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Scott’s Supreme Quantum Supremacy FAQ

scottaaronson.com

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Re: Scott’s Supreme Quantum Supremacy FAQ

#181

Post by moyix »

smsm42 wrote: post #122
whatshisface wrote: post #4

If it goes well, the history of quantum computing will be divided up in to three eras: the era of twisty philosophical arguments that it's working ("the molecule is simulating itself"), the era of academic arguments that it's working ("we can solve this one carefully constructed problem") and the era of practical arguments ("Amazon is selling QC time for $20/kilogate-bit, what do you mean it's not possible?"). Quantu…

The third stage is the hardest. Thermonuclear energy production has been sitting in "theoretically possible, but economically unviable" for decades, tons of technologies like supersonic commercial flight has been achieved and then scrapped because of practical concerns, many other technologies struggle with passing economic viability barrier. Taking that into account, getting from 2nd to 3rd stage would be the hardes…

> Comparing to classic computers, their practical usability has been clear since Babbage time

Is this true? I thought that in the 40s-50s there was some argument over whether practical computers could really be built given that vacuum tubes were so unreliable. Von Neumann wrote gave a series of lectures in 1952 (eventually transcribed into an article) showing how it could be done: http://arep.med.harvard.edu/gmc/Von_Neumann_1956ro.pdf , and the argument became more or less moot once transistors arrived).

There's perhaps an analogy here to be made with quantum error correction, but that seems to be a lot harder...

Re: Scott’s Supreme Quantum Supremacy FAQ

#182

Post by sundarurfriend »

nexuist wrote: post #2

Preface: I know nothing about quantum computing. What exactly is a qubit? I'm not asking what does it mean, because I know there's superpositions and all that jazz, but as in...like, in an electronic circuit, what is a qubit? Is it made out of logic gates? Which ones? If we can make one qubit, can't we just make a bunch of them by copy and pasting circuits similar to how we used vacuum tubes in the 60s and 70s? How c…

Quantum computing for the very curious [1] has been very useful to me, for getting at least a basic idea as to what exactly a quantum computer is, what a qubit is, and how they are manipulated.

[1] https://quantum.country/qcvc

Re: Scott’s Supreme Quantum Supremacy FAQ

#183

Post by empath75 »

jessriedel wrote: post #82
sanxiyn wrote: post #69

Earlier quoted context omitted.

This depends on your definition of "trivial". But if we restrict it to factoring, no, there is no known path to QC factoring at the moment, none at all.

I don't understand. Factoring composite numbers into their primes is definitely a predicted use for QC in the future. Are you just saying the architecture of the machine powerful enough to do that is still uncertain?

Right but in the foreseeable future we might be able to factor numbers as large as like 24. Not 24 digits. 24 the number.

Re: Scott’s Supreme Quantum Supremacy FAQ

#184

Post by DebtDeflation »

sanxiyn wrote: post #131
calhoun137 wrote: post #68

Earlier quoted context omitted.

I am not very familiar with Scott Aaronson and am just making a general observation about the subject of QC, I have no idea what his motivations or intentions are. If Scott believes QC will day be practical and I don't, only time can tell who is right and who is wrong. I have seen this kind of goal post moving in string theory, and its been going on for 20 years with QC in a strikingly similar way imo. There is no wa…

I think Scott is agnostic about whether QC will be practical or not. To quote the original article, "we have no idea how long it will take".

>"we have no idea how long it will take"

IMO, this is a reasonable position to take. However, we have to accept that even if a universal QC is possible, "how long" could conceivably be centuries.

Our perspective with regard to technology has been significantly biased by our experience with Moore's Law/Dennard Scaling. The speed of progress in ICs from 1960 to 2010 (and especially 1980-2000) is an outlier in the history of science and technology, yet we base expectations in everything from AI to QC on it.

Re: Scott’s Supreme Quantum Supremacy FAQ

#185

Post by gmueckl »

rtpg wrote: post #177
biztos wrote: post #174

Earlier quoted context omitted.

Could the improvements in Business and First Class travel, combined with the increased use of private jets (also NetJets) have contributed to the downfall of the Concorde? The more comfortable you are in the flight, the less the actual number of hours flown bothers you.

