I have a folder that gets filled with large files that I want Time Machine to remember while retaining the option of regularly forgetting these large files. For this and up until Catalina I would regularly enter Time machine, go to this folder and use the command Delete all backups of... (see for instance the screen capture of @Inder 's answer in ). As of my recent upgrade to Big Sur I no longer see this contextual menu option. Is it gone from MacOS for good? Is there an alternative that does not involve under-the-hood sudo-type terminal surgery? Thanks! PS. I had a look at  but the issue, as I understand it, is different. I am looking for a way to delete all backups of a given folder, not a single backup (snapshot) of the whole system. Answers that call for bypass look a bit too scary for my taste.
I'd like to delete a file from my Time Machine backups, but there seems to be no option to do so in the Big Sur version of Time Machine. I go to the Time Machine menu and select &quot;Enter Time Machine&quot;. Then I see the view with the stack of windows. I browse to a file and select it. Now I want to delete it so it doesn't exist and take up space in backups. There is no option to delete it - either the action menu in the toolbar, or the control-click context menu. How do I delete a file from Time Machine backups? There used to be a way to do this. (I'd take a screenshot, but the key shortcuts for screenshots don't work in Time Machine. Not sure if this is just a Big Sur thing or if that's always the case.) Update: I should mention I'm using APFS for my Time Machine volume. That seems to be relevant. Also, I contacted Apple support about deleting entire snapshots (slightly different goal than the one here in this question). They said you can't do it anymore. It seems like there's some bugs here, because I have a &quot;Move to Trash&quot; option if I control-click one of my backups. It seems to work initially but then the backup comes back.  I don't like losing this much control over my files. I may look for another backup solution.
Windows 7 stuck on CLASSPNP.SYS I'm running Win 7 x86 on a Lenovo Thinkpad Z61m in dual boot mode with Win XP, both OSes are running on separate partitions. I have a faulty battery and if left unplugged my laptop shuts usually down within 10 minutes. Last night, it shut down due to this, but after plugging in AC power and starting back up I'm stuck at the "Starting Windows" screen, I'm unable to boot into safe mode or into recovery mode(XP boots fine).  I believe I had installed some Win 7 updates the same/previous day. From one of the boot options I was able to see that Windows 7 is getting stuck on CLASSPNP.SYS  How can I go about fixing this?  I do have a complete Win 7 Restore CD that I created after setting up my machine, I'm unable to boot into this either.  Please help! "reflect" vs "reflection on" or "reflection of" The bride's elegant dress reflected her good taste. The bride's elegant dress is a reflection on her good taste. The bride's elegant dress is a reflection of her good taste.  Would you tell me if they mean the same thing? If they would mean the same thing, what about the following question--link--? or I mean how could we distinguish such a distinction between these functions? Similarly, what about these:  A student's grades reflected her teacher A student's grades are a reflection on her teacher A student's grade are a reflection of her teacher  When, where or in which situation don't they mean the same? How can we distinguish such a distinction? Where is "Connect to Server" for ssh connections in Unity? Cannot find "connect to server" in 11.04, looks like unity doesn't have it. Is there other very similar way to connect to another Ubuntu computer via SSH? (not in terminal) What does if __name__ == "__main__": do? Given the following code, what does the if __name__ == "__main__": do?  # Threading example import time, thread  def myfunction(string, sleeptime, lock, *args):     while True:         lock.acquire()         time.sleep(sleeptime)         lock.release()         time.sleep(sleeptime)  if __name__ == "__main__":     lock = thread.allocate_lock()     thread.start_new_thread(myfunction, ("Thread #: 1", 2, lock))     thread.start_new_thread(myfunction, ("Thread #: 2", 2, lock)) What is a smart pointer and when should I use one? When does reflow happen in a DOM environment? What kinds of activities will trigger reflow of web page with DOM?  It seems there are different points of view. According to ,  it happens   When you add or remove a DOM node. When you apply a style dynamically (such as element.style.width="10px"). When you retrieve a measurement that must be calculated, such as accessing offsetWidth, clientHeight, or any computed CSS value (via getComputedStyle() in DOM-compliant browsers or currentStyle in IE).   However, according to , taking measurement triggers reflow only when there is already reflow action queued.  Does anybody have any more ideas? Is a capacitor in an open circuit charged? Say I have a circuit consisting of a battery, a wire, an open switch, and a capacitor. The circuit is open since the switch is open.  