War between Karna and Arjuna - Mahabharata

Question: I have seen many people tell that before the Kurukshetra war in Mahabharata, no war was fought between Karna and Arjuna. But some people also tell that there had been various wars between Karna and Arjuna before the Kurukshetra war in which Arjuna defeated Karna many times. What is the truth? Who was considered more powerful between the two and on which basis?
Comment: I think second question leads to opinion based answers.
Answer: From the article "Karna and Arjuna" by Dr. Madhu Guptan and his comments under the article:

On the basis of evidence from the Mahabharata Arjuna emerges as the greatest warrior. Arjuna humbles Karna many times before Mahabharata war like Draupadi Svayamvar, Virata war and in the killing of Jayadrath. Karna ,Gandharva's attack,  in spite of all his boasting, is neither able to save Jayadrath from Arjuna nor Duhshasana from Bhima. In the Virata war, Arjuna single handedly defeats the entire Kaurava army. Arjuna also has a greater character than Karna.
But Karna too has great and admirable qualities, as mentioned in my article like friendship, loyalty and charity. That is the beauty and complexity of Mahabharata.
Comment: @Rohan yeah i have mention in answer **Virata war**. Virat War was conducted before Mahabharat War, Virat War was at the end of 13th year of Pandavas's exile which they spend incognito to avoid another 12 years of exile in the forest.
Comment: @Garg's Looks like you copied most of your answer from [the article](http://www.boloji.com/index.cfm?md=Content&sd=Articles&ArticleID=1435) 'Karna and Arjuna' by Dr. Madhu Guptan. When you copy stuff you need to credit the author. Please see [here](http://hinduism.stackexchange.com/help/referencing) and [here](http://meta.stackexchange.com/questions/160071/what-to-do-when-plagiarism-is-discovered).
Comment: Nice answer!! Those were the wars I was asking about fought between Karna & Arjun before Mahabharat war.
Comment: In this war When Karna entered the war Arjuna was still Brihannala, the transvestite, Karna took him to be unfit for war till Arjuna retrieved his Gaandiva from the 'Sami' tree. Karna took time to adjust to the situation as well as timing. Timing was that the Kaurava chiefs thought that the time period was not over yet and so were exuberant as if they won. But facts when presented that the period is past, there was a disappointment. It implies that they didn't come so fully prepared for a war of the scale of Arjuna. Even the best with preparation falling short will have to taste defeat.
Comment: Karna never had any fight with Arjuna in Virat war. Isn't it true @sv. ?
Answer: Arjuna is superior to Karna in battle.  Here is what Indra says in a message to Yudhishthira, in this chapter of the Varna Parva of the Mahabharata:

And, O bull of the Bharata race, well do I know that Karna is endued with great ardour and energy and strength and prowess that is incapable of being baffled. Well do I know that, skilled in fierce conflict, he hath not his rival in battle; that he is a mighty bowman, a hero deft in the use of fierce weapons and cased in the best of mail. Well do I know that that exalted son of Aditya resembleth the son of Maheswara himself. Well do I also know the high natural prowess of the broad-shouldered Arjuna. In battle Karna is not equal unto even a sixteenth part of Pritha's son. And as for the fear of Karna which is in thy heart, O repressor of foes, I shall dispel when Savyasachin will have left heaven.
Comment: Downvoting this. Lord Krishna twice said that Karna is better than Arjuna and his statement has more weightage than Indra.
Answer: We all know that Karna and Arjuna clashed several times, such as Swayamvara of Draupadi, Virata war and Kurukshetra.
But the war of Virata and fights before and during the day / night 14 is practically considered interpolated by Vyasa himself:

On seeing that Yudhishthira, Dharma's are, was advancing, Vyasa approached and said, 'Though he has clashed against Karna in the battle, it is through good fortune that Phalguna is still alive, I have preserved the spear, wishing to kill Savyasachi. bull among the Bharata lineage! It is good fortune that Jishnu did not engage in a duel with him.

Source: Drona-Vadha Parva Chapter 1135
So Virata war, group attacks of the 12th and 14th, as well as individual ones do not count. So in these cases we could only use two fights between them that are very famous for everyone: Swayamvara de Draupadi and fight on day 17.
Draupadi Swayamvara:

Seeing Vaikartana Karna rush towards him, the wise Arjuna stretched his mighty bow and
  pierced him with three arrows. The impact of these sharp arrows stunned Radheya and I
  approached with greater circumspection. Then those two invincible warriors fought violently,
  each eager to vanquish the other. That was the speed that they became invisible. "Look at
  the strength in my arms "," See how I countered that ", they taunted each other in words that
  only warriors understand. Seeing the value in Arjuna's arms, unparalleled on earth,
  Vaikartana Karna fought even more vigorously. Repulsing Arjuna's swift arrows, Karna
  shouted out aloud and the warriors applauded his feat.
  'Karna said, "O foremost among Brahmanas! I am pleased with the strength of your arms,
  which do not shoot in battle, and with your persistent control over weapons. Or supreme among
  Brahmanas! Are you Rama, the personification of the knowledge of weapons? Or are you
  Harihaya himself? Or are you Achyuta Vishnu himself? Have you assumed the form of a
  Brahmana to disguise yourself and are now fighting strongly with me for self-preservation,
  Mustering the strength of your arms? When I am angry in the field of battle, not one except
  Shachi's husband
  and Pandava Kiriti can withstand me. "Hearing these words,
  Phalguni replied, "O Karna! I am not the science of weapons personified. Nor am I the
  powerful Branch. I am only a Brahmana, chief among warriors and supreme among those who
  have the knowledge of weapons. Through my preceptor's grace, I have become skilled in the
  use of brahma and paurandara weapons. O warrior! Wait for a bit. I stand here today, to
  vanquish you in battle. "At these words, Radheya Karna withdrew from the battle, because
  the maharatha thought that Brahmana strength was invincible.

According to Vaishampayana, Karna withdrew because Arjuna dominated Karna, but look at this:

Shalya, king of the Madras, rushed at Bhimasena.
  Duryodhana and the others rushed at the Brahmanas, but they fought with them lightly and carelessly.

Also remember that Karna had great devotion to the Brahmins, obviously fought softly against Arjuna. But the Kshatryas applauded Karna that Arjuna, so Karna had to overcome Arjuna in their fight, but to confirm that Arjuna was Brahmin left.
Now your final battle, because it is long and I do not want to extend my answer much, I'm just going to put on exploits:

Karna first pierced Arjuna with ten arrows:

With ten great arrows, Karna struck Partha first.

Karna dominated Arjuna so much that Krishna himself offered him Sudarshana Chakra:

On seeing that Partha's arrows were being repulsed, Vasudeva spoke to him." O Kiriti! How is it that in every way, your weapons are being countered by Karna's weapons? Or brave one! Why do you look like someone who is confused The Kurus are cheerfully roaring.All of them are honoring Karna, knowing that all your weapons have been destroyed by his.In yuga after yuga, you have used fortitude to destroy the weapons of darkness and terrible rakshasas.You slew Dambhodbhava and other asuras in meetings Use that fortitude and slay the son of a suta Or use this sudarshana chakra now and slice off his head.

Karna destroyed Brahmastra of Arjuna with normal arrows:

I have invoked the invincible brahmastra in his mind, in accordance with the prescribed rites." All the directions and sub-directions were covered by extremely energetic arrows. "O bull among the Bharata lineage!" Many hundreds of swift arrows were released from it. Also, I have performed a superhuman deed and pierced Bhimasena, Janardana and Kiriti with three arrows each.

There is no narration after the Brahmastra of Arjuna, obviously it had to be destroyed by the arrows of Karna.
Arjuna killed Sabhapati:

He then shot ten excellent arrows and killed Sabhapati, who was clad in golden armor. The head and arms of that prince were severed. He was without his charioteer, bow and standard. He was mangled and fell down from the chariot, like a shala tree sliced down with an ax.

Arjuna killed a lot of Karna's support and several lines after Arjuna kept doing it until Karna had no support:

I slew four hundred elephants, stocked with weapons, eight hundred rathas, one thousand horses and riders and eight thousand valiant foot soldiers.
In the battle, Savyasachi slew all of them. I have killed two thousand of the foremost Kurus, bulls among the Kuru lineage. O king! In a short instant, the brave one single-handedly destroyed all of them, with their chariots, horses and charioteers. They fled, abandoning Karna. And so did your son and the Kurus who were left.

Arjuna broke the rope of Gandiva, possibly he wanted to kill Karna faster or Karna was faster than Arjuna and the latter wanted to match him:

Pandava's bowstring was being drawn with great force and snapped, with a loud noise

Arjuna pierced the armor of Shalya:

Partha pierced Shalya's body armor with ten arrows and laughed

Karna pierced the armor of Krishna, and the arrows he used came back to him:

However, Adhiratha's are struck him with three arrows." Wishing to slay Achyuta, I have shot five arrows that were like flaming serpents They were decorated with gold and were aimed well They pierced Purushottama's armor with great force and passing through, entered the Having bathed there, they returned to Karna. "

Karna decided to use Ashwasena, he wanted to decapitate Arjuna but thanks to Krishna, he did not do it but he destroyed the celestial crown of Arjuna:

Karna affixed an extremely sharp and flaming arrow that was capable of slaying the enemy This had a serpent in its mouth That terrible arrow had been carefully preserved and washed well, protected well for Partha's destruction. on a bed of sandalwood paste That immensely virulent weapon was lying down in a golden quiver It was generated from the lineage of Airavata and flamed. "

After chatting with Shalya he shot the arrow:

On seeing that Karna had affixed the serpent, Madhava, supreme among strong ones, used his strength to press down on the chariot with his feet. The chariot sank down on the ground and the horses sank down on their knees. '"The arrow struck down the intelligent one's diadem. The ornament that adorned Arjuna's head was famous throughout the earth, heaven and the waters. In his anger and through the strength of his weapon, the son of a suta used the arrow to bring it down from his head. It possessed the flaming radiance of the sun, the moon and the planets. It was decorated with nets of gold, pearls and gems. Using his austerities and efforts, this had been crafted for Purandara by the earth's are himself. It was extremely expensive in form and generated terror among the enemy. It was fragrant and brought happiness to the one who wore it. When I killed the enemies of the gods, the Lord of the gods was delighted and himself gave it to Kiriti. It could not be destroyed by Hara, the lord of the waters or the protector of riches, and by the pinaka, pasha or vajra and the best of arrows. The supreme gods were incapable of withstanding it. However, using the serpent, Vrisha now destroyed it.

