If all the citizens have same rights why some must pay a higher tax rate?

Question: If all the citizens of a country have the same rights and are equal before the law, why some must pay more taxes? Isn't that a kind of discrimination?
Comment: People do not have equal rights. Adults have the right to vote, children do not. Someone with a PhD has the right to use a certain title, others do not. It's only a small subset of rights that are guaranteed for everybody, usually those are listed in the constitution. Many other rights can be earned or revoked.
Comment: A politically popular discrimination :)
Comment: Not all discrimination is illegal, amoral, or even undesirable. The Government has no mandate to eliminate all forms of discrimination.
Comment: Because governments don't tax constitutional rights, they tax income. And you are forgetting consumption taxes, a form of flat tax that hurts the low-income people because they spend a larger slice of their income compared to the richest.
Comment: Do you mean more in dollars or a higher percentage?
Comment: What right is being violated when a person who makes more money is taxed more than somebody who makes less? It's wealth based discrimination, and "wealth" is not a protected class.
Comment: There is no relationship, explicit or implied, between taxes and rights, nor is there a right to not be discriminated against except for explicitly-defined categories, like race, religion, gender, or age.
Comment: You can escape that "discrimination" by stopping to work or getting a job that pays less.
Comment: Why? Because of math, mostly.
Comment: @DVK, A higher percentage usually means more dollars, but more dollars does not necessarily mean a higher percentage. A flat tax of 5% for all people is 5% for all people, but if I make more than you, I pay more in dollars. Mostly I was wanting to see if the OP considers the flat tax as "fair" or "non-discriminatory".
Comment: A better question is if only individuals have rights, which are then loaned to governmental bodies for common defense and protection of rights, then citizens cannot delegate rights to government that they do not have themselves. There is no individual right to forcibly take money without consent, it is in fact a victim-based crime, which is a punishable offense, so is all taxation based on rule of the mob ?
Comment: Is it discrimination that only the very wealthy have the means to evade the vast majority of the taxes they owe?
Comment: Governments exist to make decisions. Every decision is technically a form of discrimination. Having a national park is discrimination against the opportunity to cut down all the trees in the park. That does not mean national parks are a bad thing. (See my answer.)
Comment: Isn't the same tax rate for everybody discrimination as well, because it results in richer people paying more taxes? Isn't the only discrimination-free way that everyone pays the same amount of taxes, lets say 1000$ per month, regardless of income? You see, "discrimination" is a very flexible word here...
Comment: @mikeazo - usually amounts to the same thing, with rare exceptions (the latter, when someone is very rich, and has only capital gains as income and not wages).
Comment: @SGR: black work is not a particularly high-class occupation over here...
Comment: Equity vs  Equality
There's your answer in 3 words.
Comment: You may saw it as unfair. But actually, it is also good very good for the elite. If the poor can consume, the economy works well. When the people can't afford anymore to consume you have an economic crisis.  Moreover, don't forget the cycle of strife. When the rich people are too rich and too numerous, you have redristibution or bloodshed.  What is the point of being rich if you end up killed in riots or revolution ?
Comment: Why do some get less income? If someone is unhappy with the taxes they pay, they should speak to their employer and ask for a pay cut.
Comment: Thankfully, there is an easy solution for such awful unjustice that doscriminates against the rich. They can just earn less money, and *presto!* they will pay less taxes. I just really don't understand why they prefer to earn more money albeit this forces them to pay more taxes... must be some kind of compulsive behaviour.
Answer: As opposite to the assumption from the question, if all citizens have the same rights, why can't some of them use something, what other can?
Why can't an unemployed use a limousine, a yacht or a house with swimming pool? Isn't this the discrimination?
The equal rights mean that two citizens in identical situation will be treated the same. So, two citizens will pay the same taxes if they have the same material status etc.
From philosophical point of view the reason why some people must pay more taxes than the others can be answered with my inversion of your thesis: they must pay more taxes because they can use more goods.
Comment: That's the point, Dunk. Poor people can't own a yacht or use a limousine The question is why is that acceptable, and not considered a form of discrimination?
Comment: Your examples fall flat as does your claim of answering the question. Anyone can use a "limuzine", yacht or house with a swimming pool as long as they pay for it. Everybody has the exact same rights in that regard.  Also, I don't see how "they can use more goods" implies that they "must" pay more taxes. The only way that could possibly be a reasonable or rational conclusion is if those goods were being provided by the government.
Comment: @DJClayworth you have confused freedom for power, everyone is free to own a yacht or a limousine not everyone has the power to own one. No one is discriminated against by this.
Comment: @Dunk Anyone can get rid of their richness and  enjoy the treatment of the poor
Comment: @user1450877: Two people go to the Ferrari show room and each says I want to buy a Ferrari. One gets it, the other one doesn't. How is that not discrimination? And please look up the meaning of "discrimination" in a dictionary. Nobody is claiming it is a form of illegal discrimination, but legal discrimination.
Comment: @user1450877: But why only people who can pay the price?
Comment: Owning a yacht, house, limousine, or swimming pool isn't a right. It's a privilege, that is purchased through accumulated wealth. Wealthy pay more taxes, arguably, because they have benefited more from the system the taxes support.
Comment: @gnasher729 anyone that can pay the price can buy the car, anyone has the freedom to buy a Ferrari, that is their right. Both may not have the power to buy the Ferrari. There is a clear difference between someone having power and freedom, the main one being for government to give someone power they must first use violence and coercion to take it from someone else.
Answer: Literally speaking, yes, it is a kind of discrimination, although not in the usual sense of the word.  It discriminates between citizens based on their income or property, but not usually based on personal characteristics such as sex or age¹.
As to the "why" question, I'd like to add one point to @maple_shaft's extensive answer. A progressive tax rate may be used as an instrument to level out differences in wealth. The highest income brackets have a higher tax rate. This reduces the difference between poor and rich, which has many advantages, for example:

