Some of the strangest characteristics of quantum theory can be demonstrated by firing a photon into an interferometer
QUANTUM SHORTS 2015: SHORTLISTED, YOUTH CATEGORY
Dr. Lundberg looked at her phone. She had just received a text. She looked at the phone number; it was one she recognized. She knew what the message said before she looked at it.
“This message is to inform you that your TRD has received a transmission. Read the message on the device itself for more information,” it read.
She glanced down at her watch. There was just enough time to catch the 43 bus home.
On the bus, her mind raced. Was it another false reading? She had been getting a few false positives each month since she set up the device. Eventually she had grown tired of waiting at home for the device to beep, so she set up a system to send her a text in the event of a reading. She tried to keep her schedule clean, so that she was free to go home and check the device whenever she received an alert.
She got off the bus and stepped into the cool, fall air. Her suburban house was more of a laboratory to her, and she spent more time at her boyfriend’s apartment than she did at home. So, walking down her street for the first time in two weeks was refreshing. Since she’d been gone, all the leaves around her house had turned fiery orange.
When she walked in the door she heard a faint beeping coming from the garage. She rushed through the house, not even stopping to take off her coat. She sped past family pictures and a photo of her childhood cat, Erwin. As she got closer to the garage, she began to pass by framed diplomas and certificates from her scientific career. Hung above the door to the garage were three portraits: Einstein, Lorentz, and Fermi.
When she entered the garage, which hadn’t actually had a car parked in it for several years, she looked right at the large machine in the corner. It was about the size of a refrigerator, and had a screen, which was currently flashing. She had worked on the TRD since before she got her PhD. It consumed her attention for years, until she finished building it a year ago. To test it, she had built another, smaller device. It could generate the faster-than-light particles she wanted, and she used these to make sure her TRD worked. But the particles she was really looking for were not something she could just create.
The goal of the Tachyon Receiving Device was to find particles that would be emitted in the future and could be received in the past. The reading she had been waiting for was a message from the future.
She looked at the screen. Normally, when the machine detected a reading, the screen displayed a jumble of mixed-up text, since the reading was false and didn’t have a message embedded in it. But this time, the text looked familiar; it looked like English.
“This message was sent at 6:32:19 pm on November 14, 2038, by the TRD Testing Apparatus built by Eloise Lundberg, PhD. Take the subway.”
She couldn’t believe her eyes. She had, or rather, would someday, send a message back in time to herself. She reread the date on the screen. That was today! In fact, it was in about an hour, she realized, triple-checking her watch.
But just receiving the message wasn’t the end of her experiment. In fact, it was only the beginning. She picked up her tachyon emission device, which she used for testing, and, trembling, took the tachyon source out and smashed the rest of the device on the floor. Without the apparatus, she wouldn’t be able to send a coherent message back in time to herself. She had just prevented the message she had received from ever being sent.
She looked down with melancholy at the broken machine on the floor. It was part of what she had spent so long to build, but, she reminded herself, it had served its purpose. Now, its job was to never work again.
She had nothing left to do at home for the day. In fact, she decided to go out, to further ensure that she wouldn’t be able to create the message she had received. She decided to go to the diner in the city; it was her favorite place to eat, and her boyfriend’s apartment was in the building next door.
She left her house, locked the door, and headed towards the bus stop. It was beginning to get dark. She only had to wait three minutes for the bus, but traffic heading into the city was bad; there had been an accident on the bridge. She kicked herself for not having taken the subway, realizing that the other Eloise, the one who sent the message, must have heard about the accident on the evening news. But that was a different person, somewhere indescribably far away.
She finally got off the bus at 6:26, and walked two blocks through the cool but musty city air until she reached the diner. She pushed open the door and was greeted by Arnie, a waiter who had seemingly worked there forever. He knew Eloise’s favorite dish: blueberry pancakes with sausage links. She sat down in a booth by the window.
“How’s it goin’ Dr. E!” he said. “The usual?”
“Hey Arnie. No, I think I’ll have Eggs Benedict, if that’s alright.” She didn’t feel like pancakes tonight.
Arnie looked a little surprised. “Sure, sure, that’s fine. And coffee?”
“Cream and two sugars, right?”
“No, I’ll take it black, like usual.”
“Like usual?” Arnie was taken aback. “Eloise, I’ve known you for years; you always take cream and two sugars.”
“You must be thinking of a different Eloise,” she said, smugly. She looked at her watch and chuckled. It was 6:32:04. Arnie went off to fill her order while she watched the seconds tick by. Seventeen, eighteen, nineteen, twenty. She looked out the window, satisfied.