"Google said it has achieved a breakthrough in quantum computing research, saying an experimental quantum processor has completed a calculation in just a few minutes that would take a traditional supercomputer thousands of years."
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Quantum computing has been in the news a lot.
It is supposed to revolutionize computing, eventually making computers vastly more powerful.
https://en.m.wikipedia.org/wiki/Qubit
https://en.m.wikipedia.org/wiki/Quantum_computing
The basic premise of 'building a better processor' is that it
a) will have more than two states for its memory bits.
A regular computer has just two states. So one bit can have two possible values, 1, 2
two bits can have four possible values, 11, 22, 12, 21
four can have sixteen, 1111, 1112 , 1121, 1122, 1211, 1222 , 1221, 1212, 2111, 2112, 2121, 2122, 2211, 2222, 2221, 2212 etc.
If the bits had 3 states then 1 bit would have three, 1, 2, 3.
two bits would have nine, 11, 12, 13, 21, 22, 23, 31, 32, 33. etc
If you were able to get a 'bit' with a high number of states then the processing power would increase rapidly. A computer using a 'bit' that had hundreds of states would not need that many bits to hold a large amount of information.
If a bit has 100 states then one bit has 100 possible values.
Two bits would have 10,000 values
Three bits would have 1,000,000 values etc.
So a computer with just a few hundred of those bits would store a vast amount of data. The problem would be reading and writing the elements of data to and from the '100 value bits'.
The premise of 'quantum computing' specifically is that the number of states cannot increase faster than the size of the basic 'bit', for example that you can't take ten items that each have two colors and combine them into one item with 500 colors. You have to start with something that is small and starts with a lot of states.
What is something that has many states and could be used? There would be a way to make anything into a computer. You could make a chemical computer that used different combinations of elements as multi value bits, but you'd have to figure out a way that made it practical.
b) not lose computing power due to physical limits imposed by whatever is used as the replacement 'bit'.
If you used a dictionary as the 'bit' then each bit would have tens of thousands of states, a computer with ten bits would be able to calculate almost anything a person could want to calculate. But dictionaries are bulky and there isn't an easy way to arrange a circuit board with several dictionaries having those dictionaries interact near instantly. Plus you'd need to have a 'dictionary reader' and a dictionary writer' that could rapidly 'read' and 'write' the one character 'word' in a way that the final result was faster than using binary digits to compute.
So the objective is not necessarily best met by using the quantum states that are referred to in quantum computing. It's very possible that there is some other way to read and write a multi value digit which uses the number of possible values per digit to 'outmuscle' the physical limitations of that particular type of digit.
An example might be using 'large' objects that have numerous values, and using, for example, light instead of electricity to interact, read and write, between those objects.
Some people like things to be electric. A simple can opener has been made into a complicated electrical tool with many parts, and to many it seems like an obvious improvement, even though it's silly. The focus often is not on using 'technology' to improve something but on using 'a specific technology' to prove or reinforce something regarding that technology.
~ In Progress