PayPal IPN Simulator Bad Request

Question: I´m trying to test my IPN listener with the IPN simulator, but I´m always getting "Bad Request" error.
I´ve already see this answers:
PayPal IPN Bad Request 400 Error
Paypal SandBox IPN always returns INVALID
For my web I´m using the code you can find here: http://www.markstraley.com/Code/PayPalIPN
Thinking in the others answers, maybe there is something wrong in this code, but I don´t know what, if there is something wrong:
<code>HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url);
webRequest.Method = "POST";
webRequest.ContentType = "application/x-www-form-urlencoded";

//must keep the original intact and pass back to PayPal with a _notify-validate command
string data = Encoding.ASCII.GetString(parameters);
data += "&cmd=_notify-validate";

webRequest.ContentLength = data.Length;

//Send the request to PayPal and get the response
using (StreamWriter streamOut = new StreamWriter(webRequest.GetRequestStream(),System.Text.Encoding.ASCII))
{
    streamOut.Write(data);
    streamOut.Close();
 }
</code>
I´ve thought in this code section, because I saw that the other asnwers was solved with the header of the request, but I don´t know if this code is correct or not for PayPal. I´ve already seen the paypal code examples, but all of them are with VB or webforms.
Thank you for your help.
Note: I have my app in a server to test it, I´m not trying to call my localhost from the IPN simulator.
Answer: At the end, I simulated myself the post data from PayPal using the app "Advanced Rest Client" for Chrome: https://chrome.google.com/webstore/detail/advanced-rest-client/hgmloofddffdnphfgcellkdfbfbjeloo
I wanted to tested from PayPal, but for now it's enough. Thank you to Matt for this answer: https://stackoverflow.com/a/19941501

PayPal IPN Simulator Bad Request


CiviCRM 5.12.0 - Case API returning an Analyzer object containing XML and JSON. Only want JSON

Question: I had a working script set up to create cases in CiviCRM using REST.https://domain.com/administrator/components/com_civicrm/civicrm/extern/rest.php?entity=Case&action=create&json=1&version=3&key=xxxxxxxx&api_key=yyyyyyy(obviously with the correct payload etc). This worked fine. It returned the specified return:id etc in a nice small JSON. Now, the same script is failing because it can't parse the returned JSON. It seems that the API is now returning a Civi\CCase\Analyzer Object which contains the full case data as XML and as JSON. Is this change intentional? Is it documented anywhere? I'm wondering how to extract the JSON from the returned Analyzer object. Thanks.
Comment: I'm not seeing any xml when I run it (on a drupal site). Is there something interesting about the way you run it? I tested with: curl -X POST '`http://site/civicrm/extern/rest.php?json=1`' -H 'Content-Type: application/x-www-form-urlencoded; charset=UTF-8' --data 'entity=Case&action=create&api_key=12345&key=12345&contact_id=user_contact_id&case_type_id=1&subject=fromExternRest'
Comment: Thanks. I tried the same thing as you, using curl, but the response I'm getting is a full dump of the newly-created Case in XML, including all associated activities and relationships, and then the JSON at the end of the output. I'm using Joomla, but I can't imagine that would make a difference? The script has been working fine for months, and I haven't done anything to it.
Comment: The output starts like this, and goes on for a couple of thousand lines:
Civi\CCase\Analyzer Object
(
    [caseId:Civi\CCase\Analyzer:private] => 775
    [case:Civi\CCase\Analyzer:private] => Array
        (
            [id] => 775
            [case_type_id] => 9
            [subject] => fromExternRest
            [start_date] => 2019-04-12
            [status_id] => 1
            [is_deleted] => 0
            [created_date] => 2019-04-12 21:16:32
            [modified_date] => 2019-04-12 21:16:32
            [contact_id] => Array
                (
                    [1] => 66
Comment: Can you do a grep for var_dump or print_r? I'm thinking some debugging code was added in and is producing that output.
Comment: OK, I couldn't see anything which looks suspect. But maybe you can spot something. The grep output is here - https://pastebin.com/nRCKcCky and here:
https://pastebin.com/Hu82Atgi
Comment: Hmm. Is debugging is turned on in the admin screen? Maybe it's causing some extra output?
Comment: No. Debugging is off. Backtrace was on, but turning it off has made no difference.
Answer: Not a direct answer, but following on from the comments here are some more things you can try.

If you haven't already, check the civicrm log. Maybe there is something helpful there. For example maybe there is a recoverable error happening but it dumps some output to stdout instead of the log, which during a REST call will be part of the response output.
It's possible you have some code or an extension that implements the civicrm_caseChange hook and then does some debug output. When looking or grepping be sure to look in any custom php and extension folders defined at admin -> system settings -> directories.
Use diff -r or kdiff or something to compare your civicrm tree to a fresh unzipped 5.12 download to see if there's any differences.
It's definitely print_r output, but it might be coming indirectly from something that calls 'CRM_Core_Error::debug(' or 'CRM_Core_Error::debug_var(', so can try grepping for that. Note I've included the opening bracket in the search string since I'm thinking that will give the least false matches.
Try disabling some extensions one by one.
Run a php step-debugger to see exactly what step it gets output and where it's coming from. This will be time consuming, but you will almost certainly find it. If you can reproduce the problem on a local development copy of the site it will be slightly easier to set this up using that copy.
Comment: Genius, thank you. The problem was caused by an extension which included a function implementing the caseChange hook (the function is very short, and just sends an email whenever a case is changed). I've pasted it here: https://pastebin.com/qH94m7EX. I'm not sure why it's outputting the contents of $analyzer, or how this gets into the response of the api create function. Anyway, we don't need it, so I have just commented it out, and the api response is now just the expected json. Thanks very much for your help.
Comment: Great. By the way in that function if you just change `print_r($analyzer);` to `print_r($analyzer, true);` it will work as it seems like it was intended. Without the "true" it sends the output to stdout instead of returning a string, which is why you see it in the REST output.
Comment: Another casualty of when debugging actually *causes* bugs.


Why do yeast ferment Equal sweetener

Question: I had my students conduct a fermentation experiment manipulating sugar amounts (number of sugar packets in solution) and measuring CO₂ production via capture in a balloon and measuring circumference (very common HS lab experiment). I also had them conduct a trial with two packets of Equal sweetener. To everyone's surprise two packets of the "zero calorie" sweetener produced as much CO₂ as four packets of sugar. Can anyone shed light on why this would have occurred? Equal contains maltodextrin and dextrose in addition to the aspartame. I'm assuming that yeast are able to metabolize one or more of these substances, but I haven't been able to find a more detailed explanation.
Answer: Your sugar substrate was sucrose. Yeast cells metabolise this by secreting an enzyme, invertase, which splits the disaccharide into glucose and fructose both of which can be fermented by yeast to produce CO2.
According to this site

Equal Original (blue packaging)  is a zero calorie sweetener that contains aspartame and acesulfame potassium as its sweetening ingredients along with a bulking agent.
Equal Original PACKETS:
dextrose with maltodextrin, aspartame, acesulfame potassium

This agrees with what you say - that the sweetener that you used contained dextrose - and leaves me very confused. Dextrose is another name for glucose so how can this contain zero calories?
The answer lies in the legal definition of zero calories  = less than 5 calories per serving (presumably per package in this case.) So let's assume that by adding two packs you were adding 8 calories equivalent of glucose.
Calorie content of carbohydrate = 4 calories per gram
Two packs could contain 8 calories = 2 g glucose.
The molecular weight of glucose = 180
therefore 2 g = 2/180 moles
if completely fermented to CO2 each mole -> 6 moles CO2
12/180 moles CO2 = 0.75 litres of CO2.
I conclude that there is enough glucose in two packets of Equal to generate a reasonable amount of CO2.
Yeast cannot ferment maltodextrins. It is possible that aspartame (aspartyl-phenylalanine-methyl ester) could be metabolised, but I think the dextrose/glucose solution is the best explanation.
EDIT:
I meant to say, just to illustrate that this is a significant amount of glucose, standard rich yeast medium is 2 g glucose /100 ml (2 % w/v).
EDIT #2 My back-of-an-envelope calculation has a fundamental error in it, but luckily I am the first to spot it. If glucose is being used fermentatively, then only one third of the carbon will end up in CO2, with the remainder going to ethanol. This means 0.25 litres instead of 0.75 litres. Yeast is so oriented towards fermentation that even in the presence of oxygen the fermentative pathway will dominate.
Comment: I agree with all of this, except there is one problem with the data. (Keep in mind this was High School Bio) A packet of equal is far less mass than a packet of sucrose(since aspartame has such a high sweetness profile), and as such a packet contains a very small amount of dextrose compared to the amount of glucose/fructose in the sucrose packets. That said, there was nearly as much CO2 generated by two packets of Equal as four packets of sucrose. Granted, there is an upper limit to the yeast growth curve and metabolism, but there were higher rates as we increased from 2 to 4 packets sucrose.
Comment: Without knowing the actual contents of one pack of Equal we are at an impasse. However it is noteworthy that the formulation quoted in my answer says "Dextrose with ...". I'm not familiar with US labelling law, but in the EU the first-listed ingredient is present at the highest level. And of course glucose is probably cheaper than aspartame so it would make commercial sense to use the highest amount of glucose possible while remaining "zero calories".
Answer: I don't have a definitive answer to this, but a little over a decade ago I was in an undergraduate lab that had a similar thing happen - a small amount of metabolism of a "control" group of bacteria fed artificial, sugar/calorie free sweeteners instead of sugar.
Our running theories at the time were:

Contamination. Always a problem in laboratory experiments, and especially undergraduate lab experiments.
Trace contaminants. "Zero calorie" isn't actually 0, it's just small, and hardy microorganisms may be able to do just fine with small amounts of nutrients. If there's another factor limiting their growth, that may result in the identical CO₂ results.
Some intermediate compound or the like that is useful for metabolism. As you said, possibly the ability to use maltodextrin or dextrose.
Answer: Equal is marketed as a "zero calorie" sweetener, with respect to human digestion. The sweetening agents are aspartame (Asp-Phe; a dipeptide) and acesulfame K. The maltodextrin and dextrose are probably bulking agents to give the product a free-flowing, poweder consistence.
The "fermentables" in question are:

Dextrose. This is another name of glucose, and is the most easily metabolized sugar in the Equal packet.
Maltodextrin is an oligomer of D-glucose linked by $\alpha$(1,4) linkages. If this were the disaccharide of glucose-glucose, or maltose, then yeast could readily ferment this. However, yeast cannot hydrolyze maltodextrin and therefore cannot metabolize it.
Aspartame is a dipeptide which can easily be fermented.

