Posts Tagged ‘quantum computing

What are the projected risks of Quantum Computing?

Although there are many proposed benefits anticipated from quantum computing, there are also potential risks. Among these are the following:

  1. While advancements in security will be welcome within the IT community, there is a possibility of an uneven distribution of adoption of the new technology. If some firms adopt quantum computing and others do not, those without these systems will be vulnerable to the security threats.
  2. Conceptually, it is believed that with quantum technology we will be able to build microscopic machines such as a nanoassembler, a virtually universal constructor that will not just take materials apart and rebuild them atom by atom but also replicate itself. The good news of this self-replication machines means that these nanomachines will cost nothing to build and eventually make any products we might desire at zero cost. The bad news is that these HAL-like computing brains with capabilities exceeding those of humans, could redesign and replicate themselves at no cost, other than the loss of human dominance.
  3. Quantum computing will instigate rapid changes in computing and corresponding modifications to human life, at a time known as the point of Singularity. When that day arrives, some futurists fear that quantum computing will cause things to change so fast that it will be impossible to predict what will happen next. Or, there will be “a developmental discontinuity, an ultimate event horizon beyond which predictability breaks down totally.” It sounds as terrifying as those scenarios in a science fiction film; theoretically, nevertheless, it is the risk that quantum computing might eventually lead us to.

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Entanglement of Quantum Systems

According to quantum mechanics an outside force acting on two particles of the quantum system can cause them to become entangled. The quantum state of this system can contain all positions of spins (internal magnetic moments) of each particle. The total spin of the system can only be equal to certain discrete values with different probabilities. Measurements of total spin of certain quantum systems showed that positions of spins of some particle are not independent from others. For such systems, when an orientation of a spin of one particle changed by some reason, an orientation of a spin of another particle changes automatically and instantly. The laws that that have been developed so far about the speed of light are disobeyed in this case, because the change in an orientation of a spin happens immediately. At least there is hypothesize to use this phenomena for quantum computing.

It is well known that a speed of communication is limited by a speed of light as nothing can travel faster than the speed of light. The question is how particles of the quantum system communicate when they change their spin orientation and consequently their vector states. Famous scientists spent a lot of time discussing this issue. Einstein’s idea that some unknown “hidden parameters” of quantum system were contributing to this effect has been rejected theoretically and experimentally.

This is one of the example showing the difference between classical and quantum realities. This effect of the quantum system explains a lot of aspects of the nature (f.e. chemical characteristics of atoms and molecules) and is proved by the experiments.

“In fact, theories about entanglement have led scientists to believe there could be a way to speed up computing. Even today’s computers are nearing a point at which their speed is being limited by how fast an electron can move through a wire – the speed of light. Whether in a quantum or traditional computer, entanglement could blow past that limit.”

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