Allow root user to read, write execute, folder owner to read only, and everybody else to have no access to a folder ubuntu

Question: I'm making a "wargame" similar to the ones on overthewire.org. I have the root user, Ubuntu, that should be able to read, write, and execute files in a folder. I have one user per folder that should have read-only access to the files in that folder, and everybody else should have no access to the folder. What is the chmod command to do this? Thanks!
Comment: Can the read-only user also execute the files?
Answer: A better way, though not completely within the scope of an acceptable answer due to your requiring chmod, is to use (NFSv4 style) ACLs, which support much finer-grained permissions than the POSIX model.
While using "primary user" groups with only one user may work, as discussed they don't always exist, can have other users added, and can have the primary user removed.
Answer: You need to set the user to be the owner chown -R <username> <foldername> (-R operates recursively) then set the permissions to be read only for just the user chmod -R 400 <foldername>. Root will be able to read and write the files regardless of the permissions set. Now the problem you're going to have is that root won't be able to execute any files unless at least one execute bit is set so you're going to have to let the owning user also execute the files with chmod -R 500 <foldername>.
See here for a pretty good explanation of file permissions.
Answer:
I have the root user, Ubuntu, […]

I don't know whether you refer to the root user or to some regular user ubuntu which you consider a root user for the purpose of your game. This doesn't change much in my answer though.
In Ubuntu each regular user has their own group by default. Such group by default contains only its corresponding user. This makes the following trick possible:
sudo chown ubuntu:bob fileA
sudo chmod 740 fileA

This way ubuntu has all the permissions and bob (as the sole member of bob group) can only read the file.
You could do this the other way around:
# but don't! explanation below
sudo chown bob:ubuntu fileA
sudo chmod 470 fileA

but then bob as the owner would be able to chmod and give himself excessive permissions or to take them away from the ubuntu group, or to mangle with "everyone else's" permissions. Any answer that advises you to make bob the owner must consider this flaw.
You may want to set the directory ownership and permissions in a similar, yet somewhat different manner. You may want to do these changes recursively. Note that chown -R affects directories and files, that's why you need an approach that can tell them apart. See this answer. The approach works with chmod and chown and other tools. Adjust it to your needs.

To recursively give directories read&execute privileges:
find /path/to/base/dir -type d -exec chmod 755 {} +

To recursively give files read privileges:
find /path/to/base/dir -type f -exec chmod 644 {} +

Comment: not always the user accounts have their own groups. in many cases, users are in the *users* group. so this answer is a solution but only for specific cases.


Feynarts not working

Question: Update: I use FeynArts-3.7 with FeynCalc 8.2.0. When I enter **<<HighEnergyPhysicsFeynCalc(sorry I cannot write primes here)
I get a long list of error which I suspect is because of conflict between FeynArts and FeynCalc. Also When I write e.g.CreateTopologies[1,1->2]` it turns red and when I hold the pointer on it it says: *a symbol occurs in more than one place: One of the definitions is shadowed. * what is this and how can I fix it?
When I do as described in MSE I get the following error messages:
$LoadPhi = True; $LoadFeynArts = True; <<HighEnergyPhysics`FeynCalc`;
Loading FeynCalc from /Users/MyName/Library/Mathematica/Applications/HighEnergyPhysics
FeynCalc 8.2.0 For help, type ?FeynCalc, open FeynCalcRef8.nb or visit www.feyncalc.org
Loading PHI
WARNING! Your FeynArts installation is not complete or the version you have cannot be used with this version of FeynCalc.
FeynArts can be downloaded at www.feynarts.de
Loading FeynArts, see www.feynarts.de for documentation
FeynArts not found. Please install FeynArts, e.g., in
/Users/MyName/Library/Mathematica
and reload FeynCalc
FeynArts can be downloaded from www.feynarts.de

There's already a thread with a similar problem but none of the solutions there work for my case. I'm on a MacOSX Mathematica 10. This is what I do:
I install feyncalc by writing in Mathematica
Import["http://www.feyncalc.org/install.m"]

After this I can play around with feyncalc and it works i.e. DiracSlash[a], DiracTrace and so on. But I don't know how to make FeynArts work. I know that there is a FeynArts-3.7 folder in /users/myname/library/mathematica/applications/HighEnergyPhysics  where one also finds e.g. the folder Phi qcd Models etc.
When I try to do a very simple example like the one suggested in http://arxiv.org/pdf/1006.2231.pdf nothing happens: I write
top = CreateTopologies[1, 1 → 2]

(Mathematica only prints the text "CreateTopologies[1, 1 → 2]") and then
ins = InsertFields[top, F[4,{3}] → {F[4,{2}], V[1]}]

Finally
amp = CreateFeynAmp[ins]

Actually before I reinstalled everything something did happen, but that was an error as is described in this MSE link: FeynArts not working properly but now I cannot even reproduce this error.
So my questions are, how can one generate the simplest FeynArts example and if so it would be nice to have it working together with FeynCalc?
Answer: Provided that FeynArts was patched properly, which is mostly the case if the automatic installer is used, one can look at various examples involving FeynArts in the Examples subfolder of the FeynCalc installation:
<< FeynCalc`
FileNameJoin[{$FeynCalcDirectory, "Examples"}]

Feynarts not working


Why it is said that sharpening is always needed in digital pictures?

Question: Is it the sensor to blame? Because film-based pictures do not need sharpening.
Comment: @BBking The use of *unsharp masking* to make an image sharper in the darkroom has been used since at least the 1930s.   http://en.wikipedia.org/wiki/Unsharp_mask
Comment: Who says that? Sounds like B.S. to me, or a poor demosaic algorithm.
Comment: More exactly, I was browsing at the library and found a book that said so. I think the aothor was *. Fraser?
Answer: There's two mistaken statements in your simple question: first, that sharpening is always needed for digital photographs, and second, that it's not needed in film.
Let's start with the second. Film actually isn't fundamentally different here. Scanned photos often benefit from digital sharpening to match the output medium. But not even digital: the common "unsharp mask" digital sharpening technique is called that because it is based on an analog technique used with film.
It is true, though, that there are some things about digital sensors that mean that sharpening is a normal part of the workflow. One of these is that most digital cameras include an antialiasing filter to help reduce moire. That works by introducing blur, so sharpening counteracts that. Also, sharpening needs to be part of interpolation when using a Bayer-pattern sensor. Digital leaves you the flexibility of leaving that sharpening for the end of your workflow rather than locking it in. Depending on your sensibilities, though, you might decide that sharpening isn't needed at all.
But also, digital photography has ushered in trends that aren't related to needing sharpness in an absolute sense but are definitely related to an obsession with it. People tend to view images on computer screens, in high resolution, and when critiquing them, zoom in to 1:1 pixel view. This is like scanning over every photo with an extreme magnifying glass; in the film days, some people did this, but most people recognized that you could appreciate a photo without doing it.  Now, sometimes, people get an obsession with a certain sort of technical perfection in their photographs (often to the detriment of artistic qualities, or even more complicated technical qualities).
Comment: http://en.wikipedia.org/wiki/Unsharp_masking makes a good explanation of how unsharp masking works with film photographs.
Comment: I think its commonly said that you need to sharpen *for your target viewing size*, which may simply get understood as a general need to sharpen. This answer kind of says how to choose an appropriate sharpening radius: http://photo.stackexchange.com/a/9447/889
Comment: I don't get that part about film. I don't know a way to "sharpen" film photographs if not by manual retouching to enhance edges. When you use a scanner to digitize a film photograph it no longer is what was meant in the question, the way I read it.
Comment: @Cornelius - Thank you for the link. A great explanation there.


What review audit is this?

Question:
The review
This is a review audit. But the system shouldn't trick me to say this is a possible spam. I almost fell for it. Luckily, I pressed the vote count and found that this is an audit. Is this a bug or just some kind of audit trick?
Answer: The point of an audit is to make you stop and think. Or to document that you're not doing that.
It made you stop and think. So it did its job just fine.
(I should note that failing an audit on occasion is not a big deal, the issue is when you fail a lot of them.)
Answer: The OP and I have about he same reputation, so I'll guess that they are starting to do more review queue work, like I am. And for me the whole thing with review audits (that they exist, what their goal is, how they work) came almost completely out of left field (i.e. as an unpleasant surprise). It went from "Cool, they are trusting me more" to "Oh, they don't trust me."
I now see why review audits exist and agree they are a good idea, but think it would be good if they didn't come as such a surprise. Sadly I don't have any good suggestions, but I am posting this answer 1) so that OP realizes they aren't alone in this, and 2) letting mods know that this is an issue, albeit a minor one.
Comment: If you are attacking the review queues *honestly* and in good faith, you have nothing to fear from audits.  You will occasionally get the "wrong" answer (along with the condescending message that comes with a wrong answer), but mostly the audits will just pass you by.  Don't stress it. ;)

What review audit is this?


Will a Game written using HTML5 work on smartphones?

Question: I would like to write a game that could be played on smart phones and was wondering if HTML5 might be a way to write games to work on a wide selection of smart phones.
Answer: I just ran the HTML5 test:

My iPod Touch 2nd generation with iOS 3.1.3 scores 125 and 7 bonux points out of 300 in Safari. Of particular note to game development:

Full points in Canvas! Great for game rendering.
Supports the video element with MPEG-4 and H.264 formats
Supports the audio element with PCM, MP3 and AAC formats (great for bgm and sounds!)
Session and local storages are supported, as is Web SQL Database! (game save files?)
Application Cache is supported; I assume this feature would let you cache game data files (images and such) for faster loading. Sounds great to me!
No WebGL support.
No WebSocket either; multiplayer games will need to use something else like AJAX polling.

My Droid Incredible with Android OS 2.1 (+ Sense UI) scores 151 and no bonus points out of 300 on its built-in browser. Again, of particular note:

Full Canvas support
video element supported but all four codecs had X's on them. I wonder what formats it can play?
audio element, same thing as video - supported but formats all have X's.
Session and local storage and Web SQL Database all supported
Application Cache is supported
No WebGL or WebSocket
Web workers are supported, which were not supported on my iPod; these could be a good thing in game development for things that act in parallel -- perhaps AI?

