Why is the US so politically right-wing?

Question: Bernie Sanders is called "radical socialist" or even "communist" in America but in Europe, as I understand it, he would be considered a center-left or even centrist politician. Europe also participated in the Cold War against the Soviet socialist regime, but they managed not to develop a strong aversion to anything that involves higher taxes, more regulation, free healthcare (or state-run and, therefore, cheaper healthcare), etc. For example, in the UK, the Tories not only don't call NHS "radical left socialism", but they are instead pretty vociferous in their demands to fund it more (including by diverting EU-bound £350m —  at least, according to the Brexit campaign's not-entirely-accurate allegation; the campaign was spearheaded, in large part, by now-prime minister from the Conservative Party Boris Johnson). How come?
Comment: One could just as well ask "Why is Europe so politically left-wing?"
Comment: I downvoted this question because of its structure, and it is likely addressed elsewhere. The political spectrum of the US, as it exists in the entirity of the possible political ideologies, is neither parallel or adjacent to the political spectrum of Europe. While there is some intersection, the focal point of the US spectrum is bound by the where individual rights stem from and how government obtains and uses its authority.
Comment: Why has my question been downvoted so badly?
Comment: @SergeyZolotarev I don't see anything wrong with the question (except maybe being a duplicate, but I haven't checked). But given the opposition you're facing here, you might have a better chance at getting a decent answer at History.SE, because the origins of this divide are largely historical.
Comment: https://scholar.harvard.edu/files/alesina/files/423__0332-alesina11.pdf
Comment: I don't really think this link is worth an answer, so it just becomes a comment: https://slate.com/business/2019/01/scandinavian-socialism-might-be-a-product-of-19th-century-us-immigration.html I also think some of the historical analysis in Pikkety Capital in the Twenty-First Century offer good historical analysis on the subject
Comment: I'm not sure how the Democrats fare these days relative to the European left (because both are in a fair bit of flux), but regarding the right-wing, see https://politics.stackexchange.com/questions/47147/on-what-dimensions-does-the-current-republican-party-differ-substantially-from-t although no answers have been posted insofar.
Comment: @DrunkCynic Pretty much everything is addressed elsewhere, otherwise it would take original research to answer a question.
Answer: (This answer assumes right-wing as in: individualist / small-government / pro-business, not right-wing as in authoritarian or royalist)
This has to do with the history of the USA.  A complete answer would take an entire book, so this answer is not complete, but two important contributing factors for Americans with a protestant white European migration history are:
Manifest destiny
Manifest destiny has contributed to a culture of individualism in the USA.  For much of US history, immigrants were getting free plots of land in the west.  It was up to them to build a house and defend themselves against any natives who might disagree on who has the right to use this land.  People very much depended on themselves only, and may view the government as being in the way rather than being a source of help.  Much of the Mid-Western United States was settled this way, and rural areas here remain very much Republican Party strongholds.
Compare this to Canada, where the Royal Canadian Mounted Police (RCMP), or mounties, would go ahead and pacify areas ahead of migrants settling there.  It may have been considered more civil, but was certainly a more collective approach.  You'll notice that politically, Canada is in some ways more like European countries than like the USA.  They still have a Queen too.
The social-democratic, socialist, or communist  movement is inherently collective in nature, and based on the idea (I'm oversimplifying here) that the rich are exploiting the poor.  When you have tenant farmers or factory workers, the idea that the rich are exploiting the poor has a good audience (and perhaps indeed some truth), in particular if the rich were born rich and powerful.  In Europe, the nobility was still holding most of the power until the early 20th century, when revolutions in some countries and reforms in others took away most of their formal powers.  In America, such nobility does not historically exist in the same form.  (I don't know how it was in Canada).  That's not to say classes don't exist, but the cultural perception is that there is more social mobility, and this was probably true for white men before European countries became democracies and established their welfare states.  When the cultural perception is one of more social mobility, people may consider that people who are rich have deserved it.  Even many poor Americans still embrace this idea today and have therefore been much less susceptible of leftist ideas.
You'll also find that the cities are more left-wing than rural areas.  Although this is partially (but not universally) true in Europe too, I think it's stronger in the US.
A religious refuge
Until the early 20th century or so, the USA had a greater freedom of religion than Europe.  Many Europeans with religious views that were out of the norms moved to the USA, because they felt they could practice their interpretation of religion there in more freedom.  People who are deeply religious are often less susceptible to socialist and communist ideas; Marx was quite critical of (organised) religion, and churches have historically often preached against left-wing movements.  Marxists will say this is a ploy to keep people ignorant and prevent them from rising up against their oppressors, but either way, it means left-wing movements have less of a chance.  There are still religious conservatives moving to the USA today, because it offers more homeschooling opportunities than many European countries, and for religious reasons, they want to teach their children themselves rather than to subject them to the public education system (where they may be exposed to ideas that the parents strongly disapprove of).
McCathryism and the Red Scare
This was mentioned by Italian Philosophers 4 Monica in a comment.

Propaganda poster, New York Evening Telegram, 1919.
From the Communist Revolution until well after World War II, anti-communism was a strong force in the USA.  This was not limited to combating actual communists, but a lot of less radical left-wing movements were accused of communism at all.  Even today, people who are not at all communists are accused of communism (example one, example two).  To what degree this is cause and to what degree effect of the US being politically right-wing I'm not sure, but it may well be both.

