How can someone access data that I am requesting when I use HTTP?

Question: I have heard that HTTP use plain text communication. If it is so how can a hacker or someone tap it. From my little knowledge I know that if we sent a request to a web server it replies back to us using our IP address. So if an attacker wants to know what I am doing, how does he do it? Is it necessary to know my IP address or does he intercept it in between? Or is it like this: an attacker decides to attack someone and he picks some data and he finds that this belong to say X, which means does he attack randomly?
Comment: Pretty certain this one has been done before. Have a search through the questions tagged mitm
Comment: @RoryAlsop I think this question asks something extra "can hackers sniff my data without my IP?"
Answer: When you access a website, say Google, your request goes through multiple steps (nodes) until it reaches its final destination. The first node is your home router, then your ISP's routers, and then other big routers, and then Google's routers. At any of these nodes, your request is momentarily stored in the devices' memory, which means it can be accessed by an attacker. Of course, that's not a very likely situation.
The bad news is that an attacker could somehow trick your computer into thinking that his computer is a real node in the path between you and a legitimate node. This attack is called a man-in-the-middle (MiTM) attack. MiTM come in many shapes and forms, the most famous ones are:

ARP Spoofing
DNS Cache Poisoning
DHCP Spoofing

I won't go through each type because it will make this answer too big, but please have a look at pages and learn more about these attacks.
As a solution to this problem, we have HTTPS. It works by layering HTTP over SSL/TLS to make sure that your request is going from your browser to the intended server and making sure that anyone snooping around won't be able to see what the request or response you get from the server contain.
Comment: @NithinJose  Just because something is encrypted or uses cryptography doesn't mean it's safe.  Cryptography is hard and often has problems in it... hackers find ways to get around that.. and those reasons are listed above.
Comment: I think https use cryptography. So will there be some key shared by web server and user? Could the attacker act like being the user?
Answer: Not completely necessary. If the attacker is using ARP spoofing1, he can be sitting anywhere in the chain of communication2. For example, if he's connecting to the same ISP node as you are (physically near you), then he can sniff all the plaintext data of everyone connecting to the ISP in that subnet. He doesn't need to know your IP for this, however he will find out who sent the HTTP request. So he doesn't need to find out your exact IP or do random shots-in-the-dark until he does find it; he can very easily just fetch all packets from your subnet and sift through those.
Note that an attacker can choose to ARP spoof only you, if he does know your IP. This is much more convenient a there's less unwanted noise on the line, but he can just as well spoof everyone on the subnet and proceed.

The way this works is that the TCP/IP protocol (well, the ARP protocol) is inherently insecure. When data needs to be sent to a certain IP, the computer with that IP is asked to identify itself. It's an easy matter to pretend to be that computer and accept the packets, and then forward them on to the real recipient.
For this, the attacker needs to be on the same subnetwork as a node which is transmitting the data. This node could be you, an intermediate ISP node, or the web server.
1. This is not the only way to MITM, see Adnan's answer for more. All three of those methods can work without knowing the exact IP.
2. It is very unlikely that an attacker is sitting between two intermediate nodes. It is very easy for an attacker to be sitting on the you-(your)ISP connection and not too unlikely for the web host-(their)ISP connection. Anything else is very improbable.
Answer: I just wanted to answer your question on whether there is some shared key(can't comment because not enough rep).
When you use HTTPS you will be using SSL for encryption. Servers that support HTTPS will have certificates which hold their public key and also can be used for verification. Clients will use the public key to encrypt a pre master secret to send to the server. Afterwards, they both will use that pre master secret to generate the master secret key for a symmetric encryption scheme(one where they use the same key to encrypt and decrypt data).
Hope that helps!
Edit:
To answer your last question of whether an attacker could pretend to be a user: of course! It's pretty trivial for an attacker to establish an https connection to a server. However, this should not allow the attacker to be able to read messages from other users using https, because their secret keys will be different.


Too much cayenne chilli pepper

Question: I have added cayenne chilli pepper, instead of cayenne pepper, and (I think too much) to my green tomato chutney.
How can I reduce the spice and still be able to store the chutney?
Answer: There are two traditional ways to reduce the hotness of excess chilli.
First, excessive spicy taste is can be neutralized by adding appropriate filler/absorbent ingredients to the mixture. Fresh coconut shreds are commonly used to absorb the excess chilli in chutneys.
Second, you can add sweet and/or sour substances to counter the feeling of hotness. Traditional sour additions to chutney can be:

Tamarind (common)
Tomatoes
Lime or lemon
Vinegar

Typical sweet alternatives are:

Honey
Brown sugar

All these additions may change the flavor and shelf life of the chutney, but you can always experiment. If that is not desirable, just add more of the other recipe ingredients to increase the number of servings.
Answer: Try adding some oil and letting the capsaicin dissolve in the oil, then pour off the oil.  Of course, you won't get all the oil and many other flavor molecules will dissolve in the oil as well.

Too much cayenne chilli pepper


Changing old doorbell transformer

Question: I'm replacing an old doorbell transformer. After removing the junction box, I have 3 exposed black wires. I have the new transformer with the typical White, Black, Green wiring, but I don't know which wires - if any - to connect the green. I added a photo. Any help would be appreciated.
Comment: How about vacuuming/cleaning all the crud out of the box so you can see what you're looking at?  The condition of some of those wires looks dangerous, and may need some more attention to be rendered safe, *but you can't see to tell*.  Was this box covered with insulation?
Comment: I can't tell on the old stuff whether green is discoloration of some sort or green insulation == ground wire. But on any **new** device with black/white green, the green wire should be ground and connected to other grounds and/or (if you have a metal box and metal conduit that is part of the grounding system) screwed to the box.
Comment: The wires are in terrible shape. The green you see there is some sort or erosion. My old transformer doesn't have the ground wire. Assuming that means the box is grounded? Could I cap off the ground and wire bolt the like colors together? Some of my questions may come off ignorant, first go round with electrical work here.
Comment: If the box is grounded then any ground wires should be screwed to the box. Wire nutting like colors together is *generally* the right thing to do, but there can be exceptions. In addition to the corrosion, I'm concerned about the existing bunch of white (presumably neutrals) taped together - if they are simply twisted together under the tape instead of nutted then they should get a proper wire nut.
Comment: It was, yes. Sorry, the pic was taken immediately after removing the junction box.
Answer: The bare grounds are buried in the bottom of the box there
Since these are NM-type cables we're dealing with here, the ground wires in the box will be bare wires, and lo and behold, there's a whole bundle of them improperly spliced together in the bottom of the box.  Take a suitably sized wirenut and nut the green wire on your transformer to that bundle of bare wires (this will also properly splice the bare grounds to each other).
As to the hots and neutrals
The black wires in this box are all hot, and the white wires are all neutral (otherwise, there'd be a white spliced to something that isn't white, that's a clue that shenanigans are afoot).  So, in this case, it's black nutted to black, white nutted with whites (and you may wish to replace the splice of the existing neutrals with a proper one while you're at it), and grounds as above.
Comment: Appreciate the help. I see the wires you are talking about. I went to check the breaker box before going back up to the attic to connect the new transformer. Looks like whatever I did yesterday, tripped the breaker and it won't go to the on position. What is the correct wiring here - outside of the already mentioned ground to the bundle on the bottom -  Am I connecting the 3 blacks + the black from the new transformer all in one nut? Again, thanks for the advice.

Changing old doorbell transformer


Widget to use for "diversity" forms

Question: I've just filled in a form where I had to describe my race with one of three radio buttons

"White"
"Black"
"prefer not to say"

(sarcasm) Good thing I'm not Han Chinese then. (/sarcasm) The questions for gender identity and sexual orientation were not much better. It made me think about how one would do this right. I'll try and phrase this as a design question rather than an identity politics one.
I'm looking for a control/widget (for web forms) that meets the following requirements

You can enter free-form text if you want to. It must be clear that you can do this and that this is an acceptable option, not an "if you really must".
Most people will want to select from one of 2-10 predefined options. This should be made as easy as possible, ideally 1 or 2 clicks.
For the majority who are fine with one of the defaults, I want to encourage them to select one of those rather than type their own thing that I have to normalise later (e.g. "straight", "hetero", "heterosexual" are all the same category).

On windows there's controls for this kind of thing, described for example on MSDN here - for example the drop-down

I also like the design approach of the date fields on the GWR trains page - when you click or tab into these form fields, a selector widget (e.g. calendar) pops up. But in both these cases, it's not clear at a glance that some standard options will pop up when you select the field and you could think that you have to type something, at which point people may wonder if straight or hetero is the "correct" thing to type before they even reach the field.
What kind of control should I use in this situation?
Answer:
This should be made as easy as possible, ideally 1 or 2 clicks.

Quick side note: the number of clicks isn't necessarily any indication of 'easy to use'.
As for your question, I believe there is a fairly standard pattern for this already. It's typically a drop down or radio button list with one option being 'other'. For less than 10 options, I'd probably go with radios:
<code>( ) Option 1
( ) Option 2
( ) Option 3
( ) Other
</code>
If they choose 'other' I'd then reveal a field to enter the text:
<code>( ) Option 1
( ) Option 2
( ) Option 3
(•) Other
    Enter your option: [                          ]
</code>
As for encouraging them to pick a pre-defined one over the text one, that's a bit trickier. I'd suggest you likely can't from a UI standpoint. The key will be more of a content challenge...making sure the defaults cover most of the bases.
If you have to normalize the data, then I'd probably argue you not allow free form text to begin with. That said, identifying one's race and/or sexual identity isn't really data that's easily normalized to begin with, so may be futile to even try.

Widget to use for "diversity" forms


What are the most important considerations when designing a database?