It benefits economic growth more if someone living on the minimum wage gets X $/month extra than if someone already rich gets X $/month extra, because the poor person is likely to spend every single extra $ they get, whereas the rich person may just put it on a savings account or invest it in Chinese factories.
A reduction in income differences may increase social stability and reduce crime.

Of course, there are also disadvantages. Perceived fairness may be one of them, as is the consequence that working more would not add as much extra money in ones pocket as it would otherwise. But I think most (but not all) legislations have some form of a progressive tax rate.

¹Some policies may have the apparent effect of discriminating based on age; for example, in some legislations, income from labour may be taxed at a lower rate than income from pensions, but it's not age per se that is the factor of discrimination.
Comment: Citizens aren't equal. No system claims they are and democracy doesn't require that.
Comment: @DVK there were two questions: "why must some pay more tax?" and "Isn't that a kind of discrimination?". My answer answers the first question.
Comment: So then citizens aren't equal, they are different because they wealth? so the basements of democracy are just lies?
Comment: -1. The question asked whether this was "equal rights", not whether it was useful to achieve some (good or bad) social goal while being unfair/providing unequal rights.
Comment: (-1) This is completely confused thinking. People paying more taxes because of some personal characteristics is a discrimination. But progressive tax rates, incentives of all kinds, taxes on specific products apply equally to anybody and everybody.
Comment: @AlbertoBonsanto Nobody is truly equal.  Life is a painful lesson in inequality.  Some people may be born with a terrible disorder that makes life short and painful for them.  This runs at odds to those of us who value Justice in this world above all else.  What democracy guarantees is that everybody gets to vote on the guys who make the rules, and my vote is equivalent to a billionaires.
Comment: @Relaxed Discrimination means "to make a difference".  I interpret the word literally.
Comment: @Evargalo Apart from the ultra-rich in countries where there is so much tax evasion that public services are very poor; those ultra-rich hire private security guards, fly around in private jets, go abroad for private healthcare, send their children to private schools.  But for the European or North American (upper) middle class what you say is probably accurate.  Interesting point!
Comment: @gerrit those who fly in private jets arguably benefit more from the existence of airports and other infrastructure such as air traffic control than do commercial air passengers.
Comment: With great incomes comes great taxes.
Comment: @gerrit Leaving aside the fact that the meaning of the word is in fact much more complex than that, the simple fact remains that there is no difference here: *The rules are exactly the same*.
Comment: @gerrit I am not sure I follow but in any case it would need to be explained and developed because as it stands your answer basically discusses the merits of having different tax brackets, which is an entirely different question. It's not even that I disagree with the points you are making but pretending this is a discrimination just creates confusion (and hiding behind a dictionary definition does not make it better…).
Comment: @DVK and now I've adapted it to also answer the discrimination question.
Comment: @gerrit - fair enough. the edit warrants removal of the downvote
Comment: @Relaxed there is no discrimination based on personal characteristics (generally speaking) in terms of paying taxes. Everyone pays the same rate of taxes on the same amount earned.
Comment: @DA. That depends.  Income from labour might be effectively taxed differently than income from capital or income from savings.
Comment: @gerrit but none of that is based on personal characteristics. Everyone is capable of having income from savings or income from capital taxed the same.
Comment: @Relaxed I rephrased the introduction.
Comment: @Relaxed the rules being the same does not prevent it from being discrimination.  It's discrimination based on income rather than on, for example, skin color.  If people were subject to a uniform rule of taxation based on the color of their skin, would you argue that it is not discrimination? A uniform rule stating that every citizen can vote whose grandfather was a citizen is also discrimination.
Comment: Another "Why" explanation that I've not seen yet in the numerous answer is that a person with an highest capital/income benefits much more from governmental expenditure: for instance, government will build airport, but poors seldom travel by plane; government will pay police to protect you from theft, which benefits you more if you have valuable goods, etc. As a consequence, it might be considered more ethical than rich people contributes more to the government.
Comment: @phoog No I wouldn't because it's obviously different. Skin colour is a personal characteristic, a rule based on it is therefore *not* "uniform" in any meaningful sense. Income brackets are.
Answer: A Progressive tax rate (meaning that the rich pay more) is typically predicated on a very specific definition of fairness that realizes:

An equal percentage is still harder on the poor.

Imagine, for example, that all people were taxed at 10%.
The guy who makes $1000 a week would only have $900 left over at the end.  That $100 is very, very precious. It can mean the difference between groceries or medicine.
The guy who makes $10,000 a week would still have $9,000 left over.  The margin increase in living standard that the $1,000 gives is far less significant than the $100 the poorer guy pays. At a certain point, one's standard of living is pretty well set.  In the case above, it might mean the difference between a vacation in Maui or Tahiti, but it isn't going to determine the same hard economic choices above.
That's the typical justification for increasing the rate as income goes up.
Comment: Why is the head fund manager allowed to keep $450,000 of his income and the person serving you coffee only $45,000? Surely that's discrimination and unfair.
Comment: As mikeazo suggested in a comment to the question this can be extended further to claim that a flat tax is unfair too.  Why is is fair that as a hedge fund manager I pay $50,000 in taxes and the person who serves me coffee only pays $5,000.  Even though they are both 10% flat tax calculations it is still unfair and discriminatory that I pay 10 times the tax just because I earn 10 times the income!  I find that a useful rhetorical argument to get people to reconsider that notion that progressive taxation is implicitly unfair but flat tax is not.
Answer: You misunderstand equal rights and are conflating people with income. The idea that everyone is equal under the law doesn't mean that the law must affect everyone equally, but that the law may not discriminate based on certain classes.
Laws against theft only affect thieves. Property taxes only affect property owners. Gas taxes and tolls only affect drivers. There are laws that only affect specific types of businesses or government agencies. Any one of the myriad parts of the tax code may or may not affect a given person. None of this means your rights have been violated, or that you don't have equal rights under the law.
But thieves are not a protected class. Property owners, drivers, kinds of businesses, or government agencies are not protected classes. None of the myriad qualifiers in the tax code are protected classes either.
Protected classes are things like race, religion or creed, gender, and (increasingly) sexual orientation, at least in the US. In the US, you can't be taxed a higher rate because of you are white, black, Catholic, Protestant, straight, or gay.
But the US doesn't have equal rights for thieves, and it doesn't have equal rights for the wealthy or poor either. So you can be taxed a higher rate because you your salary was a certain amount, or because aren't a hedge fund manager, or because your income came from wages and not investments, etc.
And about how the US income tax brackets work: Just because you got bumped in to the next income tax bracket by a dollar doesn't mean you are paying the higher bracket's rate on your whole income. You still pay the rate on the income in the lower bracket, and then you pay the rate on the income in the higher bracket. So if the tax rate is 20% on the first $100,000 of income and 25% on incomes higher than $100,000, and you earn $100,001, you only pay $20,000.25, not $25,000. That last dollar doesn't affect what you pay on the other dollars. There are diminishing after-tax returns but there is no gap where you are better off earning less. (Though I'm sure there are more obscure rules that contradict that.)
Comment: @dvk Really? Minus one because I didn't go in to enough detail on a specific point? The question was not "Please provide a full accounting of how every rule in the tax code could favor the wealthy in over of the poor or vice versa", only "If all the citizens of a country have the same rights and are equal before the law, why some must pay more taxes?" Also, I'm new here. Are these imaginary points or does they actually affect something? And how do I create a new paragraph in a comment without submitting my comment? Thanks.
Comment: +1 that last paragraph is really the key. It points out that the question is quite flawed--at least in the context of the US--where everyone *is* treated equally by our tax code (at least broadly speaking).
Comment: @JDoe - the points affect nothing of real substance, in the larger scheme of things, but are how the site gamification mechanics works. And as DA said, the last paragraph is key, in that it implies that people ARE treated the same because of tax bracket mechanics.
Comment: @DA. -1 to counteract your mistaken +1 for specifically the last paragraph. Those "more obscure rules" are majorly impactful specifically in USA, due to various exemptions, tax credits and 10000 other tax rules that dramatically affect one's tax rate based on total income (EITC being the most famous example). People earning $100k do NOT effectively pay the same amount of taxes on their first $20k as people earning 20k in practice, even though they would have if taxes were merely about brackets and rates
Comment: @dvk yes loopholes provide much complexity to the issue. At that level, the answer simply becomes "because politics" unfortunately.
Answer: Everyone pays equal taxes, and tax brackets are massively misunderstood.
The same table applies to EVERYONE:
(taken from bankrate, using 2016 numbers, and rounded for clarity)
<code>You pay 10% on your income up to  $10,000.
You pay 15% on your income from   $10,000 to  $40,000
You pay 25% on your income from   $40,000 to $100,000
You pay 28% on your income from  $100,000 to $200,000
You pay 33% on your income from  $200,000 to $400,000
You pay 39% on your income above $400,000
</code>
It does not matter how much you make, everyone follows the same table.
Some people (those who make less than $40K) stop reading the table after just the 2nd line.They end up paying an effective rate below 15%.Some people (those who make over $400K) have to read the table all the way to the end.They end up paying an effective rate approaching 30%.
We are all reading the same table and following the same percentages; The same law applies to everyone, so I don't see that as discrimination.
I think what the original question is suggesting is that every dollar be taxed equally. The law does not treat all dollars equally, some are taxed more than others; it treats all people equally.  We all follow the same tax tables, regardless of how many dollars we earned.
Comment: The only thing I'd change about this answer is it's not about stopping reading the table. It's that your value in the "income" part of the equation to work out the tax paid is 0. The whole table applies to everyone, having a lower income just means you pay 39% on the "$0" you make above $400,000.
Answer: It is impossible to answer as stated, because the answer to "does X amount to equal/unequal rights" depends on the precise wording of what the right is.
Therefore, people who favor higher taxes on the "rich", claim that the right is to have a minimal amount of money (in which case, taxing those with more than that amount violates no rights; and moreover, NOT taxing to give to those who don't have it would violate their rights).
Whereas those who oppose such an approach would claim that the right is to not have the money YOU earned taken from you by threat of force without our consent (or to not have more taken - percentage or amount wise - than from everyone else).
Both answers are correct/incorrect entirely on how you word the "rights".

The practical problem in the USA is that Constitution, as written, has very vague legal rights listed in it ("pursuit of Happiness" from Declaration of Independence).
Everything else is up for interpretation by nine dudes and dudettes on the Supreme Court.
So if the Nine decide that Constitution doesn't afford one the right to NOT have a hefty chunk of what you worked hard to earn taken from you, you don't have that right. If they decide that you have a right to a free college tuition as part of "pursuit of Happiness", you have that right.