Edit 2011/1/18: My Droid Incredible now has Android 2.2 and scores a 176 out of 300. Tchalvak (in the comments) got the same score with his Droid 2, so it seems to be common for the Android 2.2 browser. I also tried the Opera Mobile browser which got a terrible 72 (no bonus points) out of 300, but fully supports canvas!

So as you can see, the iPod/iPhone and Android are very much neck-and-neck and seem to support a decent range of HTML5 features. Canvas is great for 2D browser graphics and the audio element would probably be great for playing background sounds and music, and it's also really cool to see that both platforms support storage (though you could always just use cookies of course, depending on the size of a game save). So overall I'd say you should go for it. The numbers aren't everything; as wkerslake said "none of these numbers inspire confidence" but if you look through what is supported, it seems to be everything you need!
I say go for it! I wish you the best of luck.
By the way, you might want to watch for Vanthia. It's a browser game which utilizes canvas for efficient drawing. I got to play the closed beta and it was sure coming along! The developer has said very little for over half a year now, except that he is definitely developing it but just keeping things somewhat secret.
You could also get some ideas from Google's recent Pacman interactive logo. It wasn't very HTML5 but it sure was functional! It shows that you don't actually need HTML5 to make a browser game (and I think HTML5 is being thrown around as a buzzword far too much, just as AJAX was or still is). There is a github project with a deobfuscated, cleaned up version of the source that you can look through and play with.
Comment: My droid 2 global just scored a 176 (out of ?) on the html5test.  Full points for canvas.
Comment: Ah indeed, my Droid Incredible which now has Android 2.2 also scores 176 and no bonus points out of 300. I'll add it in the answer.
Comment: Also update on the status of Vanthia, the developer remains nearly silent but considering that he quit his day job for the game, I can only assume he will surprise us all with a huge release one of these days. I just wish he'd be more open about it.
Answer: HTML5 is a long way from being ubiquitously supported even in web browsers on PC much less phones.
These numbers are based on the html5test

IE8 on PC = 27/300
Chrome 5.0.375.125 on PC = 197/300
Safari 4.0.4 on PC = 207/300
Safari on iPhone4 = 185/300

None of those numbers inspire confidence
Comment: This answer would be more helpful if it had anything to do with the question.
Comment: I should be more specific. I don't see how IE8 has anything to do with the question at all. And I don't think monolithic html5test totals are helpful anyway. The question is whether the parts that *are* implemented are any good for games (the answer seems to be yes) and whether those games could really be expected to run on a variety of phones (I think yes again).
Comment: My experience with anything HTML related is that different browsers always do things slightly differently. Even when they all in theory support a feature, they may support it slightly differently. The html5test is useful guide for seeing the disparity of support across platforms. As long as you stick to a small subset of options that are supported by all the browsers you plan to work with, then a game just might work. I just don't have a lot of faith in browsers to properly build and/or maintain support for these standards. (See Chrome dropping its existing H264 support)
Comment: Today: Chrome 10.0.648.205... 288 points and 13 bonus.
Answer: It might seem a little late but I'd like to provide an update on the situation for HTML5 and the mobile browsers now that some time has passed. Lately, quite a few game engines have been developed that will produce HTML5 compatible games (see: Construct 2 and Game Maker Studio). Both produce OK performance but there has been notable issues with physics extensions and fast moving objects on some platforms. iOS still takes the lead when it comes to performance but Android has come a long way with the latest Chrome builds. It should be noted that Dolphin Browser on Android totes even 100% increase in HTML5 performance, as well! You can see a quick comparison done for a test below:

If you're looking to do manual optimization, there's some great advice listed here. Also, with HTML5 games becoming increasingly popular and allowed on sites like Kongregate and previously other flash exclusive game portals - there's no reason to be afraid of writing HTML5 based games anymore for a mobile device.
A few libraries exist as well to keep things easy to use on mobile, I've listed a couple below:
KineticJS
EaselJS
QuarkJS
Answer: as of July 2012, you can make smooth mobile HTML5 games. Check out this video
Answer: From the technical point of view it's certainly doable. There are some problems/pitfalls though:

There aren't much frameworks out in the open, so you'll have to basically write everything from scratch. From the renderer, to sound-handling, collision-detection. This can be a lot of work, depending on what you're trying to do.
You'll have to have a really good understanding of JavaScript. Some usual OOP practices won't work when using this Language. It's probably not the best choice for a game with huge amounts of code :)
Don't forget about performance. Smartphones are far from the performance of a typical Desktop-PC. You'll have to test performance carefully on different devices. It might also depend on the JavaScript-Engine (Browser) that is installed on the device. This isn't a HTML5 only issue of course.
Try to reduce the bandwidth needed for the game. Mobile-devices tend to have slower connections and sometimes people pay for the bandwidth they use. Try to use caching whenever possible.
Answer: Found a good post about iPad and HTML5:
http://mir.aculo.us/2010/06/04/making-an-ipad-html5-app-making-it-really-fast/
Also I would avoid heavy canvas drawing on iPad, for some reason it seems to be pretty slow.
Answer: You can use PhoneGap Build:
Just upload a zip file with the HTML5 code and it will give you the application for: Android, iOS, winphone, Blackbarry, Symbian ..ecc..
Comment: You'e a little late on this one. ;)
Comment: @CameronFredman Because HTML5 was finished in August 2010 or because moderators stopped closing similar questions?


Mitosis versus Meiosis I: What's the difference?

Question: At the end of mitosis, one cell has divided into two diploid cells. But at the end of meiosis I, there are two haploid cells. How are the two processes different to produce these two types of cells?
Answer: At the start, all the cells are 2n, diploid cells. By far the largest difference between meiosis I and mitosis is that mitosis results in genetically identical, diploid somatic cells. Meiosis, in it's entirety, results in gametes of haploid genetic information, but the genetic information is not identical due to crossing-over events that happened during meiosis I.
What you should also note from the figure: Each chromatid represents 1 DNA molecule. In mitosis, the cell will begin with 4 chromosomes and 8 chromatids. After cytokinesis, the somatic cell will have 4 chromatids and 4 chromosomes. This propagates during the next round of mitosis. In meiosis: The cell starts with 8 chromatids and 4 chromosomes. After meiosis I each cell has 4 chromatids and 2 chromosomes. After meiosis II, each cell has 2 chromatids and 2 chromosomes. You're halving the amount of genetic material each round of meiosis, and this can't be propagated indefinitely.

Source: Tortora, GJ (2008). Principles of Anatomy and Physiology. 12th ED.
Comment: Where have you found this figure?
Comment: @Ana Wiley library system, [source link](http://higheredbcs.wiley.com/legacy/college/tortora/1118345002/hear_audio/ebook/c03/tortora9781118345009c03xlinks048c.html). It's Tortora "Principles of Anatomy and Physiology," 12th ed.
Answer: the difference with easy way that the arrangement of chromosome on equatorial plate in metaphase
1- in mitosis all chromosome arrange on equatorial line randomly and single  so when it separate in anaphase separate to chromatide ( all chromatides), and each cell have 2n
however
2- in meiosis 1 chromosome arrange in duple or couples so when it separate as one chromosome , and each cell have n only
i hope it is useful for u
Comment: This doesn't make any sense


timeouts (ERR_CONNECTION_RESET) on seemingly random files after upgrading to HTTPS

Question: I have a WordPress site on a managed host (discountasp.net) that has run for several years. A few days ago I upgraded the managed site to use https by installing an SSL certificate (the actual installation was done by discountasp.net). As part of the troubleshooting so far I have upgraded to PHP 7.0 and WordPress 5.6.
Now, when loading any WordPress page, including the admin login page, I get random timeouts on various files. If I look in Chrome dev tools, I see that many files load immediately, but one or more time out.

In the example above, the file is jquery.js, but other files often fail to load also, especially .css files. Note that in the example above, it is the wp-admin page that is failing to load. I have also renamed the wp-content/plugins and wp-content/themes directories, so I don't believe any plugins or themes are involved here. So I believe all I'm trying to do here is visit the login page for a newly installed WordPress 5.6.
I can't tell if this is a problem in WordPress or a problem with discountasp.net. So far discountasp.net tech support has not been able to say anything useful. As I say, this site ran for years without trouble until I installed the SSL certificate. And that's the only change I made, so presumably that's what's making these files fail to load, but I don't understand why.
Also, I did trying adding these lines to wp-config.php.
define('FORCE_SSL_LOGIN', false);
define('FORCE_SSL_ADMIN', false);
define( 'WP_HOME', 'http://www.integratedinsightsconsulting.com/' );
define( 'WP_SITEURL', 'http://www.integratedinsightsconsulting.com/' );

That produced different behavior, but still broken. I was able to use the login screen to log in, but when the dashboard loads it times out loading some styles:
Answer: This was resolved by discountasp.net. Their note: The other issue is because the older IIS 7 server did not support TLS 1.2 protocol which your application required for SSL to work. I resolved it by migrating your site to our newer IIS 10 web server where TLS 1.2 is supported.


Are (electronic) CAD software related questions on-topic?

Question: I'm wondering whether questions related to PCB CAD software (such as EAGLE) are on-topic. Questions could relate to best practices, BOM generation, proper CAM export, etc.
Answer: Yes. According to our faq help center:

We feel the best Electronics Design questions have a schematic, links to pertinent datasheets or some source code in them, but if your question generally covers …

a specific electronics design problem
the theory and simulation of electromagnetic forces
a communication scheme
the writing of firmware for bare-metal or RTOS applications

Yours is a specific electronics design problem.
Comment: The question I have in mind relates to the specific problem of BOM generation with Eagle, actually. So it's more of a meta electronics design problem that's rather specific to Eagle. My feeling is that this is somewhat off-topic, but seeing that BOM export from Eagle is both widely need and badly implemented, I was thinking it may still make sense to ask.
Comment: @abey no, that doesn't matter. If you're doing something useful for an EE, it's on topic here. At least that's a good rule of thumb.


