The crux of a quantum computer, the technology allowing substantial improvements in calculation speeds, is a qubit (contraction of quantum bit). This tiny computational node is elusive yet important. But, you may ask, what is a qubit? To understand a qubit, let’s first consider its classical analogue, namely a bit. A bit is the basic unit in modern computers which takes the form of either a zero or a one, and it can be used to represent everything… your accounting documents, your favorite programs and even pictures of your dog eating chocolate ice cream. Most importantly, a bit is a piece of logic which can be compounded to represent all things digitally. Now, we have bits and bits can represent everything, so why bother with qubits?

A qubit (quantum bit) is far more complex than a bit. But a qubit can calculate many problems much faster than a bit. A bit can be on or off. A qubit can be on, off or both. How strange!

Well, it’s complicated but it has to do with calculation times. I will give you a simple case so that you can appreciate the need for quantum computing. Lets say we have a program that makes  operations before finishing which is common in many engineering and scientific applications. For small N, say 100, and assuming for the sake of example that the computer does a million million operations each second, the program would run for about 40 thousand million years, which is the same order of magnitude as the age of the universe! Clearly as mere mortals we do not have this much spare time. But a quantum computer will fix this. By having multiple states for a qubit, a quantum computer can do the same calculation in minutes or even seconds. Now that is worth having.

A tough problem (intractable) can grow in computational time quite quickly. You may have to wait a few million years to get your answer!

So, we have learned about the how, and the why, now let’s solidify the what. What can you do with a quantum computer? Well you can model perfect pharmaceuticals, understand atomic processes and crack secure accounts… and that is just scraping the surface of possibilities. The last scenario is quite serious, and hence there is a strong incentive to understand, and build, a quantum computer from various stakeholders including governments. So then, what about science fiction? Well the answer is in the what. Perfect pharmaceuticals… perfect monsters. Perfect atomic processes… perfect weapons. Perfect code cracking… perfect espionage.  You see, by understanding technology, science reality can be transformed into science fiction which can then penetrate society and become part of our culture. If you can imagine it, then perhaps it can exist. So I leave you with a challenge. How would you use a quantum computer to turn science reality into science fiction?