1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Qubits!!

Discussion in 'The Lounge - Off Topic' started by Pedrito, Nov 10, 2005.

  1. Pedrito

    Pedrito Nibble Poster

    50
    2
    10
    I'm not sure if I have chosen the right forum for this thread :unsure

    After doing some research on bits and bytes, and bobs :dry :biggrin I came across Qubits, which - by my understanding - is supposed to replace the bit as the smallest information unit!

    Since I am only at the A+ level, this subject is probably way above my understanding, but since that has never stopped me before I thought I'd delve a bit further into this interesting development.

    I would just like to know what your opinions are on this and at the same time, try to understand what relationship a Qubit would have with a bit and a byte. Like a byte is typically 8 bits, so would a bit become a set number of qubits?

    Please check out this link for more info on a Qubit

    http://en.wikipedia.org/wiki/Qubits
    Also, follow the links provided near the bottom of the page for further reading.
     
    WIP: A+; N+; MCSE
  2. Bluerinse
    Honorary Member

    Bluerinse Exabyte Poster

    8,871
    167
    256
    From what I can see Pedrito this has nothing at all to do with the type of computers we are all interested in i.e. PCs (personal computers) and servers.

    The notion of a bit being 1 or 0 can just as easily be described as a high or a low or an on or an off. You cant get much less than an off or a zero.

    This has to do with the way semi conductors work. A common or garden transistor which has three legs (collector - base - emitter) will pass current from the emitter to the collector depending on the base voltage. It has little to do with binary at this level but it is simply a switch. If the correct voltage is applied to the base it will conduct, if not it wont, hence the on and off state I mentioned before. Integrated circuits are just a collection of transistors. CPUs are just integrated circuits on steroids there are thousands of transistors in one small slab of silicon, all switching on and off in response to the others state.

    So given my brief poor example above, you can see that a bit is sufficient, even when you delve into And gates Or gates, Nor gates etc, they are still only a collection of transistors configured to behave in a certain way depending on the input of a high or a low.

    Bytes are just a chunk of bits, processing a byte at a time is faster than a bit at a time and so on. 64 bit processors work in chunks of 64 bits at a time and are hence faster but the basic principle of on/off still applies.

    What you are linking to is information on quantum computing an area that I have no understanding unfortunately and one that I doubt will affect the general publics computing habits in my lifetime.
     
    Certifications: C&G Electronics - MCSA (W2K) MCSE (W2K)
  3. ffreeloader

    ffreeloader Terabyte Poster

    3,661
    106
    167
    To tell the truth, that page was so far over my head I was lost. If you're smart enough to understand it, you'll go far.
     
    Certifications: MCSE, MCDBA, CCNA, A+
    WIP: LPIC 1
  4. Pedrito

    Pedrito Nibble Poster

    50
    2
    10
    G'day Bluerinse :)

    I'm sorry, but it has been a long time since I've used forums so I apologise for the lack of quotes :oops:

    Thanks for that explanation, and for giving me a better idea on the whole concept of bits and bytes. Your last sentence answered my curiosity the best, because that was pretty much what I was wondering.

    I agree with you ffreeloader :D I've never enjoyed having to work out what does x equals when y is that or a is the other, and just the thought of having to work out that bad boy gave me the hibby jibbies :blink




    Also, Kylie Minogue has my vote for the sexiest women around :wink: that is, ever since Catherine Zeta Jones decided to open her yap hole :dry She crushed the fantasy with just two words: Michael Douglas :sick
     
    WIP: A+; N+; MCSE
  5. arisen

    arisen Byte Poster

    243
    15
    46
    Just read that wikipedia page, pretty interesting stuff. This is my understanding of what a qubit is and what quantum computing is about:

    The thing with quantum physics, as i understand it is this, it's related to measuring the state of something like a particle, a charge on a particle, a particle's momemtum, a sound wave's frequency at any particular time etc.

    For example, the charge on an elementary particle. The Heisenberg uncertainty principle states that when measuring the state of two quantum particles, we cannot definately predict the state of the two particles without first making a mearsurement.

    Say you had two boxes, each with a glove inside, but you can't see inside the boxes. ok, how would you know which box contains the right hand glove, and which the left hand glove?

    Well you wouldn't, until you made a measurement, i.e. open one box. The uncertainty principle says that until you make a mearsurement, the state of a quantum element is uncertain, it will vary constantly in an uncertain state. ie the gloves will in fact not be right or left but at strange and varying degrees between those! :eek:

    Now look at the qubit. It's comparison to a regular bit, which bluerinse described, within a cpu is just the state of a transistor, 1 or 0, on or off. The qubit will have a multitude of various states it can be in. This means it will be able to hold much more information in a single unit of information. This is acheived through quantum superposition, which means that different states can be superimposed on a single qubit. Like when you add amplitudes of waves together, superimposing them on one another, you get a result. This will be an observable state, but you could still measure the individual states that went into the final state. This means a string of binary values (spin states of particles for example) 10001 or 11101 could be present in a single qubit.

