In quantum mechanics, there are many problems; the biggest of them (according to a group) is finding the first and initial state. We are talking about the initial state of the observable universe; it sounds cliche. But people believe that if we can find the initial state, we can determine the difference between the macroscopic and microscopic world. I have not any thoughts on that. However, as like many, my respect for quantum mechanics is just fundamental (and theoretical). When you do quantum mechanics, without any evidence of research, you will likely come to believe that 'what is true and what is wrong' is differently to be seen in the subject.

Just like the statistical mechanics, we have $\rho$ the density matrix in quantum mechanics. This looks like

When we come to 'Copenhagen's Interpretation of quantum mechanics, which is heavily misguided in different ideologies, we can observe incompleteness and loss of determinism. The former and latter can be written to co-exist as 'no macroscopic evidence.' It is not entirely true. However, it is accepted that the interpretations can be completed by the completeness of matching the probabilistic theory to macroscopic lurches of evidence. Indeed, we would enjoy a version like this. Rather than this, the Copenhagen interpretation is widely celebrated as a successful interpretation.

_____________________

The reason these are half-baked problems that no one now cares about it. These problems are widely accepted as 'reality and fundamental.' Even when young people try to think about it, they fall into the prey of 'cancellation' and 'no go' which they say are occults of the subject. But, my stance is quantum mechanics is an achievement that we should sing from time to time.

Notes; A friend of mine shared with me an unlisted link of a talk by Weinberg at 'Standard Model at 50', in which he talks the same. And in fact, this post is inspired by his talk. 

https://www.youtube.com/watch?v=mBninatwq6k

Curiosity is a priceless yet costly character that one can achieve by abolishing many senseless predefined characters. It is a fundamental gift that everyone should receive, and better to accept it now, not any old. In history, it is beautifully depicted how impeccable a person can be with his curiosity and ability to find what can't be found.

You, at some point, will or already have realized that being idle is also a curiosity. Not virtuous, yet you are finding, not consciously, the results for being nothing. That, however, never promotes you to do "nothing." 

Curiosity drives more than it stops. 

My cabinet couldn't afford fancy and expensive collections but was a pure collection of paintings, some books I considered worthy, some notebooks, and a book on 'F=ma.' I am sure the last piece in my anachronistic chronology was pure gold (Hawking's small books), at least when I was 8 or 9. My cabinet also had a book on Geometry; I still have that,

But what constitutes a perfect cabinet of curiosity? I don't know, but I guess in ancient times, or perhaps medieval, when kings and connoisseurs were making their cabinets, they included many precious things in them. We can't imagine even finding some of them now as they were exquisite in that period. I recommend you read some articles and books on it. Kings of those times were likely to build one hall or building to showcase what they had. Now, what they had is a different matter, but what to emphasize is that we have lost its culture. Though people, often academians, build a library that contains only books. I know some people who like to collect paintings, and their house is just paintings by artists like Van Gogh. I haven't seen any theatre of curiosity, and I hope to see it soon.

Curiosity is different for different persons. It pushes us to know what we can't, and I assume many have this definition in their books. However, some believe it to be a pause for us to stop searching. Curiosity doesn't mean you have to find what is to be found; you have to find what you want to find, which is the classic definition. Some doubt, in philosophy, how much curiosity is good. I have no idea; curiosity is not an entity of quantity, so how can we put an upper or lower bound on it? Curiosity is nothing if tied to the environment, and hence environment is the key to the 'subject' for defining what lies beyond curiosity.

An important thing to note is that there is a sentence in literature, "curiosity killed the cat," so we better not pry much and call it curiosity. Some works can be done without curiosity, and some need them badly. Science falls in the latter category.

 People are often heard whispering "Tit for Tat", but reciprocally. Yet, what is the game theory behind Tit for Tat (TFT)? For that, what is TFT? 

TFT is the usual game for two/more individuals or two/more groups. It starts with a situation where one of the teams is given a chance to first act. This act can be of two types, either defection or cooperation. Then the second player acts according to the previous move. The most classic and well-known example is Chess. When white moves its piece, the black always makes a move according to the first. But this is not always right. In chess, if a move doesn't concern you much, you can follow your lead using your strategy without being in a situation where you have to act accordingly. 

However, there is one fascinating game theory called the Prisoner's Dilemma, which uses TFT (and its extensions) very much. It is intricate at first but self-realizing after you allow the logic to play itself. Merrill Flood and Melvin Dresher were the first ones to realise this game. Afterwards, Robert Axelrod influenced this game theory.

Prisoner's Dilemma is a situation concerning the two criminals who are arrested. Let's say A and B are criminals. Just for the sake of game theory, we give both the criminals a chance to get free from charges. Conditions are that A and B are given two choices. These choices are imagined on a ground where both are standing with each other. The options are to either defect/betray the opponent or remain silent. The catch is, they are not allowed to talk or get informed about one another. Rules are as follows,

• If A betrays B, and B betrays A, both will be charged with two years of the sentence.
• If A betrays B and B remains silent. Then A will get free, and B will be charged for three years.
• If B betrays A and A remains silent. Then B will get free, and A will be charged for three years.
• If neither A nor B defects each other, they get only one year of charge.