What is a quantum computer? This is not something that is easily answered, Einstein himself had trouble understanding certain things that happen in the quantum realm. When we say quantum realm, we refer to the sub-atomic level, where we look at what atoms are made of. These sub-atomic particles have some strange properties that can only be explained by theories today, with machines like the hadron collider we are hoping to turn some of those theories to fact and other theories like the multi-verse might never be proven but do have enough data pointing towards a strong possibility that it does exist.
When we look at these particles on a sub-atomic level they seem to vanish and reappear in a different spot without any connection what so ever. This is what is referred to as a quantum leap and would be similar to you just vanishing from Toronto, appearing in Paris and continuing to disappear and reappear all across the planet. Although this happens on a sub-atomic level we don’t notice it on the larger level for some reason where everything seems to exist in a certain part of space and is constantly there, hence the confusion.
It’s these particles that we are trying to make use of inside of a quantum computer. Today’s computers use a bit, which is either a 1 or a 0 and combine them in groups to create sounds, colours or even the alphabet etc. Something that we call a byte consists of 8 of these 1’s and 0’s, they give us a method of counting from 0 to 255 with all the combinations they can have but only one of these combinations can exist at one time. This same principle applied in a quantum computer means that same bit can be both a 1 and 0 at the same time, therefore if we combined them in groups of 8 we would have a value that exists between 0 to 255 but all at the same time.
To give a more practical example that would be easier to understand, picture a hedge maze with 100 possible routes, a single starting point and only one way out. If you were a traditional computer you would try your first possible option and if that failed you’d start again and try the next combination, this would continue until you discovered the right path. This could possibly happen on the first try or the last one (100th) but more than likely would fall somewhere in between like the 75th for example. Now picture a quantum computer where there are a 100 of you, one for each combination and each one tries a different route with only the successful one coming back as the right answer. This means no matter how we changed that maze it would give us the right answer on the first try and if the maze got more complex with 1000’s of combinations it wouldn’t matter as the quantum computer would again do them all at once and give us the correct path on the first answer.
Even though today companies like D-Wave out of Canada built what is considered a quantum computer the computing power isn’t where it could and probably will be one day. This is believed to be accomplished somewhere in the next 10 years by the skeptics, so optimists are hoping to achieve this by tomorrow. This means the computing power at our disposal is set to drastically increase and although it might not really matter when doing simple calculations like 5+5, it will make a huge difference when simulating things like the weather patterns on our planet, effects of global warming or even answer questions we have regarding the universe itself. More than likely it would also introduce the possibility of a very high level of artificial intelligence as well. One whose intelligence would leave all the smartest people on the planet in the dust.