(Part 2) Best mainframes & minicomputers books according to redditors

Social engineering is considered a form of hacking from what I remember of the CompTIA Sec+

People outside of tech have a wildly narrow definition of that word.

This book is not full of leet hacks, just quick and dirty tricks for sysadmins: Linux Server Hacks, Volume Two: Tips & Tools for Connecting, Monitoring, and Troubleshooting https://www.amazon.com/dp/0596100825/ref=cm_sw_r_cp_apa_48tNBbPJM2JVJ yet I am told all the time that "that's not hacking"

> Kay, I just learned it as QP.

Tell Moorthy I am very disappoint.

> By a brief look at BQP, BQP = RP, right?

Not quite. Here's a quick rundown of relevant complexity classes

• P : Anything that can be solved deterministically in polynomial time (roughly speaking).
  
• NP : Anything that can be verified deterministically in polynomial time (roughly speaking).
  
• Co-NP : Anything that has certificates of no solution that can be checked in polynomial time (roughly speaking). A simple example is giving prime factors of a number as a certificate of its nonprimality (ignoring for now that PRIMES is in P).
  
• RP : The set containing any language L for which there exists a randomized TM such that, when run on an input x... (1) the TM always returns False if x is not in L (2) the TM returns True at least 50% of the time if x is in L (the choice of 50% doesn't matter here, since any non-negligible function, including constant functions, can be amplified to 50% in at most polynomially many rounds).
  
• Co-RP : The same as RP, but with the asymmetry between True and False swapped (always accept True, reject False at least 50% of the time)
  
• BPP : The set containing any language L for which there exists a randomized TM that gives the correct answer at least 66% of the time regardless of veracity (this 66% is arbitrary, but it must be at least 50% plus some non-negligible function). This contains both RP and Co-RP, since both are correct 100% of the time in one case and we can amplify the probabilities in either beyond 50% in the remainder of the instances. The B in BPP stands for bounded to separate it from...
  
• PP : The set containing any language L for which there exists a randomized TM that gives the correct answer more than 50% of the time. For instance SAT is trivially in PP, since we can use the following algorithm: (1) with 50% probability, output True or False uniformly at random (2) otherwise, pick a random assignment for the instance and output whether or not it satisfies the instance. The probability of correctness here is exponentially close to 50%, but it is still larger than it.
  
  Another way to think about these classes above are as machines that has two inputs, x and y, the latter which is chosen uniformly at random, and does the following (all probabilities are over the random choices of y)
  
  
• P : Disregards y and outputs True iff x is in L.
  
• NP : Outputs True with nonzero (but possibly negligible) probability if x is in L, outputs False if x is not in L.
  
• Co-NP : Outputs False with nonzero probability if x is not in L, outputs True if x is in L.
  
• RP : Outputs True with nonnegligible probability if x is in L, False if x is not in L
  
• Co-RP : Outputs False with nonnegligible probability if x is not in L, True if x is in L
  
• BPP : Outputs the correct answer at least 66% of the time.
  
• PP : Outputs the correct answer more than 50% of the time.
  
  There's also another way to think of these in terms of number of accepting paths in some nondeterministic TM, but this is getting overly long. Anyway, the closest class here to BQP is BPP, since they both simply aim for 66% correctness. However, the set of operations the TM is allowed to make is rather drastically different, and definitely not something I can fit in a reddit comment. Arora & Barak explains the basics of quantum computation decently. This small book can be had essentially for free off of the Amazon marketplace. It's not great, but it's much better than some other theoretical CS textbooks that might get shoved down your throat (cough Motwani & Raghavan cough).
  
  Anyway, for what it's worth, although it's strongly conjectured that P != NP, it's weakly conjectured that P = BPP despite the fact that we don't even know the relationship between BPP and NP yet (that RP is a subset of NP is known, though, and is obvious from the second set of definitions above). IIRC, most people believe P != BQP, but there's no real solid evidence for that yet.

By series of blog posts at decodoku.blogspot.ch explains things without much maths. But for the full treatment, perhaps start with
https://arxiv.org/abs/quant-ph/0110143
and work up to
https://arxiv.org/abs/quant-ph/9707021

If you'd rather have a text book, try
https://www.amazon.co.uk/Quantum-Error-Correction-Daniel-Lidar/dp/0521897874
Multiple chapters of this can be found for free on the arXiv.

Regarding 10, anything beyond small numbers is pretty much the same as far as the error correction problem is concerned. So 10 was chosen because everyone knows their 10 times table ;)

In a sense, yes. Essentially, a quantum state represented by a vector in an n-dimensional vector space, where n is the number of simultaneously orthogonal basis states the system can take (you can think of this as being the number of (distinct) polarisation states, energy levels or (basis) spin states of the system, but it's a bit more general than that). These abstract quantum states are realised by physical systems, and distinct physical systems can realise the same abstract state (such as the qubit examples I gave above).

The idea behind quantum teleportation however is not to transpose states from one type of system to another (while this is theoretically possible (and why I questioned your initial post), it may not be practical to perform the necessary Bell state measurements/set up the initial entanglement required as part of the protocol). Rather, methods already exist which allow an ion qubit state to be mapped to a photon; I just used it as an example of two systems that can take the same abstract state.

One of the uses of quantum teleportation is to be able to transport states between two quantum computers (or two parts of a quantum computer), where the initial particle is a qubit in the first computer, and the target particle a qubit in the second computer. Another use is in quantum dense coding, which allows us to transmit two classical bits of information with one qubit. Because teleportation preserves any entanglement of the initial state (entanglement swapping), yet another possible use would be a quantum exchange (see fig 15.8 in the preview of this book), which allows two people who have never met to establish entanglement between particles in their possession, through a third party.

So, I've been googling around. Here is a dump of links for those interested:

• Agner's blog/website
  
• Agner's book on optimising c++
  
• Intro to high performance computing book
  
• Efficient programming by Michael Hanke
  
• High Performance Computing - Programming and Application book
  
  
  I'll keep adding to this list as I find things.

The good thing about quantum information is that it's mostly linear algebra, once you're past the quantization itself. The good thing though is that you don't have to understand that in order to understand QI.

There are books written about quantum computing specifically for non-physicists. Mind you, they are written for engineers and computer scientists instead and they're supposed to know more maths and physics than you as well. Still, you could pick up one of those, e.g. the one by Mosca, or even better the one by David Mermin.

There are also two very new popular-science books on the topic, one by Jonathan Dowling, Schrödinger's Killer App, and one by Scott Aaronson, Quantum computing since Democritus.

The Ultimate Beginner's Guide to the 555 Timer: Build the Atari Punk Console and Other Breadboard Electronics Projects

I started reading this book back in the late 70s while still in high school. Microprocessors had just become a thing in the early 70s, and this book was a really good overview.