What The Heck Is Quantum Computing?

[coljohnhannibalsmith]

Hello,

The same NetFlix program on hacking, that I referenced in my earlier thread, discussed the use of quantum computing by governments for the purpose of cracking public key encryption for digital eavesdropping. The fact that the current Von-Neumann computational process is sequential, rather that parallel, was cited as its primary limitation, especially when it comes to factoring large semi-prime numbers, the process needed to crack public-key encryption. Today's large supercomputers like NASA's Pleiades and the Blue Waters supercomputers address this problem by daisy-chaining several hundred thousand sequential 64bit processors together. According to the NetFlix program, quantum computing uses a property of the quantum world that allows a particle to be in several places at once ( I suspect a very incomplete first approximation) to allow a quantum computer to try all the different combinations at once. Perhaps particles at the quantum level simply move so fast in their orbits that they only "appear" to be everywhere at once, at least using light as the radiation with which the phenomenon is being observed, which has finite properties. I also suspect that quantum-entanglement would have to play a role to get all the Q-bits to work together.

I've pretty much gotten most of my understanding of quantum-entanglement from blogs and television rather than experimentation; but my understanding is that photons are exchanged between electrons which causes their spins to remain linked in the opposite directions until the entanglement is broken. This implies an FTL communication link between them by some unknown form of radiation, in this universe, or information being passed between them through some sort of sub-universe, where time exists, but distance does not. I suppose one could visualize this as the motherboard or backplane of our three dimensional universe, which apparently needs lots of additional processing, which we can't normally see, to exist.

Philosophy aside, I'd really like to know how this works in a practical sense. It seems a company in Canada called D:Wave has already built one. Here's the article:

http://www.canadianbusiness.com/technology-news/quantum-computing-how-canada-is-going-to-change-the-world/

I wonder which OS they're using? I'd also like to know who their customers are and what they're using them for. Oh, to be a fly on the wall of D:Wave accounts receivable!

Hannibal

[QIII]

If anyone in the world has moved on from a few very small experiments using a very small number of quantum bits to having a fully functional quantum computer, I am sure that every University in the world would be very interested to know.

Quantum computing is at best in its infancy.

[coljohnhannibalsmith]

Oh, here's a way cool video from the company's website.

http://www.dwavesys.com/

BTW, I did recommend they upgrade their OS to Ubuntu:D

[jamesdesbyrne]

Just to tap them off super quick.

- There are currently no quantum computers which can be used for cracking security in that way, they are still very much so experimental
- An electron or other quantum element does move through every possible permutation of its movement simultaneously. This was proven earlier this year. Its not a matter of speed rather another counter-intuitive aspect of quantum mechanics called superposition : https://en.wikipedia.org/wiki/Quantum_superposition#Quantum_mechanics_in_imagina ry_time

- The nature of quantum entanglement is still up for debate, whether the two particles can communicate faster than light or they are born with hidden information is still unclear
- Quantum entanglement cannot be used for storing or sending information because although the spins are always opposite they are also random
- A quantum computer cant function as a normal computer and would likely be a terrible replacement for our computers

You can find a really good video on quantum computing by Veritasium (https://www.youtube.com/channel/UCHnyfMqiRRG1u-2MsSQLbXA) here :

https://www.youtube.com/watch?v=g_IaVepNDT4

He also does a good one on quantum entanglement

[grahammechanical]

You would not know a quantum computer was running until it gave the answer to the question.

[QIII]

Despite what the company may claim, they do not have a working quantum computer. They have what may be something that operates on a very finite number of qubits and surrounds that with a pretty standard conventional computer. In fact, its "computing power" is something on the order of 1/1000th of the speed of a conventional computer. I say again: It is slower than your desktop.

NASA does not use theirs for answering the mysteries of the Universe, but for experimenting with quantum computers on a very finite scale and proving concepts for algorithms that might be useful. They aren't "doing" anything with it in any meaningful way.

The company is FAR overstating what they have -- to the point of scientific and commercial fraud if they are actually trying to sell it as such.

[coljohnhannibalsmith]

- The nature of quantum entanglement is still up for debate, whether the two particles can communicate faster than light or they are born with hidden information is still unclear.