Here would have to be the part where Arkuna cuts Karna's armor, crown and earrings but look at this:

Karna had possessed armor, ornaments, garments and weapons.

This is the state of Karna's corpse when Duryodhana came to see him. Obviously for ornaments refers to the earrings and the crown. Therefore, Arjuna destroying Karna's earrings, crown and armor was simply a glorification of the hypocritical Sanjaya.
Karna destroyed Aindra weapon of Arjuna:

Arjuna invoked mantras and released aindrastra. Dhananjaya also invoked mantras on the bowstring of Gandiva and the arrows. I have released showers of arrows, like Purandara pouring down rain. Those energetic arrows issued from the immensely valuable Partha's chariot and were about to destroy Karna's chariot. However, when they arrived in front of him, Maharatha Karna repulsed all of them.

Karna destroyed a bowstring of Gandiva:

But Karna used extremely energetic arrows to angrily sever his bowstring.

Karna invoked Brahmastra but Arjuna neutralized him:

Karna again invoked brahmastra against Dhananjaya. I have showered down arrows and tried to extricate his chariot. Pandava countered those weapons with his own weapons.

Arjuna invoked Agneyastra but Karna neutralized him with Varunastra:

Kounteya then released another weapon, beloved of the fire god, towards Karna, It blazed fiercely, Karna pacified the fire through a varuna weapon.

Arjuna destroyed Karna's banner:

Kiriti used a razor-sharp arrow that was gold-tufted and pointed with that, I have brought down the handsome and blazing standard of the great-souled maharatha, Adhiratha's are.

Arjuna finally killed Karna in an apparent fair battle, but unfortunately Arjuna killed Karna by cheating, according to Krishna and gandharvas, apsaras and siddhas:

On hearing that Bhishma, Drona, Karna and Bhurishrava had been slain through adharma, they grieved and wept in sorrow. The Pandavas were distressed and immersed in thought. On seeing this, Krishna spoke these words, in a voice that rumbled like clouds and drums. 'All of them were swift in the use of weapons and were Maharathas. In a fair fight, even if we fought bravely, we were incapable of defeating them in the battle. That is the reason I thought of means to slay those lords of men. Otherwise, the Pandaveyas would never have obtained victory. Those four great-souled ones were atirathas on earth. 56 Following dharma, even the guardians of the world would not have been able to kill them. Even when he is exhausted.

After the war, Krishna got off the divine chariot of Arjuna burned due to the Brahmastra of Karna, not the one of Drona since Arjuna had destroyed it:

Take pleasure to the wielder of Gandiva and spoke to him." Take down Gandiva and the two great and inexhaustible quivers.O supreme among the Bharata lineage! I will get down after you have dismounted .O unblemished one! Descend. your own good. 'Dhananjaya, Pandu's brave are, did as he had been asked, Thereafter, the intelligent Krishna discarded the reins of the horses and got down from the chariot that belonged to the wielder of Gandiva. The extremely great-souled one, the lord of all beings, descended The celestial ape, stationed on the standard of the wielder of Gandiva, disappeared Earlier, it had been burnt by the divine weapons of the maharathas, Drona and Karna O Lord of the earth! amidst a fire and was swiftly burnt The chariot of the wielder of Gandiva was burnt, with its yokes, its harnesses, its horses and its lovely joints O Lord! On seeing that it had been reduced to ashes, Pandu's sons were astounded. O king! Arjuna joined his hands in sa lutation and bowing down affectionately, asked, 'O Govinda! O illustrious one! Why has the chariot been burnt down by the fire? Or descendant of the Yadu lineage! What is this extremely wonderful thing that has occurred? O mighty-armed one! If you think that I deserve to hear it, tell me. 'Vasudeva replied,' O Arjuna! This has been burnt by many different kinds of weapons. O scorcher of enemies! It is because I was seated that it was not destroyed in the battle. It has now been destroyed, consumed by the energy of brahmastra.

Arjuna destroying Drona's Brahmastra:

The immensely intelligent Drona invoked brahmastra. It scorched Partha and all the invisible beings. The earth, with all its mountains and trees, began to tremble." Turbulent winds began to blow and the oceans were agitated. weapon, there was terror among the Kuru and Pandava soldiers and all the beings and a great uproar arose.O Indra among kings!, Partha was not frightened.He counted that weapon with his own brahmastra and everything became peaceful again.

Karna's Brahmastra:

Using his strength, I have invoked brahmastra. On seeing this, Arjuna invoked mantras and released aindrastra Dhananjaya also invoked mantras on the bowstring of Gandiva and the arrows. the immensely valuable Partha's chariot and were about to destroy Karna's chariot, however, when they arrived in front of him, maharatha Karna repulsed all of them.

There is no narration of Arjuna counteracting that Brahmastra.

Conclusion: Karna was much better warrior than Arjuna, even in piercing the armor of Krishna, although Arjuna also did what Karna was more impressive since the arrows returned to him.
Comment: Use appropriate text-formatting for better readability. e.g. [block quotes](https://hinduism.stackexchange.com/editing-help#simple-blockquotes) for quoting the text. Also mention the reference from where you're copying the content. See [How to reference material](https://hinduism.stackexchange.com/help/referencing).
Comment: 'But the war of Virata and fights before and during the day / night 14 is practically considered interpolated by Vyasa himself' - where does Vyasa say it's interpolated? Are you using Bibek Debroy's translation? If so, you can leave a link to his book on Amazon.com or at least credit the author.
Comment: _There is no narration of Arjuna counteracting that Brahmastra_ - Disagree - see [this](https://hinduism.stackexchange.com/a/29742) answer. You should format your answer for readability. [It's not too hard](https://hinduism.stackexchange.com/editing-help).
Comment: That was the second Karna shooting, the Brahmastra that burned Arjuna's chariot was the first
Answer: As per the authentic Mahabharata verses, texts, quotes, scriptures & reality it is clear that Arjuna is more superior to Karna, he was considered more powerful than karna.
Let me debunk one argument of Karna fans this arguments has evidence in the text not a fake one like the chariot pushing story.

Vyasa claiming that the fights between Karna and Arjuna (before the 14th night are interpolated) none of this is true because Vyasa himself said that karna did encounter Arjuna before the 14th night.

Here:

"Vyasa said, By good luck, Phalguna liveth still although he had
  encountered Karna in battle."

http://www.sacred-texts.com/hin/m07/m07180.htm
Note the "he had encountered". This means that karna and arjuna fought eachother before the 14th night, so none of those wars were interpolated.
Reasons why Arjuna is better than Karna.

Arjuna defeated Karna many times but karna never defeated Arjuna.
Arjuna defeated warriors like Drupad, Gandharvas etc (these are the same warriors that defeated Karna with ease).
Arjuna defeated the 30 million Nivatkavacha demons while he was battling underwater (karna was defeated by a group of foot soldiers from Ghatotkatcha's army, and even Ghatotkatcha defeated karna too a few times), Arjuna defeated more demons than karna ever did.
Arjuna strung the bow that Karna failed to string. (Note that karna failed to string Draupadi's bow as per authentic texts of Mahabharata).
Arjuna slayed Karna's comrades infront of his eyes. (Examples: Karna's foster brother Sangramajit in virat parva, Karna's two other foster brothers on the 12th day, Jayadratha on the 14th day, Vrishasena [karna's own son] on the 17th day). Ghatotkatcha was killed with a divine weapon, all of karna's comrades (with the exception of Jayadratha) were slain by ordinary arrows that Arjuna used. Abhimanyu was killed by Duhsasana's son, that too when Arjuna was not their.
Arjuna trained warriors that defeated karna many times. Arjuna trained krishna's son Pradyumna (the same Pradyumna that tied up karna and tossed him into a cave of illusion according to Harivamsa), Abhimanyu (he trained him during his Indraprastha days) defeated karna many times on the 13th day, Satyaki (defeated karna on days 12, 14, 15, 16, 17 and night 14).
If people want to say Krishna saved Arjuna from a arrow that never hit him like Ashwashena then they should realize that Sakuni also saved Karna from Bhima's dart that never hit karna.
Mahabharata says in many places that karna was jealous of Arjuna but nowhere is it ever written that Arjuna was jealous of karna.
Arjuna was praised by many characters like Shiva, Parshurama, Vyasa, Bhishma, Drona, Duryodhana, Dhritarashtra as the greatest archer and warrior of Mahabharata far better than karna. Krishna praised karna twice but also said that Arjuna is better than Karna.

Quote (KMG):

"There are also Bhishma, and Drona, and this Karna, and Kripa, and
  Bhurisrava, and Somadatta, and Aswatthaman, and Jayadratha. All these
  together are incapable of fighting against Dhananjaya. Indeed, Arjuna
  is incapable of being vanquished in battle even by all the gods,
  Asuras, men, and Gandharvas. Do not set thy heart for battle."

http://www.sacred-texts.com/hin/m05/m05124.htm
Answer: Since there seems to be too many varying opinions, I would like to add the concrete points of comparison. I will list my points objectively and give my conclusion later.

