Customize Walker_nav_menu to show posts if item is category

Question: I would like to customize the nav menu walker so that when it encounters a category it automatically makes the 5 most resent posts children of the menu item.  Is there a way to dynamically add items to the menu object or it better to have a conditional in the start_el function?
Comment: `start_el`-- aka, extend the walker.
Answer: You could either extend the Walker_Nav_Menu walker class (i.e., the start_el function is sufficient, as already mentioned).
Or you could hook in when the original output (i.e., the category) has been created. That would be the walker_nav_menu_start_el hook.
For instance like so:
function wpdev_139801_start_el( $item_output, $item ) {
    if ( isset( $item->object ) && $item->object === 'category' ) {
        // Set up your query here,
        // then concatenate the output to $item_output
        // You could do this using wp_get_archives()
    }

    return $item_output;
} // function wpdev_139801_start_el

add_filter( 'walker_nav_menu_start_el', 'wpdev_139801_start_el', 10, 2 );

Comment: This will add the posts in a list if I choose but will not put the posts threw the walker.  Therefore the posts will not have the same classes that the Walker_nav_menu puts on the elements by default.  Will I just have to manually add those classes in the wpdev_139801_start_el function after my query when contructing my ouput?
Comment: Ah, okay, now I see what you are trying to do. I didn't think about actually including the category posts into the walker output. To do so, you might want to use some other hook, and adjust the actual objects for the walker function. Have a look at the [`wp_get_nav_menu_items`](https://core.trac.wordpress.org/browser/tags/3.8.1/src/wp-includes/nav-menu.php#L549) hook.
Comment: I was looking at the nav menu object itself.  Dynamically creating objects and inserting them was kind of what I was think but didn't know if that was possible. Specifically because the dynamically created item would not have an Object ID that corresponded to anything with a nav_menu taxonomy.
Comment: Well, yes, if you add your 5 (or so) posts to the nav menu items they won't have an item ID (in terms of the CSS class). But all the other (relevant) classes can/will be generated without a problem.


winform: binding problem with DropDownList

Question: I  have a table in access database file. I would like to show that table in DataGridView, i have a bindingsource which bind to the table. then DataGridView bind to bindingsource. I also have other controls(textboxs, comboboxs) which are bind to 'dataMember' of table through the same bindingsource. Everything work well. But when i changed 'DropDownStyle' of the combobox from 'DropDown' to 'DropDownList'. The binding is broken. The data in the combobox is not changed when i selected different row in the datagridview. However, when i changed the data in combobox, the data in the cell in DataGridView changed. Anyone has idea? Thank you very much!
The following is my code:

combobox1.Items.AddRange( new Object[]{
"Monday",
"Tuesday",
.....
.....
"Sunday"
});

bindingsource1.DataSource = dt; // dt is a instance of DataTable
combobox1.DataBindings.Add("Text", bindingsource1,"Day");

Comment: I think the behavior you're describing is "by design."
Answer: combobox1.DataBindings.Add("SelectedValue", bindingsource1,"Day");

[EDIT]
Add this:
comboBox1.DisplayMember = "Day";


TeXShop Can't Open Files

Question: My TeXShop has been acting out: I haven't been able to open files with it. I was able occasionally to open document class files, but I had no luck whatsoever with beamer files. I can open and compile all the files using TeXMaker. I've tried reinstalling the entire MacTeX package twice but the problem persists (I'm using the latest TeXShop and the latest Sierra on Mac). Someone from comp.text.tex suggested that I need to find and remove TeXShop's configuration file, but I don't know how. Any help would be appreciated.
Comment: What do you mean by "unable to open files"? Do you mean double clicking on them from within the Finder, or can you not open a file even if you choose "Open" from the file menu within TeXShop and then navigate to the file?  If it's the former, you should try what @CampanIgnis suggests. If it's the latter, then you should perhaps reinstall TeXShop (not MacTeX) by deleting the application (inside the TeX folder in Appplications) and also deleting `~/Library/TeXshop` (get to it via the Go menu in the Finder.)
Comment: I am not a OS-X-Expert, but have you clicked on a single TeX-file and then clicked 'cmd'+'i' and set the open option to TeXShop?
Comment: Sorry I wasn't being clear: when I double-clicked a beamer file, for example, then the file wouldn't open and I would get the eternal rainbow circle of death (which means that the computer is trying to load the file but just stuck in the process forever). I tried already the cmd+i. Will try reinstalling TexShop and report back here. Many thanks! (Hopeful here.)
Comment: Nope, still doesn't work. I reinstalled the TeXShop after deleting the application and the ~/Library/TeXShop. Please help!
Answer: I just came across your very same problem: remove \usepackage{pstricks}, if you had it before: after the update, it drives beamer crazy...I hope this helps. Otherwise look by exclusion for packages having a similar
effect. Good luck.
Mirko
Comment: Wow, thanks very much! It finally worked. Should we report this to pstricks developers?
Comment: @emil This is a problem with Apple's PDFKit, not really with TeX. We'll close your question as a duplicate (see link in last comment on your question.)

TeXShop Can't Open Files


Calculate Markup Percentage From Margin Percentage

Question: Well this is embarrassing, but if I'm aiming to sell a product for e.g. 30% Gross Profit, how do you calculate the markup percentage for it (e.g. 43%), in plain excel formula, taking the GP as an input.
Answer: You want to sell the item for $x.
The item costs you $20.
The difference between $x and $20 is your gross Profit and you want that to be 30% of the sale price.
<code>(x-20)/x = 0.3
   x-20  = x*0.3
   x-20  = 0.3X
   0.7x  = 20
      x  = 20/0.7
      x  = $28.57
</code>
so divide the cost of the item by (1-GP), here, 0.7 or multiply by 1.42857
Comment: feel free to re-edit, I added a tiny bit.


Using a standard color chart do I need to create profiles for my body/lens combo for multiple lighting conditions?

Question: I have the x-rite color checker and I've read that I should create profiles for each body/lens combination and some places even say for each lighting condition, though I have to wonder if that last part is necessary. It would seem to me that what the profile does is calculate the sensor's influence on color perception and correct for it, so why the need for multiple lighting setups? Would it make a difference if I used a light source that is a known color temperature (speedlites, for example)?
Answer: The lighting situation is far more important than the lens. (Lens colour casts are really very minimal these days.) You can try to use a dual-illuminant profile, but that will not account for the illumination spectrum that's actually present when you're taking a picture; it's just a basis on which to make gross colour temperature adjustments. If you want accurate subject colour, you need to measure how your camera sees known colours under that light. There is more difference between speedlights and tungsten lighting than Kelvin temperature and "tint" can account for.
Of course, that assumes that you want accurate subject colour, and that's not always the case. You are just as likely to want to see the subject colour as it is modified by the light (by say, a higher proportion of warm or cool tones, beyond the mere colour balance aspect). Flattening it out, or normalizing the response, then trying to put the warmth or coolness back in in your post-processing software will not often achieve the same effect.
Comment: This is especially the case if the lighting is less than full spectrum. You may even have two light sources that measure at the same color temperature, but one emits a very narrow spectrum around that single wavelength (such as a 2700°K sodium vapor lamp) while the other emits at all wavelengths but the light is centered at the same color temperature (2700°K full spectrum light).


"A great deal of trouble was gone through to ensure their safety" is the correct sentence in prepositional passive form

Question: My question is about passive voice for intransitive verbs like "go".
"A great deal of trouble was gone through to ensure their safety" is the correct
sentence in prepositional passive form.
Comment: The sentence is a bit obscure.
Comment: Related to (if not a duplicate of): https://ell.stackexchange.com/questions/40624/use-of-go-in-passive-form/40780#40780
Answer: Not quite sure what you are asking. If it is whether your example is grammatically correct, then I would say it is. If I were writing it I might prefer to use "to" rather than "through", because generally someone "goes to a lot of trouble".
If you wanted advice on whether to use such a sentence, then as a matter of personal preference I would say it is bad style. As @user159691 has pointed out the sentence is not easy to read. What is the main point being made? The passive voice has its place, of course.   In your example, its use suggests that the main point is that trouble had been taken (or gone through or gone to) and that the issue of who had taken that trouble was not important. That seems unlikely to be true. For the same reason official language favours the passive voice, because officials seem to like to be vague about exactly who was responsible for things. (I know; I was one myself.)
Answer: To go through means "to endure, to suffer, to experience".
The collocation go through (a lot of) trouble is normally used in contexts where the speaker is emphasizing  someone's efforts:

Your uncle went through a lot of trouble to get you that interview.
  You shouldn't treat it so casually.

and so it is a little peculiar to find it used in a passive construction which removes that someone from the picture:

A lot of trouble was gone through to get you that interview.

It's grammatical, and it's not impossible that leaving uncle out of the picture is deliberate. It could make the recrimination either milder or more stinging. The effect of the passive construction would depend on the people involved.
P.S. There is also the collocation go to (a lot of) trouble which means essentially the same thing.


Am I allowed to use other q and a sites?

Question: I'm just curious if like, for example I was trying to answer a story-id question, am I allowed to use other q and a cites to find an answer to the question I'm trying to answer.
Answer: Yes.
All content posted on Stack Exchange is licensed under the Creative Commons Share Alike 3.0 license, which means that you can use the content with proper attribution.
So as long as you're not just word-for-word copy-pasting questions to somewhere else, that's fine.
Aside from that, it's perfectly acceptable and even encouraged to use other sites as sources. Just keep in mind the guidelines for referencing, and you should be fine with getting an answer elsewhere and then using that as a source for an answer here. Make sure that you're not just reposting what they wrote here; elaborate, explain more, add sources, include your own work...
As an aside - linking people here from other sites, especially if they could answer a question, is a great way to drive traffic, and you can even win badges for driving people here using the "share" link on the bottom of every post (in the format https://literature.stackexchange.com/[a or q]/[post id][your user id]). Just make sure that the people you're driving here are at least nominally aware of how the site is different from standard internet forums - linking them to the tour or How to Answer can save a lot of time and aggravation on both ends.
Comment: so, i've tried to follow all these guidelines, but just for confirmation is this all right?https://www.reddit.com/r/whatsthatbook/comments/aa2ats/short_story_about_a_man_condemned_to_death/
Comment: Looks okay to me.


