system() vs execve()

Question: Both system() and execve() can be used to execute another command inside a program. Why in set-UID programs, system() is dangerous, while execve() is safe ?
Answer: system will call the shell (sh) to execute the command sent as an argument. The problem with system because the shell behavior depends on the user who run the command. A small example:
Creating a file test.c:
#include <stdio.h>

int main(void) {
    if (system ("ls") != 0)
        printf("Error!");
    return 0;
}

Then:
$ gcc test.c -o test

$ sudo chown root:root test

$ sudo chmod +s test

$ ls -l test
-rwsr-sr-x 1 root root 6900 Dec 12 17:53 test

Creating a script called ls in your current directory:
$ cat > ls
#!/bin/sh

/bin/sh

$ chmod +x ls

Now:
$ PATH=. ./test
# /usr/bin/id
uid=1000(cuonglm) gid=1000(cuonglm) euid=0(root) egid=0(root) groups=0(root),
24(cdrom),25(floppy),29(audio),30(dip),44(video),46(plugdev),105(scanner),
110(bluetooth),111(netdev),999(docker),1000(cuonglm)
# /usr/bin/whoami
root

Oops, you got a shell with root privileges.
execve does not call a shell. It executes the program that passed to it as first argument. The program must be a binary executable or a script start with shebang line.
Comment: @JoelDavis: No, you still have problem, even if you use full path. If you use `/bin/ls`, the user can add `/` to `$IFS`, causing the shell split `/bin/ls` to `bin` and `ls`. Now, an executable called `bin` in current directory can do the same thing as `ls` in my answer.
Comment: @JoelDavis, no, you'd need at least to clear the whole environment, give sane default values to a few envvars (PATH, HOME...), if needed preserve some env vars after sanitising (TERM, DISPLAY, LANG...) make sure fds 0, 1, 2 are open... Basically do what sudo does. Even then, I wouldn't go there. Don't invoke a shell in privilege escalation context if that can be avoided. Note that `ls` can do fancy things with its environment, so even without `system()`, you should probably sanitise the environment. When using setuids you want to minimise what is done as root (typically not execute commands).
Comment: Thank you both. This was actually a pretty interesting answer.
Comment: Not saying `system()` is without problems but wouldn't the above be resolved by using absolute paths in the binary executable?
Comment: If execve will run a shebang, I don't see where it matters.
Answer: system() and execve() work in different ways.  system() will always invoke the shell and this shell will execute the command as a separate process (this is why you can use wildcards and other shell facilities in the command line when using system()).
execve() (and the other functions in the exec() family) replaces the current process with the one being spawned directly (the execve() function doesn't return, except in case of failure).  In fact system() implementation is supposed to use a sequence of fork(), execve() and wait() calls to perform its function.
Of course both are dangerous depending on what is being executed when the process has root privileges.  system(), though, brings some extra dangers due to the additional shell "layer" it uses that opens room security breaches as it invokes a root shell as in the case of your question (i.e., the process has the suid bit).
Comment: So when using execve() .. you mention it replaces current process .. would the process remain setuid ?
Comment: Yes.  The "new" process initiated by execve inherits a number of properties of the one being replaced, like filedescriptors, sockets, etc. and the effective uid is one of them, but there are situations where the uid changes during the execution of execve, like if the executable pointed by the execve parameter has the suid bit set.  In this case, the uid is changed to the file owner as it is defined in the filesystem.
Answer: Apart from the metioned security issues with system(), the spawned process inherits the main program's environment. This can be very problematic when using suid, for example when the calling process sets LD_LIBRARY_PATH-environment variable.
With the exec()-family the calling program can set the environment to exactly what's needed (and safe) for the called program before calling exec().
And of course the shell called by system() can have security issues itself.
Comment: Environment variable LD_LIBRARY_PATH will be ignored when setuid program is run by non-root user except when the real uid is also 0.

system() vs execve()


Symfony 2 - Working with assets

Question: I need some tips on how to work with assets in Symfony 2. For example, do we have to always perform the assets:update every time an image is added ? I know Assetic take care of the management on css and javascript files but what about images? What would be the best practice for the front-end development with Symfony 2 ? How do you guys setup your css, images and js files in your app to make it easy to develop, deploy and change ?
Comment: Is `assets:update` a real command?  I've not found it mentioned anywhere else, and can't find it in the Symfony/Assetic codebase.  If it does exist, I'd be interested to know more about it.
Comment: Related: http://stackoverflow.com/questions/12123069/how-to-properly-change-what-composer-or-symfony2-does-after-running-composer-up
Answer: Regarding images, if you added it into your public folder, I think there's no need to perform assets:update
However, if you add the image within the resources folders of a bundle, you might have to, depending on your OS and which options you used when called assets:install
If you're using an OS which supports symlinks (linux, OS X, and I guess all OS but Windows), you can install the assets calling (I don't exactly remember the call, the important thing here is the symlink option):
php app/console assets:install web --symlink

This way, instead of having a copy of each bundle's resources, you'll have a symlink, so there should be no need to update. If you have an OS which doesn't support symlinks, I think you'll have to keep updating or reinstalling assets (in fact, I always used assets:install, I didn't knew there was an update option :P).
Regarding the set up, I usually put all css, js, images and any public resources inside a bundle if it is used only within the bundle, and place it onto the public folder if it's used by many bundles, or I plan to use it in other bundles.
Comment: Also, if you're using Composer to update your vendor packages, don't forget to set the `"extra": { "symfony-assets-install": "symlink" }` in your composer.json file ([see docs](http://symfony.com/doc/current/book/installation.html#updating-vendors)).
Comment: The `symlink` also work on Windows when you are running cmd (or git bash) under Administrator mode. :) because Assetic works with http://php.net/manual/en/function.symlink.php which is supported on Windows.
Answer: As of Symfony 2.7 this will generate relative symlinks in web directory:
php app/console assets:install web --symlink --relative

In composer.json add:
"extra": {
    "symfony-assets-install": "relative"
}

This will also generate relative symlinks on composer update.
Comment: Since composer.json is committed, and thus used during the install on a production environment, I'm not sure you want this in your composer.json directly.
Answer: Here is cool think about --symlink.You can configure(config) one time and use forever.If you want more http://www.w3docs.com/snippets/symfony/how-to-keep-symlinks-in-web-bundles-after-composer-update.html

Symfony 2 - Working with assets


Difference between button and which in mouse events

Question: What is the difference between event.button and event.which in Javascript mouse events?
Comment: `button` for `mouseDown` and `mouseUp`, `buttons` for `mouseMove`, and don't use [which](https://developer.mozilla.org/en-US/docs/Web/API/MouseEvent/which)
Answer: event.button
Indicates which mouse button caused the event.
event.which
According to jQuery's documentation:

...event.which also normalizes button presses (mousedown and mouseupevents), reporting 1 for left button, 2 for middle, and 3 for right. Use event.which instead of event.button.

Difference
In all modern browsers (IE8+) event.button will give you the following values:
0   Specifies the left mouse-button
1   Specifies the middle mouse-button
2   Specifies the right mouse-button

While in IE8 and earlier:
1   Specifies the left mouse-button
4   Specifies the middle mouse-button
2   Specifies the right mouse-button

event.which standardize these results by providing you the following values:
1   Specifies the left mouse-button
2   Specifies the middle mouse-button
3   Specifies the right mouse-button

Comment: Hm yes, but both seem to indicate the mouse button - what exactly is the difference?
Comment: Let me give you a further example.
Comment: @chopper, I believe my last edit answers your question.
Comment: Yes, specifically for the mouse events. For the keyboard events it normalizes `event.keyCode` and `event.charCode`.
Answer: I'm relatively shy to the last solution despite my upvote. According to the MDN documentation :
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future
So, MouseEvent.button is still prefered.
An interesting (case) alternative could be MouseEvent.buttons which permits you to determine all buttons pressed when the event is triggered.


Exercise in testing a difference of means

Question: A random sample of 49 Kwakiutl native Americans reported that they went fishing an average of 68 days each year. Information from a non-native local population showed that they fished an average of 66 days per year (sd = 14). Do the Kwakiutls fish more than the non-Kwakiutls and if so is it a big difference?
Comment: Welcome to the site, @Diane. Please don't write in all caps, this bothers many people, & it is harder to read. Is this homework? What is *your* question here? Please read our [FAQ](http://stats.stackexchange.com/faq), which explains site policies regarding questions, homework, etc.
Comment: In addition to @gung's comments, why is this titled "sample vs. population"?
Answer: Concerning the question "is it a big difference" probably your teacher wants you to wrestle with the concept of "effect size", perhaps after testing to see if the difference of 2 days is statistically significant.  You can also approach the question of the size of this 2 day (3%) difference by asking questions such as:  If the average non-Kwakiutl can feed his/her family by fishing on 66 days, why does it take 68 days for the average Kwakiutl? Are their families larger? Bigger eaters?  Do they fish less efficiently? Also, does fish keep for 5 days (365/68 is about 5)? What do the people eat on the days they are not fishing?  But if you ask these questions you might find out that the data are hypothetical and there are no answers to these questions.  You may just have a hypothetical data set to provide a statistical exercise to help you learn about effect size and/or statistical significance.  Look up "effect size" and "statistical significance" in your textbook (if it is not clear, try another textbook).  To measure effect size you might use a difference statistic usually denoted by the letter "d".  To test for statistical significance you might use a t-test or a z-test.  Good luck.


What chess software allows to search for sacrifices and combinations?