Therefore, yeast will happily metabolize dextrose and aspartame, but not the other two agents.
Comment: I don't think it is correct that dextrose is linear. Since the two cyclic pyranose forms (alpha and beta) are in equilibrium with the linear form in solution it's not clear how you would be able to isolate pure acyclic glucose (less than 1 % of what is present in solution), and even if you could, as soon as it went into solution it would equilibrate to the pyranose forms again.
Comment: Alan, quite right. I made a mistake. The open chain form is in equilibrium with alpha and beta cyclic pyranose and furanose forms. I have corrected myself.

Why do yeast ferment Equal sweetener


What's the proper build environment for an oem.tgz under esxi 4.1

Question: I've got an unsupported SATA card that I want to use under esxi.
Not really a problem -- I'm not planning on asking for support for this system; it's mostly a basement computer that I'll use for fiddling around with esxi or olive or opensolaris or whatever other fad-of-the-month comes along.
A little googling turns up articles describing building a new oem.tgz file to add drivers for stuff not originally included in the esxi distribution.  One describes adding support for a marvell ethernet card, this link even describes getting my sata card working under esx 4.0.
In fact, there is even a site that has all sorts of community contributed oem.tgz files compiled to include all sorts of drivers.
The problem is that each article seems to describe a different build environment (centos 5.3 or centos 5.4) and targets an older version of ESXi (4.0 vs the current 4.1).
Is it as "simple" as downloading the opensource components of the current version of vmware and compiling the necessary drivers?  Will any up-to-date centos/redhat distribution be suitable?
Answer: You can try the method described in your first link and pray that it works. Frankly, I'm not sure if it's even worth the effort. Wouldn't it be easier to just buy a compatible card. vmware esx/esxi will basically take the compatible linux drivers with some modifications but you have to know what those modifications are and sometimes you might even have to modify the source quite a bit.


USB Hub to power 8 Pis

Question: Would this USB hub work to power 8 Pi 3's? If not... What are clean powering options for a cluster of 8?
Comment: As reference, here is a link to all of the raspberry pi model's [current requirements](https://www.raspberrypi.org/help/faqs/)
Answer: A USB hub will likely not be enough to power 8 Pi's. The spec is for 500mA per port (USB 2) and 900mA (USB 3). I don't know of any hub that could supply 8 Amps (1 amp per port). All of the Pi cluster setups I have seen are using a multi device USB charger. I would suggest doing a google search for Pi cluster and looking at what they are using. One thing to note is since you are planning to use Pi 3s solutions using the Pi Zero, probably don't apply as they have lower power requirements.
Comment: I can't quite grok that last sentence - what doesn't apply to Pi Zero?
Comment: @goobering Because the Pi Zero has lower power requirements than the  Pi 3, power solutions which may work for powering a PI Zero based cluster likely will not work when powering a  Pi 3 based cluster.
Answer: I don't think that the device you linked to will do what you want.  It's power supply is 5V 2A, which is not going to last very long trying to power 8x Raspberry Pi B's or B+s.  According to this answer, you may be fine with Pi Zeros though.
You probably want to get something like this.  There is a class of device like this that will provide full power to all USB ports, and that's what you want to look for.  I have one of these, and I tested with a Pi B+ when I got it, and it will power the Pi B+.  Presumably, it will power any other Pi as well.  The only thing I found that it won't power are some older Windows Mobile phones, but that could be because the batteries are too old to take a charge.
Answer: I went ahead and purchased the hub I originally ask about and it is currently working and powering all 8 nodes. The hub allanonmage mentioned should work as well. Happy clustering!
Comment: Did you try frying an egg on the PSU yet? :P
Comment: Barely even warm to the touch
Comment: Glad to hear it :)
Comment: What are the Pis doing?  Wifi enabled?  I wonder if you lucked out and they're in some kind of low power draw mode because they're not trying very hard.  To be fair, I think the Pi itself draws ~500ma of current, but according to this post, that might just be under load http://raspberrypi.stackexchange.com/questions/26526/current-draw-for-2-0-models

USB Hub to power 8 Pis


How to reduce NET and CPU usage in Private EOS

Question: I am trying to setup a private eos for my app, I want to know if there is possible to change the usage of CPU, NET etc in private setup without staking tokens. If YES, then please guide me with the procedure.
Comment: I don't understand what you are asking for.
Comment: I want to setup a local setup of eos, I want that if a user has not staked tokens he can still be able to make transactions on the local network
Answer: Easy:
Use eosio.bios instead of eosio.system contract
Advanced:
newaccount in eosio.system initializes account's resources with 0.
   void native::newaccount( const name&       creator,
                            const name&       newact,
                            ignore<authority> owner,
                            ignore<authority> active ) {
      /* ... */

      user_resources_table  userres( get_self(), newact.value );

      userres.emplace( newact, [&]( auto& res ) {
        res.owner = newact;
        res.net_weight = asset( 0, system_contract::get_core_symbol() );
        res.cpu_weight = asset( 0, system_contract::get_core_symbol() );
      });

      // three zero params mean ram, net and cpu in order
      // you can change these to proper values, or set -1 to make them unlimited
      set_resource_limits( newact, 0, 0, 0 );
   }

Comment: Yes, eosio.bios contract works well for me. You'll be able to create accounts, set the producer schedule and get ordered transaction history as per normal.
Answer: You can't just reduce the resources usage if you want to get an alternative and don't have EOS tokens for stake see the REX(Resources Exchange System) in eosio documentation.
Also must watch this video for simple explanation of REX video.
For explanation of different REX functionalities see this blog article


Drupal migration api: set custom plugin as source in «process» section

Question: I migrated nodes including metatags from D7 to D8. As soon as metatags are not field in D7 I do not have it as common source in d7_node plugin. Of course, I can extend this plugin with my own and make join with metatag database table. But this variant seems for me not ideal. As I understand I can't execute any db queries inside process plugins, so I need to feed my custom source plugin result to a metatag field in a process section of my migration config. How can I do it and is it possible?
Answer: Yes, it is possible to migrate fields but I don't know Metatags.There is an existing issue in Metatags for creating a migration, it may be of help. https://www.drupal.org/project/metatag/issues/2563649


How to make microwaved condensed milk caramel sauce properly?

Question: When I tried making, but it always necomes pieces, and if I continue to turn it into a caramel brown colour, very dry, and turns into candy. What is the a recipe for making a caramel sauce in a microwave? I want it to be like canned dulce de leche. Unfortunately, I learned what cans might be leaching unsafe plastics (like BPA) into foods if boiled, so I won't do that.
Comment: Is there a reason you want to stick with using the microwave?  If its boiling the cans that concerns you, but not the boiling itself, you could always transfer your sweetened condensed milk into another container, like a mason jar, and boil that.  Mason jars are meant for canning, so should be completely safe for such an application.
Comment: What recipe or method are you following -- just microwaving the sweetened condensed milk? For how long?
Answer:
Put Sweetened Condensed Milk into a microwave safe bowl and whisk it thoroughly until its smooth and the thicker stickiness from the bottom of the can that has settled is evenly distributed again.
Place in microwave at 50% power for 2 minutes then take it out and stir thoroughly. Do NOT use full power!  If you do it will burn, and it will look similar to what you mentioned was happening to yours - it turns into a brown dry solid.
Put back in microwave (50% power again) for 1 minute increments, stirring in between each additional minute until it has reached the level of darkness you are looking for.

Hope this is what you are asking for.


What is +1 in binary search time complexity

Question: Why is binary search time complexity for worst case log (n) + 1 instead of just being log(n)? the way I understand it, the number of times we divide the list till we find our desired element is log (n) times in the worst case scenario. Where does this extra 1 come from? (it's log (n) + 1 according to the power point of my class)
Answer: The exact number depends on your assumptions, so either is defensible.  If you assume that the number you're searching for is definitely in the list, and it's just a matter of finding it, then the number of comparisons needed can be as large as $\lceil \lg n \rceil$, and won't be any larger than that.  (Here $\lceil \cdot \rceil$ represents rounding up to the nearest integer.)  Since $\lceil \lg n \rceil \le 1 + \lg n$, it is not unreasonable to describe the worst-case number of comparisons needed as $1 + \lg n$.  Again, as a reminder, this assumes that the number you're searching for is definitely present.
That said, in theoretical analysis, we usually ignore constant factors.  So, we summarize the running time as $O(\lg n)$.  For these purposes, there is no difference between $\lg n$ or $\lg n+1$; they are both $O(\lg n)$.


Can I upgrade old case USB 1.1 sockets to USB 2?

Question: My new mobo has USB 2 but the old case has USB 1.1 sockets. At least, that's what the software tells me. Each time I plug in my stick, I'm reminded that the device will work quicker if I use USB 2.
I know some recommend a new USB PCI card but I want to connect through the casing front sockets (to the mobo).
If there's a small replacement USB PCB with connectors available, I can't find it. I'm toying with the thought that it's the actual socket which announces what version will run. The Wikipedia entry for USB is too difficult for me but it does state some impedance values. I remember Impedance from school and I remember also that was my last memory before I gave up learning.
Maplin sells both versions (strangely, for the same price) and they do look different. So I'm thinking of changing the socket on the board. Any ideas?
Comment: From your description, is sounds like the (memory?) stick may be a 1.1 device.
Answer: Here's that Wikipedia link; the interesting bit is in the Signaling section.  As others have noted, there is no difference in the connectors.
Now, the problem you're having could be due to a few things; possible corrosion on the old connectors seems most likely, though cheap wiring between the case's connectors and the motherboard could be picking up interference and not allowing the USB2 handshake to succeed.  If you're up for the case modding, replacing the case's front sockets and interior cabling should fix both possibilities.
The only other potential source of the problem (that I can think of) is that the front sockets may be part of a small PCB which includes a USB 1.1 controller.  If that's the case you should be able to remove it without much trouble, and install USB sockets that wire directly to the motherboard.
Answer: ALL USB 1.1 connectors and full-speed cables are capable of connecting to, and running at, USB 2.0 specifications.
In other words, you are only limited by the USB controller physically mounted either on your motherboard, or in a peripheral slot.
So, yes, those ports on the front of your case WILL convert to USB 2.0 ports as long as they are connected to a USB 2.0 controller.
To make the best possible match, ensure that you have proper cables for your task:
full-speed cables = 12Mb/s
low-speed cable = 1.5Mb/s
I hope this helped.
Comment: Remember that High Speed ~= 480Mb/s.
Answer: What sort of case do you have?  Most cases that I've seen that have front USB ports connect them to the motherboard via a cable.  Do you have some sort of case where the front ports are hardwired to your motherboard?
USB functionality is provided by a controller chip of some sort.  There is no physical difference between USB 1.1 and 2.0 sockets that I've ever encountered.