Teachers and Education
Arjuna was taught by Kripacharya and Dhronacharya in all the arts and politics needed for a prince. Meanwhile Karna was rejected by Dhrona and learnt everything on his own with his brother by appointing Lord Surya as his guru. The famous eye shot account of Arjuna in which he could see only the eye of the bird which was his target is known. When Karna heard of this, he hung a bird =, strung two arrows and shot both eyes of the bird in dark, since he always practises in the after hours.
Weapons, Boons and Curses.
Arjuna was taught to use the astras by Indira who also gifted him with his Vajra. He could also use the astras of all the devas and the major astras including Brahmastra and Pasupathastra. He wielded Gandipa created by Brahma and rode a chariot gifted by Lord Agni with Lord Hanuman as the flag protecting him from everything. He also had Lord Krishna on his side protecting him from all the dangers that could ever harm him. Arjuna was also one of the two people who could use Brahmadhanda, a weapon 4 times more powerful than Brahmastra.
Karna was born with earrings and armor which would protect him from all harm. Lord Indira disguised as a Brahmin asked for them as alms and Karna gave them away, thereby loosing his most powerful defense. In retrospect, Indra gave him his most powerful weapon to be used only once, but Karna was forced to use it to slay Kadochgadha. He trained under Parasurama but was cursed with the inability to use Brahmastra when he needed it the most. The curse of chariot getting stuck in mud has already been told.
The reference to Adhiratha and Maharatha
Bhisma knew about the ancestory of Karna and he did not want him to enter battle. He knew he will fall in the war and wanted someone to protect Duryodhana when he is gone. Thus he insulted Karna and made him enter the battle only when he was gone.

Looking at all the things said above, it would look like Arjuna is the greatest warrior. Even without Lord Krishna, he had many powerful astras and an almost indestructible chariot.
But what does a warrior make? Is it his brute strength or just skill with weapons?  If yes, Karna is superior to Arjuna in even that facet. One the sixteenth day of battle, Karna defeats all the Pandavas in battle. He destroys all the weapons thrown at him by Arjuna and disarms him completely. Arjuna is saved by the end of the battle day since it was the ethics that both sides observed to not fight after the decided time.
Both Arjuna and Karna are warriors of equal skill and forte. Either one of them could have easily destroyed each other on equal footing. But for me, Karna is the best warrior of the two.
Karna did not have the upbringing or the status of Arjuna. Arjuna was taught by the best teachers while Karna learnt every basic skill himself. Arjuna was praised and welcomed where ever he went while Karna was always shunned because of his birth. Karna was not invincible. He did not have a god protecting him, nor an indestructible chariot which could stand against any attack. Arjuna had the best of everything, upgringing, education and blessings. Still Karna was able to fight on equal footing with Arjuna and cut his bowstrings and even managing to disarm him while Arjuna killed Karna only because of all the curses on him , tricks of Krishna and the repercussions of his alliance with Duryodhana.
Arjuna was one of the best warriors and without doubt THE best warrior on the side of Pandavas. But for the above reasons, Karna is the greater warrior of the two.
Who's more powerful?
When the piece of Karna Vs Arjuna is taken  in Mahabharatha it shows clearly how a person better in all aspects can end up losing because of his choice of right or wrong !
So if you take Dharma out of the equation, Karna is better than Arjuna. But Dharma being the multiplying factor can multiply or diminish strengths.
Krishna never suffered ! He is the paramatma himself who ran all the show ! He is a factor to be considered outside the Mahabharatha equation !
Further the so called tricks are not tricks and the fall of Yadava empire is due to a different story and certainly not due to the "tricks" played by Krishna.
For more:
Wikipedia: Karna
Wikipedia: Arjun
Karna and Arjuna - Valiant Brothers at War (by Priya Viswanathan)
Comment: In your answer, you have mentioned everytimes that `Arjuna was taught by the best teachers while Karna learnt every basic skill himself.` But Karna was taught by the teacher of Arjun's teacher who was greatest of all time i.e `Parshurama`. I am not talking about the Mahabharata war. I am talking about the wars fought before Mahabharat war where everytime Arjun defeated Karna.
Comment: Superb explanation, but haven't answered the question fully!
Comment: I think this is a link of the article you are looking for http://www.boloji.com/index.cfm?md=Content&sd=Articles&ArticleID=1435
Answer: There win occur one opportunity for his slaughter. When his car-wheels will sink in the earth, availing thyself of that opportunity, thou shouldst slay him in that distressful situation. I will make thee a sign beforehand. Warned by it, thou shouldst act. The vanquisher of Vala himself, that foremost of heroes, wielding his thunder, is incapable of slaying the invincible Karna while the latter stands weapon in hand
reference http://www.sacred-texts.com/hin/m07/m07177.htm
The above text is krishna telling Arjun that the only way to kill Karna is when he is unarmed. I think that is enough proof that Krishna definetely considered Karna better than Arjuna
Comment: Krishna also said that Shalya and Satyaki are better warriors than karna.
Answer: for your second question :
I am a huge admirer of Karna, but after reading KMG from here .
I had to change my opinion on "Karna was the best warrior from Mahabharata"
because from the war it is clear Karna's first best day as a warrior was the first worst day for Arjuna as a warrior.
The main reason I am siding with Arjuna is that he's consistent from day 1, whereas Karna lacked consistency be it Gandharva skirmish, Virata war, Karna always had to find excuses.
The only day I find Karna to be untouchable was during the 14th night and 17th day,but still Arjuna maintained his consistency for instance after Krishna interferes with Nagastra of Karna, Arjuna escapes from sure death, but his comeback after that just humbles Karna, but sure Karna too comes back that day
But in the end who knows what would have happened if Karna had used his Vijaya bow from day one,a different charioteer in the 17th day would have changed everything.
Sure Arjuna is a god-like warrior,but someone who's matching that level must also be a god-like warrior.
If I had to choose the best warrior from Mahabharata, I can either choose Arjuna or Karna (from the 17th day alone) , I don't see any other warriors like Bhisma,Drona taking up these two places, I believe it is reserved for Arjuna and Karna alone.
Answer: Draupadi Swayamvara war
Karna was fighting mildly as he did not wanted to kill him.

Both Karna and Arjuna fought vigorously. Karna cut down all arrows of Arjuna and later he realised that he was a Kshatriya. Karna realised that he could not defeat him fighting mildly and retreated. On other hand, Arjuna told lie to Karna to save himself. So, It was a tie.

Virat war

Here, Karna was defeated by Arjuna
Kurukshetra war day 17

Parthas indicate Arjuna and Bhima. In the last lines, it is written that all warriors fled away in different directions. Here,Karna defeated Arjuna.
Conclusion:- So both the warriors conquered each other once. Other combats between them were either not clear or there was no real and fear combat like final encounter so I did not included it.
Comment: Arjun was away fighting the Samsaptakas. So he can't be there to attack Karna. Parthas are sometimes used to just refer to Pandava army.
Answer: I am giving answer to Syamantak Sinha article.  I am simply asking you to learn any skill on your own and compete with another who learned with skillful gurus.  There must be a clear difference.