Americans with a different migration history than the White Anglo-Saxon Protestant (WASP) Euro-Americans are not nearly as right-wing.  People with a migration path via Latin-America (Hispanic Americans), or with ancestors in Africa (African Americans, often with a history of slavery) are much more likely to vote for the Democratic Party, which currently hosts political ideas to the left compared to the Republican Party (many of them also migrated well after the Red Scare was at its height).  Native Americans also largely vote for the Democratic Party, but they are too small in number to be an important political factor nationally.  I'm less sure about Asian-Americans but I believe those are largely urban anyway.  The trend of minorities more likely voting Democrat is so strong that some describe the Democratic Party as one of minorities.
(The question can be asked how left-wing the Democratic Party is.  It's a different question.  It seems to me that although the mainstream Democratic Party of the last 20–30 years would be right-of-centre in most European countries, there are some representatives such as Alexandria Ocasio-Cortez whose political positions would be left-of-centre even in Europe; the electoral system of the USA favours a wider variety of opinions in the same party.  A similar trend can be seen in the UK, where everyone from Tony Blair to Derek Hatton) is in the same party)
Comment: Democratic Party is still too right by European standards.
Comment: @user28434 The Democratic Party has become what the British call a "broad tent".  It includes anything from pro-business billionaires to [Alekandria Ocasio-Cortez](https://en.wikipedia.org/wiki/Alexandria_Ocasio-Cortez#Political_positions), whose views are IMO not right-wing by European standards.  Edited to address this point in a parenthetical remark.
Comment: [In the last Presidential election](https://www.cnn.com/election/2016/results/exit-polls), the Democrat got 89% of the Black vote, 66% of the Latino vote, 65% of the Asian vote, 56% of the "other race" vote, and only 37% of the White vote.
Comment: Do you think, and that specifically regards to Communism, that one part of it is that during the post War period, the US was pursuing a policy of containment/suppression from afar whereas broadly speaking Europe, being the potential battleground, was more into finding a modus vivendi/coexistence?  Communism <> Socialism but what were more Communist Euro parties evolved/lost members to left/center-left parties, whereas the US never really tolerated really left wing parties from the 50s on, due to containment policies.
Comment: @gerrit BIG tent
Comment: @SergeyZolotarev You're right — I got confused between the terms "broad church" (used in UK politics) and "big tent" (used in US politics), which mean the same thing.
Comment: @dan04 Thanks for the data.  I suspect that some of that is explained by socio-economic class and urban location, but it's probably also cultural.  I strongly suspect this has been looked into in more detail, but that goes beyond the scope of this question.  I wonder what % of the NRA membership has European ancestry.
Comment: @gerrit: I couldn't find stats for NRA membership in particular, but I did find a Pew article for [The demographics of gun ownership in the U.S.](https://www.pewsocialtrends.org/2017/06/22/the-demographics-of-gun-ownership/)
Comment: @ItalianPhilosophers4Monica Good question. Maybe. I don't know if anti-left hysteria / McCarthyism is rather a consequence or rather a cause of the US being politically so right wing, or perhaps a bit of both.  It's also 70 years ago. I'll edit to address this.
Comment: This is an excellent answer, +1.
Answer: Disclaimer: This is my personal view from the outside (Germany). My only insight is the US news media, which I followed for a few years.
This is difficult to answer, but it all comes down to the two party system, necessitated by the electoral system of the US.
It is easy to say "no" to change and it's easy to get people to say "no", but it's difficult to enact change, because change is, emotionally, difficult to predict and scary, so political actors that are against change have significantly more power than those that push for change.
As an example, the NRA has one modus operandi: Get people to reject every gun law. No discourse or weighing of arguments, just a flat "no", whatever the law might be. There are many such direct or indirect political actors in the US which push for strict rejection of anything that interferes with their status quo. Those political actors are usually aligned closer to parts historically belonging to the republican party, e.g. the climate change deniers (Oil industry saying "no" to regulations), gun proponents (gun lobby saying "no" to gun laws) or trickle down economists (Rich people saying "no" to taxes on them).
This gave the republican party enough power to prevent change when they weren't in charge and enacting their own policies when they were in charge. While the democrats often push arguments, the republicans just as often push flat out rejection.
Those republicans that disagree with those "naysayers" still disagree with the democrats even more on other policy points, so they can't leave their party without leaving politics completely, because forming a new party is all but impossible with the electoral system as is, which forces them to cooperate with the naysayers, giving those even more weight.
This isn't to say that it's entirely the republicans fault. The democratic party does have naysayers as well, especially where party internal change is concerned. Democratic politicians that push for too much change, a reform of the democratic party or even a reform of the electoral system, which would potentially take power away from both established parties, are opposed by democrats that reject change. However, in the last 20-30 years the trend was consistent with democrats pushing for change and republicans rejecting it.
Comment: The electoral system in Canada, United Kingdom, or Australia is similar, and those countries have mostly 2–3 party systems, but are not nearly as right-wing. This answer does not explain why the US has developed differently from other countries with similar electoral systems.
Comment: @gerrit It's a combination of "The world is moving left" and "It's easier to prevent change than to enact it". If one party is focused on preventing change and has enough power to do so due to the electoral system, the country will be stagnant politically while all others move left and it will end up looking relatively more right wing than comparable countries. In other countries, either there isn't a single party capable of preventing change or there isn't one willing to do so.
Comment: Australia most definitely does *not* have a similar electoral system.  All voting is preferential (instant-runoff) and it is mandatory for all citizens to vote.  This drastically changes the political equation.
Comment: At least in the UK the electoral system is only superficially similar. While the UK also has a first-past-the-post system, there is no electoral college and votes for smaller parties have the chance to gain them seats in smaller constituencies, e.g. Sinn Féin in North Ireland, SNP in Scotland, etc., which allows them to have some amount of influence. New parties are not too uncommon (Brexit Party, UKIP). Arguably, though, the UK is sliding further right at the moment as well. I'm not informed enough to talk about Canadian or Australian politics.
Comment: US and UK both elect their parliaments by first-past-the-post, but the US two-party system became more entrenched than the UK one.  But I don't see how a two-party system necessarily leads to becoming more right-wing.
Comment: @Morfildur: Why would anyone think that the world is moving left, when pretty much all  Communist governments have collapsed, China mutated into a state capitalist system, &c?
Comment: @jamesqf: Because a lot of people conflate "the world" with "the Western world".
Comment: @dan04 I would say that the West has been moving to the right, not to the left. At least in Europe, the traditional center-left parties first moved to the right in the 90s (think Blair and others). Then the power shifted to the traditional center-right in the 2000s, and the 2010s saw the rise of right-wing populism and the decline of the traditional center-left.
Answer: I read an interesting article some years back (unfortunately I cannot locate it at the moment), which held that up until the early 20th century the US privileged economic adventurism: a semi-colonial expansion that took us across the western breadth of the nation, up to Alaska, and out to Hawaii, the Philippines, and other pacific island territories and protectorates. In this period the power of the government was more or less aligned with the interests of individualist capitalism: everything from homesteaders to gold miners to remote plantation owners. As people expanded outward to exploit new resources in comparatively untouched lands, the US army and navy would follow to secure the land, suppress native populations, and guarantee a comparatively safe environment for commercial extraction. However, at the time of the Great Depression the US Government shifted focus. Instead of supporting economic adventurism — which was (after all) complicit in creating the great depression, and which in any case was running out of new territories to expand into — it turned to public assistance and support for people who were not property owners or adventure capitalists, implementing the 'socialist' policies of the New Deal and eventually other 'liberal' institutions.
This shift fostered the political divide we see today. On one side we have 'Rightists' who still follow the capitalist 'colonial adventurism' paradigm. This is a competitive model in which people who fail to secure or use property have no one to blame but themselves, and are undeserving of public assistance; as Weber pointed out, this is aligned with the Protestant (Calvinist) presumption that material success correlates with moral worth, and poverty with moral depravity. Immigrants, indigenous peoples, ethnic minorities, and lower-class laborers are all considered necessary evils: useful for immediate productive purposes, perhaps, but dispensable at the end of their usefulness, and decidedly not qualified to engage in public affairs.
On the other side are the 'Leftists', who see the US as an inclusive multicultural melting pot, and generally object to monopolistic, exploitive economic practices that harm one class of people for the exclusive benefit of another class. Even in the 19th century this group showed up as abolitionists, social reformers, and the like, but by the time of the New Deal they had crystalized as what we would call these days 'social democrats', a blend of liberal and Marxist thinking that emphasized universal rights, broad suffrage, fair wages, social safety nets, judicial and criminal reforms, and other guarantees that individuals are not deprived of certain basic rights merely be cause of social class or wealth.
The exact nature of this divide has shifted over the decades: the Right has moved through segregationism, McCarthyism, masculinism, and the militia mindset to the modern anti-immigrant, anti-islamist standard; the Left moved through civil rights, feminism, gay rights to the general progressive focus on a fair political playing field we see forming today. But the divide has  always been a matter of governmental priorities — a dispute over how and to whom government funds should be allocated — and because of a variety of factors has become increasingly polarized.
The impression that the US is 'Rightist' is more a factor of this polarization than a factual reality. Polls consistently show that Americans are largely in favor of many slightly-left-of-center policies; there is broad support in the populace for universal health care, gay marriage, reasonable immigration policies, etc. The US is a bit to the right of Europe because the US has a much stronger Christian community, and religious communities tend to be more socially conservative. But the difference is not as significant as it might seem from listening to US political figures. US politics has been dominated in recent years by people eon the far right of the spectrum, beginning with the creation of FOX News back in the Clinton era and coming to a head with the election of Obama in 2008.
Sanders is a particular target for this 'economic adventurism' Right because he explicitly and openly endorses socialist policies. Even granting that Sander's brand of democratic socialism is milquetoast by European standards — Marxists would see him as a liberal democrat with pretensions to socialist thought — the Right has spent decades vilifying and demonizing socialism in order to shift government policy back to their worldview, and Sanders presents an in-your-face challenge to that news-cycle hegemony. Even the DNC is worried about this, mind you, because that knee-jerk McCarthyist reaction is going to cause some bad optics, and they are not sure they can spin it in their favor. But in any case, I would take this reaction to Sanders less as a reflection of the views of the US populace than as a comment on this long-term, polarized divide among political influencers.
Answer: Established parties are more likely to be conservative than radical. If a system works, conservatives do not like to tear it down for ideological reasons. An European right-wing party may oppose free education and public healthcare for ideological reasons while simultaneously supporting them for practical reasons. US democrats may like free education and public healthcare in principle, but they do not actively advocate for them, because the existing system already works. Because the parties are conservative and operate in different environments, it is difficult to say which of them is further to the right.
(Europe has things like free education and public healthcare largely for historical reasons. Revolutionary communists had mainstream appeal, and supporting the demands of the moderate left was seen as a good way to make communism less popular.)
European left-wing parties rarely enjoy majority support (even if we include green parties with the left), while US democrats often do. Democrats often try to appeal to centrist voters in order to win first-past-the-post elections. For these reasons alone, the Democratic Party would not be a left-wing party by European standards, even if there were no fundamental differences between European and US voters.
Voter turnout is another major difference. Highly educated wealthy people are more likely vote than those with low incomes and little education. Politics in countries with low voter turnouts are more likely to be skewed towards the interests of the well-off. In the US, the turnout is usually ~60% in presidential elections and ~40% in midterm elections, while many European countries frequently see 70%, 80%, or even 90% turnouts.
As for Sanders, calling him a radical socialist is appropriate. He is a socialist according to the US usage of the word, he calls himself a socialist, and he certainly advocates for radical changes in the society.
Comment: Re *"radical"*: through technology alone, the US and the world are undergoing radical changes.  No leader could stop the clock on tech; so it's not a question of *if* what a candidate advocates is "radical", (as virtually *any* policy would be nowadays), but rather whether their policies and skills can safely direct the ship of state in these stormy and interesting times.
Answer: A "trick" theory-answer:  perhaps the US is not that politically right-wing, and is, (relative to appearances), more moderate and left wing, but its wealthy conservative elites labor mightily at pretending to make it seem as though the US were right-wing, via quite excellent propaganda disseminated by their majority share of the mass media, as well as longstanding and shameful methods of disenfranchisement and voter suppression.
As to why the US's wealthy conservative elites choose to live this way, perhaps it's because that's how prior generations of wealthy conservatives behaved, and those ruthless traditions are all they believe they can trust.
Comment: (Certainly if the majority of the US *were* right wing, they'd have little need for, or patience with, disenfranchisement, gerrymandering, voter suppression, a tie-breaking partisan judiciary, *et al*, since a significantly more popular party could easily win without without resorting to underhanded strategems.)


Linux - encrypt file system

Question: How do I encrypt file system on Linux (/).
I know, how to do that on fresh installation, but how to achieve same, when Linux is already installed?
Can i move everything from main partition to secondary (which is encrypted) and somehow change / mount point?
Answer:
Can i move everything from main partition to secondary (which is encrypted) and somehow change / mount point?

Yes, you can.
Essentially it is the same process as moving a Linux install to a new disk/partition, only the new partition is encrypted.
See e.g. How do I move a Linux installation between partitions?
Only caveat: As the new system needs to boot from an encrypted /, you need an additional, unencrypted /boot so the system can boot. Also, the boot scripts need to support this configuration; current Debian/Ubuntu already does.
Edit: BTW, though this should go without saying, make sure you have a working and current backup before doing this.
Answer: Unsure if you would be willing to use a third party program to do this but if you are True Crypt is available for linux and is pretty good at encrypting the system drive.  I have done so on numerous laptops here at work and use it on a multi boot system at home.  They have just released a new version as well which I believe can spped up the encryption time as well.

Linux - encrypt file system


How does the cell cycle affect stem cell fate?

Question: I keep reading about the stages of the cell cycle affecting stem cell fate, however I do not understand how. After all, any cell will have to pass through the whole of the cell cycle, and go through every state.
Answer: If you are referring to cells that are differentiated in adults:
Some somatic cells in multi-cellular organisms are post-mitotic, that is, the cells cannot divide, or said in other words, they don't enter in S phase. This cells are said to be in G0 phase, because they keep synthesizing proteins but the won't replicate their DNA.
Another thing we could say about cell cycle having something to do with cell division, is that in G1 and G2 (and , of course in G0) different cell types, produce different proteins. ie: a skeletal muscle cell, produces lots of proteins associated with the contraction, but neurons not so much.
If you are referring to the first cell divisions in a multi-cellular organism's development, then:
in cleavage, the cells are dividing synchronously, and they avoid some cell cycle stages, like g1 or g2 (in cleavage, the cells are just dividing and replicating their DNA; the protein synthesis happens with mRNA inherited from the mother). In this stage, there is no cell growth at all. After some cell divisions, they have to start synthesize mRNA  and, because of that, they start to divide asynchronously. Eventually the cells (for this and also for many other reasons) get differentiated.
I hope this answer is useful :)


What will happen to the people who disregarded all the prophets' miracles as magic?

