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Scott’s Supreme Quantum Supremacy FAQ

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Re: Scott’s Supreme Quantum Supremacy FAQ

#211

Post by diegoperini »

OscarCunningham wrote: post #148
AgentME wrote: post #134

Earlier quoted context omitted.

>A bit has the storage capacity of 2 distinct bits of information. A qubit has the storage capacity of 2 complex numbers, which corresponds to 4 floats, which is at least 16*8 bits of information if we are conservative about our assumptions. This whole explanation makes qubits sound just like a combo-pack of bits, or like something you'd find in an analog computer. They're much more powerful than that because they ca…

And also, qubits can't be used as compressed data storage. Despite the fact that it takes two real numbers to specify the state of a qubit, you only get one bit out when you measure it, with the rest of the information being destroyed.

The whole point of Quantum Supremacy test is to show that qubits can in fact store distributions in their state which is another way of saying some carefully crafted equations are storable inside qubits as long as you are interested in an approximate and numeric output. One can argue a MIDI audio or a SVG graphic is exactly that, a carefully crafted equation which even in its lossy form (mp3, jpg) is able to convey meaning.

Re: Scott’s Supreme Quantum Supremacy FAQ

#212

Post by OscarCunningham »

nullc wrote: post #179
OscarCunningham wrote: post #154

Earlier quoted context omitted.

>Can it be applied to economic, environmental, traffic, etc as well? Our current understanding is that quantum computers won't offer a speedup for the simulation of nonquantum systems. The only simulations they'll be faster for are systems for which quantum effects are important. Of course it's possible that someone will discover an algorithm that gives quantum computers an exponential speedup in the simulation of an…

> Our current understanding is that quantum computers won't offer a speedup for the simulation of nonquantum systems. The speedup from grover's algorithm is essentially universal it's just not an exponential speedup. So for example in your non-quantum simulation task, you want to search for an input to a cellular automata that makes it spell your name after 5000 timestemps. You can use grover's algorithm to find that…

> The speedup from grover's algorithm is essentially universal it's just not an exponential speedup. So for example in your non-quantum simulation task, you want to search for an input to a cellular automata that makes it spell your name after 5000 timestemps. You can use grover's algorithm to find that input with a sqrt() the number of simulation runs that a classical machine would need (and perhaps fewer, since there are likely multiple solutions).

I'd view this as using fewer simulations, rather than doing the simulations faster.

Incidentally, I happen to be the author of some software for finding CA predecessors: https://github.com/OscarCunningham/logic-life-search/. Good luck getting it to do 5000 or even sqrt(5000) generations though! It's SAT solver based, so as soon as someone does invent a quantum SAT solver it'll plug right in.

> [Which is also why many of the common incorrect descriptions of quantum computing are sad, stuff like "testing all values in paralle"-- if it worked like that description it would be magic instant computing.]

To be fair, many quantum algorithms do begin by preparing a superposition of all possible intputs and then applying the unitary corresponding to some classical function. The difficulty arises when you have to extract information from the resulting output superposition.

Re: Scott’s Supreme Quantum Supremacy FAQ

#214

Post by pixl97 »

gmueckl wrote: post #185
rtpg wrote: post #177

Earlier quoted context omitted.

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. ;)

Traffic to the airport is.

Re: Scott’s Supreme Quantum Supremacy FAQ

#215

Post by rangibaby »

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.

640 qubits ought to be enough for anybody
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