first point Arjuna can have more celestial powers than karna (is it true or not)
things gone in Arjuna's favour at each and every occurrence.
If Arjuna is superior than Karna, why Indra begged his kavach kundal as brahmin saint.
As karna resides behind adharma, bcoz of this only he got bad.
Why Arjuna was not faced Karna when he was having powers given by Indra?
One thing I would like to say "Winners write history" i.e. the main thing.
In the war, there is no sympathy to any character.
If Parasurama has not given curse, karna would have fired Brahmastra on Arjuna.
How Arjuna escaped "Thakshaka"'s celestial power?
During fighting Salya (i.e. Sarathi) disturbed Karna in the war (loosing concentration).
How Arjuna escaped Narayana Astra fired by Karna.
On 16th and 17th day, Karna only killed 1.8 akshouhini (count of army) pandava's army.
He has not killed remaining pandavas giving life to them in the war.
Think once my points
Comment: Welcome to Hinduism SE! Answers on this site should be elaborate enough to solve the questioner's doubts and should contain relevant texts from Hindu scriptures, eg, Vedas, Puranas, Upanishads, etc to support your answer. Please either edit your answer to provide more details or delete/comment instead.
Answer: SOURCES:Mahabharata epic:- Karna Parva and Shanti Parva
<code>                       Wikipedia The Free Encyclopedia
</code>
Arjun and Karna were great warriors.But I strongly believe that Karna was stronger than Arjuna.There are a lot of misconceptions about the Virat war.
During the Virat war lord hanuman were sitting on the chariot of arjuna and thus protected his chariot from the weapons of maharathis.
During the virat war arjuna used his gandiva bow whereas karna used his ordinary bow and thus his bow was broken by arjuna.
karna possessed the vijaya dhanush which was the strongest bow of all the bows.It was the bow of lord shiva and therefore there cannot be any impact of even the mighty pashupatastra on it which made karna invincible.The name of the bow itself suggest "victory".
It was karna who knew that he was pandavas elder brother and thus when he fought during the war there was a feeling of sympathy for the pandavas.
Also karna finished 3 akshauhini sena in 6.5 days whereas arjuna killed 5.5 akshauhini sena in 18 days.This shows the superiority of karna.
Karna and Arjuna were sworn enemies in the epic, each having taken an oath to kill the other in the battle. Anticipating a likely battle to the death between Karna and Arjuna, Krishna warned Arjuna calling Karna to be the foremost of the heroes and in some versions he also referred Karna as greater archer than Arjuna.
On the sixteenth day, he fought with all the Pandava brothers, defeated them all in direct combat and spared each one of them after insulting them with harsh words. After the terrible death of Dussasana, he ordered his charioteer Shalya to move towards Arjuna, Karna deciding to finish him off for once and all. So violent and offensive were Karna's attacks that Arjuna's defenses soon crumbled before it. Karna then moved in for the kill. He arms his Nagastra, the same celestial weapon that was used by Indrajit against Rama in Ramayana. Intervening, Shalya tells him to aim at Arjuna's chest. Frustrated at Shalya's constant insults, Karna believes that the advice must be bad, and instead aims at Arjuna's head. Krishna saved Arjuna from certain death by lowering their chariot wheel into the earth; the arrow strikes Arjuna's helmet instead of his head. Karna and Arjuna then waged a rough war against each other. As promised to Kunti, Karna used a celestial weapon only once against Arjuna. Regaining the upper hand, Karna has a chance to kill Arjuna but spares the latter as the sun was about to set. In some versions, Lord Krishna realized that only miracles can save his ward Arjuna from death and caused the Sun to set prematurely.
On the seventeenth day of battle Karna used Bhargavastra against the Pandava army. When Bhargavastra was invoked into existence for the first time in history, there appeared millions and millions of ultra sharp arrows with blazing appearance. The sky was so filled with arrows that it appears like a cloud of arrows and even visibility was lost in the rain of arrows. The earth trembles and these arrows hit and killed hundreds of thousands of men, steeds, elephants and destroyed countless chariots .This astra almost exterminated the Panchala's and the Chedis. Whoever opposes the weapon become dead and the entire Pandava army ran away from the battlefield fearing this weapon.[43] Even Krishna and Arjuna had to run away from the battle field in order to escape from that weapon.
Krishna then took Arjuna away from the battlefield in order to escape from Bhargavastra and visited Yudhisthira who were outside the battlefield mortally wounded by Karna's astra's. Seeing their plight, Karna repeatedly challenged Krishna and Arjuna to come face him in battle, but Krishna kept Arjuna away from the battlefield. The Bhargavastra destroyed an Akshauhini of Pandava forces and earth appeared like an ocean of dead beings. Yudhisthira insulted Arjuna for running away from Karna
In some versions of Mahabharata, Parasurama appeared in Karna's dream during the night of 15th day of battle, as requested by Lord Krishna. In order to protect Arjuna and Dharma, Krishna sought the help of his previous avatar. The avatar Parasurama explained to Karna that if he killed Arjuna, Duryodhana and chaos would ensue.[54] Parashurama asked Karna to accept death and asked him to die at the hands of Arjuna, so that the world might live in peace. Karna protested to this idea but Parasurama asked this as his Guru Dakshina. Previously, Karna never had a chance to pay his Guru Dakshina; Parasurama never asked for it either. Severely, Parasurama reminds Karna that whatever he became or attained in his life is due to the knowledge he gained from his guru. Karna accepted his guru's words and promised he would never kill Arjuna.
also after the war finished lord krishna told that it was due to lord hanuman and himself that his rath is still in a good condition. Lord hanuman told arjuna that he protected arjuna from all the weapons but was not able to protect him from the weapons of karna. Then arjuna said that the chariot is still in a good condition.Then lord hanuman removed his flag from the chariot and at that particular point of time the chariot was destroyed and the chariot got blasted.
These all instances show that karna was greater warrior than arjuna.
Comment: you need to provide suitable references(preferable from scriptures such as Mahabharata) while posting answer to this site.
Comment: @DivyanshuYadav You don't have to mentione the source name but integrate source link too. And one more point, wikipedia is not fully believable, so its better if you can find some scriptural reference.
Comment: It is not matter of me believing it or not in those scriptures. As per this site's rule, you should cite sources when writing the answer. Check the Help centre for more info : http://meta.hinduism.stackexchange.com/questions/190/lets-stop-asking-for-sources-everytime?rq=1
Comment: @DivyanshuYadav See [guidelines](http://meta.hinduism.stackexchange.com/q/478/3500) . This is to ensure quality of the site and don't take it wrong way.
Comment: @DivyanshuYadav Do you know how editing work on Wikipedia? Previously anyone can edit it and then they validate it later on and sometime they even don't but now they accept edit which provide some outside source but i can't see if they validate those outside source and how they even achieve that. They accept source from any site, even some blog site too. [It's been discussed here](http://meta.hinduism.stackexchange.com/questions/151/is-it-ok-to-cite-wikipedia-in-answers). Even sometime Wikipedia also have a message on there post if it's present with un-sourced information or highly edited too.
Comment: The main problem here is that you didn't even provided the Wikipedia link too, you just mention its taken from Wikipedia but which page?
Comment: these all are the instances mentioned in the mahabharata itself.If you dont believe it you can study the karna parva and the shanti parva mentioned in the epic mahabharata.
Comment: i have added the sources . Is it ok now
Comment: @DivyanshuYadav You have to cite sources for your answer so that users who didn't read Mahabharata can get a comprehensive idea of your answer. Here is the [full version of Mahabhartha](http://www.sacred-texts.com/hin/maha/) and you can post sources for war scenes in Answer.
Comment: i have written the sources.And by the way whom do you think was stronger between karna and arjuna
Comment: wikipedia is not fully believable who told you that


Bayesian trade probability with factors

Question: I have a strategy Y which is influenced by some factors X1, ..., Xn (for example asset volatility, distribution of macroeconomic factors). At moment t0 I have historical distribution(prior) of X1, ..., Xn and Y (past strategy performance). How can I model expected distribution of strategy performance(Y_posterior) based on the most recent information about X1, ...., Xn. How can I model that? This sounds like Bayesian inference problem with Markov Chain Monte-Carlo (MCMC) used to model conditional distribution, can we model this problem with that and how?
Comment: I assume Y is log return?
Comment: It can be log return, underlying price distribution
Answer: There appears to be some confusion on how Bayesian methodologies work and their differences to null hypothesis methods such as Pearson and Neyman Frequentist, Fisher's Likelihoodist or Chebyshev's method of moments.
Having old data is not a prior distribution.  That is the data.  It is the same for all modeling methodologies.  The prior distribution describes everything you know about where the parameters are at that is not contained inside the data itself.
Imagine you were doing research on the calories in a new variety of green beans.  A good estimator of calorie count would be estimates of calorie counts in other varieties of bean.  Your prior density may be the average calories in a sample of Phaseolus coccineus and you could estimate the variability of the estimate of the variance in the same way.  This generates a far more accurate answer and controls for things such as the odd chance of getting a weird sample.  It is related to the concept of shrinkage estimation in Frequentist statistics.
MCMC is used to perform numerical integration on those Bayesian problems where there cannot be an analytic solution.  Many simple Bayesian problems have analytic solutions and you should not use MCMC if your regression can be restated in that way.  MCMC is only used to calculate the denominator's value in Bayes theorem and may not be necessary even without analytic solutions depending on your very specific problem.  This is because the posterior density is proportionate to the numerator.
Bayesian methods differ substantially in the understanding of how things work.  For example, there is nothing similar to a t-test or an F-test.  Indeed, the idea of an F-test for regression has no analog in Bayesian methods.  The idea of testing that all parameters are equal to zero is called a sharp null hypothesis and there is no way to test a sharp null in Bayesian thinking, though there are rough analogs that do not mean the same thing.
In null hypothesis methodologies, the sample is random and the parameters are fixed.  In Bayesian methods, the sample is fixed and the parameters are random.  Even randomness has a different meaning.  Because you are fixing the parameters with a null hypothesis, randomness is due to chance alone.  With Bayesian methods, there is nothing similar to a null hypothesis.  You can have as many or as few hypotheses as you need and none of them are special in any way.  There is no such thing as an "alternative" hypothesis as they are all alternatives.  Randomness in Bayesian thinking is uncertainty.  You are uncertain as to the value of the parameter, but you are not uncertain as to the value of the data that you saw.  It cannot be random, you saw it.
If you decide you would like to use Bayesian methods because of their greater accuracy, as Bayesian estimators cannot be stochastically dominated, then you need to pick up an undergraduate textbook on them first and work your way forward.  They don't even calculate the estimator of the mean the same way.  There is no x bar.  There is no s squared.  No t-tests, no F tests, no Kolmogorov-Smirnov test.  There is no null.  There are also no confidence intervals, they use a very different construction called a credible interval.  Not even close to similar.  They can even be disconnected.  While an appropriate Frequentist confidence interval may be (-7,5) the same Bayesian interval may be (-6,-4) unioned with (2.5,3.5).  If that is a 95% interval that would imply that there is a 95% chance that the true value of the parameter is inside one of those two bounds.
I would start with Bolstad's undergraduate book introducing Bayesian statistics and really work the examples, even on the solutions you know because they could come out very different.  He also produces a computational methods book as well that follows on.  Do not start with it.  There are other books as well.
There is a good discussion on Bayesian and Frequentist intervals that will give you a very good feel of how different they are by modeling cookie jars at the stack exchange discussion on intervals.
Finally, predictions in Bayesian thinking revolve around the Bayesian predictive distribution.  It is easier to calculate than equivalent Frequentist predictive intervals and makes more sense for most problems.  However, if you are testing a model that involves prediction, you will need to learn about prediction scoring methods.  After you have grounded yourself in Bayesian methods, pick up Parmigiani's book on "Decision Theory," otherwise you are in danger of improperly accepting or rejecting a predictive system.

Bayesian trade probability with factors


How can it be single characters for new chemical elements like 鈽 and 鈾?