Dead hero IS or WAS inspiring?

Question: My son is writing an essay about a dead hero. Most of the verb tense he used is in the PAST, as in, "He was a clever hero." To be consistent, he wrote, "He was an inspiring hero." However, it got me thinking if it would be better to say, "He is an inspiring hero," because he still continues to inspire others even after his death.
Answer:
"He is an inspiring hero," because he still continues to inspire
  others even after his death.

you are both correct grammatically, you both mean different stuff.
you son's version:

He inspired people when he was alive, it's unclear if he still inspires people

your version:

He inspires people in the present, it's unclear if people were inspired by him when he was alive

they are both correct. let me throw another one in:

He has been an inspiring hero.*

this one means:

In his lifetime, and afterward he is an inspiring hero, up until now.

all of them are correct, the question is - what do you want to convey?
*in real speech, "he has" is almost always contracted to "he's"

Dead hero IS or WAS inspiring?


Changing network type from Unidentified network to Private network on an OpenVPN connection

Question: Is it possible to change the connection type in Windows 7? I have a OpenVPN connection which is identified as "unidentified network" and I do not want to apply certain rules to all unidentified networks in the firewall.
How does one conquer this?
Answer: You have to add default gateway for OpenVPN network interface.
The way I found is adding route to target address 0.0.0.0 via network interface used OpenVPN.
In this example I have a computer with the physical interface with IP addres 10.20.20.20 in network 10.20.20.0/24 and the OpenVPN TAP interface with IP address 10.1.1.10/24 in network 10.1.1.0/24 (IP address of server on VPN network is 10.1.1.1).
1) Find out your network interfaces and information about current route to 0.0.0.0:
C:\>route print -4
===========================================================================
Interface List
 15...00 ff 6c 3f 5b 0c ......TAP-Win32 Adapter V9
 11...00 0e 0c d9 b5 c8 ......Intel(R) PRO/1000 GT Desktop Adapter
===========================================================================

IPv4 Route table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway        Interface Metric
          0.0.0.0          0.0.0.0       10.20.20.1      10.20.20.20     10
       10.20.20.0    255.255.255.0         On-link       10.20.20.20    266
...

At now we know that your OpenVPN network interface number is 15. Another important information is the metric of current route to 0.0.0.0. New route to 0.0.0.0 for OpenVPN network should have higher metric value than current to avoid redirecting whole network traffic to your OpenVPN connection instead of physical network (in case of two routes with the same routes, the route with lower metric will be chosen).
2) Add route to 0.0.0.0 via OpenVPN interface:
route -p add 0.0.0.0 mask 0.0.0.0 10.1.1.1 metric 50 if 15

This command adds route to 0.0.0.0 via interface 15 with metric at least 50 and gateway 10.1.1.1. Replace the gateway with your own (IP address of server on VPN network). And of course, replace the interface number with your own.
The -p argument adds route as permanent so it will be preserved after system reboot.
3) (Re)connect to VPN server and look into route table again:
C:\>route print -4
...
Active Routes:
Network Destination        Netmask          Gateway        Interface Metric
          0.0.0.0          0.0.0.0       10.20.20.1      10.20.20.20     10
          0.0.0.0          0.0.0.0         10.1.1.1        10.1.1.10     80
...

And network is now identified in Network and Sharing Center so the 'Set a location...' window should appear ;-)
Comment: Be careful, keep your metric greater than your normal interface metrics! Otherwise you'll knock your host offline like I just did.
Comment: This is the correct answer.
Answer: I dont' know why the above solutions are so complicated, e.g. using
route add -p commands

or even adding to the OpenVPN server.conf file
route 0.0.0.0 vpn_subnet_mask default_gateway

The error could simply be solved by going to:
Control Panel\Network and Internet\Network Connections

(1)Right-click OpenVPN tun/tap interface and select Status > select Details > take note of the IPv4 DHCP Server entry. you would
need to fill this in as the default gateway in (2).
(2)Right-click OpenVPN tun/tap interface and select Properties > open TCP/IPv4 properties > click Advanced. under default gateways, click add and type in
exact same entry as used as DHCP server, metric 'automatic'. Now wait for the adapter to
magically appear as private.
What you just did the exact same thing as the above two solutions - adding persistent routes - but this is even better - it survives restarts since it's configured in Windows. You can actually check in cmd by typing 'route print' and you'll see 1 entry added in the routing table, as well as 1 entry under persistent routes. If the metric of the new route is smaller than that of your physical adapter, redo (2) and change the metric from 'automatic' to a value higher than the physical adapter.
If your gateway (openvpn server IP) is static, adding it (2) does the job.
Answer: Look at "TAP driver / identified vs unidentified networks"  or "Vista and Windows Server 2008 - Unidentified network"
Comment: This did not allow me to set the location.  It simply says Enabled instead of Unidentified Network.  If you want to set a location type, see [this answer](http://superuser.com/a/218509/85708).
Answer: I think the absolutely simplest and best way to solve this is to do this:

Open your OpenVPN configuration file.
Add this line: route 0.0.0.0 0.0.0.0 vpn_gateway 50 (don't change vpn_gateway, it's an environment variable) and save.
Connect VPN
If needed continue to step 5 and 6.
Open run (Win+R) and type secpol.msc go to 'Network List Manager Policies'
Right click on on your VPN network, and properties->Network location. Select Private Network.

This way you won't have to care about your VPN gateway IP, and also works with dynamic VPN gateways.
Comment: You can also set the metric (50) higher on a split-tunnel VPN to fix this without breaking the split.  500 worked for me
Answer: This works nicely with some VPN connections, but lets say the default gateway for your VPN constantly changes.  That means, every time you reset the computer, you have to use the 'route add' command over and over again. That is unacceptable.
While researching an issue with VMware in windows 7, I came across a registry dword called *NdisDeviceType.  What this does is, it tells windows not to try to identify a specific virtual network adapter.  All you have to do is go in the registry and navigate to HKLM\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}.
Once there, look in the keys for a string called DriverDesc with a value of 'Tap-win'.  This is the key that deals with the virtual adapter that OpenVPN uses.  Next create a dword called *NdisDeviceType and assign it a value of 1.
Finally restart your computer.  Now you shouldn't see an unidentified network.  Please remember to backup your registry before you attempt this modification.  If you are using OpenVPN, and you don't feel comfortable doing this, you can download a script that will do this for you.
Answer: This works, but it is better if you take it one step further by changing the IP settings for the TAP adapter manually.  Use ipconfig to figure out the proper settings and use the gateway for the DNS server.
Update:  Ignore this step - if you do it your IP address won't be masked.  I don't know why that is but I have done everything I can think of to reverse it, but the only way is to undo what I did in this step and reboot the computer.
Update:  A problem I have with this is that I configured Windows 7 to start the connection when I boot Windows. Sometimes when I reboot or shutdown the computer, the network would go back to unknown.  The route would still be in the table.  A workaround to this was to modify my configuration file for the VPN client I connect to.  The command I added was:
#Dummy default gateway to work around Windows 'unidentified network'/'unknown network' (put a "#" in front of this)
route-metric 30
route 0.0.0.0 0.0.0.0 10.0.0.1.

Metric is retrieved by reading the route table that is displayed with:
route print -4

10.0.0.1 is the gateway that the VPN connects to. For example when I'm connected to the VPN, my route table looks something like this:
-------------------------------------------------------------------------
IPv4 Route Table
-------------------------------------------------------------------------
Active Routes:
Network Destination      Netmask        Gateway      Interface    Metric
          0.0.0.0        0.0.0.0    192.168.0.1  192.168.0.100        25
          0.0.0.0      126.96.36.199       10.0.0.1     10.0.7.102        30

The first entry is the route to my router.  The second one is the VPN Connection.  Now when I modify the VPN connection file (vpn.ovpn in my case) I use the network destination and make the netmask 0.0.0.0, and use 10.0.0.1 as my gateway.  I then note that the metric is set to 30 and set it to 30 in the config file.
Answer: If you have completed the addition of the default gateway (through commands or the Windows GUI), you may still need a way to indicate to Windows that you want apply the designation of Private or Domain to the network. Perhaps you accidentally labelled the network as Public already or for whatever reason never had the chance to choose with the "Set a location..." prompt. I ran into this scenario on Windows 10.
To set this via the Registry, navigate to the Network Profiles key, at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NetworkList\Profiles.  From here, the Profiles key contains a list of keys with GUIDs which correspond to all of the networks your computer has saved. You can look through these GUID keys and find your network by matching the ProfileName value in the key.  Once you find the correct network in the Profiles key, you want to alter the Category value for the network key.
A value in the Category value of 0 indicates a Public network. You can change this value to 1 to label the network as Private or 2 to designate the network as a Domain network. To apply this change, you may need to reinitialize the network connection.
Comment: If we need to delete the images because of the "TenForums.com" watermark, feel free to edit my question or let me know.
Answer: All the solutions mentioned above are actually just workarounds but, every commodity / product has its own buyers as the say.
The simplest is to delete the unknown 0.0.0.0 route created and then everything should get back in place. Just run cmd.exe (as admin) from your command line and then type route delete 0.0.0.0 That's it.
I don't think that registering junk routes and other garbage or just doing it vice versa and making an elephant out of the fly is the one of the greatest ideas... Good luck!
Answer: On my Windows 7 machine, the "Unidentified Network" was the symptom of the OpenVPN problem, not the cause.  In my case, the fix is to start the OpenVPN client GUI using Administrator Privileges.
Answer: one thing that worked for me after trying some of the methods above with mixed success was going into the adapter settings for the TAP NordVPN Windows adapter V9 > Properties > Configure > Advanced > Non Admin Access > Not Allowed.  Adapter disconnected as public and reconnected as private.  I think this worked in conjunction with droidgren's solution.
Answer: The simplest way I have recently found is to change it through the elevated powershell.
Run "Get-NetConnectionProfile" to list all the network connections, and then run "Set-NetConnectionProfile -InterfaceIndex  -NetworkCategory Private"
Answer: There is so many answers, but using secpol.msc only trick like suggested by @droidgren is the best and safest way. Adding broken routes with high metrics as a workaround is really sick, even if it works
I tested on Windows 10 and latest OpenVPN Connect client. The dynamically assigned TAP network can properly be set to private and the setting is remembered later
Also, this far better than other threads suggesting to keep the VPN network as public and set the Open Wifi adapter to private to setup firewall rules blocking all non VPN internet traffic. Clearly, VPN adapter must be set to private and any open Wifi or unsecure adapter to public


iPad photos missing from folder view in Windows

Question: I have my iPad plugged into my Windows 7 computer, and I can see the Internal Storage of the iPad but most of the photos are missing. I have many different albums on the iPad and none of them are visible inside explorer view. How can I get these photos off my iPad?
Answer: You can only access photos in your camera roll via USB, I suspect you added those other albums via iTunes (as opposed to created them on you device with iOS 5). There is no official way to get those photos off your device.

