Best quote from the paper:

"Will anybody be capable of riding this 
machine? 

Thus, the answer to the question in title is: As soon as the physicists and the engineers 
will learn to control this number of degrees of freedom, which means - NEVER."

janetyellen

There's a more general public-friendly and newer paper by the same guy here: 

https://ebooks.iospress.nl/pdf/doi/10.3233/APC200019

I'm going to send this out along with the classic Locklin article whenever anyone asks me about quantum computing and Bitcoin from now on.

bitcoin

Quantum Computing Paper - PROSPECTS FOR QUANTUM COMPUTING: EXTREMELY DOUBTFUL

jimmysong

There's a more general public-friendly and newer paper by the same guy here: https://ebooks.iospress.nl/pdf/doi/10.3233/APC200019

I'm going to send this out along with the classic Locklin article whenever anyone asks me about quantum computing and Bitcoin from now on.