Question: We know that many prophets performed miracles and many people didn't believe these prophets because they thought it was all magic. But will Allah punish these people? Why would Allah punish them in the afterlife? In the Quran, Allah says that he will not charge a soul beyond it's capability. So if a person is not capable of distinguishing between miracle and magic, why should Allah punish him? It just means that Allah needs to show a stronger sign.
Answer: It is commonly quoted in the Quran that disbelievers called many of the miracles of the prophets magic. To mention some of the verses:

So when there came to them (Pharaoh and his people) the truth from Us, they said, "Indeed, this is obvious magic." (10:76)

And [even] if We opened to them a gate from the heaven and they continued therein to ascend, They would say, "Our eyes have only been dazzled. Rather, we are a people affected by magic." (15:14-15)

The Hour has come near, and the moon has split [in two]. And if they see a miracle, they turn away and say, "Passing magic."  (54:1-2)

(More verses: 6:7, 10:2, 26:34, 27:13, 28:36, 34:43, etc.)
It is clear reading all the verses about it, that those who make this claim are disbelievers. The punishment and end of disbelievers is well-explained in the Quran and Sunnah.
There are some valid questions one may ask. Someone may ask: If someone believes in magic, how should he know the difference between a miracle and magic? Why would he be punished for denying a messenger that could be doing magic?
The answer: Messengers are chosen from those who have lived with their people for long, and their people know them very well. For example, the Prophet Muhammad (SAW) lived with his people forty years, he was well-known for his honesty and integrity, and his life was not a secret.
Ar-Razi mentions in his tafsir about 10:2 where the people of Makkah accuse the Quran of being magic ([But] the disbelievers say, "Indeed, this is an obvious magician"):

واعْلَمْ أنَّ هَذا الكَلامَ لَمّا كانَ في غايَةِ الفَسادِ لَمْ يُذْكَرْ جَوابُهُ، وإنَّما قُلْنا: إنَّهُ في غايَةِ الفَسادِ؛ لِأنَّهُ ﷺ كانَ مِنهم، ونَشَأ بَيْنَهم، وما غابَ عَنْهم، وما خالَطَ أحَدًا سِواهم، وما كانَ مَكَّةُ بَلْدَةَ العُلَماءِ والأذْكِياءِ حَتّى يُقالَ: إنَّهُ تَعَلَّمَ السِّحْرَ أوْ تَعَلَّمَ العُلُومَ الكَثِيرَةَ مِنهم فَقَدَرَ عَلى الإتْيانِ بِمِثْلِ هَذا القُرْآنِ. وإذا كانَ الأمْرُ كَذَلِكَ كانَ حَمْلُ القُرْآنِ عَلى السِّحْرِ كَلامًا في غايَةِ الفَسادِ، فَلِهَذا السَّبَبِ تُرِكَ جَوابُهُ.
Know that, because this statement is the height of nonsense, its answer is not mentioned. We just say: It is nonsense; because the Prophet (SAW) was from them, he grow up with them, he was never absent from them, and he did not collaborate with people other than them. And Makkah was not a land of scholars or intelligent people so that they might say "He learned magic from them" or "He learned many sciences from them until he was able to bring something like the Quran." When the matter is like this, calling the Quran magic is the height of nonsense, and because of this there was no explicit answer given in the verse.

So, it is a catch-22 for the disbelievers that claim his miracles are magic.
If the miracles are magic, how did he supposedly get so good at magic overnight? If he did do so, that is itself a miracle and a sign that he is being supported by God.
If the miracles are not magic, they have returned to our position.
So, even if the person claims the miracles are magic, after knowing that this man has lived with them for many years, never learned magic, and never lied before in his life, there is no way of denying the message is from God.
If someone accuses the miracles of being magic and also not from God he is simply being stubborn and going against logical and rational realities. At that point, let him go to Jahannam and think it is magic too. No proof that it is from God either right?

The Day they are thrust toward the fire of Hell with a [violent] thrust, [its angels will say],  "This is the Fire which you used to deny. Then is this magic, or do you not see?" (52:13-15)

Someone might ask: Ok, even if the Prophet Muhammad (SAW) lived with his people all his life, some prophets like Musa (AS) did not. How could their people know it was not magic?
Answer: Musa (AS), even though he was away from his people for a long time, brought clear miracles to them and then challenged the most learned magicians of Egypt (and Egypt was the most expert land in magic at that time).
When the magicians saw the miracle Musa (AS) performed, they all immediately understood that it was not magic, and they all accepted Islam. This is recorded in many places of the Quran. No person except one who is stubborn to the point of blame can accuse Musa (AS) of magic after those who know magic the best clearly said it is not magic.

Then Moses threw his staff, and at once it devoured what they falsified. So the magicians fell down in prostration [to Allah]. They said, "We have believed in the Lord of the worlds, The Lord of Moses and Aaron." (26:45-48)

In conclusion, Allah does not send miracles in a way that it remains ambiguous to people whether it is magic or from God. People only reject after that in stubbornness or laziness, but not because of a lack of clarity. And Allah knows best.
Answer: In general the case you said means the person is "مستضعف"
it means cant find fact or his heart cant understand the fact.
but he or she can search an ask and find the fact and may be he detects the fact by his heart .
Answer: If you do not believe in Prophet's miracle, you are not believing in Allah's ability to do that. Prophets didn't do any miracle on their own, they only did what Allah told them to and everything else is done by Allah himself.
Moses only threw the staff, Allah changed it to snake, not Moses.
Ibrahim was thrown into fire, Allah changed it in to a peaceful area, not Ibrahim.
Jesus just touched the people, Allah cured them from their disability and disease, not Jesus.
If you don't believe in any of those, you are not believing in Allah's ability to do those, nobody can believe that a fire wont burn you, but the creator of fire itself can change it. If Allah can make a thing to burn something, he can also make the same thing not to do it. So it is about Allah's ability, not just prophets miracle.
What do you mean by incapable of thinking that? Allah gave humans the ability to think for the sake of thinking about Allah's ability to do things and believe in him for that.
Human didn't create fire from nothing, he is using Allah's creation of physics to create it. If someone can believe that Allah can create fire from nothing and make it hot and burn things, then he can also believe that he can make the same thing not hot and do nothing. It is within human's thinking capability.
so believer should believe in prophet's miracle, otherwise they are not believing fully and will be asked questions about them in Judgement day.
Answer: Those that disregard the miracles as magic at very least believe in magic.
Those that know understand that upon 200 angels that landed on Mount Hermon does the responsibility lie for the craft arts taught to the human race.
There are two other angels who visit cities before their fall and are always referred to as good men. Haroot and Maroot are known to explain to those they teach magic to that the art is practiced at the price of their very own soul.
So I would believe that if one believe in magic then depending on their practices their soul is used as the currency of their actions.
So no loss if unpracticed and the cost of their soul for the use of what they believe.
Moses when encountered by magicians used what was provided to him when seeking guidance from a burning bush. His staff became a Serpent and ate the other serpents manifested by the magicians. They all told Pharaoh that what he performed was no magic that it was an act of God.
Answer: I hope you are doing well. ALLAH (Glory Be to HIM) has mentioned in the Quran

"And if they see a sign [i.e., miracle], they turn away and say, "Passing magic.
And they denied and followed their inclinations. But for every matter is a [time of] settlement."
Surah Qamar (Chapter 52 verses 2 and 3)

This happened during the Prophet Muhammad (Peace Be Upon Him) during his time when we split the moon. They knew there is no way a human being could do that. They wanted to see a sign and he delivered. However, they attributed it to magic. Not wanting to think that it could be a sign. So they were following their beliefs and not wanting to truly open up to the possibility that the miracle is real. That is the first problem.
The second problem occurred when those people kept seeing signs and they saw the nature of the Prophets (Peace Be Upon Them All) that they were teaching them morality and uprightness and kindness. However, due to the teachings it would hurt the people's egos, businesses, life styles, morality, etc.
The verse that was mentioned in full states

"ALLAH (Glory Be To HIM) does not charge a soul except [with that within] its capacity. It will have [the consequence of] what [good] it has gained, and it will bear [the consequence of] what [evil] it has earned. "Our Lord, do not impose blame upon us if we have forgotten or erred. Our Lord, and lay not upon us a burden like that which You laid upon those before us. Our Lord, and burden us not with that which we have no ability to bear. And pardon us; and forgive us; and have mercy upon us. You are our protector, so give us victory over the disbelieving people." (Chapter 2 verse 286)

So ALLAH (Glory Be To HIM) would not give signs or miracles if people could not handle it. Nor would he give His Message if people could not bear it. But people can bear it.
Now after receiving the message if we make mistakes then we ask HIM (Glory Be To HIM) for forgiveness. HE (Glory Be to HIM) only gives us basic things to do and does not overwhelm us with things that we are not capable of doing. If you are healthy and could read and write then HE (Glory Be To HIM) might take you to task more than someone who is illiterate and sick. So each person based on his capacity will be judged.
ALLAH (Glory Be To HIM) Knows Best
Comment: Salam and welcome to IslamSE the Q&A site about Islam. To learn more about our site and model consider taking the [tour] and checking our [help]. Also please mark quotation as such to clearly distinguish them from your own words and read also [answer].
Comment: Wa 3laykum As Salaam, jazakaALLAH khairan for the warm welcome. I have just fixed the quotation part.
Answer: In Surah Baqarah ayah 102 (Also known as ayat al-sihr) Allah azza waijal says
"Wretched is what (the black magicians) sold themselves for, if only they knew"
2:102
And also in the same ayat stands "They (the people who learned black magic) would not get a share in the hereafter"
So if the prophets knew magic is haram, why would they do it? I also think disagreeing with Allah azza waijal's miracles is a form of kufr(disbelieve) and Allah knows best about what happens to the people in the akhira (after life)
Comment: Salam and welcome to IslamSE the Q&A site about Islam. As is written this answer is hardly benefical you should consider elaborating and focussing ona sking the question asked. An evidence is not self-explanatory, also read [answer].
Answer: once childishly Musa A.S asked Allah to show himself to Musa A.S
Allah said no you cannot see,he insisted then on mount Judi Allah swt just showed his shadow the mountain turned to dust and Musa A.S was unconcious for 40 days.
he could have died if Allah willed.but Allah saved him and left unconsious.s you said yourself Allah does not give work beyond there capability you have been given some signs you can understand others can more or less with there capabilities.
other Prophets were given signs as they have not been given complete books as we have.
we have been given Quran which covers all types fields all of them.
be it science or engineering or pycological or emotional or etymological etc.it gives what will happen in future with you and all the universe in detail manner.
are you capable to understand.
the sign this ummah has been given is of understanding.
you plant a seed it grows in herb then tree then gives out fruits etc
it is periodical
to understand you have to sit daily looking after it
it is persistantly happening you see or not
but it is magic a seed destroys itself (can you see)
a stem comes out of it (can you see)
it grows leaves (can you see)
it grows flowers (can you see)
it grows with more leaves (can you see)
it is all magic it each phase destroys and give shape to new phase.it is uniformly happening
UNDER WHOSE EYES ? who controls excess or less food to it to grow.
so is your case Allah gives you what you can understand
you dont understand and straight away assume it is wrong. that is un-uniform.


