Chutney or no chutney. Meat or no meat. Warm or not warm. These are all questions we ponder when purchasing samosas. But what factors play into making our choices when selecting this intricate delicacy?
To chutney or not to chutney: these are our only thoughts when perusing the box in Leacock lobby. Logically, one could say that if a samosa has chutney, it is then a chutney-filled samosa. If it doesn’t have chutney, it is equally logically obvious that the ‘mose is chutney-less. But chutney is not the only factor in play. Now let’s throw the meat variable into this potato mess. If we know our samosa has chutney and no meat then we would have a meatless chutney-filled samosa. With these two options, we have a total of 2^2 (or 4) options of samosas. As we slowly gather more information about our samosa in two state information (chutney/no chutney, meat/no meat.), we could add more categories: chicken or no chicken? Beef, or no beef? Each variable would build a more complex samosa system. If we know a samosa has meat, but not chicken or beef, we could have a pork samosa. We wouldn’t know the exact meat but, because we have narrowed our options, we might have a better idea of our samosa.
But writing out every single bit of information is tedious. Let each piece of information (chutney, meat) be referred to as a ‘bit’. Let our chutney-filled samosa be labeled as ‘1’ and our chutney-less samosa as ‘0.’ The first digit will represent the bit for our chutney information and the second will represent the bit for our meat information. So, we can even go further and have a meat and chutney-filled samosa represented as ‘11’, and a meatless chutney-filled samosa as ‘10’ and build on from there.
If we just make the most basic samosa, with the least effort, our samosa would have neither any chutney nor meat and we would express it as ‘00’. In order to have to chutney, we have to exert our energy and grab our straws filled with chutney and put that chutney goodness inside the samosa. To put meat in a samosa, we have to use energy to cook the meat and place it inside the samosa.
In traditional computing, it’s safe to say that if we have ‘01’, a chutney-less meat samosa, upon taking a bite we’d expect to discover a similar flavor profile. If we know that our first bit tells us that we have no chutney, that is definite.
…But what if we didn’t? What if we started with a ‘01’ samosa and by the time we took our first bite we suddenly had the opposite, ‘10’, a chutney-filled meatless samosa? Here, we have the idea of a samosa which is constantly changing states. Welcome to quantum computing. The difference between a static and dynamic samosa sums up the important difference between traditional computing and quantum computing.
To get a better idea of this difference, let’s look at qubits, a unit of information in quantum computing comparable to a bit in traditional computing. We said before that a samosa’s first bit can be either 0 (no chutney) or 1 (chutney). This bit only contains two states. A qubit however, can be both 0 and 1. It sounds weird to think of a samosa with and without chutney. But imagine when filling your straw with sweet chutney, air bubbles start to form. They could be shrinking or growing so we would have more or less chutney, respectively.
Before our bit would either be 100% 1, 0% 0 (chutney) or 100% 0, 0% 1 (no chutney). But now, our qubit is in superposition; the idea that we can be in both states at once. We can be anything from 85% 1, 15% 0 to .00001% 1, .99999% 0. We have infinite possibilities.
If we had 2 qubits, we would have potentially 4 superpositions: ‘01’, ‘00’, ‘10’, ‘11’. We can create four different types of samosas from only two pieces of information, whereas before we would only have one samosa from knowing if it definitely had chutney and/or meat.
“So, if our samosa can be either of these four options then which one do we have?” we might ask. Well, we can only tell by taking a bite or ‘observing’ the samosa. When we observe our samosa all the qubits collapse to one state and we will taste either only chutney or no chutney at all. All meat or no meat.
Why would we even want these qubits if all it gives us is uncertainty? Why not have bits that allow us to definitely know what we are going to taste? If we let our 3rd bit be chicken/no chicken and 4th bit be beef/no beef then to say our 2nd bit is 0 (meatless) would automatically mean that our 3rd and 4th bit would also be 0. In layman’s terms, we can’t have chicken or beef in a samosa if we already know it is meatless. With qubits we wouldn’t have to put our samosa through this logic test since the qubits are in superposition containing both states (like meat and not meat). We could have any of 2 * 2 * 2 * 2 = 16 combinations of qubits that would give us samosas that would be meatless yet have chicken and beef at the same time.
Odd to conceptualize, but quantum computing allows us to use the same number of qubits as number of bits and create different types of samosas exponentially faster. We can create more complex systems with less information, much like we can create more samosas with less qubits than bits, using superpositions. So, if your friends wanted to be able to create chicken samosas for themselves then you could provide your four qubits to them and they could make the samosa of their pleasing.
On top of superposition, what would you say if I told you that if you took the chicken out of your samosa (making it chicken-less) then your friend eating his samosa would suddenly discover that there’s no chicken inside anymore? It’d be a good prank for sure, but how could your samosa’s chicken qubit be somehow connected to your friend’s chicken qubit? This idea that some qubits have a connection or a high correlation with others is called ‘entanglement’ in quantum computing. If we observed our chicken qubit at one point and saw it was 1 then we would know that, at that exact moment, the entangled chicken qubit would also measure to 1. Essentially,if the chicken qubit in our samosa is entangled with another chicken qubit in another samosa, we can tell how the other chicken qubit will change instantaneously as our qubit changes. A paper published by the University of Waterloo describes entangled qubits such that they “can ‘dance’ in instantaneous, perfect, unison, even when place at opposite ends of the universe”, so distance does not affect this relationship.
With entanglement theory, we can fathom the ways in which samosas are connected (through chutney, meat, etc.). If for example, we found that all qubits in one samosa were entangled with all qubits in another samosa, then both samosas would be potentially identical and we wouldn’t have to work with that other samosa.
Quantum computing through superposition and entanglement allows computing to be exponentially faster and help us solve problems at speeds that would take regular computers years by comparison. Now, for some real life applications of this scenario: as these theories are based on quantum physics, a deeper understanding of quantum computing can help us find solutions to related issues. This can be applied to protein folding, and the design of more effective pharmaceuticals.
Regardless of where quantum computing can take us, hopefully when I take a bite out of my next samosa there won’t be anything inside of it but warm potatoes, and, obviously, sweet sweet chutney.