Question: I want to search a database of games for generic interesting tactics combinations. What are my software options for this (SCID/CB/CA)? Is there a published algorithm/script that determines that a move is a sacrifice/combination? I see that Chessbase allows this: as per http://help.chessbase.com/Reader/12/Eng/index.html?search_sacrifices.htm, but I would be curious to see if other software does something similar, and also want to know more details behind these algorithms: "The ChessBase sacrifice search does a look-ahead in all tactical situations and for this reason takes somewhat longer than the other searches. The algorithms were written by Dr. Christian Donninger, the author of Nimzo."
Answer: The http://ChessTempo.com tactis trainer is based on tactical problems extracted from a large database scanned with an engine and the problems have been tagged with tactical motifs by users. Perhaps it is sufficient for your purpose if you learn to create custom problem sets based on these tags. There is a discussion forum there where you can ask your question in detail.
Answer: Chessbase 17 exactly does what you want. I love this feature. I just added a recent search for sacrifice and this is the result, off course one from many. I have attached the screenshot for you to understand quickly. This sacrifice of bishop crashed the entire game of the black and in next move, he resigned. He placed his king on d-8.
http://help.chessbase.com/Reader/12/Eng/index.html?search_sacrifices.htm


Can I see the specs of the memory card used within the metadata of an image?

Question: I want to see the specs of the particular memory card (or serial number) I used on a particular image. Is this possible?
Comment: What problem are you trying to solve? What is do you want this information for?
Answer: No, this is not part of the standard for EXIF, which means there's no standard way to store it in image files.
Comment: @PhilipKendall Is it possible that cheap knock-offs of brand name flash memory cards would all have the same serial number? Many reverse engineered third party lenses use this strategy to get cameras to recognize/work with them.
Comment: "Second, there's no standard for communicating this from the card to the camera." I think there is - [the CID register contains the serial number](https://www.cameramemoryspeed.com/sd-memory-card-faq/reading-sd-card-cid-serial-psn-internal-numbers/) so there's no reason the camera couldn't read that.
Comment: @MichaelClark Anything is possible - but my impression is that the knock-off merchants are wise to this specific trick. No proof though and getting off topic for photo SE.
Answer: No, It's not possible. Because in the current design image doesn't includes the memory card information like seriel numbers. Because it'll not effect to image quality.
For more details about EXIF, please refer below link:-
https://www.makeuseof.com/tag/exif-photo-data-find-understand/


How can I press "Insert" on a keyboard without that key?

Question: I have lenovo flex. It does not have numpad. I am using ubuntu OS.
Answer: If you look closely at your keyboard, you can see that there is a button dedicated to Insert.

Image by PC Perspective
As you can see from the picture in the bottom right, the PgDn key has Insert as secondard function, accessed by the Fn key.
In order to use it, press the combination Fn + PgDn.
Answer: There is an Insert key on all the pictures of the Lenovo Flex I could find (top row of keys, to the right, actual position depending a bit on the Flex model).
Comment: You can use the ``-tag for keyboard keys.
Answer: If you have an PRT SC (print screen) key and a FN (function) key, press and hold the 'fn' key and then press the 'prt sc' key, and then release both at the same time. This should toggle the insert on or off. Sometimes the 'prt sc' key has the letters 'ins' on it as well.
Comment: https://c1.neweggimages.com/productimage/AAD0_1_20160708522617326.jpg
Print screen button does not have secondary function on function key. What I really need is to switch functionality of a key may be right ctrl button to insert key.

How can I press “Insert” on a keyboard without that key?


Are Catholic children given Saints' names on Confirmation?

Question: In a paragraph of the write-up on Roman Catholic Saints at britannica.com , it is written that many Catholics take or are given a saint's name for their Confirmation. Normally, a Catholic child on its Baptism is given a saint's name which may be different from the child' s  name as entered in civil records. But are there places where children are given saint's names on their Confirmation ?
Comment: I dont think its universal, I'm from Mumbai and we dont do that here.
Answer: Yes. Catholic.com has a Q&A (What happened to confirmation names?) which addresses your question very nicely (including your question about the name given at Baptism):
Answer:
The custom of adopting a saint's name at confirmation was done in order to adopt the saint as a special heavenly patron or to honor a saint to whom one had a special devotion. In short, the purpose was to give the confirmand the opportunity to develop his understanding of and reliance on the communion of saints.
While the practice is still in use today, some dioceses have encouraged returning to the older tradition of not picking a new name at confirmation. The idea is that the person is already supposed to have a Christian name, given to him in baptism, and that continuing to use that name at confirmation will serve as a link between these two sacraments of Christian initiation.

My diocese in the United States asks children preparing for Confirmation to choose a saint's name to be used at their Confirmation.
Confirmation names are also referenced in many other places on the Internet, such as on Loyola Press' website.
Comment: "...some dioceses have encouraged returning to the older tradition of not picking a new name at confirmation..." That is a pity. The name that is assigned at birth encodes the expectations of the parents, regardless of whether or not the parents are Christians. By the time the child is old enough to be confirmed, they have started to form their own expectations. Maybe she could pick the patron saint of astronauts, or brain surgeons, or corporate lawyers...
Answer: Are Catholic children given Saints' names on Confirmation?
The short answer is yes, but this tradition is not completely universal. We should also keep in mind that Eastern Rite Catholics baptize and confirm their children as infants, whereas in the Roman Rite Confirmation is done around the "age of reason" or even later.

Practice regarding names
But while various Fathers and spiritual writers, and here and there a synodal decree, have exhorted the faithful to give no names to their children in baptism but those of canonized saints or of the angels of God, it must be confessed that there has never been a time in the history of the Church when these injunctions have been at all strictly attended to.
The point however cannot be dwelt on here. We may note on the other hand that a rubric in the official "Rituale Romanum" enjoins that the priest ought to see that unbecoming or ridiculous names of deities or of godless pagans are not given in baptism (curet ne obscoena, fabulosa aut ridicula vel inanium deorum vel impiorum ethnicorum hominum nomina imponantur). Some of the seventeeth century French rituals have gone further than this. For example that of Bourges (1666) addressing parents and godparents urges: "Let them give to boys the names of male saints and to girls those of women saints as right order requires, and let them avoid the names of festivals like Easter (Pâques), Christmas (Noël), All Saints (Toussaint) and others that are sometimes chosen." Despite such injunctions "Toussaint" has become a not uncommon French Christian name and "Noël" has spread even to England.
In Spain and Italy again, ardent devotion to our Blessed Lady has not remained content with the simple name Maria, but many of her festivals etc. have also created names for girls: Conceptión, of which the diminutive is Concha, is one of the best known, but we have also Asunción, Encarnación, Mercedes, Dolores etc. in Spanish, and in Italian Assunta, Annunziata, Concetta, etc. It is strange on the other hand that the name Mary has by no means always been a favourite for girls, possibly from a feeling that it was too august to be so familiarly employed. In England in the twelfth century Mary as a Christian name is of very rare occurrence. George again is a name which despite the recognition of the warrior saint as patron of England, was by no means common in the thirteenth and fourteenth centuries, though strangely enough it grew in popularity after the Reformation. A writer who has made a minute examination of the registers of Oxford University from 1560 to 1621, has made out the following list of the more common names borne by the students in order of popularity: John, 3826; Thomas 2777; William, 2546; Richard, 1691; Robert, 1222; Edward, 957; Henry, 908; George, 647; Francis, 447; James, 424; Nicholas, 326; Edmund, 298 (see Oxford Hist. Soc. Transactions, XIV). In Italy and Spain it has always been a tolerably common practice to call a child after the saint upon whose feast he is born.
Confirmation names
The practice of adopting a new name was not limited to baptism. Many medieval examples show that any notable change of condition, especially in the spiritual order, was often accompanied by the reception of a new name. In the eighth century the two Englishmen, Winfrith and Willibald, going on different occasions to Rome received from the reigning pontiff, along with a new commission to preach, the names respectively of Boniface and Clement. So again Emma of Normandy, when she married King Ethelred in 1002, took the name Ælfgifu; while, of course, the reception of a new name upon entering a religious order is almost universal even in our day. It is not strange, then, that at confirmation, in which the interposition of a godfather emphasizes the resemblance with baptism, it should have become customary to take a new name, though usually no great use is made of it. In one case, however, that of Henry III, King of France — who being the godson of our English Edward VI had been christened Edouard Alexandre in 1551 — the same French prince at confirmation received the name of Henri, and by this he afterwards reigned. Even in England the practice of adopting a new name at confirmation was remembered after the Reformation, for Sir Edward Coke declares that a man might validly buy land by his confirmation name, and he recalls the case of a Sir Francis Gawdye, late Chief Justice of the Common Pleas, whose name of baptism was Thomas and his name of confirmation Francis (Co. Litt. 3a). - Christian Names

Ideally, a confirmation name should be the name of a saint whom you know something about, or who inspires you, or whose virtues you want to imitate. It is the name of a saint or holy angel who will accompany you through life. In some countries, names like Assunta after the Assumption of Mary are taken, thus their patron would be the Virgin Mary.
If your given name at birth is also a Christian Name one could freely use their given name when confirmed by one's bishop!
Again the custom of receiving another Christian Name at Confirmation is very commonplace within the Church, yet a few dioceses around the world do not insist or require it at all.