Things get even more murky and subjective when you start dealing with "rights" as moral/ethical as opposed to legal constructs.
Comment: Actually, it depends if one means a moral right or a legal right. Legal rights are quite explicitly defined in the law.
Comment: @gerrit - moral rights are even more vague than legal ones :)  Those following Marx would have a vastly different idea of what's moral than those following Rand :)
Comment: My point was, if it's about legal rights, then it's not subjective, but well, legal. Now I was going to say that that makes it objective. The law is supposed to be objective, but actually it isn't, or we wouldn't have armies of lawyers fighting each other at the expense of, ultimately, the customer...
Comment: @gerrit - clarified that.
Answer: You could equally well ask

If all the citizens have the same rights why are some allowed to earn
  more money than others?

Sure it could be argued they earned it and therefore deserve it. But how do you determine if somebody deserves money? Money is just a social convention that says the people who possess it are entitled to change it for goods.
By the original line of reasoning you could argue that everybody should pay the same amount of tax (say $ 10 000), would that be fair? If you argue not it is probably because you think that people who have more means can contribute a little more, the same argument can be used to argue in favor of progressive rates.
I don't think there is a single correct answer to your question, but to search for it probably one should try to ask oneself what do we mean by the concept of "having the same rights"?
One generally get rich mostly by luck, and partly because of personal characteristics. Does having a little more intuition about how the stock market works really entitle you to earn 1000 times more money than the average guy. Would it really be so unjust to only let him have say 200 times as much money? (yes that would mean enforcing a whopping 80% tax rate).
It seems that the best way to decide tax rates would be by looking at the benefits for society on the whole as others have pointed out in their answers.
Update: just to be clear, I'm not saying flat taxes are necessarily bad (although I personally think they probably are), I'm only saying that they cannot be justified only on the basis that "everybody has the same rights"
Comment: Your chance of earning much is a lot smaller if [your parents are not wealthy](http://www.msd.govt.nz/documents/about-msd-and-our-work/publications-resources/research/influence-parental-income/influence-of-parental-income.pdf) you have a low IQ or are a [woman](http://en.wikipedia.org/wiki/Male%E2%80%93female_income_disparity_in_the_United_States). And your affirmation would be false in any case because tax rate is determinestically correlated to income.
Comment: @gnasher729 Only if the data sets of comparable earnings are ignored in favor of the full average, or the basic rules of economics are ignored. If women could be hired at 75% the cost of men, unemployment of women would be zero as business rushed to minimize labor costs.
Comment: @DrunkCynic That's highly debatable.
Comment: everybody has the same chance to earn money, but the "chance" to pay the same tax rate isn't the same, so your answer isn't valid.
Comment: @FelaWinkelmolen Woman have the same chance to earn the same amount of money if they made the same career choices of their male counter parts.
Comment: @AlbertoBonsanto if everyone has the chance to earn more money, then they have exactly the same "chance" to pay the same tax rate. Because as soon as they earn more money, they pay the extra tax. Changing tax rates based on income is not discrimination, because the person involved is an irrelevance. If your income changes, your tax changes, that's the same for everyone.
Answer: No government treats all of its citizens exactly the same:

A ten-year-old child is a citizen, but not allowed to drive a car or vote.
A young adult may be required to do military service; an elderly grandparent is not.
A person with a criminal record may not be allowed to hold certain jobs.
A person over the age of 65 may be eligible to collect a pension from the government; a younger person is not.
A person making $1,000,000 a year may be paying a higher percentage in tax than someone making $10,000.

The definition of "discrimination" (via Google) is:

the unjust or prejudicial treatment of different categories of people, especially on the grounds of race, age, or sex.

recognition and understanding of the difference between one thing and another.