Question: I would like to know from the experienced programmers what they consider to be the most important considerations when designing a new database.
Answer: First off and most important learn and understand the business domain.
1) Are you looking at a high transaction rate like a busy web site, or low use like a a small company HR system
2) Is security a big issue - are you handling personal details, or financial data. Or is it just a product catalogue
3) Will your users be doing many updates/inserts or is it mainly read only
4) How many users, what are the usage patterns (peak load or evenly distributed)
5) Do you need 24x7, 16x5 or other uptime, 24x7 is much harder to do as you have no down time for maintenance
6) How big is the DB going to go? If it's really big you'll have to design your tables to take account of that and/or partition
7) Do you need to look at enterprise cluster with hot fail over, or just normal hosting
8) How will the DB be adminstered, in most DB projects 95% of the effort is spent developing for the users and their applications, DB admin is forgotten
9) DB Admin, from previous includes backups, changes to other systems, integration to other systems, data loading
10) Actually Data loading and using existing data is another big issue in its own right.
That's it for a start
Comment: Security, performance, availability... but data integrity and accurately modelling the UoD don't even make your 10 "most important" things :(
Comment: Its all about well-formed, clean, entity model.
Answer: The database is secondary to your business process design and should cleanly support your business process in a direct and simple way. You will gain far more benefit from a well-formed, clean, entity model than you will from an index here and there. So once your process is defined, you take it and split it up into "entities" as cleanly as possible with relations that make sense. Once you know your entities, they translate into database tables.
One of the most important things to do is to not overarchitect.
To give you an answer with some teeth, let's take a "vehicle" entity as an example. A vehicle has multiple wheels. You have a critical decision to make knowing that there will be multiple wheels attached to the vehicle. You have 2 choices to make - You can make "wheels" a separate entity, or you can make "number of wheels" an integer field in the "Vehicle" entity.
If you absolutely know that you will need to store lots of changing information about each wheel, then create a "Wheel" entity. You now have a relationship between entities (the car and the wheel).
If not, a simple field will do just fine.
Thinking through these critical decisions and making things as simple as possible is by far the most important thing for me when designing a database. It can make the difference between things being really easy and really difficult when you build the next layer(s) of your application.
Comment: Very descriptive answer. well-formed, clean, entity model
Answer: 1 - Consistency
Over time your database will change and other people will need to work with it. Do yourself and them a favor and make sure that the structures are named in such a way that any reasonable person with basic domain knowledge will be able to anticipate the contents of the table. Take the time to write down (could be a simple as notepad) some basic constructs that you use.
Examples:

Primary keys all start with IdTableName
Casing of table names is Pascal
Foreign keys are all TableNameId
ext...

Whether you choose to use underscores or not (substitute any other conversion for underscores) doesn't really matter at the end of the day as long as you are consistent in the way that you use or don't use them.
Your database is the last line of defense for data integrity. Do all of your data access through stored procedures and enforce the integrity of the data by using check constraints, foreign keys and so on. Type the data correctly, don't use VARCHAR(50) when CHAR(5) is more specific and accurate.
Someone else mentioned something about keeping it simple. Last but not least don't build something because you "think" you will need it next month. Things change quickly and you will end up doing more maintenance on stuff you "thought" you were going to use rather than things that you are using if you fill your database will stuff that serves no purpose.
Answer: Fidelity with the real world entities that the database is supposed to model.
Comment: +1 if you don't have that, you will have a mess that will never work right.
Answer: I'd personally suggest picking up or borrowing a copy of "Database Design for Mere Mortals". Everything you'd ever need to consider in designing a database would be listed in that book, and it's in a very methodical and logical order in which you can build out the database. The Table and Column definitions are tedious, but worth every minute used in the end.
I believe you might be able to read the first chapter if the book via Google Books or via the page preview on Amazon.com.
There are some tidbits you can learn over time or from this site as 'best practices', but nothing beats designing it from the ground up the correct way on the first try.
Answer: A basic set of points:

Determine the purpose of your system.
Identify the entities that your system will need.
Identify which information each entity should provide.
Identify the exiting relationships between your entities
What would the user want to know about and do with your data.
Conceptual and Logical Database Design
Normalization and ERD
Identify fields with unique values.
Select the appropriate data types for your fields.
Database refactoring.
Answer: Know your data.
Answer: you also have to understand what the database will be used for. if it's for transactions (OLTP), it should be as normalised as possible, and the goal is for transactions to be completed as quickly as possible. if it's for analysis and/or reporting (OLAP), it should be denormalised in many places where you'll be performing aggregation. design considerations for OLTP databases are not applicable to OLAP databases, and vice-versa.
Answer: who's going to build and maintain it, where , how and with what. DO you have methods and procedures and processes for doing this or just winging it.
Certainly the Business needs drive the data needed which should be captured in an implementation independent ERD.
But, you also have to think about who will maintain the data over time.
As well as who "owns" the data. Who owns entity and attribute definitions.
Answer: The information requirements are the most important part.
This is another way of saying "determine the purpose of your system", from a response provided by CMS.
Conceptual data modeling is just an organized way of collecting and presenting the information requirements.  Every value stored and served up by the database is connected to an attribute, and every attribute to a domain.  Attributes, in turn, describe either entities or relationships among entities.  Subject matter entities and relationships make up the conceptual structure of the "real world" that the data describes.  Building an ERD from a conceptual model is easy, although tedious.
After that, you can pick a DBMS, design the logical database, design the physical database, and build.  At each step, the decisions you make are more reversible, due to data independence. Data independence encapsulates design decisions inside the database, except for performance consequences.  You have to know your tool, of course.
Having a tool for managing models, and converting them to diagrams and scripts can be very helpful at speeding this process up, and cutting down on errors.
But if you have serious errors or omissions in your information requirments, no amount of clever design or implementation is going to make up for that.
Answer: A good database can be judged as follows:
If a database is properly designed, you should be able to understand how a business operates by looking at nothing more then the schema.
In other words, the database is the business.  If the database isn't reflecting how the business is run, either the database is wrong or the business is wrong.
The database is also one of the few things that you really, really need to nail upfront.  You can always fix bad code, but rarely can you back out of a bad schema change.  Make sure to do it right.
Answer:
Naming Conventions: stick to one set of rules
Normalization: (extent of normalization) - this will depend of number of read vs number of updates comparison of a data entity.
Relational Integrity and other constraints: some people advocate the use of Foreign Keys while some don't, but you've to choose that based on your requirement and your personal preference as it is a big debate but I would always choose to use FKs
Creating database diagrams, analyze and discuss with the team if possible.


Is it possible for people with a stutter to have a career in academia?

Question: I understand that it is difficult for people with stuttering to verbally communicate and explain their ideas/research or to give lectures. Does that mean there is no chance for them to work in academia, even with a PhD degree?
Comment: One of my professors right now has a stutter but is nonetheless a fantastic verbal communicator (and lecturer). He is clearly productive. The case may be different with you, but my prof demonstrates that for some people its just another thing that can be worked past.
Comment: If [popular entertainers and successful business leaders](http://www.stutteringhelp.org/famous-people-who-stutter) (where arguable, the ability to articulate clearly is a larger part of their job than academia where research results can be more important than articulation) manage to achieve success despite varying levels of stuttering, there's no reason why stuttering should prevent success in academia.
Comment: Of course you can.  Just do it.  If you sit down and try to think about why you will fail, you will definitely find 100 reasons.  But if you go for it, and do whatever is necessary, you will succeed.
Comment: The answer to your question is no. However there will clearly be some things that are more difficult with a stutter than without. But that is of course true in general (I have unreadable handwriting for example).  Some people are blind etc etc. Don't let it put people off.
Comment: I had a professor with a stutter in graduate school. He was brilliant logician; provided directed studies, materials, and wrote me several letters of recommendation. I don't think his stutter mattered that much, it was like having a thick accent; after awhile I didn't even notice he had one.
Comment: I once had a lecturer who was born without any arms. If he can do it, you can too!
Comment: I had a lecturer (but around 15 years ago) who - around in the middle of the course - changed his language to Russian (in a country with no connection to the Russian language) and refused to teach in a local language/English. He is still active in Acadmia! If he can, you too.
Comment: @l3x, it's been eight years. How did things turn out for you and what did you find?
Answer: I don't want to turn this into an answer about how universities or society in general should deal with disabilities.  I will offer what I have witnessed first hand through a good friend.
Can you work in Academia?
Yes.
Will people make fun of you?
Probably but who cares.  People make fun of others for everything.
But...

don't try to hide your problem
embrace the stuttering.  Nobody cares that much unless you do.
spit out what you are trying to say.  The content and meaning are key.  Don't let the stuttering stop your speech.
don't try to dumb down your words to help the stuttering (to a point).  You will be judged by most on what you say, don't let stuttering get in the way of that.