Can't use Ubuntu after opening laptop lid

Question: I am running Xubuntu 17.10, I upgraded from 17.04. When I open laptop lid, it stays in blank screen. Power is on, wired mouse doesn't get power, it doesn't respond to anything. I tried pressing keys and pressing power button. I always have to restart my laptop to use it. Xfce Power Manager says that it locks screen when lid is closed.
Answer: The laptop lid is one of the lingering issues with Linux on laptops, at least with Ubuntu. I usually have to go into the settings you are describing and fiddle with them until I find a configuration that I'm satisfied with.
For the purposes of troubleshooting, I would recommend asking XFCE to "Do Nothing" when the laptop lid is closed - don't suspend, don't turn off the screen, nothing. If it works, it will be a little weird, because the lid will be closed by the screen will be on.
After that, if you are able to open the lid and everything is working, I would recommend trying the "Blank screen" option. It's like pressing the power button on an external desktop monitor - shouldn't change anything about how the OS is running - browser should stay open, downloads should continue, etc. Perhaps "blank screen" is sufficient for your needs, in which case, you're good to go.
Otherwise, you will want to experiment with the "Suspend," "Sleep," or "Hibernate" options. Honestly, even with Windows, I find these to be more trouble than they're worth. The terms are used interchangeably, even though to the OS and to the BIOS the terms have very specific meanings. For instance, see "S1" and "S3" modes. This is a bit more involved to figure out which power state you want, exactly. If you really need this feature, I would read and become more familiar with the definitions of the different power states and how your OS deals with them.
Good luck, enjoy Xubuntu. I enjoy it quite a bit for older laptops.
Answer: I had the same issue.
what solved it for me was choosing a different option when the lid is closed in [Power Manager -> General -> Laptop Lid].
"Suspend" seems to do what you'd expect (put laptop to sleep on lid close, and wake it without issues on screen open), whereas "Lock Screen" seems to have those issues you were describing.


Why would light take time to reach distance if space and time are relative?

Question: I've read that according to speacial theory of relativity, the time slows down for moving object. If we think light itself as moving object the time is zero for that. Also the theory says the space also shrinks as much as time shrinks...if we assume time shrinked to it's max which is 100 causing it to stall and don't increase any second... Does it imply that space also would shrink to 100? And if yes then does that mean I'm going to receive the singnal from the object 10 light years ahead just in a snap? As the distance shrinked to 100 percent so 0 and time too.
Answer: The distance (and time) shrink from the viewpoint of the fast-moving object, but not from the viewpoint of a stationary observer.


sharepoint online backup site

Question: I got new issue from my client. He want to back up sharepoint site for restore, if something is going wrong. And the challenge is not to use 3rd party solution(MetaVis, AveDoc). Is there any other way to get back up? I think about to write my own application for backing up,maybe using CSOM, but i don't find a way to connect SharePoint storage(site description schema), where could I start? Please, share your experience if you had challenges like that.I want to find programmatic solution for this challenge.
Answer: From this link, we can see there are only 4 ways to restore data in SharePoint Online:

Site Collection Restore

Backups are taken every 12 hours, and are kept for 14 days.
You must contact technical support to perform a site collection restore.
The data will be restored to the same url that it was taken from.  You cannot restore to a different url, and you will lose any current data.

Recycle Bin

This is pretty self-explanatory.  Details can be found here and here.

Versioning

Again, this one is also pretty self-explanatory.  Details can be found here and here.

3rd Party Solutions

The more diverse and robust option of the four, the only downside is having to pay.
Usually allow you to backup/restore items at a more granular level.
Some options:

Avepoint
Quest
Metalogics
Metavis
Thinkscape
Comment: I know this four ways. But as I say I have no chance to use 3rd party solution like MetaVis and etc. So i think if this 3rd party solutions have some access to data, they maybe use the same csom. So there must be some way to access and backup data.

sharepoint online backup site


The speed of light is constant?

Question: In the proof that the speed of light is a constant we make the assumption that space at large scales is homogeneous, but there are patches of space where the density is higher and there are patches where it's lower. Does that mean that it is a little bit different in these patches? Maybe light could light travel faster or slower.
Comment: This seems like a perfectly good question to me. In fact a very similar question has been asked (and answered by me) in [Speed of light in a vacuum](https://physics.stackexchange.com/questions/44751/speed-of-light-in-a-vacuum) though this is not quite a duplicate. The downvotes seem completely unwarranted to me.
Comment: Related: https://en.wikipedia.org/wiki/Shapiro_time_delay https://physics.stackexchange.com/search?q=Shapiro+delay
Comment: see my answer here for "slow light" links. for faster than c it would not be possible IMO from Maxwell equations.
Answer: The proofs are experimental. See the Experimental Basis of Special Relativity for details. In particular, you will be interested in the observations from cosmological sources. Perhaps the most interesting will be Brecher's observations of binary pulsars as that particular paper used high energy observations which are not subject to criticism based on optical extinction.
Comment: How fast were the aircraft flying in the 1971 experiment?  Do you know?
Comment: I do not know. They were commercial flights, so it would have been less than Mach 1.
Comment: I did some digging.  When compared to some universal starting point - perhaps the sun, the clocks travelled at:   Westbound: 241 m/s   Earthbound: 463 m/s   Eastbound: 685 m/s   So compared to their starting airport, they were about 220 m/s or 792 k/h.    In reading the tests, it's funny that they say the westbound clock gained time, when this is only in comparison to the earthbound clocks.  It would have been much better for them to say the westbound clocks were (nearly) stable and the earthbound clock lost some time and the eastbound clock lost even more time.
Answer: You are correct that the speed of light "c" changes in different regions of space. This is because the speed of time changes in different regions.  You have heard of warped spacetime. I am just referring to the warped time part of that.
First, keep in mind that if you are inside that region of space, you will never see the change in c because you, and any clock you hold, will experience the exact same change in the speed of time.  But you can certainly notice it if you watch from a distant neutral point.
For example, imagine that there was a tunnel drilled right through Venus.  And someone standing on Mercury pointed a laser at Earth.  Before Venus crossed in between, the light would hit Earth in a certain time.  But when Venus passed in between Mercury and Earth, it would take longer for light to hit Earth because of the time dilation caused by Venus.  As you surmised, the density of mass in Venus caused a slowing of time and a slowing of the speed of light.
So in answer to your question, to a local observer the speed of light is constant. But to a distant observer, c can change because c simply reflects the speed of time itself.

The speed of light is constant?


Installing 30amp breaker

Question: So can I replace a 15single pole breaker with a 30amp single pole breaker with a 10gauge wire to an outlet even though im not going to use that much power? only for lighting building a grow room
Answer: Generally only 30A receptacles are allowed on 30A circuits, and 15 or 20A on 20A circuits, and 15A on 15A circuits.
210.23(B) Says a 30A branch circuit is permitted to supply fixed lighting units with heavy duty lamp holders in other than dwelling units...
So if the building occupancy in County records is residential you likely wouldn't be allowed to do that.
Alternately you install a $20 6 space electrical panel in the grow room and break your lighting circuits down to easier to handle 15A or 20A circuits and wire.
If in an allowed occupancy you are allowed to use cord and receptacle connections, but there are additional requirements in Article 422, including the receptacle is required to be directly above the light and stain relief issues.
Comment: Additionally standard 15A receptacles such as a Lev CR15-w aren't (UL) listed for #10 wire. The instructions are part of approved use.  https://www.leviton.com/en/docs/CR15_CR015.pdf
Comment: Excellent answer that covers the code requirements and nuances related to answer the question, as well as a good alternate option.
Answer: You could but you would not be able to have any standard 15/20 outlets on this circuit.  All outlets would have to be designed/rated for 30amp
If you did this and used 30 amp outlets, you would not have any overload protection at all for the lights, plugged or hare-wired.
Seems it would be better for you to run multiple circuits (15 or 20) to the grow room than to do all the work required to support the 30 amp circuit.
If your end goal is to install some device later that requires a 30amp circuit, then that a different issue.
Answer: If you already have the wire, yes, you can run it. You will still need a 20 amp breaker if installing the regular outlets. #10 AWG wire should fit in regular outlets but if you have difficulty doing it, you can pigtail it to some #12 AWG.
Answer: Yeah, you can't just use fatter wire and breaker if you want to power more stuff on a single circuit.
If the light had an internal problem, it would trip a 15A or 20A breaker, but not at 30A.  And you go "oh, that sounds super random" not at all, the light is engineered to fail that way. That's part of the UL listing (assuming it has one lol).
If you are dealing with modern lights, check if they are 120/240V multi-voltage.  If they are, then you can wire the circuit as 240V/20A using NEMA 6-15 receptacles.  That will give you 4800 watts instead of the 3600W you'll get with 120V/30A.
Answer: In one word: NO, outlets must be protected by AT MOST 20A so if the breaker is the only protection to that outlet, it must be 20A or less.
Assuming the outlet is a regular 15A or 20A
Answer:
So can I replace a 15single pole breaker with a 30amp single pole breaker with a 10gauge >wire to an outlet even though im not going to use that much power? only for lighting >building a grow room

The real question is Why do you need to upgrade to 30amps ? What are your plans ?
To me it sounds like you should be looking at a sub panel so you can divide up the circuits and if needed you can add more circuits at a later date.

Installing 30amp breaker


Can my ISP know my passwords

Question: If I am using some proxy service, proxy service provider can know my passwords to my online accounts. In which case my ISP can filter my requests and get my passwords to my online accounts? And how can I secure myself?
Comment: Even if you use a proxy service, that service would be unable to harvest your passwords, unless you were actually using them to make the secure connection.  If thats the case then nothing you do can protect your passwords considering the traffic at that point is basically not encrypted.
Answer: Your ISP can know your password any time it's sent unencrypted over your internet connection. If you don't want them to know your password, don't send it unencrypted over the internet:

Avoid login pages that use HTTP (always use HTTPS and don't visit sites with expired or invalid SSL certificates)
Don't use FTP or other services/protocols that don't encrypt your password in transit

Also follow general security guidelines for passwords, such as never reusing the same password.
Additionally, if you are worried that your ISP (or anybody else in between you and the remote server you're communicating with) is watching you, then you also need to take additional steps, such as:

Ensuring that all websites you are logged in to are using HTTPS, so that your cookies can't be snatched from the HTTP request (you're logged in to this site, where HTTPS isn't available, so your ISP can already log in as you here if they want to)
Verifying you are talking to the right server (for example, with SSH, ensure you use fingerprint verification and take notice if a server's fingerprint changes).

