High CPU usage and load on simple tasks

Question: I know my dual-core AMD Athlon 64 X2 5200 is not powerful at all, but the problem is that I see how it is at (usually) 20% of usage in idle, and that's not a problem to me, maybe it just can't do much more... However, I note how sometimes it's "powerful", but sometimes no. I don't know if that's package-related, kernel-related, or some services... But the point is that it takes to 80/100% quickly for the most simple tasks I could do. Yes, it happens with Firefox obviously, but taking 50/60% when browsing throug my files isn't normal.
I have noted this behavior is not normal because I have seen how it can do much more in the past or in some rare occasions, so something makes me feel that there is an issue that cause my apps to use more cpu cycles than it should, all apps, nor only ... Or as if my graphics card were not used.
I have never tested Windows or other systems than MX Linux 19.2, so I can't test it in deep, however, I had the MX default Linux Kernel 4.19, and I note a very little difference (to better) when using current.
A process is ever consuming more CPU resources than usual is Xorg. I don't know if that's normal because it's persistent, always between 5% and 15%. But as I have a graphics card, I don't know why xorg needs that space or if it's affected/it affecs other processes.
I need to at that this sacrifice my CPU a lot because it's always overheating, so in the night this effect is a bit mitigated.
Is this maybe happening because of some kernel patches or wrong libreries configuration?
Please request whatever additional information you need.
System:    Host: <filter> Kernel: 5.6.0-1-amd64 x86_64 bits: 64 compiler: gcc v: 8.3.0
           parameters: BOOT_IMAGE=/boot/vmlinuz-5.6.0-1-amd64 root=UUID=<filter> ro splash
           acpi_enforce_resources=lax zswap.enabled=1 zswap.compressor=lz4 zswap.max_pool_percent=20 zswap.zpool=z3fold
           Desktop: Xfce 4.14.2 tk: Gtk 3.24.5 info: xfce4-panel, vala-panel, plank wm: xfwm4 dm: LightDM 1.26.0
           Distro: MX-19.2_x64 patito feo February 15  2020 base: Debian GNU/Linux 10 (buster)
Machine:   Type: Desktop Mobo: FOXCONN model: M61PMV v: FAB A1 serial: <filter> BIOS: Phoenix v: P02 date: 07/08/2008
CPU:       Topology: Dual Core model: AMD Athlon 64 X2 5200+ bits: 64 type: MCP arch: K8 rev.F+ family: F (15)
           model-id: 6B (107) stepping: 2 microcode: N/A L2 cache: 1024 KiB
           flags: lm nx pae sse sse2 sse3 svm bogomips: 10850
           Speed: 2700 MHz min/max: 1000/2700 MHz Core speeds (MHz): 1: 2700 2: 2700
           Vulnerabilities: Type: itlb_multihit status: Not affected
           Type: l1tf status: Not affected
           Type: mds status: Not affected
           Type: meltdown status: Not affected
           Type: spec_store_bypass status: Not affected
           Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer sanitization
           Type: spectre_v2 mitigation: Full AMD retpoline, STIBP: disabled, RSB filling
           Type: tsx_async_abort status: Not affected
Graphics:  Device-1: NVIDIA GK107 [GeForce GT 640] vendor: ASUSTeK driver: nvidia v: 418.152.00 bus ID: 02:00.0
           chip ID: 10de:0fc1
           Display: x11 server: X.Org 1.20.4 driver: nvidia unloaded: fbdev,modesetting,nouveau,vesa alternate: nv
           resolution: 1366x768~60Hz
           OpenGL: renderer: GeForce GT 640/PCIe/SSE2 v: 4.6.0 NVIDIA 418.152.00 direct render: Yes
Audio:     Device-1: NVIDIA MCP61 High Definition Audio vendor: Foxconn driver: snd_hda_intel v: kernel bus ID: 00:05.0
           chip ID: 10de:03f0
           Device-2: NVIDIA GK107 HDMI Audio vendor: ASUSTeK driver: snd_hda_intel v: kernel bus ID: 02:00.1
           chip ID: 10de:0e1b
           Device-3: Nam Tai E&E Products or OmniVision Sony Playstation Eye type: USB driver: ov534,snd-usb-audio
           bus ID: 1-2:2 chip ID: 1415:2000
           Sound Server: ALSA v: k5.6.0-1-amd64
Network:   Device-1: NVIDIA MCP61 Ethernet vendor: Foxconn type: network bridge driver: forcedeth v: kernel port: ec00
           bus ID: 00:07.0 chip ID: 10de:03ef
           IF: eth0 state: up speed: 100 Mbps duplex: full mac: <filter>
Drives:    Local Storage: total: 298.09 GiB used: 210.49 GiB (70.6%)
           ID-1: /dev/sda vendor: Hitachi model: HDS721032CLA362 size: 298.09 GiB block size: physical: 512 B logical: 512 B
           speed: 3.0 Gb/s rotation: 7200 rpm serial: <filter> rev: A3EA temp: 36 C scheme: GPT
Partition: ID-1: / raw size: 64.00 GiB size: 62.50 GiB (97.65%) used: 24.08 GiB (38.5%) fs: ext4 dev: /dev/sda3
           ID-2: /home raw size: 226.07 GiB size: 221.52 GiB (97.99%) used: 186.12 GiB (84.0%) fs: ext4 dev: /dev/sda4
           ID-3: swap-1 size: 1024.0 MiB used: 302.8 MiB (29.6%) fs: swap swappiness: 15 (default 60)
           cache pressure: 100 (default) dev: /dev/sda2
Sensors:   System Temperatures: cpu: 83.0 C mobo: 42.0 C gpu: nvidia temp: 45 C
           Fan Speeds (RPM): cpu: 0 fan-2: 0 fan-3: 2528 gpu: nvidia fan: 10%
           Voltages: 12v: N/A 5v: 2.93 3.3v: N/A vbat: 3.18
Repos:     Active apt repos in: /etc/apt/sources.list
           1: deb https://typora.io/linux ./
           Active apt repos in: /etc/apt/sources.list.d/debian.list
           1: deb http://deb.debian.org/debian/ buster main contrib non-free
           Active apt repos in: /etc/apt/sources.list.d/mx.list
           1: deb https://mirrors.evowise.com/mxlinux-packages/mx/repo/ buster non-free main
           Active apt repos in: /etc/apt/sources.list.d/sublime-text.list
           1: deb https://download.sublimetext.com/ apt/stable/
           Active apt repos in: /etc/apt/sources.list.d/wine.list
           1: deb https://dl.winehq.org/wine-builds/debian/ buster main
Info:      Processes: 229 Uptime: 6h 03m Memory: 3.85 GiB used: 2.22 GiB (57.7%) Init: SysVinit v: 2.93 runlevel: 5 default: 5
           Compilers: gcc: 8.3.0 alt: 8 clang: 7.0.1-8+deb10u2 Shell: quick-system-in running in: quick-system-in inxi: 3.0.36

Comment: Examples: Scrolling in Firefox sums around 30/40% usage, while a gif on the page could cause a 60/70% usage. With Firefox this problem is so hard.
Comment: Scrolling up and down in the whisker menu is also significative (+30/35%)
Answer: Maybe something is wrong with cooling of this CPU and it is speedsteping to some lower MHz than usual?
Comment: It's a good highlight and something I have not thought... Could you add ways to measure the CPU MHz in real-time and in that way possibly get conclusions? — In my attached details, it's shown that my CPU has `Speed: 2700 MHz min/max: 1000/2700 MHz Core speeds (MHz): 1: 2700 2: 2700` — Not evident thermal throttling here.
Comment: I'll let it stand for now, but yeah - this is closer to a comment than an answer.

High CPU usage and load on simple tasks


How to document business rules

Question: I am wondering what would be the formal and the most commonly practiced method of documenting business rules?  Also how do you document the UI specifications of development artifacts (e.g. Documenting form fields and how buttons behave on form, info text .. etc)
Comment: "Formal" is rarely the "best way" . Your title is confusing me :-P
Comment: I have changed it,  I hope that is less confusing :)
Comment: Technical doc or functional doc? Who is going to read this documentation?
Answer: Probably the most common form is Use Cases. You can supplement them with screen mock-ups and descriptions.
A book I'd recommend is "Writing Effective Use Cases" by Alistair Cockburn. It describes how you can write use cases at various levels of detail, how to avoid falling for the 'template' driven approach, and just sticking to documenting the necessary and relevant bits.
Answer: Documentation is often done in use cases and other prose forms. In addition it can be extremely useful to have UML diagrams and other graphical forms that give you an overview on a higher level and are easy to comprehend in a shorter time than reading pages and pages..
And last but not least the best documentation imho are test cases that execute the business rules. That way you can change the code and find out that you are violating a business rule. Otherwise the documentation is always under the danger of becoming stale and out of date.
Answer: Whatever method you use, be sure that they can be actively maintained. They should be living documents. Housing the documents in a Version Control system or some sort of document management system like Sharepoint, can go a long way towards keeping them maintained. Keeping track of business rules through word documents attached to emails is a horrible way to deal with the issue, since it leads to multiple versions floating around.
Answer: For business rules, I think @Joppe pointed to the diagram we all were thinking of.
Use Case Diagrams make for excellent overviews of what the system does and how (and how many) actors/roles interact with this system. For complex use cases, UML already considers notes and comments to complete the information, so go ahead with them too. Just a piece of advice, give a code to each Use Case (i.e. UC-1, UC-n) so you can make references to use cases from other documents, for example, the UI documentation.
For UI documentation, wireframes have become a common practice. Quite better than screen-shots because they look cleaner, they are also editable and generate assets you can version. Some tools make'em interactive too. To complete this "documentation", write a brief introduction of each view and describe every button or field involved and do references to the UC (code) involved.
Regarding the UI, document the navigation plan too. Navigation plans have no UML diagram but State Machine  Diagram can do the job.
Finally, as with any other documentation, keep in mind its audience