You can try to find an app that can access your photos and save them to your camera roll (e.g. Photoshop Express, free). This might be a lot a work depending on how many photos you need to copy.
You could use Dropbox to upload your photos to their servers and download them on your PC. You'll need an dropbox account, but up to 2GB is free. Dropbox allows you to select multiple photos to upload at once.
If your device is jailbroken you can get access to the filesystem and copy your phones that way.


What phenomenon causes "lunar waves"?

Question: In multiple video clips of the moon but also one of Jupiter, some kind of waves can be observed. Is this just the effect of the object moving behind layers of different refractive indexes (similar to what we observe at sunset) or is there a wave propagating through the atmosphere?
https://m.youtube.com/watch?v=xUGxysKSGEM
https://m.youtube.com/watch?v=EMSkd4Xhp0g
There is an answer on Quora, but I would love to see a more detailed answer, why we can see exactly these two rather sharp lines moving.
Comment: I'm voting to close this question as off-topic because it asks about youtube videos of pseudoscience and fakery, not about astronomy.
Comment: To me atmospheric distorsion seems the most likely cause, so I would love to see a model explaining it, either via theoretical physics or with a sketch. I am just curious which conditions could lead to such a clear "line". Or get another explanation for the phenomenon, if there are clues for that.
Comment: @Chappo [Are questions about phenomenon only observed in certain YouTube channels on-topic?](https://astronomy.meta.stackexchange.com/q/499/7982)
Comment: @uhoh This is pretty much how science works as long as you are open to admit it when your theory fails. A scientist observes something and tries to build a model that describes it and similar effects in general. And for that you have to choose a starting point from which you start checking all possible explanations.
Comment: @uhoh aren't you conflating two distinct issues? Yes, the first video is a compilation by "crrow" who is an astrologer (boo, hiss), but are you saying that every one of his 10 videos is a fake, and the other unrelated video is also a fake? Or are you just reacting (negatively) to the messenger rather than the message? If you are certain all the videos are faked, please explain what brings you to that conclusion...
Comment: @uhoh On the other hand, if there's a possibility that at least some of the videos are genuine, then the question is very much on-topic as it's about an anomaly in astronomical observation. The Quora post suggests several explanations, but we can rule out "atmospheric tides", "atmospheric diffraction" and "an effect of Astronomical seeing" (all proposed by actual astronomers), since these don't match the slow symmetrical pattern. Sticking strictly to **science**, that just leaves either some other atmospheric anomaly, or an equipment or recording issue. I'm interested in hearing from others...
Comment: @Chappo I'm saying only exactly what I've said in my 21 word comment. (plus those twelve words (plus those four (plus those three (plus those three (plus...
Comment: @Chappo then you can ask the moderators to move it to [Skeptics SE](https://skeptics.stackexchange.com/) where that kind of "it might not be wrong" speculation is well-suited.
Comment: @uhoh I do understand that even mentioning astrology makes astronomers foam at the mouth, hence the extraordinary level of derision in the other answer and comments. But I suggest Florin Andrei's calmer, more *scientific* approach [see his comment](https://astronomy.stackexchange.com/questions/27597/what-phenomenon-causes-lunar-waves?noredirect=1#comment54885_27608) is preferable, and I note your own dismissal of far-fetched ideas like blowing a fan.
Comment: @Chappo it's the monetization of the far-fetched ideas in YouTube along with a lack of peer-reviewed publication and independent scientific scrutiny that leads me to call it "pseudoscience and fakery". If this was anything other than a hoax, thousands of people would see it in binoculars and telescopes, not just in money-making YouTube videos. This is Astronomy SE, a site about a field of science.
Comment: I'm voting to leave this question open. It's without doubt *on topic* (excluding any conspiracy theory that all 11 video clips are fake), and there's no risk that a visitor to this page could possibly think there's any support for astrological or other occult or non-scientific views on this. I don't believe in closing a question just because it's awkward or asked by someone we don't like or doesn't (yet) have a good explanation.
Comment: Voting to close as 'unclear what you're asking' for two reasons: (1) The phenomenon in the Jupiter movie looks different from the moon movies (2) We're going to need the *original footage* from the fragments in the first movie because its editor is an unreliable source. It may be two interesting questions if rephrased. And yes, probably just some atmospheric phenomena or instrument artifacts.
Comment: @Gimli that's the opposite of how science works (choosing a favorite explanation, then try to find someone to make a model to justify your choice).
Comment: @Gimli no, this is not pretty much how science works. Where is the *Materials and Methods* section? Where is the peer review? And here *there is no theory*, just a monologue complaining that "the observatories" don't take the owner of the monetized YouTube channel seriously. Click away! But we shouldn't be using Astronomy Stack Exchange to advertise and drive traffic there, leaving comments that it's "pretty much how science works".
Answer: Video astronomy requires much more equipment than traditional eyepiece viewing. It helps to understand what is going on between the camera lens and the video screen.
Most important is the conversion of the cameras analog signal to the computer digital format. This is usually done with a frame grabber and its associated drivers. The cameras typically have 700 ish lines of resolution which are usually translated into 640 by 480 digital signal. The camera analog signal is 60 cycle interlaced. The computer display frequency is whatever the PC is set to. I'll let the Math people tell us how the drivers fit all those numbers together and make a nice picture. I think the answer is PI or at least within a decimal place or two. The numbers get rounded and every once in a while the computer screen hiccups. National Enquirer sort of news.
The frame grabbers come in a wide range of cost and reliability. There's no rhyme or reason to their reliability. They depend on the computers operating system which is not identical on every computer. The frame grabber and driver will work well on one PC but not another similarly equipped PC.
Typically the astro video cameras two output connectors, a coax and an S-Video. The person making the video could have proven the "Waves" were and artifact of the PC by simply connecting one of the cameras outputs to an analog video screen, a television with a composite input for example and the other output to the computers frame grabber. Provided the camera and analog video are functioning properly he could have shown us a rock steady image on the analog screen and the waves on the Computer screen. With a little skill he could have shown us an alien or two surfing on the waves.
Smoke, mirrors and snake oil. Suckers are said to be born at the rate of one per minute. I have a feeling the con artist birth rate is up there as well.
It is a bit of a shame, Video or near live viewing as many of us call it, is gaining in popularity. Having someone use what is not unusual for a Video astronomer to see just for a bit of sensationalism serves no useful purpose.
Another point to edit in. The uTube is a video of a video. The image we see is taken by a second video cameras pointed at a video image being displayed on a computer screen. Crunch the computer screen frequency and resolution with the frequency and resolution of the second camera. You end up with images of airplane propellers that appear to stand still or move very slowly. I wonder how much adverting revenue that sort of video would bring into uTube.
Comment: I would be happy to upvote this answer if you [edit]ed it to remove the subjective opinion (especially paras 5 & 6, and your last sentence), which detracts from the value of an otherwise good *science-based* answer.
Comment: you may be interested in contributing to [Are questions about phenomenon only observed in certain YouTube channels on-topic?](https://astronomy.meta.stackexchange.com/q/499/7982)
Answer: The guy's a wack job.   It's atmospheric turbulence that just happens to have a long regular structure in one direction.   Heck, he might even be deliberately blowing a fan across his telescope to create those patterns.  Ignore him.
Comment: `-1` Debunking pseudo science looses credibility with wrong sentences like "...he might even be deliberately blowing a fan across his telescope to create those patterns. " That would not do this.
Comment: "...blowing a fan across his telescope..." can not "...create those patterns..." That's wrong in several ways.
Comment: It's clearly not a sonic boom, or else it would be 200 km away or something like that. It's some other kind of change in air density. Maybe thermal. Maybe wind-like. But I have a lot of trouble imagining some way that would make such a neat and regular wavefront via mechanisms other than a shock wave. Convection tends to be messy and turbulent. Maybe some kind of shear between layers of air at different temperatures? It would help to know the Moon's elevation at the moment of observation.
Comment: Anything immediately in front of the telescope will be completely out of focus. Patterns in the video are relatively sharp which means *if they were to be real* they would be caused by things hundreds of meters beyond the end of the telescope. Refraction patterns shown *if they were to be real* result from optical path differences larger than you could make with a fan. A fan pushes air around, but in free space it does not have a significant impact on density and therefore index of refraction.
Comment: The comments on that video are hilarious. Or sad - depending on how you consider the whole thing.
Comment: @uhoh ORLY?  There are plenty of examples of crackpot "scientists" who fake their data - sometimes knowingly, sometimes via unconscious bias or "fudging" steps.
Comment: @uhoh, I spent 20 years designing, building, and testing AO systems. I know what patterns can be generated with aerodynamic sources.
Answer: Thus far there has been no solid explanation.
However, the person who discovered it, YouTube user Crrow777 has a video which explain his observations, and handily debunk Carl Witthoft's explanation of it being atmospheric turbulence.
https://www.youtube.com/watch?v=xUGxysKSGEM
The most obvious of which being that the distortion does not extent beyond the boundary presented by the structure of the moon in the image, even while the camera is moving around.
Comment: Please. This is crackpottery. Not even worth debunking.
Comment: *the person who discovered it, YouTube user Crrow777* The movies are shot by other people.
Comment: Be nice to see these wave vids paired to detailed atmospheric pressure, frontal systems and jet stream movements at the time they were taken. https://www.wpc.ncep.noaa.gov/sfc/lrgnamsfcwbg.gif Airlines likely have a good detailed jet stream mapping somewhere.