(Emphasis added)
Obviously, the above examples are "discrimination" within the second meaning of the word. They are generally not considered to be "discrimination" within the first meaning.
Answer: There is a fundamental misunderstand of equality and discrimination implicit in the question. Equality does not mean all people are treated the same - it means they are all treated the same when they are in the same circumstances.
We are constantly treating people differently. A person convicted of a crime is put in prison and deprived of their right to liberty. That's not discrimination, as long as all people convicted the same crime, in the same circumstances, are treated the same. Likewise it is not discrimination to exclude people from (say) a concert if they don't have a ticket, as long as everybody with a ticket is admitted.
In this particular case it's not discrimination to charge people with a higher income a higher tax rate, as long as the same tax rate is charged to all people with that income (and whose other circumstances are identical).
The discrimination happens when people are treated differently based on irrelevant criteria, like race or disability. Of course it's not always completely clear what is a relevant criterion, and that's the subject of political debate.
The question also avoids a fundamental issue, which is "what makes a fixed rate more 'equal' than a variable rate?" If taxes were all fixed rate someone might well ask whether it is 'discrimination' that a person should pay twice as much tax just because they earn twice as much.
Comment: Fundamentally of course it's political question as to what is or is not 'relevant'. All I'm trying to do here is correct the assumption that because people are treated differently they are therefore 'discriminated against'. Anything more detailed is too complicated for this question.
Comment: Except that @user4012 compares a general tax rate, which has to do with income and ability to pay taxes which are both about economic standing and wealth, with a poll tax, which artificially linked the right to vote with having money, which are completely unrelated, and were put there as an excuse to block someone's rights, because they weren't allowed to do so on the basis of being black. A pretty huge false equivalence going on there.
Comment: @user4012 You state: "This answer makes a (somewhat hazily alluded to) assumption that the income level is a "relevant" criteria to how a person should be treated." Which is not the case being made. All persons are treated the same, they pay a% of tax on z income, then b% on the next y and so on. Just because the a lower earner's next chunk is 0 making the higher rater payment 0 doesn't mean someone else has been discriminated against. Taxes are the same for everyone (at least before loop holes at the top end take effect).
Comment: This answer makes a (somewhat hazily alluded to) assumption that the income level is a "relevant" criteria to how a person should be treated. You would be the first to argue against poll tax, which treats people unequally based on income; or not putting someone in jail if they are either too poor or too rich. So if you DO want the answer to be good, you need to very explicitly explain that it's predicated on the assumption that income level IS relevant to tax treatment, and **why** that is relevant from the point of view of who advocate relevance. Has a seed of a good answer, but -1 till fixed
Comment: Answer Subverts the rule of law in its insistence an absolute and equal application of the Rule of Law should be discarded in favor of a prejudicial and biased handling, driving for Equal Outcome.
Comment: ...whatever that means...
Answer: The premise of your question is wrong. Everyone is paying the exact same tax rate on their income. It just happens that portions of income in higher brackets are taxed more than those in lower ones. So for example a CEO will pay 0% on the first $50000 of his yearly income, just like a school teacher would. The extra tax is levied over income over the threshold and applies regardless of who you are, in an absolutely egalitarian fashion.
Second, your assumption that the rich are paying more tax is not fully correct. People like Warren Buffet pay a much lower percentage of their income in tax, thanks to the differences in how various sources of income are treated and the availability of offshore tax loopholes. Some billionaires pay close to 0% because they are legal residents of certain tax heavens.
Now if you're trying to ask why don't all citizens pay the same amount in absolute dollar figures, the answer is that that's the way our system works. And it works that way because it's an equilibrium that keeps most of the population happy. The rich are (for now) dependent on keeping the other 99% reasonably content and secure, so they are forced to accept paying a higher tax (in absolute dollar value) on their income. Theorethical concepts of equality don't come into play here at all.