Technician: you can go deep into details and use a technical language
Not Technician: avoid technical language. Use the ubiquitous language of the domain (business)
Answer: I highly recommend to strictly separate the business rules from the system specification by only refering business rules from use case and UI design.
My favourite technique is:
- Have a list of identified business rules in a spreadsheet.
- In the system design, use case specification, user stories or whatever, just specify "The user enters information as specified in business rule BR012", "The system calculates the total amount as specified in business rule BR510".
I recommend this article http://www.allaboutrequirements.com/business-rules/
Comment: There are many rules you just cannot represent in a diagram! Keep to straightforward English ( or users language ) prose, and , possibly arithmetical formulas. Plus be sure to reference any standards, protocols  or regulations which the system has to comply with.
Answer: Try generating UML diagram using visual studio code and Plant UML plugin

How to document business rules


how do I set default permissions when copying a file from Windows -> OSX

Question: I am developing a ruby on rails app on OSX and I am logged in as an admin user.
On my Windows box I am creating my images, but every time I copy them to the OSX box, the permissions are weak (understandably I guess).
So per photo I keep having to right click, info and give everyone permissions to read and write, or my web server wont serve em up.
What is the easiest solution? an Applescript to auto give it full permission? is there a setting perhaps cause it's annoying to do it 25 times a day.
and yes I can use the shell with a chmod, but that's still annoying.
Answer: Each process on Unix-like systems has a field called "umask" that controls the default permissions. It's normally octal 0022, which means deny write permission to group and other. If you're using a Terminal window to copy over your files, try typing
umask 0000

beforehand. Alternatively, leave a Terminal window open with the following bash command running:
while true; do chmod 0666 *; sleep 1; done

Answer: If all of the images are going into the same directory, you could add an inheritable access control list (ACL) to the directory; then any files (i.e. the images) copied into it would get that ACL automatically.  Set this up with something like:
chmod +a "group:_www allow read,write,readattr,writeattr,file_inherit" /path/to/imagedir

Note that you may have to play around with the access to get the web server everything it needs.  e.g. if it needs to read/write extended attributes, delete files, etc you'll need to add the appropriate permissions to the ACL.  Similarly, if you need it to inherit to files added to subdirectories as well, you'll need to add more types of inheritance (and maybe recreate the subdirs so they pick up the change).  Also, I'm assuming this is the standard OS X 10.5 Apache install, running as the _www user, which is a member of the _www group; if not, adjust accordingly.  See the man page for chmod for details.
Answer: If you are copying many files/dirs, pack them in a zip in windows, and decompress it in mac. The files extracted will have proper permissions (at least, works with unarchiver)


Proof Techniques to Prove System Secure

Question: I have so far seen the proof by reduction technique to prove the security guarantee of cryptosystem where we consider breaking the cryptosystem as hard as solving a difficult mathematical problem. What are the other proof techniques used to prove the security of the Cryptosystem? It would be beneficial if the technique is briefly stated.
Answer: The question mentions proof by reduction to a difficult mathematical problem (e.g. Computational Diffie–Hellman). That's not the only common use of proof by reduction to prove the security of a cryptosystem: instead of hardness of a math problem, we often assume existence of a cryptographic building block with some assumed cryptographic property, like a block cipher computationally undistinguishable from a random permutation when the key is random, or a hash assumed to be accessible to adversaries only as a random oracle.
For some systems we have direct proof of perfect security by an information-theoretic argument, e.g. establishing that no information about plaintext can be gained from ciphertext in the One Time Pad. Problem is, the systems which security is provable by that line of proof all need a secret key as large as the whole plaintext ever transmitted (demonstrably if plaintext is assumed random), and thus are impractical. In particular, none can be a secure cipher, by the mathematical definition of that. So for proof of practical cryptosystems, the information-theoretic line of argument must be used in combination with proof by reduction and assuming something.
I  know no other mathematical security proof method for cryptosystems. I know no practical cryptosystem with a full mathematical proof of security. And even if we cut corners on practicality, existence of a secure cipher would imply P≠NP, and we are not there.

However we also have arguments of security. We can design a cryptosystem or building block (such as a block cipher or hash) with parameters (in particular, number of rounds and width of variables), examine how difficulty of breaking it by known cryptanalytic methods become harder when these parameters grow, and convince ourselves that this trend will go on (this is the hardest and most uncertain); then conclude that with certain large-enough parameters we are safe from these known attacks.
With the rare exception of the One Time Pad, perhaps coupled with Quantum Key Distribution, all deployed cryptographic systems that it's reasonable to trust use this later line of argumentation.

Proof Techniques to Prove System Secure


OpenJump LoCoH Analysis Output?

Question: I really need some help!  I am doing a k-LoCoH analysis in OpenJump.  The analysis is working, but I'm having trouble understanding the output.  There is a "density" column in the output, and I'm not sure what units this is in, or what it indicates.  I know by highlighting some of the polygons that the higher the number in the density column the more used the area...but I still would like to know what this number actually means before I continue with my results! Please help!!
Comment: What is "k-LoCoH analysis"? Is there some plugin for that?
Comment: k-LoCoH is part of the HoRAE (Home Range Analysis and Estimation) toolbox for OpenJump.  It's super useful - however I really need help understanding what the "density" signifies in the attribute table...
Answer: The OpenJUMP HoRAE download http://www.geo.uzh.ch/~sstein/ojhorae/openjump171plus_moveantools_oct2014.zip comes with manual "horae_documentation_v1.2final.pdf". The description of the KDE method on page 17:

In general the KDE method will return a raster with each grid cell
  containing a "density" value, and not home range polygons. To derive
  the home range polygons a contouring algorithm needs to be applied.
  Assuming that density can be related to probability it can be said
  that a grid cell (i.e. location) with some density value reflects a
  probability that the animal can be found in that cell. If the value of
  a cell is zero, the animal is unlikely to be found there. Hence, if we
  want the area that has a 95% probability of encountering the animal
  within, we will calculate a contour line that encloses 95% of the
  density of all cells (volume).

I have no experience about KDE but it seems to me that the unit of density is related to probability but the scale is not fixed. The upper limit of scale may be different for individual source data set and for analysis made with different parameters. Density value of 0 means always that it is unlikely to meet animals in that cell but density value of 100 does not tell anything as is but you must make statistical analysis first to reveal where value 100 stands in the probability curve.
Be careful with my answer because I know nothing about home range analysis and KDE method. Fortunately it is easy to find good reading because the author, Stefan Steiniger, is listing eight scientific literature references about the KDE method tens more about HoRAE in general in the HoRAE manual.
Comment: Thanks for your response - but I am not running a KDE analysis, I am doing a LoCoH.  I have read the manual, and there is no information about the attribute table LoCoH produces.  Also, the ranges of values within the density column is from a 3 digit number to a 7 digit number, leading me to believe that it is not a probability.  Any help on reading the attribute table for LoCoH is greatly appreciated!!!
Comment: I would try to find a library which has an article by Getz and Wilmers (2004) and the refined one by Getz et al. (2007) and check what they say about the method. I believe also that Stefan Steiniger is following OpenJUMP users and developers mailing lists.
Answer: It should be a simple count of the number of convex hulls/observation points that the cell is related to. So, if the count number is higher its more likely that the animal can be found in the cell.

OpenJump LoCoH Analysis Output?


How to use lockdep feature in linux kernel for deadlock detection

Question: I have a linux kernel driver and a user app that interacts with it. The kernel driver has a deadlock in it. I came accross this feature in the linux kernel called "lockdep". I was able to configure it and recompile my kernel (and I do see the lockdep folders in /proc). But I don't know how to infer the output of this tool or how to go about debugging the driver using this tool for that matter. Any help will much appreciated.
Thanks!
Answer: To enable lockdep feature, edit .config file through menuconfig:
make menuconfig

And enable following in Hacking Options:
 1. [*] Detect Hard and Soft Lockups
 2. [*] Detect Hung Tasks
 3. [*] RT Mutex debugging, deadlock detection
 4. -*- Spinlock and rw-lock debugging: basic checks
 5. -*- Mutex debugging: basic checks
 6. -*- Lock debugging: detect incorrect freeing of live locks
 7. [*] Lock debugging: prove locking correctness
 8. [*] Lock usage statistics

Recompile the kernel:
make ARCH=i386 -j4 //whatever your arch is

Now, boot the new kernel image, under /proc you should see the following new folders:
/proc/lockdep
/proc/lockdep_chains
/proc/lockdep_stat
/proc/locks
/proc/lock_stats

Now, insert the module you think that is causing the error, and access it with your user application (or whatever way you use to run your driver module). If the app deadlocks(hangs), do a:
ps -aux | grep <app_name>

you should see a +D (uninterruptible sleep) state for your app, do a:
dmesg

The log it prints will include the function/file causing the deadlock.
That's it!
Comment: I have enabled those options. But the dmesg does not report deadlock and I find that `debug_locks` is zero in the file `/proc/lockdep_stats`. I do not know the reason.
Answer: There is not much to it – the lockdep code will simply print a description of the situation and a stack backtrace to the kernel log when it encounters a locking sequence that potentially deadlocks. You just have to watch your kernel output (via dmesg or serial line or whatever you use).
The lockdep code debugs only locks, it can not warn you about deadlocks that arise from something else.
Comment: If I don't see any deadlock (arising due to locks) related message in dmesg, can I conclude there's no deadlock in my code? Does lockdep detect *every* deadlock?
Comment: @brokenfoot No, not really. You have to exercise all the code paths leading to a lock/unlock/sleep/whatever operation. What lockdep does is to record information like "lock A was taken before lock B" and it complains if it ever encounters two situations where two locks were taken in opposite order. (Here "lock" refers to "lock classes", so a lock inside a struct counts as one lock even for two different objects.)


suddenly no service, except ssh is accessible from wan

Question: I recently did install the GNOME Desktop and Graphical Administration Tools package groups to my remote host, for remote desktop connection. After the installation of nearly 550 dependencies was done, I could not connect to my personal website which is also hosted on that server.
Interesting stuff is, that I have no log entry in the access log of the web server, even though the web server (nginx) is running.
After being shocked by the results of my update, I checked other ports too, but I can't access on any port, but 22.
I did almost exactly the same as described in this tutorial about setting up the gnome gui on centos 7.
Since i have no entry in /var/log/nginx/access.log neither in /var/log/messages which would explain this behaviour, i have no idea where to start to fix.
Did anyone have a similar issue? Where should I start to fix the problem?
Answer: Sounds like a firewall issue. Try using nmap from another machine on the same network to see what ports are open. If no other machine is available to you, perhaps you can ask support for the hosting service to do this for you. If you are still able to log into the machine, then as root, use netstat -al to see what ports are listening. Use iptables -L or firewall-cmd to see what firewall rules are in place.