What phenomenon causes "lunar waves"?


Can I say "You will start all again"

Question: Is it right to say "You will start all again"?
I know that 'You will start all over again' is right and I think I can also say 'You will start it all again'.
But can I say 'You will start all again'?
Comment: Instead of "You will start all again" I would say "You will start *everything* again".
Answer: Not really.

You will start all over again

sounds the most natural, although I've never heard it said in that way. Normally, one would say:

You have to start over

without any again. However, the again isn't wrong technically, it just sounds wrong to me.
The third sentence:

You will start it all again

sounds like you are telling somebody that they have to, that they will, without telling them why.

You will start all again

isn't right, you need to say what they are starting all over again, for example:

You will start it all again

or

You will start the activity all again

That also sounds like a firm instruction, as if the person has refused before (I'm reading it with emphasis like this: "You will start all again"), which may be what you want, but normally it would sound more natural to say:

Start it all again

Do you have any context? If you provide that with an edit to your question it would be easier to say what you need.

Can I say "You will start all again"


Isn't it too much having 5 times a week soccer trainings?

Question: I am not against soccer, but my son is 9 and still doesn't know what is right for him.
My husband completely supports him. But I believe so much soccer could influence the child's mentality and to reflect his results in school.
Answer: Many children who focus on a particular sport may do this many training sessions a week, or more. When I was competing for my county in swimming I used to train up to 8 or 10 times a week, and my kids train more than 5 times a week in gymnastics and swimming. They still score very highly academically, and I certainly got into a good university on my academic record.
The important thing is to balance their sport with academic learning - they are both good for you. As long as your child can get the academic results they need, taking part in a sport is going to keep them healthy.
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](http://chat.stackexchange.com/rooms/37836/discussion-on-answer-by-rory-alsop-isnt-it-too-much-having-5-times-a-week-socce).
Answer: The American Association of Pediatrics have a couple of reports which are worth reading on the subject of children's sports/training.  None of them specifically cover academic achievement but look at sports from a health perspective.

Overuse Injuries, Overtraining, and Burnout in Child and Adolescent Athletes
Intensive Training and Sports Specialization in Young Athletes

The articles concede there is limited research on the subject of children's sport but some of the most relevant parts say.

Those who participate in a variety of sports and specialize only after reaching the age of puberty tend to be more consistent performers, have fewer injuries, and adhere to sports play longer than those who specialize early.

Without specific studies on academic performance, they do make some notes on psychosocial development.

Anecdotal reports suggest risks of "burnout" from physical and emotional stress, missed social and educational opportunities, and disruptions of family life.

They also include some guidelines on the amount of activity to help prevent overtraining/burnout:

Keep workouts interesting, with age-appropriate games and training, to keep practice fun.

Take time off from organized or structured sports participation 1 to 2 days per week to allow the body to rest or participate in other activities.

Permit longer scheduled breaks from training and competition every 2 to 3 months while focusing on other activities and cross-training to prevent loss of skill or level of conditioning.

Focus on wellness and teaching athletes to be in tune with their bodies for cues to slow down or alter their training methods.

US Youth Soccer offer some things to look out for such as:-

Slower times in distance sports such as running, cycling, and swimming
Deterioration in execution of sports plays or routines such as those performed in figure skating and gymnastics
Decreased ability to achieve training goals
Lack of motivation to practice
Getting tired easily
Irritability and unwillingness to cooperate with teammates

Unfortunately, the tendency when a parent or coach is confronted with signs of overtraining is to push the child harder. But if overtraining is the culprit, any increase in training will only worsen the situation.

TL;DR  There isn't any evidence on academic achievement in relation to sports and it's really up to you to look out for the signs of when it's too much.  Try to encourage your child to take up a range of physically different sports/activities and watch for signs of "burnout".
Answer: I think it's good for your kid to learn a strong work ethic and teamwork early on. Emphasize the importance of keeping his grade up and in addition to his soccer. A lot of my high achieving high school students also play sports.
Personally, I always wanted to play soccer as a kid about your son's age, but my mother forbade it and told me to focus on my studies. It's always been a big regret of mine.
Answer: It really depends how passionate your child is about their hobby.
My two daughters 6 and 12 LOVE dance. They both dance 3 hours after school everyday, and 5 hours on Saturday. It's a lot but it's what they want to do. They still manage to do all their school work have dinner and get to bed for 8:15.
If your son finds its too much he will let you know, my 6 year old had said to me before can I have a week off dance, so they will let you know if it becomes too much


Is it possible that Planet 9 was thrown out of the Solar System?

Question: Is it possible that this planet changed other planet orbits (from which we assume that it exists) but then was thrown out of the Solar System in past when Sun was close to some other star? And it doesn't exist in our system anymore and we can't find it because of it.
Comment: There is almost no difference at all between very far out and ejected. Indeed the problem would be to fine tune a mechanism that just avoided ejection.
Comment: @ProfRob Nope. That question about moving Planet 9 from close to sun to far to sun. My question: "Is it possible that Planet 9 not exist anymore in Solar System?"
Comment: @Robotex and did you read the answer? Where's the significant difference to you between "far out and very loosely bound" and "ejected"?
Comment: @ProfRob So, we can never to find it bacause it can be ejected, right?
Answer: By definition Planet 9 is in the Solar System. Planet 9 is a hypothetical body, and we suspect that it might exist because of the motion of other bodies in the Solar System.
If a planet used to be in the Solar System but then got ejected, then that planet will no longer interact with the other objects in the Solar System. So it won't explain what we see happening in the Solar System.
It is not impossible that other planets existed in the Solar System and got ejected, but those hypothetical planets are different from the hypothetical object that is generally called "Planet 9". If it's not gravitationally bound, then it's not planet 9.
Comment: The ejection of another planet from the Solar System almost certainly would have had consequences for the present-day solar system configuration. Planet 9 could refer to an ejected planet.
Comment: "but then got ejected, then that planet will no longer interact with the other objects in the Solar System. So it won't explain what we see happening in the Solar System." -- but we can see the result of interactions in past
Comment: @Robotex "Planet 9" is the name we give to a hypothetical body that might explain a given set of things we observe in our solar system. If an object doesn't explain these things, then it is not "Planet 9". Other hypothetical bodies have been given other names.
Comment: @usernumber I mean that that object can explain these thing but not exist anymore. Imagine, you walked on sand on beach and then go out, but you steps still on the sand
Comment: @Robotex We're talking about dynamical effects here. If the orbit of a planet isn't explained by general relativity, that can mean one of two things: either there is something that is *still* tugging at it (so not a body that was ejected), or we need a new model to describe gravity (so not a body at all).


Do I need to remove old adhesive residue before installing new self-adhesive flooring?

Question: I have an old peel and stick floor in my kitchen that's is getting replaced. I'm putting down a new peel and stick floor. I'm removing the old one because it's curling and lifting from age. The subfloor has the sticky residue in it. Do I need to remove the adhesive or can I lay the floor right on top?
Answer: Check the "surface prep" instructions as it will likely instruct you to remove all previous residue, grease, dust, etc... or else they won't warrant their product.
FYI, removing all of the residue is damn near impossible as you are finding out and if you lay down new peel-n-stick then take a wild guess at what will happen to your new flooring in a few years.
I would probably choose to lay down the thinnest underlayment I can find such as 1/4 inch common plywood so that the project doesn't go to sh1t after a few years.
Answer: First off, check with the manufacturers of the tile you're putting down on surface preparation. In my experience, glues and adhesives don't stick well to old glues and adhesives or to the residue they leave. You should clean the surface with an adhesive remover like Goof Off. You can get it at many home stores. As always, read and follow the directions. Good luck.
Answer: I have put down peel n' stick flooring after removing an older peel n' stick floor. You need to lay down a new 1/4" layer on top of the old floor. Yes the new floor would stick to the older sub-floor/glue, however, you'll find edges and corners that just won't stay stuck down. With a new 1/4" floor you'll set. Just pull out the baseboard shoe moulding and reinstall when complete.


WD My Passport detected but not assigned a drive letter

Question: I have a WD My Passport external drive which used to work fine on my Win7 x64 box until recently. Since the past few days, windows would not detect my external drive. However, Storage under disk management lists my external drive(which means windows can see my drive) but without a drive letter. I am not able to assign a drive letter(the option is grayed out). I installed EASUS Partition Manager which allows me to assign a drive letter, but fails to do so when I apply to save changes. What do i do to assign a drive letter to the drive or make windows to detect it as of old?
The external drive works well on Win7 x32(dual boot, same system) and win7 x64 on another box.
Update: cant comment from Opera Mini 6
@zeke the drive works absolutely fine on other Win7 boxes and on the dual boot win7 on the same system.
Comment: Can I assume that there is no problem with the file system on the disk? And that you can mount this drive other places and are able to ready it? Mounting a foreign file system (such as might be used for a Mac or for Linux) will result in the hardware being recognized but no drive letter. But I've had situations with an NTFS file system not cleanly unmounted elsewhere needed attention if I try to mount it under Win 7.
Comment: just curious, if you go to device manager, right click the drive, do properties, go to volumes tab... click populate... does it fill in the blanks and/or give it a letter?
Comment: Can I assume that you haven't run out of drive letters? (Sounds crazy, but I have... And, sadly, it doesn't roll over to AA:, AB:..)
Comment: @skub I am at J.Still have a long way to go.
Comment: @CreeDorofl I got the Disk Management Console view is not up-to-date error, however I've solved the problem
Answer: I had already tried uninstalling the WD drive and removing the drivers from Device Manager, however, reattaching the drive resulted in the drive being installed but not displayed.
Then I noticed an entry in Device Manager>Storage Devices> called "Unknown Device". The device did not have an exclamatory sign or cross sign to indicate problems with the device. I uninstalled it, uninstalled the WD SES entry from Device Manager and rescanned for hardware changes. Windows detected my drive and Autoplay popped up prompting to play videos or open folder to view the drive.
The Device Manager does not have the Unknown device listed now.
I also installed USBDLM, which showed a balloon tip telling me that the drive had been assigned the letter J. I don't think using USBDLM was necessary in this case, but I haven't verified otherwise.