How are regression, the t-test, and the ANOVA all versions of the general linear model?

Question: How are they all versions of the same basic statistical method?
Comment: related: [Why is ANOVA taught / used as if it is a different research methodology compared to linear regression?](https://stats.stackexchange.com/questions/555/why-is-anova-taught-used-as-if-it-is-a-different-research-methodology-compared)
Comment: related: [R: Anova and Linear Regression](https://stats.stackexchange.com/questions/76250/r-anova-and-linear-regression)
Comment: related: [Why is ANOVA equivalent to linear regression?](https://stats.stackexchange.com/questions/175246/why-is-anova-equivalent-to-linear-regression)
Answer: Consider that they can all be written as a regression equation (perhaps with slightly differing interpretations than their traditional forms).
Regression:
$$
Y=\beta_0 + \beta_1X_{\text{(continuous)}} + \varepsilon  \\
\text{where }\varepsilon\sim\mathcal N(0, \sigma^2)
$$
t-test:
$$
Y=\beta_0 + \beta_1X_{\text{(dummy code)}} + \varepsilon  \\
\text{where }\varepsilon\sim\mathcal N(0, \sigma^2)
$$
ANOVA:
$$
Y=\beta_0 + \beta_1X_{\text{(dummy code)}} + \varepsilon  \\
\text{where }\varepsilon\sim\mathcal N(0, \sigma^2)
$$
The prototypical regression is conceptualized with $X$ as a continuous variable.  However, the only assumption that is actually made about $X$ is that it is a vector of known constants.  It could be a continuous variable, but it could also be a dummy code (i.e., a vector of $0$'s & $1$'s that indicates whether an observation is a member of an indicated group--e.g., a treatment group).  Thus, in the second equation, $X$ could be such a dummy code, and the p-value would be the same as that from a t-test in its more traditional form.
The meaning of the betas would differ here, though.  In this case, $\beta_0$ would be the mean of the control group (for which the entries in the dummy variable would be $0$'s), and $\beta_1$ would be the difference between the mean of the treatment group and the mean of the control group.
Now, remember that it is perfectly reasonable to have / run an ANOVA with only two groups (although a t-test would be more common), and you have all three connected.  If you prefer seeing how it would work if you had an ANOVA with 3 groups; it would be:
$$
Y=\beta_0 + \beta_1X_{\text{(dummy code 1)}} + \beta_2X_{\text{(dummy code 2)}} + \varepsilon  \\
\text{where }\varepsilon\sim\mathcal N(0, \sigma^2)
$$
Note that when you have $g$ groups, you have $g-1$ dummy codes to represent them.  The reference group (typically the control group) is indicated by having $0$'s for all dummy codes (in this case, both dummy code 1 & dummy code 2).  In this case, you would not want to interpret the p-values of the t-tests for these betas that come with standard statistical output--they only indicate whether the indicated group differs from the control group when assessed in isolation.  That is, these tests are not independent.  Instead, you would want to assess whether the group means vary by constructing an ANOVA table and conducting an F-test.  For what it's worth, the betas are interpreted just as with the t-test version described above: $\beta_0$ is the mean of the control / reference group, $\beta_1$ indicates the difference between the means of group 1 and the reference group, and $\beta_2$ indicates the difference between group 2 and the reference group.

In light of @whuber's comments below, these can also be represented via matrix equations:
$$
\bf Y=\bf X\boldsymbol\beta + \boldsymbol\varepsilon
$$
Represented this way, $\bf Y$ & $\boldsymbol\varepsilon$ are vectors of length $N$, and $\boldsymbol\beta$ is a vector of length $p+1$. $\bf X$ is now a matrix with $N$ rows and $(p+1)$ columns.  In a prototypical regression you have $p$ continuous $X$ variables and the intercept.  Thus, your $\bf X$ matrix is composed of a series of column vectors side by side, one for each $X$ variable, with a column of $1$'s on the far left for the intercept.
If you are representing an ANOVA with $g$ groups in this way, remember that you would have $g-1$ dummy variables indicating the groups, with the reference group indicated by an observation having $0$'s in each dummy variable.  As above, you would still have an intercept.  Thus, $p=g-1$.
Comment: The ANOVA equation would make sense as an ANOVA (and not a t-test) only if $\beta_1$ were interpreted as a *vector* and multiplied on the right.
Comment: Could you please explain a bit more on how you arrive from popular definition of t-test to the equation you have shown.Basically I can't figure out what is Y here (it could be naivity or less IQ for stats). However how to arrive from t = (y-x-u0)/s to this equation.
Comment: These aren't matrix equations; I rarely use those here, as many people don't read them. The 1st ANOVA represents an identical situation as the preceding t-test. I'm just pointing out that if you can run a 2-sample independent t-test, you can run the same data as an ANOVA (which many people should recognize / remember from their stats 101 class). I add another ANOVA version w/ 3 groups lower down to clarify that a 2-group situation isn't the only ANOVA case that can be understood as a regression; but the reg equation now looks different--I was trying to maintain a more explicit parallel above.
Comment: My point is that unless you *do* make it a matrix equation, your characterization of ANOVA is too limited to be useful: it is *identical* to your characterization of the t-test and so is more confusing than it is helpful. When you start introducing more groups, you suddenly change the equation, which may also be less than clear. Whether you want to use matrix notation is of course up to you, but in the interest of communicating well you should strive for consistency.
Comment: It doesn't, although this may be unfamiliar to you. $Y$ is continuous (& assumed conditionally normal) in all cases listed. There are no distributional assumptions about $X$, it can be continuous, dichotomous, or a multi-level categorical variable.
Comment: @hxd1011, in response to whuber's comments, towards the end of this answer I included an example of an ANOVA w/ 3 groups, and then the matrix  formulation.
Comment: @hxd1011, I'm going to stay with the answer I have here.
Comment: A key point to note here is that the t-test above is the version where it assumes the variances are equal, which is the pooled variance t-test. Therefore the linear regression assumes the variances are the same across groups.
Comment: @user321627, that's true: standard OLS regression [assumes homoscedasticity](https://stats.stackexchange.com/a/52107/7290). That can be relaxed various ways, though.
Answer: They can all be written as particular cases of the general linear model.
The t-test is a two-sample case of ANOVA.  If you square the t-test statistic you get the corresponding $F$ in the ANOVA.
An ANOVA model is basically just a regression model where the factor levels are represented by dummy (or indicator) variables.
So if the model for a t-test is a subset of the ANOVA model and ANOVA is a subset of the multiple regression model, regression itself (and other things besides regression) is a subset of the general linear model, which extends regression to a more general specification of the error term than the usual regression case (which is 'independent' and 'equal-variance'), and to multivariate $Y$.

Here's an example showing the equivalence of the ordinary (equal-variance) two sample-$t$ analysis and a hypothesis test in a regression model, done in R (the actual data looks to be paired, so this isn't really a suitable analysis):
<code>> t.test(extra ~ group, var.equal=TRUE, data = sleep)

    Two Sample t-test

data:  extra by group
t = -1.8608, df = 18, p-value = 0.07919
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
 -3.363874  0.203874
sample estimates:
mean in group 1 mean in group 2
           0.75            2.33
</code>
Note the p-value of 0.079 above. Here's the one way anova:
<code>> summary(aov(extra~group,sleep))
            Df Sum Sq Mean Sq F value Pr(>F)
group        1  12.48  12.482   3.463 0.0792
Residuals   18  64.89   3.605
</code>
Now for the regression:
<code>> summary(lm(extra ~ group, data = sleep))
</code>
(some output removed)
<code>Coefficients:
            Estimate Std. Error t value Pr(>|t|)
(Intercept)   0.7500     0.6004   1.249   0.2276
group2        1.5800     0.8491   1.861   0.0792 .
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 1.899 on 18 degrees of freedom
Multiple R-squared:  0.1613,    Adjusted R-squared:  0.1147
F-statistic: 3.463 on 1 and 18 DF,  p-value: 0.07919
</code>
Compare the p-value in the 'group2' row, and also the p-value for the F-test in the last row. For a two-tailed test, these are the same and both match the t-test result.
Further, the coefficient for 'group2' represents the difference in means for the two groups.
Finally note that $F=t^2$ for the statistics; this is also a fact about the reference distributions (that $t^2$ is $F$).
Comment: Having same p values in all 3 scenarios is magical and impressive, however if you could explain a bit more on how these p-values gets calculated, it would definitely make this answer more *interesting*. I don't know if showing p-value calculations will make it more **useful** as well,  so that is something you could decide.
Comment: @Gaurav The p-values are the same because you're testing the same hypothesis on the same model, just represented slightly differently. If you're interested in how some specific p-value is calculated, it would be a new question (it would not be an answer to the question here). You're free to ask such a question though try a search first since it may already have been answered.
Comment: Thanks @Glen_b, sorry for asking an obvious question and that too in not the best way. And you still answered my question - "same hypothesis on the same model (and/or data)". I did not give enough thoughts on how they are testing the same hypothesis. Thanks
Answer: This answer that I posted earlier is somewhat relevant, but this question is somewhat different.
You might want to think about the differences and similarities between the following linear models:
$$
\begin{bmatrix} Y_1 \\ \vdots \\ Y_n \end{bmatrix} = \begin{bmatrix} 1 & x_1 \\ 1 & x_2 \\ 1 & x_3 \\ \vdots & \vdots \\ 1 & x_n \end{bmatrix} \begin{bmatrix} \alpha_0 \\ \alpha_1 \end{bmatrix} +  \begin{bmatrix} \varepsilon_1 \\ \vdots \\ \vdots \\ \varepsilon_n \end{bmatrix}
$$
$$
\begin{bmatrix} Y_1 \\ \vdots \\ Y_n \end{bmatrix} = \begin{bmatrix} 1 & 0 & 0 & \cdots & 0 \\ \vdots & \vdots & \vdots & & \vdots  \\ 1 & 0 & 0 & \cdots & 0 \\ \hline 0 & 1 & 0 & \cdots & 0 \\ \vdots & \vdots & \vdots & & \vdots \\ 0 & 1 & 0 & \cdots & 0 \\  \hline 0 & 0 & 1 & \cdots & 0 \\  \vdots & & & & \vdots \\ \vdots & & & & \vdots \end{bmatrix} \begin{bmatrix} \alpha_0 \\ \vdots \\ \alpha_k \end{bmatrix} +  \begin{bmatrix} \varepsilon_1 \\ \vdots \\ \vdots \\ \varepsilon_n \end{bmatrix}
$$
Comment: Some description and comment to the questions would useful for the readers since now they have to guess where did they came from and how do they relate to the question...
Answer: Anova is similar to a t-test for equality of means under the assumption of unknown but equal variances among treatments. This is because in ANOVA MSE is identical to pooled-variance used in t-test. There are other versions of t-test such as one for un-equal variances and pair-wise t-test. From this view, t-test can be more flexible.