Novel with societal breakdown and spaceship passengers marooned on a planet covered with a city

Question: I read this novel when I was young. It involved some sort of societal breakdown (I think) and ended with the passengers of a spaceship marooned on a planet covered by a single abandoned city. Some of the passengers were reptilian species but the main characters were human. It could be from 1950 - 1960.
Comment: Sounds like it could be Turtledove's alternate WW2 series in which there was an alien invasion by lizard people. A later book in the series has them visiting the alien homeworld.
Comment: possibly the same as https://scifi.stackexchange.com/questions/167978/series-of-novels-involving-a-galactic-empire-in-slow-decline
Answer: Sounds more like "Star Rangers"
A ship of the Star Rangers of the collapsing Galactic Empire flees from the ships of one of the fleets forming out of the remains of the empire's fleet.  The Star Rangers are still loyal to the Empire and Central Control, but hated and hunted by the troops of the new empires.
The ship leaves the normal flight paths to escape, and lands on an unknown planet.
There are ruins all over the planet.
Among the Star Rangers are humans and at least one alien that could be described as reptilian.
They find a bunch of other refugees in one of the cities, and join up with them.
Eventually they discover that the "unknown" planet is in fact the Earth, and that city they are in is where the ships were launched that founded the Empire.
There are still humans on the Earth, but they are primitive - they rejected technology and went back to nature.  They aren't immune to some virus or other disease the refugees from the Empire have - some of the natives die.  I think there was also a native disease that also killed some real jerk among the refugees - it's been a long time since I read it, though, so I may have that mixed up with another story.
Answer: Andre Norton's Galactic Derelict comes to mind:

There's societal breakdown on the scale of a galactic civilisation.
The protagonists arrive on an alien world covered by a vast, ruined, city in a somewhat stolen space craft.
The main protagonists are human but the main other species they interact with are somewhat reptilian.
It was first published in 1959.

However the reptilian species appears to be native to the city world rather coming with the human protagonists by star ship at the time of their arrival.
Comment: Nope.  No aliens in "Galactic Derelict."  They didn't steal a ship, it was abandoned 10000 years ago on the Earth.
Comment: @JRE There are several alien species in _Galactic Derelict_ at least two of whom are intelligent. They did kind of steal the ship, the crew were already dead but it wasn't their ship to use.


SPF Record for Google Domains Email Forwarding

Question: I've got a domain setup with Google Domains.  I'm using CloudFlare for the name servers and I have the correct MX records setup (https://support.google.com/domains/answer/9428703) to point back to Google Domains so that I can use their email forwarding feature (all email from the various addresses gets forwarded to various Gmail accounts).  I'm now trying to figure out what SPF record I should create to prevent email spoofing.  So far I haven't been able to find any concrete details on this.  I also wouldn't mind figuring out if it's possible to create records related to DKIM and DMARC.
Comment: Your email provider should tell you what to put as SPF/DKIM/DMARC since what you put there is hugely dependent on its own configuration. Other than that they are all handled through DNS `TXT` records, so if your DNS provider allows `TXT` records, you can technically enter any SPF/DKIM/DMARC information you need.
Comment: My email provider would be Gmail but I use Google Domains to forward emails addressed to my domain to Gmail addresses.  Gmail has it's own SPF/DKIM/DMARC configuration but that's obviously for @gmail.com accounts.  What I'm trying to figure out is what I need to enter for the various records since I'm using Gmail but my own domain via forwarders.
Comment: Did you ever find a solution for this?
Comment: The SPF answer below works great, but I'm also still looking for working DKIM and DMARC configuration for Google Domains Email Forwarding.
Answer: My understanding is that SPF is for remote servers to authenticate the sender of messages from your domain.  Therefore, the SPF record should indicate your sending systems and does not worry about inbound servers.  For messages from remote domains, they would have to add the Google Domains forwarding servers to their SPF record, which they clearly would not do.  Therefore, as far as I can tell, messages from a random domain and forwarded by Google Domains email forwarding will always fail SPF checks at the address you forwarded the mail to.
In my case, I was getting SOFTFAIL errors on messages forwarded by Google Domains.  If the remote domain published a FAIL policy by using -all then I imagine I would be losing messages.
I would recommend looking at Cloudflare's email forwarding, since you are already using them.  Their email forwarding service properly adjusts incoming messages so your SPF checks for mail you receive will be appropriately evaluated.
Answer: If you are using gsuite, your SPF record should be v=spf1 include:_spf.google.com ~all perhaps that will work since it is google generic SPF by the look of it.
https://support.google.com/a/answer/33786?hl=en


Strength For Dowels

Question: This wouldn't really be a woodworking question but I need to know for future reference. I'm doing a school project where my team and I are making a car out of cardboard, glue and two 3/4in x 40in dowels. So I would just like to know the strength of the dowels because they would most likely be used as the axles of the car (Where the wheels attach). Our "Driver" per se, weighs about 120 pounds so he's a skinny guy, but I just want to know if they have they strength to support his weight. The pressure would be mostly situated on the middle of the dowel so that is where my concern stems from. If anyone who knows what they're doing then that would be a big help because I know nothing of this.
Thank you for your help!
Comment: Yeah, this is probably off-topic. But you should remember that engineering is a combination of research and analysis, and iterative experimentation. You should dream up some tests to see how your materials deform under static and dynamic loads. You probably need to come up with an idea of a safe margin as well. Like, don't design for 120lbs but rather some value above that.
Comment: A rough approximation via The Sagulator (using 40" length, 1.5" depth, 0.75" thickness, 120 lbs center load, floating, Oak, Southern Red) gives a 6" deflection. That agrees with my gut reaction that 3/4" dowel are way to skinny for supporting a 120 lbs person.
Answer: The centre of the axle is the worst place a point load. The best place to apply it is just inside the 2 wheels. If the structure can't transfer the driver's weight out to those points, then build a truss unit that rests on top of the axle to help distribute the load without too much flex. You can also build a box beam or a triangle beam, much like a tower crane.
If the driver is the only major load, try to have the weight shared evenly by both axles.

Strength For Dowels


How can I help my adult rabbit gain weight?

Question: I have a female English Lop that started growing well and was on a healthy track to meet normal weight requirements.  She got stressed out and stopped eating and drinking.  We were able to prevent total GI statis with yogurt and got her eating again.  But her growth has stopped.  Normal weight for a Adult Female English lop is 10.5 pounds but she has stalled around 9 pounds since she was 7 months and is now approaching 12 months.
We free feed(as much as she wants) 16%-18% Professional Show Rabbit feed currently.  We provide her hay but have limited it because she will eat only hay and avoid pellets if we let her.  We also try to supplement with fresh parsley every other week.
There are no real signs of any health issue.  She eats and drinks enough to maintain her weight.  Her droppings and urine appear normal and of appropriate quantity.  She has not had any mucus discharge, and our regular Physical examination shows no areas of concern.  Her weight is not unhealthy, though it she is not a full and meaty as she was at 6 months, she is still nicely proportioned.
Is there anything safe and natural we can do to encourage her growth?
Comment: Have you tried beet pulp? [Beet pulp is often referred to as a "super fiber" due to its high digestibility and ease of fermentation](http://www.triplecrownfeed.com/articles/beetpulphorsefeed-what-beet-pulp-horse-feed/#sthash.ijgBSbIL.dpuf)
Comment: No but I think i will.
Answer: There are a few things to help your bun gain a bit of weight.
In terms of hay, look to add some small quantities of alfalfa to the diet. Don't replace the timothy hay, but supplement in the alfalfa, perhaps about 25-30% ratio. This type of hay is good for young and growing rabbits and so will help her add on some weight as it is loaded with protein. You can also supplement in alfalfa pellets if you're feeding her pellets. Again, same reason.
For other foods you can try to include high fat/starch options such as oats, nuts, or barley. Keep it at really small amounts, like 1/4 cup, total daily. Perhaps introduce in smaller amounts at first. Also, treat foods such as raisins (not a lot, but they love them), berries (e.g. strawberries), apple, pear, basically the high sugar options.
As with all of the above, once she gains the weight, you'll want to trim back to eliminate some of this. Mostly, you'll want to get the alfalfa back out of her diet for the long term health. Bear in mind, too, that the health episode may have permanently stunted some growth depending on when. In that event, she may have peaked out on the weight.
Finally, when adding all of this into her diet, very carefully monitor her for any signs of illness or lethargy as well as keep an eye on her stools. Anything changes, stop the food supplement and bring her to a vet.
Comment: I would add [Critical Care](http://www.oxbowanimalhealth.com/vets/products/critical_care) and Pumpkin (NOT Pumpkin Pie Filling) to this answer. And a link in High Sugar options to http://www.rabbit.org/journal/3-3/digestibility.html
Answer: John Cavan has some reasonable and appropriate methods for increasing a rabbits weight in his answer. These should as he points out be used with careful monitoring, because high value foods can ultimately be harmful to your rabbit. The House Rabbit Society has some good diet recommendations.  Rabbits are somewhat dependent on having a high volume low value food supply for optimal health so dietary change to attempting weigh gain should only be considered when medically necessary, include  Critical Care and canned pumpkin (NOT Pumpkin Pie Filling) to John's answer when medically necessary.
You mention in your comments that your rabbit is validated to be in good health and the rationale for the weigh gain is cosmetic, to meet arbitrary requirements to gain recognition in competition.  Assuming the the 9 pounds of current weight give your rabbit a healthy exam rating, then it is difficult to imagine that increasing that weight by a third will be healthy.
Rabbits suffer health risks from increased weight (fat) the same as humans. Assuming that your rabbit's health and well being are your primary concern, and that showing her at her best is an attribute of that.  Let her health and not her weight be your guide.
You mention providing fresh parsley every other week, it is unclear if this is special treat or an attempt to provide fiber and/greens.  The current recommendations call for daily servings of fresh leafy greens.

Do not limit the amount of hay available to your rabbit. Serious life threatening conditions like wool block can occur in the absence of sufficient fiber. I do not believe there are any reliable references that recommend restricting hay (or alfalfa if appropriate) at anytime.
Increase your rabbits exercise opportunities.  Assuming that your rabbit has a frame larger enough to weigh 12 pounds, adding muscle would be the optimal form to add it in. Exercise will increase both your rabbits physical and mental well being. It may or may not increase her weight by a third, but it will increase her quality of life.