Simple dumb image viewer, with CLI access

Question: I am looking for a simple, dumb image viewing program, something that I can fire up from the command line.  Ideally this would be xv (is this available for Ubuntu 14.04?).  I just need something that lets me look at files in /usr/share/icons/ etc.  An important (necessary!) feature: it needs to work from the command line.  I am sshing into the Ubuntu machine (from a CentOS machine, but that is neither here nor there) -- I am NOT on the Ubuntu machine's console.
Comment: Why can't you use X Forwarding and the default image viewer (`eog`)?
Comment: Bad luck, I suppose. I tried `apropos viewer`, and `eog` was the second term for me. (`image` would be just too broad, I think).
Comment: Mostly because I did not know about eog.  I am not vastly familar with Ubuntu or what packages are installed by default. Doing an 'apropos image' did not turn up anything useful -- I'm guessing that eog probably does not have a useful man page -- man pages are pretty much going out of style, so tools like apropos at the command line are no longer as useful as they once were.  (Remember I am not doing this at the Ubuntu machine's console, so I don't have access to the GUI search thingy.
Answer: Feh is a fast, lightweight image viewer. You can install feh from the default Ubuntu repositories.
It is commandline-driven and supports multiple images through slideshows, thumbnail browsing or multiple windows, and montages or index prints (using TrueType fonts to display file info). Advanced features include fast dynamic zooming, progressive  loading, loading via HTTP (with reload support for watching webcams), recursive file opening (slideshow of a directory hierarchy), and mouse wheel/keyboard control.
Answer: A very lightweight image viewer comes with the xloadimage  package to display an image in a window, provided an X-Server is running.
There are many options we can control from the command line (e. -zoom, -fit, -fullscreen etc.). Supported image formats for viewing are niff, sunraster, gif, jpeg, tiff, png, fbm, cmuraster, bpm, faces, rle, xwd, vff, mcidas, vicar, ocx, gem, macpaint, xpm, and xbm.
To view an image:
xview path/to/image

There are no further mouse controls other than closing with a right click.


Fusion Tables Filtering/query

Question: I'm using greet searchable map template with fusion tables by Derek Eder. I can connect the script to my fusion table and showing my projects on map successfully but when I'm trying to filter from a type column using checkboxs, the data on map not changing. Can any one help me?
Here's my website: http://bu.sixtag.com and if you look at the resource there's a js file name maps_lib.js that there's my setting.
Answer: I just took a quick look at your code to see if I could offer any assistance as I too am working through some of Derek Eder's wonderful fusion table searchable template examples. What I did see was errors in your code, specifically
<code>Invalid row index 4. Should be in the range [0-3].
</code>
If I were you I would make a point of familiarizing myself with console.log() as it's really useful to help self-diagnose your code first before posting up help etc.
Good luck!!

Fusion Tables Filtering/query


What are the opensource alternatives for MS Project in order to manage Project management?

Question: Can anybody suggest some  project management open source alternative software for MS PROJECT?
Answer: GanttProject Open Source by Dmitry Barashev, Alexandre Thomas | Mac, Windows, Linux
GanttProject is a cross-platform desktop tool for project scheduling and management. It runs on Windows, Linux and MacOSX, it is free and its code is opensource.
ProjectLibre Open Source | Mac, Windows, Linux
ProjectLibre is a Java-based project management solution that gives Microsoft Project a run for its money. Offering a UI similar enough to ease the transition from Microsoft's market leader.
GNOME Planner Open Source by Richard Hult and Mikael Hallendal, | Windows, Linux
Planner is the GNOME project management tool. Its goal is to be an easy-to-use no-nonsense cross-platform project management application.
Calligra Plan Open Source by Calligra Suite | Linux
Calligra Plan (formerly KPlato) is a project management application. It is intended for managing moderately large projects with multiple resources.
2-Plan Free | Mac, Windows, Linux
2-plan Project Management Systems offers three PM tools: a free desktop system, an open-source software for multiple projects and teams, and a scrum board.
Source:
http://alternativeto.net/
Answer: You can also try RationalPlan Single. It is not open source but it is free for Linux users.
Answer: RationalPlan is good and the single version is free on Linux. Gantter also hasn't been mentioned here and is fully integrated with Google Drive. If you scroll down this article, there are some good open source alternatives which work on both Linux and Mac:
Source: https://machow2.com/best-alternatives-microsoft-project-mac/
Comment: Gantter not opening an mmp file in my case...


Why cant we use 64 bit OS on a 32 bit CPU?

Question: Why can't a 64-bit OS run on a 32-bit CPU, but a 32-bit OS works on a 64 bit CPU?
Comment: Why can't you run software for CPU type "A" on a CPU of type "B"? Because A != B.
Comment: Of course you can, all you have to do is remove the 32-bit CPU and put a 64-bit CPU in.
Comment: simple answer: Because it is a PITA. :)
Answer: I'm assuming we're talking about standard PCs here.
Most 64-bit processors - especially the ones from Intel and AMD - have the full 32-bit instruction set as well as the 64-bit extensions, so they can run 32-bit software.
32-bit processers don't have a 64-bit instruction set though. Many were made even before the 64-bit instruction set was defined, so it's not possible they could implement it correctly, even emulated. They just don't understand that language.
Comment: It all at the base level comes down to registers. 64 bit processors can move stuff 64 bits at a time. 32 bit processors don't have 64 bit registers.
Answer: 64 bit CPUs support any word length up to 64 bits, so in theory, any 8, 16, 32 or 64 bit OS will run on them. 32 bit CPUs don't support 64 bit word length, so only <=32 bit software (including 32 bit OSs) can be run on them.
Comment: Actually, this answer is at least somehow wrong on several levels. The main way that it's wrong is this -- typical 32-bit CPUs operate on 64-bit words just fine. The original Pentium 4 had plenty of instructions that operate on 64-bit words. It has little to do with the word length and everything to do with the instruction set.
Comment: +1: IMO, the only 'right' answer in this bunch. :)
Answer: Why can't you run Windows on your old Atari? Incompatible hardware and processors.
x86-64 should be considered completely different from x86 because it is vastly different from the kernel and machine code point of view. The only thing they really share in common is the bootstrapping code(from the 16bit startup, to get to 64bit you must [usually] go to 32bit first) and the 32-bit compatability mode and the common CPU extensions like SSE. Other than that, the processors are really completely different as to how applications are made in machine code.
Comment: You're vastly overstating the case here. At least 99% of the source code in Windows, not excepting the kernel mode components, is the same between the x86, x64, ia64, and ARM. And even in an x64 program, the x64 architecture is largely a superset of x86. e.g. if you want to copy EAX to EBX, that's MOV EBX EAX in both x86 and x64; even the machine coding of that instruction is the same between those two.
Comment: @JamieHanrahan maybe, except for stuff like PIC, anything involving pointers, etc etc... you can't compile a program for x86 and it's binary "just work" for x64, even if the machine code itself is similar, there are semantic differences
Comment: Actually, yes, you can do exactly that. You do that every time you run a 32-bit program on 64-bit Windows.
Answer: Its because the processor in the case of a 32bit machine cant handle 64bit processing, but a 64bit processor is more than capable of handling 32bits as it can deal with 64bits at a time.
Answer: A 64bit OS is programmed with 64bit registers in mind. A 32bit CPU only has 32bit registers.
There are lots of other reasons for this as well, besides just registers.
Answer: A 64 bit OS relies on processor features of a 64 bit processor.
You can't tell a 32 bit process to perform an operation on the 64 bit register if it doesn't exist.
Whereas 64 bit processors have everything the 32 bit one has, so it can be done.


Number of combinations of balls

Question: We have $M$ boxes $i\in\{1,\dots,M\}$ with each box containing $N$ balls of color $i$. Given $T<\min(M,N)$, how many ways can we choose $T$ balls such that atleast $2$ of them have same color and how many ways can we choose $T$ balls such that no $2$ of them have same color (same ball can be chosen more than once)? Can former be much smaller than latter?
Answer: The number of balls is irrelevant (if we have enough of them).
The first question can be reformulated as follows. Point at the boxes randomly. How many ways of pointing are there such that there is at least one box that you point at at least twice? So first you can choose one box that will be pointed at twice. There are $M$ such possibilities. By this, you have used up two possibilities of pointing. There are $T-2$ further opportunities to freely point at the $M$ boxes. The total is: $$MM^{T-2}=M^{T-1}.$$
In the second case you have to point at the boxes $T$ times such that no two boxes will be pointed at twice. First you can pick $M$ boxes then you can pick only $M-1$ boxes, and so on, finally the number of remaining possibilities is $M-T+1$. The total is this time $$M(M-1)(M-2)...(M-T+1).$$
The relationship between the results is not unique. For example if we have $5$ boxes and $3$ choices then $$5^2<5.4.3.$$ However, if we have $5$ boxes and $4$ choices then $$5^3>18.104.22.168.$$ If the number of boxes, $M$, is growing, and $T$ remains, say, $2$ then
$$\lim_{M\rightarrow\infty}\frac{M}{M(M-1)}=0.$$

Number of combinations of balls


How much medieval philosophy do I need to know to understand modern philosophy?

Question: I have read Plato's dialogues, Aristotles's "Nicomachean Ethics" and also Peter Adamson's two books about classical and hellenistic philosophies. Do I need to read primary texts of medieval philosophy or can I continue with Descartes?
Comment: How much history do you need to know, to understand now? Same lind of question. I'd rate Stoicism as important. But mostly medieval scholastic philosophy was Christian theology, so it depends if you are interested in that. Descartes & Hobbes onward, & you get on to themes of modern relevance, to science & society. I like Vervaeke's threading together of key moment in the history of philosophy, in [Awakening From The Meaning Crisis](https://youtube.com/playlist?list=PLND1JCRq8Vuh3f0P5qjrSdb5eC1ZfZwWJ) series.
Answer: Medieval philosophy deals with the relation between antique Greek philosophy and the Christian wordview. In short: The relation between revelation and reason.
These topics and a prototypic attempt to match both to understand our world can be found in the writing of Thomas Aquinas, e.g., in his textbook Summa Theologiae.
Medieval philosophy, named scholastic, develops or elaborates a series of technical metaphysical terms: Being, the term "good", ens realissimum, god, salvation, sin,  etc. which carry over to philosophers of the 17. century. Even Descartes, who makes a new start, uses some of these terms, often without further explanation.
Who has decided due to other reasons that the scholastic woldview and its ontology is outdated, can skip medieval philosophy on the first round. He/she can make a big jump and continue with Descartes and epistemology. In particular if one is interested in the new ideas introduced by Kant to epistemology, or even later during the philosophy of the 20th century due to the new approach of Karl Popper.
But in any case, I would come back later. And read some primary sources from medieval philosophy, e.g. the first quaestio with some of the first articulos from Aquina's Summa Theologiae.


