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Where can I actually learn about quantum computers? I understand the meme basics, but I want to go deeper.
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computers arent science
goes in al fields
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>>13745734
Have you tried looking for textbooks on libgen?
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>>13745734
>Where can I actually learn about quantum computers?
Why do you want to waste time on that?
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>>13745764
I'm sick of sounding and feeling like a nitwit in front of my peers.
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i think if you want to read a bunch of bullshit lies on why quantum computers are “totally going to happen bro” then Scott Aaronson has a blog filled with all the delusional crap these guys shill.
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>>13745817
Only luddites/retards would think quantum computers are impossible
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>>13745835
i think Bob Laughlin and Gerard t Hooft have both argued that quantum computers will never outperform classical computers, in principle. and they both won Nobel prizes in physics

i am not as extreme, but my opinion is that the technical challenges that quantum computing is up against means they will not be able to go beyond a few (say 20-40) qbits for hundreds of years, even using the very questionable “quantum computing technologies” that exist today (which are arguably not really quantum computers at all)
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>>13745850
Well, they didn't win Nobel prizes for that. 't Hooft also promotes his own deterministic version of quantum mechanics which almost no physicist other than him accepts.

>which are arguably not really quantum computers at all
And why are they not quantum computers? You could argue that they're not very useful computationally but that's not the point here
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>>13745856
I mean: *his own deterministic version based on cellular automatons
Lots of people accept the deterministic many worlds though
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mr scientist
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>>13745856
>>13745859
regardless of what ‘t Hooft has said, i think Laughlin’s argument is sound. if you want to argue Laughlin’s opinions, i think those are more close to home

>Why are they not quantum computers?
because the way they operate is analogous to building a mini model of the problem you want to solve and then doing a measurement on the model system. it’s not like you can write an arbitrary piece of code to run on these things and enjoy the benefits of quantum computing unless your code happens to have some optimization that coincides with some quantum physics experiment that can be mini-modeled.

i think an easier way of explaining this is just to simply point out that if quantum computers supposedly exist already, then why aren’t they being used? the only applications so far are very very toy problems. why haven’t these things been employed to solve any real problem yet? after 40+ years of research?
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>>13745887
You're arguing that not very useful currently. Everyone knows that. That's different from claiming that they're impossible to construct, even in principle. I don't know what Laughlin has specifically said about this, but Aaronson seems to discuss his objections here: https://www.scottaaronson.com/democritus/lec14.html
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>>13745911
i already said that Aaronson’s blog is just a collection of the bullshit junk quantum computer true-believers tell one another. citing him is like citing the Pope on arguments over papal infallibility
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>>13745918
Well, I could say the same about Laughlin or whoever. The point is that there's no reason to believe they're theoretically impossible.
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>>13745734
they're hard to learn about because if you stop looking at one it stops existing
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>>13745941
in that case i would point out that experimentally they are a huge failure. three to four decades of trying, and basically nothing

somehow QC is treated with respect, still, somehow, but to me it looks like it had been at least as big a failure as Cold Fusion even though QC has gotten at least two more decades of failed attempts than cold fusion did
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>>13746004
Thee decades is nothing. Mathematicians have been trying to prove the Riemann hypothesis for almost two centuries and still haven't succeeded.
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>>13745734
literally dead field.
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>>13746211
yeah for /sci/ whos science and not computers lmao dumb scientist
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>>13745734
>Where can I actually learn about quantum computers?
Some very protected IBM lab. The thing with quantum computers is they are crazy expensive and require near absolute zero temps. You may read some papers, but that will not get you far. Wait five more years.
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>>13746226
>>13745734
IBM does internships in QC. There's also Qiskit open textbook if that's not too "meme basics" for you.
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Quantum computers won't scale. Some brilliant madlad is gonna prove the noise is impossible to overcome.
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>>13746004
>in that case i would point out that experimentally they are a huge failure. three to four decades of trying, and basically nothing
this is entirely incorrect and I have no idea where you get that information from
They've been slowly adding more and more capacity and capability, I recently used IBM's 53 qubit QC for a paper
In the last few years even, they've developed QC-specific languages (Pennylane [what I use], Q#, QISKit, strawberry fields, etc etc)
You yourself can literally submit a program to be run on some of the lighter QC at this very second. It's free to the public to use, your code with be Q'd during downtime (since they need to constantly keep the computer on and cold, they figured when there is scientific downtime, they might as well let other people use it)
We had some really nice papers in the past few years relevant to my field (ML), and particularly single-qubit re-uploading was something we just investigated a bit of in comparison to classic ML; anymore than that and you could easily identify me.
IBM last year unveiled a roadmap to a 1000 qubit computer by 2023, and it's not some ridiculous "we'll cure all disease in 100 years!" Zuckerberg nonsense.
While the general public is reading massive click-baity "QUANTUM COMPUTERS WILL NEVER WORK HERE'S WHY" and arguing over-generalized shitty arguments (what does "QC will never outperform classic computers" *actually mean*? Because I can immediately think of a use-case where the current QC performed calculations that classic computers could not in our lifetime), there's a lot of biotech/VC waiting to pull the trigger on mass-investment when the capabilities get there.
>>13746489
IBM's 5-qubit computer is free to use for the public.
>>13745734
https://quantum-computing.ibm.com/composer/docs/iqx/guide/
And also "Learn Quantum Computing with Python and Q#". There's also a like 10-20 year old QC textbook which is what I learned through, very approachable but I can't find the damn thing.
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i luv IBM, but i wouldnt trust them as my only/main source of quantum computers btw
they/theirs are seriously weak by modern standards
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>>13745734
Many universities offer quantum computing/information courses as electives, usually through the physics or EECS department (and very often jointly with both).
On your own, just read Nielsen and Chuang and/or John Preskill's notes. If you're comfortable with linear algebra it will be straightforward, if you're not then learn linear algebra properly first. Once you've established the basics you can delve deeper into certain theory or experimental topics.
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>>13748238
someone else here, where can i learn linear algebra?
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>>13748251
dont, for a start
its not real. math is fake - a lie. it literally does not exist, and there is no need for it anyways. once you understand that you can work on the concept of existence and do some (non-math) research from there, free from math