If you are only worried about your ISP (or your government), you can improve your position significantly by using an offshore VPN so that all of your traffic is routed through a server outside of their reach. Your data will still be sent unencrypted over the internet, but will be encrypted between the VPN and you, which is enough to prevent your ISP from reading it.
Comment: I should add that if you don't trust your government, you probably shouldn't trust the PKI (your government probably runs a root CA or can compel a root CA to sign a fake cert).
Answer: If you are not using HTTPS, then your passwords are at risk of interception. Using a VPN or an encrypted proxy means trusting the VPN and proxy provider. Only HTTPS can provide (as far as we know) reliable security without trusting anyone external. But attacks that weaken the SSL/TLS protocol exist, such as BEAST, CRIME and TIME.
You have to make sure your are using HTTPS on websites that have your sensitive data. Banks and Google will use HTTPS but for others, you have to configure them to use HTTPS. Facebook is a website that doesn't yet have HTTPS for everyone by default but you can turn it on using a few clicks.
HTTPS Everywhere is a Firefox and Chrome extension that encrypts your communications with many major websites, making your browsing more secure. "HTTPS Everywhere" makes sure you will not use the unsafe HTTP when HTTPS is available.
Comment: Even with HTTPS, you still need to trust the root certificate authority, and their key-signing process and security.
Comment: You're completely right, I failed to mention that, but it might be too in-depth for the scope of this explanation.
Comment: @CristianDobre - You really shouldn't have to explain that part of the equation, since in this context, your only telling readers that a secured connection should be used.

Can my ISP know my passwords


Can including continuous variable and its discretized form lead to problems in regression?

Question: This is a rather basic question regarding multicollinearity. Say that I want to use linear regression model to predict job happiness based on someones salary, since I assume that the relationship is not perfectly linear and the regression slope should differ in the low-paid and high-paid employees, I decide to use a model with interaction term for $\text{salary_group} \times \text{salary}$. On one hand, both variables are obviously correlated, on another, the model intuitively seems to make sense. Can this lead to any problems?
Comment: If nothing else it will lead to problems of interpretability. Unless you have a strong reason to look at income from both perspectives (categories and the actual number), don't do it. Such a reason could be tax brackets that constitute a finite set of containers that salary falls in and that are treated differently.
Comment: @David It might be complicated, but it can work.  One way to see this is to recognize that standard dummy-variable codings of the groups amount to an order-zero spline.  If instead we were a bit more sophisticated and used a higher-order spline, we would recognize this proposal as a perfectly standard procedure (and readily interpretable).  The interaction would look like an additional spline-like term contributing to the final nonlinear fit.  Although unorthodox, there doesn't seem to anything to prohibit this approach outright.
Comment: So there is not only $\text{salary}$ and $\text{salary_group}$ but also the interaction? That is even more complicated than your title suggests.
Comment: @whuber Why not just use splines then if the goal is to better fit the nonlinear aspects of the data? (Assuming the usual square terms etc. don't achieve that either). I'm not saying the proposed model is always a bad idea, just that the proposed reason of "I assume the relationship is not perfectly linear" is a bad one. Tax brackets would be a more tangible reason for this model, perhaps there are others.
Comment: @DavidErnst that's not the only reason, because of non-statistical reasons I need to focus on simple, preferably linear-regression, model. Obviously there are better approaches for such data, but I'm simply asking what could go wrong if I used linear regression like this. The example I provided is made-up, but reflects important aspects of the problem.
Answer: As noticed by whuber the model I described seems to be just a variation of regression using linear splines. Such models are described, e.g. by James H. Steiger on those slides or on those notes by Frank Harrell. The model can be thought as a piecewise regression
$$
E(Y|X) = \beta_0 + \beta_1 X + \beta_2 I_{\{X>a\}} + \beta_3 X \cdot I_{\{X>a\}} + \dots
$$
or regression using linear splines
$$
E(Y|X) = \beta_0 + \beta_1 X + \beta_2 (X-a)_+ + \dots
$$
where $a$ is a knot and $(u)_+$ takes value of $1$ if $u$ is positive and $0$ otherwise.
So it seems that this problem reduces to asking Is there a problem with multicollinearity and for splines regression?


How many wandering black holes are there in the milky way?

Question: I have attempted to research this topic due to curiosity, but I have yet to find a credible answer, the best I could find is this article, which has no listed sources, and the author has also done similar "click bait" style headlines with little to no evidence.
Comment: The UK's Express newspaper strikes again !  Click bait is a good word for it. :-)  [This article on the Science News website](https://www.sciencenews.org/article/we-share-milky-way-100-million-black-holes) quotes it as 100 million.  As we're not sure how many stars are in the milky way, the black hole estimate is very rough ( we think there are about 100 to 400 billion stars ).
Answer: Yes as StephanG said there are thought to be 100 million black holes in our galaxy composed of approximately 100 billion stars. Most of these are thought to be stellar mass black holes. Not the super massive black hole assumed to be at the center of our galaxy. Some references are:http://hubblesite.org/explore_astronomy/black_holes/encyc_mod3_q7.html and https://www.sciencenews.org/article/we-share-milky-way-100-million-black-holes.
Comment: Follow up question: do we have any idea what the mean mass of those black holes might me?
Comment: Well most of these formed as stellar mass black holes meaning they had a mass no larger than about 1.4 solar masses.  I don't know how they have grown since forming though.
Comment: The average mass of stellar black holes that have been measured is about 10 solar masses.
Comment: @RobJeffries do you have a source on that?
Comment: @Cursed1701 There is a straightforward table on the relevant wikipedia page, with sources to the original literature. https://en.wikipedia.org/wiki/Stellar_black_hole


RandomAccessFile over HTTP

Question: It's easy to open a connection to a remote asset using URL.openStream() which returns an InputStream. What about random access?
Answer: HTTP 1.1 allows retrieval of parts of a resource through use of Byte Ranges, but...

servers are not required to support it
you will incur extra overhead due extra request/response headers, (possibly) establishing extra network connections, etc.
Answer: True random access is not possible via http. You can simulate it though by passing a starting point as a paramater and return a stream that represents data from that position onwards.
For example this is how progressive HTTP download works (e.g. YouTube video seek).

RandomAccessFile over HTTP


Charging 12V/4A battery

Question: Can I charge a 12V/4Ah sealed rechargeable battery with a 13.5V/500mA charger? If so, how much time would I need to charge it to 100%? If not, how can I charge the battery?
Comment: What's the capacity of your battery? Or do you mean 4Ah instead of 4A?
Comment: I think the OP means 4Ah. It's so annoying like when people say the data rate is 4Mbit or say "3MHz" is "3mhz" (double error)
Comment: What battery chemistry?  What chemistry is the charger designed for?  Do you have datasheets that you can provide for both battery and charger?  It's really hard to help you based on the limited information you've provided.
Answer: A lead-acid battery labeled 12V, 4Ah and a lead-acid charger labeled 13.5V, 0.5A can work together, likely.  Lead-acid manufacturers prescribe that the battery should not be charged at a rate greater than C/3.  A 0.5A charge going into a 4A battery is C/8.  Expect that it would charge in 8 hours.
Nevertheless, take precautions.  Charge the battery outside at least first few times.  Lead-acid batteries (abuse-tolerant that they are) can vent hydrogen when abused.
Further reading: BU-403: Charging Lead Acid
Answer: I would scrap the idea of using a recylced charger and just buy a cheap 12v lead acid battery charger. Full voltage on a SLA battery is 13.5v, in case you were wondering.
Answer: When fully charged, a lead acid battery has a voltage of 12.6V or so, when charging it's normal for that to hit 13.5V and the final charging stage can hit 14.4V (the higher voltage ensures that the battery is fully charged and helps prevent sulphation)
Answer: Using a different charger for what the battery is rated for is generally a bad idea. the battery is designed to be used with a specific charger that is rated for the same voltage and Amp Hours (Ah). You should not use this charger with this battery.

Charging 12V/4A battery


Drawing the DLS Grid for Alberta, Canada

Question: I have DLS grid data that I downloaded from http://www.altalis.com/products/property/ats.html (AltaLIS_ATS_V4.1_Coordinates data). But I don't know how to draw the grid on Google Maps. We have Meridian, Township, Range, Section and Quarter section. Could you please help me to solve this problem?
Comment: Ok. But can i customize the map because i have to show the  wells on the alberta area and i don't want search on the top that are showing during import the KML data and vertical menu on the left side.
Comment: Please include an example record or two of the data that you downloaded within your question body.
Answer:
Download the polygons (shapefile) instead of the coordinate data
which is just an ascii list.
Open the shapefile using QGIS as I
originally
suggested and Save
As to a kml file. Alternatively use Google Earth
Pro
(currently free), Shp2kml, or
another online
converter to do the
conversion.
Upload the kml file to Google Maps.


How to set resolution to below 360p for youtube in safari browser on ios 15

Question: To avoid unnecessary ads in youtube app i use youtube in safari browser which i installed with some ad blocker add ons.But lowest resolution possible in youtube safari is 360p,but i want to set this to 144p so that i can save my data(I mostly listen to music on youtube). So any idea on how i can set lower resolution in youtube safari ? (I know if i get youtube premium it will solve my problem but i don't want to take YouTube subscription)
Answer: If you are accessing YouTube through Safari browser, no - you can only choose the resolution YouTube shows you, and if it doesn't show anything less than 360p you are stuck with that. But there are some YouTube apps that allow you to always play videos at a set resolution. But they will have ads. (One way to partially block all ads on any app is to use DNS ad filtering, like AdGuard DNS, but it is also a privacy risk).
Comment: How is dns blocking a security risk? And YouTube ads are extremely hard to block with dns filtering alone, because the ads of the ads are numerous and change frequently.
Comment: Not per se a security risk but more of a *privacy* risk - any DNS server you use will automatically know all the websites / internet services you use. This is valuable data for advertisers / data brokers.
Comment: Oh yeah, I can see why that would be an issue from the AdGuard point of view. I was thinking of pi-hole, which increases privacy from ISP by using DNS over HTTPS and using cloudflare (privacy-focused).
Answer: If you are looking to avoid ads and also use YouTube mostly to listen to music/audio, you may consider getting a YouTube Premium subscription.
YouTube Premium lets you browse completely ad free, and lets you playback any video using the native mobile apps in the background mode even with the device screen locked in sleep mode.
When you turn off the device screen, YouTube app automatically and seamlessly transitions to only playing back audio, thereby also keeping your mobile data usage low compared to when playing back video. A good side effect would be that you'd be able to get more playback time due to reduced battery consumption.


