I want to protect my USB flash drive in general so these files and directories are readable but not copyable so no one can make a copy of these files in my USB flash drive.  Is that possible?
I have customers who want to buy large amount of flash memories but he wants to copyright all files inside it.   The flash will contain files that will be delivered for his customers but they're not allowed to copy or delete any of the files the only allowed permission is to ready the files.   I searched and found many solutions but all have on function it WriteProtect the USB though I can't add files to Drive at all but I can delete or copy any file in the drive.   Is there any way to protect the flash memory so I can't copy data out of it?
Using $g = \frac{Gm}{r^2}$, the force on a point mass located at 1 AU from the Sun ($m = 2 \cdot 10^{30} \text{ kg}$) is about ~0.006 N/kg.  Does that mean that, e.g., a 70 kg person is ~42g lighter during the day, and ~42g heavier at night? That seems like it could make a big difference for things like measuring gold bars or other weight-sensitive items. (Gold arbitrage: buy your gold during the day and sell it during the night! Risk-free profit!)  This makes me suspect that I'm overlooking something obvious, because a ~0.05% weight difference seems like something everyone would have noticed long ago. So what am I missing?    Edit: A few answers below indicate that there shouldn't be any weight difference, because the Earth orbits the Sun in free-fall. But if that's the reason, does that mean that a 1:1 tidally-locked Earth-Sun system wouldn't experience differential gravity from the Sun on opposite sides? That doesn't seem right. Polynomial irreducible - maximal ideal I have a couple of ideals which I wonder if I correctly classify as maximal/prime ideal.  $I_1 = \langle 2x^2 + 9x -3\rangle$, $I_2 = \langle x - 1\rangle$  $\mathbf 1)$ Is $I_1$ a maximal ideal in $\mathbb{Q}[x]$?  Yes, since $I_1$ is irreducible with $p=3$ using Eisenstein's criterion, thus maximal ideal.  $\mathbf 2)$ Is $I_2$ a prime ideal in $\mathbb{Q}[x]$?  Yes, since $I_2$ is obviously irreducible, and thus a maximal ideal, and every maximal ideal is a prime ideal.  $\mathbf 3)$ Is $I_2$ a maximal ideal in $\mathbb{Z}[x]$?  Yes, $I_2$ is obviously irreducible, and thus a maximal ideal.  $\mathbf{Edit:}$ No, as it is not a field. $$ $$  Am I right in my conclusions?  Appreciate any help. How can I disable the 2nd hard drive in my 27" iMac? For each $x,y,z∈\mathbb N$, if $x<y$ then $x+z<y+z$ This isn't a particularly major issue, but I've had this thing nagging me for a while. When looking at QGIS 3.4's global variables, user_full_name is assigned my given and surname, which includes a diaeresis (¨) somewhere in there. I can't seem to find any way to get QGIS to switch/adapt encoding and display the name correctly. The accented character gets switched to that ubiquitous black rhombus.  I looked for info on this behavior and found moderately similar issues like  and  but it's not exactly the same problem as it's not a geodata encoding issue but rather how QGIS deals with values pulled from the OS.  I have tried unchecking the Override system locale tickbox in Options|General as I prefer to use American English even though my OS is set to Canadian French. No effect to observe.  There's somewhat of a workaround right now which is to fix the name in the Project variable project_author as it is editable (it's filled with the offending global variable by default).  I'm curious to know, though, if someone has encountered this before and if there's a solution in QGIS. What is the closed form for $\sum_{n=1}^\infty \frac1n - \frac1{n+1/p}$? A while ago, I started to look at expressions of the following form: $$ S_p:=\sum_{n=1}^\infty \frac1n - \frac1{n+1/p}, $$  where $p$ is prime, because otherwise things get too complicated for me at the moment.  What I found so far is the following: $$ S_p= p -\log(2p) - \frac12 \pi \cot\left(\frac\pi p\right) + T_p, $$ where $T_p$ contains $\frac{p-1}2$ terms $t_{p,k}$ of the form:  \begin{cases} \pm 2 \sin\left(\frac{k\pi}{2p}\right) \log\left(\sin\left(\frac{k\pi}{2p}\right)\right) \\ \pm 2 \cos\left(\frac{k\pi}{2p}\right) \log\left(\sin\left(\frac{k\pi}{2p}\right)\right)\\ \pm 2 \sin\left(\frac{k\pi}{2p}\right) \log\left(\cos\left(\frac{k\pi}{2p}\right)\right)  \\ \pm 2 \cos\left(\frac{k\pi}{2p}\right) \log\left(\cos\left(\frac{k\pi}{2p}\right)\right)  \end{cases}   An example can be found .     How does the closed form for $\sum_{n=1}^\infty \frac1n - \frac1{a+n}$ look like? (EDIT: where $a=1/p$) How many ancestors alive 1000 years ago does a person have on average? I was thinking about something the other day (that is probably stupid), and thought this would be a good place to talk about it.  If someone wanted to draw its family tree over the last 1000 years, he'd write a binary tree with a depth of about 40 (counting 25 years on average between each generations). This tree would have 240 leaves, or about 1012 ancestors on the deeper level. That is obviously much more than the total world population and a stupid figure when you think about it.  The only explanation that I can think of is that a real genealogy tree must have "linked" branches at several levels that change the actual number of ancestors. Anyway, for an average person, how many ancestors would that make? Could one assume that all or nearly all of the persons that lived in its country or world region a 1000 years ago would be part of its ancestors? Not able to see links to chat, logout, or privileges At some point in (I think) the 90s, I saw an episode of something like Outer Limits or Twilight Zone where nobody was allowed to have more than average intelligence. Smarter children had to wear headsets which inhibited them from being too intelligent, administering minor electric shocks if intellectual thought was detected.  