Do I need Ex's Signature on Closing Documents if I have Quit Claim Deed?

Question: I was awarded my home in my divorce decree and I have an offer on it now. Do I need my ex's signature on any loan documents during the closing process if I have a Quit Claim Deed filed with the county?
Comment: How long has it been since the quit claim deed has been filed with the county?
Comment: @mhoran_psprep I'm actually going to file it today.
Answer: The issue is will the title insurance company issuing the title insurance policy for the lender and the title insurance policy for the borrower feel that what you have is sufficient. They will have to payout if later on your Ex-spouse claims that they are still an owner. Will they cover that risk?
When I bought a house about 20 years ago the person selling the house was asked by the insurance company to provide a freshly notarized quit claim deed from the ex-spouse, on top of the paperwork filed with the county. You might be asked to do the same thing.
If they won't sign, or they can't be located, it will depend on what other paperwork they will accept.


Are schools over protective?

Question: My school says that they can see their students history, but is it possible for them to do so even though you are using your own device?
Comment: Not sure how the title relates to the body
Comment: Hello, and welcome to the Information Security SE.  Your question is slightly vague.  If you can give us more information, we will be able to provide you with better answers.  For example, are you on their network?  Are you using only your own device, or the schools devices as wel?.  Are you referring specifically to browser history, or any other sort of information
Comment: sure, in some cases they can.
Comment: In almost all cases they can. They own the network, they only need to look at DNS traffic.
Comment: @ThoriumBR but tying DNS queries to specific students is not always straightforward
Comment: If you put together AD login time, DHCP logs and DNS, you know who accessed what. If you have an authenticated proxy, it's even easier.
Answer: TL;DR: yes, in some cases they can
I assume you are browsing the Internet on your own device connected to your school's Wi-Fi network, and that they didn't make you install any software on it or make you accept any SSL certificates (e.g. via Profiles on iOS).
Provided you only connect to websites protected by HTTPS (SSL/TLS), all they can see are the DNS requests from your device and a pretty precise estimate of how much data you are transferring, but not the names of the pages.
For example: imagine you are watching the YouTube video at https://www.youtube.com/watch?v=dQw4w9WgXcQ. They will be able to know that you are streaming content from youtube.com at a certain bitrate, but they won't be able to know what content exactly is being transferred (though they will be able to take a wild guess and say it's a video, since you are on YouTube).
However, when you are instead using a website that doesn't support HTTPS (i.e. you're at an address that starts in http:// instead of https://, using software such as WireShark they will be able to read data transfers in clear and see exactly what you are seeing!
Additionally, if you plan on using Torrent software (such as uTorrent, BitTorrent, qBitTorrent, Transmission or similar) or other P2P platforms (like Emule), the data you transfer will also most likely be not encrypted, so doing illegal torrents from school is not a great idea, not that it is in general. Most online games (albeit not Minecraft since version 1.7.x) will also not encrypt their connections.
Ways around these limits are:

Using VPNs (some are free, but the good ones are paid services)
Using something like Tor (not recommended due to the high connection latency and low bandwidth, as well as being blocked at most schools and workplaces)
Using a selfhosted encrypted network proxy at home (Squid is IMHO one of the best softwares to do this)
Not breaking school rules maybe (?) :D
Comment: You may want to add that they will be able to see the hostnames from SNI (although this data would likely match the data they could gain from DNS)

Are schools over protective?


What are the requirements to vote in the community moderator nomination?

Question: I can't vote in the community moderator nomination. In fact, I can't even see the arrows or current vote count for each of the candidates.
What are the requirements?
Answer: The election is currently in the nomination phase, so there isn't any voting to be done yet.
The primaries will be held in five days on 2011-11-04 and will require 150 reputation to vote in, followed by the final election period on 2011-11-18.
Comment: Cool! Thanks for the information.
Comment: +1, this is the correct answer as to what the requirements are.
Answer: It's currently just in the Nomination phase meaning people suggest themselves and explain why they will be good moderators.
Our votes will be accepted in the final phase (Election).
In the current phase of Nomination you can:

Add yourself as candidate.
See who else is nominee.
Post comments on existing candidates.
Comment: Ah ok, cool. Thanks for the quick answer! :)
Answer: During the nomination phase you don't vote for the candidates; the first thirty candidates, ordered by their reputation, pass to the primary phase.
In the next two phases ("primary" and "election"), users with a reputation of at least 150 can vote for who they want to be one of the new community moderators.


How to set custom DNS settings?

Question: I'm trying to set my Macbook Pro to use Google's public DNS, but when I go to the DNS settings (System Preferences > Network > DNS) it will enter the new IP address but then immediately reverts it to the original.
How can I fix this?
Comment: Need to ask you another thing, first: what kind of user do you use? Is it a superuser?
Answer: Did you follow this steps:
Mac OS X
DNS settings are specified in the Network window.
Example: Changing DNS server settings on Mac OS 10.5
From the Apple menu, click System Preferences, then click Network.
If the lock icon in the lower left-hand corner of the window is locked, click the icon to make changes, and when prompted to authenticate, enter your password.
Select the connection for which you want to configure Google Public DNS. For example:
    To change the settings for an Ethernet connection, select Built-In Ethernet, and click Advanced.
    To change the settings for a wireless connection, select WiFi, and click Advanced.
Select the DNS tab. (take note of the existing to be able to go back)
Click + to replace any listed addresses with, or add, the Google IP addresses at the top of the list:
    For IPv4: 188.8.131.52 and/or 184.108.40.206.
    For IPv6: 2001:4860:4860::8888 and/or 2001:4860:4860::8844
Click Apply and OK.
Test that your setup is working correctly; see Testing your new settings below.
Repeat the procedure for additional network connections you want to change.

To test that the Google DNS resolver is working:
From your browser, type in a hostname (such as http://www.google.com/). If it resolves correctly, bookmark the page, and try accessing the page from the bookmark. If both of these tests work, everything is working correctly. If not, go to step 2.
From your browser, type in a fixed IP address. You can use http://126.96.36.199/ (which points to the website http://www.eecs.mit.edu/) as the URL.* If this works correctly, bookmark the page, and try accessing the page from the bookmark. If these tests work (but step 1 fails), then there is a problem with your DNS configuration; check the steps above to make sure you have configured everything correctly. If these tests do not work, go to step 3.
Roll back the DNS changes you made and run the tests again. If the tests still do not work, then there is a problem with your network settings; contact your ISP or network administrator for assistance.

Possible limitations:
Routers
Every router uses a different user interface for configuring DNS server settings; we provide only a generic procedure below. For more information, please consult your router documentation.
Note: Some ISPs hard-code their DNS servers into the equipment they provide; if you are using such a device, you will not be able to configure it to use Google Public DNS. Instead, you can configure each of the computers connected to the router, as described above.
Comment: Yes, except for the part where it says to go to Airport since my Macbook doesn't have that option. I assume it meant WiFi.
Comment: You are correct :) and that set up is not working, gets reseated to the original DNS ?
Comment: Yes, resets as soon as I stop typing.
Comment: Try adding DNS when airport is off if you are changing for airport.

How to set custom DNS settings?


Root spread for Lime and Sweet Chestnut trees

Question: At the end of my garden I have some Lime and Sweet Chestnut trees.
I am wondering what the root spread can be. These trees are very mature, about 80 ft high.
Answer: Current thinking is that the significant roots of the tree will extend to at least the end of the branches that are farthest from the main trunk  (the drip line). Finer roots will extend out even farther depending on soil type and species of tree.
See here for details


Identification of TLS POODLE Vulnerability

Question: How can I identify whether the remote server is vulnerable to TLS POODLE vulnerability? Although, there are online scanners such as Qualys SSL Labs. As per my understanding, these online scanners do not work on custom ports such as 8086, 8909 etc. Also, these scanners cannot be used when we are performing the security assessment on internal network devices.
Answer: Poodle attack works on SSLv3 although there is a variant of poodle attack on TLS that appeared in recent years by accepting incorrect padding after decryption.
nmap is checking the TLS/SSL version. You can find the script of poodle identification rules online.
It is recommended to completely disable SSLv3 on server side.  On the client side, you should always upgrade to the latest version. Also, most of the browsers/servers use "TLS Fallback Signaling Cipher Suite Value (SCSV) for Preventing Protocol Downgrade Attacks" to prevent any intentional downgrade of version and drop the connection.
Answer: I personally like https://testssl.sh/, will check a lot of things and is just one script that manages all issues. If you have a look to the documentation (https://github.com/drwetter/testssl.sh/blob/3.1dev/doc/testssl.1.md) on the section "Basic parameters" you can find a full description of how to manage the ports.
Comment: While I personally use this script as well, please expand your answer a little. For example, how to scan custom ports (which is what OP asked for), or how the output looks like for poodle. For example, the `-O` option only scans for POODLE.
Answer: You can use nmap:
<code>nmap -sV --version-light --script ssl-poodle -p 8086 example.org
</code>
Comment: Rather than posting a one-liner, please explain what it does. It's not very useful to people who have not used nmap before, and blindly copying commands off the internet without understanding them is a bad idea.
Comment: @ShivSahni why do you think that?
Comment: My understanding says that this script will not identify TLS POODLE.
Comment: Checking whether it is vulnerable on port 8086(-p 8086).