So my friend - let's call him Paul (sorry Paul for using your real name) had a big banquet speech he was asked to do after much of his research was published.  Four of the faculty members/advisors Paul was thanking were named John...  So he says, "I would like to thank Joh-Joh-Joh-Joh-Joh-Joh-John.  (He catches his breathe and smiles at the crowd).  Well I had fou-fou-four Johns and I think I thanked too many."  It could have been two hours of drinking but people were honestly laughing for two minutes straight.
In reality it probably would effect you more if you were in a field were public speaking were part of the field.  Paul was a scientist.  I hate to say this but I think the stuttering became his calling card and made him even more likable, and even better presenter.
Add:  After seeing this question get a ton of hits I want to be clarify my answer.  Stuttering and other issues, whether it is a disability or just something that someone isn't good at - be honest with yourself about any "shortcomings" and don't make others feel awkward (I know this is hard).  Whether it is a strong accent, stuttering, talking low, saying "ummmm", whatever - if you know you have an issue own it and put your audience at ease.
A perfect example of this is Jeff Foxworthy.  He readily admits that he talks like a redneck.  That is his shtick.  People like him and think he's hilarious because he openly talks about his accent and redneckedness.  If he came out to an audience, unknown to them, and tried to (poorly) hide his accent and redneck background, people would feel uncomfortable.   Everyone has issues, some worse than others.  Acknowledging your issues makes your more personable and relateable to your audience as they know that they too might have trouble talking in front of a large group.
Comment: @enthdegree Your experience has been a blessedly charmed one to not have to endure such a thing, either on the receiving end, bystander/witness, or otherwise - or the cruelty was so subtle and pervasive that it evaded notice. Physical or mental disability, illness, accent, hair color, eye color, skin color, height, weight, gender, sexual orientation, what you drink, whether or not you wear a scarf in winter, speech patterns...people make fun of people for every reason imaginable, and no reason at all. And those who do so usually aren't even social outcasts.
Comment: @enthdegree - There's cruel, insensitive bullying – unacceptable in a professional environment – but there's also the ability to accept things as they are and maintain a sense of humor about them, rather than attempt to mask something in embarrassed shame. I think that's the gist here. My daughter – all five feet zero inches of her – has learned to laugh at short jokes. Also, there's a difference between me being mocked for my epilepsy, and someone making a good-natured quip about it; it's healthy for me to not automatically regard the latter as the former. I think that's what's being said.
Comment: @enthdegree: regardless of how many people _actually_ make fun of people who stutter (and they definitely exist), stuttering is largely caused by the thoughts you're having about what people will think of the way you're "talking" right now. "Oh shit, I'm going to stutter, they'll think I'm ridiculous." It took me 25 years to almost get rid of my stuttering, but that path started at 15 when I told myself I just didn't care what people thought about it anymore. It's step 1.
Comment: "Just spit it out" is possibly the worst advice to give to someone with a stutter - all it does is make them even more conscious of the speech impediment. (Source: I stutter under stress.)  The thing that works for me is being able to pause, take a breath, and start again after collecting myself. A rush to "spit it out" only puts me in a worse situation.
Comment: @enthdegree - First I agree that it is a bully mechanism most of the time.  But there is no way around it.  A few weeks ago I saw a presentation by a chancellor, who is a very very attractive 40ish woman.  She was wearing a very professional suit/skirt.  I heard three women make comments regarding her skirt, earrings, whatever.   You don't think stuttering will get poked at?  Also I am still very good friends with Paul.  If you didn't make fun of his stuttering a bit (friendly poking around) he would surely think that you looked down on him about it.
Comment: @fluffy - maybe better said would be - eventually spit out what you are trying to say.  I stuttered up until college and I know that I quit saying some things that made me stutter or would stop mid sentence.
Comment: @RemcoGerlich I am not sure that is a scientifically accurate statement.  Stutters can start at the age of 2 or 3 and the underlying causes, as far as I know, are varied and not entirely understood.
Comment: @J.R. - Exactly.  Those who go through tough impediments while maintaining an good attitude are truly special.  It is very easy to be drawn to these people.  Isn't Stephen Hawking the benchmark for this?  Just 15-20 years ago he was a secret genius.  His willingness to "let go" has made him a global celebrity and really a person that has defined how to live.
Comment: Good post. But honestly, who makes fun of people who stutter? Calling people on any sort of real disability is a massive social pariah. I don't even remember the low-income bully thugs in elementary school doing this sort of thing.
Comment: how to make others not feel awkward..? especially when the stutterer is having low self-esteem.
Answer: People with a stutter can definitely have a career in academia. I know this because I've had a professor with a stammer.
From what I understand, a stutter can be amplified by stress. So if someone has serious anxiety about public speaking (giving lectures, presentations, etc.), it may not be a good idea to pursue an academic career. Of course, one could easily see the anxiety as the primary problem in this case, and the stutter as incidental. In general, if you have a stammer and think you could be a professor, then you probably can. You've had the stutter all your life, you know better than any of us how to handle different situations.
Don't worry too much about whether other people think you can do the work, either. What they think about your ability doesn't affect your actual ability. Furthermore, if anyone tries to interfere with your work or deny you a job because a speech disorder, they are probably violating worker protection laws.
Answer: This blog is the first one that I have found about pursuing an academic career having to stutter on The Internet. I was born with hypoacusia, and I was treated to recover almost all of the hearing capacity. Then, I have been stuttering since I was a kid. Now, I am doing the last year of my Ph.D. abroad and in English. In my native language, I have managed to control my stuttering by using synonyms to hard words, talking very slowly and using tag words linked to words that are hard to say to me without stuttering. Indeed, it has been a challenge to apply these techniques in English.
In all my years in academia (undergraduate, then in my Masters (working as a teaching graduate assistant) and finally in my Ph.D. years), I have to say that it is possible to carry on and survive academia with stuttering. Although I had had terrible presentations when my stuttering was so intense, that I couldn't finish explaining my point, I also had very good presentations where I could speak almost with total fluency. I have learned from these good and bad experiences, and I came out with a strategy to deal with the stuttering. Also for me, I tend to stutter when I am introducing myself to new people. Indeed, meeting new colleagues, presenting your work and networking are very common things to do in academia.
I have some tips on how to deal with situations when stuttering is more probable. Maybe these tips sound too obvious, but this has worked for me so far:
1) Indeed, by feeling that you have prepared your presentation by practising by yourself and even making a script help to boost your confidence and avoid the stuttering.
2) I find the first seconds of the talk the worst because automatically I feel that I will stutter. Therefore, I have found that the best way to overcome that is to find the words which I felt more comfortable to speak with and try to organise a starter sentence. For instance, I tend to start my sentences with tag words such as "OK" or "well". Although sometimes I had silly ways to start talking, this helped me to "break the ice" and no stutter from the beginning.  When I have applied this technique, most of the presentations had finished very well. This method gave me confidence from the start; like a boost.
3) Another strategy is trying to avoid the use of text as much as possible in the slides. Only using pictures or diagrams. I always felt so frustrated when I tried to say a word that is on the slide; this situation leads me to stutter for sure. Therefore, by using mostly graphs and diagrams, I was not feeling the pressure that I have words to say. Then, I can be open to improvising and use synonyms when reaching a word which I use to stutter with (I am aware that this technique of using synonyms is used widely by people who stutter. However it has been a challenge for me to apply this method in another language). I had the opportunity to master this technique when I was a teaching to undergraduates. Indeed, I felt so much confident that the stuttering was almost entirely gone. Moreover, the students were so happy with the way I explained using diagrams and animations.
4) Indeed, I have experienced an improvement in my speech when I modulate my breathing. I encourage to do this exercises a couple of hours before any presentation. Conscious breathing helps to relax. It is like tuning and adjusting the sound system of a concert.
5) If you have plenty of time, it is recommended to have a script for your presentation. By doing this, you can see which words are the most problematic to say. Then, it will help you to prepare alternative-more-relaxing-words to say.
In general, I have to say, my presentations in academia have been like a rollercoaster with ups and downs. The important thing is not to succumb or feel defeated when you have a bad presentation. Like every time, just learning from my mistakes and analysing why I was stuttering. I know it feels awful when you again stutter in a presentation. However, the key thing is to avoid feeling so bad and understanding and accepting that stuttering is part of your life. I think that in part when you are applying this technique of talking slowly and with some style, you are making your lectures or way to interact socially so unique that people will remember you more.
Please let me know if you have any comments. I will like to discuss with people having my same situation. So far, I have not met anyone experiencing this situation at a Ph.D. studies level. Finally, I have to say that I chose an academic path because I like to research and teach.
Comment: Welcome to the site and a great first contribution! I wanted to let you know that this is not a blog, but a Question and Answer site, so your first sentence sounds a bit awkward. Also, the last paragraph is a bit unusual since the site is not for discussions but for questions and answer. However, I would not like to edit it away, but you may want to add some email address to your profile so that interested people can contact you (and do not have to discuss here in the comment section).
Comment: Thanks for the reply. Sorry, I was so inspired that I didn't notice that! I forgot to include my email: email@example.com
Comment: Thumbs up for tips for stuttering in foreign language especially english. since english is the global language, most people look down on people who cant speak english fluently (even without the stuttering!). So the pressure is really heavy especially for non-native stutterer. I would like to ask, what if the person suffers stuttering in every sentence in the presentation every day?
Answer: If Jim Abbott can pitch with one arm, if Hector Picard can complete a triathlon, then you (if the question is about you) can certainly lecture with a stutter. Follow your dreams.
By the way, I work in academia alongside a physicist who is a very effective lecturer despite his stuttering. I've also known people who succeeded in academia despite their lisps, their heavy accents, their shyness, or their wheelchair – folks who were generally well-liked by students and had rightly earned the sincere respect of fellow faculty. Need I mention Stephen Hawking?
Lisps and limps, stammers and stutters, accents and hoarse voices; these are all things that will get noticed during the first day of class, but go largely unnoticed by the third or fourth week, especially when the lecturer has passion for the subject and is amiable in the delivery.
Answer: A person who stutters can definitely have an excellent career in academia.  I am a stutterer and have been a professor of business at a good university in Canada for over 30 years.  I did encounter some discrimination in both obtaining my Ph.D. and in securing an academic job.  For example, when I was working on my Masters degree I asked the Department head to write me a letter of recommendation to get into the doctoral program.  He refused, stating that he 'could not waste a valuable spot on someone who couldn't teach'.  He was wrong to do that, of course, as I teach just fine (albeit with some stuttering).  You should pursue the career that YOU want and not let others tell you what they think your limitations are.  The only limitations, I believe, are the ones we impose on ourselves.  Good luck!
Answer: Make it your advantage. The art of embracing things like that and instead glowing confidence can make one to be remembered and to be respected above normal.
Answer: Don Knuth, computer scientist No. 1, is somewhat stuttering. Not much, but he still struggles with his speech. Stephen Hawking cannot speak without a computer at all.  Said that, the absence of clear speech is not a stopper; you can make an excellent academic career.  You may have some trouble speaking publicly, but that's a different issue.
If stuttering bothers you personally, you might think about investing time and money into working with a speech therapist rather than into academia, which is a hard sports anyway. Your progress with the therapist may be small, especially if you are older, but it's worth it for your life. Not for academia.
Comment: Knuth and Hawking seem contrieved examples - it is possible that the questioner is not as good as a researcher as them.
Answer: You would at some points be held to a higher standards than others; however, if your research is good, you should be respected.