I can remember a final (or near final) scene of somebody watching his suicide and being upset but not remembering why because of the headset.  Can anybody identify the show and episode? Construct a fourth circle tangent to 3 circles forming a tangency chain Calculate the uncertainty in velocity of electron I got this question in one of my periodic test in coaching, I (seemingly) solved the question but later recognised what mess I did.  So, the question is :      Calculate the uncertainty in velocity of an electron. If the uncertainty in its position is ${10^ {-15}} \; \mathrm m$.   By simple calculations one can see that the answer would be ${5.79\times{10^{10}}} \; \mathrm{m/s}$. However, as one can see, the uncertainty in velocity is greater than the velocity of light then how is that possible or there is some other way to handle such problems.  P.S. I know the concept of dynamic mass but I am not very familiar with it. (I think that would work here, but don't know how?) My hypothesis is that $\mathbb{R \times R}$,  the set of all pairs $(r_1, r_2)$, of real numbers is uncountable. I understand that the set of all pairs of natural numbers is countable. But could someone explain why the set of all pairs of real numbers uncountable? I am having trouble proving it using diagolization How can $\pi$ be irrational if it can be calculated using an infinite series of rational numbers? Weird sharp vertices with subdivision modifier I have a simple skull model, to which I applied the subdivision modifier. For the most part everything works as expected, except I keep getting these weird sharp vertices and I can't seem to figure out how to flatten them.    I'm using Blender 2.8. Is this some kind of feature I can disable/enable for particular vertices? The distance between the sharp vertices and the gray outline differ.    Any suggestions please? Thank you!  EDIT: I also tried selecting as both - vertexes and edges and then applied Edge->Clear Sharp, but nothing changed. Memory Usage of SQL Server SQL Server instance on my server is using almost full memory available in my Physical Server. Say if i am having 8GB of RAM than SQL Server is using 7.8 GB of RAM from system. I also have read articles and also read many similar questions regarding same on this forum and i understand that memory is reserved and it is using memory.  But i have 2 same servers and 2 SQL Servers, why this is happening on a single SQL Instance not on other. Also when i run DBCC MemoryStatus than it is showing up...  VM Reserved 8282008 VM Committed 537936   so from this we know that SQL reserved whole 8GB memory, but why this VM Committed keeps increasing. What i understand is VM Committed is:      VM Committed: This value shows the overall amount of VAS that SQL Server has committed. VAS that is committed has been associated with physical memory.   So this is the memory SQL Server has committed (from this i understand that physical memory actually SQL Server is using at instance).  So like to know the reason behind this ever increasing VM Committed memory on my server and not on another. Thanks in Advance. How can I render an object with an hdr background? I have an object with an hdr for the background. What do I do in Cycles to render the background with my object?  How is this different from an ordinary render in Cycles?  The hdr is a big one, 350MB. I would like to know how to make this effect of merged circle selection. Here are images to illustrate:     Basically I'm looking for this effect:    How the merge effect of the circles can be achieved ? I didn't found any explanation concerning this effect. I know that to project those texture I can develop a decal system but I don't know how to create the merging effect.  If possible, I'm looking for purely shaders solution. A Basic Question about Gravity, Inertia or Momentum or something along those lines I'm trying to get through Spivak's Calculus on my own and even though I kinda understand induction I'm not so sure that's the case when it comes to complete induction. So I tried to do a starred problem which involves using it. But I'm not sure that my proof is valid, can someone check this for me?  So the problem is that I have to prove that     For every natural $n&gt;1$, if $n$ is not prime we can write it as a product of primes.   I'm starting with a base case. For $n=2$, $n$ is prime, so the assumption holds.  Let's assume that for some $n &gt; 1$ and also all numbers $p &lt;= n$ the assumption holds.  Then $n+1 = cd$. If $n+1$ is not prime, then $c &lt; n+1$ and $d &lt; n+1$, but as they are natural numbers, we can also write that $c &lt;= n$ and $d &lt;= n$. But we assumed that if $p &lt;= n$, and $p$ is not prime, we can write it as a product of primes. So if $c$ or $d$ are not primes, we can write them as a product of primes. That means that $n+1$ can be written as a product of primes if it's not prime, which completes the proof. The forgetful functor $\mathsf{Groups} \to \mathsf{Sets}$ admits a left adjoint, namely, "forming the free group" functor.  I was wondering if this has a left adjoint.  This seems unlikely, but I don't have a proof.  Is there a functor $\mathsf{Sets} \to \mathsf{Groups}$ that admits a left adjoint at all?