Is there a standard rating system for scientific journal publications?

Question: I have heard that some journals are rated more highly than others.  Is this true? And if so, what are the criteria for judging the value of one peer reviewed journal over another?  How do I find out its rating?  Will my publication be of less "worth" if it is accepted in a less reputable journal than, say, the SIAM Review?
Comment: This question might be considered off-topic, subjective, or too broad.  But I think it's worth discussing here and will write an answer.
Comment: @DavidKetcheson: That was my feeling as well.
Answer: In an ideal world, you would only consider one thing when choosing where to submit a manuscript:

which journal's readership includes the broadest audience that would
  be interested in this work?

In practice, you also consider other factors, perhaps most significantly

How much will publishing in this journal help my career?

Anyone who can understand your work well will judge it by its actual significance, but those who are too far removed may use the quality of the journal as a proxy for the quality of your paper.
How is journal quality determined?  Experienced professionals have their own opinions based on experiences with each journal and the articles they read.  In some fields, like mathematics, this expert opinion can only be synthesized by talking to a lot of experts.  In other fields, like computer science, this has been explicitly codified into a tiered ranking system.
The most widely available metric for journal quality is the so-called impact factor.  The danger of having a single, widely used metric for anything is that it may be manipulated or misapplied, or may simply not be useful for some of the things it is applied to.  For instance, since it only measures citations over two years, it doesn't make much sense for mathematics papers, which typically get most of their citations after two years -- often much later.  It also seems to be poorly correlated with expert opinion.  There are alternatives, for instance Eigenfactor.  And many people are now proposing the use of social web metrics to rank journals.
I do not use the impact factor or other such metrics in my own decisions, as I feel that my direct experience gives me a more accurate measure of a journal's significance.  An interesting exercise is to go through your personal library of references (e.g., in a bibtex file) and see the number of articles it contains from different journals.  That will probably give you the best indication of where you should publish.
By the way, there is a proposal to create an expert-based ranking of math journals; see this report and this official IMU blog.
You should also be aware that there has recently been an explosion of new low-quality journals based on an author-pay model.  Their publishers frequently spam large communities of scientists (often including many who are unqualified) in an attempt to get reasonably respectable names on their editorial boards and solicit paper submissions.  As far as I can tell, they are profit-oriented vanity press.
Comment: @Paul good question; it's usually fairly obvious.  The signs are that they spam lots of people, enlist unqualified editors, and require that you pay in order to publish.  They also usually have poorly written messages and websites (in terms of basic things like grammar and spelling).
Comment: I agree with @DavidKetcheson's comments, but will add a few of my own.

Having sat on the math Discovery Grant panel for [NSERC](http://www.nserc-crsng.gc.ca/professors-professeurs/grants-subs/dgigp-psigp_eng.asp) there are many pitfalls in using journal impact factors to gauge quality of individual papers.  Even the best journals contain papers with a broad range of quality, and mediocre (or erroneous) results do slip through even the best of peer-review processes.  That said, I would still find the list proposed by the IMU/ICIAM or from the AustMS (mentioned by @Dirk) to be useful.
Comment: How do you distinguish these 'vanity press' publishers from the quality, peer-reviewed publishers?
Comment: In considering how broad the audience is, you may want to consider if the journal is open access and if the journal has data and code archiving policies. Research has shown [1](http://www.ncbi.nlm.nih.gov/pubmed/17375194) [2](http://dx.plos.org/10.1371/journal.pone.0026828) [3](Making data maximally available.) that open access journals receive broader readership and higher impact.  Alternatively if you don't want to release data and code, journals with archiving mandates may be a poor choice.
Comment: @cboettig In math, I suspect that actual readership may be negatively correlated with open access, due to the unfortunate deluge of low-quality "open-access" publishers.  Of course, the arXiv gets to a very broad audience!  It's my preferred open access "publisher".
Answer: It really depends on how much you believe in journal ratings. The most popular metric I am aware of is the impact factor. This Wikipedia article describes the impact factor, how it is calculated, and how it is susceptible to manipulation, as well as alternative journal rating metrics. The most important thing worth noting is that impact factors for journals in different fields aren't necessarily comparable, even though the impact factor rating system tries to collapse the "quality" of each journal onto a single metric. (For an interesting discussion on why such an idea can lead to misleading or easily manipulable results, see Malcolm Gladwell's New Yorker essay, The Order of Things, which discusses college rankings and car rankings.)
The impact factor is the average number of citations received per paper published in that journal during the two preceding years, so the criteria for judging the value of one peer reviewed journal over another is how many times its recent articles get cited on an average, per article basis. This metric does mean that journals like Science and Nature are ranked highly, as one would expect, but it also means that International Journal of Nonlinear Sciences and Simulation (3.100) gets ranked higher than SIAM Journal of Scientific Computing (3.016), even though the latter journal is a lot more recognizable.
As for your publication being of less "worth," it depends on the person. I've been told by my more senior colleagues that having articles in more prestigious journals is helpful for things like tenure and hiring decisions; not having experience with such matters firsthand, I defer to the comments of people who are have more background with those sorts of situations. It depends on the community of people you are trying to reach or impress. If you publish something in a math journal, don't expect that people outside mathematics will necessarily read it. (The same advice applies to other subjects.) Also, you may decide to publish in a less prestigious journal because you want to get a result out quickly rather than wait a long time for it to be reviewed by more prestigious journal. I've been told that the SIAM journals can take a year or more to review a paper and publish it, which is backed up by looking at the time between the submitted date and the published date on the paper. Submission to a particular journal is also dependent on aims and scope, politics (who is on the editorial board, who is likely to review your paper), what community you want to reach out to (sort of goes with the advice about subject area above). I still consult other people on these matters.
When I look at articles, the "prestige" of a journal, to me, is really my internal feeling that reflects the valued opinions of other people I know in science (my advisers, colleagues, etc.). I'm more inclined to trust an article in a journal that is more prestigious because I feel it is more likely to be reliable, but there are certainly bad articles in prestigious journals, so prestige is not a replacement for doing your own due diligence. For example, there are some pretty serious typos in an otherwise good journal article I've cited from SIAM Review.
Anyway, that's my rambling opinion, and as a (nearly) freshly-minted PhD, I'm sure that others with more experience will have much more perspective and insight to add.
Comment: Good summary. Wait times depend as much on subject matter as "prestige". Math heavy papers take much longer to get reviewed than a software oriented paper, for example, at least in my experience. Thanks for the New Yorker link. It is a good read.
Answer: What factors determine where I will publish a paper?

Will the people I want to read this paper see it? If I'm following up on the work of another group (perhaps to show a different viewpoint, sometimes to show algorithmic improvements or to fix problems with a previous paper), I will want to submit the paper to the same journal, even if there's an impact factor issue.

As a young computational scientist still in the career development phase of my career, I would submit that there is an additional, and perhaps even more critical aspect to this question. . . .

Will people who may be in a position to evaluate me see this paper? I've often spoken with peers in the computational science field about the need to have a "home turf": computational science is a highly interdisciplinary field. Unfortunately, we are not really able to be considered as computational scientists when it comes time to be considered for a permanent position. In the absence of working in a computational sciences department, We will have to apply for tenure in an existing department, which usually means that our "peers" will be other engineers, scientists, and mathematicians—many of whom do not really have a strong background in computational science. This means that even if you want to go in the cross-fertilizing direction, you still need to focus some of your publications in the go-to journals for your discipline. This is a challenge that many of our peers will not necessarily have to face, and it's an additional complication in our lives. But it's something we have to be aware of before we start working!
How much competition do I have right now? The more crowded a field, the more important it is to get the results in early. While it's great to try to go to Nature or Science with every paper out of your group (presuming you're not in pure math, or something similar), being first out of the gate in a "hot" field matters much more than publishing in the "best" journal in a field.
How important is this paper? A paper that represents a body of work that provides a lot of new data, but not really much in the way of ground-breaking insight, probably doesn't merit going to a top-level journal. It's probably better to look for a reputable journal. However, if you've really found something big, shoot high, so long as you're not worried about the time crunch that affects the big journals. (It can take longer, for instance, to publish in Physical Review Letters than in one of the other Physical Review series, which are of comparable quantity.)