In summary to your question

"Is there anything safe and natural we can do to encourage her growth?"

Yes, give her a healthy diet consisting of unlimited hay, daily fresh leafy greens, pellets in moderation, and treats only occasionally. Provide her with at least twice daily opportunities for exercise, with sufficient area to jump, play and run.
Edit Expanding options
Due to a recent illness in one of our rabbits high nutritional values foods became a necessity.  Keeping in mind that you do need to be careful when changing a rabbits diet are are some foods that we used, they were all recommended by rabbit recovery specialists.

Canned pumpkin (NOT Pumpkin Pie Filling)
Rolled Oats, (Oatmeal that is not instant, feed dry and uncooked)
Sports hydration drinks (Gatorade, or similar with electrolytes)
Platinum Performance® Equine (mix with other foods)
Critical Care® herbivores  (mix with water or other foods)
Beet Pulp (feed wet or dry)
Answer: You can try Rabbit Mash
My senior rabbit has problems to hold her weight, so I explored this on kaninchenwiese.de.
It works for rabbits that need more energy because they are:

outside in the winter (low temperatures, beneath 0°C);
(chronically) ill;
seniors;
lactating or pregnant rabbits;
big breeds.

But one must be aware, that in the long turn, health issues could arise. If the rabbit eats the mash only, for example the food-grinding would be missed, which causes the teeth growing longer than usual.
And it should (even if you want the rabbit to gain the weight) feed in low doses. Around 1 full tea-spoon for one kilogram of rabbit's body mass daily is enough. (This would be 2 full teaspoons for a 2 kg dwarf rabbit per day.)
Possible ingredients:

oil seeds (sunflower, chia seeds, sorghum bicolor, hemp seed, pumpkin seeds, flax seed, poppy seed, sesame) they support the digestive system and help with fur issues;
flour seeds (amaranth, buckwheat, spelt seeds, barley seeds, grass seeds, oats, sorghum, corn/maize, quinoa) in general grains need to be fed with spelt to be healthy;
aromatic seeds (aniseed, nettle seeds, dill seeds, fennel seed, coriander, caraway, milk thistle seeds) they have a lots of positive active components;
bran a common food for horses;
dried herbs (examples: basil, dill, thyme, sage, chives, oregano, marjoram, parsley, camomile, coriander, rosemary, peppermint) ready mixes for rabbits, or self made mixes for special purposes, like supporting the digestive system or the breathing;
immune supporting additives, like drops/powder from the shop or ginger (ginger needs slow, slow, slow habituation, but has a positive effect to the immune system proven by research);
fruits (all by rabbits loved kinds, grated) mine love apple and carrot, raisins sometimes.

Example for a recipe from the linked website (above):

one cup crashed oat (with spelt);
one cup crashed flax seeds;
4 cups herb-mix.

My mix for my senior rabbit with chronically common cold:

1/2 cup flax seed;
1/2 cup sesame seed;
1/2 cup oat flakes;
1/2 cup sunflower seeds (without spelt);
4 cups of dried kitchen herbs (basil, thyme, marjoram, parsley, chive and dill);
Sometimes I grind 1/8 apple or carrot into the mix, or cut 4 raisins into very small pieces, to enrich the taste.

I use to buy this in a supermarket, because I am limited in my options to buy other seeds and dried herbs where I live.
Preparation
I use to mix the whole cups (without fresh food like apple/carrot) together into a closable box made out of plastic. Each day, I take two teaspoons full of the mix out of it. Then I crush the mix in a mortar, while waiting for the water to boil. I mix the crushed components with warm water (between 30 and 50°C) and let them swelling for around 30 minutes. The first times I need to try and estimate how much water is needed. One can use a little bit first and then add some until the consistency is like baby-food.
I serve this mix on a small plate to my senior, but in extreme cases it is possible to feed it with a syringe, too. If you have rabbits, who should not gain weight with your rabbit to coddle up, then you may need to separate them for around one hour. My senior defends her plate against her husband, so I do not need this. But maybe your rabbit is not powerful enough to do so.


What's the efficient technique to implement multilingual in ASP.net MVC

Question: What's the efficient technique to implement multilingual in ASP.net MVC?
Comment: This question is too broad... you're asking how to do i18n with ASP/C#, and there are quite a number of ways to do this, each of which may or may not be suited for what you want. You've also provided little to no other detail on how, specifically, you want this to work or what type of application you're building this for, so we can't tailor your answer to your specific needs, which only adds to my original point that this question **is too broad.** Did you try googling "ASP MVC Internationalization" or similar keywords to find what you're looking for?
Comment: I know there are a number of ways to implement multilingual but I want to hear from expert which one is the best.
Comment: possible duplicate of [Multiple languages in an ASP.NET MVC application?](http://stackoverflow.com/questions/4034/multiple-languages-in-an-asp-net-mvc-application)
Answer: I would use a Resource file. Extension .resx
Example have English.resx for english and Spanish.resx for spanish and have a way to store the local of the user and when the app loads you load the appropriate resx file.
In those files you coule use the , where the key would be the same in all the files and value would be sentence/word in that language for that key.
The keys would be used in your app in place of typing text straight into a text available tag.
Answer: Scott Hanselman wrote a good article covering this subject... Check it out here: http://www.hanselman.com/blog/GlobalizationInternationalizationAndLocalizationInASPNETMVC3JavaScriptAndJQueryPart1.aspx
Answer: Have you searched before you ask you question ?
there are many resources out there, have a look at the following links :
Multiple languages in an ASP.NET MVC application?
Creating ASP.NET MVC Multilingual Web Application
Multilingual ASP.NET MVC website
hope this help.
Comment: Thank you sir. these tutorials are great.
Comment: *StackOverflow: Replacing Google for lazy developers since 2008.*


Some js doesn't work as they should when I have cloudflare on

Question: I'm using magento 2.0.7, and I know is not a magento issue, but when I turn cloudflare on, some of the js doesn't well as they should, for example in the backend I can't save any product, and in frontend, the cart doesn't display the items.
Answer: Please disable the following in the CloudFlare dashboard:

Disable JS minification
Disable RocketLoader
Disable Mirage

That should solve the issues, if it doesn't please do come back on here.
Make sure your site is SSL throughout to receive the performance benefits of HTTP/2 through CloudFlare. You can do this by adding a CloudFlare Page Rule.
Answer: Check to see if you have Minify HTML on. If you do, the way that the Knockout JS uses comments to add DOM control gets stripped out and none of the back end grids will load as well as other seemingly random JS issues.
https://github.com/magento/magento2/issues/2697


Do we push for consolidating questions?

Question: Lots of simialr questions around skill challenges, and most of them are having some great answers. But I feel we're into a cascade where they feed off each other. What is the best way to handle this? Does it need some skillful moderator editing? Is this when we move to communitywiki?
Answer: No, not community wiki.  The answer is to close the ones that are duplicates, but I'm not sure we have that yet ...

What makes a skill challenge great?

This is about what features a great skill challenge has, not necessarily how to make them great.

How do you involve all players in a skill challenge?

How to craft and execute a challenge that will involve all your players at the table.

How to make skill checks more then just sequences of die chucking

How to involve good role-playing and story development in your skill challenge.

Need skill challenge ideas for Nature

Specific list of ideas for a specific type of challenge.

I don't see those as being duplicates, and I'm not sure their answers will merge well.
Comment: @Jeremiah There is a reason the close reason is `Exact duplicate`
Comment: I felt the first three are basically variants, that boil down to "How do I do a good skill challenge that gets my players involved" And the answers seem very similar as a result.
Comment: I don't see those as duplicates or sensibly mergable. And, D&D4 is a popular system, and Skill Challenges are poorly-understood and easily-done-badly enough that it's inevitable that there will be a lot of nuanced questions about them. I think that a clearinghouse of working wisdom on all facets of such a thing is a valuable outcome of the SE process.
Comment: I think when you see a set of questions like that, it's a great hint that a coherent, thorough investigation of the topic is possible. Sadly, there's no "coherent, thorough investigation of a topic" mechanism on this site. But if someone were to consolidate the information in the answers to those questions and create a "Awesome Skill-Challenge How-To", I think that would be a useful document to link to as a see-also.
Answer: Don't even try to merge questions.  Sure there's going to be a lot of questions that are extremely similar, but there's a specific element of the question that makes it unique.  There's a very good reason that there's the "Related Questions" part of the column to the right.  And if anybody comments or answers with a link to the similar questions, they will show up as "Linked Questions" above the related ones. So if you come across one question (say to skill challenges) that seems close to what you're looking for, but not quite, then most likely the other questions will appear as links from said question.
As C. Ross commented on his answer, there's good reasoning behind the wording of "Exact duplicate" for closing a question.
Answer: Close 'em as a duplicate and link them over to the one that's substantially the same.  Splitting basically identical responses across questions damages the ability to winnow via voting and encourages pointless duplication.
Comment: I have to admit I like the effect of merging questions more than I like the effect of closing one of a similar set.

Do we push for consolidating questions?