What would be a good book for optics?

Question: I would like to refresh my knowledge about optics. I studied optics back in the university but I almost forgot everything. What would be a good book to do that?
Comment: Is there an answer provided here yet, or are you still looking for a better answer? Id someone has resolved your issue, could you select that answer as "Accepted"?
Comment: @jrista I'm actually still looking for a better answer. I know that it's better to accept a question as soon as we find a good one, this is my approach in general because this is the idea of this website in the first place. The problem with books questions is that it's subjective from person to person
Comment: Well, its actually not necessary to accept right away. On the contrary, if you need a better answer, you should wait for one to be offered...once an answer is accepted, that often tends to kill off the opportunity to get any more. I'll start a bounty on this, hopefully that will bring in more answerers.
Comment: @jrista Thanks! I agree with you that's why I didn't mark any as accepted answer
Comment: Hmm...I thought I had a bounty on this question. It seems to have disappeared though, and no one was awarded?
Comment: @jrista that's weird
Comment: Well, my 100 bounty seems to have been an utter waste...rep down the tube. SE really needs to fix bounty....
Answer: There are couple of them, but you can start with these:

Optics in Photography (SPIE Press Monograph Vol. PM06):
Explains fundamental optical principles that apply to photography, cameras, and lenses. Intended for professionals and serious amateur photographers as well as lens designers and optical engineers.
Contents

Perspective
Light Rays and Lens Aberrations
Light Waves and How They Behave
Definition and Resolution
Depth of Field
The Brightness of Images
Types of Photographic Objectives
Lens Attachments
Enlarging and Projection Systems
Stereoscopic Photography
Shutters and Flash
Camera Viewfinders and Rangefinders

The Optics of Photography and Photographic Lenses

One of my friend has these books and I have find them very useful many times.
I hope this helps.
Answer: Depending on what level of the treatment you are looking for, and if you want to go really at the foundations, you could try the classic by Born and Wolf, Principles of Optics. Great book.
A short excerpt from the Table of contents:

Foundations of geometrical optics
Geometrical theory of optical imaging
Geometrical theory of aberrations
Image forming instruments

and much, much more.
Answer: For a university level optics book, Hecht is excellent. It's what I used in university years ago (that was an earlier edition though).
Optics-4th-Edition-Eugene-Hecht
Answer: After searching this for a while, here is the list that I think it may be interesting:

Optics in Photography: Explains fundamental optical principles that apply to photography
Optics: Elementary intro to optics
Introduction to Optics: Elementary intro to optics
Introduction to Modern Optics: Less comprehensive that Optics but much cheaper
Applied Photographic Optics: Related directly to photography. The reason it's not on top of the list is because it's more complicated than others, not elementary. It was selected by the American Library Association's 'Choice' magazine as "best technical book".
Modern Optical Engineering: Technical book as the previous one.
Photographic Optics: A Text Book for the Professional and Amateur: you can find this book free on Google books.
Answer: OPTICKS can get you all the way to the source... As well as teach you some concepts (in a rather archaic but interesting way) it will expose a hint to the mind of a great(est) scientist.
Comment: I've removed combative comments and cleaned up the ones that remain. Try to just roll with the punches in the future, and if you really need to ask for a reason for a downvote, ask politely.
Comment: @ysap: Opinions happen, downvotes happen. Accept it and move along.
Comment: @ysap: There is always an ideal, but ideals need to be balanced with the reality of things. I'd love PhotoSE to be an open, objective community that always discussed the merits of everything, but the core of our subject matter often begs for the opposite. We cannot force voters to explain their votes, nor should we. I think coneslayer has been *more than open* in offering his opinion, and you should welcome that when it occurs.
Comment: @coneslayer without entering the debate on the merit of Opticks, very old books are usually much more than "historical curiosities". In the case of Galilei, Newton, Maxwell, Einstein (and others, obviously the list is very short), they are often, in my opinion, masterpieces to be studied deeply and known by heart.
Comment: Your answer was not helpful. The question wasn't about outdated 17th century works that deal exclusively with a corpuscular theory of light.
Comment: @jrista - you know that it is not about the downvote itself - and we had this discussion in the past. I would like to get the community to the point were it is *constructive*. People should explain why they are downvoting (especially when it is the 1st vote, later downvoters may just join that opinion and it is OK). This way the poster can benefit from a good criticism and possibly improve his answer, or learn something new.
Comment: Newton's corpuscular theory addresses the geometric optics, as you say, but not wave phenomena like diffraction, which I would consider important in a general recommendation to somebody who wants to learn optics. More generally, I don't think very old books are a good way to learn a topic. As a historical curiosity later? Sure. But not for learning. This is my opinion, and it's reflected in my vote. If other people think *Opticks* is a great way to learn the subject, they can vote accordingly.
Comment: @coneslayer - I appreciate your comment and opinion wholeheartedly. Note that my original complain was not about the downvote, but the lack of explanation. I guess that to the OP it is not less important to understand *why* you think it is not a good reference, right? So, let's finish this argument as friends, OK?
Comment: Btw +1 from me, for the hint to the mind of Newton :)
Comment: @jrista A perfect example, someone down voted the question without specifying any reason :)
Comment: @AkramMellice - go figure...

What would be a good book for optics?


How accurate are diagnoses on Autism to Children under 3 years old?

Question: I have a son with autism. He was diagnosed under 3 years old. 2 years old to be exactly. After I doubted several pediatricians that claimed that wouldn't be a valid diagnose after 5 years old. I discovered by myself that it wasn't entirely true. I've read that specialists would diagnose under 2, or even, babies. I want to know because other parents say their doctors say to wait from 2 to 3 years old or even more.
Answer: There was a study which examines the exact question you posed.  This study, which was conducted by Stone et al. (1999) compared accuracy of diagnosis of autism and a pervasive developmental disorder not otherwise specified (PDD-NOS).
With regard to autism, the study suggested 2 conclusions:

(1) the identification of an autism spectrum disorder can be made reliably in children below the age of 3; and (2) the specific diagnosis of autism can be made reliably in children under 3 years, as long as the diagnosticians have experience evaluating young children.  The latter conclusion is presented more tentatively, given the limited sample of clinicians employed in the present study. Further study of the impact of experience on diagnostic reliability at young ages, using lager samples of clinicians, would shed additional light on the issue.

Regardless of the initial diagnosis, the large majority of children remained on the autism spectrum at the 1 year follow-up.

Of the children who received a diagnosis of autism at age 2, 96% remained on the autism spectrum at age 3, and 72% retained the specific diagnosis of autism. Although the results suggest that symptomatology improved for 28% of these children, only 1 child (4%) improved to the extent he "left" the autism spectrum.

They also pointed out that diagnostic stability did not vary as a function of whether the same or a different clinician made the Time 2 diagnosis, proving further support for the robustness of the diagnosis.
Additional Information after issues surrounding debate were raised.
With regard to the debates over autism, there is a factsheet on the debates at autism-help.org and the debate covers the causes of autism (genetics etc), lack of definitive test for autism

due to the significant variance of symptoms among people with autistic traits, as well as a lack of knowledge about the etiology of the condition. Those with Asperger syndrome may be highly functional cognitively but lack 'social' skills, whereas others with so-called "profound Autism" may be non-verbal and deficient in elementary skills.

and there are issues surrounding the diagnosis of Asperger's syndrome as opposed to autism.

[M]any autism spectrum adults and neurotypical (non-autistic) allies in the autism rights movement do not consider Autism to be a disorder, but simply a different way of perceiving and behaving. These people believe that at least some of the difficulties encountered by people with Autism may result from prejudice and lack of accommodation from society.

Stone et al. (1999) is cited in over 200 papers including many over the past 5 years.  One of them is Roberts, et al. (2019), where they also point out that ASD can be reliably diagnosed by 24 months, although the average age of diagnosis is 2 years later.
Clark, et al. (2018) also highlights that early diagnosis of Autism Spectrum Disorder is considered best practice, increasing access to early intervention.  They investigated the school age outcomes of children who received an early, as opposed to later, diagnosis of ASD.  The abstract highlights that:

Children diagnosed early accessed more intervention, demonstrated better verbal and overall cognition at school age, were more likely to attend mainstream school and required less ongoing support than children diagnosed later.

So while raising the debates about autism diagnosis in the last 20 years is a valid argument, it does seem that the 1999 paper still stands as valid, even though changes were made in the DSM with the publication of DSM-5.  But then again, when you look at following studies,

DSM-5 resulted in 47.79% fewer toddlers being diagnosed with ASD compared to those on the DSM-IV. Toddlers diagnosed according to DSM-5 exhibited greater levels of autism symptomatology than those diagnosed with DSM-IV, but the latter group still exhibited significant levels of autism symptomatology(Matson, et al. 2012).