After all of these are taken into account, then I'll start worrying about issues like impact factor, but then only as a loose quality control measure. Differences of 10-20% are essentially meaningless, but a 1.0 versus a 2.0, or a 2.0 versus a 3.0, does represent a measurable level of difference between journals.
Answer: Rating is necessarily a subjective activity. If you care about how others will rate your paper, then you need to figure out what their criteria are. As a rule of thumb, the less competence they have in your field of work, the more they will rely on journal rating rather than rating your work, and the more they will rely on bibliometry (impact factors, h factors, ...) rather than personal experience.
Answer: This is a conversation you should be having with the people above you that are going to evaluate you. If you're a PhD student, then you should be talking to your advisor and other professors about how their department and other departments at other institutions evaluate the work of tenure-track faculty when making their tenure decisions. If you're tenure-track faculty now, you should have already had this conversation with your department chair and other members of the department's budget council or similar bodies about how they evaluate the work of tenure candidates. If you're not a professor of some fashion, or if you're an academic in a place without tenure, you should ask the same questions of your supervisor about promotion and retention at your institution.
My experience has been that most researchers don't really read or try to keep up with publications in journals relevant to their areas directly as they come out. Not many people have personal subscriptions to IJNMF, say, and read each month's issue cover to cover. There are just too many venues to keep up with. More often, I find, people are searching for related work, using email or google alerts to seek out related items, and following the work of colleagues and competitors directly. So, the important thing is not trying to get your work seen via journals, but to publish in the best possible venue as determined by those who will be judging your career.
The way to get your work seen is to aggressively market it through conferences, seminars, free software, your website, etc. This probably won't impact your promotions committee's decision (or the like), but if people are seeing and using your work through other venues, and you give them preprints and links to where it is published in the journals, then that will increase your citation counts, which is something important to those above you.
Comment: I for one do read journal tables of contents.  I use an RSS feed aggregator and it only takes a few minutes per week to keep up with about a dozen journals.  I also typically get the articles well ahead of their publication date this way. You can see which ones I read here: http://scienceinthesands.blogspot.com/2011/10/you-are-what-you-read-journals-i-follow.html
Comment: I figured that there were people that kept up more than I do. I'm mostly out of the academic publishing scene (not being on that track). It's certainly easier to keep up now than when everything was paper only. Just out of curiosity, how many articles out of that collection do you end up reading in a month?
Comment: Probably only 1-2 in any depth.  But I get a lot of value out of being aware of work by reading some abstracts.  I'll probably read on the order of 25 abstracts in a month.  The rest are discarded after scanning the title.
Answer: My short answer is: Unfortunately, there is (almost).
There is the rating by the Aust MS for mathematical journals and I think there are other ratings as well. However, in my opinion this is not helpful. I quote from my own blog: "My opinion is that rating is possible but both useless and dangerous. It is possible, since you can ask experienced mathematicians and you will get a reliable answer. It is useless, since you either know which journals are good or you can ask a colleague (which is basically the same reason as the previous one). It is dangerous, since it offers the possibility to form decisions on tenure or grants on these numbers and shifts the focus from what you publish to where you publish."
Comment: Sadly, you _do_ need to worry about both what _and_ where to publish—at least if you're at the stage of your career where you're concerned about needing to find another job.
Comment: Well, the focus should be on *what* is in the paper. Anyway: If you are very good then it will not matter where you publish. At least the mathematical community is quite resistant against measures like the impact factor and relies on opinions by experts (i.e. referees and recommendation letters).
Comment: If you're in a field like math, that's not so much of a problem. However, we don't know specifically which field the OP is in, and so there's a very good chance he might be evaluated by non-computational scientists. Then the whole issue of knowledge versus impressions comes to the fore.
Comment: I guess there are equally as many people on both sides of the issue (whether it's important from a pragmatic perspective)...  In some institutions, it DOES matter where, in others, it matters WHAT.
Answer: There are some ranking systems for citations, which one might argue are decent measures of prestige - important papers get cited more and the like - the most common of these is "impact factor". But these all have their own problems - they're not constant by field, they're susceptible to manipulation by clever researchers, etc. Others that are slightly better are the h-index and g-index, but...meh.
Generally, I've found there is a "feel" in the field for what's good and what's not - and more importantly, what's appropriate and what isn't for your paper. For example, I have one paper that managed to get into a very good journal, but its utterly inappropriate, so it languishes a bit.
Your evaluators or colleagues would probably be the best sources to talk to. Experience is often the best judge of what counts as "good" for a particular paper that would lend itself well to a particular journal. General field (Biology, Medicine, etc.) rankings, or even worse, Academia-wide rankings may not be of any use.


Has any player ever won Super Bowl MVP, Pro Bowl MVP, and MVP in the same season?

Question: Please tell me the name, position, and team of any players that have done this, as well as the year it happened. Also, have any players done it in different seasons?
Answer:
Has any player ever one Super Bowl MVP, Pro Bowl MVP, and MVP in the same season?

No.
Here is a list of regular season MVPs and Super Bowl MVPs in the same season:

Kurt Warner, QB, St. Louis Rams (1999, XXXIV)
Steve Young, QB, San Francisco 49ers (1994, XXIX)
Emmitt Smith, RB, Dallas Cowboys (1993, XXVIII)
Joe Montana, QB, San Francisco 49ers (1989, XXIV)
Terry Bradshaw, QB, Pittsburgh Steelers (1978, XIII)
Bart Starr, QB, Green Bay Packers (1966, I)

None of the aforementioned players have won Pro Bowl MVP.
Note: This will be an unlikely feat moving forward.

The Pro Bowl takes place the week before the Super Bowl. Players in the Super Bowl who were elected to the Pro Bowl typically skip playing in the Pro Bowl.
Popular opinion is that the Pro Bowl may not be played in the near future.
Comment: I forgot that the final four teams in the playoffs do not send players to the Pro Bowl. Thank you!


How to deal with bad past karma that makes my current life miserable?

Question: Before I practice Buddhism,I've made mistakes and hurt other. Sometimes I thought what happen to me now is the effect of what I did.
I try to  keep doing positive things but sometimes I could not stand this hard situation. Could anyone tell me please how to solve this situation in Buddhism way?
Comment: Not sure if it's any consolation, but every time I've said "I can't stand this", the moment passed regardless.
Answer: An understanding of what causes have contributed to the way we are right now is out of the realm of ordinary people; practically speaking, you are more likely to project a false impression of why you are the way you are that is wholly disproportionate in terms of cause and actual effect.
Much of what we are today has already been predetermined from the moment of our conception, including the nature of our body and our brain, our social status and community, and even our life choices and experiences to a certain extent.
That being said, karma performed in this life will certainly have an affect on our minds and influence our choices as well as our mental and physical well-being. Much of this is also out of our control, at least in terms of direct intervention.
What we can do is two things:

We can, as the Buddha taught Angulimala, "bear with" the unpleasant experiences. This has the effect of both neutralizing the mental suffering that comes from unpleasant experiences as well as nullifying any further bad karma we might create in reaction to the experience (thus potentially ending the cycle that caused the experience in the first place).
We can perform wholesome deeds like giving charity or help to others, abstaining from unethical deeds and speech, and practising meditation to calm and clarify our minds. This has the effect of acting as a buffer to our unwholesome deeds, in effect (potentially) counteracting them. As the Buddha taught to Angulimala:

He, who by good deeds covers the evil he has done,
  illuminates this world like the moon freed
  from clouds.
-- Dhp. 173 (Buddharakkhita,trans)
Answer: Regretting about your past is only going to make your Karma worse. Best way to deal with past bad memories is to do Vipassana on them. When a past memory comes to your mind, simply note it as a thought about the past. Don't react to it or take it as something that belongs to you. If that memory truly belongs to you, you should be able to stop it from appearing in the mind. But you can't! Because it appears due to causes. So wishing for such thoughts to go away will only create a need in the mind for it to not be present. But that's only going to make you suffer, which is what you are going through right now. The need for such thoughts to go away doesn't stop them from appearing in the mind again. But if you are able to note it as it is, i.e. just a past thought, and not react to it, you can notice that it fades away immediately.
If you want peace of mind, you must train your mind to note 3 natures of everything that troubles you:

Anicca (impermanence)
Dukka (unsatisfactoriness)
Anatta (non-self)
Answer: According to the "Lonaphala Sutta: The Salt Crystal", the Buddha said:

"Monks, for anyone who says, 'In whatever way a person makes kamma,
  that is how it is experienced,' there is no living of the holy life,
  there is no opportunity for the right ending of stress.
"There is the case where a trifling evil deed done by a certain
  individual takes him to hell. There is the case where the very same
  sort of trifling deed done by another individual is experienced in the
  here & now, and for the most part barely appears for a moment.
"Now, a trifling evil deed done by what sort of individual takes him
  to hell? There is the case where a certain individual is undeveloped
  in [contemplating] the body, undeveloped in virtue, undeveloped in
  mind, undeveloped in discernment: restricted, small-hearted, dwelling
  with suffering. A trifling evil deed done by this sort of individual
  takes him to hell.
"Now, a trifling evil deed done by what sort of individual is
  experienced in the here & now, and for the most part barely appears
  for a moment? There is the case where a certain individual is
  developed in [contemplating] the body, developed in virtue, developed
  in mind, developed in discernment: unrestricted, large-hearted,
  dwelling with the immeasurable. A trifling evil deed done by this sort
  of individual is experienced in the here & now, and for the most part
  barely appears for a moment.
"Suppose that a man were to drop a salt crystal into a small amount of
  water in a cup. What do you think? Would the water in the cup become
  salty because of the salt crystal, and unfit to drink?"
"Yes, lord. Why is that? There being only a small amount of water in
  the cup, it would become salty because of the salt crystal, and unfit
  to drink."
"Now suppose that a man were to drop a salt crystal into the River
  Ganges. What do you think? Would the water in the River Ganges become
  salty because of the salt crystal, and unfit to drink?"
"No, lord. Why is that? There being a great mass of water in the River
  Ganges, it would not become salty because of the salt crystal or unfit
  to drink."