My book says that the capacitor will only be charged when the switch is closed, but I don't see why this is true. I would expect the capacitor to be charged a little - not as much as if the circuit is closed, but still charged none the less.  To further illustrate my point consider this: If the circuit is open, the current must be zero. Consequently the field must be zero. For the field to be zero, the capacitor's field must cancel out the battery's field. Therefore the capacitor must be charged.  Generalizing this concept, shouldn't capacitors be charged (to a lesser degree) in open circuits?  EDIT: In other words, if the field is zero, the capacitor must be charged to cancel out the field of the battery. Joris and Srikant's exchange  got me wondering (again) if my internal explanations for the difference between confidence intervals and credible intervals were the correct ones.  How you would explain the difference? Apparent Violation of Newton's $3^{\text{rd}}$ Law and the Conservation of Momentum (and Angular Momentum) For a Pair of Charged Particles Consider a system of the two identical positive point charges situated in free space (isolated from the influence of any other external fields) as shown in the attached diagram. Particle $1$ is at $(a,a,0)$ and particle $2$ is at $(0,a,0)$. Their velocities, at the considered instant of time, are as shown in the diagram ($\mathbf{v}_1$ along the $+x$ axis, $\mathbf{v}_2$ along the $+z$ axis).    Now, by applying the Biot-Savart law, we find that the magnetic field due to particle $2$ at the position of particle $1$ is along $+y$ axis, which means that the force acting on particle $1$ is along $+z$ axis according to Fleming’s left-hand rule. A similar analysis shows that there is no magnetic force on particle $2$ as the magnetic field of particle $1$ should vanish at positions (relative to particle $1$) located along its velocity vector.  Now, if we observe the net torque on the system of two particles about the $y$ axis then it is non-zero and is directed along the $-y$ axis. Here, there are no external forces or torques acting on the isolated two-particle system, and yet the net torque, as well as the net force on the particles, are nonzero. Why? Also, Newton's third law of motion seems to be broken in this scenario. Why?    Edit $1$  I have come to know from the responses that the electromagnetic field itself takes away some momentum and angular momentum about the considered axis. However, I think that if I consider only two charged particles as my system then the Abraham-Lorentz force can be assumed to be acting upon the system, and that is sufficient to make sure that we have considered the momentum being carried away by the electromagnetic field itself.   Even after considering the action of the Abraham-Lorentz force for the two-particle system, the scenario breaks both Newton's third law and the conservation of linear and angular momentum. This is because the Abraham Lorentz forces do not exactly counterbalance the force and the torques, on the two-particle system under consideration, due to the magnetic field.    Edit $2$  The previous edit was a result of confusion and misunderstanding on my part. The force associated with the momentum carried away by the electromagnetic field as a result of the electromagnetic interaction described in the question is the Lorentz force itself which simply doesn't obey the third law of motion. The Abraham-Lorentz force is a different story. It is associated with the momentum carried away by the radiation emitted by the accelerated charged particles. This is an additional force apart from the Lorentz force and corresponds to an additional carriage of momentum by the electromagnetic field. The momentum carried away by the electromagnetic field in correspondence with the Lorentz force doesn't correspond to radiation. My motherboard currently supports both SATA II and III (3 Gb/s and 6Gb/s respectively), but after reading some online, it seems as though connecting a HDD to the 6 Gb/s is pretty much pointless. If this is the case I'm going to leave my two SATA III ports open for something that can actually use it (which at this point I'm not really sure what can).  This is part of an article I read:     In terms of everything else, we saw basically no difference from the same single drive being plugged into a SATA 6Gb/s or SATA 3Gb/s port. All of this is obviously due to the hard drive not being able to actually take advantage of the 6Gb/s bus.   from . It has come to the point in my computing program now where I have 5 swinging pendulums that are all modified at once by slider values. These values are drawn onto the from and passed through the class pendulum. To change the values the update button is run, and their is a default option to use a setup that works. The values are also shown on screen through some simple labels. The zero button sets all values (except length) to zero.  