Hidden information, would that be like metadata?

[monkeybrain20122]

You may want to play with this http://qcplayground.withgoogle.com/#/home

:)

[coljohnhannibalsmith]

Just to tap them off super quick.

- There are currently no quantum computers which can be used for cracking security in that way, they are still very much so experimental
- An electron or other quantum element does move through every possible permutation of its movement simultaneously. This was proven earlier this year. Its not a matter of speed rather another counter-intuitive aspect of quantum mechanics called superposition : https://en.wikipedia.org/wiki/Quantum_superposition#Quantum_mechanics_in_imagina ry_time

- The nature of quantum entanglement is still up for debate, whether the two particles can communicate faster than light or they are born with hidden information is still unclear
- Quantum entanglement cannot be used for storing or sending information because although the spins are always opposite they are also random
- A quantum computer cant function as a normal computer and would likely be a terrible replacement for our computers

You can find a really good video on quantum computing by Veritasium (https://www.youtube.com/channel/UCHnyfMqiRRG1u-2MsSQLbXA) here :

https://www.youtube.com/watch?v=g_IaVepNDT4

He also does a good one on quantum entanglement

Thank you tremendously. I was able to follow the written material, with the exception of the math; and the videos were on target and clarified many things for me. I had Calculus in college and was wondering what you think I might need to learn to actually follow the math?

Hannibal

[yoshii]

I read some articles every few months about this stuff. Some experts still think Quantum Computing isn't yet a reality at all and that it's just shrouded in mystery, controversy, and hype. But Scientific American has written about it as well as New Scientist if you want to read more on the topic.

[coldraven]

My understanding of the present quantum computing situation is that they can only try to solve algorithms they they already know the answer to. Presumably so that they can check if it's working properly. On a deeper level for a long time it has been believed that answers to questions are already "out there" and what is needed is the ability to ask the question. For example, sometimes an invention or concept is developed simultaneously in different parts of the world by people with no connection.
So with that in mind you might like to consider the old art of fortune telling as a form of quantum computing. When a shaman tosses some bones in the air do they now exist in a quantum state? Maybe the act of asking the question determines the pattern of the bones when they fall. So get three identical coins and a copy of the I Ching and you are in the quantum computing business :)
https://en.wikipedia.org/wiki/List_of_hexagrams_of_the_I_Ching

[coljohnhannibalsmith]

My understanding of the present quantum computing situation is that they can only try to solve algorithms they they already know the answer to. Presumably so that they can check if it's working properly. On a deeper level for a long time it has been believed that answers to questions are already "out there" and what is needed is the ability to ask the question. For example, sometimes an invention or concept is developed simultaneously in different parts of the world by people with no connection.
So with that in mind you might like to consider the old art of fortune telling as a form of quantum computing. When a shaman tosses some bones in the air do they now exist in a quantum state? Maybe the act of asking the question determines the pattern of the bones when they fall. So get three identical coins and a copy of the I Ching and you are in the quantum computing business :)
https://en.wikipedia.org/wiki/List_of_hexagrams_of_the_I_Ching

Perhaps I can use my browser as a plugin to the Universal Help Desk, where I'm sure there are plenty of minimum-wage angels providing the answers, with Medatron as the cruel call-center overlord. Yes, I'm familiar with the concept of a species specific collective-unconcious aka 100 monkey rule. Frankly, I really don't buy it; and I suspect the experiments with mice weren't conducted properly or the results exaggerated or both. I think having the answers already out there would be a panacea for the lazy or those who obtain their good ideas primarily through visual theft. Imagine, a universal end to rtfm-ing; 'tis a consummation devoutly to be wished. I'm really not a fan of the Copenhagen Interpretation of the double-slit experiment either. I suspect that the natural state of an electron or other quantum object is rather a sort of smear; and that the act of observation, for instance with a tunneling electron microscope, affects the results. Here's a simple analogy. Suppose you want to read the temperature of a dark room; so you hold a flashlight to the thermometer. The additional infrared energy transmitted to the thermometer raises the temperature slightly, so the reading becomes an inaccurate representation of the true ambient temperature of the room. At the macroscopic level, this effect is miniscule; but at the extreme microscopic level of the quantum world, this effect becomes extremely significant. At this level, I would argue, that there is no such thing as passive observation. All observation adds energy to the natural phenomenon being observed; and this extra energy pollutes that phenomenon.