Question: I found that most chemical elements (ones I checked) are denoted by single character in Chinese. This is understandable for historical elements, but how it can be for new elements like Uranium and Plutonium? Does this means, that chinese people can invent new characters nowadays?
Comment: For heavy elements, they use [金 Radical: (#167)] pairing with the transliteration of the beginning of the English word.  That creates an unique character that has no other meaning except for the element itself.
Comment: All chemical elements are denoted by a single character. They've been either inventing new characters or re-using old ones from antiquity that matched either meaning or sound to do this.
Comment: Not just  any Chinese people. It is Chinese scientists and linguistics expert come to a consent on naming a new element. And yes, they do create new words
Comment: @TangHo so, character for plutonium is new? it was never used in ancient books?
Answer: You're right. We did invent a bunch of characters for chemical elements in 20th century.
We made it just one character by combining different radical(偏旁) together,  but people can associate them with the English words simply by their pronunciation.
You can read more about it from this Wiki article: Chemical elements in East Asian languages
Answer: Yes, we do invent new characters, but it's more common that the character was invented long ago and dead, and we just resurrect it to be the character of a chemical element.
In the past, only the emperors had the right to invent characters. In Ming Dynasty, the first emperor made the rules that one of the comprising characters of an imperial kinsman's name must contain one of the  "five elements"("五行" 金 木 水 火 土)radicals In it. However, there weren't adequate elegant characters meeting the requirements. So they contrived many characters for this only purpose. These characters contribute to naming many chemical elements.


Increase number of ttys

Question: I am running Raspbian 9 on my RPi 3 B+ and I have only 6 usable ttys (Ctrl-Alt-F#) while other are blank with blinking cursor. ls /dev lists 64 such ttys. How do I enable/run something on them?
Comment: You want to turn on more gettys. Look at https://raspberrypi.stackexchange.com/questions/31321/raspbian-reduce-number-of-tty and do the opposite.
Comment: https://unix.stackexchange.com/ might have a solution. I think `systemd-getty-generator` should be looked at.
Answer: You can switch ttys from the command line using
sudo chvt 55

This is handy when you run out of Fn keys.
To create a new virtual terminal and run something on it, use openvt - for example
sudo openvt -c 55 bash

Have a look at man openvt for more details.

Full disclosure: I don't have access to a Pi connected to a monitor at the moment, so this is tested on Ubuntu. I believe it's fairly standard.
Comment: Thanks, that's just what I needed!
Answer: Question

How come Rpi3B+ Raspbi9 has 50+ TTYs, but I can only use 6?  How can
  greedy me grab more TTYs?

Answer
Well, "tty", or "TeleTYpe", like TeleVision, in the stone age, the tele-typewriter ("typewriter" in turn, is ancient, belonging to my grandmother days) is just a "terminal" to which user inputs something, then system outputs something (sort of GIGO - garbage in, garbage out! :)

A terminal can be a real thing, eg, a bank ATM (Automated Teller Machine/Terminal.  BTW, real banks and real human tellers are disappering, being replaced by virtual banks/virtual tellers) , where you input some "logic" thing, say, numbers, ATM returns you real money.  How nice!
For Windows and Linux, where everything is a "file", TTY can be a simulate/emulate/"process" thing, eg puTTY, which is a software/process thing, emulating a terminal (don't ask me what is the different between "simulation" and emulation - google it! :).

And for greedy newbies wanting more TTYs, I usually recommend to play
  with real USB TTL adapter/cables.  "TTL" here refers to UART/RS232 in
  TTL (Transistor Transistor Logic, but those adapters are actually not
  using TTL, but CMOS).  The more real USB/TTY adapters you use, the
  more fake terminals you have.

How confusing!  Go read the references below to clarify your mind.  But there is no guarantee that the more your read, the more you become confused! :)
References
Linux tty Command Tutorial for Beginners - HowToForge
Q1. What is tty?

In essence, tty is short for teletype, but it's more popularly known
  as terminal. It's basically a device (implemented in software
  nowadays) that allows you to interact with the system by passing on
  the data (your input) to the system, and displaying the output
  produced by the system.
ttys can be of different types. For example, graphical consoles that
  you can access with the Ctrl+Alt+Fn key combination, or terminal
  emulators like Gnome terminal that run inside an X session. To learn
  more about tty, head here

Q2. How tty command works?

Usage is pretty straight forward - just run 'tty', and the output will
  contain name of the terminal connected to standard output (or, in
  other words, name of the current terminal).

Why are there so many [more than 50!] /dev/tty in Linux? - superuser.com

The ttys are not just input/output devices. They also do a special job
  of acting as the controlling terminal for a session, like sending
  signals (Ctrl+C). /dev/ttyNN are virtual consoles, which are full
  screen displays on the monitor.
/dev/tty0 is a special device, which points to the current terminal.
  So, irrespective of where you run it from(any virtual console),
  anything read from/written to tty0 goes to your current terminal.
/dev/tty is at process level, it can be ttyn(tty1, tty2,...),
  ttySn(ttyS0, ttyS1), pty(pts/0, pts/1), and something else.
/dev/tty0 is a alias of current(foreground) virtual console, so it
  could be tty1, tty2, and so on. Notice that ttyS0 is not a alias; It's
  the first serial port.
/dev/console is the system console, it points to /dev/tty0 as a
  default. It can be ttyn, ttySn, ttyUSBn, lpn, and so on.
Roughly, /dev/tty > /dev/cosole > /dev/tty0

How many serial ports are on the Pi 3?
Options to add 20 UART to RPi

Increase number of ttys


Can a girl marry her sister's husband?

Question: One man married a girl. After marriage, the wife became mentally ill. She had two children who lived with their khala (aunt). Now 12 years of marriage have passed but there is no improvement in the wife's condition. Now the husband wants to marry her sister. Is this permitted according to Islam?
Comment: possible duplicate of [What kind of relations are explicitly forbidden in Islam for marriage?](http://islam.stackexchange.com/questions/8943/what-kind-of-relations-are-explicitly-forbidden-in-islam-for-marriage)
Answer: in Islamic rules,  marriage with the sister of wife is forbidden and is not possible. the holy Quran explicitly refers to this judgment in Surah Nisa, verse:23, as follow:
Arabic:

حُرِّمَتْ عَلَیْکُمْ أُمَّهَاتُکُمْ وَ بَنَاتُکُمْ وَ أَخَوَاتُکُمْ وَ
  عَمَّاتُکُمْ وَ خَالاَتُکُمْ وَ بَنَاتُ الْأَخِ وَ بَنَاتُ الْأُخْتِ
  وَ أُمَّهَاتُکُمُ اللاَّتِی أَرْضَعْنَکُمْ وَ أَخَوَاتُکُمْ مِنَ
  الرَّضَاعَةِ وَ أُمَّهَاتُ نِسَائِکُمْ وَ رَبَائِبُکُمُ اللاَّتِی فِی
  حُجُورِکُمْ مِنْ نِسَائِکُمُ اللاَّتِی دَخَلْتُمْ بِهِنَّ فَإِنْ لَمْ
  تَکُونُوا دَخَلْتُمْ بِهِنَّ فَلاَ جُنَاحَ عَلَیْکُمْ وَ حَلاَئِلُ
  أَبْنَائِکُمُ الَّذِینَ مِنْ أَصْلاَبِکُمْ وَ أَنْ تَجْمَعُوا بَیْنَ
  الْأُخْتَیْنِ إِلاَّ مَا قَدْ سَلَفَ إِنَّ اللَّهَ کَانَ غَفُوراً
  رَحِیماً

English:

Forbidden to you are your mothers and your daughters and your sisters and your paternal aunts and your maternal aunts and brothers'
  daughters and sisters' daughters and your mothers that have suckled
  you and your foster-sisters and mothers of your wives and your
  step-daughters who are in your guardianship, (born) of your wives to
  whom you have gone in, but if you have not gone in to them, there is
  no blame on you (in marrying them), and the wives of your sons who are
  of your own loins and that you should have two sisters together,
  except what has already passed; surely Allah is Forgiving, Merciful.

man can marry with the sister of his wife in some cases as follow:
if the first wife dies.
if the first wife divorced by husband.
in above question, presupposition is that the wife is Alive and is not divorces but she is mental.in that case, if man want to marry with her sister, then he must conduct according to this rules such that either man put a way first wife or expect to die his wife.
source:
Imam Khomeini, Tahrir Al vasilah, vol.2.p.280
Comment: "put a way first wife" - what does this mean? does not it mean to divorce first wife?

Can a girl marry her sister's husband?


How to secure 20 lb light fixture install?

Question: What is the simplest (easiest) method to properly secure the light fixture to a ceiling?  Fortunately, the electric box is already in place.  I believe the ceiling is drywall
Comment: Leave as much wire on those ballasts as possible, and sell em on ebay.  You really don't need the ballast in the fixture and it will reduce weight a lot.
Answer: Toggle bolts. Put them in the drywall on either end. There's no chance it will pull out.
Let me expand on this by telling you a true story. I bought a house that had been reposessed by the bank. I can only assume the previous owners ransacked the place (even the fireplace mantle had been removed) and the bank had hired a contractor to come in and replace all the light fixtures. So he put a new fluorescent light (not dissimilar to yours) up in the kitchen.
With screw-in drywall anchors (insert duhn-duhn-duhnnn here).
This is what my wife walked into one morning not long after we moved in.

The screw-in anchors are rated for the weight, but not the parallel downward force (they're designed for perpendicular force). So I promptly went to the local big-box and bought some toggle bolts. Since I now had two brand-new holes, I only needed to slightly enlarge them to get the toggles through. That fixture hasn't moved since.
The toggles are your best bet because they

Distribute the weight of the anchor across a wider area
Would require the complete destruction of the drywall to pull out

Even the smallest toggles are rated far more than your fixture weight (a single 2" toggle is typically rated for 50-70lbs).
So what size do you need? Any size toggle will do, just be sure to check the size of the head. It should cover the hole on your fixture easily, but you might need a washer if the holes are large enough.
Comment: are you thinking 2 toggle bolts- one at each end of the fixture?  Any suggestion on the size of the toggle bolts?
Comment: Expanded my answer
Answer: I'd try for mounting into a joist. There's one joist that the box is mounted to, so might luck out and have one very close to where you want the lights and be able to put an eye screw into some wood. Otherwise, nothing wrong with toggle bolts or other similar drywall anchors that spread the weight over a small area.
Comment: I like the idea of fixing the fixture into a joist.  I need to mount the fixture flush with ceiling: should I do this with a drywall screw and not an eye screw?
Comment: Any kind of wood screw would suffice. The real question here is do you want to mount it parallel to the joist? If not, be prepared to drill through the fixture to make your own holes where the joists are. That's why I didn't suggest this method (and why you don't often see it done)


How do I figure out how much a share is worth in the PPLNS world?