The amount of water corresponds to the degree that the mind is developed. From this sutta we can understand that the fruits of kamma can be minimized through the right development of the mind. A developed mind is like the river Ganges, and an unskilful action, like a salt crystal in the river, will only produce a fruit which will be barely felt.
Answer: You must've already possessed great wholesome kamma to be able to know about Buddhism, to learn and practice it. All the other bad kammas would be trivial compared to what you already had. Learn more about Buddhism and practice diligently and you will transcend them. See the inspiring story of Venerable Angulimala ( http://www.accesstoinsight.org/tipitaka/mn/mn.086.than.html ):

"Then Ven. Angulimala, early in the morning, having put on his robes and carrying his outer robe & bowl, went into Savatthi for alms. Now at that time a clod thrown by one person hit Ven. Angulimala on the body, a stone thrown by another person hit him on the body, and a potsherd thrown by still another person hit him on the body. So Ven. Angulimala — his head broken open and dripping with blood, his bowl broken, and his outer robe ripped to shreds — went to the Blessed One. The Blessed One saw him coming from afar and on seeing him said to him: "Bear with it, brahman! Bear with it! The fruit of the kamma that would have burned you in hell for many years, many hundreds of years, many thousands of years, you are now experiencing in the here-&-now!"
Answer: You can't do anything with past karma. You can only change future. Future depends on how you act now. Do your best, and eventually you will be alright.
Answer: Your past fabrication / conditioning manifests as sensations in your body. But looking at the arising and passing away of sensations equanimously realising their impermanence you are effectively reducing the potency of the past Karma to take effect. More you do this, the past Karma gets weaker and weaker.
My being equanimous  and aware of the 3 marks of existence of sensations you stop adding fuel to the process of conditioning or the wheel of dependent origination turning. By adding not fue the existing fuel will burn and the fire will die out.
Also keep in mind that large portion of the result of Karma is our reaction to the effects and sensation of it which, creates a lot more problems and misery, and further fabrication which prolongs the suffering. The result of new fabrication and knock on problems we create for ourselves, (snowballing / avalanche effect) are much more than the effects coming from the past.
Answer: The Wheel of Knives is a lojung text in the Tibetan Buddhist tradition.
The pdf contains other content. The Wheel of Knives begins on Page 45
 you will have to scroll down.
An audio class on it can be found here.
Typed notes of this audio lecture can be found here Ctrl + F Wheel of Knives to jump to the specific section
A useful chart can be found here. It is in the reading as well, but in a less readable format.
The Tibetans believed that the purification of karma was possible.
The  Karmic Purification process has 4 steps. There is a class on that too on the same site. (acidharma.org)
I will provide a brief summary of the process.
The first step is to take refuge in the 3 jewels, in your knowledge of karma and emptiness. I will not go to into depth on this step.
The second step is called "Destruction Force"

To rip out the roots of something (with power). This is regret, not guilt. It is an intelligent, educated understanding that you just screwed up, based upon knowledge
  of karma and emptiness and how bakchaks work and are
  reaped. You know that you will suffer from what you did and
  why, karmically. You know you just caused yourself future
  suffering and regret it. You feel ill/bad.

You take the cause of the karma you are working with, remember all the times you did it, realize that it is going to cause you suffering. Regret that you commited the deeds in question.
The 3rd step is called "Restraint force"
Here you take the cause of the karma you are working with, and you restrain yourself from doing it again. The longer you can restrain yourself the better.

Restraint force. You don't do it again. Since we can't just stop
   cold for the rest of our lives, we need a plan. So we set a time
   restraint force limit to stop for awhile - not to do the deed for an hour, a day,
  a week, etc. and build up the time length to get used to the new
  habit of not doing the deed. For chronic habits, set a short time
  limit, say five minutes, and concentrate hard on not doing it. The
  mind can't concentrate tightly for longer periods to avoid the
  habit. If you break a vow of restraint, you are lying, and collect
  more bad karma, so keep the time realistic.

The last step is called "Applying the Antidote"
Using the chart, or in some cases logical reasoning, you determine the antidote to the karma you are working with. Stealing would have an antidote of generosity for example.
In this step you will have to think about your individual conditions.
If you think of karma like seeds, the idea is this, you stop watering the "bad" karmic seeds. You plant "good" seeds that are related to the "bad" seeds you wish to uproot.
In the case of killing, the antidote of protecting life should be applied. Getting and taking care of pets. Donating to disaster relief charities. Get creative, anything that prevents sickness and harm. Apply plenty of antidote, and try to keep the application up until the period you decided on in step 3 has passed.
Go through these steps multiple times if necessary.
One important thing to note:
Karma does not simply disappear, this purification process just speeds up the queue.

The karmic seeds you have are in a queue to ripen. The most powerful ones go to the
  front of the queue and are experienced first. They delay the other seeds from ripening
  until the powerful ones are done. ...  ...The result of purification is that the intention part of the karmic path is ripped out and
  dramatically lessens the ripening impact. Karma ripens into a lesser result.
  It's very important after purification to believe that you're clean - you're pure.

While working with these energies you will experience a period where the karma you are working with ripens quickly, the purification process is not easy, and you will experience suffering directly related to the karma you are working with.
To wrap this up a quick quote from the Diamond Cutter Sutra and one from Tai Situ Rinpoche.

O Subhuti, any son or daughter of noble family who takes up a sutra like this, or who holds it, or reads it, or comprehends it, will suffer. They will suffer
  intensely.
  Why is it so? Because, o Subhuti, such beings are purifying non-virtuous karma from the entire string of their previous lives, karma that would have
  taken them to the three lower realms. As they purify this karma, it causes them to suffer here in this life. As such they will succeed in cleaning away the
  karma of these non-virtuous deeds of their previous lifetimes, and they will as well achieve the enlightenment of a Buddha.
Tai Situ Rinpoche : Sometimes we do suffer intensely, when we are sick and so on. When we are sick we should resort to medicines and when we get into trouble with people we should try to get out of that trouble. Definitely. However, our attitude to the suffering and the trouble should not be one that defines them as solely negative. Suffering is like a broom that sweeps away the causes of suffering and when we understand this then the suffering is reduced to its true stature. Without the understanding it tends to become amplified to twice, ten or a hundred times its true size. The way we develop our understanding is to think, "The suffering that I am now experiencing is the result of previous karmic causes. Just as I do not want to suffer, neither does any being. Thus may this present suffering be of true benefit in removing the sufferings of all beings."
Comment: This is an exact duplicate of [this answer](http://buddhism.stackexchange.com/a/10385/254).
Comment: @ChrisW yes, I was not sure if cross posting was allowed. This question was linked in the other question and I thought that the answer worked well for both questions. If I need to remove it let me know.
Answer: The way to deal with past bad karma is doing the opposite, that is, doing good deed as many as you can. In Buddhism we can do good karma through body, speech and mind. If, for example, in the past you talk harshly to other, now you can talk kindly to other. Don't look at a deed and say it's just a small deed, just like a water drop by drop it will eventually fill a jug.
In your situation, what you need are patience and perseverance. You can do any good deed (fresh water) and refrain from bad deed (salty water). By continuing doing good deed all the time and refrain from doing bad deed, the salty water will eventually become pure.


Can someone (employee/freelancer) steal a Twitter account if you give them the password?

Question: How do you handle hiring someone to make tweets for your company but also keep the account secure?
Answer: You asked two questions..
Can someone (employee/freelancer) steal a Twitter account if you give them the password?
There is an option in Settings->Security and Privacy that will prevent someone from changing the password without out having 'personal information'. So that will protect you from having your password changed.
But they could change your username to something random, and then have some other twitter account take your initial username. Essential locking you out from it.
As for how you "prevent this from happening handle hiring someone to make tweets for your company but also keep the account secure?"

Hire people that do this as their day job
Lawyers.
Comment: I can't afford full-time employees or lawyers just for Twitter. I'm thinking about hourly freelance via ODesk. Basically random strangers. How do people deal with this? I looked at TweetDeck, but they still require the password to link to another account - I would still have to give out password.
Comment: Risk vs reward. Giving a random stranger your Twitter password sounds like high risk. Why not find an hourly freelancer who is local.
Answer: Ok I found it. Apparently that is a paid feature in HootSuite.
https://hootsuite.com/plans
However, I found a way around it for either HootSuite or TweetDeck. You can sign up for a throwaway Twitter account to do all the authentication yourself and add all the accounts that you need, then give out the password to the throwaway account. Since all the accounts are pre-authorized via OAuth tokens, the password is safe. The worst that can happen is someone could hack the throwaway and spew spam or such onto your linked accounts. At least the password will be safe. However, you will need an email address to create a new Twitter id, which is easy.
However, if you try to re-add the account, you will go through a lot of trouble because the services might say the account is already linked:

xxxx has already been added by another HootSuite user. Please add a different social network.

So you will have to de-activate the application and probably go through a bunch of other rigmarole.
Answer: I just did this. Set up a hootsuite account using a email address and password (not Twitter) and then from your account, add your twitter account. Now, you can give out your hootsuite email id and password out and they'd be able to manage your Twitter from the Hootsute web app.
I might be wrong or have not thought about it from different angles but it seems to be working. I checked it with all possible ways I could. It still lets me tweet and see the mentions and everything. Only thing is that you cannot delete the tweets you send out from Hootsuite.
Comment: I tried to set up HootSuite but I messed up and signed in with Twitter (or rather they messed up) and now am unable to log in because both accounts say they are managed by another account! What a mess! I tried to create a new account, but THEN I wasn't even able to change my email to my company because it said there was already an account for it, which I can't get into!!! I even tried reset password but it would not send an email! It was a frustrating steaming pile of mess. I set this up with TweetDeck though and now I'm able to see the account I want to control, so I can give out the buffer.


Did the Eastern Romans also use Roman concrete?

Question: When I read about Roman concrete I understand its use was forgotten after the fall of the Roman empire. But what about the Eastern Roman empire, the Byzantine Empire? Did they still make buildings with Roman concrete? This Wikipedia page, for example, does not refer to the use of concrete.
Comment: Do I read that correctly that you set the time-frame for this Q as after 500 and before 1500? Otherwise please clrify.
Comment: @LangLangC yes indeed, after 476 and before 1453.
Answer: The use of concrete did fade after the fall of the western Roman Empire, though
at least some aspects of the use of concrete was held over into the Byzantine Architectural style, on some early Byzantine works. A web page here shows an excerpt from a book on Architecture, A History of Architecture on the Comparative Method, by Sir Banister-Fletcher, New York, 1950, pp. 238, 240, 242. This says:

The system of construction in concrete and brickwork introduced by the
  Romans was adopted by the Byzantines. The carcase of concrete and
  brickwork was first completed and allowed to settle before the surface
  sheathing of unyielding marble slabs was added, and this independence
  of the component parts is characteristic of Byzantine construction.
  Brickwork, moreover. lent itself externally to decorative caprices in
  patterns and banding, and internally it was suitable for covering with
  marble, mosaic, and fresco decoration.