Is it possible to switch off the trackpad in OS X with a keyboard shortcut

Question: I'm using OS X almost entirely using the keyboard, and it helps to have the trackpad disabled most of the time. But I'd also like to be able to enable it every so often for individual tasks - is it possible to switch it off and on with a keyboard shortcut?
Answer: No way right now as far as I'm aware. I'd like to see an option to disable the trackpad while typing, for a user-selected number of ms after a keystroke.  That would solve the most irritating thing about the macbook for me.


ユーザ or ユーザー, which is more in use or is there no difference?

Question: ユーザ or ユーザー, which is more in use or is there no difference?
I see both of them in use, but is there one that is more correct than the other or is at least the prevailing standard?
a similar word is サーバ and サーバー.
Answer: From the point of view of the pronunciation, ユーザー is closer to the original English word, and that is the generally accepted form in ordinary life, especially among people who are not particularly related to information technology. However, limited to the information technology context, ユーザ is the form that is officially stated as the correct form, and official documents are recommended to be written as such. If you are interested in the detail, you may want to take a look at Japanese Industrial Standard Z8301 Amendment G Article 6.2c and Table G3. You can see a copy here: (logical pages 58 and 59).
Comment: this seems to fall inline with what Gerald had posted.
Answer: I work in IT in Tokyo and we use Salesforce and Netsuite, both are localised not translated. They use ユーザ、ユーザログイン、ユーザ名、ユーザパスワード etc.
Microsoft uses ユーザー and also サーバー.
Yes, it does look like consistency and style because I have read and used both ユーザ and ユーザー.
Comment: +1 for backing up with personal experience.
Answer: Wikipedia (ja) has a nice summary about omission of chōonpu ('─') character in general:

In the industrial sector, it used to be customary to omit the last chōonpu of loanwords, and it still is followed by some specific fields and companies.
Japanese Industrial Standard used to omit chōonpus by a certain rule, but it recently relaxed the rule to allow both omission or inclusion.
Even today, there is no nation wide standard on this matter.

(abridged translation by me)
From my personal impression, a person who uses ユーザ consistently sounds like he's been knee-deep in the industry for more than a decade, while ユーザー users belong to the generation Y who grew up living in the web.
However, this is an overgeneralization which I'll avoid until I'm pressed to make a judgment. In my own writing, I've used both depending on my mood, if it weren't specified by a prescribed manual of style.
Answer: Take whichever you want, but be consistent in your whole software/document/website.
My company often localizes Open Source applications to Japanese, and our rule is to not add ー if not necessary.
Also, Gentoo has its rule written like this:

GWN翻訳プロジェクトでは、ユーザやユーザー、コンピュータやコンピューターなど伸ばす、伸ばさない表記どちらもある場合については伸ばさない表記に統一することにしています

Translation: If both variations are in use, then do not add the final ー
Answer: Since nobody has given any hard data on the question of which of ユーザー and ユーザ is "more in use", here is the result of the Balanced Corpus of Contemporary Written Japanese (accessed via http://nlb.ninjal.ac.jp/search/)
ユーザー 2566 results (84%)
ユーザ   487 results (16%)

For サーバー and サーバ the bias is less prevalent
サーバー 1011 results (55%)
サーバ   813 results (45%)

Answer: Well, a quick google search gives basically 500 million ユーザー and 100 million ユーザ.
Wikipedia says both spellings exist.
I conjecture the same conclusion for サーバー and many English words that finish in "er" in English and are used in Japanese.
I would go for the "アー" version.


What is the usage of the "doctrine" tag?

Question: Do you guys think the doctrine is actually useful? If so what exactly should it be used on? Right now the questions tagged with it pretty much look like alphabet soup.
Answer: I do not think this tag is useful. If you want to tag a question doctrine figure out what doctrine you are trying to talk about and then tag it with the appropriate elements or doctrinal tradition it comes from.
A generic doctrine tag is useless.
Answer: Using tags as a folksonomy as in Shog9's answer, I can see what I think are valid use cases for the tag. We might easily have an expert on different doctrines of justification, and to them the tag combination justification doctrine would help searching for interesting questions.
In the general case, tagging by the name of the doctrine won't work, as in all cases the different doctrines don't really have names but are rather characterized by the name of the church they are used in. We can't really have lutheran-doctrine-of-justification.
Now, I will admit that my own use of the doctrine tag has probably been bad, as has my use of tags in general. I will try to correct my ways.


Running After Being Knocked Off Feet in the NFL

Question: In what year(s) in the NFL was the runner allowed to get up and run after being knocked off his feet, as long as they weren't tackled and held down? From memory, it only lasted 1 or 2 years because it caused lots of injuries. I think it was in the 50s but could have been in the early 60s also.
Comment: Hi Johnny, and welcome to Sports SE. Another user and I have made a couple of edits to your question to make it easier for others to find. If you believe that may have accidentally changed the meaning of your question, please feel free to roll back the changes.
Answer: According to the NFL (emphasis is mine), in 1955,

The ball is dead immediately if the runner touches the ground with any part of his body except his hands or feet while in the grasp of an opponent.

In 1956,

The ball is dead immediately if a runner touches the ground with any part of his body except his hands or feet after being contacted by a defensive player.

So it was a rule in 1955 and maybe before (the site does not make this clear).


If the Earth's core were made up of copper/other metals other than iron-nickel alloy, what would the magnetosphere be like?

Question: We know that our earth's core is made up of iron-nickel alloy, and it is spinning to create magnetic flux all around our planet to create our life-saving Magnetosphere. And this also influences our 9.8 m/s gravitational force, I think. So what if Earth's core (both inner-solid and outer-liquid) was made up of copper or any other metals? How would the magnetosphere and gravitational force differ from ours?
Comment: What if the Earth's rotation speeded up one hundred-fold, how would that affect our daily lives?
Comment: This question might be better suited to either SE World Building or SE Physics
Comment: I don't see the point of fanciful 'what if?' questions about imaginary worlds. I think questions should be about the real world we find ourselves in, not about some other world which we would prefer, or imagine in our dreams.
Comment: I'm imagining uranium.
Answer: On a quick approach:

Magnetism. The copper itself have a weak magnetism, so a copper core will not create a magnetosphere. Chek here or here.
Gravity. The Iron density is 7.874 g/cm³ and the nickel density is 8.908 g/cm³. Copper density is 8.96 g/cm³. So with those density data, the core will be heavier. (The actual core is supposed to have a 9.9-12 g/cm³ density) It is supposed that this additional mass will increase the gravity. What it is not well determine is the % of iron and nickel at the core, so, we can talk on probably a raising on between 5-15% the actual gravity force.

Regarding some other metals, it will depends on magnetism and density.
Hope it helps!
Comment: That's not quite correct. It's not the iron's magnetism that creates the earth magnetic field, but rather the electric currents that are flowing in the liquid iron. These would also be flowing in liquid copper.
Comment: Iron's Curie temperature, at which it loses its ferromagnetic properties, is 1043 K.  Earth's core temperature is around 6000 K.  So unless the Curie temperature increases considerably with pressure, the core magnetism is not due to iron's ferromagnetism.
Comment: It is not the iron's magnetism, for sure, is the motion generated by the core flows. Copper can not create it. Un the Curie temperature is related with the [pressure](http://przyrbwn.icm.edu.pl/APP/PDF/118/a118z5p012.pdf)
Comment: @Fred: But that's at around room temperature, and in solid materials.  Liquids at high temperatures might well behave differently.
Answer: As explained in some comments, it is the dynamo effect from the flow of liquid metal that creates the magnetic field, not the magnetic properties the solid metal might reveal under surface conditions. In fact, the liquid does not even need to be a metal; it can be any electrical conductor such as water containing dissolved salts. On smaller objects that cannot support a metallic core, a (weak) magnetic field could be generated by a subterranean water-based solution, as on Jupiter's moon Ganymede:

Computer models show Ganymede might have ice and oceans stacked up in several layers like a club sandwich. Scientists first suspected Ganymede had an underground ocean in the 1970s. The Galileo spacecraft discovered Ganymede's magnetic field in 1996, providing evidence to support the theory.
NASA's Hubble Space Telescope has found more evidence for an underground saltwater ocean, and evidence of a thin oxygen atmosphere on Ganymede.

Where we have a liquid metal core, one metal is more or less as electrically conductive and as fluid as another, so any molten metal would be capable of generating the necessary dynamo effect.
However, there is one subtlety. Under ambient pressure copper melts several hundred degrees Celsius lower than iron or nickel, or any of their alloys (alloying does not markedly depress the melting point with iron and nickel). If such a difference were to persist to Earth-core pressures, a copper-based core might solidify more extensively and leave less fluid for dynamo generation.
In the end, however, it is iron and nickel that are the most common metals likely to get into the core, in terms of both element generation and chemistry (copper is usually considered chalcophile, tending to form sulfides in the crust/mantle), so the mostly fluid iron-nickel core with a strong dynamo effect is what we have.
Answer: So, you are asking what our Magnetosphere would be like if the Earth's core was composed of something different than our current composition, and if it was copper, what effects would that have on it and the gravitational forces as well.
To answer there are 3 things that are most likely the most prevalent qualities of the Magnetosphere and core of Earth.

Consider that our current composition of inner and outer core is what allows our magnetosphere to be the most powerful electromagnetic field of any rocky celestial body in the known universe.
the magnetosphere acts as a shield, protecting our planet
from harmful solar radiation and charged particles
it is generated by the movement of molten iron in the Earth's outer core, which creates a dynamo effect that generates the magnetic field.

-To logic out the most possible answer based on these considerations:

If the Earth's core was composed of a different material, such as copper, it is likely that the magnetic field would be weaker or non-existent.

Copper is not a magnetic material, so it cannot generate a magnetic field. Therefore, if our core was made of copper, it is likely that our planet would not have a magnetosphere at all, or it would be much weaker than it currently is.