Logitech Touchpad T650 does not click

Question: I have just received this Logitech Touchpad T650. The problem is that on my Ubuntu 12.10 desktop, the left or right tap clicks don't work while I can navigate and scroll with the touchpad. Any ideas to fix this?
Thanks
Comment: Related question: http://askubuntu.com/q/229883/6969
Answer: As far as I've read/found, it behaves like a basic laptop touchpad on Ubuntu with the exception of two-finger scrolling (old school, not natural like touch screens). Tap clicks don't work and there aren't any pointer tools for it like those available for Windows...
For those wondering, it sort of gets the job done, but it's not really fully working yet. Unless some update has escaped me, the T650 is definitely NOT worth buying for Ubuntu machines right now.
Answer: You need to update the touchpad T650 firmware. In order to do that, you will need a Windows box.
Go to the link below and follow instructions.
http://www.logitech.com/en-us/support/touchpad-t650?section=downloads&crid=398&bit=32&osid=14&softwareid=11370
After firmware upgrade, it's working as expected on Ubuntu.
Answer: I am adding this to expand on the firmware upgrade, which helps to enable all functionality under linux.
I have spent some time figuring out how the update works, so I want to leave it for you to pick up when needed.
You will NOT do this with the USB cable connected, this update happens via BT:

You need to download the 'Logitech Unifying Software' (LUS) from the same page above and install it on a windows box (There is no firmware update you can download for XP, I did this on W7 via VirtualBox VM)
You need to download the update file that is called something like: RQM_041_001_00038.exe, and RUN it, seemingly nothing happens, but the file copies itself from to the LUS install location so it can be picked up
Restart
Start LUS and click 'Advanced' to see the paired devices
Add the touchpad by switching it ON with the receiver in USB

I use the same brand keyboard, so it is useful to look at something like Solaar package to enable use of just one receiver for both devices.
sudo add-apt-repository ppa:daniel.pavel/solaar
sudo apt-get update
sudo apt-get install solaar

Answer: On most Ubuntu distros 18.04 and beyond, at least, the Logitech T650 works fine; I use it everyday. There is one caveat with Lubuntu/Kubuntu, i.e., the KDE desktop; tapping-as-click and "natural scrolling" are not enabled by default. To enable them, you must run xinput and the appropriate commands. An example sequence is below. It's possible that installing synclient might fix these issues more permanently, but I found the default config with synclient even worse, so I abandoned it.
Here's an example sequence:
xinput
Check your devices; look for the Logitech touchpad's device number. Let's pretend it's number 12.
xinput list-props 12
Look for the libinput tapping enabled and libinput natural scrolling enabled to find their numbers. Let's pretend tapping is 290. 0 is off, 1 is on.
xinput set-prop 12 290 1
Unfortunately, this resets every time the computer restarts; I've yet to figure out how to make the changes permanent, though it may just be that I need to sign in as root or something. You can write a bash script to speed it up, but the number assigned to the device will sometimes change, meaning you may need to include a variety of numbers to ensure you'll get the slot it's using at the moment.

Logitech Touchpad T650 does not click


Integrating EMF and view in plugin project

Question: I created an EMF project and tested using <>.editor project generated by .genmodel file by creating a new project and a file through "Example EMF Model Creation Wizards". Is there any way that a view (in plugin project) can be created directly (probably project & file are automatically created when user runs the application)? I dont want the user to create these things. It should be automated and presented in a view.
Answer: In the .genmodel file, set .genmodel --> All ---> Runtime Platform to RCP.  This creates an RCP app that does not use all the plugins of the IDE.  If you want, you can generate your app to run in the IDE... However, for this answer I will simplify and assume you generated an RCP app.  Go into the XXX.editor generated plugin, and into the .plugin file --> extensions.  Add a new (org.eclipse.ui.views) View by declaring a new View extension -- see the Sample View for a template.  Make sure to keep track of the ID you give this new View extension.  Similarly add a new PerspectiveExtension extension.  Add a reference to this new PerspectiveExtension with your unique View ID.  In the View extension, click on the class link, this will create a skeleton ViewPart class. It is a good idea to put a public static final String YOUR_VIEW_ID = "com.yourplugin.ViewID" in that class.
This will get you started and if you added your new view to your perspective, it should be visible when running your EMF based RCP app.


"Instagram could not be downloaded at this time. No matter how I try I am not able to download the app. Pls Help

Question: So I currently have an iPad 3 and I download Instagram regularly using the iPhone only option option in the AppStore. I've downloaded it many times before but this time I keep getting the same message over and over
(Other apps I have been able to install as usual it's just this one)
I've tried a VPN,I've tried a reboot, I've tried changing the date/time
If there are any solutions to this please do help.
Comment: Do you get a message or any indication of whats going on?  And why have you downloaded it so many times?  Once should be enough.
Comment: Any luck getting Instagram to load?  If so, what was the issue?  If you solved the problem you should enter what you did as the answer and get the points.
Answer: That particular site could be temporarily out of service. I'd wait about 15 or 20 minutes and try again.  If that doesn't work I'd check using your iPhone if you have one. If you've downloaded Instagram once it should remember you and if you try a 2nd time the Get button on the link will become an Open button. See the image below from my iPad.


How can I remove soap and toothbrush holders?

Question: What is the safest and least damaging way to remove existing soap and toothbrush holders from drywall? We would like to remove these holders because we do not use them. It seems the previous owner must have glued them to the wall and perhaps this is the proper convention. Is there a way to remove them without damaging the drywall terribly?
Comment: The usual convention with wall-mounted bathroom accessories is usually that an anchor is installed in the drywall and the accessory is mounted over that and secured with a small screw on the bottom. It is tough to say whether that could be the case on yours without seeing photos.
Comment: they might be screwed in can we see some pics?
Comment: How old is the place? What material are they made of? I am remodeling my bathroom and when I removed the soap and toothbrush holders, I found that there had been a hole cut in the drywall and they were plastered in place. They were surrounded with tile on the walls too, however.
Answer: If they really are glued to the wall, a heat gun on low might melt the glue enough to get them off. Then heat the remaining glue and scrape it off.


Simplest design approach for PWM control with power MOSFET

Question: I'm designing an application in which the current running into a load is controlled by PWM. A microcontroller generates a PWM cycle at 20kHz and this signal is used to control a MOSFET which is directly connected to the load. The load absorbs 10A at 100% duty cycle, at 12V DC.
The load is a thermoelectric module and the purpose of the circuit is to have a basic temperature control. No fancy features are required, just the easiest and wastless design approach.
Which is the easiest configuration in order to achieve this?
My basic understanding is that a pattern like MCU>mosfet driver>mosfet>load would be the best option. How could the "black box" mosfet driver + mosfet possibly be designed in order to minimize the number of components while keeping a low level of EMI and dissipated power?
Comment: Use a MOSFET driver IC that is specified for gate drive requirements of the power MOSFETs, ergo minimum part count: Decoupling capacitors, a couple of resistors, that is it. The power MOSFETs should have protection diodes attached in reverse polarity, even if they have internal body diodes, else they may die: A common cause of MOSFET failure. For reducing wasted energy, drive MOSFETs hard into on / off state while transitioning in the respective direction, and minimize transition time - the longer the FETs stay in the knee part of their graph, the more power is wasted as heat.
Answer: Here's a circuit I did a few years ago that demonstrates a driver chip local to the MOSFET and an over-current protection in case the load shorted out. The MOSFET used is not as suitable as the BUK954 you mentioned on another question. I'd use that type for your job.

The load is assumed to be purely resistive. In fact the original circuit had two MOSFETs driving a transformer with a centre-tap to the positive supply rail and it didn't need fly-back diodes (it used snubbers) but your's might need a protection diode across the load.
Circled in red is a local +5V power rail used for the over-current monitor - this can easily be derived locally with a small linear regulator such as 78L05.
Also note the big array of capacitors to the left of the circuit that absorbs most of the transient energy locally produced by switching the load. The original design was switching at 600kHz so if you wanted to run faster than 20kHz this shouldn't be a problem but i wouldn't go above 100kHz for the sake of efficiency.


Can I put different note lengths on guitar pro (in one bar )

Question: I want to put different note lengths in one bar above or below each other but when I change a note in guitar pro then other notes change too, so I have to use ties for other notes and that's very nerve-racking
Do you know any way to solve this problem ?
Comment: For starters, your bars don't add up to the time signature.
Comment: @user45266 Don't blame OP for not fillilng measure correctly if they struggle to set proper note lengths.
Answer: You should look into using multiple voices (find a similar article for your GP version) - but make sure it's still playable. If it isn't playable, you should look into using multiple instruments.
To summarise the article, here's a screenshot showing what I mean (complete with some handy freehand circles). My screenshot is of Guitar Pro 7 so the icons might be in a different place in your version's UI, but they should look the same (or similar enough):

To switch between voices, you click on one of the numbers circled in red. You can have up to four different voices.
To view all four voices at the same time, so all of the notes are a solid black and not greyed out like in my screenshot, toggle the button circled in yellow. I personally like to only work on one voice at a time when writing music so tend to leave it toggled off, but if I want to see how readable my music is as a whole (ie the bar lines don't cross, it doesn't look too cramped, etc) then I'll toggle this.


Are there situations that greatly enhance the other elements in Avatar The Last Airbender?

Question: In Avatar The Last Airbender a major point of the plot is Sozin's Comet, which every one hundred years passes close to the planet and greatly enhances the power of Firebending. While there are normal periodic situations when an element might be slightly enhanced (Fire is stronger when the sun is out, Water when the moon is out, etc), are there other rare situations similar to the comet during which the other three elements (Water, Air and Earth) are greatly enhanced?
Comment: There is no information about that. The comet seems to be the only one, enhancing firebinding.
Answer: Thus far, the only other situations shown to increase a bender's ability are:

The full moon strengthens waterbending.  This could arguably fall under the moon simply being out, but this is the pinnacle of that circumstance. (i.e. bloodbending can only be performed under a full moon)
Water from the Spirit Oasis has unique properties that make it a powerful waterbending tool.

The Avatar Wiki says:

Furthermore, a Waterbender's power is strongest when he or she is situated in colder climates, during the winter, or near their native polar homelands.