Negotiating after disclosing Salary Expected

Question: i am likely to get a job offer with a company for which i am very excited but i did a mistake by disclosing my salary expectation in start itself. After checking the current market trend and another job offer which i have, i feel that i asked for less initially whereas at my experience i can get a better salary. Also the company would easily be having a bigger salary range for that job profile. Please suggest how can i talk to HR for a higher salary and on what points should i negotiate.
Comment: Voting to close as off topic - "Questions should get answers explaining why and how to make a decision, not advice on what to do"
Comment: If you said what you're willing to work for, they're unlikely to go much, if at all, over that. The environment is _always_ changing, though, so chading after the best possible offer can mean never actually accepting a job; at some point you have to be willing to say "good enough". Unless you're something special, you need ghem more than they need you...
Comment: "disclosing my salary expectation" - in what form or manner did you do this? Also, although you have a basis for expecting more, do you have a basis for needing more? And when did you make the disclosure - before the other job offer or after? And has your current company made any attempts to keep you with additional compensation? You've left a lot to our imaginations...
Answer: You don't have job offer so right now so you don't have a salary to negotiate.
When you get an offer it will either be acceptable or not. If not make a counter.
You are not really in a position to argue your worth in the market.  They know what they pay their people.  They know the market. Don't lecture them on the market.
If they are low balling you they may accept your counter.
A good company will have a pretty tight pay range.  If you perform and move up and then your pay increases.  If you like the company and the offer exceeds or meets your initial expectation then just consider going with it.
Comment: Negotiations begin *far* before offers are formally extended.
Comment: @djechlin No kidding, "mistake by disclosing my salary expectation"
Answer: Asking for a higher salary after the job offer, could easily get your job offer taken back. Because usually several people are involved in the calculations and you already gave them a rough price. Unless you have some special skills then you're easily replaceable.
However you don't need to accept a job offer, you can negotiate when you have one, saying you'd love to work for them, but not for the same pay you were getting elsewhere, explain the market rate etc,. and see which way it goes. There is still leeway for negotiation.
Comment: Asking for a higher salary before getting the job offer could lead to not getting an offer, yet we still do it.
Comment: yes, that's why I left it out, because in my experience it's an automatic disqualification from giving them a job offer at all. It looks like they're either overly mercenary, or badly prepared, neither of which are desirable traits all else being equal.
Answer: As always in a negotiation, it helps if you have arguments backing your demands.
If you have another job offer, you can safely try raising your salary.
Explain them:

The initial position (or how you understood it) is different from what you now know it actually is: after talking with them, you learned new information about the job and want to be paid accordingly.
Salary is just 1 item in a benefits package: if they have a lot of other benefits (pension funds, paid vacation days, company car, insurance, phone, laptop, ...), the salary can be lower, if they don't, the salary will be higher. It's the total package that counts.
You have another job offer in the range of XXX-YYY, which corresponds with what you believe you are worth.
You did your research on the job market (glassdoor.com, other collegues in the domain) and know the salary ranges are XXX-YYY.

If they challenge you that you asked for less before, remain calm, polite and friendly, but explain that you are convinced you are worth the salary you are asking for, and that you can deliver a lot of value to their company - and believe you should be compensated accordingly.


No power in a fluorescent tube lamp

Question: I wanted to use an oldish fluorescent tube lamp and find there is no power, I replaced the tube, also the stater, also the fuse in the plug and still no power. I have a multimeter but don't know how to use it ( 87 yr old widow), any advice?
Comment: Hello, and welcome to Home Improvement. I'm afraid we're unlikely to be able to help you fix this; you'll probably have to get someone to fix it. But, if you're in a fix, adding pictures of the lamp, starter and fuse would help. And, you should probably [take our tour](//diy.stackexchange.com/tour) so you'll know how best to participate here.
Answer: There is one part you haven't tried, and that is the "ballast".   Fluorescent lights aren't like incandescent lights, they can't be connected directly to mains power.  They need a device to limit how much electric current they draw, and that device is the ballast.
Ballast failures on older lamps are very common.   If you want to replace  the ballast, you can get a modern electronic one that will perform much better.  However the wiring will be different, so you may need to rearrange some wires.  Follow the instructions of the ballast faithfully, don't wire it wrong simply because the ballast is already wired a particular way.
Another option is to convert to LED lighting.  In this case the ballast is removed entirely and mains power is sent direct to the LED light (through the switch). They make LED light "tubes" that take mains voltage and fit where the tubes go.   Beware of "plug-and-play" LEDs that require a working ballast to be there.

No power in a fluorescent tube lamp


Creating nice curves with InDesign

Question: I am trying to create nice looking curves with InDesign, but I can't get a good result using the Pen tool.
What I want is something like the curves in the following pictures on top and below the title text:
Answer: I'd hazard a guess that in 99.5% of uses such as this those flourishes are not drawn or created.
Rather they are decorative glyphs found in any number of fonts.
Here's one such font: http://www.myfonts.com/search/fleurons/fonts/

Simply pick the glyph you want and set it like you would any type character.
If you really want to draw your own, it simply takes practice with the pen tool.
Answer: Those specific ornaments are part of Bickham Script Pro, which either came with your copy of InDesign (if you have a perpetual license version) or can be installed from Typekit (if you're on Creative Cloud).
Many OpenType typefaces include ornaments. To find them, use the Glyphs panel (Type > Glyphs) and use the dropdown selector to view "Ornaments" and "Private Use Area," which are the usual places to find them.
In many cases, your best bet is to use an ornament that is built into the typeface you're using. You can also find flourishes, fancy corners, swirls, swooshes and other decorative elements of varying quality on any stock image site or some of the freebie sites. Just Google variations on "ornamental graphic" and you'll find lots.
If you want to roll your own, InDesign, versatile as it is, is not the right workshop to be doing it. Illustrator has many more tools for this kind of work, and if you have an iThing, the new Shape touch app includes many drawing aids such as French Curves to make the job of creating that kind of curve much more accurate and straightforward.

Creating nice curves with InDesign


Ubuntu 14.04LTS on ASUS wifi disconnecting and reconnecting

Question: Hi im a beginner and started out with replacing my operating system with ubuntu 14.04. It was working fine until recently nothing that I know of has been changed. When I use rfkill list i get: 0: phy0: Wireless LAN soft blocked: no hard blocked: yes 1: asus-wlan: wireless lan soft blocked: no hard blocked: no 2: asus-bluetooth: bluetooth sb:no sb:no
when i close my laptop lid and reopen it, the wifi connects to the network and shows that it is not hard blocked anymore. Any help or suggestions would be appreciated.
iwconfig gives me eth0: no wireless extensions; lo:no wireless extension; wlan0: IEEE 802.11bgn ESSID:"XXXXXXX" power management is off.
when i run lspci -vnn | grep Network i receive: 02:00.0 Network controller [0280]: Ralink corp. RT5390 wireless 802.11n 1T/1R PCIe [1814:5390]
and time is kinda important,not that anyones elses time isnt important, and i know i was stupid for this but i installed this on my laptop i use for school and work and need it for monday.
edit:when i run lsmod | grep asus i get:
asus_nb_wmi  16990  0
asus_wmi  24191  1 asus_nb_wmi
Answer: http://ubuntuforums.org/showthread.php?t=2181558
echo "options asus_nb_wmi wapf=4" | sudo tee /etc/modprobe.d/asus_nb_wmi.conf
but your answer helped me either way thanks again bro would give rep if i could lol.
thanks and rep go to Jeremy31 for help.


Would OpenElec Run Faster Off an External Hard?

Question: I know the Raspberry Pi Requires an SD Card with the files to boot OpenElec up on it, however considering I am using a class 4 SD card with OpenElec on it. Would I see any performance gains from running OpenElec off my external desktop hard drive connected to a USB port on the pi? My other assumption would be that I would have to create a partition on the drive, so that I could still use it with windows?
Answer: SD card reads on the pi max out at 20 MB/s; most cards will supply close to this regardless of class. Write speed is generally much less significant. You should be able to get faster reads (and writes) from an external drive.
However, that probably won't speed performance unless your RAM is always maxed out, since the system uses free RAM as a file cache for frequently accessed things.
If your system does have its RAM maxed out all the time, you will notice a performance gain if you can free 50-100 MB up regardless of whether or not you use an external drive.  If you cannot free this up, using an external drive still won't make much difference on a media center; storage I/O is inevitably a bottleneck sometimes, but not often enough to make it significant if the major activity is streaming media (which occurs at much less than 20 MB/s anyway).
On a database or file server, where large amounts of data are being frequently accessed as fast as possible this would be meaningful.

My other assumption would be that I would have to create a partition on the drive, so that I could still use it with windows?

Not clear what you mean here, but if it is a shared NTFS partition, sure you could do that.  The native linux ext4 format probably performs better, but I believe it is a hassle under windows
Comment: What I meant is if I put a partition like NTFS on the external hard drive and installed the necessary files for OpenElec on it the rest of the hard drive could be accessed normally by windows
Comment: So you mean two separate partitions?  That's fine.  Windows may not recognize the openELEC one properly, but should leave it alone anyway -- note there are some potential complications if you want to *boot* windows from that drive.


What are motion graphics?

Question: What are motion graphics?  What software can I use to create them?  What should someone trying to produce a video with motion graphics know?
Comment: This is intended as a canonical Q/A for the large number of very similar motion graphics questions we get.  Please feel free to edit the question and post your own answers to help cover the subject as best as we can.
Answer: Motion graphics is a form of 2d or 3d animation based around moving graphics.  It can include such things as moving titles, animated presentations and graphs, animated background (motion backs), whiteboard animations, animated product demonstrations and more.
It can range in complexity from relatively simple (such as basic moving titles) to extremely advanced multi-layered projects laid out in 3d using numerous interacting objects.  Software such as Adobe After Effects and Apple Motion are often used for producing motion graphics.  It is also possible to produce some motion graphics in Adobe Flash, though it is more designed for pure 2D animations.  At the time of this writing, there wasn't much in the way of good open-source motion graphic software.
Motion graphics can be deceptive in the apparent simplicity when well done.  If you have no experience in the field, you should be prepared to encounter a lot of issues and challenges when trying to make a really good looking motion graphic.  It takes animation, graphic design and editing skills to produce a very high quality motion graphic and the tools themselves are complex beasts that can take a while just to learn the tool-set.
If you are looking for a professional looking motion graphic on a quick time table and you have no experience in the field, your best bet is likely to hire an experienced professional to do the work for you.  If you are looking to do it for your own purposes, it is an interesting field, but be sure not to set your bar too high.  Start simple and learn from there.  It is a field that can take months to years to get good in.

What are motion graphics?


Haglund exostosis after one day of bad shoes?

Question: Yesterday I walked one day one shoes a bit tight near the heel. In fact I felt this from the start of the day. My little brother developed Haglund exostosis once. Is it possible to develop a Haglund's deformity after only one day of bad shoes?
Answer: Haglund's deformity is mainly genetic and depends on your type of foot. As your brother has already had this, I suspect you might have the same type of foot and therefore have a higher risk of getting the deformity that others. Also, it's

When most people first notice Haglund's deformity, it is because the
  skin, bursa and other soft tissues at the back of the heel gets
  irritated as the knot of bone rubs against the heel counter in shoes

You might have had a latent Haglund's deformity, but haven't noticed it until you used bad shoes.
I would strongly advice you to visit a professional, and not rely on "internet experts" for this. The price you have to pay for following a bad advice here is too high to risk it.
However, once the pain and inflammation have gone a way, there are preventive measures you can take:
Prevention of Haglund's Deformity
Once your pain and inflammation is gone, you can try to prevent Haglund's deformity by [1]:

Wearing the best shoes for your foot type. You should high-heels and pumps if possible.
Wear orthotics (custom arch supports) or over-the-counter orthotic devices
Perform frequent Achilles tendon stretching exercises to prevent it from becoming tight again
Avoiding running uphill when training. Try to run on softer surfaces and avoid concrete.