-About Gravity-
The gravitational forces on Earth would also be affected by a change in core composition because the strength of gravity is determined by the mass of an object, so if the Earth's core was made of a lighter or heavier material than iron, it would affect the planet's overall mass and therefore its gravitational force. However, it is difficult to predict exactly how this would affect the planet's gravity without more specific information about the new core composition.
In summary, the current composition of Earth's core is crucial for generating our magnetosphere and protecting life on our planet. If the core was composed of a different material, such as copper, it is likely that our magnetosphere would be weaker or non-existent, and this would have significant implications for life on Earth. Since the planets of our solar system formed around the same time, and considering the current condition of Mars and Mercury, one can assume atmospheric death by this point in our timeline. We literally have the perfect conditions for life to exist and life only exists due to the ELectromagnetic Fields of this planet. It is akin to God in all honesty, for without them, life would have to develop its own or be wiped off the face of earth.
Comment: In the generally accepted model iron doesn't create the Earth's magnetic field because it is intrinsiclly magnetic but because of, as you say, a dynamo effect.  As all this requires is a conductive fluid I don't think it follows that a copper core couldn't support an equivalent magnetic field.


Is there a good guide to convert a Bitcoin Core Wallet to Bitcoin Cash (on OSX)

Question: I got a wallet in Bitcoin Core.app version 0.14.2 on OSX. My last transaction is from years ago. How can I convert my wallet to Bitcoin Cash and what are the do's and don'ts? Basically I don't want to loose my coins. I heard that I could claim both new coins, its that true and how to do so?
Comment: If you want to claim both coins, download both softwares from https://bitcoinclassic.com/downloads/index.html
Answer: The first paragraph in the answer to this question applies in your case (possible duplicate question?). As you run a full client (Bitcoin Core) it's easy, as Bitcoin Cash has equivalent apps which are forks of this. I used Bitcoin ABC.
I used a separate machine for the Bitcoin Cash wallet. It may be possible to run both on the same machine (with different data directories - see this issue) but despite being called 'Bitcoin ABC.app' if you try and install it on the same machine as one with Bitcoin Core, you will get a message offering to overwrite the latter. Comments on how to accomplish this on one machine are welcome.

Backup Bitcoin Core wallet (~/Library/Application Support/Bitcoin/wallet.dat) to a USB stick (we'll transfer it later). This is the key do, which of course you will have done already
On the second machine download Bitcoin ABC from bitcoinabc.org. Currently it is the .dmg file in the osx directory. I expect they'll improve the UX to have an easy Mac-specific download button soon.
To get the blockchain to sync either just run Bitcoin ABC until it does (it'll download a chain similar in size to the Bitcoin Core one i.e. - 150GB+) or copy the legacy part of the chain (common to both coins) from the Bitcoin Core data directory. As OP comments, a Time Machine or other backup is perfect for this. I'll update this answer if someone can comment on exactly how to do it without one, as ideally you'll need most of the contents of the blocks and chainstate directories - up until just before the fork date; 1 August. You'd then only need to sync since then.
Overwrite the new wallet.dat file Bitcoin ABC created (same location as above) with the one from step 1.
With both apps synced you should now be able to send/receive BTC/BCC independently of each other from the relevant app - i.e you now own both. Should you come down on one side of the fence & sell all of either you can of course remove it's app, data directory & return the spare/borrowed machine.

In terms of dont's, you should ignore any advice to export/mess with your private keys - especially is someone offers to claim your BCC coins for you if you send your keys..
Comment: thanx so far. As step 3 I think I can use my Time Machine backup from `~/Library/Application Support/Bitcoin/` from one of the last days of July as a start for the Bitcoin Cash blockchain.
Comment: Perfect solution
Comment: Thanx MatzFan, This worked almost prefect.
Unfortunately on OSX Bitcoin Core.app and Bitcoin ABC.app both use the same config file and therefore both want to use the same data directory.
As a workaround I created an new User and restored there. Then Bitcoin ABC.app was stuck at block 478558.
I found this page about it: https://www.reddit.com/r/btc/comments/6r64gx/bitcoin_abc_client_sync_stuck_at_478558/ I deleted peers.dat, that worked for me! (Thanx hugobits88)
Now I got both apps running on my Mac.
The only problem is that both want to use port 8333 so they can't run at the same time.


Making Prosciutto with skin off (Wrapping in butcher paper?)

Question: Can I make prosciutto if my ham has no skin? Will this be a problem? I was going to try it anyway but the question becomes, do I just coat the whole ham in struto? And then do I wrap it in butcher paper or double wrap it in cheesecloth?
Answer: I don't want to discourage you, but given your other question on pancetta, it appears that you are both new to curing and lack the ideal curing conditions.  Making a prosciutto is much more challenging. Ideal conditions are necessary. To specifically answer your question, you definitely want the skin on.  Think about it.  A cured ham has to hang for a year or more.  You are going to want that layer of skin to help regulate the drying and protect the fat and meat. If it were me, I would either enjoy it fresh, or (depending on what you have) butcher it into smaller muscles, cure, tie, and hang those.


Load animations into custom engine

Question: for learning purpose of 3d animation, I picked blender to study.
So far I've exported .blend to .lua file that contains mesh data, bones, and animation data. My animation data is fcurve arrays based on keyframe.
I am trying to load this into an engine and run it.
I want to apply fcurve values on bones, however what I get is smashed animation. I am extra newbie to this, and I want to know what fcurve represent, how it should be used, and how I need to process the values to apply to bones.
Without setting fcurve to bones, it draws the model as I expected.
Thank you for the help in advance.
Answer: Blender's fcurve contains a collection of keyframed values, to calculate the value used on a frame in between two given keyframed values a bezier curve is used, each keyed point contains a left and right handle position that defines how the curve is calculated between keys. If you are only exporting the points listed in the fcurves data then you are missing the data for the frames in between.
You can have blender calculate the value for each keyframe instead of caclulating the curve yourself.
<code>for f in range(100):
    val = fcurve.evaluate(f)
</code>

Load animations into custom engine


Creating leaf shape illustrator CS6

Question: Trying to recreate this shape. I've got this far but would like to add smooth curvature my attempt is the purple stroked shape.
Comment: This shape is easily done manually with the Pen Tool. There are hundreds of tutorials out there on learning how to draw with the Pen Tool and @BillyKerr's recommendation from your previous question for the bezier game is excellent for practicing using and learning the Pen Tool.
Answer: Use the Pen Tool to draw the shape.  There's nothing particularly difficult here if you learn how to use the tool.  If you don't get the curves perfect first time, you can adjust them later using the Direct Selection tool to tweak the Bézier handles.
Example
Answer: You can create this by merely drawing a perfect circle. It's several extra steps but it takes absolutely no skill with the Pen tool.
To draw a circle, hold down the Shift key while dragging with the Ellipse Tool.

Obviously, you can start by merely drawing a path for the arc (step 4) if you are at least that confident with the Pen Tool.
Once you have the final shape, you can use Object > Envelope Distort > Make With Warp again using Flag to tweak the shape more...

Incase the image gets lost or broken...

Draw a circle
Use the Convert Anchor Point Tool and Click the side anchors, changing them to corner anchors
Double-click the Scale Tool - Non-Uniform - 150%H, 50%V
Delete the bottom anchor point
Object > Envelope Distort > Make with Warp - Flag +100% Bend
Object > Expand
Object > Ungroup
Double-click Reflect Tool - Flip Horizontal COPY
Double-click Reflect Tool - Flip Vertical
Manually move to align ends
Join end anchors
Answer: In case you want to make both 'edges' of the leaf look same, you can use pen tool and copy & rotation.

First draw on edge using any method which works best for you. There are many ways. I'd use a pen tool. You can use Object > Path > Simplify to make it a bit smoother or manually adjust the anchor points.

Then copy the same path, reflect it (using Transform tools) both horizontally and vertically and then drag it so it snaps to the end of 1st path. Then you can join them using Object > Path > Join option.

Note: I'm not very sure if CS6 has all of these features, especially snapping, but I just saw some tutorials about CS6 and I think it should work fine. But importantly, it's more of a practice and what works best for you, rather than using some particular tool or feature that exists or doesn't exist. You can spend some time on learning to draw with pen tool which will make things easier.

Creating leaf shape illustrator CS6


Does using Chrome bypass the Apple iOS gotofail bug ?

Question: Does the recent certificate gotofail bug affect me if I'm running version 6 of iOS, but only use Chrome as my browser?
Answer: No, Chrome on iOS is not affected by this bug as it doesn't use Apple's offical SSL/TLS library.
On Mac OS X, Chrome and Mozilla Firefox are not affected either.
Note that other applications than internet browsers are affected by this bug, in fact any application that relies on Apple's SSL/TLS library to encrypt data is affected (e.g. Mail, Calendar, etc.).
Comment: Are you talking about OS X, or both iOS and OS X versions? Firefox isn't available for iOS. Seeing as Chrome for iOS uses Apple's version of WebKit+JavaScriptCore, it would be surprising if they reimplemented the networking code to use their own library.
Comment: This is for iOS, I clarified my answer.


What is the root username and password for CUPS 2.1.0

Question: I don't remember creating one and I'm just trying to print in black and white.
Comment: Where do you need to enter username/password? Is there a dialog box of some kind?
Comment: Please consider selecting the below as a valid answer, it worked for me, I assume it did for you too?
Comment: @patrix: if you click on adming (localhost:631) it will provide a dialog box.
Answer: Normally you don't need to enter a root username and password to use CUPS. The error is likely to be in /etc/cups/printers.conf You could check the authorization entries in your printers.conf
Even simpler though is that CUPS.org recommends just using your normal admin username and password when asked for authorization:

Use the username and password for your computer.

You will need an account with admin privileges: most OS X computer owners have such an account, it's usually only in an lab or a company where you wouldn't have admin privileges.
I hope this works in your case, Esmeralda. If it doesn't please post some follow up information, such as your printers.conf file.