Question: I'm trying to figure out how much accepted shares are worth, however small, in a mining pool, situation, specifically of a PPLNS scheme.  What is the formula to figure how what a specific share is worth?  I thought block reward might come into play, but since PPLNS isn't bounded by found blocks, I'm somewhat confused about how to start calculating.  I'm mining in this pool -- https://mixpools.org/xmr/ but use whatever pool as an example.
Answer: Shares are not equal. One persons "share" may have X difficulty and anthers has Y difficulty. Each share is associated the difficulty of an accepted hash. PPLNS favors miners that stay on one pool (as opposed to pool hopping) because the percentage of a found block payout is not just splitting on the hashes submitted for that particular block.
A good explanation of a specific implementation of PPLNS can be found here.


How do I unlock the "All Skills Learned" trophy after hitting Level 50?

Question: I'm level 50, but I only have 2 points to spend and 2 abilities left to unlock. Side quests only give XP so what now? Level 50 is the max level so XP from quests do nothing. In fact, I think I've completed all quests now. How am I supposed to unlock the other skills if I can't get any more Skill Points from leveling up?
Answer: The main quests as well as the Hunter Trials will award you Skill Points. If I remember correctly, main quests usually give you a Skill Point as a reward. Getting Blazing Suns on all 3 Hunter Trials at a Hunter Trial area will also award you a Skill Point. Additionally, completing Cauldrons and climbing Tallnecks will reward you Skill Points. If you haven't done all of these, you definitely should. From experience, I capped out my Skills by the mid-40s and was still receiving Skill Points from main quests and level ups, despite having nothing to spend them on.
By the end of the game, completing Hunter Trials and Main Quests should award you way more than the required number of Skill Points required to unlock all skills.
Comment: @Kev fun fact, there are no missable trophies in this game
Comment: Ahh ok thank's yes I haven't done the hunter trials yet so how many point's will I gain there? I need 4 more points. Thanks!
Comment: @Kev Each Hunter Trial area will give you one for getting blazing suns for all three trials at the locations. There are 5 Hunter Trial locationa (15 Trials total), so you'll get 5 Skill Points from those.
Comment: Thank you, I thought I'd messed up this trophy, time to hit the trials...
Comment: I actualy thought it was a bug with the game haha
Answer: There are other ways to receive skill points. Tallnecks, cauldrons, hunting trials, and main story quests all give skill points as well.
Answer: Collecting all the metal flowers, vantage points, vessels  and banuk figures each gives tons of skill points! At the time I found the last metal flower I had 5 Skill Points saved up. It jumped to 11 when I earned the flower trophy! They also jumped when I got the last ancient vessel, etc. Easiest way is to buy the maps locating the collectibles and bounce around campfire to campfire with Golden Fast Pack until you've got them all. I'm only at level 43 and I only have one skill left to unlock.


Does writing influence grammar?

Question: Do we know of any cases where the grammar of a language was influenced by the imperfection of its writing system? For example, has any language become isolating because it had a logographic writing, which didn't express inflections?
Comment: Interesting question. I guess there are cases where a "rule" of prestige language has changed the general grammar, and perhaps some of these might have come from oddities in the writing system. I can't think of an example, though, and it might be difficult to prove that that was the origin. I'm reminded also of the way that Japanese script constrained Japanese grammarians not to think in terms of consonant-final roots; but I'm not aware of any grammatical change that arose from this.
Comment: Hello Lev, welcome to Linguistics SE and nice question!
Comment: This might have affected some creole languages. Japanese is a case where it conspicuously *didn't* happen (they add *okurigana* after the logogram). Chinese might be an example, but probably hard to verify.
Comment: Creole languages? But most of them are not written! And I suppose none were written initially.
Comment: (1) Using a space had its influence (agglutinativeness of Finnish? CJK). (2) For the introduction of the orthodox christianity in the slavonic area, one started in Bulgarian with the invention of a new Cyrillic (glagolithic alphabet)[http://en.wikipedia.org/wiki/Glagolitic_alphabet], which was too complicated, and soon replaced by the current Cyrillic script. There are reciproke influences among Bulgarian and Cyrillic, but I doubt that the grammar is concerned. (3) The normal case of writing influencing the speech patterns: using "..., that ...", stilted talk, speeches.
Comment: Considering that when Late Archaic Chinese lost its morphology at a time when paper had not been invented and writing on bamboo was an expensive, time-consuming activity, it doesn't seem a priori likely that writing contributed to it as a main factor. Morphological differences that were reflected in writing (e.g. 言 vs 語) do seem to be better preserved than those which are not (e.g. 王 as a verb vs 王 as a noun), but there are a plenty of exceptions (e.g. 好 still has distinct readings).
Answer: This is really not the right question to ask. Writing is not just about the way of writing things down but also its own way of communication. People who read and write, don't just transfer speech into letters. They express themselves differently in the two modes. This is partly because of the different cognitive demands of reading/listening and partly because the two are used in different contexts. But in effect, all literate people are to an extent bilingual - they are competent in two codes and they switch between those codes with ease.
But as in all instances of language contact, there is cross-pollination. So it's quite likely that complex multi-clausal sentences with embedding and hypotaxis developed in complexity alongside writing - although I don't think there is any definitive proof of that. In some cases, written language perpetuates older forms - e.g. in Czech or Arabic that would probably otherwise disappear. In English, there are many pronunciations influenced by spelling and vice versa. None of these examples constitute 'imperfections', just features. Although, it would not be difficult to argue that the English spelling system is completely flawed, the impact of these flaws on spoken English has been minimal.
Answer: I don't know of any case of a particular script or orthography influencing grammar but writing in general can have an influence. Written forms of a language are very often their own "dialect" or register. Sentences tend to be longer and more grammatically complex. Undoubtedly this feeds back into the spoken language to some degree. But I guess this isn't the kind of answer you are looking for. I think it is more likely that grammar will influence the writing system.
Answer: No, Chinese characters or what we call Chinese logogram have not influenced it's grammar at all. Writing is just a image of the mapping from sound and maybe meaning of language. How could it influence the rule of language? From modern model of evolution of language like evolution game theory, also it is unlikely that logogram influences grammar either!

Does writing influence grammar?


UWSGI, Django, nginx cookie issue - causes 405 Error

Question: I'm running django via uwsgi and nginx, and whenever my app tries to set a cookie, nginx displays a 405 error. The app works fine with apache, runserver or gunicorn, and uwsgi serves it normally except for the redirect problem.
I'm running uwsgi like so:
uwsgi --master --http-socket :8082 \
      --wsgi-file /var/django/mysite/apache/live.wsgi \
      --touch-reload /var/django/mysite/apache/live.wsgi

My live.wsgi file looks like this:
import os, sys

PROJECT_ROOT = '/var/django/mysite/'

directory = os.path.join(PROJECT_ROOT, 'src')
if not directory in sys.path:
    sys.path.insert(0, directory)

os.environ['DJANGO_SETTINGS_MODULE'] = 'project.settings'

import django.core.handlers.wsgi

application = django.core.handlers.wsgi.WSGIHandler()

nginx is proxying requests to 127.0.0.1:8082 for this site.
UPDATE: Bizarrely, the issue seems to be triggered by django's messages framework - removing django.contrib.messages.middleware.MessageMiddleware stops the error. This leads me to think that it's got nothing to do with redirects after all, and is instead something to do with the message that's created on object save in the django admin.
UPDATE 2: Some further digging reveals that it seems to be an issue with cookies being set - switching the messages framework to use the session backend stops the errors. I'm still at a loss as to why the uwsgi/nginx stack won't let django set cookies. I've updated the question to reflect that.
Answer: Ok, so it looks like increasing uwsgi buffer size to 16k has stopped the errors. I guess the django messages cookie is too large? I'm not sure which solution is best out of switching to session storage or increasing the buffer, but there you go.
My uwsgi command now looks like this:
uwsgi --master --http-socket :8082 \
      --wsgi-file /var/django/mysite/apache/live.wsgi \
      --touch-reload /var/django/mysite/apache/live.wsgi \
      --buffer-size 16384

According to the django messages docs,

Old messages are dropped if the cookie data size would exceed 4096 bytes.

So I guess it makes sense that the uwsgi buffer needs to be greater than this.


Are black holes expected to contain the same ratio of dark matter to regular matter as the rest of the universe?

Question: Are black holes expected to contain the same ratio of dark matter to regular matter as the rest of the universe? I've heard that dark matter is distributed in halos around galaxies. Does that make it less likely to be ingested into a black hole?
Comment: Probably not, cause regular matter forms a neat accretion disk and dark matter (to my knowledge) does not.   The Milky way is 88% dark matter but the solar system is 99.999999999% regular matter.     One clumps, the other doesn't.    But, I'll let someone smarter than me answer this one with a reference to a real scientific stud or estimate.    I will add that there might be some uncertainty on primordial black holes and how much dark matter went into their formation.   Stellar black holes are made up of essentially all regular matter
Comment: @userLTK  I might modify your comment to read "all current observed effects indicate that darkmatter is uniformly distributed"  and so on, just to emphasize that right now we know diddly-squat about dark matter.
Comment: @CarlWitthoft - that's a good point.    It was probably a bad comment anyway cause it's an answer, but I was hoping someone smarter than me would give an official answer then I'll delete the comment.     And, Jospeh - yes, it's likely that dark matter gets eaten by and can't escape black holes but until we know what it is, I don't think anyone can say with certainty.   Dark matter is affected by gravity,
Comment: But we do think that black holes CAN hold dark matter, correct? Dark matter is still affected by gravity, if nothing else right?
Answer: (Short answer: No, scroll to the last point.)