The values for each pendulum drawn is:   String length angle Acceleration (angular) Angluar velocity Damping or friction Gravity   My calcuations for these values: (Bob = the weight at the end of the string, and there are X and Y Co-ordiantes for it.  bobX = originX + (Math.Sin(angle) * length);         bobY = originY +(Math.Cos(angle) * length);   Caclulate Acceleration:  Angular Acceleration = (-1 * gravity / length) * Math.Sin(angle);    Increment Velocity:          Angular Velocity += Angluar Acceleration;   Increment Angle          angle += AngularVelocity;   Friction action, pendulum eventually 0's          AngularVelocity*= damping;   Now my next task is to make the pendulums collide "realistically" and recreate a newtons cradle type effect. I've looked into elastic collision solutions on particle e.g. here is an excellent example:    I've also looked at the raw physics behind it  but my brain couldn't get to grips with the raw physics side of things.  So I'm wondering if anybody could help me figuring out the theory for the collisions.  My current idea is when the co-ordinates meet the velocity will simply change polarity e.g. +10 to -10 in the opposing pendulum. Am I correct here?  If you are into code I've posted the code on stack overflow How to get Steam to recognize existing game files from a different source? Let's say I have a game bought on retail/other digital download and installed on my hard drive. I buy the same game (or a minor variant of it, say the GOTY edition) on Steam. It should be possible to use the existing installation to avoid the generally big downloads. This is very useful as it saves both bandwidth and time.   Previously, as far as I understood, Steam downloaded the game files directly to steam\steamapps\common\&lt;game_name&gt;. Since this folder would be created on starting the download, pausing and closing steam, copying the game files to this folder and then validating game files would make Steam absorb as much as possible and just download the missing files.  Currently, Steam downloads the files to steam\steamapps\downloading\&lt;game_id&gt; and then moves them over to the aforementioned folder once the download finishes. So first of all, what the final folder would be is not clear. So what would be the correct way of doing the same thing, that is, make steam use as much of the existing files as possible? Should the files be copied to downloading\*\, or should I figure out the actual folder (say via googling) and copy the files to steamapps\common\*\?  More specifically, I had a retail copy of Arkham City installed and I just bought the GOTY version on Steam. Now I tried both of the above things, in either case, the validating does not seem to do anything. Assuming I have the correct folder name steamapps\common\Batman Arkham City GOTY, according to , if I copy the files there, Steam seems to just continue with its 17GB download. If I copy it to steamapps\downloading\200260 then the download keeps stopping every few seconds with "Disk Write Error" after modifying 1 or 2 files, and I have to keep hitting resume. Show:$$\lim_{n\to\infty}\frac{\sqrt[n]{n!}}{n}= \frac{1}{e}$$  So I can expand the numerator by geometric mean. Letting $C_{n}=\left(\ln(a_{1})+...+\ln(a_{n})\right)/n$. Let the numerator be called $a_{n}$ and the denominator be $b_{n}$ Is there a way to use this statement so that I could force the original sequence into the form of $1/\left(1+\frac{1}{n}\right)^n$ Tikz: shading region bounded by several curves I know that my effort below can be improved upon considerably.  In particular, there must be a way of shading the region in a single scope, as opposed to subdividing as I have done (thus necessitating a hidden gray boundary).  Neither am I fond of sample points, but this is where my research has led me.  Your constructive criticism is appreciated.    \documentclass{article} \usepackage{tikz} \begin{document}  \begin{tikzpicture} %graph \draw[draw=gray!50!white,fill=gray!50!white]      plot[smooth,samples=100,domain=0:1] (\x,{0}) --      plot[smooth,samples=100,domain=1:0] (\x,{1}); \draw[fill=gray!50!white] plot[smooth,samples=100,domain=1:2.71828] (\x,{ln(\x)}) --      plot[smooth,samples=100,domain=2.71828:1] (\x,{1}); \draw[domain=0:4] plot (\x,{1}); \draw[samples=100,domain=.25:4] plot (\x,{ln(\x)}) node[above left]{$y=\ln x$}; %coordinate grid \draw (-.5,0)--(4.5,0) node[right]{$x$}; \draw (0,-1.5)--(0,2.5) node[above]{$y$}; \foreach \x in {1,2,3,4}     \draw (\x,2pt)--(\x,-2pt) node[below] {$\x$}; \foreach \y/\ytext in {1,2}     \draw (2pt,\y)--(-2pt,\y) node[left] {$\y$};     %labels  \node at (.75,.5) {$\mathcal{D}$}; \end{tikzpicture}  \end{document} If every polynomial of degree 2 is reducible then $K$ is algebraically closed? Photo Map tip in QGIS 3 on windows OrderBy and OrderByDescending are stable? Meaning of "over in" I read this sentence in a book:     I just took part in a study over in the Psychology Department.   Why do we add over in front of in the here? What is the difference between class and instance attributes? I`m using Firefox Sync on a bunch of computers.   I would like to manage my account, by removing some computers. I can't find the place to do this, it should be on the Firefox Sync page, but the official page only has the privacy and download information.