Connecting a Makita jigsaw (4351) to dry vacuum cleaner (Dyson)

Question: Could someone share their experiences with connecting a Makita jigsaw (22mm vacuum piece) to a regular vacuum cleaner (Dyson)? It appears that some people say it's just really impractical to connect a jigsaw to a vacuum? I suspect it might be a good idea to get a longer hose that's a bit more flexible than the average vacuum hose. What say you?
Comment: Suitable hose reducers and duct tape should do fine.
Comment: Anything's possible with enough duct tape!!
Answer: The main problem with using something like a Dyson or any other "floor vac" is that their filters (and warranty) are not made for sucking up a stream of sawdust or other "shop dust".  I imagine you can, and it should work fine, but you could clog up a comparatively expensive filter in a short time.
A "shop vac" has large filters made for exactly this type of dust and the filters are pretty cheap and easy to replace.  Some shop vacs will also accept bags for certain very fine dust that would quickly clog a pleated filter.
Your other issue is that attachments for power tools are going to be made for the standard sizes of shop vac attachments.  The only thing the Dyson has to connect to is its own included tools so it might not fit anything else without a clunky adapter.
Comment: Thanks for that great answer!
Answer: It won't work well and you don't need it

A jig saw work doesn't create the same dust and mess problem like other woodworking tools such as a sander, router, skill saw, etc. A jig saw does not create the same small fine dust like particles and it just doesn't have the speed and power to throw them very far. High speed tools work by removing much smaller pieces during each passing cutting blade and as a byproduct creates a lot of dust and can throw all of it a long way. Sanders of course work by exclusively removing very fine particles
Collecting tool dust is about pulling a lot of air, to get the larger particles it needs to also be a powerful pull of air. A household vacuum clear, while it can 'suck' well for household cleaning work, just can't move enough volume of air. From experience you probably know that you must get the detachable tool very close to the surface to do much good or work it into an area where the air is channeled by the surrounding surfaces such that it's almost as if it were an extension of the vacuum attachment. For a jig saw it would not be possible to get the tool close enough to the tool head to pull in the particles without interfering with your field of view and work area and there is no confined area around the saw blade to assist with the air flow. Or alternately, if the vacuum port was at a good distance then it would not be able to do it's job due to lack of power and volume to get any dust. And certainly there isn't enough power to get the larger particles

If you want to keep the area clean, simply sweep or vacuum up afterwards, easy peasy. If you are doing a cut that somehow requires more attention to keeping the area from getting particles on it, simply hold or clamp the vacuum attachment near the work, on lower in height if sloped so that the particles will slide towards the opening. Or use an assistant whose job is to running the 'cleaning tool' as you work. If your concern is dust and breathing it, again, it just won't create much dust in the first place like other tools and is not a concern.
Comment: Thanks for that great answer! I feel bad that I cannot give two answers the correct answer mark.
Comment: it could sill get messy if you're cutting a dusty material like drywall.
Answer: You need to let the dusty air go first through a cyclone filter which you will drive by your vacuum cleaner. Dust that the cyclone fails to capture will be trapped by the filter on the vacuum.
Comment: @Malte: It is not at all difficult to make your own device out of a bucket and scrap board that is almost as efficient at mechanical separation as one of those expensive plastic cyclone devices. See https://ericlippert.com/2013/11/26/thien-baffle/ for pictures of mine.
Comment: @Malte needs to be a rigid container rather than a bag otherwise it'll just collapse, and ideally at least as deep as the cyclone is high so the dust falls far enough away from the hole that it doesn't get get sucked into the vacuum if the hose gets blocked (at least for the off-the-shelf cyclones, Eric's baffle might not have that issue).
Comment: That's good to know, thanks! I came across those cyclone devices. I guess the cyclone devices has three openings. An inlet to the power tool, an outlet to the vacuum cleaner and then an opening for the dust with a bag (?) taped to it?
Comment: @EricLippert Awesome advice, ty! I was thinking of mounting a cyclone filter (https://www.amazon.de/gp/product/B07L2XJJMF/) onto a some plastic container.
Comment: @PeteKirkham Thanks for pointing that out!


Upgrading drive train for Cannondale Trail 6

Question: I am planning to upgrade cassette, rear derailleur, chain rings and front derailleur of 2016 Cannondale Trail 6
I am looking for 11-36 or 11-38 10 speed rear and 2 speed front.
Which model I need to select the cassette, derailleur and chain-ring set? I understand I have to change the shifters too.
Shimano XT range would be appropriate? My ride is offroad and onroad mixed daily and long rides (~60 KMs) weekends.
Any 10 speed cassettes will fit on my 8 speed free hub?
Or considering additional expenses, I am even considering 1X10 combination. with 33/32 T front with neat profile with no front derailleur . I feel when I ride with middle ring front and all the combinations on current 8 speed rear, is good. I guess my current middle ring could be 34. Will I miss the highway riding comfort with single ring in front? For lower spectrum I should be okay with 36T low end at rear
Comment: The free hub body width for 8, 9 and 10 speed cassettes is the same.
Comment: Current Shimano M8000 XT range is 2x12 speed and is a huge jump up from the mixed Acera drivetrain the Trail 6 has. If you want a new 10 speed system that's a step up [Deore M6000](https://bike.shimano.com/en-US/product/component/deore-m6000.html) will be fine. Note you can look up what size cassettes the derailleurs will accommodate on that page.
Comment: In addition to @ArgentiApparatus' comment: Shimano 11 speed cassettes also fit that freehub body. (With 12x things get more complicated: Shimano need another freehub, while SRAM has cassettes that fit the old freehub body as well as ones that need the xD standard.)
Comment: Hi, welcome to bicycles!  We try not to make product recommendations because this year's answer - even if there's no disagreement - may not be applicable in the future as models change and parts are no longer available.  That said, if you pick a component level comparable to what you have on your bike and stick to matching components from that line it should work.
Comment: All that said, you will definitely need to change your shifters too (you're going from 3x8 to 2x10) and you may even need to change your crank to get 2x working optimally.  (Of course I've also known people to keep their 3x crank and front derailleur/shifter and simply never use the lowest position, but you don't have access to as many gears that way, plus if you accidentally shift too far you will drop your chain.)
Comment: Thank you for the reply. To make it generic question, I am wondering whether a normal 10 speed cassette will fit on my current 8speed hub and without extension, derailleur medium cage will be able to shift to 10th ring (say its below 40T) ?
Comment: If you switch to a 1x system, better go for a higher spread of the cassette even though you think 11-36T would be enough, because with such a small range either 11T will be too big on the flats and descents (in case you have a small chainring - you would have to pedal really fast), or the 36T will be too small on steep ascents (in case you have a large chainring - you would have to pedal really hard). Also, when buying a crankset you should pay attention to whether you have a boost or non-boost frame (i.e. to your rear axle width) and buy the matching crankset, to ensure correct chainline.
Answer: You will need to change the rear shifter, also best to install new cables (inners and outers) to get the most out of the upgrade.
No need to stick with your existing brand. Microshift do a range of well priced products that would suit that bike very well.
In Shimano, XT quality is probably spending too much for that bike, Deore is practically the same quality  the same just a bit heavier and a few less features (e.g. brake levers on Deore miss out on the tool-less reach adjust and miss the bite ajust)
Answer: The latest Shimano Specifications Chart reveals which model numbers fit your parameters. Be aware that there are other model numbers which would work but are unlisted in this link as they are older models.  These can be accessed by using the  Shimano Product Info Archive and then selecting the appropriate PDF file.   Anyway, in general, double front Chainwheels come sized with 40-28T/38-28T/36-26T/34-24T ring combos and the top low sprocket on a Shimano 10 speed cassette is 42T which should be used in combination with a 10 speed rear derailleur having a GS sized cage.  Your current freehub will accommodate a ten speed cassette.  Additional considerations are that you will need a ten speed chain and possibly a new bottom bracket compatable with your choice of chainwheel.
Brand new components will run into the hundreds of dollars (probably not more than $300 at time of this writing in October, 2019).  Higher tier XT components will be more expensive than SLX or Deore will be of course.  Looking for used components either online or at a nearby bicycle coop will save some money.  There are some incredible values to be found out there, I can personally attest to that.   Along with the cost of componentry, there is a good deal of labor involved in a drivetrain upgrade.  Even if it's your own time and labor you intend to put into this project, it's worth considering.  I try not to overlook the time and effort required to find the appropriate parts and make sure they're compatible.
All of these "considerations" are why many will advise that shopping for a bike that is already equipped with what you seek ends up being a better value than upgrading expensive components.
Comment: considering additional expenses, I am even considering 1X10 combination. with 33/32 T front with neat profile with no front derailleur . I feel when I ride with middle ring front and all the combinations on current 8 speed rear, is good. I guess my current middle ring could be 34. Will I miss the highway riding comfort with single ring in front? For lower spectrum I should be okay with 36T low end.
Comment: @Anand I've stubbornly held to the notion I needed the range of a front triple. Ojectively assessing where and how I ride, I now realize this couldn't be further from the truth. With a 3x9 setup (42-32-22T up front), I rarely come off the big chainring up front and seldom use the 11T sprocket in back, so a 1x set up is what I'm going to next.  I think it's not unreasonable for me to have 36T up front and pair it with 11-42T ten speed rear.  Plenty low that'll give me and perhaps increase the frequency i use the high end.


Agile Accelerator (GUS) Source Control connector

Question: Since this is a managed package I am not able to dig into the code and figure out how stuff works but it appears that the SF Agile Accelerator AKA GUS has links into GIT and a couple of other source control options. Has anyone figured out how to do this?
Answer: I reached out to the devs on twitter and got a really good answer, https://twitter.com/aDroidman/status/613001785016320000
In short, its a web hook that populates those fields.


Is there a way to lower vassal integration cost?