Limit FTP connections by area

Question: Is there any (simple) way to deny FTP connections based on the general physical location? I plan to use FTP as a simple cloud storage for me and my friends. I use an odroid c2 (similar to raspberry pi but uses arm64 architecture) running Debian 8 with proftpd and ufw as my firewall. Ftp server runs on a non-standard port which I prefer not to mention here. I want to do this to increase the security of my server.
Answer: Use pam and geoip module

This PAM module provides GeoIP checking for logins. The user can be
  allowed or denied based on the location of the originating IP address.
  This is similar to pam_access(8), but uses a GeoIP City or GeoIP
  Country database instead of host name / IP matching.
Answer: You could do this to some extend with CIDR[1] IP ranges since these can be mapped to countries[2].
You can then use an app like iptables[3] to control any incoming traffic on any port (independent of the protocol). This tutorial describes it in some more detail.
In combination with CIDR the command would look something like this:
iptables -A INPUT -s 22.214.171.124/24 -j ACCEPT

Depending on how many friends you have, you may be able to narrow this down by the IP blocks reserved by your friends' Telco/Internet provider.
(BTW CIDR rules are what Amazon's cloud services use, and they highly recommends to make AWS instances more secure in this manner. So your question has a lot of merit, but since I just joined I cannot up-vote it - or rather my vote doesn't show).
Additional links for reference that I cannot embed as I only get two links to use as a newbee:
1) en.wikipedia.org/wiki/Classless_Inter-Domain_Routing
2) blog.erben.sk/2014/02/06/country-cidr-ip-ranges
3) en.wikipedia.org/wiki/Iptables
Answer: I would suggest using ProFTPD's mod_geoip module, to at least restrict connections to the geographic content/country (and city, if you can).  This is similar to @Ipor's answer, using the same geoip libraries/databases, except that it doesn't require PAM configurations, and is more flexible.

Limit FTP connections by area


Variable increment step in WinForm NumericUpDown control depending on whether Shift/Ctrl/etc. are pressed

Question: What I want is somewhat similar to what happens in a WinForm designer in Visual Studio, say VS2010. If I place a button and select it and use arrow keys, it will move around by 5 pixels in whatever direction I chose by pressing the right key. Now, if I hold either a Shift or a Ctrl modifier as I do that (forgot which one, sorry), then the button will move only by 1 pixel at a time.
I want this to happen with my NumericUpDown control in a C# WinForm app. Let's say a default increment is 100.0, and a smaller increment is 10.0. An even smaller increment (if possible) can be 1.0. Any hints on how can I do that?
Hopefully I do not need to ask this as a separate question: I am also toying with the idea of having the increment be dependent on the current value entered. Say, I can enter a dollar amount anywhere between 1 and 100 billion. I then want the default, small, and smaller increment  values be dependent on the value entered. I can figure out the exact formula myself.
Answer: Derive your own class from NumericUpDown and override the UpButton() and DownButton() methods:
using System;
using System.Windows.Forms;

public class MyUpDown : NumericUpDown {
    public override void UpButton() {
        decimal inc = this.Increment;
        if ((Control.ModifierKeys & Keys.Control) == Keys.Control) this.Increment *= 10;
        base.UpButton();
        this.Increment = inc;
    }
    // TODO: DownButton
}

Tweak as necessary to give other keys different effects.
Answer: This is a bit crude but it's a little simpler than the other answer (not better though) and for the 2nd part of the question you just need to replace the 100/10/1 with a calculation based on the current value.
Set the default incrememnt to 100 (or whatever) and in the keydown event of the NumericUpDown (nUpDown)
private void nUpDown_KeyDown(object sender, KeyEventArgs e)
{
    if (e.Control && e.KeyCode == Keys.Up)
        nUpDown.Value += 10;

    else if (e.Control && e.KeyCode == Keys.Down)
        nUpDown.Value -= 10;

    else if (e.Shift && e.KeyCode == Keys.Up)
        nUpDown.Value += 1;

    else if (e.Shift && e.KeyCode == Keys.Down)
        nUpDown.Value -= 1;
}

Comment: keydown will repeat if the key is held whereas keyup will only fire when it is released
Comment: Thanks, is `_KeyDown` preferable to `_KeyUp`?


QGIS Browser - Location bar

Question: Is there a way to have a location bar (or breadcrumb trail) to show the location path in QGIS 3 browser panel? Most importantly in order to copy-paste a location and go to it directly without having to manually navigate the tree ...
Comment: Can't find anything, and I can't find a plugin that can tweak the browser. It might be possible with a python plugin but I'm not sure how the UI would work. Right click an item and get "Copy path to clipboard" would work one way. Maybe it needs a line item like the "filter" button generates....
Comment: Thanks @Spacedman, ineed for a second I thought I had found the way when I activated the filter button, but unfortunately it doesn't accepts path as filter. Then may be time to open a feature request :). Just wanted to make sure the functionality is not already existing but hidden somewhere..
Comment: I'm looking for the same feature. That's how I get around in ArcMap browser. Upvoting.
Comment: For reference, here is the feature request on GitHub: https://github.com/qgis/QGIS/issues/36872
Answer: This method works on Windows.
Right click on Favorites > Add a Directory > brings up a Windows Explorer window where you can paste or type a file path into the location bar

Click OK to add the filepath to the list of Favorite directories.
Comment: Thanks @csk, still not exactly what I was hoping for (I was more thinking of an ad-hoc, temporary navigation) but better than nothing. Also a feature to be taken directly to the file location (in QGI Browser) when clicking on the layer path in the Layer Properties > Information would be nice (sometimes files are so nested that is bore-some to navigate manually)
Comment: This is the feature that QGIS actually has. If you want new features, you can always make a feature request on their website.

QGIS Browser - Location bar


Ubuntu 16.04 LTS Freeze but can move mouse Help!

Question: I have Ubuntu 16.04 LTS installed and, I left my computer downloading something and a few minutes later my computer freezes and I can still move my mouse but, Nothing would work Is there a way to fix this? And is this a Hardware problem? I have a HP Pavilion 500 223w and Geforce Graphics card (Forgot what model) Can anyone help? Thanks! In the logs it says Feb  5 15:33:31 tristan-500-223w org.gnome.ScreenSaver[2894]: ** (gnome-screensaver:3287): WARNING **: Couldn't get presence status: The name org.gnome.SessionManager was not provided by any .service files
Comment: Did your pc freeze in the lock screen (password prompt), or regular window? Can you please add a screenshot, or explain the `freeze` a little better?
Comment: At the desktop I was logged in.
Comment: Well, just a few minutes ago I got some Graphical glitches then  it froze But I can still move my mouse.
Comment: A solution for me is to change in a Terminal (e.g. ctrl+alt+F1)
login as a normal user
doing *sudo lightdm restart" or "sudo lightdm force-reloade". Doing this way closes all open applications and i have to login again but I don't have to reboot the system.
Hope this may help a little
Answer: It sounds like a GPU hang. Your system may not be properly halting display services when sleep activates and that would result in a paused display. Ensure your drivers are up to date, and if possible, check for any listed bugs with that particular software revision. I think ctrl+alt+bckspc restarts the display+session manager, but I'm not sure what's different between Wayland and Xorg. Rebooting is my only temporary solution.
Comment: I tried installing some drivers but, I could not login after resulting in me reinstalling ubuntu. And, Could this GPU hang break my Computer? like having to hold down the power button in stead of shutting down (and I cannot when it freezes) Thanks!
Comment: A GPU hang won't harm your computer as it only involves display output, however hard shutdowns are a possible danger and the necessity to do so is unfortunate. In the case this isn't a GPU hang, I'd suggest checking your hardware's compatibility with Ubuntu. Does this issue only happen after leaving the system running for a while? Or does it happen at any time? If it's a random thing that occurs even during active use, it's likely more complicated than a display pause.
Comment: Well, It has not froze in a while now, It froze on me like 3 or 4 times. here is what the log says
Comment: Feb  5 20:33:56 tristan-500-223w org.gnome.ScreenSaver[3176]: ** Message: Lost the name, shutting down.
Feb  5 20:34:02 tristan-500-223w gnome-session[3321]: Nautilus-Share-Message: Called "net usershare info" but it failed: Failed to execute child process "net" (No such file or directory)
Feb  5 20:34:03 tristan-500-223w systemd-timesyncd[2502]: Synchronized to time server 184.108.40.206:123 (ntp.ubuntu.com).
Feb  5 20:34:05 tristan-500-223w org.gtk.vfs.Daemon[3176]: ** (gvfsd:3237): WARNING **: dbus_mount_reply: Error from org.gtk.vfs.Mountable.mount(): Failed to retrieve share list from
Comment: I'm certainly no expert, but just a few scans over this gives me the idea that the issue is suspend-resume. The machine isn't able to call the resume services properly after it sleeps/suspends. I don't know how to fix this. I'd suggest updating your system and using the tag fix-missing. Other than that, I'd just check to see if your power manager AND your screensaver are both trying to handle suspend. Disabling the screensaver is all I can really think of. For anything more advanced, I defer to the more complex knowledge of another forum user. Hope I was of some use.
Comment: My computer just got some graphical glitches and froze hmm..
Comment: I was also using my computer at the time of the freeze


Is there any way to check the distance of an object to a locked layer in sketchapp?

Question: I am trying to see the distance of an object to a locked layer in sketchapp; however it just doesn't show the distance once the layer is locked. Do you know whether there is any way to measure the distance? Thanks millions ^^
Answer: From the sketch documentation:

With a layer selected, hold the Option key and hover over another layer. You will see that Sketch displays the distance between the two layers. When measuring against other layers, you can also hover over the Layer List.