Mashing&Sparging in a single vessel

Question: My brewing buddy has made a move toward grain brewing with the purchase of a brewing pot equipped with a thermometer, false bottom, and screen in the false bottom with an attached valve.  We can get to a mash temperature, add grain and hold temp with his burner unit if need be.  Do we then drain the wort into a second vessel, batch sparge in the brew kettle, drain it off too and then clean the kettle out and add the liquid back in to boil?  I'm just looking for the most efficient procedure here.  Recommendations?
Comment: Is it your only kettle you can boil in?
Comment: We have additional kettles we can use, but none big enough for boiling.
Answer: With one vessel and a grain bag, you're essentially doing the brew in a bag technique, popularized by our brewing friends from down under.
There are lots of you tube videos showing how to do this method, search for the term BIAB.  You will probably need to upgrade the bag you use, however, as the normal grain bags given with steeping grains won't be strong enough to pull out the entire amount.  (it's heavy with the water)  Some use paint strainer bags found at home improvement stores, but those can be prone to ripping after a few uses.
All grain brewing is just soaking grains in hot water for a time, then either taking the water off the grain, or taking the grain out of the water. In single vessel brewing, you're taking the grains out of the water, then proceeding to boil.
You mentioned a thermometer, do be careful not to snag the bag on that.  But with the false bottom, you should be able to heat your mash if it should fall too much after adding the grains.
Have fun!
Answer: If you have a boil pot and mash tun (two vessel system) you're limited to batch sparge. Use the boil kettle to heat the batch water, add to mash tun then lauter wort back to the boil kettle.
To fly sparge needs 3 vessels with the addition of a hot liquor tank.
If you only have the one vessel (mash tun) then you need to use a grain bag to remove the grain after the mash. Then the tun doubles as the boil kettle.
If your false bottom is a couple inches from the burner area you can apply heat during mash but it's really not recommended. Its difficult to get even heat through the mash even with stiring and often much of the enzymes denature near the burner.  Best to insulate well and use a strike water calculator for temp and rely on insulation to hold it, unless you have a HERMS / RIS.
Comment: We use a grain bag for the mash; move the wort to another vessel, take out the grain bag and heat water for the sparge then placing the grain bag back in to sparge the grain; remove the grain bag after sparging, put the first liquid back in and then start a boil?
Comment: Sorry to be so dense here, but we really are just beginners.
Comment: @Davemender that works. You will have an easier brewday if you had a second vessel to boil in, or use an igloo or ice chest for your mash tun.
Comment: Really? I sparge into buckets then move the HLT onto the burner and dump in my runnings.

Mashing&Sparging in a single vessel


Control Threads in window service using a thrid application

Question: I wrote a window service that performs some task using the threads.Now i am writing an application which controls the window service using the window service controller.There are also some threads which i want to control from this third party application.I tried to start/stop the threads using the database but it does not seems a proper solution.I think there must be some thing that would  support the controlling threads like window service controller from third application.
Any help would be greatly appreciated.
Thanks
Answer: You can override OnCustomCommand in your service to allow communication from your service controller trough ExecuteCommand.
You will only be able to send numbers between 128 and 256, but if you wrap that in an enum it should be pretty workable. If you need to send more data you could still fetch that trough the database after you send a command.

http://msdn.microsoft.com/en-us/library/system.serviceprocess.servicebase.oncustomcommand.aspx
Answer: What's worked well for me is to have a supervisor thread in my service that polls a database table for commands and in turn controls worker threads. The supervisor also writes status back to another table in the database.
The UI controller app polls the status table and writes commands to the command table. When the service responds to commands it echos the results back to the status table, giving positive feedback to the user.
I also use a third table as an activity queue that the worker threads write to and is displayed by the controller so the user can see what's happening. Limit how big the activity table can grow so that the controller doesn't have to always be running.
Guard the tables with transactions and this can run for a long time unattended.


Peltier module set up isn't cooling

Question: I have set up a Peltier module with an aluminium heat sink, cooling fan, 12V, 7Ah battery supply and thermal paste for the purpose of cooling water. At first, it performed well. It dropped down to 3.5°C in 2 hours. However, after the 2 hour mark, it had suddenly started increasing in temperature. I didn't move it or change the room temperature at all.
I decided to change the cooling fan to a liquid coolant, which didn't work either. I bought another set up, but this time I noticed the Peltier module and cooling fan would only perform separately when tied to the battery unlike before when both performed well even when the wires were tied together. So I brought back the previous set up, and tested it with the battery again. The same problem occurred.
Can anyone explain why this is happening and what I should do to get it to perform again?
Comment: please furnish a schematic diagram including all wiring and I'll have a go at it.
Comment: Sorry for the rough diagram, but that's essentially how I set it up.
Comment: A peltier will only produce a temperature difference of x between one side and the other, if ambient T is fixed then x defines the T of the other side.
Comment: does the battery still have power after 2 hours?  If it pulls 75 watts, that would be about 2 hours.
Comment: Please define "perform" - How do you verify there's a delta - T at the Peltier junction? (remember that if the "cold side" stays warm, the "hot side" will get hot if the junction is functioning. )
Answer: It is possible that there is a short circuit somewhere between the heat sink, the peltier slab, and the fan housing. Heat sink grease is electrically nonconductive but if a direct path gets formed through it then the device would stop working. I suggest you take the entire thing apart, clean it up, and test the fan by itself, the fan with the heatsink, the peltier slab by itself, and the slab with contact with the heat sink.
Comment: Thank you for the suggestion. I tested the slab and fan seperately, and they're both working by themselves. I then attatched the slab to the heat sink, and it also seems to be working. Similarly, the fan also worked with the heat sink. However, when I set the whole equipment up again, and attatched both the fan and slab's wires to the battery, the same problem occurred in which the fan stopped working.

Peltier module set up isn't cooling


What is this font style/type called?

Question: I can't find the name of this but see it in many places: basically an all caps with the first letter slightly larger than the rest, as below (circled in orange).
Answer: It's called Small Caps

In typography, small caps (short for "small capitals") are lowercase characters typeset with glyphs that resemble uppercase letters (capitals) but reduced in height and weight, close to the surrounding lowercase letters or text figures.1 This is technically not a case-transformation, but a substitution of glyphs, although the effect is often simulated by case-transformation and scaling. Small caps are used in running text as a form of emphasis that is less dominant than all uppercase text, and as a method of emphasis or distinctiveness for text alongside or instead of italics, or when boldface is inappropriate. For example, the text "Text in small caps" appears as Text in small caps in small caps. Small caps can be used to draw attention to the opening phrase or line of a new section of text, or to provide an additional style in a dictionary entry where many parts must be typographically differentiated.
Answer: These are small caps, although it's not so obvious in this font because the small caps are rather high relative to the x-height (height of the lower-case letters). Many book fonts like Bembo have lower small caps, at the x-height or only slightly taller.

It's possible the font didn't have properly designed small caps glyphs and the program making the document did "fake small caps" by just scaling down the capitals. Real small caps (first line) are designed slightly differently to capitals: they're more squat, wider and with less fine detail.
Comment: Yeah I noticed that too. The T and J are much thicker, and so probably the small capitals are just smaller type rather than proper small capitals.
Comment: Yup. Some small caps are higher though: traditional small caps are at x-height or only slightly higher; some FontShop typefaces have quite tall small caps. Fontwerk's Romaine, based on the work of Robert Granjon, has two sets: one low and historically appropriate (I think they're the best ones to use), one higher in case you prefer that. Mrs. Eaves, which I think introduced this idea, calls the lower small caps "petite caps", but it's not really a text font.
Comment: Just as a former wielder of the red pencil, if you're working with hard copy, the way to mark it is to put 3 lines underneath the "T" and 2 small lines under the "homas". Then indicate in the margin (or in your PDF comment box) "cap/sc" (minus the quotes). Whoever typesets the copy, or makes corrections, will know what to do. Hopefully. :)

What is this font style/type called?


Do you need a driver's license to travel in the U.S.?

Question: In the U.S., the law that governs motor vehicles is the National Traffic and Motor Vehicle Safety Act.
But according to the Constitution;

Freedom of movement under United States law is governed primarily by the Privileges and Immunities Clause of the United States Constitution which states, "The Citizens of each State shall be entitled to all Privileges and Immunities of Citizens in the several States.

