- 12 Jun '13 11:33 / 3 editsPhysicists show self-correcting quantum computers are theoretically possible:

http://phys.org/news/2013-06-physicists-self-correcting-quantum-theoretically.html

I find that article quite informative. I have leaned something new here; didn't know about there being three types of quantum computer.

The only bit that looses me is where it says;

“...Color codes are a class of topological codes, which themselves have gained attention as a new phase of quantum matter due to their topologically ordered states. ...”

-not sure what that means. - 12 Jun '13 14:46

Yeah, I read that article. I think the topological statement means certain shapes, like sticks with balls at the end in certain arrangements, each configuration standing for a certain quantum state. At least that's what I got out of it.*Originally posted by humy***Physicists show self-correcting quantum computers are theoretically possible:**

http://phys.org/news/2013-06-physicists-self-correcting-quantum-theoretically.html

I find that article quite informative. I have leaned something new here; didn't know about there being three types of quantum computer.

The only bit that looses me is where it says;

“...Color ...[text shortened]... e of quantum matter due to their topologically ordered states. ...”

-not sure what that means. - 12 Jun '13 15:37

Yeah, that is what we are. I am just wondering when you are going to ever self-correct to overcome the evil-lution lies of the devil.*Originally posted by humy***Physicists show self-correcting quantum computers are theoretically possible:**

http://phys.org/news/2013-06-physicists-self-correcting-quantum-theoretically.html

I find that article quite informative. I have leaned something new here; didn't know about there being three types of quantum computer.

The only bit that looses me is where it says;

“...Color ...[text shortened]... e of quantum matter due to their topologically ordered states. ...”

-not sure what that means.

The Instructor - 12 Jun '13 16:15 / 1 edit

Your talking total gibberish as usual.*Originally posted by RJHinds***Yeah, that is what we are. I am just wondering when you are going to ever self-correct to overcome the evil-lution lies of the devil.**

The Instructor

What are you doing on this thread?

Do you have an opinion about quantum computers (laugh) ? - 12 Jun '13 18:39

That's a bit subtle, I had a brief look at the paper which was too long and difficult for the time I gave it. What the topological statement seems to mean is that they arrange their qubits on a lattice and the topology of the lattice affects the behaviour. A major problem with their theory is that it seems to need six or seven dimensions to work properly, which is no help for a practical machine. They hope with further work they'll either be able to reduce the number of dimensions required, or prove that it's impossible in our universe.*Originally posted by sonhouse***Yeah, I read that article. I think the topological statement means certain shapes, like sticks with balls at the end in certain arrangements, each configuration standing for a certain quantum state. At least that's what I got out of it.** - 12 Jun '13 22:06

They may be referring to the word dimension in a mathematical way, like freedom of movement robots have 5,6,8 and more freedoms of movement, each one might be called a dimension. If pieces are out of each others way, then they can call it 6 dimension if they want, they don't interfere with each other, which is the advantage of extra dimensions. Like 2D electronics on a planar surface vs 3D structures that stick out like vertically oriented field effect transistors.*Originally posted by DeepThought***That's a bit subtle, I had a brief look at the paper which was too long and difficult for the time I gave it. What the topological statement seems to mean is that they arrange their qubits on a lattice and the topology of the lattice affects the behaviour. A major problem with their theory is that it seems to need six or seven dimensions to work proper ...[text shortened]... e to reduce the number of dimensions required, or prove that it's impossible in our universe.** - 13 Jun '13 13:58 / 2 edits

No, I think they mean real physical dimensions. The paper is totally theoretical, I don't think they think it's implementable. In the last section (later results) they talk about some contending models which seem to require zero temperature, but which work in 3 dimensions, there's this sentence:*Originally posted by sonhouse***They may be referring to the word dimension in a mathematical way, like freedom of movement robots have 5,6,8 and more freedoms of movement, each one might be called a dimension. If pieces are out of each others way, then they can call it 6 dimension if they want, they don't interfere with each other, which is the advantage of extra dimensions. Like 2D elec ...[text shortened]... anar surface vs 3D structures that stick out like vertically oriented field effect transistors.**

"In particular, some of them introduce new topological codes in more physically accessible dimensions like 3D codes possessing some self-correcting properties."

On the other hand they have qubits at lattice points and provided it's only connectivity and not distance that matters then the lattice could be projected into three dimensional space, and implemented as a network. The number of qubits goes up exponentially with lattice dimension so that could be the accessibilty problem they're referring to.

The problem is that it's a research paper written for a peer group and assumes a common language which the peer group are all used to, but not being in the field we aren't. - 14 Jun '13 14:40 / 2 edits

I only have problems with two parts of that theory: 1) building a massive vacuum. How do you 'build' a vacuum? I work with vacuum systems for a living, just finished 3 vacuum related jobs today, where we get down to 5 E-8 torr level vacuum. You make vacuum by pumping out the bad stuff. The problem is you can't seal a box so well you don't have to run the vacuum pumps, take a look at the vacuum chamber at Cern, the big collider there, 27 km circle. Thousands of cryopumps to just keep the vacuum at a good enough level, WAY better than what I use in the industrial world, like 1E-12 vacuum or better. So those pumps have to keep going just to keep the vacuum at the level they need. So huge pumps, each one drawing say 5 Kw of energy times 1000 and you are already up to 5 MEGAWATTS running 24/7 just to keep that vacuum you have. So this dark matter thingy collecting energy would have to produce many megawatts to achieve breakeven just like what they are going after in the ITER fusion project.*Originally posted by bikingviking***pure speculation: what about building a massive vaccum? then we could get all the energy the world will ever need by harvesting dark matter particles.**

The only way to get that 'massive' vacuum is to drive to space where you get way better than any vacuum achievable in the labs on Earth. So you fly out to space, say ten million miles or so and you get automatic vacuum.

And 2) Just how do you propose to 'harvest' the energy from dark matter?

It has this pesky problem of not reacting much at all with regular matter so extracting energy from it would be near impossible.

Other than those two problems, maybe the scheme has merit......

Don't stop thinking when presented with problems though.