So has the change created a problem where some are no longer diagnosed when they should have been?  That would be open to opinion I believe.
References
Clark, M. L. E., Vinen, Z., Barbaro, J., & Dissanayake, C. (2018). School age outcomes of children diagnosed early and later with autism spectrum disorder. Journal of autism and developmental disorders, 48(1), 92-102. doi: 10.1007/s10803-017-3279-x
Matson, J. L., Kozlowski, A. M., Hattier, M. A., Horovitz, M., & Sipes, M. (2012). DSM-IV vs DSM-5 diagnostic criteria for toddlers with autism. Developmental Neurorehabilitation, 15(3), 185-190. doi: 10.3109/17518423.2012.672341
Roberts, M. Y., Stern, Y., Hampton, L. H., Grauzer, J. M., Miller, A., Levin, A., ... & Estabrook, R. (2019). Beyond pass‐fail: Examining the potential utility of two thresholds in the autism screening process. Autism Research, 12(1), 112-122. doi: 10.1002/aur.2045
Stone, W. L., Lee, E. B., Ashford, L., Brissie, J., Hepburn, S. L., Coonrod, E. E., & Weiss, B. H. (1999). Can autism be diagnosed accurately in children under 3 years?. The Journal of Child Psychology and Psychiatry and Allied Disciplines, 40(2), 219-226. doi: 10.1111/1469-7610.00435
Comment: From the outside, I've heard a lot of debate about autism diagnosis in the last 20 years and would urge caution about any source of this age. Perhaps someone can drag up a more general resource on psychiatric diagnoses in very young children.
Comment: You made a reasonable argument @CameronBrick but the thing is that that we can only operate on generally accepted criteria. With regard to the debates over autism, there is a factsheet on the debates at http://www.autism-help.org/points-autism-diagnosis-debate.htm The article I cited is referenced by 207 articles, many of which are within the last 5 years
Comment: I agree: it seems legitimate and worthwhile.
Comment: Thank you for the really thoughful and caring answer. And comments. Chris


An example of a computable problem that is not in P

Question: I am trying to find a simple example of a problem that is computable but not in P, I know very well that it would be enough to get one in NEXTIME-complete however the problems that I find in this set are very artificial
Comment: EXPTIME-complete problems are also known to be beyond P.
Comment: https://en.wikipedia.org/wiki/Time_hierarchy_theorem
Comment: See Section 6 here: https://arxiv.org/pdf/1312.5686.pdf.
Answer: As Yuval Filmus already mentioned in the comments, because of the time hierarchy theorem, we know $\mathsf{P} \neq \mathsf{EXP}$. Hence, any $\mathsf{EXP}$-complete problem is an example. These include, for instance, generalized chess and checkers.
Answer: This isn't really a natural example, but a natural technique (which I'm leaving as an answer instead of a comment since I think it's still valuable, and it's clearly too long): we can use a diagonal argument. Specifically, while we can't tell whether a Turing machine runs in polynomial time, we can whip up a list of polynomial-time Turing machines such that every polytime machine is equivalent to one on the list.
Namely, let $(M_e)_{e\in\mathbb{N}}$ be your favorite enumeration of Turing machines, let $(p_e)_{e\in\mathbb{N}}$ be your favorite enumeration of polynomials, and let $\langle\cdot,\cdot\rangle$ be your favorite pairing function on $\mathbb{N}$. Then we let $N_{\langle i,j\rangle}$ be the machine "$M_i$ cut off by $p_j$" - on input $k$, $N_{\langle i,j\rangle}$ simulates $M_i$ for $p_j(k)$-many steps, and (say) halts and ouptuts $0$ of $M_i(k)$ doesn't halt in that time. The key point is that if $M_i$ really does run in polynomial time, there is some $j$ such that $N_{\langle i,j\rangle}$ is "equivalent to" $M_i$ in the obvious sense.
Now let $X=\{n: N_n(n)=0\}$ - intuitively, $X$ is the set of $n$ which aren't in the $n$th polynomial-time-computable set. More generally, this technique lets us diagonalize out of any complexity class which is effectively describable - the reason we can't diagonalize out of REC (= the set of all computable sets) is that we have no way to "cheat" in the above manner and whip up an enumeration of those Turing machines which correspond to computable sets (= those which always halt - put another way, the set $Tot$ of always-halting Turing machines is not c.e. in a very strong way).


Is an argument in natural language as logically valid as in formal logic?

Question: Is a natural language philosophical argument which is argued strictly from first principles widely considered equally as valid as a proof written in formal logic?
Comment: @Not_Here I think not. The aspect convertible into formal logic is a triviality. The hard part is arguing for premises, and that is formally invalid if it is of any substantive interest. Balancing concerns and plausibility plays do not fit into chaining logical forms, informal validity is something else. Btw, Robinson, a designer of automated proof checkers in math, writes:"*The translation from informal to formal is by no means merely a matter of routine. In most cases it requires considerable ingenuity, and has the feel of a fresh and separate mathematical problem in itself.*"
Comment: Nobody would write a formal logic proof to make a philosophical point.
Comment: @Not_Here In informal reasoning the distinction between validity and soundness is essentially meaningless, so no. Material validity is both and neither.
Comment: Ignore the first comment posted here, they are incorrect. Usually arguments are given in natural language but it is clear that they could be fully transformed into a formal logic argument if someone sat down and worked it out. They are considered to have the same level of validity when it is clear that that translation process would be unproblematic.
Comment: @Conifold The question asks about validity, not soundness, so your comment agrees with me.
Answer: In the context of logic and reasoning, 'valid' is a property of an argument whereby the conclusion follows from the premises by necessity, or where it is impossible for the premises to be true and the conclusion false. It is possible to state valid arguments in English, or in other natural languages, provided one is careful with the terms and the syntax. An argument, such as "All elephants are mammals; all mammals are warm-blooded; therefore, all elephants are warm-blooded" is recognisable as valid, without being rendered into symbols.
But there is a serious issue with more complex arguments. Natural languages evolved for performing various tasks, but they are not ideally suited to expressing complex relationships of the kind that turn up in reasoning. Mathematicians and scientists prefer to express themselves using a symbolic language for just this reason. One could state equations using English, but it would be clumsy, long-winded, and it would risk a lack of rigour. For the same reason, logicians often prefer to use a formal language. It doesn't make arguments more valid, indeed, it is not clear what 'more valid' or 'equally as valid' could mean, but formal languages in logic can be very helpful in avoiding errors.
For example, formal languages such as predicate logic are particularly helpful in avoiding errors of scope. In English we may use a negation, or a quantifier, or a modal operator, without it being clear exactly what part of a sentence it applies to. One example of this is the quantifier shift fallacy. "Every boy loves some girl" is potentially ambiguous between there is one particular girl whom every boy loves, and there being a different girl for each boy. In English we usually understand from the context which is meant, but the ambiguity exists and is commonly exploited in a formula joke, such as "This newspaper says that a person is run over by a car every ten minutes; he should just stay in bed". Or, "According to this report, every hour a married man commits adultery. Really? Does it give his name?" Thankfully for logicians, but unfortunately for comedians, this kind of syntactic ambiguity is readily eliminated in formal languages. Another example is the modal fallacy. In English we often say something of the form, "If A then necessarily B", when the 'necessarily' part really applies to the conditional as a whole, not the consequent part of it. "If X knows that P, then necessarily P is true", expresses the fact that if something is known then it is true, because one cannot know a falsehood. But if for some X and P, X does know that P, it does not follow that "necessarily P is true", but rather that "P is true" follows necessarily. Again, this ambiguity is easily spotted and eliminated in a formal logic.
All of which is to say that formal logics are useful, including within philosophy, but they exist to make arguments clearer, not to make them more valid.
Answer: A good illustration of your question and a possible answer is the ontological argument for the existence of god.
The original argument was given by Anselm of Canterbury in the 11th century using ordinary langugage (Proslogion, Chap. 2):

Therefore, Lord, you who give knowledge of the faith, give me as much
knowledge as you know to be fitting for me, because you are as we
believe and that which we believe. And indeed we believe you are
something greater than which cannot be thought.
Or is there no such
kind of thing, for "the fool said in his heart, 'there is no God'"
(Ps. 13:1, 52:1)? But certainly that same fool, having heard what I
just said, "something greater than which cannot be thought,"
understands what he heard, and what he understands is in his thought,
even if he does not think it exists.
For it is one thing for something
to exist in a person's thought and quite another for the person to
think that thing exists. For when a painter thinks ahead to what he
will paint, he has that picture in his thought, but he does not yet
think it exists, because he has not done it yet. Once he has painted
it he has it in his thought and thinks it exists because he has done
it.
Thus even the fool is compelled to grant that something greater
than which cannot be thought exists in thought, because he understands
what he hears, and whatever is understood exists in thought.
And
certainly that greater than which cannot be understood cannot exist
only in thought, for if it exists only in thought it could also be
thought of as existing in reality as well, which is greater. If,
therefore, that than which greater cannot be thought exists in thought
alone, then that than which greater cannot be thought turns out to be
that than which something greater actually can be thought, but that is
obviously impossible. Therefore something than which greater cannot be
thought undoubtedly exists both in thought and in reality.