Case #1: "The use of the highway for the purpose of travel and transportation is not a mere privilege, but a common fundamental right of which the public and individuals cannot rightfully be deprived." Chicago Motor Coach v. Chicago, 169 NE 221.
Case #2: "The right of the citizen to travel upon the public highways and to transport his property thereon, either by carriage or by automobile, is not a mere privilege which a city may prohibit or permit at will, but a common law right which he has under the right to life, liberty, and the pursuit of happiness." Thompson v. Smith, 154 SE 579.
Case #3: "The right to travel is a part of the liberty of which the citizen cannot be deprived without due process of law under the Fifth Amendment." Kent v. Dulles, 357 US 116, 125.
Case #4: "The right to travel is a well-established common right that does not owe its existence to the federal government. It is recognized by the courts as a natural right." Shachtman v. Dulles 96 App DC 287, 225 F2d 938, at 941.
So, are you allowed to travel in a motor vehicle in the U.S. without a driver's license?
Comment: "travel by motor vehicle" does not equal "operate a motor vehicle"
Answer: There is no basis for the view that requiring a driver's license is unconstitutional.
First, it's critical to realize that a right to travel has nothing whatsoever to do with licensing drivers. A right to travel does not in any way mean there's a right to travel in a particular way. Likewise, using a car does not mean you're traveling. Schactman is about the right to obtain a passport, which is a requirement to travel overseas. Kent is likewise about international travel.
Freedom of movement means the government cannot, without good cause (like being on parole), prevent you from traveling within the US, living where you choose, or working where you choose. Likewise, there's a right to international travel that means that without good cause, the government can't stop you from leaving the US or re-entering if you're a citizen. Requiring a drivers license to use public roads doesn't stop you from doing that -- there are other ways to travel.
The Thompson v. Smith decision explicitly supports the idea that requiring drivers licenses is allowed. To quote a more representative section from the case:

STREETS AND HIGHWAYS -- Right of Citizen of Travel and Transport Property -- Use of Ordinary Vehicles. -- The right of a citizen to travel upon the public highways and to transport his property thereon in the ordinary course of life and business is a common right which he has under his right to enjoy life and liberty, to acquire and possess property, and to pursue happiness and safety. It includes the right in so doing to use the ordinary and usual conveyances of the day. This right is not a mere privilege which a city may permit or prohibit at will.

STREETS AND HIGHWAYS -- Right of Citizen to Travel and Transport Property -- Use of Ordinary Vehicles -- Police Power. -- The right of a citizen to travel and transport property and to use the ordinary and usual conveyances of the day may, under the police power, be regulated by the city in the interest of public safety and welfare; but the city may not arbitrarily or unreasonably prohibit or restrict it, nor may it permit one to exercise it and refuse to permit another of like qualifications, under like conditions and circumstances, to exercise it.

AUTOMOBILES -- Drivers' Permits -- Arbitrary Revocation. -- The regulation of the exercise of the right to drive a private automobile on the streets of the city may be accomplished in part by the city by granting, refusing, and revoking under rules of general application permits to drive an automobile on its streets; but such permits may not be arbitrarily refused or revoked, or permitted to be held by some and refused to others of like qualifications, under like circumstances and conditions.

While Chicago Motor Coach doesn't seem to be available online, searching it finds other sites stating that the real issue was a commercial operator licensed by the State of Illinois, and whether Chicago, as a municipality within Illinois, could require them to also be permitted by the city. Another line from it seems to be "Even the Legislature has no power to deny to a citizen the right to travel upon the highway and transport his property in the ordinary course of his business or pleasure, though this right may be regulated in accordance with the public interest and convenience."
To quote more recent precedent, Miller v. Reed from the 9th Circuit (a federal court of appeals, not a state court) states that

The plaintiff's argument that the right to operate a motor vehicle is fundamental because of its relation to the fundamental right of interstate travel is utterly frivolous.   The plaintiff is not being prevented from traveling interstate by public transportation, by common carrier, or in a motor vehicle driven by someone with a license to drive it.   What is at issue here is not his right to travel interstate, but his right to operate a motor vehicle on the public highways, and we have no hesitation in holding that this is not a fundamental right.

(incidentally: Drivers licenses are not required by federal law. They are required by state laws.)
Answer: Yes, you are allowed to travel in a motor vehicle without a driver's license, as long as you are not driving the vehicle.
Comment: Your attention to detail is suitable for a law site, in my opinion. :-)
Comment: @dw1 My point is that a traffic code should not be seen as modifying a right to travel. The cases cited concern a right to travel. The question itself implies that it is about the right or privilege to operate a vehicle. The two are not the same. The question's literal wording clearly conflates the two,  asking if it is legal to travel without a driver's license, but whether it is legal to drive without one.
Comment: @dw1 I meant to add that I opened the question expecting it to be about TSA identification requirements or the like (e.g. http://www.dhs.gov/real-id-public-faqs).  I would also like to state for the record that an earlier comment should have ended with "not whether it is legal to drive without one", not "but...."
Comment: @phoog: The distinction is already being considered, mostly thanks to DUI laws. Apparently, if there's no steering wheel etc, then many states' DUI laws don't apply, as they require actual physical control of the vehicle. If there's a line to be drawn re: "operating" vs "driving", that would be the most likely one.
Comment: @dw1 as one who does not own and rarely operates a motor vehicle, but who regularly travels travels on public ways, I don't find the distinction to be a matter of "detail".
Comment: @dw1 This is a mistake that people in much of the US make quite frequently:  a colleague of mine from Texas once commented that we in the New York office must have a terrible time finding parking. Of course, none of us drives to work. A fellow student in college, in a conversation about underage drinking and driving, could not imagine a situation in which a teenager might be drunk but not have access to a car, but when I was teenager, I never had access to a car, regardless of my level of intoxication. I am merely trying to point out an error (in my opinion) of perspective in the question.
Comment: Perhaps I misunderstood. Traffic codes do not modify the constitutionally-protected right to travel between states, per se. They do regulate the mode of such travel, but don't deny it entirely (except, perhaps, if you're arrested for a code violation). It's a common misunderstanding to think the right to travel precludes the state from regulating modes of travel, so I can understand the Asker's confusion, if any. I'm not entirely clear on your concerns, though.
Comment: The question really does imply driving, although the term travel is used; otherwise, I just don't understand how one would even because think or suggest the possibility that your right to ride in a car,on a bus, or a train could possibly be limited just because you are unlicensed. I was very confused. In fact, when I first read the question, I almost thought they were talking about being a foreigner from a bordering nation like Canada or Mexico w/out a passport, except for the fact that you need a passport now for that as well.
Comment: @gracey209 the question may imply driving, but the cases on which it relies may not: the "right to travel" quoted from these cases could be derived from laws that predate the automobile.  My main point though is that the logical inference "right to travel = driver's licenses not required" makes as much sense as "right to free speech = radio broadcast license not required": having a right to do something doesn't imply that you have an unrestricted right to do it by whatever means you choose.
Comment: @phoog Right, all that is true. My point is, why would one question the right to travel (as a passenger in a car) without a drivers license. The fact the Q implies driving is beside the point. The point is, there are many people without licenses that travel across the nation (interstate travel) daily. The right to travel is absolute. That is why I say Im unsure why one would think because someone decided to be unlicensed they'd be unable to travel freely as a passenger in a licensed drivers vehicle. The fact that is appeared it was referring  to driving doesn't change the point of the comment.
Comment: I was agreeing with your comment, simply noting the question appeared to refer to driving, because otherwise the answer appeared somewhat obvious, since it was about a private vehicle and not a plane or a train or something (where you still don't need a license but you do need ID.)
Comment: @phoog An interesting question would be what would happen if the car is driving itself?
Comment: @TedTaylorofLife I imagine there will be lots of legal wrangling over the definition of "operating" a vehicle or "driving" one        as vehicles become more autonomous, but I doubt the right to travel will be of any concern in connection with that.
Answer: All 50 states have seen fit to enact traffic codes pursuant to their police power. Such regulation has not been found to infringe upon the right of Freedom of Movement, aka the "right to travel."
Licensing requirements began in the early 1900's:

"No court after 1920 found the right to travel sufficient to strike
  down a driver license requirement." Source

Here are a few federal cases supporting the right of states to regulate the highways:
Hendrick v. Maryland 235 US 610 (1915)

"The movement of motor vehicles over the highways is attended by
  constant and serious dangers to the public, and is also abnormally
  destructive to the ways themselves . . . In the absence of national
  legislation covering the subject a State may rightfully prescribe
  uniform regulations necessary for public safety and order in respect
  to the operation upon its highways of all motor vehicles — those
  moving in interstate commerce as well as others. And to this end it
  may require the registration of such vehicles and the licensing of
  their drivers . . . This is but an exercise of the police power
  uniformly recognized as belonging to the States and essential to the
  preservation of the health, safety and comfort of their citizens."

Hess v. Pawloski 274 US 352 (1927)

"Motor vehicles are dangerous machines; and, even when skillfully and
  carefully operated, their use is attended by serious dangers to
  persons and property. In the public interest the State may make and
  enforce regulations reasonably calculated to promote care on the part
  of all, residents and non-residents alike, who use its highways."

Reitz v. Mealey 314 US 33 (1941)

"The use of the public highways by motor vehicles, with its consequent
  dangers, renders the reasonableness and necessity of regulation
  apparent. The universal practice is to register ownership of
  automobiles and to license their drivers. Any appropriate means
  adopted by the states to insure competence and care on the part of its
  licensees and to protect others using the highway is consonant with
  due process."

