Quantum Supremacy; Michio Kaku; 2023; 300 pgs; notes, index

The world seems like a pretty messed up place at times. And I sometimes wonder if it can ever get better.

Quantum computing may be the answer, but it comes with a warning… it can be used for evil.

I cannot tell you how it works because I do not understand how it works. In simple terms, a QC can perform calculations that would take a modern computer millions of years to do. One evil use of QC would be to hack into any system in the world in seconds. A good use would be to solve the world's energy crisis.

When I was in university studying computing, things were very primitive. A subject that I always disdained was sorting, mostly because it was obvious to me that computers would get faster so quickly that even a bad sorting algorithm will work almost instantaneously. But the underlying issue of sorting is that it takes time, no matter how you slice it. There are many tasks that are similar to sorting that chew up all the cycles they can get. For example, predicting the weather. 


I can only give you a sort of analogy to how QC works. Imagine you have a large number of sticks of varying lengths, and you want to sort them from longest to shortest. A computer can do this task very fast, allowing you to then arrange the sticks in any way you please based on length. But a man can do the chore in a single operation… just grab all the sticks in one hand, hold them loosely, and them bang the hole lot onto a table. You can now easily remove the tallest stick, and then the second tallest stick, and so on. This is sort of how a QC works. The sorting problem is of a class called NP complete functions that take time that is related to the problem to be solved (things to sorted, for example) in a polynomial sense.


One problem in biology is protein folding. A protein is a long chain of amino acids that fold up in a specific way. The final shape of the protein determines how it will react chemically in the body. QC could calculate all the different ways to fold the protein, and how it will react inside your body. Note I said "your body", not "a body". QC can do that too. That means that, among other things, cancer can be beaten. 


I will not go into the list of issues where  QC can be used. There are a lot of them. I found this one the most fascinating.


We learned about photosynthesis in grade school. I always assumed we knew how it works, but we do not. Not at the quantum level. We can reproduce photosynthesis in a lab after a fashion, but we are very inefficient when compared to nature. A solar cell is only about 1% as efficient as a leaf in terms of converting light into work. QC could crack that problem. If a solar cell can be made that is as good as a leaf, all out energy problems will be gone. The abundance if energy  would allow us to remove all the carbon we have been spewing into the atmosphere, and reverse global warming.


QC will likely play a major role in creating a working fusion reactor. QC can also address starvation around the world. Plant food (fertilizer) can be synthesized much cheaper than we do it now. QC will tell us  how.


I liked this book. It is good summary of the history of computing and a good read. And I like that is paints a better picture of the world's future than most people would have thought possible.          

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