Comment: @abelenky you pay 0% in federal taxes up to a certain income
Comment: 0% on the first $50,000!!   Very funny, but not even close to accurate.
Comment: While the key point here is correct, that the premise of the question is flawed, it's probably worth noting the inherent contradition between the second paragraph, which states higher earners pay less tax through loopholes and "so they are forced to accept paying a higher share of tax on their income" in the last paragraph.
Answer: Usually, the tax rates (no matter how simple or complicated they are) apply equally to all residents. Depending on the specifics of your situation, both the rates and the nominal amount due will differ but the rules are still exactly the same.
One one level, tax law (like all other rules everywhere) has different consequences for different people but that's trivial. If, say, the law recognizes and protects property, it will entail your right to enjoy your property and my right to enjoy my property, not my right to enjoy your property. Similarly, the penalty for murder or any other criminal offense only applies to people who committed a murder (or some other acts meeting the definition of a crime according to the law). Nobody would argue that it's discriminatory not to put everybody in jail.
When it needs to be specified beyond simplistic definitions and slogans, discrimination means something else, namely treating people differently based on some irrelevant personal characteristics. Thus, the laws or treaties that forbid discrimination usually include a list of such characteristics (origin, gender, race, religion, etc.)
Now, there are a lot of debates on the merits of various ways to structure, e.g., income taxes. For example, proposals to introduce a "flat tax" with a single marginal tax rates for all incomes are quite popular. But it's not clear that thinking of this in terms of "discrimination" is very useful or makes sense at all.
Answer: Governments, whether they be monarchies, dictatorships, democracies or communist have a common goal in promoting the safety, well being and overall good of the people.
Often this means that certain groups will be targeted for taxes or benefits to promote the general common good.  Many people believe that a strong social safety net reduces economic volatility and provides for a better quality of life overall in a modern capitalist country for nearly all involved.  The security of knowing that when faced with hard times that you will not starve or become homeless due to a few bad breaks in life is often reason enough to support public unemployment compensation, social security, welfare, food stamps, and even public healthcare.  These are extraordinarily expensive however so taxes must be raised to pay for these things.
Furthermore it can be argued that a strong social safety net has a positive effect on economic growth, as the consequences of a failed business venture are not quite as extreme when you know that your family will not starve if you take out a large loan for an unsuccessful business or startup.  These kinds of policies promote economic growth and support small businesses ultimately.
On the point of fairness, there are a number of taxes that are inherently unfair yet are politically very popular and easy to implement.  "Sin" taxes like the exorbitant taxes on cigarettes and alcohol are a prime example of ones that target a specific group because it is politically easy to target them.  Nobody wants to look soft on tobacco or seem like they are promoting alcohol, so few oppose such taxes and the majority of people support it because these are inherently sales taxes and are mostly transparent to the uneducated consumer.
With that being said no we address the fairness, that if all people are equal before the law and all have the same rights as citizens, we are certainly not and never will be all equal as individuals.  I may have been born with innate advantages in life, born into wealth or perhaps I am Bill Gates (who consequently was in the very least upper middle class as a child) and made a few lucky breaks and was in the right place in the right period of time.  The fairness argument above can also be said that the opportunities available in this country, and the rights that our government and military have protected for us make it fair for the government to ask for a little bit more from people who would not be terribly pained by this.  Asking a little bit more from somebody who is living paycheck to paycheck is an enormous burden on that person.
So in the benefit of the common good we can make a number of arguments to justify if higher taxes on one group of people is fair.  Certainly not in all cases, but the argument can be made that it can sometimes be fair.  But then taxes are not just a means to gain income for the government, they also happen to be a convenient way to encourage behavior in citizens that benefit the economy and strengthen its people overall.

