.

  “Come on, I’ll show you, follow me and meet RL-04, it’s even bigger than the one in Toronto was.”

  Leigh led him across to a double door set into a recess in the bottom left hand corner of the lab. As they approached the doors they automatically slid open and revealed a stubby hallway that led to a set of manually operated, triple glazed, opaque-glass, sliding doors. Leigh slid them open and led him into a rectangular room that reminded him of the control hub he had seen in the Reich’s missile defence centres.

  “Welcome to the Thule Room,” she said.

  From just inside the door he could see eight separate control consoles arranged in a reversed-L with four of them facing to the front and four toward the left as he looked. Each one was a single curved desk into which were embedded in some cases two screens and in others five separate displays. On the flat portions of the desks were tracking balls, joysticks, keyboards and data entry pads in a variety of configurations. To the right of the space set back from the consoles was a small raised dais with about a dozen chairs. To the left, running the full length of the room, was a wall of very thick glass. Through the glass Heinrich could see a darkened space of unadorned concrete walls and floor within which sat a similar configuration of equipment as she had shown him on the small bench. The difference was the four mirrors of this laser were each 2-metres in length.

  “Bloody hell, that’s big.”

  “Yep.”

  “Mmm, Leigh?”

  “Yes,” she said hesitantly.

  “That ring laser’s actually a big square.”

  She looked at him and tilted her head a little. “Ah, yes, yes it is. It could also have been three mirrors in a triangle but yep it is square. And now you’re going to ask me why it’s called a ring?”

  “Well, I was but I’m guessing that isn’t important?”

  “Spot on. You ready to see it work?”

  “Uh-huh,” was as eloquent as he could manage.

  Chapter 19

  Leigh stepped up to the left foremost control console and began to flick various toggle switches on the panels.

  “Right, I need your help,” she said and motioned for him to step up to the right foremost console. “See that key in the console near to you?”

  “Yes,” he said, reflecting that it would have been difficult to miss. It resembled an old fashioned clock winding key and it stuck out of a port marked in red and yellow, ‘Master Arm 2’.

  “Well it needs to be turned at the same time as the one I have over here.”

  “Okay,” he said hesitantly.

  “It’s easy Heinrich, relax. I’ll count 3, 2, 1 and turn. On turn you push down and turn clockwise 180 degrees. All good?”

  He nodded.

  “Okay, 3, 2, 1 turn.” They both turned the keys in a synchronous movement.

  The first faint red beam began to show in the next room. As she flicked the final bank of controls the centre of the cavity filled with a dazzling array of crisscrossing laser beams. Most were red but about a tenth of them showed as an indigo-violet shade. Leigh waited until the display looked like a stable set of crayon drawn lines suspended in mid-air before flicking a protective cover off a toggle switch labelled as ‘Master Alignment’. Although transparent to an observer, as she flicked the switch to ‘On’ the thirty-two beams that had been circulating clockwise reversed and a total of sixty-four lasers began to feed their beams into the ring laser apparatus in a counter-clockwise direction. As the beams raced around the ring their wavelengths became fully aligned and coherent. Each time they passed the output detection circuits their combined waves amplified each other like the feedback in a microphone and speaker. Instead of being cancelled out by counter-rotating waves they were all combining. Each time the beams completed their 8-metre circuit they amplified more. At the speed of light the 8-metres did not take long to traverse.

  Heinrich stood mesmerized. He watched as the beams became a blurring purple circle in the middle of the apparatus, but then he began to see something else. A glassy, translucent, almost watery whirlpool forming in the middle of the cavity 1-metre above the floor. Right at the heart of the effect, pulling down in the centre was a small opening, no bigger than a table-tennis ball, but jet black. He could see the hole growing bigger and he could hear a distant rumble.

  “The good news is that the glass in front of us is 10cm thick. When I did this by accident in Toronto the noise was deafening and the rush of air blew me off my feet.”

  Even with the thick glass the noise could still be heard. It sounded like a train coming through a tunnel. He could also hear a faint high-pitched element that moved away in a Doppler effect like a receding ambulance siren. The noise was rising incessantly but it was also focussing. He could tell the noise and the motion and everything that held him spellbound was centred on the hole in the middle of the whirlpool. The hole was getting bigger every second and the whirlpool effect itself was reaching out to fill the cavity between the mirrors. The red and indigo-violet beams he had first seen were now an intense purple light which appeared as an unbroken circle around the edge of the still glassy-surfaced whirlpool. Just as the noise was becoming hard to bear there was complete silence.

