Ramsey numbers, quantum computing, hype
World’s Largest Quantum Computation Uses 84 Qubits:
http://www.technologyreview.com/blog/arxiv/27483/?p1=blogs
That’s cool, but the article totally misleads the readers as to what actually was computed.
Bian and co say the calculation for R(8,2) used 84 qubits, of which 28 were used in the computation and the rest for error correction. It took just 270 milliseconds. The result is 8 (as has been known for many years by conventional methods).
The result is 8 (as has been known for many years by conventional methods).
It’s like saying “2×2=4 has been known for many years by conventional methods”. R(n,2) = n is in fact more trivial than 2×2=4. It basically means that if you take n points and connect some of them, then either all of them are disjoint or at least 2 of them are connected, duh.
See here http://www.cut-the-knot.org/Curriculum/Combinatorics/ThreeOrThree.shtml for a nice popular explanation of Ramsey numbers.
Also, somewhat related combinatorial problems that I wrote about: Crocodile dinner, Crossing lines