Question: I just received a somewhat large vassal after defeating them in a war with my alliance. Now when I check the subject integration it says it costs 1105 influence but the absolute maximum I can ever reach is 1k ... is there a way to lower the integration cost or will I never be able to integrate them (in a non game modifying way)?
Comment: Declare war on his neighbor but don't come to his aid at first. Anything that makes the power gap between you and your vassal larger, should work.
Comment: That won't work in this case as that vassal has no border friction with anyone other than my empire and one of my alliance's member's. Besides, his fleet was completely destroyed by me and another war will reduce neither his naval capacity (I destroyed pretty much any of his space ports) nor his technology research. They're absolutely not powerful anymore, it's just that they have occupied quite some space.
Answer: The tradition Vassal Acculturation in the Domination tree causes the vassal integration cost to drop by 33%. In this case from 1105 to ca. 737, which is a reachable amount.
Comment: You might want to reword this if possible.  It's giving off a comment vibe.
Comment: I could be more accurate but other than that I'm not sure what you actually mean. I'd actually have added this as comment but I wanted to solve the question.
Comment: It's not that it's inaccurate, it's just that it's worded in a forum like manner.  It be more appropriate if you worded it as if you weren't the one asking the question.  Here on Arqade, we take format into strong consideration when reviewing posts.  Basically, I'm just trying to help you out for any future answers you may post here ☺
Comment: You could improve this answer by stating which tradition in which tree gives that benefit.
Comment: @TimmyJim & Philipp I changed my answer, thanks for mentioning.
Answer: There is bit of misunderstanding in your sentence:

Integration it says it costs 1105 influence but the absolute maximum I can ever reach is 1k

The integration cost can go well over 1k and indeed the maximum accumulated influence limit is just 1000, but you pay for integration on monthly basis -5 points per month until you'll pay it all, not a total number all at once. So it is not as hard to offset that cost by other means like declaring rivalries,  gaining support from factions, completing your ruler's mandate etc.
I was going to write here about the Vassal Acculturation, but according to wiki it has been changed - instead of reducing the integration cost by 33% now it provides Unity bonus:
Comment: You're right. I had assumed you needed the accumulated influence in order to start vassal integration, wich was a misinterpretation on my side. Yes, they changed the effect of Vassal Acculturation in 1.8. I will mark your answer.
Answer: The influence cost doesn't really mean much as you still gain influence.
It's very difficult to actually reach zero from 1k unless you have -7 influence gain for over 100 months which integration generally is but the influence cost is maxed out at -5 per month until the cost is reached.


Only one direction handle on corner point?

Question: I've been trying to find tutorials to help me understand direction handles in relation to corner points. The screenshot below shows a corner point and direction handle but it is only on one side? I was following a tutorial of tracing this image and in the video I could see two direction handles on this corner point but for some reason mine only has only has one direction handle.
Comment: Yeah this happens when you continue a line when you jus click and dont make a tangent for the other line.
Answer: Do it like this instead.

When you get to a corner anchor, click and drag out the curve handle, do not release the mouse click
Then, hold down Alt / Option
Drag to position the second handle in the direction you want to continue, release both the mouse click and Alt / Option key, and carry on
With the Direct Selection tool A click on the corner anchor point. You should see both handles

If you want to practice your skills, The Bézier Game is fun!  I have no affiliation with the site.
Answer: You can get both handles back with the Anchor point tool Shift +C
Just click on the point and drag
This tool can also move each handle independently


Phone interview with CTO of company for junior web developer position. What to expect?

Question: I started job hunting for my very first job programming a couple days ago and today I received an email from the CTO of one of the companies requesting a phone interview. This is my first tech interview of any kind so I'm feeling a little nervous. I know it's a bit of a general question but does anyone have any idea what could be fair game? Is there a good chance I'll get technical questions on the initial interview?
Comment: There's really no way to know--the title CTO means little without knowing the size and history of the company. Anything is fair game.
Comment: Have you tried google-ing your question ? I think you'll find plenty of helpful resources, especially given how general your question is.
Answer:
does anyone have any idea what could be fair game?

Everything is fair game.
If this is a large, established company, then expect high-level questions from a C-level executive.
If this is a small, startup company, and particularly if you would be working for the CTO, then expect more specific questions about you, your background, your abilities, etc. In smaller companies the title of CTO might just mean "the boss of the techies".

Is there a good chance I'll get technical questions on the initial
  interview?

Again, that depends.
If you are only being interviewed by the CTO (or if the CTO is the only technical person in the interview group), then you should certainly expect plenty of technical questions. You are after all interviewing for a technical position.
Comment: I'd agree with this, but I think it's incredibly unlikely that the CTO of a large, established company is going to be interviewing junior web developers, and certainly not as the first interview.
Answer: You are interviewing with the CTO, so expect technical questions. Expect to have basic questions asked of you such as "What is a RESTful query?" "What's the difference between a GET statement and a POST statement" "What is responsive design?" (90% of devices are mobile devices not laptops and desktops), etc.
The CTO most likely wants to gauge not only from your answers but the tone of your answers whether they are comfortable working side by side with you, whether communicating with you generates misunderstandings, etc.
Do not give answers that are longer than four or five sentences. You don't want to monopolize the interview time, given that the CTO wants to run through their list of questions to you.
As the interview ends, the CTO will most likely ask you whether you have any questions for them. Make sure to ask what it is that you must do in order to be considered successful in the position you are going for.


Encrypting twice with different modes?

Question: I was using a SOCKS5 proxy today (tunneled through SSH) and I began to wonder what the effect of encrypting twice (TLS over encrypted SOCKS5 in this case) would have on the security of the transmitted data. The proxy was using 256-bit AES in CTR mode, while the page I was viewing was using 128-bit AES in GCM mode. While I am not worried that this will be harmful at all, I am curious as to how much more difficult a scenario like this would make it for an attacker to break the encryption (assuming they could somehow bruteforce 128/256-bit keys).
Comment: How much more difficult than AES-256 in CTR mode? If the CTR is well applied, that question doesn't make much sense. Assumed that they could brute force 128/256 bit AES keys? You might as well assume that the attacker already has the keys, that would be a much more believable scenario.
Comment: GCM and CTR aren't really different encryption modes. GCM is CTR + (specific) authentication. So you are basically CTR encrypting twice with different key sizes. I.e. applying two (related but different) stream ciphers.
Answer: When you are e.g. sending TLS encrypted data over a SSH tunnel, there are two things in particular that should be noted:

The TLS handshake will only commence, once the SSH connection has been established.
The bulk encryption keys of TLS will be completely independent of the SSH encryption keys.

Since the handshakes and keys are completely independent, there is normally no reason to worry about any bad interaction between the two layers. The TLS data is no different from any other kind of data, from the perspective of SSH. The SSH connection is no different from any other kind of serialized physical connection from the perspective of TLS.
That said, in some corner cases there might still be security issues with such combinations, but only if you e.g are using the same broken random generator for the pre master secrets, etc.

I am curious as to how much more difficult a scenario like this would make it for an attacker to break the encryption (assuming they could somehow bruteforce 128/256-bit keys).

Most likely, not at all. If you picture yourself being targeted by an adversary with the ability to brute force 256 bit keys (which of course is not realistic), adding a second layer with 128 bit security will not increase the hardness in any significant way. This is (if not for any other reason) because the outer layer might be attacked separately. The TLS handshake is not encrypted, so a theoretical brute force attack on the SSH transport encryption will still only require a $2^{256}$ work factor.

Encrypting twice with different modes?


Length (Time) of an (non-vbr) mp3 file

Question: Im currently researching the mp3 format in order to build an mp3 decoder.
After some thinking I figured out that the simplest way to calculate the length of the song would be to divide the size by the bitrate (taking in account the size of the ID3 tag etc.), and transform the result to minutes. Using this method on a few songs I got accurate times.
I always assumed the time of the song is the length of the pure audio data, but in this method, frames are also "considered" part of the song (when calculating the time).
Also, the I understood that the audio data in the mp3 file is compressed, so when its decompressed the size of it will be larger of course, and then the time calculation seems un accurate.
Am I missing something here? because it just doesnt make any sense to me that the songs length is calculated with the compressed data and not the uncompressed ones, and frames which are a DWORD each are not ignored.
Answer:
I always assumed the time of the song is the length of the pure audio data, but in this method, frames are also "considered" part of the song (when calculating the time). Also, the I understood that the audio data in the mp3 file is compressed, so when its decompressed the size of it will be larger of course, and then the time calculation seems un accurate.

When a media stream, such as an MP3 file, is compressed with a constant bitrate, that bitrate reflects the compressed size of the data, not the uncompressed size. So your math is fine.
What will throw you off with this approach is metadata tags (e.g, ID3) -- those are part of the file size, but are not counted in the bitrate, since they aren't audio data. Luckily, those tend to be relatively small, so they won't affect your results much.

Length (Time) of an (non-vbr) mp3 file


How do gift card resellers prevent sellers from re-using pin and card numbers

Question: There are multiple gift card reseller sites that buy your gift cards and resell them at discounted price.  I was wondering how these sites prevent sellers from reusing the pin and card number after it has been sold (you can use the pin and card numbers online, or even at the store without the physical card).
Comment: I'm no expert.  But, I would venture a guess that they transfer them to a new gift card before payout and transferring it to the next customer.   Many stores have the ability to transfer gift card balances to a new card.  They could also assume that risk.
Answer: All the giftcard buying companies (like cardpool) are located in California because In the state of California all retailers that offer giftcards must refund giftcards for cash value or issue a new giftcard at no cost (California Civil Code Section 1749.5(b))
there is a 24-48 hour wait period for gift card buying companies to pay you.
So what they do is either get a cash refund or new card from the card that you sell.
Answer: The balance is determined by the card number and pin. On a physical card, this is stored as magnetic stripe data, in which case it can be captured and written to another card by a malicious person, however the balance would obviously stay the same, and couldn't be reused over and over. Online, The transaction is processed by a third party, or the business the card is for. Regardless, Somewhere in some database it says card xyz has a balance of 100.0 and when it is used, there is likely some server side side script that changes the value in a database making the card's value decrease, so it's easy to say after card xyz has no balance, it will no longer work.


Can Falcon 9's engines be ignited more than 4 times if there is enough TEA-TEB?