AsteriskNow Migration / Shared Extension Space

Question: I am testing the possibility of migrating from an old Avaya phone system to AsteriskNow.  The migration would cover several hundred phones--but spread out over several years.  (Management wants to move buildings to the new phone system one by one as cables get cut or time permits.)
Two other directive is that extensions must not change and they want a GUI that other admins (non-Linux geeks) can manage.
They currently use 9XXX for all extensions.
We linked the Avaya and Asterisk box via PRI card and they both are communicating.
From the Avaya side, if we move (for example) extension 9001 to Asterisk, we forward the call over the PRI to the AsteriskNow box and the SIP phone rings.
In AsteriskNow we have an outgoing rule '_9XXX' that routes all 4-digit extensions starting with 9 back to Avaya.
Here's the trouble.  Dialing 9001 (the extension moved over to AsteriskNow) causes the call to be routed out the PRI to the Avaya box, then the Avaya box routes the call back to Asterisk, and Asterisk routes it to the SIP phone.
As we get more and more users switched over, it will use up more and more channels over the PRI card.
Is there a way I can ask Asterisk to check it's local extensions first--then forward off to the Avaya system if it starts with '_9XXX'?  (I know how I can do it when editing the raw config files, I'm just looking for a way to do it in the GUI so other admins can manage it if necessary.)
As a last-ditch plan, I know I can specifically add '_9001' as an outgoing call rule and sent it directly to extension 9001--but I'd really hate to do that for several hundred phones
Answer: Turns out there's a checkbox when you are in advanced mode called 'shared dialplan' which can pass any non-matched extension to another system.


Can quantum computing contribute to the development of artificial intelligence?

Question: I am interested how quantum computing can contribute to the development of artificial intelligence, I did some searching, but could not find much. Does somebody have an idea (or speculations)?
Comment: [Here](https://quantumcomputing.stackexchange.com/q/2151/4153) is a list of technical resources on quantum machine learning; are you looking for answers more on the technical side or high-level nontechnical side? For example, less about how quantum ML works and more about how it might affect the field of ML.
Comment: see also [To what extent can quantum computers help to develop Artificial Intelligence?](https://ai.stackexchange.com/q/36/4314) over on ai.SE
Comment: @ahelwer Thank you for the list (which is a great starting point!), I am interested in the high-level nontechnical side
Answer: In my view, if artificial general intelligence (AGI) is ever 'solved', it likely won't be because of the development of a quantum AI algorithm. Rather, it will be because of a breakthrough in the training of existing classical algorithms.
That said, much like in the classical case (i.e. classical machine learning), research on quantum algorithms with plausible applications to some future AGI largely center on quantum machine learning (QML). QML research is still in its infancy relative to classical machine learning research and its practical benefits are only beginning to be understood. Here's a broad overview of some general themes that appear to be emerging:

We know that QML can provide algorithmic speedups. Much of the work in QML has been based on the quantum linear systems algorithm (QLSA, also known as HHL). This algorithm can be used to invert a covariance matrix, which is useful for the training of (for example) support vector machines and Gaussian process models. While somewhat controversial, the speedups of QML algorithms based on the HHL algorithm were originally thought to be superpolynomial (given some caveats, see this paper by Aaronson and another by Childs). Now, however, the speedups are generally believed to be polynomial (in many cases) due to the assumptions made in developing many QML algorithms and dequantization arguments (see here and here). For a nice overview, see this Quanta article. Also note that some of the caveats discussed in the links above have been addressed by refinements to the HHL algorithm. Also, it's notable that these specific algorithms often require quantum data as their input, which means they can't simply be added into a classical ML pipeline.

It's unclear to what extent quantum information enhances or limits model representations. When developing a machine learning model, one of the central goals is to learn a representation (e.g. the parameters of a neural network model) that enables us to make accurate predictions on unseen data drawn from a distribution we assume to be i.i.d. with the training data. An interesting question in this respect is whether using qubits to generate a learned representation offers any advantage over the standard (classical) representations currently being generated. Intuitively, quantum representations may have advantages for certain problems that inherently involve quantum effects, such as molecular simulation. Some recent work in this area indicates that certain QML algorithms may have improved trainability (i.e. fewer barren plateaus and narrow gorges), lower generalization error, and reduced sample complexity.

How should we be performing regularization in the QML context. It's been argued that some existing QML algorithms would massively overfit the data, severely limiting generalizability (for example, Peter Wittek notes the issue here while discussing quantum support vector machines). In classical machine learning, to ensure the ability of a model to generalize, we usually make use of some kind of regularization technique. I haven't yet seen any research around a QML approach to regularization (although variational quantum algorithms, discussed below, represent a glaring exception); perhaps someone else can comment on whether such approaches have been proposed for algorithms processing quantum data. A linking concept here may be the recent development of quantum kernel methods.

Limited complexity guarantees. Typically, we like our algorithms to offer some kind of guarantee around the worst-case behavior in terms of resource usage given some input size. Variational quantum algorithms, which are now central to the pursuit of practical quantum advantages in the near term, rarely provide these guarantees. While a lack of these guarantees doesn't preclude the possibility of a practical application in any way, it does mean that evidence that a classical approach couldn't do better is heterogenous, often informal, and highly problem specific.

I/O Another aspect is the input and output of the QML algorithm – are we inputting and outputting classical data like a traditional ML algorithm but doing quantum processing in the middle? Or rather is our input or output quantum? Or maybe they're both quantum? These details are hugely important to the realization of quantum advantages and, in particular, how to best input classical data into a QML algorithm is an area of great interest (and the input problem, in general, is not new).

There's certainly more that could be discussed relating to this question and, to be transparent, I am still very much learning this area. I hope more answers roll in but, until then, perhaps the information above can provide some context around what I would suggest the answer to your question is: We don't really know, yet.
Comment: On #3, I'm not sure if that that matters much to QML algorithms. The non-linearity, in many neural networks is only there for the *shape* of the function, and can be *heavily* approximated to the point where your activation function is actually a function of **8 bit** values.  You have **a lot** of leeway when it comes to these functions.
Comment: My understanding has progressed since I originally wrote; I'll post an update in the near future.
Comment: Yes, I suspected approximation would probably be sufficient, but thought it worth noting above. Along these lines, many of the activation functions widely used in contemporary image processing NNs (i.e. ReLU and its siblings) are linear.


Why there are no terrestrial planets with a subsurface ocean?

Question: Subsurface oceans in satellites are pretty common: Europa, Enceladus, Ganymede, Callisto, maybe Pluto... This is due to tidal heating of their host planet, Jupiter and Saturn, which heats up the inner ice of those satellites. However, planets don't exhibit this inner ice layer, so they don't usually have subsurface oceans (except Pluto or Ceres, if you can call them "planets"). Why is that? Only small bodies like satellites present this inner layer of ice? Is there any Earth-type exoplanets that exhibit this inner layer of ice that could potentially melt down to liquid water? And if there is, why some cold planets have inner ice layers and others don't?
Comment: Earth apparently has a subsurface reservoir of water greater than all the oceans combined; https://www.newscientist.com/article/dn25723-massive-ocean-discovered-towards-earths-core/
Comment: Europa, Ganymede, et al. don't really have "inner ice layers"; they have _outer_ ice layers. It's the inner part of this outer layer that is liquid.
Answer: Some hypothesize that the Earth did have a subsurface ocean during the Cryogenian period, which lasted from 720 to 635 million years ago. The Cryogenian saw the two greatest known ice ages in the Earth's history, the Sturtian and Marinoan glaciations. There is some evidence that the Earth was completely covered with ice and snow during those glaciations. (There is also some evidence that it was not.)
Whether even older periods in the Earth's history also succumbed to snowball Earth episodes is even more debatable. The evidence has been wiped out by a billion plus years of tectonic activity. That even older periods of the Earth's history than the Cryogenian did suffer snowball Earth episodes does however make sense.
The Sun is considerably more luminous now than it was shortly after the Earth first formed. Once the Earth cooled from its formation (and that appears to have happened fairly quickly, in a geological sense of "quickly"), that faint young Sun should have resulted in a cool Earth. That the young Earth had periods where it obviously wasn't covered with ice and snow from pole to pole is the faint young Sun paradox. The apparent paradox is almost uniformly explained away via greenhouse gases. But which ones?
That said, once plants started converting carbon dioxide into oxygen, and once the oxygen stopped combining with iron to form most of the world's iron ore deposits, the greenhouse effect that kept the young Earth from freezing over should have dropped significantly. There are some signs that this happened, some that it didn't. Puzzling out what happened well before the Cambrian has always been problematic because rocks that old are hard to find.
Comment: There may also have been [a longer, even more ancient](https://en.wikipedia.org/wiki/Huronian_glaciation#Causes_and_effects) example of that.
Answer: The terrestrial planets are Mercury, Venus, Earth and Mars.  Mercury and Venus are too hot for liquid water to exist at any level, Mars has lost nearly all its water and Earth has a surface ocean, not a subsurface one. The inner planets lost most of their volatiles (including water) as they formed, the water on Earth was provided by later icy asteroid impacts.
So none of the terrestrial planets have a sub-surface ocean.  The other planets are gas and ice giants.  Uranus and Neptune likely have liquid layers surrounding their cores, composed of water, ammonia and other "ices"
To get a subsurface ocean you need a planet that is beyond the frost line (the distance from the sun at which ice is stable in space) and in our solar system the planets beyond the frost line are either dwarfs or giants.
In a sense, the Earth does have a subsurface ocean, only it isn't a water ocean, it is an ocean of molten iron. The outer core of the Earth is highly fluid; it's no more viscous than water.
Among exoplanets, there are several candidate ice planets. Wikipedia lists  OGLE-2005-BLG-390Lb, OGLE-2013-BLG-0341L b and MOA-2007-BLG-192Lb.  (The principle way of discovering small planets that orbit far from their host star is by microlensing events, hence many of the candidate planets were found by the  Optical Gravitational Lens Experiment, or OGLE)
Comment: So what you say is, the formation of planets/satellites with inner ice layers is posible behind the snow line? Because Mars actually didn't lose all the subsurface ice, actually it's believed that there is some subterranean ice, not a layer. Maybe the reason that Mars doesn't have an ice layer is because when it was formed, the ice couldn't sustain its solid form...
Comment: Yes, there is a little subsurface water on Mars,  but Mars is not cold enough to have a thick ice shroud, like Ceres, and not big enough to hold onto what water it had after its formation, like Earth. exoplanets like OGLE-2005-BLG-390Lb, are distanct enough from their stars that they must be icy.
Comment: @Carlos There's some info about the amount of water / ice on Mars in my answer to this question:  https://astronomy.stackexchange.com/q/32484/16685
Comment: " The inner planets lost most of their volatiles (including water) as they formed" You failed to specify _liquid_ water, _free_ ammonia/ _excess_ ammonium, etc. Earth has- and thus, had- more water in the form of hydrogarnet (H4O4), ringwoodite solution, explicit hydrates (amphiboles, serpenti-X-es, the list is long), plus lesser "brine film" (monolayers + bilayers). If the core is included (not called too deep and non-participatory) then the door is open to iron hydrides, maybe sulfur and silicon hydrides, etc. Subsurface water is, at min, ~ all visible oceans, maybe an order of mag more.
Comment: @caInstrument all true, but also irrelevant, since hydrogarnet etc isn't a "subsurface ocean"   That means a liquid layer of water.
Answer: There are no terrestrial planets with subsurface oceans because of differentiation.  Denser materials move toward the center of the body.  Iron is denser than rock which is denser than water which is denser than ice.  The icy surface of these moons and dwarf planets is essentially floating on water which is floating on rock.  You can actually see this on Earth.  We have a partial subsurface ocean at the poles where water ice floats on top of the ocean.
Answer: We may regard Earth's ocean as a subsurface ocean that has melted through. Temperatures on Earth's surface are too warm to maintain the global ice covering which, on the outer-planet moons, renders oceans subterranean.
A key property Earth's ocean shares with its subterranean outer-moon counterparts is sunlight is essentially unable to penetrate through to the bottom. Yet life is based down there, drawing its energy from the thermochemical processes at high-temperature vents. Astrophysicists and astrobiologists consider this a model for possible subterranean life on the outer-planet moons.
Earth also has water beneath the ocean floors, distributed in the mantle. While much of this internal water is chemically combined into hydroxylated minerals, the finding of Ice VII inclusions in diamonds [1] indicates the presence of molecular $\text{H}_2\text{O}$. Within the mantle this water would be at temperatures and pressures much too high for any ordinary liquid or gas phase; it would be a supercritical and maybe partly ionic[2] fluid.
Water may also exist as a significant component beneath the surface on Mars, but with (currently) no surface ocean and no extensive ice layer it shows no evidence of the water being aggregated into any liquid subterranean ocean. Nonetheless, if any underground water on Mars is liquid (which may be the case beneath the Martian south pole[3]) it may harbor life as well as the deep or subterranean oceans on Earth and the outer moons.
References

