No time machine needed
by Nic Cullinan
Julia had a problem. She had to find out how to time travel, and she had to do it fast. The stakes were high – if she couldn’t prove to Emily that she could travel through time, then she would lose a dare for the first time ever. Every Friday, Julia and Emily made a dare with each other after school. Last week it was Julia’s turn to do a dare.
Emily had said “I dare you to build a time machine!”
Julia had done ALL of Emily’s previous dares and wasn’t about to lose her record now.
“I accept your dare. By lunch time on Monday I’ll prove to you that I can travel through time. This will be easy.”
But Julia wasn’t sure that it would be easy, it sounded hard. As soon as she got home, she watched all of her favourite sci-fi shows that included time machines, and read all her favourite books in which the main character travels through time. But the weekend had gone so fast and she still hadn’t discovered how to time travel. She fell asleep on Sunday evening curled up on the couch, book in hand, still trying to understand the mystery of time. Her dad had to carry her to bed, and that night she dreamt of travelling through the stars.
She was in a grumpy mood on Monday morning as she ate her egg on toast.
“This is the first time I’ll lose a dare with Emily. I just didn’t have enough time to figure it out.”
But then, just as she was about to take another bite, she devised a cunning plan to win the dare.
“I don’t need to invent a time machine now, I can invent one in the future. Then I can just travel back to now, and give myself the time machine.”
In that instant she stopped being grumpy. She didn’t know what was going to happen, but was excited to find out.
She grabbed an extra piece of egg toast and dashed out the door, yelling goodbye to her dad as she went. She knew a great spot to do time travel. As she reached the top of her favourite hill overlooking the neighbourhood, there was an astounding flash of light in front of her as a glowing figure stepped out of a rapidly closing portal. The figure was tall, dressed in a flowing blue cloak, and had a silver pocket watch hanging from her top pocket.
Julia gasped as the figure smiled and took the toast from her outstretched hand.
“Hey Julia, it’s me, Future Julia” said Future Julia “Thanks for bringing me toast, I always appreciate how thoughtful of others you are.”
Julia could hardly believe that her plan had worked so well.
“Are you here to give me my own time machine?”
Future Julia had already taken a big mouthful of toast, so had to chew for a bit while speaking.
“No, I’m not here to give you a time machine, I’ve only got one and I need it to get home. But don’t worry, I’m here to do something even better. I’m going to share some of the mysteries of time, so one day you can make your own time machine. Grab my hand and let’s explore the cosmos!” Julia looked around the hill one last time. She was finally ready to do some time travelling. She grabbed Future Julia’s hand and immediately felt her body floating as another flash of light teleported them.
Looking around, Julia found herself in space. In front of her was a dark patch with nothing in it. Around it swirled orbiting stars and dust clouds. It was so big that she felt like a little mouse in comparison.
“This is the black hole at the centre of our galaxy” said Future Julia “Its gravity is so strong that not even light can escape”.
Julia could feel the gravity pulling on her feet, like wearing shoes made out of bricks.
“Its gravity is so strong – will we time travel if we go inside it?”
Future Julia shook her head “If we go inside we’ll be squashed like a pancake, but you can travel into the future just by staying near it. Anything with a large mass slows down the flow of time near it. The closer you are, the slower time passes for you compared to everywhere else. This black hole has one of the largest masses we know about. For every minute we spend here, thousands of years pass on earth, even though we feel like time is passing normally for us.”
Julia took out her phone to check the date and sure enough, decades were flying past like seconds on her calendar. The year back home was no longer 2020, it was 5020!
“This happens wherever you find gravity, even on earth. Someone who lives next to the beach is close to the mass of the earth, so they will age more slowly compared to someone living on a mountain.”
Julia crossed her arms. Time was stranger than anyone had explained before. Instead of a single universal time that was the same for everyone, it seemed like every place in the galaxy experienced time slightly differently.
“If people on the beach age slower than people living on mountains because of gravity, does that mean my feet age slower than my head?”
Future Julia gave her a big thumbs-up “That’s precisely how it works. Your feet are younger than your head by a miniscule amount of time. The difference is so small that you’ll never notice it, even if you live to be 100 years old.”
Future Julia took her hand again “Get ready, we’ve got one more stop before I take you back home”
In another flash Julia found herself in front of a giant ball of burning fire.
“This is the sun” said Future Julia “It shines light down to earth and makes life as we know it possible.”
Julia was amazed at how bright it was. The surface was constantly shifting as hot plasma blasted out. She pulled a hat from her backpack and jammed it on her head so she wouldn’t get sunburn.
“It’s so bright – how does this help me with time travel?”
Future Julia pointed at a pale blue dot in the distance “The earth is that way. Even though light is fast – it’s the fastest thing in the universe – it still takes time for the light from our sun to move through space. It takes 8 minutes and 20 seconds for light to travel all the way to earth.”
Julia thought about this for a moment “But if that’s true, then when we look at the sun, we’re actually seeing what the sun looked like 8 minutes and 20 seconds in the past?”
Future Julia gave her a big smile “That’s exactly right - when you look at the sun, you see its light from the past. If you look at things even farther away than our sun, you’re seeing light from even further in the past. Some of the starlight that you see in the night sky is actually from millions of years ago.”
Julia was beginning to understand now. Even though light is fast, it still takes time to get from one place to another. When she looked at the stars, that light might have taken millions of years to reach her. She could see what stars looked like in the past without having to time travel at all. In fact, every day she was seeing light from the sun that was from the past!
Julia decided to see if she could feel time. She closed her eyes as they floated in front of the sun. Even though nothing happened, she could feel that time was passing. She was a time traveller. She turned to Future Julia, who was preparing to take them back.
“Do you really have to go? There’s so much I still don’t know. If I don’t bring back a time machine, I lose the dare with Emily.”
Future Julia put her hand on Julia’s shoulder “Don’t worry about the dare. If a dare isn’t fun, then it’s not worth trying to win. When you set out to do something, there’s no guarantee that you’ll succeed. As long as you learn something new, then you win every time.”
The two shared a hug, and in a flash, Julia was back in front of her school. She checked the clock on her phone – school was just about to start. Even though she was going to lose the dare, she still felt really good. She’d learnt some new things and was more curious about the world than ever. She couldn’t wait to see Emily’s face when she found out that her head was older than her feet. Besides, it was Julia’s turn to choose the next dare, and she was going to dare Emily to build a spaceship.