In the 20th century Kurt Goedel presented an ontological argument in formal logic. More specifically, he used a calulculus of modal logic:

Ax. 1. ( P ( φ ) ∧ ◻ ∀ x ( φ ( x ) ⇒ ψ ( x ) ) ) ⇒ P ( ψ )
Ax. 2. P (
¬ φ ) ⇔ ¬ P ( φ )
Th. 1. P ( φ ) ⇒ ◊ ∃ x φ ( x )
Df. 1. G ( x ) ⇔ ∀
φ ( P ( φ ) ⇒ φ ( x ) )
Ax. 3. P ( G )
Th. 2. ◊ ∃ x G ( x )
Df. 2.
φ  ess  x ⇔ φ ( x ) ∧ ∀ ψ ( ψ ( x ) ⇒ ◻ ∀ y ( φ ( y ) ⇒ ψ ( y ) ) )
Ax. 4. P ( φ ) ⇒ ◻ P ( φ )
Th. 3. G ( x ) ⇒ G  ess  x
Df. 3. E ( x )
⇔ ∀ φ ( φ  ess  x ⇒ ◻ ∃ y φ ( y ) )
Ax. 5. P ( E )
Th. 4. ◻ ∃ x G ( x
)

See https://en.wikipedia.org/wiki/G%C3%B6del%27s_ontological_proof#Symbolic_notation
, and for the whole issue https://plato.stanford.edu/entries/ontological-arguments/
Apparently, only experts in modal logic are able to follow the formal proof and to discuss its different steps. But the formalization requires that one gives a precise meaning to each term. As a consequence, one can decide whether to accept the proposed meaning or not.
References

Anselm von Canterbury: Proslogion. Hrsg. P. Franciscus Salesius Schmitt O.S.B. fromann-holzboog, Latein/Deutsch. Stuttgart-Bad Canstatt (1984)

The quote in my answer is from wikipedia. It follows Gödel's original version from his heritage. The following paper quotes and comments the steps from the heritage:

Jordan Howard Sobel: ON GÖDEL'S ONTOLOGICAL PROOF, see
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=8&ved=2ahUKEwiWlNyJlcjgAhXNyqQKHTl0CIoQFjAHegQIARAC&url=http%3A%2F%2Fattach3.bdwm.net%2Fattach%2F0Announce%2Fgroups%2FGROUP_0%2FPersonalCorpus%2FA%2Faelfinspring%2FD8FA5B6F8%2FDC638E613%2FM.1193067187.A%2FOnGodel(toKoons).pdf&usg=AOvVaw3qwj23_1r44uHRH6WaEPy2

For an explication of the steps from Gödel's proof see also @jqxxxx https://math.stackexchange.com/questions/248548/g%C3%B6dels-ontological-proof
Comment: This is an interesting example, but one should note that Canterbury's argument is of quite different nature than Gödel's. The argument can be understood by anyone putting some time into it, especially since there are nice expositions of it, like "Types, Tableaux's and Gödel's God", by Fitting. If you look into that book, you will clearly see in what sense natural language has precedence. The logic has to be constructed, only so that the argument can be formalised.
Comment: This paper: https://www.ijcai.org/Proceedings/16/Papers/137.pdf demonstrates a modal collapse in Gödel's premises, within S5, or any modal system that includes T.
Comment: There are several different versions of the ontological argument, e.g. those of Anselm, Descartes, Gödel and Plantinga. They all work from somewhat different premises, so I wouldn't say that Gödel's version is a formalisation of Anselm as such. Also, it is worth noting that Gödel's argument has been shown to have inconsistent premises, so it is valid for all the wrong reasons!
Comment: @Jishin Noben Do you mean that Goedel's formalization does not meet Anselm's argument?
Comment: Nowhere to the best of my knowledge has such a thing been shown @Bumble. Jo Wehler, Gödel's argument is not a formalisation of Canterbury's. Both are classified as ontological, but the details are vastly different. For example you won't find any reference to mind or thought in Gödel's argument and in Canterbury's goodness is not mentioned.
Comment: @Bumble I know that Gödel's formalization has been critized and that alternative formalizations of Anselm's argument have been proposed. You find references even in the paper I quote. But IMO it's not the point of the OP how to evaluate different formalizations.
Answer: Humans don't think in symbolic logic, so if a human can understand an argument presented in symbolic logic, then they could express it with some other notation.
The main problem with expressing logical arguments in natural human languages is polysemy. For example, the word or can mean both inclusive and exclusive OR. The word if sometimes means "if and only if", and sometimes it doesn't. But it is possible to develop subsets of natural language where these words are defined unambiguously. Or new words are coined, such as iff.
Although logical arguments was not the reason why the Natural Semantic Metalanguage (NSM) was developed, it is interesting how many logical constructs have been identified as semantic primes: THERE IS, ALL, NOT, BECAUSE, IF, TRUE. For these to have been accepted as primes means that there is good empirical research that these are universal concepts shared by all languages. This means that not only can most (perhaps all) logical arguments be expressed in natural language, they can be expressed in all natural human languages.
Answer: It can be. Take the definition of deduction by Aristotle

A kind of discourse, that something having being stated, some other statement follows that is different from the preceding by neccessity.

Aristotle says 'discourse' and there are many kinds of discourse and not just the purely formal, that many think of when they hear the terms logic or deduction. It's interesting, to me at least, that Aristotle writes that a deduced statement should be different from the preceding.
This careful, and at first sight - pedantic - language marks him, at least in my eyes, as being of a more scientific bent than his predecessor, Plato. I would say, even as a modern. Except of course that is wrong. We write like this because he wrote like that and his influence went deep. It merely highlights the scientific inheritance from Aristotle. It's also interesting, because in the plentiful superficial literature about him, I mean in the anti-Aristotelian literature he is belittled as being anti-science when in fact he was laying the foundations stones of science.
Answer: It depends on how you define "valid".  If you are using the formal, technical definition of valid as certifying an argument in a system of formal logic, then no, a natural language argument cannot be valid in that sense.  It must first be translated into a a formal argument, and then evaluated for validity.
There are cases where a natural language argument seems identical to a formal language argument --it may even be expressed in the same words --but there are inherent ambiguities in natural language that are explicitly removed in formal languages.
It is quite possible for a natural language argument to be so readily translatable into a formal argument that they are essentially treated as interchangeable, but calling a argument of this type "valid" is a distinguishably different use of the term "valid" --it is, to be exact, a natural language usage of "valid," not a formal language one.
Comment: +1 I agree that the description *valid* should only apply to arguments in a formal logic. There is too much ambiguity in natural language for the relationship between premises and conclusion to be necessarily so that validity requires.


What is the meaning of "interview loop"?

Question: While preparing for job interviews, I keep coming across the term "interview loop". The phrase "interview loop" seems to be used interchangeably with "interview".

What is the meaning of "loop" here, then?
And what is the etymology of this usage?

--
Comment: As far as I can tell, the "interview loop" term was used by Microsoft and popularlized by Amazon, to describe a typical tech company interview with multiple people in sequence. But I found occasional usages back to 1968. An Amazon reference: https://www.businessinsider.com/amazon-insiders-explain-the-companys-loop-interview-process-2020-1
Answer: "Interview loop" refers to a process where you take a candidate, have them interviewed by various people and possibly also carry out testing, portfolio evaluation, etc, often over the course of a day or morning/afternoon, but maybe longer (multiple days). It's different from an interview in that it may involve multiple interviews/conversations with different people in the company (e.g. speaking to people from different departments), as well as possibly involving testing or other evaluation.
It can refer either to the interview process or specifically to the panel of people conducting the interviews. In the former sense, "loop" presumably means a part of a cycle, running through the full process for a candidate, a smaller part of an interview process which may involve multiple loops. In the latter sense, "loop" probably means something similar to "ring" or "circle" as referring to a group of people with nobody in overall authority; also compare the expression "in the loop", meaning part of the group who has knowledge and/or power to decide. It's a short leap semantically from a group of people to the process they are conducting, or vice versa.
There is a Stack Exchange for workplace topics, https://workplace.stackexchange.com/ if you want ask about what interview loops involve (rather than questions about meaning or etymology).
References

https://lethain.com/designing-interview-loops/
https://www.zippia.com/employer/how-the-big-companies-hire/
https://blog.aboutamazon.com/working-at-amazon/how-amazon-hires
https://www.uxmatters.com/mt/archives/2017/01/advice-to-candidates-on-successful-ux-interview-loops.php

Note that more rarely, the phrase can also refer to a cycle where a candidate is forced to interview over and over again and never gets a clear answer. This often happens in dysfunctional companies, where either nobody has the authority to take on new staff, or they can't come to a decision on a hire, or some other reason. https://www.jeffersongroup.co.uk/blog/escape-interview-loop/
Answer: The Interview Loop
An interview is an opportunity for the candidate to expose to you their abilities. You only have an hour, the amount of information gained per minute is worth trying to optimize. Try keeping this model in your head during the interview: Think "What more do I need to know to make a decision?
Comment: Okay, but what does the "loop" part mean?
Comment: @nnnnnn It's management-speak. It doesn't have to mean anything. :P


Can one lose jhana?

Question: Once one has learned how to obtain and maintain jhana can the ability be lost (i.e., forgotten), due to lack of use.
Comment: It sounds like you're asking two different questions.  The first is whether one can lose the insights gained from jhana.  The second is whether one can lose the ability to enter and maintain jhana.  Could you clarify?  Also, if you meant the former, could you clarify what you mean by losing insight?
Comment: Thanks, didn't mean to confuse.  The question is not about insight,  I don't believe you can lose insight.  My question is once you have learned how to attain jhana,  if you don't practice it for a while can you forget how to achieve it?
Comment: I've heard the word 'jhana' used (those of form and formless) which seem to be states of mind though I am probably mistaken. The context I heard them in is that one gives up their pain and pleasure to reach the final jhana which has just equanimity. It may benefit other readers to add some background information in the question.
Comment: Jhana translate to Chinese as "Chan", and to Japanese as "Zen". I am from a Vietnamese & Japanese style so we call it Zen mostly.
Answer: This is a possibility with regard to mundane Dhyāna / Jhana. One such instance is Devadatta

One good example from the Buddha's time was Devadatta, who was a brother of princess Yasodhara. Devadatta became a monk and developed the mundane jhanas and attained those direct knowledges described above. He could perform many "miracles", and one time he appeared in the bedroom of Prince Ajasattu to impress him. But when Devadatta went against the Buddha and at one time injured the Buddha, he lost all his mundane powers and ended up in the lowest realm (avici niraya) because of those offenses.

Also

There is this story about a yogi who was travelling by air with abhinna powers and saw a flower in the shape of a woman (called "närilathä") and lost the jhanic state and came down; there is another such story where the yogi heard the singing of a woman and had to face the same fate.

