Not sure if I framed below question properly, let me know if anything you want me to clarify in the comments.  Implications of double slit experiment show concious observation affect the 'reality as we know it' on bigger scale of Einsteins relativity.  Consider below scanarios(Lets assum the detector of type magnetic needle detector)  Scenario 1. Detectors Off + Recording Off(No paper for recording, needle movement On) => Interference pattern  Scenario 2. Detectors On + Recording On => Expected two band pattern  Scenario 3. Detectors On + Recording Off(No paper for recording + Needle movement On) => Interference pattern  When we perform the experiment with the "detectors on" but the "recording off" shows the same results as if detectors are off.    Now when recording if off(no paper for recording) the needle still moves and has effect on correcponding air molecules come in contact with the needle and as per law of conservation of information, information can still be recovered.  If law of conservation of information is correct then we would have seen the same effect for Scenario 2 and Scenario 3. So do above result contraict the law of conservation of information?  ====Update  If we say magnectic needle affecting air molecules cannot be recovered that means information is lost which is against conservation of information theory.   Also if system decides(whether to produce defraction pattern or two band pattern) based on our capabilities of recovering the information then how does system know our capability of what information can be recoverd by us ? If in future we become advanced enough to be able to recover that information will the scenario 3 produce defraction pattern ?  -- The question "The Double Slit Experiment - delayed measurement " does not deal with law of conservation of information which is specifically I am acking about.
I'm not a physicist; I'm just curious about what would happen.  According to this video "" (at 2:50):     "Somebody decided to leave the detectors on but just not take any data. [...] So if it was also going to a magnetic tape - there was no magnetic tape loaded. [...] And what do you think happed? They got this. They got the diffraction pattern."   So the act of measuring (beeing concious of the data) destroys wave-form pattern?  If so lets consider these cases:   What if I'd throw a dice after the experiment to decide if I should look at the data or to destroy it? (e.g. look at the data if the number on dice is even) What if the information about measurement would need to travel longer period of time than the particle would need to hit the wall?    To above cases: Would it mean that information travelled instantly - faster than light or that "the particle can look into the future"?
"can't" versus "couldn't", what is the difference? That can't be Obama at the door, it's too early.  That couldn't be Obama at the door, it's too early.    What is the difference between them? Are they almost the same? Did Dumbledore know that Harry would have to sacrifice himself from the very beginning? Based on the following interchange between Harry and Dumbledore in the pivotal &quot;King's Cross&quot; chapter of Deathly Hallows, I was wondering when exactly Dumbledore put together that Harry would have to die in order to bring about Voldemort's ultimate demise:  &quot;And you knew this? You knew--all along?&quot; &quot;I guessed. But my guesses have usually been good,&quot; said Dumbledore (Deathly Hallows, 599, hardcover).  The conversation that spurred Harry's question includes material dating back to Halloween '81, but also specifically mentions the events of the graveyard from GoF. So, &quot;knowing all along&quot; could refer to everything (i.e., Harry must die, Voldemort ignorantly tethered him to life, etc.) or just that Voldemort tethered him to life. Other important information pertaining to this question can be found in OOTP, when Dumbledore confirms (if he didn't already know) that Harry contains part of Voldemort's soul. He uses the silver instrument to find out that Harry is just like Nagini, having the ability to share mind and soul with Voldemort. He also says the following:  &quot;I guessed, nearly fifteen years ago,&quot; said Dumbledore, &quot;when I saw the scar upon your forehead, what it might mean. I guessed that it might be the sign of a connection forged between you and Voldemort&quot; (Order of the Phoenix, 826-827, hardcover).  While confirming that he guessed that Harry might share a connection with Voldemort from the very beginning, Dumbledore does not confirm with this statement that he knew Harry would ultimately have to give up his life. In Philosopher's Stone, when Dumbledore drops off Harry on the Dursley's doorstep, we know he is not entirely truthful with McGonagall.  McGonagall asks: &quot;How in the name of heaven did Harry survive?&quot; &quot;We can only guess,&quot; said Dumbledore (Philosopher's Stone, 12, hardcover).  Of course, this was a lie. Dumbledore already knew how Harry survived, otherwise he wouldn't be delivering Harry to Lily's sister to extend the blood sacrifice. By proxy, he also knows that Voldemort will return b/c of Horcruxes, otherwise he wouldn't be so worried about Harry. Finally, when asked in the same scene if he could remove the scar, Dumbledore says:  &quot;Even if I could, I wouldn't. Scars can come in handy&quot; (Philosopher's Stone, 15, hardcover).  So, did Dumbledore know at this very moment that Harry would have to die? Did he at least guess it to be true during this scene? We know he gains perfect confirmation in OOTP, but did he know it &quot;all along,&quot; as a particular reading of the King's Cross interchange in DH would have us believe? Were these other people Chronicoms? We know that Enoch is a Chronicom, which is to say a sort of alien temporal observer.   