Tschauner, Oliver & Huang, Shichun & Greenberg, Eran & Prakapenka, V. & Rossman, George & Shen, Andy & Zhang, D. & Newville, Matthew & Lanzirotti, A. & Tait, Kimberly. (2018). "Ice-VII inclusions in diamonds: Evidence for aqueous fluid in Earth's deep mantle". Science 359, 1136-1139. 10.1126/science.aao3030.

Viktor Rozsa, Ding Pan, Federico Giberti, and Giulia Galli (2018). "Ab initio spectroscopy and ionic conductivity of water under Earth mantle
Proceedings of the National Academy od Sciences 115(27), 6952-6957.
https://doi.org/10.1073/pnas.1800123115

Arnold, N.S., Butcher, F.E.G., Conway, S.J. et al. (2022). "Surface topographic impact of subglacial water beneath the south polar ice cap of Mars". Nat Astron 6, 1256–1262. https://doi.org/10.1038/s41550-022-01782-0
Answer: As far as I know satellite data from Mars observers show significant amounts of ice blow the south pole and pointers to a similar though smaller amount at the northern pole of Mars.
This is not surprising - Mars' plate tectonics stopped approx 1.2 to 1.5 billion years ago after the planets core cooled down enough. Mars' smaller mass and volume didn't provide enough "insulation" to keep the core hot. Thus the magnetic field of Mars pretty much vanished - and was the only protection for the atmosphere against the solar wind.
So Mars' atmosphere is now only as thin as earths atmosphere in 48 km height - and easily allows evaporation of surface water, so the only remaining water is sub surface OR in some shadowed craters
Comment: Mars' mantle water is comparable to Earth mantle water. Martian meteorites that aren't sedimentary, and considered representative of its interior, contain as much water as Earth samples considered representative of our upper mantle…
Comment: …and if you're only considering _free_ water (bulk deposits, in any phase), hence your "only remaining water" qualification, then the polar cap status is rather ambiguous. The perihelion pole is warmer, the aphelion pole colder, and bulk water ice is viable on the surface at one.
Comment: @caInstrument interesting fact about Mars, can we see a reference? Also are there any _diamonds_ on Mars? Those on Earth show evidence of free water in the mantle when they include (cooled and condensed) Ice VII.
Answer: It depends what you mean by ocean. Earth arguably has a subsurface ocean of liquid iron, usually called the "outer core".
Comment: When I say "ocean", I mean water or  liquid ammonia
Comment: @CarlosVázquezMonzón I think we knew it, but it is an interesting point, if we are not humanocentric.
Answer: Basically, ocean indicates water. Those bodies of which you spoke have oceans which are completely covered by ice, the interiors are warm enough because of tidal heating, but, the surface loses heat to space freezing the surface water. Mercury through Mars are too warm for that to occur. Antarctica has a subsurface lake, it's warm enough below the ice cap, so, that's sort of a subsurface water body. As spoken of in some of the above posts, one or more ice ages on the Earth was so cold, we had a 'snowball' Earth, which would be like a subsurface ocean below that thin ice cover. Then, fortunately for us, it melted.


Dell Dimension l866r

Question: I'm using an old Dell Dimension l866R desktop w/a floppy drive detected error upon boot. There is a floppy drive in the case but it's not connected to power supply nor motherboard. None of the keys are allowing me to enter BIOS setup to disable floppy drive. Any ideas would be helpful.
Answer:
Try using another keyboard
If the new keyboard doesn't work, go from USB to PS2 (or vice versa)
If none of these work, your motherboard could have something wrong with it and the sockets for the keyboard could be bad.

I noticed that with the Dell Dimension l866R, it only accepts the DEL key to get into BIOS. Give that a shot and comment back to tell me if anything worked.
Good Luck-
Answer: I found this for you, no need to find out the wheel twice :)
Clear the BIOS by doing this:Disconnect the power cable from the back of the computer. Open the side cover and carefully take out the cmos battery (looks like a silvery button). Keep it out for about 15 minutes. Reinstall and reboot. You will probably get a checksome error or some other message. If you do, enter BIOS and set time and date, save the new values and let the computer boot. Most desktops will boot into BIOS by clicking Delete or F2 keys immediately after switching on. There are computers in which other keys have to be used to enter BIOS (Setup). You can find the correct key when looking at the screen right after pressing the start button. If you don't, press the Pause/Break key immediately after startup to freeze the first screen. Now you should be able to see what keys tp press

Dell Dimension l866r


NXT motors spin when in air but stop on ground

Question: I have a car that I made with 2 motors in the back and one motor in the front. The motors spin fine in the air but when I put it on the ground to test my program the motors stop. The robot itself isn't very heavy so I don't think that is the issue.
Comment: Did you try what Phantom_IV suggested? I bet either the gear ratio between the front & back motors are different (which would cause the gear binding that Phantom_IV mentions) or else your batteries might just be too weak to drive the motors? Try disconnecting the front motor from the wheels, so the front wheels free-wheel to test if different gear ratios (wheels spinning at different rates) is causing binding.
Comment: I just noticed you have some sort of sensor in the front facing down; is that an optical sensor? Does your program turn the wheel motors off if it detects something? Try pointing the optical sensor off to the side & see if the motors start driving the car then.
Comment: It  is a color sensor for a line follower I am trying to make.
Comment: How can your car steer to follow the line? Is that what the front motor does? Or did you plan on the rear motors turning in opposite directions to steer it? To troubleshoot, did you try holding the car in the air, but with the color sensor pointing at your desk at the same height from it as shown in the picture? If you do that, do the rear wheels stop? If so, then it's your program that's making them stop. You'll have to troubleshoot your program.
Answer: NXT and EV3 motors don't slip unless set to coasting. This means that any external means to speed up or slow down the motor will be counteracted by the motor control. I believe basically one or more of your motors is acting as a brake for the others because the controllers believe that they should act that way to obtain the desired speeds you programmed them.
Even if all things are equal (desired motor speed, direction and wheel diameter), other minor variations within the motors can cause variations in the total speed that are counterproductive...
I once created a sumo bot having three motors, the intention being two motors for tank steering and an additional motor to provide extra power. I think this is similar as to what you are trying to achieve. My solution was to combine the motor speeds with differentials (as present in several technic vehicle sets)...
Answer: Can you post a picture of your car? Is it possible that the gearing is different, or wheel size is different, between the front & back? Maybe that would cause the gearing to bind up. Maybe try letting the front wheel free-spin (no motor) to see if the rear wheels will propel the car by themselves. If that works, switch it around, and let the rear wheels free-spin and see if the front motor can propel the car on its own. If so, note the speed of the car with the rear wheels motorized, and compare it to the speed of the car with the front wheel motorized. If it's different, then gear binding might be the issue.
Answer: Sounds/looks like a software issue.  My first guess was that the program is jumping straight into a line following algorithm and that program is stopping as soon as it detects the table top.  But, that would be fairly easy to test by approaching the table from the edge of the table, so the light sensor would stop the motors before the back wheels got close to the table.
Second guess.  The line following algorithm starts up in a mode that runs the motors at a low power setting (less than 5), which works when suspended in air, but it not enough power to turn the wheels when on the table because there is some resistance (either the front wheels or ?).  The line following is waiting for some rotation distance before moving to the next step and it waits forever.
Probably best to copy/paste sections of the program.  Throw out half until something works.
Of course, a screenshot of the program would help.