What they fail to mention is that this works for locked layers: if you hold the Option key and mouse over the locked layer in the layers list, you'll see those familiar and oh-so-useful distance Smart Guides.


How to configure a router as a dhcp server for vlans through a Layer 3 switch?

Question: I would like to know what commands to type in the different switches and the router to  to make the router function as a dhcp server for each PC in seperate vlans .
I know to create the dhcp pools in the router and I would like to use the layer 3 switch for inter-vlan routing.
Answer: Simply configure a DCHP relay on the SVIs with the ip helper-address <dhcp server address> command.
Alternatively, you can configure the DHCP server on the layer-3 switch.

The built-in DHCP servers are pretty lame. For a real network, you should use a real DHCP server.
Comment: How do I use the L3 switch for routing the vlans and send the PCs DHCP requests ? Do I need to make a vlan between the router and L3 switch ?
Comment: That is really a different question altogether. Normally, you set up a routed link (`no switchport`), rather than a VLAN (`switchport`). Remember that a layer-3 switch has a built-in router, so you need to tell each router about the networks on the other side of the other routers. You can statically configure routes on each, or you could use a dynamic routing protocol.
Comment: Which commands should I type  in the router and L3 switch to have DHCP working on the PCs belonging to seperate vlans ? I setup the dhcp pools and default router on the router already.
Comment: It is just the DHCP relay that I explained in the answer, but you need to have routing set up properly. That is a completely different question, and it will need much more information. Just start a new question about routing. DHCP and routing really different questions. DHCP relay requires that the routing to be working.
Comment: To configure the DHCP I need to give an address to my router's interface and add that address to the L3 switch with ip helper-address ? I also need ip routing enabled on the switch ?
Comment: Your question says that you want the layer-3 switch to do the LAN routing, and that is a good choice. That means you need a routed link between the layer-3 switch and the router, and you need to somehow tell each how to reach the networks on the other side of the other router. Once you have the routing working, it is a simple matter to add the helper address to the SVIs. Your question is about DHCP, but you need to ask a new question about the routing. That is a very different question tan you have asked here, and comments are not for discussion, we have [chat] for that.
Answer: Cisco documentation Configuring the Cisco IOS DHCP Relay Agent explains:

A DHCP relay agent is any host that forwards DHCP packets between
clients and servers. Relay agents are used to forward requests and
replies between clients and servers when they are not on the same
physical subnet. Relay agent forwarding is distinct from the normal
forwarding of an IP router, where IP datagrams are switched between
networks somewhat transparently. By contrast, relay agents receive
DHCP messages and then generate a new DHCP message to send out on
another interface. The relay agent sets the gateway address (giaddr
field of the DHCP packet) and, if configured, adds the relay agent
information option (option82) in the packet and forwards it to the
DHCP server. The reply from the server is forwarded back to the client
after removing option 82.
The Cisco IOS DHCP relay agent supports the use of unnumbered
interfaces. For DHCP clients connected though the unnumbered
interfaces, the DHCP relay agent automatically adds a static host
route once the DHCP client obtains an address, specifying the
unnumbered interface as the outbound interface. The route is
automatically removed once the lease time expires or when the client
releases the address.
ip helper-address address
Example: Router(config-if)# ip helper-address 172.16.1.2
Forwards UPD broadcasts, including BOOTP and DHCP.
•The address argument can be a specific DHCP server address, or it can
be the network address if other DHCP servers are on the destination
network segment. Using the network address enables other servers to
respond to DHCP requests.
•If you have multiple servers, you can configure one helper address
for each server.


What happens when an electric dipole is placed in a uniform magnetic field?

Question: I am currently trying to understand the classical consequences of more than one charged particles in a magnetic field. So a thought experiment which came to mind was an electric dipole being placed in a magnetic field and given a slight push. Since there is Coulomb attraction between the two individual monopoles, and the magnetic forces acting on the two of them are in opposite directions due to their charge, does that mean they will eventually meet and annihilate (assuming no radiation, relativistic or quantum effects)? Does that mean a dipole is unstable in a magnetic field? Is that physically reasonable? Thank you!
Comment: Just write the equation of motion for each single particle plugging in the electric and magnetic contribution, and solve them: in general the result depends on many things.
Comment: Hello, could you talk a bit more about the many things you are referring to?
Comment: I think it's probably worth noting that a dipole is usually assumed to be rigid. That is, a dipole is not even a stable electrostatic situation if you don't fix the distance by other forces.
Answer: First point: there is not ANY static distribution of electric charge that is stable under its own electrostatic forces. So either your two charges have to be held apart from one another by a rod or spring or gluey substance or something, or else they will not be stable even in the absence of any external field (of whatever kind).
Second point: opposite charges do not always annihilate. For example, when an electron meets a proton, they do not annihilate; rather one settles into a spherical distribution around the other (neutral hydrogen atom in its ground state). On a classical model (i.e. ignoring quantum physics) they would spiral around one another and eventually stick together and to avoid inconsistencies you would need to invoke a model in which they are not point-like. An electron and positron, on the other hand, would annihilate.
Finally, then, if we place two classical particles of opposite charge near one another in an external magnetic field, with no rod keeping them apart, then how will they move? If released from rest then the forces on them are initially purely Coulomb attraction so they begin to accelerate towards one another. If they are moving in the plane perpendicular to $\bf B$ then they begin to experience a magnetic force which, in the first instance, is in the same direction on both (since they have opposite velocity and opposite charge). If the $\bf B$ field is weak they each follow a curved path and soon collide. If the $\bf B$ field is strong I think (but have not calculated) that they each follow approximately a cycloid (i.e. curly line) imposed on a more gently curving shape as they move towards one another.
If the initial position is such that the particles are separated along the direction of $\bf B$, then if they start from rest they never get any magnetic contribution to the force (because their velocities are aligned with $\bf B$) so they move directly towards one another. If you set them off with a push to the side, then they get opposite magnetic forces and I guess they will do a beautiful little spiral dance as they move towards one another, and they may never collide ... a nice project for a fun computer simulation if anyone has the time?
Comment: Also among the list of culprits in your first paragraph, next to the rod and the spring: quantum mechanics.
Comment: Yes indeed: the stability of rod, spring, glue all rely on quantum.
Answer: i think that if the direction of motion is not parallel to the direction of the magnetic field,the dipole experiences a torque and then a centrifugal acceleration that will caused the dipole during its rotation, radiates too.


AES/DES question about determine a key

Question: I have a question. If you receive a DES encrypted message for which you would NOT recognize the plaintext if it were decrypted, is there any way to potentially determine the key if all keys are likely? What about for AES?
Comment: Depends... With authenticated modes of encryption it is easy to confirm the key and DES keys could be recovered (AES keyspace is too large). Even with e.g. CBC and a padded message it could be possible, if message length is known (7-8 byte DES padding is probably unique to a single key).
Answer: No. For any key $k$ your ciphertext $c$ has a corresponding plaintext $p$ (since block ciphers are families of bijections). Hence, since you can't (in)validate plaintexts, you can't discard any possible key.
Or, in other words: If someone claimed the right key was a certain $k$, you had absolutely no way to ever prove them wrong.
Comment: Padding is missing from this answer. Usually it's considered part of the algorithm, if just in cryptographic API's. Otus also mentioned in the comment below the question.

AES/DES question about determine a key


How did the TARDIS blow up at the every point of the universe?

Question: In "The Big Bang" episode the TARDIS was blowing up at the every point of the universe and because of that reason the Doctor could throw Pandorica into the TARDIS and recreates the universe. What does it mean to explode at "every point in the universe"? The TARDIS blew up but why at the every point of universe?
Answer: The Tardis explosion caused a shock wave in time that led to a "total event collapse" in "The Pandorica Opens".  I think you just have to accept that whatever makes a TARDIS work was sufficiently powerful to destroy space-time if it exploded in such a manner.
To the question "what does this mean". This manifested itself as every star in the universe exploding - presumably in a manner that this would appear simultaneous at Earth if the special effect is taken literally.  That is - a star 4 light years away exploded 4 years in the past and a star ten years away ten years in the past - such that the whole universe goes dark at the same origin moment.
(Note in Doctor Who time can be rewritten in an instant - so those explosions in the past didn't exist until they were caused by the TARDIS.)
However this event also spread cracks in space-time prior to the explosion which was the main plot of Matt Smith Doctor 11's first season.  He was dealing with cracks before the event that caused them happened. In fact the efforts to assassinate the Doctor to prevent the cracks - one of which was blowing up the TARDIS - paradoxically caused them to happen in the first place!
Ultimately the solution was to reboot the universe using the pattern of the old universe.  Thus resulting in a crack free universe and Amy's parent's existing again.  The memories of the season -  which really never happened - as a forked branch in time - gets overlaid onto the memories of the participants like Rory and they proceed to new adventures.  Meanwhile the Silence proceed to plan a new way to deal with the Paradox of the Doctor on Trenzalore.
The transcript of the "Pandorica Opens" from
Chakoteya:

[Pandorica chamber]
(River tries frantically to escape the Tardis as the Doctor is dragged closer and closer to the Pandorica, then fastened into the seat inside it. His arms, torso and head are clamped in place and all his old enemies stare at him.)
DOCTOR: You lot, working together. An alliance. How is that possible?
WHITE: The cracks in the skin of the universe.
STARK: All reality is threatened.
CYBERLEADER: All universes will be deleted.
DOCTOR: What? And you've come to me for help?
STARK: No. We will save the universe from you!
DOCTOR: From me?
CYBERLEADER: All projections correlate. All evidence concurs. The Doctor will destroy the universe.
DOCTOR: No, no, no. You've got it wrong.
CYBERLEADER: The Pandorica was constructed to ensure the safety of the Alliance.
WHITE: A scenario was devised from the memories of your companion.
STARK: A trap the Doctor could not resist.
WHITE: The cracks in time are the work of the Doctor. It is confirmed.
DOCTOR: No. no, no, not me, the Tardis. And I'm not in the Tardis, am I?
WHITE: Only the Doctor can pilot the Tardis.
DOCTOR: Please, listen to me!
WHITE: You will be prevented.
DOCTOR: Total event collapse! Every sun will supernova at every moment in history. The whole universe will never have existed. Please, listen to me!
CYBERLEADER: Seal the Pandorica.
DOCTOR: No! Please, listen to me! The Tardis is exploding right now and I'm the only one who can stop it! Listen to me!
(The Pandorica closes.)
[Tardis]
(River opens the Tardis doors to discover she is parked right up against a rock wall.)
RIVER: I'm sorry, my love.
(The Tardis explodes. As Rory weeps over Amy's body, every star in the universe goes KaBOOM.)
Comment: In the future please mark quotes as such (I.e. a > at the start of each paragraph) and also make them readable with line breaks. Previously that quote was just one long paragraph of mess and wasn't really legible.
Answer: The TARDIS is infinite space and time pressed into a police box, at a single time.  When you take infinite space and time and cause it to explode outward, that shatters the fabric of reality at every point in space and time.
Comment: A short answer woul d be that real physics and cosmology often seems very weird, nonsenical, and paradoxical to most of us.  And Dr. Who physics is many times weirder and doesn't make sense to physicists and scientists.
Comment: Could you give more detail about "TARDIS is infinite space and time"
Comment: @M.A.Golding [Nobody ever said we're about real-world science](https://scifi.meta.stackexchange.com/q/7364/141465)... ;)
Comment: @NastasyaFilippovna As confirmed in _Journey to the Center of the TARDIS_, the core of the TARDIS consists of a star at the point of collapse, emitting infinite energy for that exact moment.  Thus, the TARDIS has infinite power and can use that to create infinite space inside.


