kernal42

kernal42 t1_j2hk0s2 wrote

Reply to comment by kernal42 in can someone explain the difference between quantum computing and classic computing in simpler words? how can quantum computing benefit us from a consumer perspective? by village_aapiser

To add, more seriously, there are other quantum algorithms that would revolutionize (or disrupt) our lives as we know them. The most obvious example is Shor's algorithm which, as Grover's above, can factorize numbers more efficiently than we know how to with classical computers. This matters because a majority of public-key encryption algorithms rely on the difficulty for factorization of large numbers. If/when someone figures out how to build a large enough quantum computer, all messages sent with this encryption (future or past) will be trivially decrypted. This breaks so much.

NB we should all be using elliptic curve public key cryptography because there's no known quantum algorithm to break it (yet?).

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kernal42 t1_j2hjf1w wrote

Reply to can someone explain the difference between quantum computing and classic computing in simpler words? how can quantum computing benefit us from a consumer perspective? by village_aapiser

Consider searching for an item in an unsorted list of length N. There's no classical algorithm that lets you find your item in fewer than N/2 queries, on average. This probably makes sense naively.

Grover's algorithm, a quantum computer algorithm, can find your item in sqrt(N) queries.

This seems impossible, but it works because quantum computing Is fucking magic.

Edit: had algorithm name wrong.

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kernal42 t1_j112sil wrote

Reply to How would we get about traveling through deep space? by MysteryMystery305

>Even at the speed of light, it would still take 4 years to travel to the nearest star system (Alpha Centauri). You can’t just yell “Hyperspeed, Chewie!” and travel through large distances instantaneously, because it’s just not possible.

That's not true. It would appear to take 4 years from Earth's perspective to reach Alpha Centauri while traveling at the speed of light....however in your reference frame (as the traveler, at the speed of light) it would be instantaneous! This is the weirdness of special relativity.

Source: PhD in astrophysics.

Of course, it will probably always be impractical to travel fast enough for this sort of time dilation to be significant, so do refer to the other responses in the thread for the practical answers.

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kernal42 t1_is17ts9 wrote

Reply to comment by Synaps4 in Does the initial pressure wave of a nuclear explosion already carry radioactive contaminants? by Freak_at_war

This is correct. Waves (including pressure waves) don't transport particulates. When I sing, the air in my lungs does not get transported into the ears of those who hear me. By the same token, if my house's windows get blown out by the shockwave of a nuclear blast there won't (yet) be any radioactivity from the blast deposited in my house.

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