Is it possible to browse/search uploaded images?

Question: Is it possible to search uploaded images, for example type 'pie chart' and see the images connected to those posts?
Comment: If you're willing to do ~100 at a time you can use the StackExchange API (see [this](https://api.stackexchange.com/docs/answers) and use `filter=withbody`). Then you can pull out image tags. You can also do that for a specific user with [users/{ids}/answers](https://api.stackexchange.com/docs/answers-on-users). I have a service connection lying around on the site that might help with this too. You can also use [this .mx dump of answer metadata](https://www.wolframcloud.com/objects/b3m2a1.datasets/stack_exchange_data/answers/mmaAnswers.mx) as a starting point for searches.
Answer: Your best bet is to use Google I guess. Try to search like this
<code>pie chart site:https://mathematica.stackexchange.com/
</code>
Comment: Yes, that only shows a small subset.
Answer: AFAIK, halirutan has provided the most effective way to search for image using Google.
For SE's own tools, no, it's not really possible since images are stored just as that, image files. There's no metadata that describes if an image is a pie chart or anything else.
If users properly describe the alternative text on image markdown as "pie chart", e.g.
<code>![example of pie chart](https://i.stack.imgur.com/i0ey1.jpg)
</code>
then it's possible to search for that using SEDE (as of writing, there's none). However, SEDE is updated each week.


Plank to behave like Mac OS dock

Question: Is there a way to make the plank behave like the Mac OS dock. What i mean by this is that when the active window is not maximized or not in full-screen mode, then the dock should act as if the hide dock behavior is disabled, But if the active window is maximized or in full-screen mode then the hide dock behavior activates. I don't want to use the Auto-hide or InteliHide behavior because this causes some apps to open and overlap the dock which its in a normal state (Not maximized).
Comment: In case you are wondering where Window Dodge is: Ctrl+Right click on the dock > Preferences > Behaviour > Window Dodge. Default is set to 'Dodge maximized window'. Let us know if this is the desired behaviour.
Comment: Hide when: Focused window is maximized. Isn't that what you want? You have it in settings.
Comment: We do, but what that enables is that when you open a window, it can overlap the dock. I don't like it when a window is opened behind the dock, i then have to drag it above the dock myself.
Comment: Try Window Dodge setting. That's what I use and it works like it does on Mac
Answer: I'm not familiar with how macOS's dock behaves, but it sounds like the behavior you're describing is:

By default, the dock is shown
When no apps are maximized/fullscreened, windows don't ever automatically cover the dock (technically, the dock would not hide and would set struts, behaving like the hide mode is just turned off)
When a window is maximized, hide the dock

To me this sounds like a relatively small (and probably good) modification to the existing "dodge maximized window" behavior, and is probably best suited for a bug filed against Plank: https://bugs.launchpad.net/plank

Plank to behave like Mac OS dock


Vulnerability Scanner, nmap vs Nessus

Question: I need a good vulnerability auditing tool for Ubuntu so I decided to try nmap I also recalled that there was a product that can do this kind of work called Nessus it is no longer available in the repository and the packages for Ubuntu  at its site http://nessus.org/nessus/ are old, I suppose that the latest one may work on maverick though, does anyone have any experience using nessus? How does it compare to nmap?
Answer: As far as I'm aware, Nessus is no longer free. You should take a look at OpenVAS, which is a Nessus alternative (and has even better coverage), instead.
OpenVAS (Nessus alternative) and Nmap are very much different. You can use OpenVas to find vulnerabilities without knowing how to look for them as OpenVAS tries out numerous attacks collected from various sources, whereas you do need to know what you are doing, where to look for, with Nmap.
Answer: Nmap is faster, Nessus is more complete. The repositories of BackTrack have the lastest nessus and Nmap.
Answer: nmap is not a vulnerability scanner, it's  network services scanner, it only detects available network services, it does not scan them for vulnerabilities.
Nikto (from package nikto) is a good web server vulnerabilities scanner.
Comment: Thanks for your suggestion, yes you are correct about nmap not being a VS, it can be used in a limited way of such with scripts though.
Answer: You can still get Nessus for Linux. You need to download it direct from http://nessus.org/nessus/
Please note that there are differences between the pay for version and the free version. See here -> http://nessus.org/documentation/index.php?doc=faq#anchor66
Thanks
Chris
Comment: Also as already specified. NMAP is not a vulnerability scanner. It is a network scanner.
Comment: Technically, you are correct it is not a vulnerability scanner by itself, just a part of your security toolset, If you use scripts with it such as Nmap NSE Vulscan here: http://www.computec.ch/mruef/?s=software&l=e some VS can be done.
Answer: Nessus is available in a Free version (non-commercial use only).
OpenVAS the fork of Nessus is Open Source and continues to be developed (http://www.openvas.org).
NexPose is a vulnerability scanner from Rapid7, community version can scan up to 32 IP's for Free.
Nmap with NSE can perform vulnerability checks (as mentioned above).
A comparison was done recently between the different scanners - http://hackertarget.com/nessus-openvas-nexpose-vs-metasploitable/

Vulnerability Scanner, nmap vs Nessus


wearing necklaces that have verses from the Quran on them a sin?

Question: I don't understand how this is a form of Shirk?
I'm not Questioning Allah but no body has given me anything from the Quran that says we cannot wear necklaces with Quranic verses in them can somebody please explain how this would be shirk???
I mean it is Allahs words in the necklace to begin with?
Please don't be rude in your answers I'm genuinely unsure about this and would like to know more about this topic
Comment: So called (fake) sheikhs give people amulets which contain Quranic verses to 'protect them' with names of Shaytan and is therefore shirk.
Comment: What if one was to make the amulet he selected?
Comment: Please provide links to support your question. Which fatwas say what types of necklaces with verses of the Qur'an are shirk? Without reading the fatwas, this will be a matter of speculation.
Answer: There is no clear cut on the issue of written verses of qur'an on objects of daily use. But there's a consensus that once these verse would be misused or misplaced it is at least makrooh (frowned upon).
For example writing Qur'an verses on walls, clothes, food is makrooh ...  but it is permitted to destroy a wall with such verses on it or wear clothes where there are written on this based on a statement in Zakaria al-Ansari's book asna al-Matalib his commentary on the fiqh book rawd at-Tulaab أسنى المطالب في شرح روض الطالب which was quoted in this Arabic fatwa asking whether it is permissible to buy or sell clothes on which qur'an verses or the name(s) of Allah are printed on. This is basically there considered as permitted unless these clothes are used in a disrespectful way for the written text.
So basically all scholars agree that once you misuse such clothes or a neckless by for example entering a toilet wearing them it becomes at least makrooh if not haram. This is also the opinion presented in this Arabic fatwa on islamweb #51490. The opinion is based on the fact that the Prophet had a ring on which was written "Muhammad Rasull Allah" (Sahih al-Bukhari and sahih Muslim). And he used to take it off when entering the "toilet":

"When the Messenger of Allah (ﷺ) entered the area in which he would relieve himself, he would remove the ring." (Jami' at-Tirmdihi, sunan abi Dawod, sunan ibn Majah, sunan an-Nasa'i)

See also this fatwa on islamqa #68805 allowing printing or writing the name of Allah on rings.
So far shirk is excluded.
The issue of shirk only arise if you wear such a verse believing it may protect you from any bad or as a talisman or amulet. As shirk is related to what you believe an object a being or deity except Allah may do for you.

I heard Allah's Messenger (ﷺ) saying, "The reward of deeds depends upon the intentions and every person will get the reward according to what he has intended. So whoever emigrated for worldly benefits or for a woman to marry, his emigration was for what he emigrated for (Sahih al-Bukhari and other ahadith collections)

This fatwa on islamqa #91370 seems to declare all these things as haram for two major reasons:

disrespect
imitation of disbelievers.

According to that one is sinning when selling it, when buying it and when wearing it.
This fatwa also includes two ahadith from Musnad Ahmad saying which seem to be used in the context of wearing these verses such as if wearing an amulet, which indeed is a matter of shirk:

Ahmad (17458) narrated from 'Uqbah ibn 'Aamir al-Juhani (may Allaah be pleased with him) that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: "Whoever wears an amulet has associated something with Allaah (shirk)." Classed as saheeh by al-Albaani in Saheeh al-Jaami'.
Ahmad also narrated (17440) that 'Uqbah ibn 'Aamir (may Allaah be pleased with him) said: I heard the Messenger of Allaah (peace and blessings of Allaah be upon him) say: "Whoever wears an amulet, may Allaah not fulfil his need, and whoever wears a sea-shell, may Allaah not give him peace." Classed as hasan by Shu'ayb al-Arna'oot in Tahqeeq al-Musnad.