Hannibal

[coldraven]

Imagine, a universal end to rtfm-ing; 'tis a consummation devoutly to be wished :lolflag:

I have come to the conclusion that our universe is a simulation. To avoid breaking the forum rules I shall use the example of advanced aliens. Some years ago in the New Scientist magazine an article postulated that a civilization a million years ahead of us would have computers powerful enough to create virtual realities. So if they wished to experience an historical era they could just run a simulation and step inside it.
If there was a civilisation even older, say a billion years, they might well have no need for physical machines as we know it. If one of these wanted to create life-forms he/she would be daft to do it in their own reality, if the life-forms turn out to be bad they could destroy the "world" of their maker. So the alien creates a virtual reality, drops the life-forms in, occasionally tweaks the settings and possibly makes personal appearances to give hints to the natives.
After some time the simulation would come to an end, the life-forms that turned out to be good would be allowed to enter the real world. The rest just get deleted. An analogy would be that rather than being a character in a book you would have the chance to actually be in the library.
Back to quantum weirdness, in a thought-form simulated universe "place" means "state", maybe that explains entanglement.
I'm just off to teleport myself to Sirius, be back tomorrow :)

[coljohnhannibalsmith]

:lolflag:

I have come to the conclusion that our universe is a simulation. After some time the simulation would come to an end, the life-forms that turned out to be good would be allowed to enter the real world. The rest just get deleted. An analogy would be that rather than being a character in a book you would have the chance to actually be in the library.

Back to quantum weirdness, in a thought-form simulated universe "place" means "state", maybe that explains entanglement.
I'm just off to teleport myself to Sirius, be back tomorrow :)

I have come to the conclusion that the forum is a simulation where our bad ideas get weeded out; so we are more likely to enter a quantum state of grace:D If the rest just get deleted, humanity is in serious trouble;) For the moment, I suspect that entanglement would be easier to understand if we abandon the notion that the behavior of quantum objects is random. Like everything else in nature, they must respond to their environment. Perhaps at the moment of entanglement a script is written to both, so that no communication between the objects is necessary; and the entanglement is only broken when one or both of these objects get reprogrammed? Perhaps we could program a string of gluons to perform simple sub-routines. Now that would be a cool way to write an OS! All Hail Bashful Bandicoot 31.10.04:lolflag: Please see attachment.

[francescopasa]

Basically a quantum computer is nothing like a traditional computer. It operates in a completely different manner and cannot substitute normal computers. The concept is somewhat interesting tough, because there are some algorithms that have been proved to run faster on a quantum computer. Most of these are algorithm that treat problems with cryptography and prime numbers. Some security algorithms are based on prime numbers, so using a quantum computer it might be possible to break current ciphration schemes (not all of course!).

I am not expert in the field, but as a physics student, I can tell you that in Quantum mechanics nothing really has a position and a velocity, rather there are possible positions and velocities. But for the sake of explaining a Quantum computer spin is a better example. An electron can have a spin up or down if you measure it, but it is possible to put this electron into a state in which you do not know which spin it has. If you measure it you will either get up or down with 50% probability each. A quantum computer exploit similar quantum effects, storing and processing information in a similar unknown state. However the field is extremely experimental at best.

If quantum computing will ever work, it will find niche applications.

[coljohnhannibalsmith]

Basically a quantum computer is nothing like a traditional computer. It operates in a completely different manner and cannot substitute normal computers. The concept is somewhat interesting though, because there are some algorithms that have been proven to run faster on a quantum computer. Most of these are algorithms that treat problems with cryptography and prime numbers. Some security algorithms are based on prime numbers, so by using a quantum computer it might be possible to break current ciphration schemes (not all of course!).

If quantum computing will ever work, it will find niche applications.

Back in the day, many PCs had math coprocessors. I suspect we will eventually see Quantum coprocessors; not entire quantum computers.

[Skaperen]

i'll know they are real when i see them on sale at Wally-World.