Wikipedia:Reference desk/Archives/Computing/2018 March 4

= March 4 =

plugins
I'm a long time Firefox user and I've been using Firefox plugins to configure customs key bindings to my liking. A couple of months ago, Firefox Quantum came out with better performance, but unfortunately is not compatible with any of the old plugins, so I've been forced to switch to Firefox ESR until the plugins authors can catch up.

It's been a while now, are there now any plugins that can re-configure custom keys in Firefox Quantum? Mũeller (talk) 02:02, 4 March 2018 (UTC)

Magnetic Effects on Amazon Kindle™?
Like most it's counterparts, the Paperwhite, has a push button on it's lower edge which makes the screensaver appear, and touch screen becomes unenabled (to make the whole thing active and touch screen enabled one has to press the same push button again ).

Recently I happened to buy a two-sided cover for this. The e-reader fits the side meant to enclose the thing fits very suitably but the problem is that when I open cover the e-reader becomes active on it's own (without any need to push the button the lower edge, and screen becomes active to touch ). Is it normal? - I strongly doubt it since the fit-the-e-reader side has a specially build space (or gap) to reach the awakening button at the precise location. Have other users using the same two-sided-cover been facing (or faced) same problem.

Mine own guess, (which maybe wrong of course) is that the culprit is the magnetic locks which are on the right-sided and left-sided edges of the book-binding-type cover respectively. When left sided cover is lifted to read, the magnet on it's outer edge passes over screen causing some electronic disturbance inside. Needless to say that doing this over and over again may cause some serious problem in the e-reader itself.

Has anyone any solutions to the problem ? Jon Ascton   (talk)  09:48, 4 March 2018 (UTC)
 * You're almost definitely mistaken. This is an intentional design on the ereader, as it is for a number of ereaders and tablets (including many iPads). It is not because of some 'electronic disturbance' unless you're using some weird definition. It happens because the device is designed with a magnetic sensor and the case is designed with magnets in the right place to activate this sensor. So you should not expected any long term consequences from using this feature. Actually there's a fair chance that using it will increase the life span of the ereader on average since physical on-off switches tend to be one of the major weak points on devices assuming you don't break the screen. If you just don't like the feature, many devices let you disable the auto-wake up (without affecting the activation of the sensor i.e. it's just ignored), but it doesn't seem Kindle devices are one of these [//www.mobileread.com/forums/showthread.php?t=254175]. So your only choice is to get a cover not designed to activate the sensor. Keep a look out for one that doesn't advertise it self as a smart or sleep cover and doesn't mention anything about auto-wakeup ..Nil Einne (talk) 11:00, 4 March 2018 (UTC)

Is it possible to simulate classical logic gates (e.g. AND gate, OR gate and NAND gate) by quantum gates?
It seems that we lack appropriate software to be run on quantum computers because quantum programming requires solid backgrounds:


 * Quantum computing is real. But it's also hard. So hard that only a few developers, usually trained in quantum physics, advanced mathematics, or most likely both, can actually work with the few quantum computers that exist. 
 * "D-Wave is driving the hardware forward," says D-Wave International president Bo Ewald. "But we need more smart people thinking about applications, and another set thinking about software tools."

If classical logic gates could be built on top of quantum gates, it could facilitate the development of software for quantum computer I guess. - Justin545 (talk) 09:59, 4 March 2018 (UTC)


 * Linking company page: D-Wave Systems. --Hofhof (talk) 01:28, 5 March 2018 (UTC)


 * Of course you can simulate them, but it would miss the point: we can already build classical logic gates for cheap and program with them easily. What D-Wave has built is not a general-purpose programmable quantum computer, but rather a specialized machine capable of solving the so-called QUBO problem.  Expressing some other problem of interest in that very limited vocabulary is what is "hard" in the current milieu.  --Tardis (talk) 05:32, 5 March 2018 (UTC)


 * OK, my original question was probably somewhat unclear. My intention was not focused on D-Wave's quantum computer but any quantum computer made by any company. So it's feasible to simulate classical logic gates on top of quantum gates according to your answer if I understand correctly. And my next question would be "Do the simulated logic gates still preserve the parallelism property of quantum gates?". For example, a 5-qubit quantum computer should be in a superposition of 32 states. Will the simulated logic gate affect all 32 states when it is applied on those qubits? (the simulated logic gate is applied once but as if it were applied 32 times) - Justin545 (talk) 10:38, 5 March 2018 (UTC)


