I understand we cannot state with arbitrary precision the position and momentum of a micro-particle as we superpose infinite waves to create a wave packet at the exact position of the particle and hence cannot say which wave is corresponding to its momentum. This is theoretically said. Also some people say that measurement of one disturbs the other and some say it's reality.  Firstly, the theoretical explanation: why should I consider that a wave out of many superposed will give us the momentum or position? We might use another single wave which is not sine in nature and might get the results. Or why won't a single sine wave suffice? This all considers the micro-particle as wave because of de Broglie.  Secondly, the practical thing seems legit.  Thirdly, the electron must have some kinetic energy and position. It is who we are measuring and can't get it exact so why blame the electron as in theoretical concept. How we quantify the uncertainty, it must depend on the measuring device and various other factors.  I might need to edit this post based on your answer so that I can explain more clearly my thinking.  Edit: From here is what gets the measurement problem:        Text: Imagine that you're blind and over time you've developed a technique for determining how far away an object is by throwing a medicine ball at it. If you throw your medicine ball at a nearby stool, the ball will return quickly, and you'll know that it's close. If you throw the ball at something across the street from you, it'll take longer to return, and you'll know that the object is far away.   The problem i­s that when you throw a ball -- especially a heavy one like a medicine ball -- at something like a stool, the ball will knock the stool across the room and may even have enough momentum to bounce back. You can say where the stool was, but not where it is now. What's more, you could calculate the velocity of the stool after you hit it with the ball, but you have no idea what its velocity was before you hit it.   This is the problem revealed by Heisenberg's Uncertainty Principle. To know the velocity of a quark we must measure it, and to measure it, we are forced to affect it. The same goes for observing an object's position. Uncertainty about an object's position and velocity makes it difficult for a physicist to determine much about the object.   Edit: After seeing this answer one of my doubts is very well cleared, the other answers are also written and helpful:        Text: There is a definine velocity and momentum, we just don't know it.   Nope. There is no definite velocity--this was the older interpretation. The particle has all (possible) velocities at once;it is in a wavefunction, a superposition of all of these states. This can actually be verified by stuff like the double-slit experiment with one photon--we cannot explain single-photon-fringes unless we accept the fact that the photon is in "both slits at once".So, it's not a knowledge limit. The particle really has no definite position/whatever.
From what I understand, the  states that there is a fundamental natural limit to how accurately we can measure velocity and momentum at the same time. It's not a limit on equipment but just a natural phenomenon.  However, isn't this just an observational limit? There is a definite velocity and momentum, we just don't know it. As in, we can only know so much about the universe, but the universe still has definite characteristics.  Considering this, how do a wide range of quantum mechanical phenomena work? For example, quantum tunneling - its based on the fact that the position of the object is indefinite. But the position is definite, we just don't know it definitely. Or the famous light slot experiment? The creation of more light slots due to uncertainty of the photon's positions?  What I am basically asking is why is a limit on the observer, affecting the phenomenon he is observing? Isn't that equivalent to saying  because we haven't seen Star X, it doesn't exist? It's limiting the definition of the universe to the limits of our observation!
