The Strings of the Universe

It’s the middle of summer; everyone is outside, making the most of the warmth and breeze. Children are frolicking, families meandering. Ice creams and cold drinks are passed around to beat the heat. Shallow inflatable pools, sandboxes, trampolines, and the like are brought out for entertainment and to encourage young Ansh to spend more time being active. 

Young Ansh sits on the steps leading up to his house, thinking. He’s the only child not partaking in summer activities at the moment. Instead, his eyes are set on a trampoline set some distance away, where his friends are jumping with all their might, trying to touch the stars.

He wanders into his house, still deep in thought, making hand gestures in an attempt to visualise his problem. He enters a room currently occupied by his grandmother, Dr. Neha Narang. The renowned physicist sits comfortably in her plush armchair while she glances through one of the many scientific journals piled up next to her. She looks up and is surprised to see Ansh. 

She asks him, “Ansh, why are you inside on such a wonderful day? It’s not like you to miss out on playtime. You look troubled— is something wrong?”

Ansh looks up at his grandmother, frowning. Then he lights up, exclaiming, “Nani, you teach things about science; the earth, wind, trees, stars, and everything, right?”

“You’re correct, sweetheart. I teach a science known as physics, where we explore the world around us!” she replies with a smile. 

“Cool! Do you know about trampolines? They are so soft and bounce when you jump on it! It is so much fun. But…” He trails off, frowning again. “I wish the ground was a trampoline. Why is the floor so hard and boring? Why doesn’t it move and sink around me? Is it because the wind is not strong enough?” He questions, sadly. 

Neha listens intently, inspiration popping into her head. “Oh, but things do move and sink around everyone and everything! We can’t see it, which is sad, but it happens.”

Ansh is curious; he sits on the floor close to grandma. “I don’t understand. What do you mean?”
Neha looks at Ansh. He’s only eight, but he’s inquisitive and smart, she thinks. There was a story beginning to weave in her head; she figures she can explain anything if it resembles one of those tales he loves so much.

She begins.

Every activity around you — from you switching on the fan to get rid of the heat, to earth revolving around the sun — is brought to action by the combined efforts of four friends. These four friends are responsible for almost everything in the universe. Adults in white coats—scientists like me— sitting in their labs, named these four friends as the four fundamental forces.

One of them is Gravity or the force that helps keep us, the earth, the solar system, and the entire universe in place. The next is the electromagnetic force, which helps in the interactions of almost all the materials around us. There’s the Weak Nuclear force, which is very important for the fusion reactions similar to those happening in the sun. Finally, there’s the Strong Nuclear force, which binds together the small particles which constitute most of the objects around us.

The twist in the story comes with the discovery of these forces. We didn’t discover them huddled together, making the universe function. We found them one by one until recently we realised that all these good, hard-working forces are actually very close friends! This realisation didn’t give rest to our brains— in fact, it made us work even harder. Now that we understood that all these forces are essential for survival, we started researching how they work. What we found was that these forces or interactions take help from microscopic particles in ‘carrying’ the force. 

Everyone was content and happy until one day, a person named Einstein said that gravity does not work like the other three forces. He explained that space and time in which we move works like a fabric, a long piece of cloth. Now, imagine if you hold a cloth from both ends and put a heavy ball in the middle, you’ll see the fabric curving around the ball. Similarly, in the case of the trampoline—when you stand on it, there is a dip; the area curves around you—the area shifts and still curves around you when you walk around it. If there are any smaller objects near you, they are temporarily drawn into this warp you create.

These curves and warps and dips communicate or ‘carry’ the force of Gravity. This got other physicists into thinking, what if they could use this concept to explain some mysteries? So they tried to understand the workings of other forces in this manner of warps and curves.

What followed next was scientists claiming that apart from the three dimensions— that is, apart from movement along the three axes and through time, there also exist other dimensions. However, we need more space or dimensions to create a system of curves and warps for other forces to function. Here comes the most interesting part— where do you think these dimensions are? Can you think of alternative ways of moving in space apart from left-right, upwards-downwards, and forward and backward? 