I do not recall anything that explicitly demonstrates this in-show.
Comment: As far as I can recall, the Spirit Oasis is "just" a place of high spiritual power, thus enabling the Avatar to contact the spirit world. But it is not enhancing Waterbending.
Comment: OrigamiRobot, you may wish to add the following from the [Avatar:TLA bible](http://racebending.livejournal.com/117598.html): `Fault line energies strengthen the Earthbenders.`
Comment: @Rainer - hrm, I remember the proximity to the Moon Spirit helping waterbending.  I will remove that for now.
Comment: @OrigamiRobot Proximity to the Moon Spirit may help in the same manner as the full moon itself - the Moon Spirit being an earthly embodiment of the moon.
Comment: god only knows what happens to waterbenders during lunar eclipses
Comment: There is also a tea which increases the Earthbender powers (strength and energy tenfold). When Aang drinks the brew, he becomes hyperactive. https://www.youtube.com/watch?v=A_0lfaJOMlw


Is the consumption of a DC motor linear?

Question: I mean, if we know that the motor consumes 100A to move a 10kg load, will it need 10A to move a 1kg load?
Comment: Only approximately. You may find it takes 5 or 10A to move itself (0 load) and then 10A per additional kg.
Comment: The  *torque* is a linear with the current (within the rated range of course).
Comment: It depends on tons of things. The only thing we can say for sure is that moving a 10 kg load will require less than or equal to the same current as the 100 kg load. If you are moving a weight up a hill on a cart that ways 1kg, then yes, it will probably take only 10 A to move it up the same hill. But if the cart weighs 1000 kg, then the load doesn't matter. And if you are moving at 100 kph, then the weight probably doesn't matter (it is all wind resistance).
Comment: You need to define what you mean by "move". Newton says an object in motion stays in motion. In the absence of things like friction or drag any tiny application of force will eventually accelerate an object of any mass to a given speed. The easiest example to think of spooling up a very, very heavy, but balanced wheel. The current of a DC motor is about proportional to the TORQUE, but the TORQUE applied is not the same thing as "moving".
Answer: The mass of the load doesn't matter, it's the energy expended.  If you're moving it downhill, it will take virtually no energy and, with some motors, might give some back.
Let's assume you mean "lift" as in moving it directly upward from the surface of the earth.  Assuming they're both lifted to the same height, the larger weight will have a proportionally larger energy requirement.  Assuming further that they're lifted at the same rate, the power used during that time will be proportional to the energy expended.
This is where it gets tricky.  Power is the product of voltage and current.  If you're feeding the motor a constant voltage, the current will increase with the square of the power.  However, if you're using voltage as a means of controlling the motor speed, the current will be affected by the voltage/torque curve.
Many DC motors are controlled with pulse width modulation (PWM) so the power is the product of the instantaneous power and the duty cycle.
This analysis assumes ideal power conversion and omits wasted energy in friction, deformation, heat, etc.
Answer: A DC motor has a commutator that will put the stator and rotor fields at the same angle, so the resulting force is sort of the product of the field strengths.  Now some DC motors use a permanent magnet for one of the two fields; in this case the resulting force (and summarily torque) will be in first approximation linear to the flowing current.  Other DC motors use a solenoid for both: in this case the resulting force (and summarily torque) will be quadratic to the flowing current, assuming the respective solenoids are in series.  At slow rotation speeds, the resistance of the coils is essentially ohmic in nature, so if they are wired in parallel, again the torque will be quadratic to the flowing currents which are both linear to the applied voltage.
The dynamic (speed-dependent) behavior will be more complex.


Power supply for micro-controller from 2 wire lamp switch

Question: I'm not a professional electronics person. For some time I'm playing with the thought of adding to the existing non-smart electrical infrastructure some kind of smart traits. All lamp switches get only phase (live) line 220VAC (or 110VAC). This poses a challenge to create a DC power source to power a micro-controller at the location of the switch. This power supply should provide very low power. Less than 0.5W. It should be small enough to fit into the switch box with a micro-controller and some not too much more electronics.
I wonder if there is already a solution for this? I thought perhaps the power supply could be connected in serial to the switch and perhaps will reduce the voltage going to the load by a few volts. When the switch is open, the power supply will get its source from the phase and will close loop through the load assuming that the load has low enough resistance characteristics. Something like what is shown in the following diagram:

The switch in the diagram will eventually be some semiconductor switching component controlled by the micro-controller. But for the matter of the discussion, it can be a regular mechanical switch. The load can consume up to 16 Amps (or twice in case of 110VAC).
Answer: This is often done by "2 wire" PIR or light controllers, but it has a two potentially significant issues.
Firstly the switched load has to let through the low current when "off" This works with tungsten bulbs, but causes issues with many Led or low energy bulbs.
Secondly you have the potential safety problems, when an "off" bulb holder still has the current going through you device. From personal experience I know this is enough to "sting"!
I would generally avoid this kind of circuit unless absolutely necessary.


Matlab strcat function troubles with spaces

Question: I'm trying to accomplish this:
strcat('red ', 'yellow ', 'white ')

I expected to see "red yellow white", however, I see "redyellowwhite" on the command output. What needs to be done to ensure the spaces are concatenated properly? Thanks in advance.
Comment: @#$@!#$@! another gotcha inconsistency between Matlab and C. >:(
Comment: Fast workaround: `cstrcat("he ", " l ", " lo")`, preserves the spaces.  Source: http://stackoverflow.com/a/14025999/445131
Comment: There are so many idiotic design decisions in Matlab, but I didn't expect something as simple as this to be a problem, too!
Answer: Although STRCAT ignores trailing white space, it still preserves leading white space. Try this:
strcat('red',' yellow',' white')

Alternatively, you can just use the concatenation syntax:
['red ' 'yellow ' 'white ']

Answer: From the matlab help page for strcat:
"strcat ignores trailing ASCII white space characters and omits all such characters from the output. White space characters in ASCII are space, newline, carriage return, tab, vertical tab, or form-feed characters, all of which return a true response from the MATLAB isspace function. Use the concatenation syntax [s1 s2 s3 ...] to preserve trailing spaces. strcat does not ignore inputs that are cell arrays of strings. "
Answer: In fact, you can simply use the ASCII code of space: 32. So, you can solve the problem like this:
str = strcat('red', 32, 'yellow', 32, 'white');

Then you will get str = 'red yellow white'.
Comment: Wow, funny that this works, even though `strcat('red', ' ', 'yellow', ' ', 'white')` removes the spaces...
Answer: You can protect trailing whitespace in strcat() or similar functions by putting it in a cell.
str = strcat({'red '}, {'yellow '}, {'white '})
str = str{1}

Not very useful in this basic example. But if you end up doing "vectorized" operations on the strings, it's handy. Regular array concatenation doesn't do the 1-to-many concatenation that strcat does.
strs = strcat( {'my '}, {'red ','yellow ','white '}, 'shirt' )

Sticking 'my ' in a cell even though it's a single string will preserve the whitespace. Note you have to use the {} form instead of calling cellstr(), which will itself strip trailing whitespace.
This is all probably because Matlab has two forms of representing lists of strings: as a cellstr array, where all whitespace is significant, and as a blank-padded 2-dimensional char array, with each row treated as a string, and trailing whitespace ignored. The cellstr form most resembles strings in Java and C; the 2-D char form can be more memory efficient if you have many strings of similar length. Matlab's string manipulation functions are polymorphic on the two representations, and sometimes exhibit differences like this. A char literal like 'foo' is a degenerate one-string case of the 2-D char form, and Matlab's functions treat it as such.
UPDATE: As of Matlab R2019b or so, Matlab also has a new string array type. Double-quoted string literals make string arrays instead of char arrays. If you switch to using string arrays, it will solve all your problems here.
Comment: Great, that helped me when I wanted to concatenate several string cell arrays with a `' '` character: `dateTime{:} = strcat(date, {' '}, time)`
Comment: This has helped me too to preserve whitespace.  Good trick to know.  BTW, you're very close (if not already) to 1k for the MATLAB tag.  Early congratulations on getting the gold :)
Comment: Great tip. I was just looking for this.
Comment: Shameless plug: I go in to all this in more detail in this blog post: http://blog.apjanke.net/2019/04/20/matlab-string-representation-is-a-mess.html
Answer: or you can say:
str = sprintf('%s%s%s', 'red ', 'yellow ', 'white ')


Switching from Panopoly

Question: I'm wondering if anyone has experience switching a Drupal installation away from Panopoly. I have a site built on Panopoly, but I'm finding the upgrade situation stifling. I'd rather have independent control of which modules are installed. So I'm looking to move to a vanilla core installation and do all the modules by hand. Anyone with firsthand experience doing this? I'm just going to give it a whirl and see how it goes, but any tips would be appreciated. Thanks!
Answer: You can use Profile Switcher

Used to switch between install profiles found in /profile directory.
  This module is useful for moving an existing site to distribution.

I had the same problem last year you can check it out at - Changing from a Profile to Standard profile after the installation
Comment: Looks great! Definitely seems like the way to go. I'll give it a try this week.
Comment: A note for anyone looking to switch from Panopoly specifically: Profile Switcher didn't seem to do anything at all. I did some manual moving around of modules, and updating the registry and registry_file tables and truncating the cache tables in the database. The next step was figuring out how to extricate the site from Panopoly-specific versions of modules and content types, which is where I left off. I'm sharing this to indicate that profile-switcher might not be helpful, to share some of the steps I took, and to maybe give a sense of the magnitude of the project.

Switching from Panopoly


Geoprocessing breaks my data links after upgrade?

Question: I've had this problem all day, and it's happened before, too. I am running desktop 10.3.1 and want to produce a very simple buffer from a single parcel. The output is assigned to the same .gdb that the buffer output is assigned to. When I run the buffer, every other feature class in the map from that .gdb breaks the data link and I end up with a map full of red exclamation points, except for the most recent layer.
Occasionally this happens even when all I am doing is exported selected features into their own layer. Has anybody else experienced this?
Comment: No, that's weird. I think you'll have to lodge that with Esri support. Is your GDB and map version 10.3.1? Were they created before? Perhaps upgrading the database to the current version and saving the MXD might help but it sounds more fundamental than that... time to use Esri support.
Answer: I suspect that the default location into which outputs of your geoprocessing tools are written, has been reset by the upgrade.
Next time you run a tool pay careful attention to the workspace into which the output is being written, and check that against the source of any layer that you are expecting it to overwrite.