Question: SpaceX's Falcon 9 uses TEA-TEB as a ignitor for its Merlin engines. My question is if the rocket has more TEA-TEB, can the engine be shut down and restarted more than 4 times?
Comment: You get 4 as 1=launch, 2=boostback, 3=reentry, 4=landing?
Comment: @geoffc Yes, was just wondering if engines could be reignited more times or there are other technical aspects.
Answer: The engines can most definitely be ignited more than 4 times.
Every engine is separately test-fired at McGregor after it is built. The entire booster is then again test-fired at McGregor before being delivered.
In general, there will be a static fire of the fully integrated vehicle 1–2 days before launch.
So, even for a drone ship landing which has no boost back burn, the outer engines will have been ignited four times, the middle engines five times and the center engine six times.
And that is assuming the booster crashes on the first landing.
If the booster survives the first landing, the engines will be fired many more times; at least once for each launch.
Recently, SpaceX has launched Falcon9s without a static fire, so that reduces the number of ignitions somewhat. However, they always do a static fire on new boosters, and typically also on life leaders (i.e. on ones that are either not yet flight-proven or that are pushing the limits of reuse).
They might be swapping out engines when they see some anomalous readings, but we don't really know that. Unlike for Starships, this doesn't happen in plain view on the side of a public road, it happens inside the hangar.
However, even assuming that they have swapped some engines, it is likely that at least one of the engines on B1051 was ignited more than ten times.
Comment: Which suggests the FEMA (failure analysis) work done during design was aimed at a mean lifetime of more than 100 ignition cycles to meet reliability requirements.
Comment: The design target for F9 was 10 flights with minimal refurbishment. That implies at a minimum 30 firings for the center engine, assuming absolutely no test firings and only RTLS landings. As most landings are drone ship landings, and there are a couple of test firings as well, it's more like 40+. We have one booster that as flown 8 times, so it looks like they at least hit their target, maybe they even found during the last checkouts that they can go higher. Soot buildup / coking is going to be one of the major problems where they will at some point have to strip and clean the engines.#


CouchDB inaccessible on Amazon EC2

Question: I am using an Amazon EC2 "micro" instance as a testbed for a new project, one that is supposed to use CouchDB. Although the DBMS has installed correctly (via pacman; I'm using ArchLinux) and appears to start I cannot access Futon at all. This is in spite of me opening the necessary port in the security group for the instance.
Answer: Have you opened the appropriate port on your firewall as well?
Have you set the bind_address in /etc/couchdb/local.ini to 0.0.0.0?

CouchDB inaccessible on Amazon EC2


What hinges should I use for my overlay cabinet doors?

Question: I need help understanding how to choose the right hinges for my cabinet doors. I have new 3/4" thick cabinet doors, fully overlaying/sitting on the face frame of the cabinet box.  I do not want European hinges, and want the doors to open to approximately 180 degrees (open all the way back to the adjacent cabinet door).
What description do I look for in choosing the right hinges for this application?
Answer: If you don't want to use european style hinges, you need to use an overlay hinge such as this type

These can be found ast sites such as Rockler, or in many DIY centers.
Comment: Do I need to get one that says 3/4" on the packaging?  I notice many say 3/8", but have not found a 3/4" one.  Thanks.
Comment: On an overlay hinge, the thickness of your door is immaterial. What matters is how much it overhangs the frame opening. 3/8 sound like you are looking at inset hinges which are not correct. Thise are used with doors that are partially recessed into the frame.
Comment: I understand.  I will only look for overlay hinges (without inset).  Thank You for your help.


Cannot send ETH or DAO via Ethereum Wallet (Mist)

Question: I have DAO and ETH in my Ethereum Wallet. Every time I try to send it, I input my password and press send, and it sits there saying "confirming" for a few minutes. Eventually, it just reverts back to the password entry portion without doing anything, as though I never entered my password and pressed send. Also, it says can't estimate gas as you need 1 eth in your wallet. I have more than 1 ETH in my wallet. When I close the sending window, I get "transaction denied." Please help.
Answer: I'm assuming that you are using the latest Ethereum Wallet version 0.7.4. If this problem still persists after trying out the steps below, please download Ethereum Wallet version 0.6.2 and retry the steps below.
IPC Connection Problem
One of the problems with the Ethereum Wallet is a dropping of the IPC connection as documented in Github - Cannot load Ethereum Alarm Clock Scheduler Contract in 0.7.2 . Working in 0.6.2 . #515 .
When you start Ethereum Wallet, it will attempt to communicate via IPC to the geth Ethereum node instance. The IPC connection will work for a short time, and then fail. After about 5 minutes, the IPC connection will be re-established and you will be able to:

See the estimated gas
View the Contract READ and WRITE functions.

So, start Ethereum Wallet and wait about five minutes for the IPC connection to re-establish, then try executing your transaction.
To confirm if this is the issue you are experiencing, select the Develop -> Toggle Developer Tools -> Wallet UI menu. Then select Console in the top bar on the console to the right of window. You will see an "IPC Connection Error" message when the first failure occurs, and another message that the IPC connection is re-established after around 5 minutes.
Freezing
When you start the Ethereum Wallet AND you have loaded The DAO contract into the Contracts page, Ethereum Wallet will try to retrieve all the events arising from the tens of thousand transactions made to The DAO. Ethereum Wallet will operate slowly and sometimes freeze completely.
In this case, the solution is to leave Ethereum Wallet running for a few hours for the event synchronisation to complete. Then try executing your transaction.

See also Is the Mist Wallet stable?.
Answer: Consider accessing your coins in MIST using MEW interface and move them that way: https://www.youtube.com/watch?v=phht73IvUDI


Lunar lander, apollo 11, start position

Question: If i were to simulate a lunar module with: $x_0$, $\dot{x}_0$, $y_0$, $\dot{y}_0$. $x$ is horizontal position, and $y$ is vertical position. What would be appropriate values?
Comment: For Apollo flights they started in an eccentric orbit, with the lowest altitude a few hundred miles ahead of the landing site. They then used engine braking to reduce velocity (horizontal and vertical) to reach a landing. Do you want to simulate this "real" situation, or just a lander starting from a hover above a flat plane?
Comment: [Tales from the Lunar Module Guidance computer](http://www.doneyles.com/LM/Tales.html) shows a picture (figure 5) with numbers, in old units (feet per second, miles, etc.) might be good enough to start with. (I guess the angle of travel at the beginning of the powered descent was very shallow, almost horizontal, as they were braking from a stable orbit at that point.)
Comment: What exactly are you trying to do?
Comment: I've made a model in matlab, and some controllers. And to make it as realistic as possible(in 2D), I want the initial values to be as close to the real deal as possible.
Answer: I fetched the data I think you are interested in from JPL's Horizon application.
Eagle separates from the command module at 6:12 am on the 20'th of July:
CSM-LM separation        July 20 06:11:53
At the time of separation, the state vectors for the command module (at the time of separation the lander and command module presumably had the same state vectors, although I'm sure this is a very poor assumption, but at least it gives you something to work with) were as follows:
2440422.758333333 = A.D. 1969-Jul-20 06:12:00.0000 TDB
X:  -2.870360413463610E-04 Y: 4.500679223401464E-05 Z: -1.732432604852359E-05
VX: -6.504365861559985E-04 VY: -1.604671519715920E-05 VZ: -5.403321203240985E-05
The origin of the coordinate system is the center of the Moon and the time step 1 minute. Distances are in astronomical units.
The lander conducted several burns after separating from the command module, though, so if you want to model the descent of the lander, you have to take those burns into account.
Have a nice day!

Lunar lander, apollo 11, start position


Bartering Services

Question: My brother has a friend and her two children living with him. They get to live there based on the fact that she does farm work (provides a service). They have agreed that the services and rent equal out to be $1,000 a month. Accumulative $12000 a year. I understand that they both have to claim the $12,000 as income but does my brother also get to expense out his $12,000 as an expense to the Farm (Schedule F)? I have read the IRS site on bartering and can not get a clear answer...Any advice would be appreciated. Thanks!
Comment: I'm confused on a couple of points: Does your brother own the farm and the "barter" is between him (the owner) and his friend (doing work for him)? Or is the farm owned by someone else?  I'm also confused why two people need to claim the $12,000/yr, although that may be related to my question about who owns the farm here...
Answer: I'd suggest you talk to a tax accountant on this one. The combined taxes on $24,000 is a substantial amount of money, likely at least several thousand dollars a year, so anything you can do to legally reduce your tax liability could pay off big.
I would think that your brother could at least deduct any costs involved in providing the housing, analogous to costs for a rental property.
Also, bear in mind that for tax purpose you want to value this at the lowest value that you can justify. I'm not talking about fraud here, but giving yourself the benefit of the doubt. If you asked a realtor, "What is the fair market rental value for this property?", and she said "between $800 and $1100 per month", I'd write down $800, maybe $850.

Bartering Services


Currently running Ubuntu and Windows dual boot - will installation overwrite both partitions?

Question: I'm currently running a dual-boot system with Windows Vista and Ubuntu. I'm just wondering if the 'erase disk' option will effectively erase both operating systems.
Comment: yes it will. See [here](https://elementaryos.stackexchange.com/questions/2398/how-to-install-latest-version-of-elementary-os-along-with-windows-and-ubuntu), if useful :)
Answer: You can choose how you install elementary OS. In the installer, you will probably have these choices :

Erase Ubuntu and reinstall : Install elementary in the ubuntu partition
Erase disk and install : Take the full disk only for elementary
Something else.

Something else will bring you in a partitionning tool. You have to reduce one of your existing partitions and create a new one if you want to install elementary OS + Ubuntu + Windows (I personally don't recommend this, if you do, be careful with grub.)
Answer: "Erase disk" option will delete all the partitions on your harddrive, and create new ones for Elementary.
This means that Windows and Ubuntu would be completely removed, as well as any other data files you might have, and Elementary will be the only Operating System on your PC
Answer: Both the question and answers are old. But, if I understand them to today's version....on the install screen that lists the partitions on my hard drive there is a drop down selector under the list that lists the partitions again with the prompt: Device for boot loader installation:
is this where I can select the partition with the unwanted OS and that is where elementary will be installed?
Thanks for any help


Why not create your own encryption?