There is a pause. “Hmm, what about… diagonally? Zig-zag?” Ansh questions. Neha laughs. 

“Moving diagonally is a result of using our dear friends— the three dimensions— and making them work together. In simple terms, diagonal is the result of the forward/backward and left/right dimensions, even the upward/downward dimension, working at the same time. 

Think about it this way— if you are walking forward and I pull you a little to the left or right, it’s diagonal! Isn’t it amazing how everything we do can be explained in simple terms? I’ll show it on paper when you’re older. There’s mathematics in everything— it’s beautiful.” Neha trails off, realising she lost Ansh while she was digressing into a mathematical daydream. 

She clears her throat and continues. “Although you’re correct, my question was whether you could think of a way to move in space that doesn’t involve our friends, the known dimensions.” She can almost feel the gears in his brain turning; he watches his hands move this way and that, trying to figure out an answer. He gives up, looking up at her imploringly. 

She neatly rolls up a sheet of scrap paper lying next to her so as to have an extremely thin and long cylindrical or string-like object and continues her story.

Look around you; we see the world in a certain way. The earth is big; a toothbrush is small. What if we looked at the world from the perspective of, say, an ant, though? Imagine it. Suddenly, there are new ways to move around anywhere; new ways to see things that we wouldn’t normally see. Scientists visualised this and found a new and exciting approach to better understand the relationship between our close-knit friends, the forces.

Look at this small cylinder, for example. If you see it from a distance, you might think that it is only one-dimensional. But imagine an ant walking around it. For the ant, the size of this same cylinder is huge. The ant is so small that it can access all dimensions of this object. It can move through the length of the cylinder—the “regular” dimensions, and also move in a clockwise or anticlockwise direction on the surface. That is the ‘curved’ dimension, and our ant is moving along it. She uses the rolled-up cylinder to help Ansh visualise and traces the circumference of the sheet with her finger to demonstrate the movement of the ant in a circular path. She interrupts the story to explain that there are particles smaller than dust—atoms, and molecules, before continuing to make it easier for him to follow.

Upon more research, we discovered that there might be two types of dimensions—one which is big enough for us to move around them, and one so small that we can neither see them nor move around them. All the scientists jumped with joy with this discovery. No no, don’t make that face, we are not loony old people. We rejoiced because of what it meant for science. It meant that the additional dimensions that we need to explain how the other forces work in the same pattern of warps and curves as Gravity— might be curled up in very microscopic shapes, much smaller than atoms. That’s the reason we haven’t been able to see them. Neha pauses. Yet. 

They figured if looking through the perspective of an ant would lead to so many ideas, what if they went further? What if they magnified particles smaller than dust—the atoms and molecules—and saw things from that perspective?

At this realisation, all the hungry brains of my fellow physicists, which feed on curiosity, got to work. Obviously, we can’t move around this tiny cylinder the same way as an ant, because we are massive beings in comparison. Now, imagine those atoms and molecules; we can’t even see them with our eyes, but what if many small dimensions exist within these small, small particles? There are infinite possibilities! 

Upon applying this concept of extra dimensions into what we already know about physics, we found out that they didn’t go hand in hand. The weight of small particles like atoms, and electrons that are present within atoms, didn’t match with the weight we have calculated through other experiments. This made the scientists very confused, and they thought maybe the theory is not right; perhaps it is just our imagination running wild and there are no actual dimensions present all around us. It was disappointing.

Okay, no need to be mad at your Nani, I didn’t tell you a pointless story. There’s more to it. A few years ago, scientists found a way of making the theory of additional dimensions work. But they renamed it ‘The String Theory’. 

This time, we focussed on the small particles which make up the objects around us— electrons and quarks. These are the elements even smaller than atoms! Earlier, we believed that they are the smallest objects known to us, and we can’t cut them into smaller pieces. Now, our brand new string theory says that these tiny particles are essentially made of very small strings that keep vibrating in different patterns. With this theory, the problem of the weight of the smallest particle not matching with the calculated weight gets solved.