The style of decorative facing over the structural element was continued, but the structural concrete was phased out and replaced with structural stone or brick elements.
An earlier version (published 1905) of the above book can be read here and it has dozens of references to the use of concrete, several mentions concerning the use of concrete in Byzantine construction:
Page 212, in a discussion of characteristics of Byzantine Architecture:

D. Roofs. The method of roofing these buildings was by a series of
  domes formed in brick, stone, or concrete, with frequently no further
  external covering.

Page 194,

In fact no church was founded during this period in which mosaic was
  not intended to be employed, and the decoration of S. Sophia and the
  churches of Nicaea and Thessalonica show the perfection to which this
  was carried out. The core of the wall was generally of concrete, as in
  the Roman period, but the manner in which the bricks of the casing
  were arranged contributed greatly to the decoration of the exterior.

Also on page 194 is given an idea concerning the time frame for this transition from Roman towards more Byzantine construction styles:

The change from the old Roman forms was of course gradual, but in the
  course of 200 years the East asserted itself, and under Justinian, the
  Church of S. Sophia (A.D./532-537) was erected, and remains the
  greatest achievement in the style the interior being perhaps the most
  satisfactory of all domed examples.

Several discussions (here, and here) of the changeover from concrete-based structures to stone or brick based raise a couple of possible reasons:

Concrete was no longer necessary.
The use of concrete was at its peak during the construction of all the Roman 'mega' projects, things on the scale of the huge temples such as the Pantheon, public works such as the aqueducts, grand palaces for emperors, or displays of wealth and power such as the Colosseum.  The Byzantines did not build on such a vast scale such that the need to construct something so huge, so quickly, was not there.

The book Ancient Building Technology, Volume 3: Construction (2 vols)
By Wright, pg 235 seems to sum this up with a line:

For socio-economic reasons Roman Concrete construction was not
  appropriate or practical in Constantinople

Another earlier question on Roman concrete linked to a document here, which states the following:

Over the following two hundred years of the Empire, scale and material
  experimentation continued, though perhaps less markedly, with notable
  examples found in the Basilica of Maxentius (306; Figure 1.1) and the
  so-called 'Temple of Minerva Medica' (c.325).19 For roughly the last
  one hundred years of the Empire, the disintegrating central
  organization and shrinking building industry of the Empire could no
  longer provide the resources necessary for large-scale concrete
  construction.
  (Note says:Lanciani 1897 identifies re-claimed materials, particularly bricks, in both the Baths of Diocletian and
  Basilica of Maxentius.)

This implies that the Western Roman Empire itself had very limited use of concrete, for its last 100 years or so, and the Temple of Minerva in 325 may have been the last major concrete construction. (which agrees with the date of 330 in comments by @LangLangC). Again 'the disintegrating central
organization and shrinking building industry' would agree with 'socio-economic' issues making the use of concrete impractical.

The lack of volcanic ash.
One of the special components used in Roman concrete is volcanic ash, or pozzolana. The Roman source for this was close and convenient, Vesuvius. Without such a easily accessible source, it is possible concrete production was less economically viable.

The lack of pozzolana is also mentioned in a discussion of the transition from concrete to brick structures on page 97 of the 2014 book Earthen Architecture: Past, Present and Future

Byzantines probably didn't trust their concrete without pozzolana

Whatever the cause,  the use of concrete was not as prominent in the Byzantine Empire as the earlier, Western Roman Empire.
Comment: "Smaller scale" and the Walls or Hagia Sophia seem a bit at odds. – Have you found "concrete dates" for the transitions?
Comment: I new someone would bring up the Hagia Sophia... By smaller scale I meant the overall volume of construction projects... and as to (ahem) dates, the only references I found to actual concrete use in byzantine structure were from Bannister-Fletcher, and he just lumps concrete in on the materials used in a couple of churches, which were from the 5th and 8th centuries. They weren't very specific as to *how* it was used. I'll see if I can relocate to entries and update the answer with specifics.
Comment: Flicking thru my old scripts I only found the unsourced "Roman concrete stopped to be used after 330" – before the West went down, and despite caementitium, incertum  and testaceum being used well after that. More modern dating/timeline would be a great find.
Comment: I edited in a little more info, but most of this books entries were vague, concerning/claiming general use. He seems to give a transition time of by Justinian, 532, but this is definitely not  'more modern'  information...(I think the original publication must have been in the 1800s)
Comment: Have you access to Gerold Eßer (Vienna) or the full account in ["Nuts&Bolts of Construction History"](https://books.google.de/books/about/Nuts_Bolts_of_Construction_History.html?id=hCQsmQEACAAJ&redir_esc=y)? My limited access promises sth.
Comment: Found a PDF[here](https://publik.tuwien.ac.at/files/PubDat_215158.pdf) which might be the Gerold Eßer article you are referenceing. *Reading...*
Comment: Let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/72651/discussion-between-justcal-and-langlangc).
Comment: The Romans were aware of, but didn't know how to duplicate, the importance of *pozzolana* in their concrete. Only in the past few years have modern engineers begun to measure and replicate its properties.
Comment: i think the answer could be slightly improved by pointing out that "S. Sophia" is better know under the name Hagia Sophia.


Can I successfully freeze raw cabbage?

Question: How long will an half of raw cabbage last in the freezer? Had leftover after making stuffed cabbage rolls, will be making corned beef & cabbage for St. Paddy's Day. Will it make it?
Comment: Is it half a head or is it already cut up? To be honest, if it's still a half of a head, I think it would likely be fine in the fridge though you'll want to re-cut the open side.
Comment: Chop it up. Add some salt. Stuff it in a jar and sauerkraut will appear. That's my go to for leftover cabbage (the technique is as old as time). Search 'lacto sauerkraut' if that tickles your fancy.
Comment: Hi Catija... It's half an head. I'm fortunate to have a great grocery store whose produce is fab.. (huge & fresh).. So I only needed half of it for my dinner & that's after shredding some for the bedding of casserole dish.. which is optional... So, you think it'll last in fridge until 3/15, 16 or 17th?? I can wedge it, shred it or whatever.. Just don't want it dying a slow death in my crisper:-D
Answer: You can freeze raw cabbage and keep it for months, however it's not good for the texture as freezing damages the structure. You're better off keeping it in the fridge or just using it. It may make it to St. Patrick's day in the fridge but it will lose some flavor, I'd suggest using it and buying more then.
Answer: You can freeze cabbage after you blanch it. I do, but I like cooked cabbage. It will change it a little. It's a little tougher but still taste great. Can only be used for cooking. I cut mine to the size I want before the freezing process. Hope this helps.
Answer: I wouldn't suggest freezing cabbage raw.  You're better off quartering and blanching it.
For the 2 weeks that you're looking at 'til St. Patricks day, if it hasn't already spent months at the store, you should be fine with it in the fridge, wrapped in plastic.
(although cabbage is useful & cheap enough item that it's worth using what you have and buying another head next week ... or buy brussel sprouts if you want an easier way to get a specific quantity of cabbage without waste.)
Answer: I cut out the hard end of the core, then wrap in plastic wrap and freeze whole cabbage. Thaw and peel off limp leaves for stuffed cabbage rolls. No blanching needed. I add about 5-10 extra minutes cooking time to the cabbage rolls.
Answer: Cabbage stored in a freezer tends to be watery and limp when thawed. We would never store cabbage in our freezers.
Answer: Freezing cabbage only makes it limp & wet, because the cells contain water, and you know what happens when water freezes...it expands, and would burst the cells in the cabbage, creating watery & limp cabbage when thawed. My Mom used to freeze tomatoes... run them under warm water & the skin would rub right off, once the tomato was all thawed, She would "core" it & serve cold like diced tomatoes out of a can with salt & pepper & no lost flavor!

Can I successfully freeze raw cabbage?


Process vs Method

Question: When describing a series of actions or steps to be performed:  What is the thought process that 'tips the scale' in one direction or the other, when trying decide if it is a process or a method?
Comment: http://www.epo.org/law-practice/legal-texts/html/guidelines/e/f_iv_4.htm 4.12 and 4.13 might be an interesting reading for you
Answer: There are actually only two claim categories, you either claim a physical entity (product, apparatus) or a physical activity (method, process, use), as outlined in decision G 2/88 of the Enlarged Board of Appeals of the EPO. You can find it here: http://www.epo.org/law-practice/case-law-appeals/eba/number.html
In my field (chemistry) we usually claim a process for preparing a chemical compound. But we also claim a method of preparation of a chemical compound. The scope of the claim is pretty much the same, as you can imagine, but the expression "process" is shorter that "method of preparation" and thus sounds more elegant. You really want to draft claims with as much less words as possible!
And I have not see any examiners either in EPO (Europe) or in the US objecting about a using the word method vs process. I would dare to say that it mainly depends on the technical field in combination with adequate knowledge of the (English here) language.
Comment: @gatorback yes, exactly. I am not sure what your work exactly is, but if you are at the beginning of your patent drafting education, it's a good idea to read the examination of other patent examinations from your field to see what other people do!
Comment: Good comments: If I may distill the essence: anticipate the lexicon of your target audience.
Comment: @gatorback alternative essence: do whatever floats your goat ;)
Answer: I may be missing something, but I am not sure why this would matter?  Both process and method claims would fall under the statutory (35 USC 101) category of "process".
The only place it would seem to matter is w.r.t. to "product by process" claims as DonQuiKong points out.  In this case, you would not be claiming the method/process, but the physical outcome as defined by the method/process, and thus this sort of claim would probably fall under the statutory category of "composition of matter" or "manufacture".
Comment: I had to choose one of the terms and wanted to understand what the different lines of the thought that could enable one to arrive at a decision
Comment: I do not know of any distinction between the terms.

Process vs Method


Creating a TCG - Checking Mechanics

Question: I have created a very simple card game but I am worried some of the mechanics may be shared with others.
Is there anywhere I can check this, and what would be the outcome if other games did share the mechanic?
Answer: Note: I Am Not A Lawyer, this is mostly just accumulated internet knowledge, and may be inaccurate.
Card game mechanics are patentable. This means your mechanics could be already be patented by another company.