(via Is There A Right To Travel In The United States?)
Answer: Normally, I would simply answer the question at hand, taking the words as they are posed and not questioning whether they were meant to say something other than their actual meaning. However, with regard to this question the author (if taken using the words as stated)  cites a variety of cases that stand for the proposition that travel is a right not a privilege, but yet simultaneously seeks to inquire  whether one can be required to be be a licensed driver to merely travel. This is odd to say the least, since the question itself seemingly answers the query. That perplexity makes me wonder (1) is the author talking about driving? If not, why ask what he/she already knows to be true, which is that you have a right to travel. There were a few answers already so I didn't bother to chime in, but since today the question lives on, I thought I would weigh in on some issues, if not an answer in an of itself.
Two things are clear: The right to travel is just that, a right, not a privilege. However, a driver's license is a privilege and not a right.
To begin, I think it is only fair to point out a couple of things that are (at least to me) a bit confusing about this question. First, when I initially read this question, I assumed the drafter meant "do you need a license to drive, not just travel", since the he clearly knows your right to travel is not merely a privilege but a fundamental right. As I mentioned, he has cited myriad cases in his very question that stand for this proposition. So can that really be the question?
Frankly, I think I would've assumed the question was intended to be about the right to drive, despite the use of the term travel, as I don't think there are many people who would entertain the notion that one may need to be a licensed driver in order to legally travel as a passenger. In the U.S., people travel every day that cannot drive for one reason or another. Clearly there are all manner of reasons for this... from disability, to  legal inability due to infancy, conviction, suspension, the elderly, and/or a whole host of other reasons; however, (almost) nobody would suggest that just because you cannot drive somehow limits your right to go somewhere when someone else is driving.
Whether the author meant drive vs. travel came up amongst a number of members both answering or commenting, however, the author never clarified his intention. Assuming people don't ask questions that cite the very answer they're seeking, I began thinking about it more.
Then I thought, did the author of this question, when choosing to use the term motor vehicle, intend to imply passenger travel in an individual's private motor vehicle, or, did he mean some other form of mass/public transit, or any/all of the above?
Next, I began to wonder about the use of the term drivers license. Is it possible the author was referring to identification (rather than a drivers license) in this scenario. Why? Because if the term license was intended, than the first issue is a non-starter  in that regardless of what you travel in/on, the analysis doesn't change - you have the right to travel without being a licensed driver. That is clear. Not only in the cases sited in the answers herein, but pursuant to article iv of the commerce clause, the right to interstate commerce necessitates the right to free travel. But where my confusion comes in, which is why I wonder if he potentially meant ID, is that again, in reading the question the author makes clear that he is well aware of the fundamental right to travel. However, you do not have an absolute right to travel without identification. Even under strict scrutiny, being able to identify a passenger, especially using public transit, having identification serves an overriding and legitimate public purpose (actually multiple purposes) and as such, would survive the strictest of judicial scrutiny.
Why am I pondering all of these clarifications?   Since taken at face value it's clear that the author already knows the answer to his question, I cannot help but wonder if we are missing the true meaning and there is really more to it that is either just missing or was somehow lost in translation.
I can see drivers licenses suffering from "the Kleenex" phenomenon. Just as people use Kleenex as synonymous with tissues, so do some use the word license interchangably with ID ("identification").  I remember as a college student heading out to the bars with my friends, and someone would inevitably ask "Everyone got their licenses?" This, despite the fact that many of our friends didn't drive, but they did have state issued identification cards so they could get into the bars! Many cities, like NYC, have full generations of residents who have NEVER had a license, because it's simply not practical to drive in a city that charges what most of us pay for a mortgage just for have a good parking space, there is nowhere to park if you drive away from your high-priced spot, traffic with the cab's is nuts, and the public transit system goes everywhere that you cannot walk to.
That said, it is difficult to assess who has the best answer when we don't know what was the intended query really is. This is all assuming he didn't just decide to ask a question he knew the answer to, and wanted to give his understanding of the law by citing cases in the question, so as to see if something unexpected would be written in an answer. Who knows! But that would be nearly as rare as thinking you could be legally required have a drivers license just to be a passenger in a car!
Anyway, If he meant do you need a license to legally drive, the answer is YES, and @Cpast and dw1 gave the best/correct answers IMHO, but those are mostly about regulating drivers (again, I too assumed this is what he meant, but only because of this discrepancy of form.
If he meant, do you need a license to legally travel in any moving vehicle, the answer is, "of course not" and his own question is the best source of (well, part of) why not.
But if the question was actually meaning to use the term Identification, then there is a whole other analysis to be done, and none of these answers are wholly adequate (and who will spend the time answering until we know!)
Comment: If it helps at all I did enjoy reading your answer :-)
Comment: If you Google some of the material from the question, you'll see that this line of reasoning is taken from several web sites that employ the same sort of fallacious logic applied to a carefully selected subset of laws and precedents that is used by many to argue that income tax is unconstitutional.  The OP has asked some other questions on this site that relate to income tax, too.  Your confusion about the question stems from not knowing that it is based on a crackpot attempt to prove a proposition that is in fact false: that it is unconstitutional to require drivers to be licensed.
Comment: ugh. I wish I knew I'd not have wasted my time.
Answer: I have been both on holiday and on business in many foreign countries, including the USA. If there was any need to have a driver's license to be allowed to drive in any of these countries, I would have expected the travel agency to tell me about it. Sure enough, they always tell me that I need a passport, and usually tell me whether some visa is required. I have never, ever been told that a driver's license would be required to travel anywhere in the world.
In addition, it would be completely unreasonable to deny children who are not old enough to have a driver's license, or senior citizens who are too old, or anyone with an illness that prevents them from getting a driver's license, the right to travel in the USA. Think about blind people who can't get a driver's license. Do you think they wouldn't be allowed to travel?
No, you don't need a driver's license to travel in the USA on airplane, river boat, as a passenger on a train or a bus, or a taxi, or as a hitchhiker, or on bicycle or on foot. I even saw a movie some years ago about an elderly man who lost his driver's license and travelled on his lawn mower ("The Straight Story", 1999). You don't have to leave your husband or wife behind if they don't have a driver's license, they are free to ride in a car as a passenger.
Answer: There is nothing fringe about exercising a right.  Operating a conveyance whether motorized or horse drawn does not require a license when traveling for personal reasons as it is a right and not a privilege.
It is when one drives for commercial purposes that a license is necessary and enforceable through statute.
If I were a jurist trying a case dealing with such issues, I would nullify any statute that misleads the public into thinking that the state can abrogate a right by turning it into a privilege.
Comment: This "answer" consists of four sentences: Opinion, unsubstantiated claim, unsubstantiated claim, opinion.  Can you provide any substance to back up the claims?
Comment: I think you're missing the point that moral rights and law are not exactly the same thing. An argument from moral rights belongs on Philosophy SE; here, we accept that the law is what it is, regardless of whether it satisfies the function of protecting rights, and the question is, what, objectively speaking, *does* the law say?
Comment: The state of Georgia has already met this issue by passing the Georgia Right to Travel Act of 2010.   If we study Maxim of law, the Constitution, civil law, and uniform commercial code all of which precede state statute ( public policy), it becomes apparent that you cannot contract under threat, duress, or coercion, and a constitutional right can not be converted into a crime. Remember a right is taken free and clear. You don't ask.  http://www.legis.ga.gov/Legislation/20092010/97280.pdf
Comment: For the record, Georgia did **not** pass the Right to Travel Act.  The bill died in committee and never became law.  https://www.legis.ga.gov/legislation/28916.  I couldn't find evidence that anyone supported it at all except its author, Rep. Bobby Franklin, who as one can see from [his Wikipedia page](https://en.wikipedia.org/wiki/Bobby_Franklin), took many positions that are not exactly mainstream.
Answer: Having a 'Drivers License' to 'drive' or 'operate' a 'motor vehicle' are all activities related to commerce. I hate it when lawyers try and deceive the general public by sticking to the correct language that defines these commercial activities and then suggests that people to not have a right to use or travel on the public roadways without permission. Notice the careful use of the words "motor vehicle" and "Drive" and operate". When these words are used in this context then the writers above are correct and their deception is clear. A license is a request for permission...hmmm...permission to do what exactly? Well to drive, of course, which is a commercial activity. If you purchase an automobile and use is solely for personal enjoyment and travel then the government cannot compel you to register it in order to obtain a license, to insure it or to even get an emission sticker or test for it. UCC Title-9, Section 102 clearly states that any item that is purchased for personal use or enjoyment is considered "consumer goods" and you cannot be denied its use by the application of taxes or registrations or licenses. This would diminish its value to the owner which would create an unlawful taking of your private property. You do not need to have a license to use it or to have it insured as well. These requirements would also be considered illegal takings by the government. Don't listen to these lawyers who have a vested interest in deceiving the public by using language designed to deceive. Study up and learn the system and then assert your rights and know how to protect them.
Comment: Sovereign citizen BS
Comment: You're wrong. Your entire argument resets on the invalid premise established in the first sentence. Show me the legislation that defines that those activities are exclusively commercial. In fact, it's so wrong that I'm placing a notice on it.
Comment: This answer is very wrong: driving is not necessarily a commercial activity. A license is not a request for permission; it is a grant of permission. The government can and does compel registration, insurance, and testing of automobiles just as they do with other dangerous things. Consumer goods are not exempt from tax, registration, or licensing on the argument that these reduce the value of the goods. (Also, if driving is commercial activity, how is a car a consumer good?) *Who* would consider these requirements an illegal taking?
Comment: Yes, very wrong, and it certainly merits the notice.  But remember that there are fringe theorists that espouse this sort of argument.  I think it's amusing and perhaps even occasionally useful to be reminded that this is out there.  In this case it adds "helpful" context to [gracey's excellent answer](http://law.stackexchange.com/a/3982/10).