Suddenly Ansh lights up, visualising this. He asks, “What are these strings? Are they similar to those slimy worm toys I have? Or do they look like noodles? Do they stretch?” Neha laughs, “No, unfortunately, they are neither worms nor noodles; they are vastly different. But they always keep on jumping and moving very energetically, just like you.” Much to Ansh’s dislike, Neha rustles his hair and continues.

These strings are like dancing filaments of energy; they look like vibrating strings used in some instruments like guitars or cellos. Just like the strings in these instruments vibrate differently to produce different tunes, our small, powerful energy strings vibrate in different patterns to make various particles which make up many objects around us—Neha gestures around her.

This theory is also nicknamed as the ‘theory of everything’ because the basic element of all particles is the same—the strings. Imagine it like this— all the houses in our neighbourhood are different, but they’re all made of bricks. The main element vital to the construction of homes is the same. So all the forces and the particles which they use in the microscopic level to ‘carry’ them are made of these strings. 

Now, you must be thinking where are other small dimensions in all of this. Well, it turns out that string theory is very self-aware. When we sat down and worked with numbers revolving around our theory, it told us, ‘It won’t work until you give me some space in the form of different dimensions.’ 

So physicists thought, okay, we’ve got this covered, we have some dimensions lying around, you can have them. At this, the theory dropped another bomb. The equations of the theory suggest that we need at least ten dimensions plus the time dimensions for it to work. That’s SIX additional dimensions! In some calculations, the dimension count goes as high as 26! The scientists had their hands tied; we also really, really wanted to see what the strings did with all the dimensions. So, we complied.

We gave the string theory its dimensions, and it gave us the potential of unifying all the laws, forces, and formulas of physics, into one fundamental hypothesis. Mysterious connections and unanswered questions, solved! Well, theoretically.

At this, Ansh scrunches up his face, confused, and asks, “That is great. But where did the small dimensions go?” Neha smiles at his curiosity and answers, “The dimensions are still here, but they are wrapped around each other. These dimensions fold in within each other, giving the strings a space to vibrate. When you move around, you are engaging and crossing these dimensions, but they are so small that you can’t see them. 

You asked me why the ground doesn’t wrap around you; the answer is that it does! We can’t see or feel it, but you can feel this!” Neha bends forward and scoops Ansh in her arms, engulfing him in a hug. Ansh sinks into it, giggling. “You’re wrapped around me, but I still have space to wiggle in your arms. String theory!” 

Neha bursts into laughter at this, planting a kiss on his forehead and releasing him. “Exactly! Aren’t you a smart kid?” She is slightly awed at how quickly he picks up what she explains. “Ansh, that was a great example. There isn’t a lot of practical proof like this, yet. We could be time-travelling, and you’d be able to see the world as a trampoline; if only we could find some proof. It’s everyone’s dream,” she finishes, wistfully.

Ansh’s eyes widen at the idea of an earth-trampoline and time travel; two things he loves. He wants to see them with his own eyes, no matter what. “Nani, I’m going to go find proof, and we will make everyone’s dreams come true!” He stands and points at himself proudly. 

“I don’t doubt that, sweetheart. Now, go back to the trampoline and have fun; maybe you’ll even find proof there,” Neha replies. She honestly believes in her grandson’s abilities; if an earth-trampoline acts as motivation, so be it. 

He smiles and rushes out of the room bouncing, with his arms flying. His dilemma solved, he goes back to play care-free, but from now on, doesn’t stop visualising what he had learnt. He sees the dimensions laid out as he vies to touch the sky while bouncing high. He sees them when he attempts backflips to recreate the circular dimension. He sees them, years later, when he’s accepting his degree in the field of physics, forever yearning to find proof of something he never stopped believing in.

Written by Lavya Joshi and Ishita G for MTTN

Edited by Kaavya Azad for MTTN

Featured Image from Paper Boat Creative