A patent protects a unique invention or process. It protects it by preventing someone else from duplicating your invention/process for a period of time (typically 20 years).
Yes, Richard Garfield patented tapping. The patent, by my reading, runs out on June 22 of this year (2014). Wizards went back and tacked on some other parts to that same patent, which you can read here. The patent covers just about everything you could imagine in a TCG. It covers building decks, casting spells, the process of trading with others and more.
Wizards is saying that Hex violates a lot of its patents. Hex probably does. Here's the problem:
Those patent claims are beatable.
For example, they might be too abstract. They might be too broad. Having a patent does not guarantee that it will be valid in the face of someone challenging it. And importantly, if they run out when I think they will, Hex/Crypto can limit the damages they pay out to only the infringing time. After that, Hex isn't infringing on any sort of patents held by Wizards. They're probably still infringing on all the patents that early adopters lined up on the internet regarding downloads, backups, dropboxes and other horror stories. Litigating patents takes an incredible amount of money, especially when you're trying to get it declared invalid one way or another.
Source

While your game is in development/playtesting, this is not a big deal, as you're not charging money, and so the worst you could expect would be to be told to stop.*
Once that changes and you're actually trying to charge for this stuff, you should seek actual professional paid-for advice. Apart from anything else, you should consult a lawyer about starting a company to control the game, so that in the event of lawsuits or contracts, only the assets of the company will be liable.
*: Warning: I may be completely wrong about this.
Comment: I have selected your answer as it has helped me a lot with my research. Thank you so much.
Comment: Thank you for your answer, it has opened up some topics for me to research.
Answer: Google has a way to search for patents. https://www.google.ca/?tbm=pts&gws_rd=cr,ssl&ei=92GlVb5Jwct6juip0Aw
But as mentioned before, professional help might be the best. When it comes to things of a legal nature, don't assume you know the answers. Do what you do best and rely on others to do their thing.
As a side piece (which could be useful to @deworde), there's a difference between a sole-proprietor and incorporation for a company, which comes with different legal protections and obligations. Make sure you speak to a proper lawyer before making major decisions like these. :)
Comment: An issue I have when trying to find patents is that I have no idea what they would be called. E.g tapping.. I only found the name by chance.
Answer: It's actually unclear if game mechanics are still patent eligible in the US after the 2013 Alice ruling.  (Game mechanics have traditionally been protected by patent, but now there is a question as to whether they are "abstract" and therefore not patentable. If this is the case, it probably violates the "spirit" of US intellectual property law, because if game mechanics are no longer patentable, there is no intellectual property protection for games, in that all game are abstract--artwork and characters, which are protected by copyright, are artistic elements, and do not constitute game IP.)
I'd have to do more research on the Hex/WOC case, although if the patent itself wasn't challenged and overturned, that's a good sign for game developer in general.  (i.e. it means if you develop truly novel mechanics, and patent them, they can be indiscriminately stolen by cloners as in the case of the 2048 puzzle.)
The underlying issue you bring up is indeed a problem.
When I was preparing to patent my own set of completely novel game mechanics, I did exhaustive searches for similar games.  In my case, no such games existed, but that is a factor of an entirely novel set of core mechanics, which isn't the condition for card games.
The other problem is the popularity of card games--there are so many of them!
However, any mechanics that are in the public domain, either because they were made public before seeking patent protection (with a minor caveat of a 1 year grace period) or because the patent expired, as with Magic the Gathering, can be freely used.

You can restrict your search of card game mechanics only to patent documents, which significantly narrows your search
If you don't find the mechanics in an granted patent that is still within the 2 year protection term, or a patent application still waiting for review, there shouldn't be a problem.

PS Google Patents is the best place to look. USPTO database is rather flaky!  If you have any followup questions or require clarifications, don't hesitate to ask.  This very issues is a preoccupation.
Comment: The Hex/WotC case settled, so there was no ruling on the merits of the case.
Comment: @bwarner thanks for that info.  IP cases are known to be "ruinously expensive" and so are generally settled.  But the uncertainty regarding current patentability of game mechanics is very much an open question. (If they are no longer eligible, it would be an unintended consequence of changes to the interpretation of the law starting with Alice.)

Creating a TCG - Checking Mechanics


Why doesn't a table sublimate, while ice does?

Question: A table does not sublimate, and nor does a spoon. Ice does, however. What is the fundamental difference?
Comment: At high enough temperature and low enough pressure, a metal spoon will definitely sublimate! A wooden table is a more complicated substance, wood will tend to decompose (or burn if oxygen is present) before it sublimates.
Answer: This relates to the difference between how ice, iron spoons and wooden tables stick together.
In wood, most or all of the bonds between the individual atoms and fibre units are covalent; making them very strong. Similarly, a spoon is an alloy of iron, nickel, chrome and carbon, also a very coherent structure.
In ice, on the other hand, the units of the crystal is held together with comparatively weak hydrogen bonds, meaning that not a lot of energy is required for a surface molecule of water to escape, in a process called sublimation.
Usually, once a water molecule escapes the ice, it is, given a relatively constant temperature, very unlikely to rejoin the body of ice; meaning that especially in open air and windy conditions, ice will sublimate at sub-zero temperatures, although as the temperature of the ice drops, this effect becomes steadily less noticeable.
Edit: It is worth noting that given enough time, a table or a spoon can indeed sublimate as well, at any temperature, but the odds against it are utterly staggering.
Comment: I'm not sure whether "odds against it" is a good description here (but I'm not a native English speaker): odds against it to me sounds like a small chance that the spoon evaporates - whereas I'd describe it as an extremely slow process, which however wouldn't be subject to a chance whether it happens or not: I'd say it happens, just far to slow to play any practical role.
Comment: @cbeleites: Fair point; but given enough time the spoon *will* evaporate, but odds are, before that happens, it'll be destroyed by some other means; like the sun exploding.
Comment: You might want to read the [prohibition on cadmium plating](http://nepp.nasa.gov/npsl/prohibited/cadmium_prohibition.htm) in space by NASA: "Cadmium is known to sublimate in a hard vacuum environment (especially at temperatures above 75°C). The sublimation products, which are conductive, can redeposit resulting in short circuits. The sublimation products may also interfere with sensitive optics."
Comment: @WillihamTotland I find this fascinating.  You note that as the temperature of the ice drops, the sublimation effect becomes less noticeable.  Presumably the effect would be greatest in a block of ice just below freezing.  What about the iron spoon? If we heated it up to just below its melting point, would we able to observe the effect?
Comment: @emory: The conditions under which steel (or iron) sublimates are fairly peculiar. Even in the extremely harsh conditions of interstellar space ablation resulting from impacts with stray hydrogen nuclei is likely to be a far bigger factor in mass loss than sublimation.
Comment: I think when you say "evaporate" (4th paragraph) you mean to say "sublime", as you did before.
Comment: @MarcvanLeeuwen: Indeed, fixed.
Comment: @WillihamTotland: That was really fast (the edit appeared just when I finished my comment)! By the way I am confused about the verb corresponding to sublimation; I was tempted to use "sublimate", but WP uses "sublime".
Comment: @MarcvanLeeuwen: As far as I know, either is fine.
Answer: One term I'm missing so far in the discussion is the vapor pressure.
You may say that the water vapor pressure above ice is far higher than the iron vapor pressure above iron  (at "normal" temperatures), or the vapor pressure of the various substances forming the table over that table.

See here for the water vapor pressure. I take from the diagram that at -20 °C, the water vapor pressure above ice is approximately 1 mbar $\approx$ 1 hPa, and at slightly below 0°C, about 7 mbar.

According to this table in Wikipedia, you need to heat iron well above the melting point to reach such iron vapor pressures. They also cite a formula for the iron vapor pressure above solid iron:

$\log (P/\mathrm{Pa}) = 12.106 - 21723 / (T/\mathrm{K}) + 0.4536~\log (T/\mathrm{K}) - 0.5846 (T/\mathrm{K})^{-3}$
with the specification that this could be used from 298 K upwards.

Plugging in 298 K, I get $p_{Fe} \approx 10^{-60}$ Pa.
This is so low that lots of other processes will lead to more substantial loss of iron from the spoon via the gas phase (e.g. according to this $\ce{FeCl3}$ has a vapor pressure of 1 mmHg $\approx$ 133 hPa at 194 °C).
Answer: << This answer was posted before the question was completely rephrased and originally asked "why does a table not evaporate" >>
Who said a spoon doesn't evaporate?
Ice is a solid below its melting point ($0~^\circ\mathrm{C}$) but above its melting point it goes through a phase transition and melts to become a liquid (so it's liquid at room temp). Then when it's heated above room temperature to its boiling point ($100~^\circ\mathrm{C}$), it goes through another phase transition and it evaporates to become gas.
Iron (assuming an iron spoon here to keep it simple) is a solid (at room temperature) then when it's heated above room temperature to its melting point ($1538~^\circ\mathrm{C}$) it becomes a liquid.  Then when it's heated above its melting point to its boiling point ($\approx2861~^\circ\mathrm{C}$), it evaporates.
Comment: Hm, maybe I use a wrong english word?.. Maybe I meen _sublimation_ here?
Comment: This answer increases the confusion created by the language issue in the question.  It would probably be best to remove it.  The question is not about evaporation of a material once it reaches that material's boiling point, but evaporation that happens during a material's normally solid state.  It should be clear that he wasn't talking about boiling water when he said that ice "evaporates".  He is talking about submlimation, where a solid goes straight to the gas phase.  A detailed explanation of what he wasn't talking about is not helpful.
Comment: But wait, maybe I was unclear, but doesn't ice evaporate even in a fridge?.. Of course everything can evaporate given a high temperature.
Comment: @roman.brodetski: not sure about the English terms, but yes, there is a water vapor pressure above ice as well, in fridge and freezer


data rate with a FSK modulation

Question: With a BPSK modulation the data rate is $D=\frac{1}{T_s}$ where $T_s$ is the symbol time. But for a BFSK modulation, how do we find the data rate?
Answer: In general, the data rate in bits per second is the symbol rate times the number of bits per symbol; independent of the modulation used.
The B in both BPSK and BFSK stands for binary, so there is 1 bit per symbol, or 2 possible symbols (2 possible phases or frequencies depending on the case).
So the data rate in both cases is the same.

data rate with a FSK modulation