Finally note that scholars like al-Qurtobi in his tafsir discussed the matter on writing on ornaments or rings while commenting or interpreting verse (16:14):

And it is He who subjected the sea for you to eat from it tender meat and to extract from it ornaments which you wear. And you see the ships plowing through it, and [He subjected it] that you may seek of His bounty; and perhaps you will be grateful.
Answer: If it is not in the Qur'an, it is not shirk.
يَا أَيُّهَا الَّذِينَ آمَنُوا لَا تُحَرِّمُوا طَيِّبَاتِ مَا أَحَلَّ اللَّهُ لَكُمْ وَلَا تَعْتَدُوا ۚ إِنَّ اللَّهَ لَا يُحِبُّ الْمُعْتَدِينَ - 5:87
'"O you who have believed, do not prohibit the good things which Allah has made lawful to you and do not transgress. Indeed, Allah does not like transgressors.""
وَلَا تَقُولُوا لِمَا تَصِفُ أَلْسِنَتُكُمُ الْكَذِبَ هَٰذَا حَلَالٌ وَهَٰذَا حَرَامٌ لِّتَفْتَرُوا عَلَى اللَّهِ الْكَذِبَ ۚ إِنَّ الَّذِينَ يَفْتَرُونَ عَلَى اللَّهِ الْكَذِبَ لَا يُفْلِحُونَ - 16:116
"And do not say about what your tongues assert of untruth, "This is lawful and this is unlawful," to invent falsehood about Allah . Indeed, those who invent falsehood about Allah will not succeed."
Don't let the Human opinion influence you. I have one myself with Ayat  Al-kursi on it and I absolutely love wearing it. I feel very protected when I have it on.
Hope this helps
Answer: Assalam O Alaikum Brother!
(May Allah (SWT) have mercy on all of us)
I'm in distress time and is seeking refuge from Allah (SWT). He is the mighty and knows all.
Sorry but this is not an answer but I'm also looking for the answer. May Allah (SWT) guide us in right path.
I searched the internet and almost 80% on my research lead to that it is haram. But I'm confused how it is haram if we keep a Quranic verse in a form on an amulet.
I'm a human being and at least have this much common sense to understand that wearing stones, bones, shells and believing on them is shirk. But if we use a Quranic verse and still believe that will help us then I don't think my intention will be wrong?
I upvote the two answers above me because my heart says it seems right.
also wanted to share this article which has some reference regarding this question.
Islamic Beliefs & Teachings
Answer: Assalaam Alaiqum wa Rehmat Allah.
In my personal opinion, it is all dependent upon one's intention.  Having an intention that wearing such and such will protect us, would ultimately bring us to a compromised state.  That itself is a sign of weaker faith because protector is One and Only Allah Almighty. Nothing can harm us except by his permission, Remember this very base factor and it shall solve your basic concern and unfound fears. Shetan gives fears, it is True faith which provides hope and good tidings.
Everything happens by permission of Allah.
 قُل لَّن يُصِيبَنَآ إِلَّا مَا كَتَبَ ٱللَّهُ لَنَا هُوَ مَوْلَىٰنَا ۚ وَعَلَى ٱللَّهِ فَلْيَتَوَكَّلِ ٱلْمُؤْمِنُونَ
Al tauba 51...
Remember nothing can befalls upon us except that which is written for us. That which is meant to happen, will happen even if we wear Entire Qur'an upon us or even if we quarantine ourselves in a closed glass cube. Period!
Now on an another note, if we just wear it because it is a better choice to wear it rather than some worldly oriented sculpted pattern, it will remain to be the better chooce.
However, the next responsibility comes upon us would then be to ensure that no disrespect happens to it's sacredness.  Rest Assured Allah knows best. May Allah keep us guided to straight path Aameen. بألف الصلاة والسلام على نبينا محمد صلى الله عليه وسلم وعلى آله وأصحابه أجمعين
Answer: I had a SILVER PLATED CHAIN WITH ALLAHS NAME. THE REASON I WEAR IT? CAUSE IT REMINDS ME THAT ALLAH IS WITH ME AND WATCHING OVER ME. AND TO BE WELL AWARE OF MY ACTIONS,TO THINK BEFORE ACTING. ITS JUST LIKE HAVING A QURAN TO REMEMBER AND READ. JUST LIKE WE HAVE THE AHDEN CALLING ON ARE CELLPHONES TO BE REMINDED of the salat so dont you want to BE aware of the most high so carry ALLAH'S name and attribute at heart with good intentions whenever we leave we dont go back until he brightens our hearts remember that. So remember him in anyway but with a open heart.
Comment: Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer).


Blind Eye Pro - What Qualifies?

Question: I was reading the description of the blind eye pro perk in call of duty modern warfare 3 perk.  It says to destroy someone's streak item.  Does that mean things such as destroying crates, or does that include shooting down spy planes, choppers, etc?
Answer: Anything that's a killstreak reward counts, so things like choppers, UAVs, SAM turrets, sentry guns, etc.  If you can destroy it, and the enemy got it because of a killstreak, it counts.
I don't think you can destroy enemy care packages, so that's probably not something that counts towards this.  I believe that shooting down the care package delivery chopper counts, however.
Answer: When you destroy a number of enemy killstreaks being used while having Blind Eye equipped, that is when you unlock Blind Eye Pro. This is my Tier One Perk that I use because of it's usefulness of keeping you safe and giving you extra firepower against enemy killstreaks at the same time except for the ones that can be manually controlled, which you can still die from even with Blind Eye Pro, if for example you have Blind Eye Pro equipped and an enemy Reaper is in the air, it can still target you and kill you, it's just harder to spot you because you have no red square around your player character in the enemy killstreak's view.

Blind Eye Pro - What Qualifies?


Why is Neo the only one who does not use leather clothes in The Matrix movies?

Question: All the other main characters; Morpheus, Trinity and Niobe, persistently wear leather or PVC outfits (including jackets and pants) when they're in the Matrix but Neo doesn't.
Is there a special reason for this?
Comment: Out of universe, he sure looks like a jesuit; http://www.bibliotecapleyades.net/imagenes_sociopol/mediacontrol66_23.jpg
Comment: For the record, he wears leather boots, a leather belt and carries a leather phone case...
Comment: yeah, I know..but his outfit is different to the others, I think is for settle that he is the one and is different,
Answer: From what I've read, there really is no deeper meaning other than that the outfits were dictated by the need to create contrasts between the major characters and the need to craft outfits that would be suitable for the various fight sequences.
This interview with Kym Barrett ("Costume Designer" for The Matrix 1, 2 and 3) indicates that the amount of input from the Directors was actually quite minimal. Simply put, you can't do kung-fu in tight leather pants.

KYM: "They always say, and they've never deviated from this, "We want it to be dark, we want it to be high contrast, we want Trinity to
  be like an oil slick." They give me simple sentences and let me go
  away and come up with stuff, then we talk about it and it just grows.
  After that we make [the garment], tweak it, and it grows into things.
  Larry and Andy are great with allowing all of us (I think Owen
  [Paterson, Production Designer] would agree), they give you a little
  seed and then they let you expand it. Sometimes they think my ideas
  are ludicrous and they'll roll around the floor laughing, then they'll
  come back and say there was something there, even though it was a
  ridiculous idea. It's a good way to work; it's a very challenging and
  rewarding way to work
On one hand Larry and Andy are very broad, then on the other hand
  they're very detail oriented, so they work well seeing a body and
  seeing how the light hits the body. The way the shape of the garment
  moves in the air is really important to them, and you can't show those
  kind of things on a drawing. So, more often than not, they like to see
  a prototype of something, rather than just a drawing."

And this interview with Gloria Bava ("Costume Cutter" for the Matrix 1, 2 and 3) shows that they wanted to clothe Neo in a non-shiny fabric to ensure an immediate visual contrast with Trinity and Morpheus. You should be able to tell their characters apart instantly.

GLORIA: Neo's fabric was sourced around Sydney, and they found it in Sydney at a tailoring supply place. It had to be the right weight,
  it had to be the right shade of black, it had to have a matte-ness
  about it, not shiny in any way, and it had to have the right sort of
  loose weave. It was more like a twill weave, which was very good to
  work with, and it wasn't a real black black, it was bordering on a
  charcoal to black shade. When they found the fabric they bought lots
  of it, and I think ended up making about four of those coats.
Answer: Neo's appearance in the Matrix notably shifts from the first movie to the rest of the trilogy. Whereas he takes a utilitarian approach in the first, coated in weaponry and tools, Reloaded and Revolutions show him in a coat which is very visually similar to the cassock - the garb of a priest.
This reflects the nature of his role as viewed by those who believe in the Prophecy; in their eyes, Neo is similar to a religious figure. The Prophecy as a religion is expressed throughout the films, perhaps most pointedly as a major point of contention between Cmdr. Lock(Deadbolt) and Morpheus:

Commander Lock: Dammit, Morpheus. Not everyone believes
  what you believe.
Morpheus: My beliefs do not require them to.

Apart from the practicality of engaging in MMA-style fighting with leather clothes on (which "shouldn't matter" in the Matrix, but sadly our actors are subject to the physics of real life), it also gives his apparel a 'cape-like' effect to embellish his powers of flight. As it would happen, cassocks are not made of leather, they tend to be made of cotton and/or polyester.
At the end of the day it is another bit of real-world religious imagery that is injected into the movies to lend credence to Neo's status as the savior of the human race.
Comment: Because cassocks aren't made of leather. They're made of cotton, or polyester.
Comment: That needs to be in the answer then...
Comment: But why no leather?
Comment: I thought it was a sherwani.
Answer: But he did have a leather jacket. I think that the clothing is more down to the individuals style as opposed to some rule that they have to wear leather. Because it'd be pretty easy for the machines to make a day where no one wears leather in the matrix thus the people who are free would stand out like sore thumbs.


Why was my appearance vs health answer deleted?

Question: I've improved my previous (deleted) answer by including fewer pics and more text & links, and as it's "impossible" to undelete that because it was deleted by a moderator, I've answered anew.
I'm still wondering why my first answer was deleted, though, as the questioner is not curious about apparent health, but actual health, a connection that I clearly showed (too much?).
Answer: My impression was that you posted the images for shock value, not only to answer the question. That was what caused the immediate deletion. I also think that you're missing the point of the question, it is not about diseases that show visible symptoms that affect beauty, but about a more general correlation between beauty and health. So you answer also didn't actually answer the question.
I'm still not convinced that your now changed answer actually addresses the question that is asked, but I'll leave it to the community to deal with it. I've undeleted your old answer and deleted the duplicate one. In general, please flag for undeletion instead of duplicating your deleted answers.
Comment: I chose the most illustrative yet tasteful images I could find, and even commented that the girl in the first image was cute aside from the scabs. (The hip hop artist and DJ, [Leon Botha](http://en.wikipedia.org/wiki/Leon_Botha), in the second image was even smiling.)
Thus I've clearly shown that disease (health flaw) can affect appearance (beauty). Appearance does not affect disease that much.