When Enoch and his agents came and kidnapped       Coulson’s team,   for the purpose of sending them where they wanted; were these other agents also Chronicoms? I’m inclined to think they must have been (would Enoch have shared their advanced technology and goals, etc. with mere mortals), but on the other hand only one pod was mentioned. I would like to toggle the Do Not Disturb in the notification center with a keyboard shortcut.  I am using BetterTouchTool for some extra keyboard shortcuts but it does not support enabling/disabling the notifications in the default options.  It has an option for executing a terminal command so I'm asking here how to enable/disable Do Not Disturb from the terminal?  I found  and I tried to run the commands but it didn't seem to work. How did Amix Group get this helicarrier? In Deadpool,       A big fight scene takes place in a battered helicarrier at an Amix Group scrap yard.     What is the history of this particular helicarrier? And why in particular was it sent to the Amix Group scrap yard? When can you build up all representations from the fundamental and antifundamental ones? Under what conditions can you determine all representations of a Lie algebra from the fundamental and antifundamental ones using just the tensor product, direct sum and Clebsch-Gordan decomposition? I think this is true for $\mathfrak{su}(2)$ and $\mathfrak{sl}(2,\mathbb{C})$, or at least that's what physics books lead me to believe!   Is it true in general for semisimple Lie algebras? I find it intuitive enough that the radical of $\mathfrak{gl}_n\mathbb F$ is the scalar matrices, but I have trouble finding an easy, but complete proof:  Proof. Let $\mathfrak s$ denote the scalar matrices. Clearly $\mathfrak s\subset\mathrm{rad}(\mathfrak{gl}_n\mathbb F)$. Suppose that $\mathrm{rad}(\mathfrak{gl}_n\mathbb F)$ is generated by more than one element, so that $X\in\mathrm{rad}(\mathfrak{gl}_n\mathbb F)$, but $X\notin\mathfrak s$. We can change basis such that $\mathrm{rad}(\mathfrak{gl}_n\mathbb F)$ is upper-triangular. (The change of basis leaves the scalar matrices invariant.) Then $X$ is upper-triangular.  I want to conclude that there exists a $Y\in\mathfrak{gl}_n\mathbb F$ s.t. $[X,Y]$ is not upper-triangular. How can I see that $Y$ always exists, except by waving hands? Are there any rules related to the creation of a ?   I am aware of the creation method for the amulet. But I'm asking about creating the actual construct. Ping a site in Python? Duplicate questions on other SE sites? I recently asked a  on security.stackexchange.com. The question was related to XSS so in my opinion it belonged to the security website.  There was a comment on the question saying that a similar question exists on SO and my question was a duplicate (I think he gave it a down vote). The guy was right but the question was asked on another website (SO). There may be a case when person asking a question might not have an account with the other website.  Is it a good practice to mark questions duplicate if you have seen a similar question on some other website? I would that the images would appeared for each overlay. Eg, in overlay 1 I have img1.pdf, in overlay 2 I have img2.pdf, and in overlay 3 I have img3.pdf. How I do this?  \begin{center}   \begin{tikzpicture}     \node (img1) {\includegraphics[width=.5\linewidth]{img1.pdf}};     \pause     \node (img2) {\includegraphics[width=.5\linewidth]{img2.pdf}};     \pause     \node (img3) {\includegraphics[width=.5\linewidth]{img3.pdf}};   \end{tikzpicture} \end{center} Creating an arbitrary state of the quantum simple harmonic oscillator Are collective nouns always plural, or are certain ones singular? I would like some help with this exercise.  Suppose that $f_1,\ f_2 \in V^*$ and that $\text{Ker} f_1 = \text{Ker} f_2$. Show that $f_1 = k f_2$ for some scalar $k$.  I expect your suggestions.  Thanks! How to remove redundant {} from a nested list of lists? Access pictures from Pictures app in my android app Just like the iPhone has a UIImagePickerController to let the user access pictures stored on the device, do we have a similar control in the Android SDK?  Thanks. Preloading images with jQuery I'm looking for a quick and easy way to preload images with JavaScript. I'm using jQuery if that's important.  I saw this here ():  function complexLoad(config, fileNames) {   for (var x = 0; x &lt; fileNames.length; x++) {     $("&lt;img&gt;").attr({       id: fileNames[x],       src: config.imgDir + fileNames[x] + config.imgFormat,       title: "The " + fileNames[x] + " nebula"     }).appendTo("#" + config.imgContainer).css({ display: "none" });   } };   But, it looks a bit over-the-top for what I want!  I know there are jQuery plugins out there that do this but they all seem a bit big (in size); I just need a quick, easy and short way of preloading images! How precisely do I need to post close to 7:00 (somewhere) to get hero of time? How do I specify unique constraint for multiple columns in MySQL? I have a table:  table votes (     id,     user,     email,     address,     primary key(id), );   Now I want to make the columns user, email, address unique (together).  How do I do this in MySql?  Of course the example is just... an example. So please don't worry about the semantics. How many subgroups of order $n$ does $D_n$ have? How many subgroups of order $n$ does $D_n$ have?  My work:  Since subgroups of $D_n$ are either cyclic or dihedral, the subgroups of order $n$ of $D_n$ are $\left&lt; r \right&gt;$ (cyclic) and $D_{n/2}$ (dihedral). However, this works only for $n$ is even and $n\geq 2$. I don't know how to do when $n$ is odd.