Also the fact that airports are still a big time sink even with all the priority passes in the world. No amount of money makes getting from your front door to the airport not be a massive pain potentially taking over an hour if you have some bad luck

Passenger queues are not an issue when you are departing from a GAT in your private jet. ;)

Re: Scott’s Supreme Quantum Supremacy FAQ

#186

Post by vixen99 »

hamilyon2 wrote: post #136
whatshisface wrote: post #4

If it goes well, the history of quantum computing will be divided up in to three eras: the era of twisty philosophical arguments that it's working ("the molecule is simulating itself"), the era of academic arguments that it's working ("we can solve this one carefully constructed problem") and the era of practical arguments ("Amazon is selling QC time for $20/kilogate-bit, what do you mean it's not possible?"). Quantu…

There is market for two, maybe three quantum computers on earth.

Ken Olsen founder and CEO of Digital Equipment Corporation (DEC) in 1977: "There is no reason for any individual to have a computer in his home.”

Re: Scott’s Supreme Quantum Supremacy FAQ

#187

Post by lordnacho »

moyix wrote: post #181
smsm42 wrote: post #122

Earlier quoted context omitted.

The third stage is the hardest. Thermonuclear energy production has been sitting in "theoretically possible, but economically unviable" for decades, tons of technologies like supersonic commercial flight has been achieved and then scrapped because of practical concerns, many other technologies struggle with passing economic viability barrier. Taking that into account, getting from 2nd to 3rd stage would be the hardes…

> Comparing to classic computers, their practical usability has been clear since Babbage time Is this true? I thought that in the 40s-50s there was some argument over whether practical computers could really be built given that vacuum tubes were so unreliable. Von Neumann wrote gave a series of lectures in 1952 (eventually transcribed into an article) showing how it could be done: http://arep.med.harvard.edu/gmc/Von_…

Depends on what you mean by "computer", but being able to reliably calculate even just simple arithmetic has clear benefits. In the 1800s there would be countless clerks doing some sort of bookkeeping who'd benefit from it.

I suppose double entry would be your error correction. That also benefits from having a calculating machine.

Re: Scott’s Supreme Quantum Supremacy FAQ

#188

Post by [deleted] »

grumpy8 wrote: post #81
nexuist wrote: post #2

Preface: I know nothing about quantum computing. What exactly is a qubit? I'm not asking what does it mean, because I know there's superpositions and all that jazz, but as in...like, in an electronic circuit, what is a qubit? Is it made out of logic gates? Which ones? If we can make one qubit, can't we just make a bunch of them by copy and pasting circuits similar to how we used vacuum tubes in the 60s and 70s? How c…

Extremely simplified: >> in an electronic circuit, what is a qubit? It's not an electronic circuit, it literally is an electron or a photon. And it's using that particle's properties to do "superposition and all that jazz". You can't put too many next to each others because they start interacting together because that's what electrons do when they get close.

[deleted]

Re: Scott’s Supreme Quantum Supremacy FAQ

#189

Post by viraptor »

outworlder wrote: post #35
itcrowd wrote: post #25

Earlier quoted context omitted.

Essentially, they use superconducting electronics to create a quantum circuit. It's not the same logic gates as a traditional computer chip and not based on the same physics. The details are difficult & messy. There are several reasons it doesn't scale easily to more qubits, but you can imagine that you don't want the chip to be large (must be cooled to 25mK!) but the qubits should be spaced quite far apart so they d…

Holy hell. > > In a superconducting circuit, conduction electrons condense into a macroscopic quantum state, such that currents and voltages behave quantum mechanically [2, 30]. Our processor uses transmon qubits [6], which can be thought of as nonlinear superconducting resonators at 5 to 7 GHz. The qubit is encoded as the two lowest quantum eigenstates of the resonant circuit. Each transmon has two controls: a micro…

At the extreme, it approaches art: https://www.reddit.com/r/VXJunkies/

Re: Scott’s Supreme Quantum Supremacy FAQ

#190

Post by empath75 »

galaxyLogic wrote: post #51
3PS wrote: post #32

Earlier quoted context omitted.

Short answer, a qubit is a unit vector in a 2D complex Hilbert space. Now, that doesn't actually say much about why we care or how they're useful. In practical terms, you can think of qubits as complex unit vectors along two axes, with one axis corresponding to |0⟩ (the zero qubit) and one axis corresponding to |1⟩, or the one qubit. So for example, you could have a qubit called |+⟩, which is just shorthand for (|0⟩…

> Schrödinger's cat must be alive or dead once we open the box I recently had a conversation about this in another thread. It seems to me, and nobody tried to convince me otherwise, that the Cat would be the Observer. Therefore it would be dead, NOT dead AND alive, as soon as it observes the poisonous gas in its box.

sure but that’s still all one quantum system from the perspective of any other observer outside of the box, including other cats.
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