Question: I am wondering if AES-128 and the likes were once broken and if they were broken because people knew they were trying to break AES then why don't we create our own personal algorithm to encrypt the data and let the intruders wonder which algorithm was used?
Comment: there's a whole field of study dedicated to analysing and defeating unknown encryption algorithms, it's called cryptanalysis https://en.wikipedia.org/wiki/Cryptanalysis
Comment: This question already has a good set of answers here http://security.stackexchange.com/questions/2202/lessons-learned-and-misconceptions-regarding-encryption-and-cryptology/2210#2210 but basically the answer is that designing encryption algorithms is hard and you are very likely to do it badly.  Even experienced well funded people make mistakes with crypto
Comment: @user158421 just because you can't break it yourself doesn't mean someone else smarter than you can't either.
Comment: Let's suppose if I create something as simple as which swaps the bytes in a data file. How can anyone else read it without knowing if a swapping algorithm was used?
Answer: You could create a proprietary encryption algorithm, but to ensure that it is secure you would need to make it public, so it can be properly tested. (bar the secret key obviously).
Security through obfuscation is not recommended. This is the basis of Kerckhoffs's principle.
"The principle goes as follows: A cryptographic system should be secure even if everything about the system, except the key, is public knowledge."
Read more detail here; Kerckhoffs's principle
Comment: What I don't understand is why go through such complex process if you can simply hide the data through techniques such as swapping, altering, or mixing original data with custom data etc. ?
Comment: There are two factors at play here, the cryptographic algorithm, which will encrypt the information and obfuscation which is a blurring of the mechanisms used to implement the cryptography. You have to assume that the enemy will discover the mechanisms used to encrypt while still keep the information in the data secure. To do this the cryptography must be tested, to properly test it and for it to be trustworthy you should make it public. If it is for your own personal use then fine, go ahead, but how could you be sure that someone hadn't broken your encryption?
Comment: Even more basic than to ensure it is secure, in order to use it for communication (unless you are only using it to store your own private data) you are going to have to share the algorithm with your communicants.  Either you create one algorithm for each communicant or you basically make it public.  Good luck getting all your communicants to install your custom crypto software.

Why not create your own encryption?


Are there any guidelines on the use of speech in interfaces?

Question: I'm thinking about how the gender, talking speed and accent of the speech voice used affects user understanding.  (UK market) Examples of speech interface: SatNavs, Automated Telephone Assistance Services, etc.
Comment: This is a fairly broad question because (1) some of the guidelines for the use of speech in a UI will depend on the context of use, e.g., speech interaction in a in-vehicle navigation system will differ from speech in a telephone service, (2) there are many variables to be considered, e.g., the 'talking speed' mentioned above could refer to 'the speed at which the system speaks' or 'the speed at which the user speaks'. Is it possible to narrow the question a bit more. Otherwise, the answer you get might be too generic to be useful.
Comment: I was after information particularly on automated speech OUTPUT rather than human speech INPUT to an automated system.
Answer: Somewhat old paper, but has a decent starting point: User Interface Design Guidelines for Speech
When and how to develop a speech recognition application:

Use speech when the user's eyes and hands are busy or when the user is moving.
Train the speech recognition system in the user's work environment.
Iteratively evaluate and re-design the speech recognition application.

10 guidelines related to the software portion of the speech recognition user interface:

Keep small the number of words in the speech recognition vocabulary.
Keep short each speech input.
Use speech inputs that sound distinctly different from each other.
Provide immediate feedback for every speech input.
Keep the user interface simple.
Make error correction intuitive.
Avoid modes.
Don't use speech to position objects.
Use a command-based user interface.
Allow users to quickly and easily turn off and on the speech recognizer.

However, keep in mind that natural language processing has come a long way in the past couple years making it possible to have seamless voice interaction rather than just command based voice input.
Answer: Yes. In regards to research on which gender to use, I suggest you read a book called, "Wired for Speech" by Cliff Nass.
I work as a voice user interface designer and I've compiled some lists:

Understand your target audience before starting any design work.
Use the brand's persona for creating and playing prompts.
Use conversational language rather than treating the system as "information collector".
Try not to use "Please" on every single line.
Try not to use "Sorry" too much.
Understand your users' mental model and cognitive limitations when presenting information. For example, native English speakers often place new information at or near the end of the sentence, and this is where they often expect to retrieve it.
Use cohesion devices such as pronouns, discourse markers, pointer words, etc.
Remove words and phrases that can be supplied by context.

There are other conditions to think about such as error strategies.
What I often I see in a lot of automated systems, including virtual assistants is the lack of escalation on dialog error prompts. For example, I was interacting with a bot some time ago and when I said something out of context, it just responded with, "Sorry I'm not smart enough!"
Hmm…
First of all, never acknowledge you're stupid. It's OK to acknowledge you don't know the answer but admitting you're "not smart enough" is too much; even for a bot :)
Here's a way for dealing with escalating error prompts:

System:  Thanks for calling. How can I help you?
Caller:    Uhhhhhhh
System:  You can say – get order status, account information, or just say – it's something else.
Caller:    Get order status
System:  OK – what's the order number? If you don't have it, just say – I don't have it.
….

Simple eh? So not sure why a lot of these bots and systems miss this. A great user experience happens when you take the user back on track by guiding them.
Now you don't have to give all the details right away. There's another approach known as rapid re-prompt. This approach doesn't give away all the details but instead, the response is given with something simple, such as, "I'm sorry?".  Here's an example:

System: Tell me your date of birth.
Caller:  Well…
System: I'm sorry?

The disadvantage as you know is that the user is not getting all the information in details. The best place to use this is during open-ended prompts, such as 'How can I help you?' and the user is often not considering this as an error.
Comment: Useful to have the examples of structuring responses.   (On the subject of 'escalation' a system used by one of the government departments, shifts to sounding annoyed if you don't talk to it but sit there silently until it has to tell you which buttons to press on your keypad !).


What's the difference?

Question: Is there a difference between "no place to go" and "no place left to go"?
e.g.

There is no place to hide.
  There is no place left to hide.
Comment: Yes, there is a difference.  What do *you* think the difference might be?  Please add more detail to this question or it might be closed.
Comment: @Andrew it won't be closed if I delete it first ;) Actually, thank you, this is just what I wanted to know. I can't provide more info because of my poor English.
Answer: No place to go. There is no place, period. It does not imply there once was a place to go.
No place left to go. There was once a place to go and now there isn't one.
There used to be places or a place to go.
There's no sugar left. Meaning: There was some sugar and now there isn't any.
I do understand how it might be difficult to explain this if one has limited English so I went ahead and provided the answer.
Comment: Please edit out that bold '**is**' in the first sentence.
Comment: Looks better now
Answer: Is there a difference between "no place to go" and "no place left to go"?
Imagine you are stuck in a desert and someone says to you get out from there immediately. So you will say there is no place to go as its a desert.
Imagine you are travelling in some city for almost a month and you got bored and someone tells you to go out and explore the city more. What you will say is there is no place left to go as you are there for a month and each place you must have seen already.
I hope you get the difference.

What’s the difference?


Transcendental Idealism and past time

Question: According to Kant, time is part of the phenomenal realm.  What would Kant say about past events such as the big bang when no minds existed?  Would he say we can't know such things?
Answer: Your question is complicated because you take the big bang as an example, which marks also the "beginning of time" and is thus more problematic. In fact, the first of Kant's famous antinomies is dedicated to it.
However, always keep in mind that Kant was a transcendental idealist, not to be confused with an "esse est percipi"-idealism á la Berkeley.
As to the more general question: Is it possible in Kant's view to conduct history as a science on a geological/development scale? – The answer is yes.
Kant was acquainted with so-called natural history his time, i.e. the work of Linnaeus and Buffon. Kant introduced an important distinction between "description of nature" (Naturbeschreibung) and "history of nature" (Naturgeschichte). Only the second can aspire to be science proper. As Kant writes,

if by the [description of nature] one wanted to understand a narrative account  of natural events to which human reason [Vernunft] cannot extend, e.g. the first appearance [Entstehen] of plants and animals, then to be sure […] this would be a science for gods, who were present at the time of creation or who were themselves the creators, and not for human beings. A history of nature would, by contrast, concern itself with investigating the connection between certain present properties of the things of nature and their causes in an earlier time in accordance with causal laws that we do not invent but rather derive from the forces of nature as they present themselves to us, pursued back, however, only so far as permitted by analogy. Indeed, this would be of a kind of history of nature that is not only possible, but one which is attempted frequently enough, as, for example, in the theories of the earth formulated by careful natural scientists (among which the theories of the famous Linnaeus also find their place).
I. Kant, Ueber den Gebrauch teleologischer Prinzipien in der Philosophie, 1788.

This paper contains a more detailed discussion:

Phillip R. Sloan, Kant on the history of nature: the ambiguous heritage of the critical philosophy for natural history, Stud Hist Philos Biol Biomed Sci, 37(4), 2006, pp. 627-48.
Comment: Kant says, "A history of nature would, by contrast, concern itself with investigating the connection between certain present properties of the things of nature and their causes in an earlier time...".  What does Kant mean by earlier time?  Isn't time something that the self pre-organizes in order to have experience?  "Earlier time" only seems to make sense if time is thought of as outside your phenomenal realm.
Comment: @user3306 In order not to get confused: "Time is part of the phenomenal realm" is not really correct, nor does the self "pre-organize" time. Kant understands time as the production of a temporal order of appereances through the application of the category of relation. This application results in an objective time-order, which [is different from our subjective time-order](http://goo.gl/N9XKF).

Transcendental Idealism and past time


Making pen and ink corrections on a UK visa form?

Question: After printing out a UK visa form, can you cross out planned arrival date with a pen and write a new one?
Comment: If someone is struggling with 'affect/effect', the phrase 'dog's breakfast' might be lost on them... (he means 'a mess').
Comment: Not 'effect', 'affect'. And it doesn't affect anything. OK, as long as you don't make a dog's breakfast out of it.
Comment: Yes, very common.
Comment: So it doesn't effect ?
Answer: Advice appears to suggest that as long as passport and visa applications are neat, very minor crossed out errors won't make any trouble;

Complete the form in capital letters with a black ballpoint pen
Write only within the white boxed areas
Leave other areas of the form blank.  Do not strike through or otherwise mark them
If you make minor mistakes you can black them out with a pen. Do not use correction fluid.

Source - visacentral.co.uk
These guidlines are similar for all similar applications - the most important point is do not use correction fluid!
As suggested here,

mistakes can lead to misery so getting it correct first time is a must and imperative as first impressions do make all the difference, an application with no mistakes looks better than one with plenty.

So, if it's one letter wrong, I'd suggest using a pen to neatly correctly - but make sure it is clear.
If the mistake is much bigger, I would print a new form and start again.
Answer: The consensus on the internet seems to be that you can make corrections to a paper UK visa application form. Obviously you'll want to keep the correction as neat as possible, making sure that the correct information is readable and the incorrect one is clearly crossed out. If in doubt, I would advise you to get a new form and start over.