Kitz Forum
Chat => Chit Chat => Topic started by: Black Sheep on July 29, 2022, 04:50:13 PM
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Having a beer with a mate of mine today, and he started going on about quantum computers ........
Have spent an hour on Google 'researching' and you know what, here's the white flag, I surrender. I give up. I yield.
Back to beer and women ;) ;D
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I have a degree in Theoretical Physics and I’m with you, prepared to give up and go back to Netflix and a nice cup of coffee. ;)
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I have a degree in Theoretical Physics and I’m with you, prepared to give up and go back to Netflix and a nice cup of coffee. ;)
:lol: :lol: :lol:
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I defer to the eminent physicist Richard Feynman: 'I think I can safely say that nobody understands quantum mechanics.'
As true today as it was when he wrote it in 1995.
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I defer to the eminent physicist Richard Feynman: 'I think I can safely say that nobody understands quantum mechanics.'
As true today as it was when he wrote it in 1995.
Ha ha - I'm glad it's not just me, then ;D
Just need Kits & B*Cat to join the gang and I'll be one happy sheep. :lol:
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Christopher Barnatt of "ExplainingComputers" did an update on Quartum Computing last Sunday on his regular weekly post:
https://www.youtube.com/watch?v=SORSZ9Je-8g
Probably as near to layman's terms as possible on this complex subject but still way over my head :no:
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Just need Kits & B*Cat to join the gang and I'll be one happy sheep. :lol:
I have to admit to a couple of science degrees but just thinking about a caesium atomic clock gives me a head-ache. ??? :angel:
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Wey hey - nearly a full house !! Watch Kitz rock up, saying she fully understands QC ;D :lol:
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It's pretty simple really. I don't understand what the problem is. ::)
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It's pretty simple really. I don't understand what the problem is. ::)
Ha ha - you know, now you say it .... :lol:
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It's pretty simple really. I don't understand what the problem is. ::)
This gets my vote for best answer. :D
I find the topic quite fascinating, but I can't get my head around it. Over the years I've watched some what appear to be interesting, but feel a failure because at some point my brain will either explode or refuse to store the data. I remember watching a two part lecture that was on BBC iplayer. It was presented by one of what I'd call celebrity scientists... it may have been linked to the Royal Institution, but I cant recall now as it must have been more than 10 years ago. At first I thought I understood and was following it... but at some point in part 2 I found myself rewinding and replaying. These days I doubt I could even watch 10 mins before getting lost. MS and similar neuro diseases scramble your brain making it nigh on impossible to begin computing quantum theories. :/
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Totally appreciate the honesty in all your replies ... if your combined brain power find it a struggle of sorts, then us mere mortals will never get it :) :) :)
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I don’t know whether you think that it’s possible to understand quantum computing at some level without understanding quantum mechanics first, the theory of everything that quantum computing is based on. If one thinks that it’s not possible to understand QC properly without a decent understanding of QM then that means big trouble.
There are several problems with QM that makes it difficult to get your head round it. The first is the philosophy behind QM. QM was developed in a flurry of activity in the mid-to-late 1920s, a time of incredible results achieved at bewildering pace. But even a hundred years later philosophers and physicists concerned with the philosophy of QM are still struggling.
The second problem with QM is that it is highly mathematical (https://en.wikipedia.org/wiki/Hilbert_space); The Hungarian physicist John von Neumann made the definitive mathematical description of QM (QM for mathematicians, if you like) and this features some scary aspects: infinite-dimensional vectors (i.e. arrays, ordered lists or tuples) and each element in the vector (‘list’) is a complex number (https://en.wikipedia.org/wiki/Complex_number). Dealing with infinite-length lists / tuples / infinite-dimensional vectors is horrible, and although physicists and electronics engineers may deal with complex numbers as part of some equation that will ultimately give you real-valued answers (ie ordinary numbers), they are not used to dealing with physical quantities that are end results and are complex-valued. This is because complex numbers make no sense when used for physical quantities. In QM, complex numbers can’t be avoided, in fact their presence is a basic controlling aspect of the theory.
Thirdly, to proceed to more advanced QM it is necessary to have a full understanding of special relativity. Without this, it’s not possible to get to a description of elementary particles. This brings in a load more physics as a pre-requisite.
There are a number of other problematic topics that I could list that come in when dealing with later developments in QM, but these are beyond that which is needed for a firm foundation in QM.
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See - I got to the start of your 3rd paragraph, and it all went Pete Tong for me.
Think I'll stick to football, boxing and beer. ;) ;D
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Can "Schrödinger’s cat" help, a beer in hand does help when reading :)
https://www.newscientist.com/definition/schrodingers-cat/
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It’s not certain that you need to understand QM properly to have a working ‘understanding’, albeit superficial, of QC. It’s you who have to decide.
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The little I read I ran into the issue of "what is it useful for?", as they constantly mention how its not the same as conventional computing so cannot be used for the same workloads.
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Quantum computers are not ‘Turing machines’, a term which we will (mis)use to mean very, very approximately ‘ordinary computers’, for our purposes here, and because of this dissimilarity, it may well be that the set of problems that quantum computers can handle is different from that which all ordinary computers can. Thanks to Alan Turing, Alonzo Church, and others, I forget, it has been proved that all normal computer architectures are as capable as each other when ‘capability’ is defined by the set of problems that these machines can solve given that the problems are chosen such that there are no limits on RAM. Different computer architectures may be faster or slower though, and different models may of course run out of RAM or total disk space allocated for virtual memory, which makes for another practical difference.
However, since imho QCs do not conform to the definition of a Turing machine, they may be able to solve new problems. So this is the source of much of the fuss about QC. Overwhelming speed advantages on certain QC-friendly problems is also extremely important.
(I’m using the term Turing machine not in the original, very earliest sense of Turing’s one particular theoretical design of an extremely simple machine, whose mathematics Turing studied. He did not build this machine. I’m using it in the very general sense of ‘the class of computers that are equivalent to the original machine in terms of what they can achieve’, as defined earlier.)
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And more on Quantum computing goodness :lol: quite a light read ;D about how Quantum Crytpo keys have been cracked by 2013 intel Xeon cpu, bounty was nice as well :), oh well boys back to the drawing board!
https://www.theregister.com/2022/08/03/nist_quantum_resistant_crypto_cracked/