    This also means a qubit register could perform a binary calculation INDEPENDENTLY from all the other qubit registers in the system. So it's like parallelism going on too, you have calculations being done in parallel at each qubit register. This is in contrast to a binary computing system, which can only perform one calculation at a time. So that's why quantum computers are going to be so much more powerful 8)

    Well that's my understanding anyway :blink , and i'm probably wrong too, but i had a shot! :biggrin

    Sorry for the long post/quantum rant :oops:
     
    Certifications: BEng, PRINCE2, ITIL, Net+
    WIP: MSc, Linux+ 2009, RHCE
  6. Pedrito

    Pedrito Nibble Poster

    50
    2
    10
    "The qubit will have a multitude of various states it can be in. This means it will be able to hold much more information in a single unit of information. This is acheived through quantum superposition, which means that different states can be superimposed on a single qubit."

    "This also means a qubit register could perform a binary calculation INDEPENDENTLY from all the other qubit registers in the system. So it's like parallelism going on too, you have calculations being done in parallel at each qubit register. This is in contrast to a binary computing system, which can only perform one calculation at a time. So that's why quantum computers are going to be so much more powerful 8) "

    Arisen, you totally blew my mind with these two :p

    So let me try to understand this. The qubit won't replace a bit as the smallest information unit, but as the most advanced and powerful information unit? And if so, please tell me that I won't have to do any algebra :blink :biggrin

    Would you agree with Bluerinse and say that quantum computers won't be around for many of our lifetimes? (I don't know how old Bluerinse is, but momma always told me its rude to ask :cheeseyg )
     
    WIP: A+; N+; MCSE
  7. arisen

    arisen Byte Poster

    243
    15
    46
    Yeah i guess so, i'm still a bit hazy on it myself :oops: but i think that's the general gist. I found a cool description here

    In essence a qubit is able to represent a binary value of 0 and 1 SIMULTANEOUSLY due to superposition. So if you had a 2-bit register for example, you could only have 4 possible permutations, i.e. 00, 01, 10 and 11 right? Well since a qubit can be both a 1 and a 0 simultaneously, a 2-qubit register would hold all four permutations AT THE SAME TIME! :eek:

    Cooool! 8) But definatley no algebra! :p

    Apparently certain groups such as IBM have already managed to build working quantum computers, like this 5 qubit machine. So you never know, maybe we'll have quantum computers calculating our pension payments some day :biggrin
     
    Certifications: BEng, PRINCE2, ITIL, Net+
    WIP: MSc, Linux+ 2009, RHCE
  8. simongrahamuk
    Honorary Member

    simongrahamuk Hmmmmmmm?

    6,199
    125
    199
    :eek: Help! :eek:
     
  9. nugget
    Honorary Member

    nugget Junior toady

    7,796
    71
    224
    Arisen, you really summed it up brilliantly. :thumbleft

    Imagine the throughput of information possible.
     
    Certifications: A+ | Network+ | Security+ | MCP (270,271,272,290,620) | MCDST | MCTS:Vista
    WIP: MCSA, 70-622,680,685
  10. Bluerinse
    Honorary Member

    Bluerinse Exabyte Poster

    8,871
    167
    256
    I am 50 so I was playing safe :twisted:
     
    Certifications: C&G Electronics - MCSA (W2K) MCSE (W2K)
  11. Pedrito

    Pedrito Nibble Poster

    50
    2
    10
    Thanks for all the info on Qubits everyone. Truly mind blowing stuff :microwave

    Nevertheless I must show my ignorance once more and clarify something :oops:

    So are these processors already 'prepared' to respond to any possible permutation? In other words, they have all of the possible outcomes already memorised within them?





    :oops: :biggrin

    I am always jealeous of anyone around 60 years old for one main reason: they were my age during the 60s and 70s. Imagine what it must have been like during those years. Sex, drugs, the best music to date.

    Ah... the days when a young Bob Dylan was shocking fans by going electric; Jimmy Hendrix shocking dentists by playing guitar with his teeth; and the Beatles on their way to shocking the world by proclaming they were bigger than Jesus. Yes good times. Apparently, so I'm told, you could also buy a normal 3 bed semi for just £3000, and a brand new average run-of-the-mill car for £20 :shocked

    Still... I prefer living with the unpredictability of what lies ahead.
     
    WIP: A+; N+; MCSE
  12. Phoenix
    Honorary Member

    Phoenix 53656e696f7220 4d6f64

    5,726
    175
    221
    Quantum computing may not be as far off as people imagine, the theory and technology has been in the works for years, even decades, in fact the fruitation of the research is already coming to bear, with end to end quantum encryption already possible (not based fully on quantum computing mechanisms, but a subset of said research into quantum mechanics) I believe we will see these technological benefits in our lifetime, hwo they will impact our already over complex lives I dont know.