Source: Power of the Human Mind – Anariya or Mundane Jhanas
Comment: It is amazing how different our traditions are between yours and mine. But it is even more amazing how the dharma seems to transcend both of our traditions. Even though you often recite texts and sutras that I as a Zen practitioner have never read or heard of, it brings me great joy to find and explore the dharma in what you have to say.
Answer: Yes you can. Forgetfulness is very common. Everyday I lose/forget jhana throughout the day and everyday I have to wake up and remember again. It is a daily, moment to moment practice to remember the jhana.
Here is a story from Zen Flesh, Zen Bones.

Zen students are with their masters at least two years before they presume to teach others. Nan-in was visited by Tenno, who, having passed his apprenticeship, had become a teacher. The day happened to be rainy, so Tenno wore wooden clogs and carried an umbrella. After greeting him Nan-in remarked: "I suppose you left your wooden clogs in the vestibule. I want to know if your umbrella is on the right or left side of the clogs."
Tenno, confused, had no instant answer. He realized that he was unable to carry his Zen every minute. He became Nan-in's pupil, and he studied six more years to accomplish his every-minute Zen.
Answer: First of all, You can switch the Jhana to turn on and off.
Sexual intercourse and Alcohol might reduce the concentration for a while tho.
Once you become a stream-enterer, it's not possible to lose your Ability to get into Jhana.
Breaking the Precepts will help you lose your ability tho because a lot of hindrances will popup and hinder your concentration.
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](http://chat.stackexchange.com/rooms/58388/discussion-on-answer-by-lomx-can-one-lose-jhana).

Can one lose jhana?


How to include buttons in Civimail

Question: I want to include two buttons in civimail template Accept and Decline. If the user clicks on accept/ decline button, It should notify the administrator with an email.However I can add buttons using HTML.But how do I make this to notify the administrator with an email?Please suggest.
Answer: How about link your two buttons to two different URLs (confirmation pages) "Thank you for voting yes"; "Thank you for voting no" and use the CiviMail track open/click through feature to see which Contacts clicked which buttons.
Answer: Create "Accept" and "Decline" landing pages and link your template to them. Use the Mailing Report to track who has accepted or declined.

How to include buttons in Civimail


At the beginning of the movie, why did little William and Duke Hammond assume that Snow White was dead?

Question: They really wrote her off rather thoughtlessly, no? Why not work hard to figure out for sure that she's dead?
Answer: Firstly, they left her behind in the middle of a battle. There's a chance that in the midst of the chaos, Snow White will get hurt - whether it's deliberate or accidental. Being a child, it wouldn't take much to deal her a fatal blow. Think about it - someone shoves her out of the way, her head hits a rock and she's probably dead. I'd say the immediate odds are not in her favor.
Assuming she makes it out of the battle, Snow White will inevitably come before Ravenna. She's really too young to escape on her own; her odds of survival alone would not be good. Knowing that Ravenna has just killed the king, it seems very reasonable to assume that she might just kill Snow White then and there. Why she does not is an entirely different question, but again, the odds are not in Snow White's favor.
Barring the immediate threats that would make William and Hammond assume Snow White dead, we have to consider the period of years during her imprisonment. The movie makes it clear that Hammond's castle is a journey of several days away, through some rather nasty territory. We also learn that they are raiding Ravenna, but cannot confront her outright - suggesting that they have rarely been inside Ravenna's castle. Even the two men that get captured and taken inside would never have seen or heard about Snow White - except that she escapes right as the elder man is leaving. Moreover, that man's son was killed as punishment; again, it's not unreasonable to assume that any other men of Hammond's that made it into the castle never came out again alive. Getting news of Snow White out of the castle seems unlikely.
On a further note, Snow White was imprisoned up in a tower. The only people she saw were the occasional other captive put in a cell nearby (like Greta) and her guards. I have a strong suspicion that her guards do not know who she is, a suspicion reinforced by the fact that when Ravenna decides to kill Snow White, she sends her brother personally instead of a guard (remember - the men Ravenna brought in to take over the castle were hers, and would not have known Snow White). If this is true, it would make it even harder for news of Snow White's continued existence to escape the castle. William and Hammond's surprise is not entirely unbelievable.


How is a Raspberry Pi different from an old phone

Question: I've been looking into getting a Raspberry Pi, but I end up needing a case, a display, and some way to power it, and wanting some degree of portability. It seems to me that even the most outdated cellphone has far superior features (screen, touch screen, Wifi, 3g/4g camera(s), battery etc) in a much better form factor. The only thing that is missing are the digital/analog in/out pins. So why not flip it around and make a USB or bluetooth peripheral board with just the pins?
Answer: If you have a phone that can run a full Open Source OS, with full access to the hardware, then perhaps you indeed have a better solution than what a Raspberry Pi can offer. Note that people have taken the processor from modern phones and turned it into a Raspberry-like board already (See the Odroid board at www.hardkernel.com). However, most phones do not cost $35 (not without a wireless contract at least) and do not have GPIO, I2C, UART and other pins openly accessible. The Raspberry Pi is geared towards people who look for an easy to use, open, programmable environment for learning all about computers and electronics, and also attracts hobbyists and professionals who like the standarized format and broad support this board gives. But it is only one of many possible solutions. Odroid, Arduino, microcontrollers - all have their own use cases and audiences.
Answer: I think this depends on what it is you are interested in doing.  As Phil B. points out, the pi has a lot of things that a phone does not,1 and as you point out, a phone has a lot of things a pi does not.  They are two different things ("apples and oranges").  While there are cars that are also boats, most people who have cars and want boats want the boat separately.  Of course, if someone came up with the perfect car-boat, that might change, but do not hold your breath -- it may be a very misguided concept.

So why not flip it around and make a USB or bluetooth peripheral board with just the pins?

You would not have the same potential with that -- the pi GPIO pins are processor pins.  They are the kind of thing that is used to implement a bus (such as USB) from the processor to a peripheral.  You could simulate the concept with a peripheral on the other side of a bus, but it is hard to see who would want to use such a thing and for what.
Keep in mind the pi is not a piece of consumer electronics.  Although it is used as a media player, I think if that kind of thing is your primary interest, then other than being really really cheap it does not have much going for it.  Put another way, if you are looking at it in terms of the kind of things you would do with a smartphone, it is not for you -- you will only end up disappointed and frustrated.

1. A pi has things even a $3000 desktop does not have.  You cannot really access the I2C bus, etc., on a normal computer.  This is why it is called a development board.
Answer: I use both old Android phones and Raspberry Pis. Each has strengths that the other cannot easily reproduce.
An Android phone is fine if you're comfortable with developing Android apps and being limited to the features you have access to. On a rooted phone, you should have access to most features. The phones have an impressive array of sensors (light, compass, GPS, more), a built-in battery/UPS, outstanding cameras and wifi. If you want these features in a handy, self-contained package, a smartphone is hard to beat. I can buy a Droid Bionic for roughly $65 used, and use them as remote network cameras, polled by my Linux server running motion.
The RPi lets me run mainstream Linux programs such as Node and Flask for server development. They provide a cheap platform that I can use for open source development using a bewildering array of languages and pre-built, free libraries at no cost. Programs written for the RPi can typically be run on a full desktop and vice-versa (within the limitations of hardware). I can also use the array of powerful open source software tools that previously required me to haul around a couple of laptops in a convenient form factor. I have used the camera module, but it pales compared to the smartphones for quality (though it's certainly useful for other purposes). It has no battery, but I can plug it into a 10,000 mAh battery for hours of use when needed. I don't do hardware development, but even without the GPIO capabilities, the RPi is irreplaceable for me. The RPi can be plugged into a wired network, or configured as an access point or wireless monitor. I can plug the RPi into a monitor and use a USB keyboard and mouse for comfort. I can plug 8 USB-serial adapters into a hub and use it as a serial terminal for configuring network equipment. I use RPis for network testing. My typical RPi costs about $85 (RPi, case, power adapter, 2 USB wifi adapters).
So while you could, conceivably, make one to much of what the other does, there's no real reason to do so. They won't do it as well, and you'll have to make compromises. They are different beasts. They compliment each other in many ways (phone makes good user interface to wifi-connected RPi). It's not a zero-sum game. You can use both.


How much do real-estate prices correlate with apartment rental prices?

Question: I've been trying to find sources that mention this, and have tried to find graphs of data so I can compare myself, but I haven't been able to. Do real-estate sale prices correlate positively, negatively, or not at all with apartment rental prices? A more nuanced answer than that is also appreciated.
Answer: In theory there should be a direct positive correlation (especially in countries where house prices are a part of the index which is used to define rental rates), but in reality there is a lot of variation in the results for this question depending on the country, possible effects of different laws, the business cycle, whether new housing is being built or not, etc.
For Italy, Manganelli, Morano and Tajan (2014) in "House prices and rents. The Italian experience" study response functions and conclude:
2)  Rents depend on real-estate prices, the short-term interest rate and the differences between actual and expected GDP with a one year delayed reaction.
On the other hand, Ambrose, Eichholtz and Lindenthal (2013) in House Prices and Fundamentals: 355 years of evidence, Journal of Money, Credit and Banking find that when housing prices stray from equilibrium growth, rental rates do not react the same way even if it takes decades for the prices to return to steady growth.
For a recent study on U.S. data (model built to match trends from 1960-2013), I'd check Gelain and Lansing (2014): House prices, expectations, and time-varying fundamentals, Journal of Empirical Finance
Comment: Very informative! Pretty interesting that one study concluded there was a 1 year delayed reaction. I would expect that rental rates are saner than housing prices, which I think is what you're saying the Ambrose et al paper concludes, since there's no real ability to speculate in rental prices.
Answer: A apartment is usually a set price for all the same units as for real estate pricing they usually base what the monthly payment will be from how much was put down on the house and how many years you choose to pay it off. Not saying that there can't be similar in pricing which depends on where you are living such as city and state.Indaina Reia provide a new real estate guidlines.
Comment: I proof read your answer for you:
Each unit of an apartment usually costs a set price. As for real estate pricing, the monthly payment is usually based on the amount of money put down on the mortgage and the length of the mortgage. I'm not saying that they can't be similar in monthly price, though, since it depends on what city, state, etc you're living in. Indiana REIA provides new real estate guidelines, that ...? .