How do you make sure email you send programmatically is not automatically marked as spam? This is a tricky one and I've always relied on techniques, such as permission-based emails (i.e. only sending to people you have permission to send to) and not using blatantly spamish terminology.  Of late, some of the emails I send out programmatically have started being shuffled into people's spam folder automatically and I'm wondering what I can do about it.  This is despite the fact that these particular emails are not ones that humans would mark as spam, specifically, they are emails that contain license keys that people have paid good money for, so I don't think they're going to consider them spam  I figure this is a big topic in which I am essentially an ignorant simpleton. If-else working, switch not Escape a string for a sed replace pattern When shooting in mRAW or sRAW, how does the camera generate smaller files? Most mid- and high-end DLSRs offer two or three sizes for RAW capture.  When the camera is generating the medium or small sized RAW files, how does it make them smaller?  Does it capture less information onto the sensor?  Does it capture the full amount of information and then apply some sort of in-camera compression?  Does it do something else that I'm not describing? This is my first question in /photography. I'm a very amateur photographer, doing things wrong and by eye with lots of trial-and-error all the time.  I currently own a reflex Nikon D70 my uncle gave us after he bought a better one. It has some nice settings, and he bought a a Nikkor 28-80mm F/3.5-5.6 zoom lens for it. It behaves nicely, but it's getting old (it has those old cartridges before SD cards existed) and every new charge takes longer than the last.  I'm planning to upgrade to a better camera, and there are some neat offers on a nearby superstore (MediaMarkt), this one catching my eye:  Sony DSC-H400 63x, Sensor Super HAD 1/2/3 CCD 20.1MP -> for less than 300€ taxes included  I don't have any type of extra information aside from that, all I can get from the official site is clinical data from other cameras that I suspect it's not 100% accurate, and there's no photography expert on the store to ask.  The common things I use my D70 for are: taking pictures of scenery (castles, towns, forests, waves hitting rocks, etc...), nearby (&lt;5m) persons and objects, and well, things where I want to save a memory in digital format, not for professional purposes at all.  Being that my objective is to have a decent, good-zooming (superzoom looks awesome), amateur (but with manual settings) camera, is this Sony a good replacement? Will I miss any features? Is there any better, similarly-priced alternative you know of?  Basically, I want to know whether I will get better quality photos than I currently do, given the examples, with any averagely-priced bridge camera similar to that Sony, and if it's worth it.  examples of current camera results  Full zoom-out of town at night, bad quality I know; notice the pink blur at the left.    Maximum zoom on that pink blur from almost the same spot:    Daylight, cloudy, modified with Adobe Lightroom, scenery:    Same day, same beach, different settings:    Same day, same beach, rocks: USB stick mysteriously become write protected So, somehow over the weekend, my 1GB USB flash drive has managed to become write-protected.  There is no switch on the stick, so I'm concluding that something has corrupted at some point.  Obviously I can't format it or remove.  The output from dmesg | tail is:  Buffer I/O error on device sdb1, logical block 328168 lost page write due to I/O error on sdb1 sd 73:0:0:0: [sdb] Unhandled sense code sd 73:0:0:0: [sdb] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE sd 73:0:0:0: [sdb] Sense Key : Data Protect [current] Info fld=0x0 sd 73:0:0:0: [sdb] Add. Sense: Write protected sd 73:0:0:0: [sdb] CDB: Write(10): 2a 00 00 05 08 00 00 00 01 00 Buffer I/O error on device sdb1, logical block 328200 lost page write due to I/O error on sdb1   I think the second and final lines are a giveaway to corruption, but I don't know how to interpret this output.  Could someone help to see if this output gives any indication?  I usually eject the drive before removing it, but I may have been lax once or twice.  The data isn't critical, it's just bugging me.  Any suggestions on how to fix it (if the drive even can be) would be greatly appreciated. Update query cancelled by user Wine or virtual machine (VirtualBox) to run apps (eg. Photoshop) I am wondering if it will be better (stability, convenience and speed) to run apps like Photoshop with Wine or a virtual machine like VirtualBox? What is the proper usage of "not only... but also"? I'm trying to figure out how to use "not only... but also" properly. Basically, my goal is to combine two clauses by using "not only".  For negations, I've figured out two styles that both sound correct:   He knew that if he fractures his finger, not only would he not be able to compete in the water polo tournament, he would not be able to take the SAT on Monday, either. He knew that if he fractures his finger, neither would he be able to compete in the water polo tournament, nor would he be able to take the SAT on Monday.   However, I don't know how to form a sentence that does not include a negation while using "not only". Here are a few possibilities that I've considered:   Thanks to his remarkable performance on the SAT, not only was he accepted into Harvard, but he was also given a full scholarship. Thanks to his remarkable performance on the SAT, not only was he accepted into Harvard, but he was given a full scholarship. Thanks to his remarkable performance on the SAT, not only was he accepted into Harvard, he was given a full scholarship. Thanks to his remarkable performance on the SAT, not only was he accepted into Harvard, he was also given a full scholarship.   