Recover contacts from Galaxy S2 when saved to an email

Question: If I saved my contacts to an email on my Samsung Galaxy S2, and my email account was deleted on my phone, is it possible to recover my contacts?
Comment: If they're saved to your account then can't you just add it to your phone again or export the contacts from it? It sounds like you wouldn't need to "recover" anything, just retrieve them from the email account.
Answer: Only if your email was sync'ed before you deleted the account from your phone. Check from a PC in the email account you used has the message in "Sent" folder (or inbox if you sent to yourself).


Roll back data on a record if rejected via approval process

Question: Is there a way to roll back the changes (data) if the record is rejected by the approver using standard approval process in salesforce? I've checked and it seems there is no OOB to do this. Is trigger the only way to roll back the record data in this case?
For example: Contact record with email (firstname.lastname@example.com) > Email modified (as firstname.lastname@example.com) > record sent for approval > approver "Rejects" it. Now i want the contact record with data (rolled back) as email@example.com
Comment: on how many fields do you want to apply an approval process? Just Email? Or all Contact fields?
Comment: @Guy I was about to ask him a same question, If there are less number of fields then Old value should be kept in separate fields and later can be used to update Original fields with Old values on Rejection action taken by Approver.
Comment: In my case, its around 10-15 fields. From @Devendra 's comment, it seems its not gonna be OOB and a custom logic (oldMap) to be used. Correct me if am wrong.
Comment: It would not be only OOB. It would be combination of both Customization and Configuration.
Comment: Even a trigger won't work as the intitial change and the reject later on will be 2 separate transactions, thus during the reject, the oldMap will not contain the original values anymore.
Answer: If you want to do a rollback of a large number of fields (or actually an entire object) you can't use workflow or triggers anymore but need to use APEX in combination with a datastore to store the old data that could be needed to roll back.
I'd suggest one of these solutions:

create a full copy of the record and store it in another place, invisible for the end user. If you have an object with public readability, you might even need to create a separate custom object to store the data. Then add some APEX to create and cleanup the pseudo-object. Then have the APEX called by a trigger which in turn is triggered by an approval process.
create a long text field on the object and use APEX to write a JSON string of the object into the text field. Then if the approval is rejected, use APEX to generate back the old record from the JSON string. The triggering happens the same way as for #1.

2 is easier more lightweight but you could run out of space in your long text field if there's a lot of data to save..
Comment: I'm glad I've never had to deal with this requirement.  #1 would mean dual maintenance when new fields added and a clever rollback that exploited describe information.  #2 is easier but to be generalized, might need to overflow into multiple 128K long text fields - though you still end up having to avoid processing formula fields and auto-number fields.  What a mess. Better to avoid the problem in the first place via application design.
Comment: fully agree with you @cropredy
Comment: @Guy Thanks for the response. I also thought about the approach similar to option 1 which you suggested. Here, in my case, i dont think ive to go for another object. Instead i can have the duplicate fields (say, Formula fields and not visible to users) and populate the values there. Then, once the record gets rejected, will update a field (say, status as "Rejected") > Fires a after update trigger > Logic inside it to fetch values from duplicate fields and assign it to respective original fields. How about this?
Comment: Yes that is an option as well if the amout of fields is reasonably limited. Probably not formula fields but fields of the same type as the original ones. Then you could even workflow (or even the approval process) to copy the values back and forth. None of the solutions is very elegant, though, as already stated by @cropredy.
Comment: That's right! Maybe Salesforce has to do something about this.


Cloud Storage with API that support file detection

Question: Hi I am looking for some cloud storage (Dropbox, SkyDrive, Google Drive, etc) that has a decent API (C#) and has some sort of subscription service, so that when a new file is added it will inform me of it, so I can pick it up and work with it. Does this even exist or will I have to poll the cloud storage every x minutes.
Answer: For Google Drive this has been asked here already.
Basically this is not available yet on the Drive API but we have got it planned for a future release. In the mean time you should check out the changes feed of the Google Documents List API that is very convenient for polling.


What's the ranking algorithm of SO?

Question: Will editing the question make it rank forward or not?
Answer: Editing the question will rank it forward, being the newest until of course another one gets asked, answered or bumped, unless the question has a reputation of -5 or less. The order in the Recent QUestions/Active tab is by last activity date. Votes do not count towards that activity, neither does flaging or voting to close, or commenting.
Have a look at these questions about bumping questions and getting attention and the FAQ towards the bottom.
Comment: Editing a post will not move it to the top of the Newest Questions list, only to the Active list.
Comment: To make it further,will it become the newest after editing?
Comment: I mean,rank first by date
Answer: From the FAQs :

What if I don't get a good answer?
In order to get good answers, you have
  to put some effort into the question.
  Edit your question to provide status
  and progress updates. Document your
  own continued efforts to answer your
  question. This will naturally bump
  your question and get more people
  interested in it.
If, after two days, you still don't
  have an answer you like, you can offer
  a bounty. Slice off a bit of your own
  hard-earned reputation -- anywhere
  from 50 to 500 -- and attach it to the
  question as a bounty. We'll even throw
  in 50 reputation to sweeten the deal.
  The bountied question will appear with
  a special icon in all question lists,
  and it will also be visible on the
  home page Featured tab.
Once initiated, the bounty period
  lasts seven days. If you mark an
  accepted answer, your bounty is
  awarded to the answerer (do note that
  accepted bounty answers are permanent
  and cannot be changed). If you do not
  accept an answer in seven days, the
  top voted answer will automatically
  become the accepted answer, and half
  your bounty will be awarded to that
  answer. You will always give up the
  amount of reputation specified in the
  bounty, so if you start a bounty, be
  sure to follow up and accept the best
  answer!
Of course, bounty awards, like all
  accepted answers, are immune to the
  daily reputation cap and community
  wiki mode.

What's the ranking algorithm of SO?


Dupe of question originally on Sound Design

Question: Free music for commercial use project?
is marked as a dupe of https://sound.stackexchange.com/questions/23059/where-to-find-free-music
but the latter appears on Sound Design. Should there be a Video Production version of this question as the original?
Answer: I think in this case we are probably ok with relaying it since there are already posts marked as dupe of it.  This is an odd artifact of the fact that half of sound design and video production were once the same site but then the primarily sound related questions were migrated off to Sound Design.  If it's purely finding sound, it probably is only borderline on-topic anyway vs being a Sound Design question which is why the predecessor was migrated.
Comment: Actually, when I think about it, it's a shopping cart type question and is going to attract link-only answers so it's probably a fairly low-quality question anyway.
Comment: Also a good point


Will iPhone SE price likely be reduced 1 year after its debut?

Question: the iPhone SE came out last March, and rumour is that it won't be updated this year. Will it likely see a price drop this cycle? Is it best to hold off till March to buy one?
Comment: Although its not certain without inside information I don't see this question as opinion-based; anyone with knowledge of Apples historical pricing approach can answer it.
Answer: Only Apple knows the answer to this question.
While one may think that Apple could lower the price it could in fact go up: Depending on the country you are living prices have been increased in the past due to currency fluctuations.
IMO it's unlikely that we will see a price drop for the iPhone SE. For Apple it's a device with a really low profit margin compared to other products. It has most of the iPhone 6s' internal specs so Apple is in no hurry to upgrade it either.
I think if you need a new iPhone because your old one is broken, buy it now.


6 month stay in canada

Question: I own and rent a home in Canada. Does my 6 month stay begin the day I enter Canada or start over on Jan 1 - Dec 31 every year.  I mean is the 6 month stay based on the calendar year?
Answer: When you enter Canada you are given a certain period of stay.  This is normally six months.  That is calculated from the date on which you enter.  Your question implies that you are wondering whether you can enter during the second half of a year and then stay until the end of June the following year.  Generally speaking, you cannot do that under the normal rules for temporary visitors.
That all depends on immigration rules.  Someone in your situation may also need to worry about tax rules.  I don't know how Canada defines tax residence, but many countries do define it in terms thattake the calendar year into account.  If that is your concern, you'll probably geta better answer on Expatriates.

6 month stay in canada


Chat markdown in comments doesn't work

Question: According to this help about comment formatting, the [chat] markdown should create a link to the site chat. While the name expansion worked, the link leads to the rather general chat.stackexchange.com instead of our chat.
Happened on this comment
Comment: Funny, the chat link in the comment you linked links me to the mechanics.SE chats.
Answer: This seems to be by design:

<code>[chat]</code> – link to the current site's chat site (http://chat.stackoverflow.com/ for SO, http://chat.meta.stackexchange.com/ for Meta SE, http://chat.stackexchange.com/ everywhere else, that last one showing a list of active rooms from the referring site), the link text being "{site name} Chat".

There is a feature request to allow behaviour more like what you suggest (Be able to specify a particular room in the chat magic link on Meta.SE) and a similar question on Meta.SE about this behaviour in particular.
Comment: It's a strange design

Chat markdown in comments doesn't work