 * The design of quantum logic gates is quite different from classical logic gates because quantum processes (up until collapse of the wave function a.k.a. measurement) preserve information, so quantum logical gates are reversible. See our articles on quantum gates and quantum circuits. You could emulate classical logic using quantum logic gates, but, as Tardis says above, it is not clear why you would want to. You would have to throw away information by making a measurement after each gate, thus losing the whole point of quantuim computing. The obstacle in quantum computing is not designing effective circuits or algorithms - it is how to maintain a sufficiently large number of qubits in an entangled state for a sufficient length of time to perform interesting calculations (more interesting than factorizing 15, for example). Gandalf61 (talk) 11:03, 5 March 2018 (UTC)

Google maps colours
Google maps standardly (on my PC anyway) shows urban roads as white on a white background. It is VERY hard to see, and I practically always flip to satellite view to get roads I can see where they are. Is there any way of configuring GM so that this doesn't happen (eg grey on white or white on grey or ...) Thanks. -- SGBailey (talk) 19:46, 4 March 2018 (UTC)
 * No. See alternatives here 93.142.115.131 (talk) 03:56, 5 March 2018 (UTC)
 * There's something odd here if the OP is really seeing roads as white on a white background. Google Maps has always shown roads as white, with the background map colour being light grey. A quick Google Image search suggests this isn't some weirdness only I'm seeing. Perhaps the OP needs to mess with their gamma or contrast settings if they're seeing white on white. Nil Einne (talk) 12:40, 5 March 2018 (UTC)
 * It is a very low contrast difference. I agree it's difficult to see especially at moderate zoom levels -- Q Chris (talk) 14:26, 5 March 2018 (UTC)
 * As to "always", they did tweak it to lower the contrast couple of years ago, and there were complaints like this at the time. --69.159.62.113 (talk) 21:44, 5 March 2018 (UTC)
 * Sure so you may have noticed a change, but it should still show up as gray and white if your contrast, brightness and gamma settings aren't unorthodox, and display isn't broken. The gray may be fairly light, and you can debate whether or not it's a good colour scheme, but it should not be white on white. If you want to keep your unorthodox settings or your broken display, that's not our business, but you should at least be aware that it isn't supposed to be white and white and the reason is partly because of your unorthodox settings or broken display. Nil Einne (talk) 10:34, 7 March 2018 (UTC)
 * "Broken" may be a bit strong, but it could be defective. This image makes a nice little test.  On my monitor, after the words "daily dose of imagery" and a space, there is a line of 27 squares shading from white to black, and every one of them is distinguishable, at least if I enlarge the image a bit.  I remember that with a previous computer I could not distinguish about 5 or 6 of the squares at one end of the scale, so I knew that it was not a good screen for viewing high-grade images on, even though it was fine for ordinary text.  --69.159.62.113 (talk) 19:14, 7 March 2018 (UTC)
 * This you try adjusting the brightness and contrast of the display or perhaps gamma (whether with display controls or computer controls)? It sounds to me like that could have been simply the issue. By 'broken' I was thinking of old displays, particularly CRTs that are now so old they can no longer properly display a reasonable gamut, I personally consider this broken although maybe not everyone would agree. While it's true that display quality can vary greatly, the thing with the Google Maps issue is that even now while the contrast may not be as high as some people would like, I think it's high enough that you don't need a high end display, or even a mid end display to see the difference. Or to put it a different way, I could be wrong, but I have a hard time imagining many new displays could not at least display the difference between the white and gray used for Google Maps when properly set-up. (I'm not saying it will be super high contrast, but at least enough to notice that it's gray not white.) A small number of displays may come out of the factory so bad that they will only end up in as some ultra bargain display in the lesser developing world. (In other words, the display is so bad that even in the lesser developing world it's not the norm.) I guess you could debate whether this is 'defective', 'broken' or okay. Oh and by 'properly', I'm thinking of calibrating according to what will be commonly recommended by tools etc used for the purpose and in an environment where it's suitable. The last bit is one thing my earlier replies didn't really touch on. If for example you're using a glossy display in a fairly bright environment which it isn't really designed for, you may need to adjust the settings so that you can at least read most normal text etc properly. These settings may very well screw up the contrast enough that you won't be able to see the difference between the the white and grey in Google Maps. (The other possibility as I hinted at assuming the settings are intentional is you just don't like the recommended settings. And as I did mention, if you have no particular reason to prefer the settings you're using, you probably should try and adjust them. Even simple online tools would be better then nothing.) Nil Einne (talk) 01:38, 8 March 2018 (UTC)