Apple Mail with Gmail, via OAuth

Question: I would like to use Apple Mail on Mac OS to access my email account on Gmail.  How do I set this up, without using an app password (i.e., via OAuth)?
Unfortunately, I am unable to create an app password on Google, and my domain does not allow me to enable "less secure app access" for my email address.  So, I cannot use an app password.  Google has announced that "less secure app access" is not available for new users, and will stop being available for anyone on May 30, 2022, so soon everyone will be in the same position I am in -- soon, app passwords will not be allowed for anyone.
Google's help pages say I should use my Google Account to sign in, which I believe means using OAuth.  However I can not see how to configure or enable that in Apple Mail.  When I try to configure Mail using Mail >> Preferences >> Server Settings in the menu, it only provides a place to enter a username and password.  Now what do I do?
Answer: In Mail Preferences > Accounts, click the [+] and choose "Google"

This will bring up a Google sign-in page:

Apple Mail with Gmail, via OAuth


lost ubuntu 14.04 default login screen

Question: After trying to upgrade to gnome 3.12 unable to upgrade//
uninstalled gnome 3.12 however
lost ubuntu 14.04 default login screen
Plz help
Answer: This is more of a comment, but I lack the reputation...
If @Michael's answer doesn't work, it could be an issue with lightdm. If so, you can install gdm to get you logged in.
To Install:
<code>$ sudo apt-get install gdm
</code>
To (Re)configure /  switch back to lightdm
<code>$ sudo dpkg-reconfigure gdm
</code>
Comment: This worked well for me and I appreciate the additional info on how to return to lightdm (although I'm sticking with gdm for now - it's good enough and works :)
Answer: You can use tty pushing ctrl + alt + f6 that goes to tty, and then you just have to type:
<code>     sudo apt-get update
     sudo apt-get install --reinstall ubuntu-desktop
     sudo -i shutdown
</code>
and that might work, and have installed it again.
Comment: I tried this approach first, while it didn't fix my grumpy Ubuntu (14.04 LTS) I did learn something useful and it was well worth trying, thank you.

lost ubuntu 14.04 default login screen


Educational collectible cards

Question: I am looking for educational collectible cards. That is, physically similar to baseball cards but consisting of educational content such as famous cultural figures or bite-sized scientific phenomenon, etc. What kinds of product could I use for this purpose?
Comment: Hi! This isn't on topic as written - and the tag you created wouldn't be on topic here. I do think we can answer your general question (and I'll attempt to) but it needs rewriting to avoid asking for a specific product. It's okay to ask for how to teach something for example.  If you don't have a chance to edit it, I will do so in the next day or so.
Answer: I would suggest you look at either playing cards or at a bookstore for educational flashcards.
Playing cards are not uncommon to have something like what you're saying, especially in tourist areas they will have playing cards with the local whatever on them. There are other similar cards for animals or plants. We have penguin playing cards with facts about penguins for example.
Educational flashcards will generally be less collectible in intent, but still could be used that way.  Those are usually easy to find at larger bookstores.
Answer: Try Top Trumps cards. There are packs on dinosaurs, predators, history, etc.

Educational collectible cards


Help with bitcoin transfer to my ewallet

Question: Please Help..
I have been trying to withdraw my bitcoin off a website called mirminingpro.top I do everything it tells me but then at the end when I exchange coin it does nothing and I have a ewallet but I can't seem to figure it out..I tried cash app an it said I don't have enough to exchange but the site says  have 1.349223 bitcoins so I am so confused
Answer:
I have been trying to withdraw my bitcoin off a website called mirminingpro.top

That website is almost certainly a scam. The domain was only registered a few days ago

<code>WHOIS search results
Domain Name: mirminingpro.top
Registry Domain ID: D20230401G10001G_98928793-top
Registrar WHOIS Server: whois.nicenic.net
Registrar URL: http://www.nicenic.net
Updated Date: 2023-04-01T09:20:30Z
Creation Date: 2023-04-01T09:20:30Z
</code>

I am distrustful of any website that offers to mine Bitcoin for you. There's no honest business model that supports that kind of proposition.
In short I believe you are the victim of a confidence trickster, a conman, a criminal intent on deceiving you in order to steal money using fraud.
There is no realistic way to get back any money you have paid, any "earnings" or "gains" etc shown on the website are almost certainly fake. Continued contact can only lead to loss. Anyone offering to help recover money is almost certainly only trying to exploit you further.

I am so confused

It seems a standard technique of conmen is to deliberately confuse their victims and to panic them, for example by telling them that everything will be lost if they don't act quickly as the conman instructs. They want to overcome your rational decision making process and make you act in haste, in panic, without thinking things through.
I believe the best thing to do is to accept you will never get any money out of that site, discard any apps or accounts associated with this. Cease all contact with anyone recommending or associated with the site, put this incident behind you  and move on with your life.

How do I recover from a cryptocurrency scam?
How to tell if a cryptocurrency exchange or trading platform is trustworthy?
Comment: Thank you so very much. I really appreciate your help I thought something was wrong I mean I am no expert but I can do some as simple as a tranfer. I really thank you an appreciate your time an help.


Is there a way to normalize for both ways in Unity?

Question: I have a building, built in blender, that has been imported to Unity. And I flipped every necessary piece and calculated the normals inside in blender. However, since I made the rooms inside the building with just a single cube, it's only visible from one side like they're not visible until I go the way around. Is there a way to solve this?
Answer: You usually do not want your polygons to draw from both sides in a game.
If you're standing outside a building, you want to see the outside faces that point toward you. You don't want to waste time and GPU resources drawing the back side of the building.
Similarly when you're standing inside a building, you want to see the faces of the interior walls. You don't want to waste time drawing the outside of the building that's not visible from where you're standing.
This lets us cut down the GPU workload by almost a factor of 2 - a huge savings! (Imagine being able to take a game and double its fps rate without sacrificing visual quality on any visible surface)
If you configure your polygons to be drawn from both sides, you lose this optimization, so the GPU has to spend time drawing the inner faces of things only to draw over them with the outer face later.
Also, the mesh still has only one shading normal, so your shader needs to detect when it's drawing the "wrong" side of the polygon and flip the normal for lighting, slightly increasing the complexity of your shader.
For all of these reasons, I would strongly recommend that you keep your material single-sided. Interior rooms should have their own polygons, separate from the outer shell of the building (real walls have thickness, after all), that face inward. If you make these interiors a separate mesh, they can be culled entirely when not visible from the outside, if you set up your scene appropriately.
That said, if you want a dual-sided material, here's how you can modify the default new Surface Shader to accomplish it:

Add Cull Off to the top of the shader, just before CGPROGRAM. This says not to cull triangles based on their facing direction, so both the fronts and backs of triangles will be draw.

Add fixed facing : VFACE; to your Input structure. This is a special shader semantic that the GPU pipeline will populate with a negative value when drawing the back of a triangle, and a positive value for the front.

Inside your surf function, add o.Normal = o.Normal * IN.facing; to flip the normal for back faces.

Here's the full shader:
Shader "Custom/DoubleSidedLit"
{
    Properties
    {
        _Color ("Color", Color) = (1,1,1,1)
        _MainTex ("Albedo (RGB)", 2D) = "white" {}
        _Glossiness ("Smoothness", Range(0,1)) = 0.5
        _Metallic ("Metallic", Range(0,1)) = 0.0
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 200

        Cull Off

        CGPROGRAM
        // Physically based Standard lighting model, and enable shadows on all light types
        #pragma surface surf Standard fullforwardshadows

        // Use shader model 3.0 target, to get nicer looking lighting
        #pragma target 3.0

        sampler2D _MainTex;

        struct Input
        {
            float2 uv_MainTex;
            fixed facing : VFACE;
        };

        half _Glossiness;
        half _Metallic;
        fixed4 _Color;

        // Add instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
        // See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
        // #pragma instancing_options assumeuniformscaling
        UNITY_INSTANCING_BUFFER_START(Props)
            // put more per-instance properties here
        UNITY_INSTANCING_BUFFER_END(Props)

        void surf (Input IN, inout SurfaceOutputStandard o)
        {
            o.Normal = o.Normal * IN.facing;

            // Albedo comes from a texture tinted by color
            fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
            o.Albedo = c.rgb;
            // Metallic and smoothness come from slider variables
            o.Metallic = _Metallic;
            o.Smoothness = _Glossiness;
            o.Alpha = c.a;
        }
        ENDCG
    }
    FallBack "Diffuse"
}

Comment: You're the life savior! I don't know about Shaders or anything. I just made my school building. And oh, you're the one from yesterday, haha. I really am into modelling 3Ds and making my characters move. But since our school have something called "a final project" for year ending. I want to include a game login system on my little django server and I want to make the building my own school, so I could get more points for creativity or something. And I have been drag-and-drop'ing everything and copying every free assets and scripts. Thank you for your help, appreciate it!!


Is it bad to start and stop engine without driving?

Question: My spouse has decided to turn our garage into a workout area, so every day they pull my car out of the garage, do their workout, then pull it back in. Is all that engine on and off without actually driving anywhere bad for my car? Brand new 2021 Subaru.
Comment: When I need to move a vehicle a very short distance, I often pop it into neutral and do the "one leg push" while sitting in the driver's seat.  Of course, there is no power steering or brakes when I do this, so I have to be very aware of any slope or obstacles.  I don't necessarily recommend this technique to others, but it works for me.
Answer: If this is all that happens for months on end without any real driving, then yes, it would not be good for the car. However, if it is getting taken out and driven say once per week, there's no real issue. There is some wear/tear for starting a cold engine, but really it's negligible. The real problem is not running it until the vehicle is completely warmed up (engine/transmission/differentials) at least once in a while. That's only because seals dry out and the battery never really gets charged completely. Other than that, no, you aren't going to see any appreciable wear from what they are doing.
Answer: Unless the car is given a long drive or there is a battery charger connected, this will result in a flat battery fairly soon.
We used to say a journey of 7 miles at reasonable speed was needed to put back into the battery what was taken out by starting the car, and more in winter.
This "estimate" was given to customers who used their cars as shopping trolleys once per week for a total round trip of 5 miles, which led to them breaking down. Once we got them to add a weekly long trip there was not an issue.
This would come to light after a thorough check of the starting and charging system.
Comment: I guess the "7 miles" depends how easily the car starts. For example my own car lives outside and (in UK winter weather) usually starts on the second compression stroke even it has not been driven for a week. If you have to spend 30 seconds cranking the engine, that's a different story so far as the battery was concerned
Answer: I don't know if your car is Manual or not but if it is, I would consider just put the handbreak off and moving the car without turning it on and then putting the handbrake on again and that's it.