Local volatility and Stochastic Volatility

Question: Please help me understand similarity and differences between local volatility and Stochastic Volatility both intuitively and mathematically.
Comment: I wrote a bit about this topic in another answer, here: https://quant.stackexchange.com/questions/44300/mixed-local-stochastic-volatility-model-in-quantlib/57147#57147
Answer: I'll try my best to explain them
Both of them aim to match the implied volatility surface as shown by the empirical data.
Local volatility process is a function of Stock and time without any stochastic term (not moving randomly). It changes with with different inputs of stock and time. It matches the implied volatility surface with short term maturity very well, but not well with option with long maturity.
Stochastic volatility is simply volatility that varies stochastically (it moves randomly). It can have mean reverting properties. It matches long term implied volatility surface well, but unable to replicate short term implied volatility skew or smile
Comment: I'll answer them according to the numbers you have set. 1. No, they are both different thing. In fact, there are such things called local stochastic volatility model. 2. I am almost surely that the answer is no. Only stochastic volatility has it. 3. Local stochastic volatility model and it's popular :)
Comment: Thank you for your response. I have few follow up queries. Would we great if these get clarified. 1.Is  local volatility a subset of Stochastic Volatility. 2. Do both local and stochastic vol have mean reverting properties or just Stochastic vol? 3. Is there any mathematical relation connecting the two types of volatility?
Comment: Thank you so much for clarifying things. Please let me know if i infer it correctly: 1. Here we are taking about volatility of the underlier and not the volatility of the option premium. 2. Volatility is a function of spot, time, interest rate , and various other factors. If all the factors that affect volatility are considered it is called Stochastic volatility and if only spot and time is considered it is called local volatility?
Comment: I dont understand ur first question. For the second question: Local volatility can be actually function of spot tkme interest and other factors just without "stochastic" term. Stochastic volatility normally do not take in any other financial factors except volatility itself
Comment: Thank you for your help. I have got a high level idea but am still not very clear and able to distinguish between the two. Any reading or video explanation would be really helpful. If you have any please feel free to share them. Thanks.


A Big List Type Question

Question: A commenter on an answer of mine recently asked me to provide some information an offbeat, but good axiomatization of Euclidian geometry. Having little access to on-line Tex typesetting, I am considering asking a question of the sort "What are the various axiomatizations of geometry?" and then promptly responding with Hilbert's, Birkhoff's, Prof. Lee's postulate lists as answers on community wiki. Is this appropriate?
Admittedly, you can find most of this stuff on-line (Birkhoff's postulates, SMSG postulates etc.), but you need to know what you are looking for and be specific. It might be nice to have that all in one place.
Or perhaps there is a better way.
Comment: Seems viable (and like a good idea) to me.  I'd suggest flagging the question for moderator attention to be made CW immediately after asking; for the answers you want to post immediately, you can make those CW yourself.
Answer: I think this would be fine. Certainly it's not a crime to have an answer to your own big-list questions. (It's not even a crime to have an answer to your own ordinary questions, although I am somewhat less fond of this.)

A Big List Type Question


How do I embed an image into CiviMail messages?

Question: Is possible to embedd images into civimail mailings? Would be great to have a choice between loading images from the server and sending them along with the mailing. For example Acymailing have this option. Is it possible in CiviMail?
Comment: Docs: https://docs.civicrm.org/user/en/latest/email/everyday-tasks/#inserting-an-image-in-an-email
Answer: If you are referring to embedding images in the body of the email, yes, that is entirely possible in CiviMail.
Using the WYSIWYG editor, you can embed images. There is an image icon on the toolbar to do this.  The images will be stored on your server and can be referenced in the HTML email.  (Of course you could optionally just include the image hosted at a different URL as well.)
You could theoretically embed the byte stream of an image, though I don't know why you would want/need this.
If you are referring to attaching the images as attachments that is possible too.  Check the Attachments section when you are defining the email in CiviMail.
Answer: You can embed an image (rather than a link to the image) directly into an email by viewing the image in any image editor and then copying and pasting the image into the CiviCRM HTML email editor.
Doing so has several undesirable effects however:

The image will be stored in your database rather than as a file. If you send a lot of large pictures over a period of time, then your database may grow unreasonably large making maintenance tasks such as a daily backup more difficult.
Users on slow or pay-by-byte connections may be displeased.
Answer: I have the same requirement for my organization. I want to be able to embed the image into the email body. I think you need to convert the image to Base64 encoding - see this stack exchange post on the topic.


When should you inform your employee that they are getting a raise

Question: I've got a 10% raise for an employee approved, but it starts from when he is going to make 1 year with us (which is in a couple of months). But the usual compensation talks period for the whole company is this month. Should I have a meeting with him now and inform him that he will get a raise? Or should I postpone this meeting closer to the date he'll actually get it?
Comment: What do you believe the downsides of telling him early are?
Answer: It depends on the company policy. Usually you will get confirmation from HR or your management on when its OK to share. Once you have the confirmation, you can discuss. Since you have mentioned the usual period is this whole month, just double check with HR/ Management once and communicate this.
If no one replies to you, in that case, its better to communicate that raises have been approved but avoid the numbers or quantum of approval till you get a confirmation. It may also be helpful to talk to some seasoned managers in the organization to confirm what has been the norm in the past for the communication.
It is common for the raises to be shared a month or two before they are applicable. However, a go ahead is only given once the budget has been approved by the senior management, typically at CEO level.
One more thing to check is when other members of your department are getting the communication. If everyone else knows their numbers ( that should also include you if you are eligible) and you skip your direct reports, it will also lead to unnecessary tension. People will assume they are not getting hikes. So its important to share the communication around the same time when everyone else is getting it.
Kindly ensure that you communicate the effective date of the raise to avoid any confusion, particularly with the new joiners who may not be aware on how the raises work in your organization.
Answer: I disagree with other answers on telling him early or telling him now.
Unless you can give him a official revised salary letter indicating the new salary and raise, you should just tell him that his compensation will be discussed when he completes an year. Do not indicate raise leave alone the amount of raise.
While 2 months is short time, it could be long enough for financial decisions to be reversed due to some unforeseen circumstances.
Comment: In that case the employee would be absolutely pissed off; I would leave ASAP if that happened. Basically everyone would have got a raise except him, because he joined at the wrong time.
Comment: +1 for informing him it will actually be discussed at the end of his first year. He is part of the company, he can't be left out from a process advertised to be for every employee.
Comment: I had this happen to me at a previous employer.  I was told I was getting a raise in June.  Based on this I bought a new car as the raise was about a car payment.  Then was told the raise was not happening for "financial reasons".  This was at one of the largest banks in the country,  I was laid off from this employer 7 months later.  I was given an even larger raise on my last day which wen into effect for my 12½ severance period.  These guys really did not know what they were doing.
Comment: @gnasher729 That may be the case but I think he will be less pissed off than what he can be if something promised is reversed. Also, it is not like "everyone except him",  it is 'everyone except those who are in their first year".  Lot of companies I worked for handled first year raises differently.  Everything is on the companywide cycle after completing one year.  (Although not sure if that is the case with OP's company)
Answer: Nothing erodes trust in management as quickly as a broken promise. But leaving him entirely in the dark is likely to make him feel overlooked or ignored.
I would suggest you schedule a short meeting in which you ensure that he has all the details that you can give him (reiterate company policy, etc), without risking a broken promise. HR should be able to advise you on this*. If you can't give him a certain answer today, schedule a second meeting around his anniversary. During the initial meeting you only tell him he's being considered for a raise (and under what conditions he may or may not get it). It is the best you can do for him, and he'll probably see it as an honest and respectable gesture.
*HR and payroll will have more details about the process. If the raise is already approved and processed, so that he is guaranteed to get it automatically after his 1-year anniversary, then you may be able to tell him safely. If it is subject to his performance in the coming months, or if a policy change could lead to the raise being scrapped, then you must be careful.
Comment: I agree with this answer.  If the raise that has been approved is due to the employee's performance in the last year, explain that their raise will go into effect, after their service date (the date they joined).  If you can tell them, how many pay periods after that date they will see the raise, I am sure they will appreciate that information.
Answer: If HR has given you orders, do what they say.
Otherwise, everyone will know that raises will be discussed. The new employee may assume that they are the only one left out if you don't talk to them, with negative consequences for motivation, jealousy and so on. Easy to avoid by giving them the news at the same time as everyone else.
Comment: 'The new employee may assume that they are the only one left out if you don't talk to them' - Not necessarily. Reasonable people will know they are only there for less than a year, so they won't expect raises so early - or maybe even not at all.
Comment: Nonsense. This company is actually unusual. Either everyone gets a raise every anniversary of their start date, so raises go through the year, or everyone gets his on the same day, with newcomers getting a pro-rated raise.
Comment: So what if you are 5 months employed to the time of the year, still within probation time? What if it's 6? 7? 8? Or just 2, 3, 4? Where do you draw the line? What if there is effectively a second probation time of 12 months, in which the employer can still decide to continue to contract or not? The most reasonable thing is to not expect any raises during the probation time(s), but to expect a larger scale talk at the end of these 12 months, in which some form of evaluation and negotiation can occur. Then you let the employee shift into the yearly period, regardless if it's 1 or 11 months.
Comment: Where, of course, if the time difference is too short, and nothing relevant occurred, you keep things as they were recently discussed. The idea of "feeling like being the only one left out" is *actually* nonsense - unless that employee is *actually* neglected in these regards for more than a year, or even two.
Comment: @Battle "Where do you draw the line?" That's daft. You give one twelvth of the annual raise for every month the person is there. Very simple. And if you don't do it that way, you have a problem the next year - unless everyone gets their salary adjusted on every anniversary of the joining the company.
Comment: So you'd give the employee a raise of <1%, 1 month after being employed, while still in probation time, not knowing anything if that oh-so significant raise is even justified, only because he might "feel left out"? Raising a wage is a matter of decision and negotiation, also based on performance. You don't just hand out raises blindly like a robot - a very simple robot.