[ WP ] While light takes a tiny fraction of a second to pass through a normal window pane , it takes 50 years to pass through `` slow glass '' .

He takes her hand, wrapping her frail fingers in his shaky grasp. “ Come now, ” he says, and the elderly couple walk slowly, hand in hand, to the far side of the podium. 
 
 Her eyes don ’ t leave the ground as she ambles past the velvet ropes encircling the towering pane of glass in the center of the room. Her husband glances at the placard to the right of the window: “ Slow Glass. ” He squints, but the fine print under the bold label is too small for the old man to make out. *No matter, * he thinks. He ’ s been here before. He knows of the wonders of Slow Glass. 
 
 It wasn ’ t always called Slow Glass. “ Dark Glass ” was the preferred term seventy odd years ago when the material had been newly created. A substance so dense, yet structurally nearly identical to glass, that light was all but halted in its tracks by the material. The first manufactured pane of Dark Glass was a wonder to behold even in its early years. No light, not even the slightest reflection, emitted from the glass. Absolute blackness. It was like looking into a hole in the world. 
 
 Scientists knew of the incredible potential of Dark Glass even before it was obvious to the human eye. Light wasn ’ t halted or even fully absorbed by the substance, it was only delayed. The first Dark Glass public attraction—quickly renamed “ Slow Glass ” —was installed in the Smithsonian only three years after the material ’ s inception. A microscopically thin sheet of the glass, protected by infinitely more durable panes of plexiglass, stood in display in its very own room. Because of the incredibly thin width of the glass, the delay was mere seconds. Adults and children alike marveled at the impossible window, waving their hands frantically on one side of the glass and running around to the other side, just in time to see their delayed images repeat the motions. 
 
 The first exhibit, along with each subsequent installation, deteriorated quickly. The fine sheets of Slow Glass proved too brittle to withstand the test of time, and due to the high cost of producing the material, manufacture of the glass was soon for scientific use only. The public could only learn of Slow Glass through articles and old videos. 
 
 Until one day, nearly a decade after the invention of Slow Glass, a wealthy entrepreneur purchased one of the oldest panes of Slow Glass, a three-and-a-quarter inch thick slab that towered over eight feet high. “ Dark Glass ” would ’ ve still been an apt name for the massive window, as no light had penetrated through to the other side in all that time. Its creators estimated that it would take up to a half a century for light to pass through, if at all. No one was entirely sure that the glass wouldn ’ t stay just as it was—pitch black. 
 
 Still, as soon as word got out that this mysterious “ window ” was open for public viewing, the masses flocked to see it. The crowds came and went with varying reactions—mild wonder for some and disappointment for others. This was nothing like the interactive Smithsonian display they ’ d all read about. This was a dark—though impressively dark—statue, and nothing more. Still, though the wave of viewers slowed to a trickle, the Slow Glass monument remained open. 
 
 Today, the Slow Glass Monument is a much more popular attraction. A line runs all the way through the front doors and around the corner. A specialized clock stands by the entrance, but it doesn ’ t tell you what time it is at the moment. It ’ s set to a time and date exactly 50 years, three months, one day, and seven minutes in the past. The exact length of time it takes for light to pass through the Slow Glass. 
 
 There ’ s only one way to skip the line—no fast track purchases or reservations, just the possession of a valid ID that matches a name from the visitor ’ s logbook, 50 years, three months, and one day ago. On this day, there was only one name. 
 
 He stops in front of the monument, and she falls into place beside him. She ’ s tired, he knows. It ’ s been a long time since she ’ s had the strength to leave her bedroom. He clutches her hand tighter, and the shaking steadies. She glances up at her husband, weary, but a smile crosses her face, wrinkling the already-present creases at the corners of her eyes. 
 
 He smiles back, but says, “ Don ’ t look at me, my love. Look there. ” 
 
 Her eyes follow his raised finger, and she turns to look at the window before her. Through the glass, she sees the room is empty. It ’ s strange though, behind the window, the wall seems to be painted a different color. The floor tiles look different as well. Something nags at the back of her mind. What had Henry told her on the way over here? They were going to see a special sort of window, she remembers that much. 
 
 Then, she gasps. 
 
 A young man with wispy, brown hair appears behind the glass. He seems flushed and he bends over to catch his breath, smiling as he does so. The man is clad in a black tuxedo. 
 
 “ I know him, ” the old woman breathes, her hand moving towards the rosy-cheeked youth. 
 
 Behind the Slow Glass, the man speaks. No sound can be heard, of course, until the old man opens his mouth, his words matching the movements of the young man ’ s lips. 
 
 “ You asked me the other day, ” he says, “ if I was sure about this. If I was ready. You wanted to know if I ’ d still love you in a year. In ten years. In fifty. ” 
 
 Her eyes begin to glisten. 
 
 He continues. “ Darling, a whole century could pass and my love for you would only grow stronger. Maybe these are only words now, but time will be my true answer to you. I love you, Hannah, and I always will. ” 
 
 Through the glass, the young man checks his watch. He glances behind him, then back to the glass, and then darts away. 
 
 “ Sorry to keep it brief, ” Henry says, his voice rough from age and emotion. “ I didn ’ t want to be late for our wedding. ” 
 
 -- - 
 
 Fifty years, three months, one day, and seven minutes later, a young couple stand on the other side of the Slow Glass Monument. 
 
 “ What do you think they ’ re saying? ” she asks. 
 
 He puts his arm around his girlfriend and shakes his head. “ No idea. Wish this thing came with sound, huh? ” 
 
 She rests her head on her hand and watches the misty-eyed older couple embrace through the glass. “ They really look like they ’ re in love, don ’ t they? ” 
 
 “ Yeah, I suppose. ” 
 
 “ I wonder what they were watching, through the window, I mean. Imagine—whatever it was happened over a century ago! ” 
 
 A bustling family of five crowds in front of the Slow Glass, and the two move onwards. He glances back at the window, though, just before they leave. The old man and woman walk slowly away from the glass, hand in hand, returning to the past.
