Mithrandir24601

@glS I remember we once got a message from someone who was organising one of IBM's hackathons being like 'someone's asking the hackathon questions on QCSE', so it was pretty easy to verify they were who they said they were

Well, lock if we have official word from someone anyway :P

@glS we should at least lock until the deadline is up (unless it needs closed for another reason, sure)

@NorbertSchuch kind of, the policy is essentially 'judge by content, not motivation'. We've temporarily locked time-sensitive exam or competition programming questions before but that's about the extent of it

Do you mean like some kind of a partial trace of entropy or something?

@MoreAnonymous Hmm, I'm not sure what you mean by 'performing a negative entropy'?

@Vogel612 Ahhh, I see! Makes sense

Like, if we take the simplest case, where x has a bit-length of 1 and f(0) = 0, f(1) = 1. We start with the state |+-> = (1/2)(|00>-|01>+|10>-|11>), you can say that the oracle is a CNOT that takes the RHS and bit flips when the first bit is 1 to give (1/2)(|00>-|01>-|10>+|11>). You could also consider the CNOT in the Hadamard basis, which is looks completely different - if the 2nd bit is |->, it swaps the first bit between |+> and |-> yet these are the exact same operation

I mean, there's this whole thing about how oracles abstract away a lot (often too much) detail, so I wouldn't worry too much about this - the oracle is physically acting on both registers at once, so any operation it does can change either one of the registers, or both

But if the system is entangled, you're operating on a specific state, less so a specific register

If the system isn't entangled, this just gives a global phase, which you can't measure

@Vogel612 In this case though, I suppose you could say that, when f(x) = 1, it does a bit flip, but this bit flip is a basis-dependent operation, so when you apply it to |->, what you get is -|-> - but then if you have some state |a->, you get -|a->, so it's acting on 'both', if that makes sense?

@Vogel612 I'm not sure what you mean exactly by the notation x∗ and ↔?

@glS How'd you guess? :o

I can sense it XD

Did someone mention tea?

@Feynman_00 If you want to learn all the basic stuff useful for physics, you're free to go ahead and do undergrad + masters degrees in maths, CS, physics, EE and maybe chemistry while you're at it... There's a reason you don't get taught everything in undergrad

Dunno why you'd even try comparing a desktop CPU with a cloud TPU anyway :P

@JakeRose Nice! That's a great job if you can make it :D

I mean... PhD was easier than undergrad :P

@JakeRose Yep! What are you up to now then if you didn't go down the PhD route?

Ahh, yeah, I haven't done any experiments in years, I get to sit in an office and 'think' :D

@SirCumference GR is physics, QM is physics, so both should be taught in a physics course. Chemistry is a subject every bit as big as physics, so doesn't need to be taught in a physics course

@SirCumference There's only so much time in a degree...

@JakeRose Yeah, I know right! If only I knew at the time, I would have recognised it as a sign I should have gone into the astro department or something

Failed astro fluids

Ewww, I couldn't deal with astro

@JakeRose Finished my PhD a few months ago, now work on designing/researching quantum photonics :D

@JakeRose Definitely know the name, but I don't think she lectured us? Maybe one of my friends did some work with her or something?

@JakeRose Probaably some

@JakeRose Caius

and I remember the whole thing about it changing structure

But I know there have been minor changes since, cause I started off doing CS

@JakeRose Started nearly a decade ago (i.e. 2012)

@JakeRose Ahh, interesting, that'd be the equivalent version

@JakeRose It was whoever was lecturing first year maths for physics (or whatever they call it - maths for physNatsci?)

@SirCumference I agree

@JakeRose Did you get the 'how on Earth hasn't everyone done complex numbers by now?' rant in the first week as well? I still remember that one xd

This is like 3rd year of secondary school stuff...

@JakeRose ... When did you do linear algebra?

@JakeRose I'm more than willing to call any board that doesn't include matrices until further maths 'bad' :P

@JakeRose I believe it was a GCSE thing in NI when I was at school, I just can't cope with how terrible English maths is

@SirCumference Nope

@JakeRose Yeah, I still can't get round how matrices aren't universally taught in school

@ACuriousMind Drives me mad

The question I'm always asking is why basic quantum info, which is taught to school pupils on occassion, is considered a masters level subject

@JakeRose Well, I dunno, I'm not thinking in terms of the maths content, rather why they dive straight into e.g. continuous quantum systems instead of starting small and understandable

@JakeRose Dunno, you can't compare with what you didn't experience. I think it was really good in some ways but lacking in others - I know that one of my friends joined me in one of the QFT lectures in Nottingham and he said the Notts QFT lectures were much better

@JakeRose Well, it's a physics degree... What you 'need' from it is kinda arbitrary. It's physics, so teaching physics is entirely within the scope xd

@SirCumference Yeah, it would - we did classical field theory before going into QFT and that seemed to make life easier. But I'm always complaining that unis always get their QM teaching badly wrong (in terms of how they order stuff at least)