tell me, anon
is "math" and "maths" the same thing? its a plural, and yet the plural is not "more than one" of what it is. what is it, then?
the plural of it is something else entirely? no its not. math is an absolute joke and youre the biggest clown for believing its lies.
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>>13748251
I just googled "quantum computing linear algebra" and this Appendix showed up: https://cds.cern.ch/record/1522001/files/978-1-4614-6336-8_BookBackMatter.pdf
Seems pretty good from a quick skim in terms of content - it has pretty much all the LA concepts you need for most quantum theory. It is somewhat terse though, being just an Appendix to a larger book (not sure what that is though, sorry), so if you need more explanation you can try looking up the topic under an actual math textbook, like Strang, or even wikipedia.

The reason I don't recommend using Strang straight-up is because there's really no point in going through an entire math textbook just to be primed for physics. You don't need to waste time learning how to do Gaussian elimination, for example. On the other hand, physics math methods books like Boas are trash and should be avoided (Arfken is okay but still not great).
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>>13745734

well how much do you already know? I mean are you actually a physics student or just some interested amateur? Do you have a background in linear algebra? Dirac notation? Quantum 101?
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>>13745941
QC is not failing though, its progressing. We are already reaching the 100s of qubits regime, which should prove useful in limited cases. A universal QC may be decades away but the drive to build one will continue because there are real benefits to having one and 1000s of very smart people are determined to make this succeed.

It is not fair to compare QCs to fusion either because the physics of implementing a QC is understood far better than the plasma physics to implement nuclear fusion.

That said, I think a lot of the small QC start-ups are going to die before they realize anything profitable.
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>>13747368
There are numerous error-correction codes which show they can though?
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>>13745734
Daily reminder: ginger gf best gf
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>>13745734
start with the only good tech youtube channel
https://youtu.be/wRKc_ilWcao
and then investigate further from there
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>>13745734

Conclusions
The gigantic field of “quantum computing” with many thousands of active researchers, hundreds of thousands of publications, numerous conferences and workshops, daily announcements of new breakthroughs, and many, many billions of dollars spent, has been triggered by Shor’s invention of his famous algorithm for factoring extremely large numbers (thus eventually opening the door for quantum computers to break security codes), and by the developments of methods for quantum error correction, which is generally considered as being absolutely indispensable.

The worldwide quantum computing euphoria and the general excitement are going on already for a quarter of a century! Before engaging further for another 25 years, it might be wise to have a look at the achievements reached to date during this period.

The observable outcome can be summed up as follows:
• Factoring the number 15 by Shor’s algorithm is still not possible.
• Error correction has still never been achieved, even on a very small scale.
• No quantum device exists, capable of doing elementary arithmetic, like 3 × 5, or
3 + 5.

Thus, after a quarter of a century, there are absolutely NO meaningful results in
quantum computing!
• The only working quantum machines to date are those introduced by the D-wave Systems company in 1999, and currently intensely studied and developed by Amazon, Google, IBM, and other tech giants, as well as by the D-wave company itself. These machines can perform quantum annealing but so far are not capable of error correction and thus are NOT quantum computers in the original sense of this term. They too are not capable of factoring 15, nor calculating 3 + 5. However, they are interesting from the scientific point of view and allow to obtain some valuable results [30–33].
• With no clear reasons to believe that this situation is going to change during the next 25 years, the perspectives of quantum computing appear to be extremely doubtful.
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>>13748814
>• No quantum device exists, capable of doing elementary arithmetic, like 3 × 5, or
3 + 5.
math isnt real is the why
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a quarter of a century and no meaningful use for 3+5 or "8" - interesting as "8" is for "life" and "infinity" - a poor attempt at trying to force life into it, or use "infinity" for "big number" instead of what infinity means and is for this particular tech. its not numbers!
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>"bbb-b-b-bbut numbers arent infinite!" says the science-man and math/numbers
exactly! but 8 is. and numbers arent - the "states" are both there

this isnt science! not /sci/ - scientists should keep their nose out of technology, mr. scientist.
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>>13746211
>>13745817
Actually retards.
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>>13749043
>>13749133
>>13749146
actual big smart.
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>>13748814
>3 + 5
=
>4 x 2
> -1
7...
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>but you need to +1 for the other side
no you dont because numbers arent real
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computers arent science
--- goes in al fields
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Why don't you understand quantum mechanics bro

Its easy bro
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>>13746004
>experimentally huge failure
???
We have gotten so much research in optics, superconducting qubits, etc. out of this and have made noisy quantum computers, which have their own uses despite not being a full error corrected UQTM.
I think laughlin is intimidated that the culture is dominated by theorists despite having a strong experimental component. I share that concern but also think most scientists in the field, whether theorist or not, computer scientist or physicist, have done really useful work on the front. Hell the amount of quantum information and correlation research we’ve gotten from the CS side that’s been useful on the physics side makes it already worth the work



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