It is irrelevant to an external observer whether the matter that fell into the black hole was dark matter or baryonic, by the no hair theorem. The only properties of a black hole from our point of view are mass, electric charge and angular momentum. (But of course we don't understand quantum gravity.)
From the point of view of matter which has fallen into the black hole, nothing special happens upon crossing the event horizon. This means that dark matter stays dark and baryonic matter stays baryonic when viewed from inside the black hole.
There is some controversy about how much dark matter exists in the universe. This recent article, for example, indicates in the abstract that more accurate modelling of galactic rotation curves could eliminate a large percentage of the expected non-baryonic dark matter. (Note as @pela indicated in the comments, that this author's papers have not been peer reviewed and could be suspect.) Obviously, the amount of dark matter in the universe would greatly affect the question's answer. I should note that the controversy is mostly composed of a small number of vocal scientists who appear disproportionately in the media. Following the mainstream news science sections, I get the impression that the death of dark matter seems to be announced once a month or so.
The formation of supermassive black holes is poorly understood. One hypothesis is that they may form by successive merger of stellar mass black holes. As there have recently been gravitational wave observations of such mergers, and as candidates for intermediate mass black holes have also been observed recently, I will assume here that this is how they form and that supermassive black holes are therefore made of roughly the same stuff as stellar mass black holes.
Black holes lose most of their mass during the formation process. It is important to always keep in mind whether we are talking about the mass of the stellar core which collapsed to form the black hole (this is often the "mass" of a black hole that is referred to when speaking about e.g. the minimum size black hole that can form from core collapse) or the mass of the black hole as seen by a distant observer after the supernova.
Dark matter particles can not lose much orbital energy by interacting with other matter nor by radiation, therefore will remain in orbit around a black hole rather than falling in, unless they happen by unlikely chance to hit it near the event horizon. This paper indicates that simulated supermassive black holes derive no more than about 10% of their mass from dark matter.

However, it must be said that some scientists suspect that dark matter is made of primordial black holes in the first place. There is also the theory of MACHOs (Massive Compact Halo Objects), that dark matter is composed of large compact bodies such as black holes, but it is believed by most that this theory can not account for the dark matter in the universe.
Comment: Just a small point, but "happen by chance to hit square on", while generally correct, probably isn't 100% right.    All massive particles that fly inside 3 radii are destined to fall into the black hole unless an outside force acts on them.  They don't have to hit directly just within 3 radii or 2 radii from the event horizon.  (I think its 3x, sometimes I read 1.5x).   Dark matter should be governed by relativistic effects, so there is a capture region outside the event horizon even if the dark matter doesn't lose any orbital energy by collision.
Comment: Nice answer, but the first paper you link to (Xiaochun & Kuan 2009) I'm a bit suspicious about. It is non-refereed, as is _all_ of Xiaochun's other papers. But as far as I can see from browsing very quickly through it, it actually seems to roughly _confirm_ the accepted dark-to-baryonic matter ratio. I don't think there's much controversy about the amount of DM (unless you're a MONDer). Also, note that your last comment is about _primordial_ black holes, i.e. whatever they're made of is a negligible part of the full-grown BH. But maybe that's what you mean by "in the first place". Anyway, +1.
Comment: Also, to expand a bit on @userLTK's comment: The 1.5 Schwarzschild radii ($R_\mathrm{S}$) is the "photon sphere", inside which all incoming objects will spiral into the black hole (they could still escape before they reach 1 $R_\mathrm{S}$ if actively "trying to"; e.g. a flashlight crossing $1.5R_\mathrm{S}$ will spiral in, but could still shine light outwards from the BH that could escape). The $3R_\mathrm{S}$ is the "innermost stable orbit", inside which an arbitrarily small perturbation will cause the object to spiral in.
Comment: I agree absolutely with @userLTK. By hitting the black hole "square on" I did not intend to refer to hitting the event horizon exactly, rather I intended it as seen from afar; that there is a small target region near the centre that they must hit. I'll try to make the answer a little more clear.
Comment: @pela Thanks for your feedback on Xiaochun & Kuan's paper. I must admit I did not check it up in enough detail. I'll also update the answer based on your feedback.
Answer: Dark matter is (thought to be) in halos which extend both to the centers of galaxies and outside most of the normal matter in galaxies (gas, stars, dust). So a black hole inside a galaxy could and undoubtedly will ingest some dark matter. However:
Stellar-mass black holes form from the core-collapse of a massive star. Since stars are almost entirely of regular matter, the initially formed BH remnant would itself have been made almost entirely of regular matter. Such BHs might later grow by accreting gas (e.g., from a close binary companion star), in which case they're gaining mass in the form of regular matter. There would inevitably be some dark matter swallowed by the BH as it orbited within its parent galaxy -- just as the BH would swallow some interstellar dust, for example. But it would still be overwhelmingly formed out of regular matter.
Supermassive black holes in galaxy centers would probably start out from some kind of early-universe collapse of a gas cloud or very massive star, which would again be mostly regular matter. Subsequent growth of supermassive BHs comes primarily from interstellar gas feeding an accretion disk around the BH, plus the occasional star that wanders too close -- so once again it's mostly regular matter that falls in the black hole. (The central regions of galaxies do have some dark matter, but they're dominated by regular matter. Plus, regular matter in the form of gas clouds can easily lose energy via cloud-cloud collisions and sink to the center of the galaxy, where it could feed a supermassive BH; dark matter can't do this.)
(Of course, as user25972 points out, it's largely irrelevant to outsiders like us what kind of matter goes into making a BH. A black hole formed out of dark matter would behave identically to one formed out of regular matter.)
Comment: Regular matter in the form of e.g. gas clouds can collide and lose energy and angular momentum, so that the gas will end up on smaller orbits closer to the center of the (proto-)galaxy. Gas clouds are also supported against self-gravity by internal pressure, which depends on (among other things) temperature; since gas can cool by radiation, gas clouds can end up with lower pressure and thus collapse to form clumps and stars.
Comment: So the answer in a sense is: dark matter and regular matter started out with similar distributions (and collapsed to form halos in the early universe); but regular matter in the form of gas can lose orbital energy and thus collapse *further* in ways dark matter can't.
Comment: Do we know why when the galaxy formed the dark matter didn't get distributed similarly to the regular matter? Why is it out there in halos? Shouldn't gravity pull it in like normal matter into clumps and stars, etc.?


Can databases alone host a hack?

Question: I was hacked recently. The hack seems to redirect any site on my server to a fake virus site. So I deleted all my website files and the hack seemed to go away. About a week later, it's back -- the same one. I never deleted my databases, but also never uploaded the websites that used them. Is it possible for the databases alone, without any website linked to them, to be somehow supporting the hack?
Answer: did you actually found and protected yourself against cause of the attack [ eg hole in cms / forum / whatever other webapp you had ]?
probably hacker left backdoor on your system for her/him-self and it's on lower level then web application.
regarding your question - yes and no - it all depends what kind of information is kept in the DB. if you have some scripted webapp that stores [ for some reason ] executable code [ eg plugins code ] in the database - then surly some backdoor could be left there. even if that is not the case - mabye you have templates stored in db - then for instance xss attack could be repeated against you even if you restored everything else.
Answer: A database SERVER can host a hack, or a database can too, if the database server is set to execute something (like a procedure/script in the DB).
In truth, anything that can execute code and has some (tiny) memory space can host a hack.  There have been cases of people hacking networks via a postscript printer, since postscript is a turing-complete language.
In your case though, it sounds to me like something much more commonplace is going on than a database hack.  Don't just delete files on your site -- that's just deleting evidence of the crime.  It's like sweeping away the bodies of friends when someone shoots them, and expecting no more freinds to get shot.  What you have to do is look at the bodies, question who they are, how where they killed, who would want to kill them, how did they do it, and how you can stop them.
You'll need to examine any web scripts you're using.  Learn about web security and check any code you wrote is secure; learn about the webapps you've installed, and check you have the latest versions, and that new versions come out whenever security problems are reported.  If new versions don't come out to fix problems, then delete the app and NEVER install it again; find a better alternative.
Also, make sure your operating system is up to date (windows update etc.), that you have antivirus installed and up to date, a working, properly configured, secure, up to date firewall, etc.
Answer: To add to what others have said already.  The DB can 'host' an hack but it's probably more likely that the OS is infected and not your DB.
Generally speaking however, once your host is infected, it's best to remove the server from the internet, forensically investigate the incident and rebuild the server, not just remove files and hope you got them all.
Answer: I think in order for anyone to answer your question accurately more information is needed.  Specifically, if one assumes you removed ALL websites from your server, the first question that springs to mind based on your database fears is: can your database server be reached over the Internet?
i.e. is it listening on a public IP?  A quick netstat -nuptl should give you this info.
Further, just taking your website content offline does not mean your webserver isn't still available, nor for that matter a host of other networked applications.  You need to be aware of everything your system is exposing on the network.
Also, as others have said, when you do not know where the intrusion came from, your best bet is to re-install from the bare metal up: OS, libraries, applications, services, etc.  Otherwise you'll spend valuable time running around looking for any possible exploit.
Once you've rebuilt using the latest patches for as much as is possible without causing dependency issues, strip out services not needed, or have them plugged into a Unix socket where possible, instead of a TCP one.  And seriously consider some form of IDS.  There are many available, but a simple one is AIDE, which works in the same manner as Tripwire - checking for file system changes against a database it compiles.
PS: Backup, backup, backup, and good luck.
Comment: Is [Sucuri](http://sucuri.net/ "Sucuri") similar to IDS? Is it a substitute? I use shared hosting, so I'm not sure I can use AIDE.
Comment: No, Sucuri is a service monitoring tool -- it tries to check that your public services are up and running correctly, to serve users.  It doesn't check whether your server has also been hacked and is doing other things, or is being prepared to do other things.  Nor will it catch all hacks of your public services, since it's checking for specific problems rather than checking for security compromises that can lead to any kind of problem.
Answer: In addition to pQd's answer:
Some database products allow to execute any system command using SQL functions (e. g. "system") if the user has sufficient privileges.
Answer: Is your only step to clean up your compromised system deleting the site files? You should change all passwords and restore from a known good backup.
Answer: You are talking about a crack as if it was a virus, than works from inside the system on it's own. There is a possibility that a virus was used to crack your site, but most likely it was cracked from the outside.
Restoring your website files only removed the result of the crack, not the security hole that allowed it to be done. That's why it could be repeated the next week, and that's why it will continue to happen until you fix it.
Two common ways of gaining access is through cross site scripting (XSS) and SQL injection. Both are possible when you don't encode text properly for where it's used.
If you don't HTML encode text that you write to the web page, a client script can be executed and gather information, like for example a cooke value authenticating your administrative login.
If you don't encode string values correctly when you create SQL queries, a value can alter your query to return a different result, or it can contain another query that can change data in your database.
Comment: -1 For Inaccuracy-  "Two common ways of gaining access is through cross site scripting (XXS)" First off, it is XSS, not XXS.  XSS is not a common way to gain access to a webserver--In fact, the three examples of XSS that is in the wikipedia article you linked to have nothing to do with gaining access to the server.  It is all about the client side-Yes, you could redirect a user to another site through XSS, but that is not the same as "gaining access to the webserver."
Comment: @Josh: I corrected the spelling error. I'm not sure what examples you are talking about, but obviously they are not represenatative to what's possible to do. You can read under "Exploit scenarios" for examples of information theft and hijacking.

