The big one is they think that a quantum computer would just magically revolutionize everything -- machine learning, optimization, you name it -- and that it would do so by simply "trying all the possible answers in parallel."
They don't get that quantum speedup is an incredibly special phenomenon that hinges on the way quantum mechanics changes the rules of probability themselves, to allow complex numbers called "amplitudes" that can interfere and cancel each other out (unlike probabilities, which can only add).
And, as a conseqeunce of the nature of quantum speedup, we know of world-changing quantum speedups mostly just for two specific classes of problems, which have the exact right structure to take advantage of interference among amplitudes: (1) simulating quantum mechanics itself (the "O.G." application from the 1980s), and (2) breaking the main public-key cryptographic codes that are used to protect the Internet (that was Peter Shor's famous discovery of 1994).
Since this is weird and confusing and takes at least 15 minutes to explain properly, and ALSO is not really what customers or investors want to hear, a very common solution that people hit on is simply to lie about it! :-D
The big one is they think that a quantum computer would just magically revolutionize everything -- machine learning, optimization, you name it -- and that it would do so by simply "trying all the possible answers in parallel."
They don't get that quantum speedup is an incredibly special phenomenon that hinges on the way quantum mechanics changes the rules of probability themselves, to allow complex numbers called "amplitudes" that can interfere and cancel each other out (unlike probabilities, which can only add).
And, as a conseqeunce of the nature of quantum speedup, we know of world-changing quantum speedups mostly just for two specific classes of problems, which have the exact right structure to take advantage of interference among amplitudes:
(1) simulating quantum mechanics itself (the "O.G." application from the 1980s), and
(2) breaking the main public-key cryptographic codes that are used to protect the Internet (that was Peter Shor's famous discovery of 1994).
Since this is weird and confusing and takes at least 15 minutes to explain properly, and ALSO is not really what customers or investors want to hear, a very common solution that people hit on is simply to lie about it! :-D