  “What happened?” asked Heinrich turning to her, “Did you just switch it off?”

  “No, we just reached stabilisation.”

  Heinrich looked back at the cavity. There was a steady circular ring of purple light forming an outer edge to a completely flat silver disc, 1.5-metres in diameter and suspended 1-metre off the floor. The disc was featureless and looked like a large mirror, laying flat on its back in mid-air. Except that in the very centre was a hole about half a metre across. The hole was jet black in colour and completely opaque. Leigh pressed a few more buttons on one of the forward facing consoles and a screen slid down on the wall in front of her. At the press of another button a projector mounted on the ceiling flicked on.

  “You’ll probably want to turn round and watch this,” she said.

  Heinrich reluctantly turned away from the scene through the glass and found himself looking at an image of the silver disc but from above. He looked back into the apparatus room and saw a small camera mounted on the ceiling looking down at the disc.

  “Heinrich, this is the Time Observation Window or TOW in its raw state. What we’re about to look at has become known simply as a Projection. What you’ll see shortly is an image coming into focus inside the centre portal, or as it’s normally called by anyone who sees it, the black hole. It isn’t by the way.”

  “It isn’t what?”

  “A black hole, we’d be dead if it was, the whole lot of us, all sucked into a gravitational nightmare, but it isn’t so we’re not.”

  “Well that’s good then isn...” Heinrich stopped as the screen on the wall began to show an image. He was looking at a plain brick wall with a LED-clock mounted on it. The clock showed the date and time.

  “This clock, Heinrich, is on the wall at the far end of the room where the laser is. We don’t know why but when the Window opens it always looks at the same place and always twelve hours from current time. We can’t see back any sooner than twelve hours. Hence the reason the clock reads 23:12 on 17 May 2020.”

  Heinrich checked his own watch and saw that she was right. Leigh turned back to the control console and lifted a phone handset. She punched a speed dial button on the bank of switches.

  “Hi, this is Doctor Leigh Wilson, I need an authorisation code for the Projection Request I sent earlier.” She waited, punched a series of numbers into a keyboard and hung up the phone. She moved to another console and entered in more commands.

  The image on the screen blanked out, and Leigh entered a last set of commands on a second keyboard
off to her left. The screen flashed white and then refocused. Heinrich stood in stunned silence as he watched the Projection. He saw Leigh take a couple of draws from a cigarette before standing, putting her notebook and cigarettes away, smoothing her skirt down and adjusting her jacket. He watched as she dropped the cigarette into a waste bin, walked forward to the roadside and shielded her eyes from the approaching headlights. As the car stopped Heinrich saw a Sturmmann in the uniform of the Waffen-SS step out of the passenger side door and salute Leigh. The image froze.

  “51 degrees, 30 minutes and 21 seconds north, 0 degrees, 7 minutes and 51 seconds west, camera position altitude 10 metres, 19:50 GMT on 17 May 2020.” Leigh read the words off a piece of paper she had taken from her pocket. Heinrich looked at the image on the screen then back at her. He ran his hands through his hair and continued to stare.

  “It would appear you are speechless, Standartenführer Steinmann.”

  “It would appear you are mostly right Doctor Wilson.”

  “Want to see anymore? Would you like me to zoom in so you can see yourself at the wheel of the car?”

  “No, I think that’s just fine. Thank you.”

  Chapter 20

  They were back in her office and drinking more coffee.

  “You haven’t said much?” she offered.

  “Well, I’m a bit stunned really. I’ll be honest I was a bit disappointed when you told me the limitations but to actually see it in action. To have a window into the past and to have seen it actually working. What an investigative tool! It’s amazing.”

  “Why thank you kind Sir,” and she dipped her head in a mock bow. “Okay, before I go through the next bit, any questions?”

  “Probably lots, but not at the minute.”

  “Okay then. I opened the first Window in September 2015 but it took us months to figure out what it was and what it could do. After a lot of work we discovered it looked back through the timeline. Then we detected an audio signal. We decided to experiment with transmitting voice back through. We had these great ideas of asking Mozart how he had composed his masterpieces. We also thought we could use it to tell people not to get on the Titanic. That sort of thing. So we set up a test. We put a cheese sandwich, wrapped in greaseproof paper, on a table.”