Can databases alone host a hack?


Should I add a 'Home' Button to the navigation?

Question: I know that it is common behavior to have the logo of a web page be a link to the home page, but should I also have a 'home' link in the navigation bar for it as well?
Comment: I agree with some of the answers. I wanted to add that if Home is not provided, you could always include it on the top level on your breadcrumbs.
Answer: I don't know how many times (many) I've been asked "How do I get back to the home page?" when I've skipped the home link in the main navigation.
I've started doing 1 of 2 things recently:

Move the home link to the last or second last item on the main menu. I've wondered if this is a good idea because personally I often look for "Contact Us" in that position, but it seems to help users. But sometimes I will put it second last so at least it's there, but I could see this getting lost in the middle then.
Add a home image (small house shaped icon) somewhere in the upper portion of the page, usually on the right. The removes the need for an extra menu item.

I haven't had any complaints after doing either of these (that they can't get back to the home page).
I also think the general reason why people want to go back to the home page is because they get lost on a website, so I think reducing the cause is a better solution that encouraging people to "start over" to figure things out. This is unless your home page is like Facebook or SO where it contains the most recent information.
I do also like DisgruntledGoat's idea of doing something similar to Facebook's logo/home link with a roll over to show that it's the home page link.
Similar question and answers here: https://webmasters.stackexchange.com/questions/1649/
Comment: Your intuition about why people click a home link is fairly solid.  I observed a few usability tests for desktop and mobile sites.  We found that "home" was more of a panic button than something that drove the experience forward.
Answer: If there's room then I don't see a problem, but if your navigation is horizontal you don't want it overflowing into a second row.
Having said that, if you plan to expand your navigation later then removing the link at that point might confuse users.
It's not essential - if you notice there's no "home" link on the Stack Exchange layout as the site logo is the name and that's obviously clickable.
Comment: Well the Stack Exchange site mostly target a more experienced audience which are used to such navigation. For other audiences I think a 'Home' button helps with the navigation.
Comment: The Stack Exchange layout puts the logo next to the navigation menu. I'm sure that helps communicate the fact that it serves as the link to "home."
Comment: @Patrick - that's a good point, the logo is effectively part of the navigation.
Comment: @Gamlor - I take your point, it will be interesting to see with some of the more non technical Stack Exchange sites to see if it becomes a problem.
Answer: It's true that it is standard practice to have a click-able logo that returns home.  However, I have seen first hand that non-technical users have problems when this method is used exclusively.  Even when Home is on the breadcrumb.  For this reason I will always include a home link on the navbar.  People expect to see it.
Answer: I almost always add a Home link in the navigation.
Also users expect the logo to be clickable and to navigate to the home page.
Answer: I do also believe that this is completely on a "depends" basis. I mean, it depends on:

Whether the site logo (as a home page link) is obvious enough for users
Whether you have enough space on your nav bar, for a separate home link
Whether you are expecting so-called "noobs" (who may not be used to the logo being a link to home, as pointed out before) or a little bit more advanced users who are used to looking to the logo for the home link
Whether your site is large enough to warrant a duplicate home link

As a general rule of thumb, I would suggest that you do go ahead and have the logo be a link to home (obviously), and then go ahead and conduct some user tests to ascertain whether you need a separate link or not.
You may get all kinds of advice from people, professionals, books and so on, but until you conduct tests or get feedback after you have implemented whatever you have chosen, you will not know for sure which way is best.
Good luck.
 -b
Answer: One way might be to do as Facebook does (the ultimate example of a site designed for average web users in my opinion).
A few versions ago a small home icon would appear when you hover over the logo. This very quickly conveys what clicking on the logo will do without having to tell the user or to make it noticeable when the user might not been it (hence appear on hover).
What they do now though is have a very obvious hover effect (the background gets lighter) so the user can see that clicking the logo does something, however maybe not exactly what until they click it for the first time.
Maybe try something like the first situation.
Comment: Having a hover effect definitely improves the experience, it clearly shows that its a navigation element. The only problem is with touch screens because there's no hover behavior.
Comment: Very true, however I was assuming this was for a website for use on a normal computer. Maybe if you know a device is a touch screen you could add a small home icon next to the logo or make it so the hover effect is always on (in effect just always show the home icon).
Answer: I'd say that ultimately it depends on your userbase. A lot of mine for instance are reasonably uninitiated, so on our Intranet applications we still include it and also make the logo/header link back to the main page.
Breadcrumb or not, users need an obvious way of getting home and the best way to go about that would be to include a link in your navigation. That way, it's a little more intuitive for users of all abilities.
Answer: I often think about this question when I approach the main navigation for a site, and the answer will usually vary depending on the individual context. For example:
• How many items need to populate the main navigation; can we afford to add 'Home' without cluttering it?
• How web-savvy is the intended user-base of this site? Look at the personas - would they recognise a design pattern such as a site ID link? (If you're not still not sure, user testing is key)
• Does the site's logo design lend itself to being a clickable object? (It may be of a size, shape or visual contrast that doesn't make it easily recognisable by users as the site ID)
• How frequently do you see a user wanting to return to the home page, given the site's content?
• How 'deep' does the navigation go? How frequently do you see users needing a journey reset button?
• Is there important content on the home page that you can frequently seeing users going back for?
My advice is also to always include a clear breadcrumb. One thing that continues to surprise me in usability tests is the amount of people who regularly use the breadcrumb.
At the end of the day though, user testing should answer this question. If users are struggling to figure out how to return to the home page for lower level content, it might be time to add a link in the main navigation :-)
Answer: Personally I hate them.  I prefer the Stack Exchange approach of having the logo be the home page and close to the menu.  But, the best example of the logo being part of the menu is definately apple.com.
Some other examples:
Microsoft.com - no home link
Dell.com - no home link
Intel.com - no home link
Sony.com - no home link
HGTV.com - no home link (and a counter argument about StackExchange users being more sophisticated than other users)
Because I have to thrown in sites I love with Home links:
LinkedIn.com - home link
37signals.com & child sites - home link
I think when you view enough large sites you realize that their is a trend to let the logo be the home link for numerous reasons.
One reason I personally think is important and relevant is SEO - using the alt text for the logo is much more valuable than having home as anchor text for a link.  Having numerous links to the same content that early in the HTML can also have a negative effect.
While duplication of navigation can be very helpful - it can also eat up valuable whitespace or space for other navigation.
Answer: Don't forget that the Home page link is just a part of the information architecture. Having it in home page depends on the rest of it.
Eg. a better choice for this might be the breadcubms menu:
You are here: home -> category -> product
This works best as a reverse navigation, so the clickable logo with a hover effect should be enough in this case.


Why doesn't China negotiate trade deals with each state in US?

Question: Say, let each state send representatives to bid for import quota of specific categories of merchandises, therefore making intra-US cooperation among states into inter-state competition; just like how countries have trade deals with EU members while maintaining a relationship with EU.
Comment: Actually EU rules don't allow for trade deals with individual EU members. This is one of the main issues in the "brexit".
Answer: Under Article I, section 10 of the US Constitution, no state can enter into an agreement with a foreign power without the approval of Congress. No state can enter into a treaty with a foreign power period, even with Congressional approval. This is specifically to prevent what you're talking about: the US is a single country and is supposed to act as a single country on the international stage.
Answer: Legally binding agreements between the states are called Interstate Compacts. Creating them requires an act of Congress (Article 1, Section 10). Some are based on a model agreement, approved by Congress, that any state may join, such as the Driver License Agreement. Prior to the original Driver License Compact, it was not unknown for out-of-state drivers to be arrested for minor traffic offenses - because there was no way to ensure that the traffic violator could be held accountable when they left the state. The remainder have to be submitted to Congress for approval and ratification (for example, the New York Port Authority was approved by Congress in 1921). The only compact that I am aware of, that includes parts of another nation, is the Great Lakes Charter, which  created the Great Lakes Compact governing water rights and water usage in and around the Great Lakes bordering USA and Canada.

Why doesn’t China negotiate trade deals with each state in US?