    Thier first major inroads will obviously be military and RnD, medical research, protein sequencing, nuclear blast simulating, weather mapping/predictions, and other such process intensive tasks, the parellism of such processes will enjoy the benefits of quantum computers almost immediatly, and may well negate the need for complex grid systems currently employed in these tasks

    The futures bright,
     
    Certifications: MCSE, MCITP, VCP
    WIP: > 0
  13. moominboy

    moominboy Gigabyte Poster

    it is pretty exciting talking about all this quantum computing but i daresay it'll be a while before us normal folks see any kind of impact in our lives.

    scary stuff too if you think about it.....terminator anyone?! :twisted: :twisted:
     
    Certifications: ECDL
    WIP: A+
  14. ffreeloader

    ffreeloader Terabyte Poster

    3,661
    106
    167
    In my opinion, Pedrito, you're missing the best part of the 60's and 70's. The people. The common man was much different then. I don't remember us ever locking our doors unless we were going to be gone for a day or so. I also remember people being kinder, far more polite, and just over-all friendlier. Yes, humans were still flawed back then, but the flaws were somehow different. There was little of the out-and-out greed that we see today and the willingness to stomp on your fellow man's head to get above him was far less common than it is today. Today it seems to be the norm, then it was the exception. At least where I lived that's the way people were.

    It's a totally different world today than it was 40 years ago. To me it's almost as different as night and day and factors you listed seem almost inconsequential to me. It's the fundamental changes to society that I see as the negatives for today. The music today is just a symptom of the changes in attitude.
     
    Certifications: MCSE, MCDBA, CCNA, A+
    WIP: LPIC 1
  15. Pedrito

    Pedrito Nibble Poster

    50
    2
    10
    Hi ffreeloader,

    Firstly, I admire what you have just said, and I can only apologise if, in any way, I disrespected those times that you seem to hold dear :oops: That was never my intention. You must understand that due to my age and experience that is what I can value the best at this moment in time.

    This is not to say, however, that I can't relate to what you said. I grew up in a small village until I moved to the UK when I was 13, and the spirit of that close community still remains with me to this day. I know what you mean about the changing attitudes, and I consider myself fortunate that I have had a good upbringing that instilled in me some fundamental moral values.

    But it is incredibly difficult to keep going back to these values. The whole world seems to be in a state of constant uncertainty, kinda like quantum computing :biggrin and few are really sure about what is truly important.

    I guess the 60s and 70s were about realising that life and peace are precious gifts, but it took several war-stricken years to make people join together in these common ideals.

    Today, these ideals aren't really the priorities in people's minds, because as Phoenix said our lives are complex enough without having to worry about irrelevant stuff in regards to today's world.

    Most of what you said is also a popular view with some of my friends who are in their 50s-60s. Needless to say, I always end up asking them to tell me about the music, and the girls. One of them once told me that they were like 'dolls'. He remembered that they didn't used to care so much for make-up, and so a man could see her real beauty because it wasn't being hidden behind a 'mask' or incredibly revealing clothes. Right on brother 8)

    But, come on :) I bet you had some good times in those days!
     
    WIP: A+; N+; MCSE
  16. Jakamoko
    Honorary Member

    Jakamoko On the move again ...

    9,915
    60
    229
    Just to drift back on-topic, this is one truly compelling thread, as I have always had more than a passing fondness for quantum theory (doesn't mean I can full get my head round it tho)

    This point stands out for me tho:

    Firstly, let me say I probably have not fully armed myself with the facts here, as I havent fully scanned the wiki posted initially, but aren't you defeating your own argument here, arisen ? To clarify, if a circuit can have 2 conceivable states, aka 1 and 0, then by Heisenberg's Uncertainty Principle and and also Schroedingers Cat theories, then it is in both states simultaneously until measured quantifiably. Therefore it cannot be in a muliplicity of states, as it can only exist in two. Sorry in advance if I have mis-construed you, of course.

    EDIT: Having now read the wiki and followed one of the links, THIS LINK back's up my thoughts above.



    Which brings to me to my favourite quantum physics gag (there's more than one ?!?!??)

    Heisenberg takes a job running the local High School. One day, a young mis-creant pupil is sent by his teacher to face the wrath of Heisenberg. Nervously, he knocks on the office door, and upon being summoned timidly enters.

    "Excuse me," murmurs the young urchin, "are you the Principle ?"

