That's incorrect, the number of combinations for N destinations is N!, not 2^N. So for 6 destinations there are 720 combinations and for 20 there are 2.43290201 × 10^18.
http://en.wikipedia.org/wiki/Permutation#Counting_sequences_...
https://en.wikipedia.org/wiki/Travelling_salesman_problem#Ex...
lol, i used to work at LM advanced research, LM consistently blows 10 mil over 3 ears on stupid dead end projects and nobody even blinks. This is not a criticism of LM so much as it gives us insight into the size of budget and scope of projects the work with. they did 45bn revenue in 2011 per wikipedia. this d-wave project looks like a toy that some kids in a lab bought.
but it doesn't matter how it looks to us. quantum computing is a weapon, and as such is highly classified. i'm not sure we can draw any conclusions at all about the state of quantum computing from information in the public domain and if LM had a larger relationship with d-wave or similar companies, we wouldn't know.
Just a comment given in unofficial conversation, take it how you will.
Most interesting to me: "Geordie presented graphs that showed D-Wave’s quantum annealer solving its Ising spin problem “faster” than classical simulated annealing and tabu search (where “faster” means ignoring the time for cooling the annealer down, which seemed fair to me). Unfortunately, the data didn’t go up to large input sizes, while the data that did go up to large input sizes only compared against complete classical algorithms rather than heuristic ones. (Of course, all this is leaving aside the large blowups that would likely be incurred in practice, from reducing practical optimization problems to D-Wave’s fixed Ising spin problem.) In summary, while the observed speedup is certainly interesting, it remains unclear exactly what to make of it, and especially, whether or not quantum coherence is playing a role."
So, D-Wave may be selling an expensive simulated annealing hardware implementation, rather than a quantum computer.
1. Qubits can be 1 and 0 at the same time
2. ...
3. Solve hard problems!
Can someone provide a link that fills in the middle somewhat? Preferably, aimed at an audience with something closer to undergrad engineering degree and than a PhD?
I think it less about it being outrageous and more about the fact that he and the company's press releases sound more like infomercials then technological descriptions. Which historically seems to happen with pseudoscience based companies.
Oh? I thought he only proved that it's impossible for an algorithm to determine whether an arbitrary program will halt -- not whether all errors can be eliminated from software.
No, wait, it's over there!
One thing is for sure - we're uncertain where quantum computing is right now.
(yes, bad joke. It seems to work on a couple of different levels, though)
(even worse follow-up on a bad quantum joke)