I tried to flag for undeletion, but then this site told me that undeletion was impossible for aforementioned reason. Please be more considerate and explain your actions in the future.


Does it make sense to make exam grading very transparent?

Question: Is it advisable (in terms of the benefit for the students and the work it causes) to make the grading completely transparent to students? I think for instance of publishing the sample solutions for the exam or the distribution of the grades given. Would those measures be suitable to convince the students that the grading is fair or would it rather make worse students feel treated in an unfair way and trigger many complaints? As far as I understand the University now normally lets the students only see their individual grades. Of course they will always compare themselves in smaller groups.
Comment: There was a similar question a little while ago, and one of the answer (by @BrianBorchers )correctly points out: *Don't release the rubric unless you're really willing to give credit according to the rubric even if a paper has obvious flaws in areas not covered by the rubric.*
(the answer is here http://academia.stackexchange.com/questions/30601/should-students-be-shown-the-grading-rubric/30603#comment67319_30603)
Comment: In the class I TA (programming), we don't have a tests, instead the students are given practical assignment. To promote the transparency, we publish "error cheat sheet". At the start every student has full score, I then go through his code and for every violation in cheat sheet subtract the relevant points. It works well, but I undesrtand it's rather  specific.
Answer: Transparency is great, when you can do it.  Many of my large undergraduate classes would show a score histogram for every major quiz or exam, and some would explicitly give the grading rubric.  This was generally very much appreciated by the students for exactly the reasons you give: better understanding of how they stand and why they got the scores they got, letting them judge fairness and know when to reasonably object (which sometimes happened).
From the TA side, my experience was that transparency actually decreased my work, because it meant that I didn't need to deal with many spurious complaints, and that many of the complaints could be resolved directly through reference to the rubric.
Comment: When _can't_ you do it?
Comment: @JeffE I can't think of a time, but one of the things I've been learning on this site is that there are a lot of institutions that behave in ways that seem awfully odd to me...
Comment: @JeffE: When grading essay answers (sometimes).
Answer: I always made my grading as transparent as possible. It makes it fairer for the students and if they complain and gather points where they should not get them, it helps me improve the grading in the next exam.
From my point of view, tutors/teachers/examiners that do not make their grading transparent are not professional and seem to be weak at grading, otherwise they would not fear to make their process transparent.


Login sound still plays despite disabling from administration login screen

Question: In maverick, I get the login sound when my computer starts up and I auto-login.
The happens despite the fact that I've turned off the "play login sound" on the administration > login screen dialog.
How can I turn off the login sound playing?
Answer: The login screen dialog dictates what happens when GDM (The login screen loads) The sound you're likely referring to is actually the GNOME Login Sound which can be disabled in the Startup Applications windows under
System > Preferences > Startup Applications
Answer: Maybe try Preferences > Startup Applications > Gnome Login Sound, and disabling it.
EDIT: I would also like to add that you change the sound to your whim: you could put any 10-second sound when Ubuntu starts up.


My Toilet Keeps Making Sounds Like It Is Filling Up Every 3 Minutes

Question: What is causing my toilets to kick on every other minute? It's not flushing - it sounds like the water is filling up. Does this make the electric bill higher?
Comment: Won't affect the electric bill. But it will affect the water bill.
Comment: It will if they are on a well.
Answer: Since you aren't seeing water all over the place, your flapper is leaking a small amount of water which is causing the float to drop to a level (apparently every 3 minutes) where it detects the water is low, so it fills the tank back up. If you aren't familiar with the mechanics of the float/flapper system in toilets, take the tank lid off and flush it a few times; it's pretty easy to see what it is doing. You might be able to slight adjust the flapper by just running your thumb around the part that seats or you might need to replace it (it's cheap and easy).
As far as electric bill, it won't make your electric bill higher if you live in the city since water is fed by gravity, but in the country where water is pumped from underground, it would. The bigger concern would be water cost if you are in the city.
Comment: My flapper went off center over the hole. I fixed the problem by adding a 1/4" piece of neoprene stopper, sliced halfway through with a razorblade on the right side of the flapper pivot. Flapper is now centered, and problem is gone 5 months now.
Answer: You probably have a leak on the flush flapper (or whatever mechanism lets the water into the bowl), it's slow enough to not notice, but when the float gets low, it has to refill the tank.


coNP certificate for Graph Isomorphism

Question: It is easy to see that graph isomorphism(GI) is in NP. It is a major open problem whether GI is in coNP. Are there any potential candidates of properties of graphs that can be used as coNP certificates of GI. Any conjectures that imply $GI \in coNP$ ? What are some implications of $GI \in coNP$ ?
Answer: If $GI$ is in $coNP$, then we would have the result: $GI$ is not $NP$-complete unless $NP=coNP=PH$.  (Currently known: $GI$ is not $NP$-complete unless $\Sigma_2 P = \Pi_2 P = PH$).
Since $GI$ is in $coAM$, obviously derandomizing $coAM$ (doi link) would put $GI \in coNP$, but I don't know of any candidate graph properties for putting $GI \in coNP$ otherwise. I look forward to more answers though!
Interestingly, in that paper they also show that Graph Non-Isomorphism has subexponential size proofs -- that is, $GI \in co NSUBEXP$ -- unless $PH = \Sigma_3 P$.  This is at least headed in the direction of showing conditionally that $GI \in coNP$.
Comment: There is another derandomization result for $AM \cap coAM$ by Gutfreund, Shaltiel and Ta-Shma (Uniform hardness vs. randomness for Arthur-Merlin games, in Computational Complexity 12(3-4):85-130, 2003) . This result works under uniform hardness assumptions (with the usual i.o. caveat).
Answer: How about the range (i.e. list, one entry per edge) of effective resistances?  The effective resistance of an edge is the probability that the edge is in a random spanning tree.  Effective resistances can be found using algorithms of Spielman and Teng, although I don't know how easy it is to actually implement (if one wanted to do experiments).
Suppose we have two strongly regular graphs, which have the same eigenvalues (and we know that eigenvalues do not necessarily distinguish between non-isomorphic graphs).  Then if the effective resistances (i.e. the lists, again) are the same, they can not be used to distinguish the graphs.  But why would two co-spectral graphs have the same distribution of their edges in random spanning trees?  Is there a known connection between the graph spectrum and the effective resistances of a graph?  i.e. knowning the graph spectrum, can we compute the effective resistances?
Answer: It could be interesting to point out that if GI is not in coNP then P ≠ NP.
1)If GI is not in coNp then GI ≠ NGI
2)If GI ≠ NGI then GI ≠ P
3)If GI ≠ P then P ≠ NP
As a corollary of the upon propositions we have: if GI is not in coNP then P ≠ NP.
The same holds if NGI is not in NP.
Comment: This is kind of trivial and holds for any NP problem.

coNP certificate for Graph Isomorphism


Are birth records of US adoptees really sealed?

Question: My family history used to be cut and dry...My Mom was adopted to a good home. Taken in by the dentist of her biological mother, an 18 yr old immigrant from Ireland who was impregnated by her employer——a much older prominent Jewish man from Hyde Park in Chicago. As I've become older, I feel this story isn't true. My Mother was born at Cook County Hospital in Chicago, IL. She says her birth records are sealed in a way I've been unable to imagine how and why; the legalities; how do you get through life without a birth certificate? is this possible? Is it impossible to ever discover the truth?
Comment: You could do a DNA test to find out if your percent of Jewish ancestry is what would be expected from this history. You might also find DNA matches.
Comment: What year was this? Fwiw, I believe birth certificates are sometimes created for adoptive parents.
Comment: Hi, welcome to G&FH.SE! Please take the [tour] to learn a little about the site, since the format here is very different than other sites like discussion forums that you may be more used to.  Your question needs some help because it's unclear what you're asking -- you have too many questions in your post.  What is it that you really want to know?
Comment: I hear that you're confused, but the hard facts are that in many states, adoption records are closed, and unless adopted kids happen to find a copy of the court records in their family papers, they don't have access to anything but what's called 'non-identifying' information about their birth parents. As part of the adoption process, they get amended birth certificates issued by the state with the names of the adoptive parents on them.  Adoptees don't have to "go through life without a birth certificate" as you put it.  This is changing, but for many adoptees, the records are still closed.
Answer: In many states, yes, original birth certificates (OBCs) are sealed when a child is adopted. An amended birth certificate is then issued with the adoptive parents' names and the child's new name. So, no, adoptees do not go through life without a birth certificate.
You're somewhat in luck; Illinois, according to the American Adoption Congress partially opened their adoption records. Adoptees born 31 Dec 1945 and earlier can request a copy of their OBC. For adoptees born 1 Jan 1946 and later, they can file for a non-certified OBC (it can't be used for identification), but birth parents, if living, can file a veto and have their information redacted until their death. More information from AAC here.
Of course, there's always the possibility that your mother's birth mother did not name the father on the OBC, or used a fake name. She may have even used a fake name for herself. And falsified the non-identifying information she provided to the adoption agency. So getting a copy of your mother's OBC may not actually provide any decent information.
If you really want to find out who your mother's biological parents are, I recommend going the route already suggested: Take a DNA test. Even better, if your mom is still living, have her take it. There are a couple books by Blaine Bettinger that are great guides for selecting a DNA test (or tests) and interpreting the results. You can also ask further questions here, or there are a number of DNA/genetic genealogy groups on Facebook (including some that specialize in adoption/uncertain parentage cases).