    "Well, you see, maybe ....." replies Heisenberg ! :biggrin
     
    Certifications: MCP, A+, Network+
    WIP: Clarity
  17. arisen

    arisen Byte Poster

    243
    15
    46
    Hey Jaka, nice post! :thumbleft

    Well to tell you the truth, i can't really remember exactly what i was getting at when i wrote that particular line of that post! So you may well be right! I'll have to do some more reading and get my own concepts straight! But the following occured to me after reading your post:

    1) I guess what i was trying to say (poorly) was that a qubit's measurable state could either be a 0 or 1, or all states in-between. Check this out:

    [​IMG]

    This seemed to lead on from the equations on the qubit wiki :

    [​IMG]

    Would you say by looking at the above equations, that a qubit state can in fact range from ket0 to ket1 and states therebetween? That's kind of what i was trying to say! States within states if you will :oops: Please go ahead and shoot me down if my interpretation of the maths is wack! :biggrin

    2) By referencing schrodingers cat paradox i'm assuming you prefer the many-worlds interpretation over the plain copenhagen one?! :biggrin Yes i agree with you, due to entanglement and decoherance when an observation is made, quantum superpositioning does not persist and a qubit state of superposition will therefore 'choose' a 0 or a 1. But how does the link you referenced as backing up your thoughts disprove that a qubit can in fact be in a multiplicity of states BEFORE decoherance takes place? (Assuming the above mathematical assumptions haven't already done that!)

    Woah, i'm getting lost in my own mind here... :eek: I think i need to read some more! :dunce
     
    Certifications: BEng, PRINCE2, ITIL, Net+
    WIP: MSc, Linux+ 2009, RHCE
  18. Jakamoko
    Honorary Member

    Jakamoko On the move again ...

    9,915
    60
    229
    It can only be in as many states as it is possible for that entity to be in. Schrodingers Cat can only (and simultaneously) be dead and/or alive. In other words, it has two potential states at any given time, so can not be in a multiplicity of states.

    The theory of Decoherence implicitly states that the very theory to which it relates automatically ceases to exist as soon as it is applied and is therefore questionable from the outset.

    Whilst we sit back and draw deep, I'm sure that you and I (and any remaining readers) will agree that we have stumbled upon the classic Saturday night quantum physics discussion, that which I strongly suspect (but again, without certainty) was probably how the entire theory came about in the first place !!! :biggrin
     
    Certifications: MCP, A+, Network+
    WIP: Clarity
  19. Pedrito

    Pedrito Nibble Poster

    50
    2
    10
    Yeah, sorry about that! :oops: I tend to get carried away sometimes, and the 60s and 70s did seem to be a great time to experience. ffreeloader, thanks again for your post 8)

    But since this topic is attracting some attention I thought I'd delve further and attempt to illustrate it in my own (probably very off-target) way. Please change accordingly...

    So, a byte, made up of 8 bits, looks like thus:

    128s 64s 32s 16s 8s 4s 2s Units
    1 1 1 1 1 1 1 1 (this represents the maximum value that can be held within a byte, minimum would be all the 1s being 0s, right?)

    A qubit (this is based on the 5 qubit computer Arisen referred to) would look something like:

    1 2 3 4 5
    /\ /\ /\ /\ /\
    0-1 0-1 0-1 0-1 0-1
    \/ \/ \/ \/ \/

    in that 1 qubit consists of ket0 and ket1 interchanging with each other in numerous states? Am I anywhere close?

    EDIT: apparently my illustration doesn't show up very well on the post. It definitely went wrong somewhere :oops: Just imagine that first qubit is the norm, and the others look exactly the same i.e.

    1
    /\
    0-1
    \/
     
    WIP: A+; N+; MCSE
  20. arisen

    arisen Byte Poster

    243
    15
    46
    But isn't there a big difference between an elementary ion and a macroscopic moggie :biggrin . The theories of quantum mechanics do not generally apply to macroscopic entities (excluding superconductors [qubits] and superfluids). Thus the theories of relativity do not apply to a car driving along a motorway, but do apply to entities travelling close to the speed of light. Maybe classical analysis should not be imposed on quantum phenomena, but rather used to provide a more complete model of quantum mechanics under differing conditions? :D Schrodingers cat thought experiment was not intended to disprove quantum superpositioning but instead to indicate that the theory was incomplete.

    I would say that it does implicitly say that wavefunction collapse occurs, and therefore goes a long way to confirming the existence of superposition before the fact. You have to have something there in the first place to collapse! If superposition does not exsist, then how to quantum computers offer the promise of increased computational power? Where do they get it from? The link you quoted says it all, decoherence can be delayed for enough time to be able to use superpositioning for increased computational performance.

    Pedrito > Yes i think you're pretty much right, but how superpositioning is actually made to be useful, that's another story! :biggrin. Maybe the benefits are only in parallel computation through independent qubit registers????
     
    Certifications: BEng, PRINCE2, ITIL, Net+
    WIP: MSc, Linux+ 2009, RHCE

Share This Page

Loading...