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Quantum Computing Without Qubits
An anonymous reader shares this interview with quantum computing pioneer Ivan Deutsch. "For more than 20 years, Ivan H. Deutsch has struggled to design the guts of a working quantum computer. He has not been alone. The quest to harness the computational might of quantum weirdness continues to occupy hundreds of researchers around the world. Why hasn't there been more to show for their work? As physicists have known since quantum computing's beginnings, the same characteristics that make quantum computing exponentially powerful also make it devilishly difficult to control. The quantum computing 'nightmare' has always been that a quantum computer's advantages in speed would be wiped out by the machine's complexity. Yet progress is arriving on two main fronts. First, researchers are developing unique quantum error-correction techniques that will help keep quantum processors up and running for the time needed to complete a calculation. Second, physicists are working with so-called analog quantum simulators — machines that can't act like a general-purpose computer, but rather are designed to explore specific problems in quantum physics. A classical computer would have to run for thousands of years to compute the quantum equations of motion for just 100 atoms. A quantum simulator could do it in less than a second."
Look in the sky, see the flock of starlings?
The dark clump of birds that you can see will dart around, sometimes here, sometimes there. It can fly west and yet clump east, time-travel! Must be negative time! Sometimes simultaneously appearing in two places. Faster than light travel! Sometimes no clump can be seen. Where'd they go? Poof, out of existence.
You want a quantum simulator? Starlings, go watch a flock of starlings and apply your quantum equations to their motion.
You may think I'm kidding, but the same problem exists. Just as you can't see the individual bird, only the flock, likewise you've built a bunch of equations for a flock of smaller particles. You can only detect the flock and not the particles.
Keeping with your analogy ... In order to exactly determine the location of each single starling, you need a shotgun(s). Then it no longer is part of the flock now that it has been observed.
As an aside, I am aware that you can shoot at a flock of starlings all day and not hit a one.
... if you know the computer's speed, you cannot know where the computer is.