In those four possibilities, I'm varying the usage of "but" and "also" in the last clause.  What is the proper usage of "not only"? These should work by adding spaces or removing spaces from the beginning of the current line or every line between the start and end of a text selection (inclusive).  (edited this question to supplement ) Can I visit other Schengen countries on a long-term Schengen visa or residency permit? Does the order of declaration matter in Java/C#? In C++ I can't use a method if I declare it after the calling method.    Does this order matter in other languages like Java or C#? Why doesn't Neo teleport at random? How can I access google.com outside the US? I live in the UK, and whenever I visit google.com I am redirected to google.co.uk, but I want to see my website's rankings on the US version (I presume the results are different). Is there a way to do this? I've got a directory shared on my network, using Samba. People on the netwerk use this Samba share to download files from my share to their computers. I'm interested in what files are downloaded most, and by which users they are downloaded. I'd like to see this in real time, if possible. Is there a program that allows me to do this? If yes, how can I use it?    I'm using Ubuntu 11.10. Custom question lists April status update Previous posts:                           After a long hiatus, a new Custom Question Lists update is out with a fresh new design.  What's shipped?  If you are participating in the Custom Question List alpha (by ), you'll see some brand new UI components when viewing question lists:  New tab bar and editor    Based on your feedback, we decided to rethink the whole UI, removing some confusing and redundant components, and bringing back some much loved pieces.  The new design is closer to "the existing question lists with advanced options" than "a radically new experience".  Huge shoutouts to our new designer, , for making this new design possible and to  for picking up development while I was on sabbatical!  Some important notes for existing testers:   The summary is back in its rightful place next to the tab bar.  If bounty or unanswered filters applied, the summary provides a clearer explanation of what you're looking at, inspired by /unanswered. The "Filter" and "Sort" popovers are gone. Sort was too similar to the existing tabs, and Filter was a form in a popover. (how were you supposed to submit or cancel?)  Now there's a dedicated UI for filtering. The complex "Create" and "Edit" modals are gone.  Now you just configure your list with the same UI as if you were filtering and click "Save filter" when you're ready to save. You can preview your changes before updating a filter.  Editing a saved filter and clicking apply shows you your new options while remembering what filter you were looking at.  You can then click "Save filter" to either update your existing filter or create a new one. We handle responsive better.  The tab bar has been set up so it compresses more naturally on narrower browsers and mobile devices.   New sidebar widget    A new right-sidebar widget has been added, similar to Watched Tags, to give you more direct access to your saved lists.  This is where indicators will live in Phase 3 (which I swear we are actually going to ship).  Please give it a try.  If you have any questions, bugs, or feedback, you can reply to this post directly or add a new question with the  tag.  A wider alpha  Since we're nearing launch, we're expanding the alpha out to the whole network.  So feel free to try this out on any site you frequent, to help suss out any site-specific issues.  What's next?  As always, Phase 3 of this project is adding indicators for new content, now in the right sidebar widget.  There's increasing interest in this feature from Enterprise, so I do really expect this to ship and get out of Alpha sooner rather than later and this time, I mean it. The Density of Clouds Could we have the ability to mark a change as minor in questions or answers? It would be nice to allow users to mark a change in an answer (or question) as minor (e.g. for a simple spelling or grammar correction). A change marked as minor wouldn't push the question on top of the list of questions on the home page or in the feeds. It wouldn't trigger any notification. This could be implemented with a "Minor change" checkbox when editing an entry (a la Confluence). What do you think? Why does node not evaluate Math.tan(Math.PI/2) to Infinity but Chrome V8 does? Discriminant analysis vs logistic regression I found some pros of discriminant analysis and I've got questions about them. So:     When the classes are well-separated, the parameter estimates for   logistic regression are surprisingly unstable. Coefficients may go to   infinity. LDA doesn't suffer from this problem.      If number of features is small and the distribution of the predictors   $X$ is approximately normal in each of the classes, the linear   discriminant model is again more stable than the logistic regression   model.    What is stability and why is it important? (If logistic regression provides a good fit that does its job, then why should I care about stability?)      LDA is popular when we have more than two response classes, because it   also provides low-dimensional views of the data.    I just don't understand that. How does LDA provide low-dimensional views? If you can name more pros or cons, that would be nice.