Lower capital gains vs. income tax/estate tax:  Having a higher income tax or estate tax rate as compared to capital gains income encourages the wealthy to not only invest their money but to keep it invested rather than sit on it.  More investment helps the economy grow.
Sin Taxes: Discourages behaviors that affect public health and cause higher healthcare spending overall as a percentage of GDP.
Mortgate Interest Deduction: Encourages home ownership in the middle class.  Housing starts are the primary indicator of a health US economy, and so goes the world.

So taxes (or high taxes with loopholes) may seem unfair, but if one believes that the ends justify the means then the benefits of influencing good economic behavior and promoting overall economic growth justify that decision.
Comment: -1, because this whole write-up basically amounts to "if I (not you) judge that you can afford to pay more, then taking more from you is NOT unfair". Following the same logic, someone who was born good looking and good at attracting romantic partners can afford to share them, so it would be fair to legislate that the shy and not-so-goodlooking people would be legally allowed to have sexual access to the good looking ones.
Comment: "for a little bit more from people who would not be terribly pained by this.". Typical platitude that plays to the masses and sounds good until the people realize that they themselves are those people being referred to as "who would not be terribly pained by this". They then realize that they most certainly are terribly pained by this. Plus, the very wealthy tend to be in situations where they can pass their increased taxes onto the poor. Thereby causing more harm to the poor than any help that the increased taxes could ever provide. Everybody is worse off.
Comment: Well, sin taxes (at least, tobacco) aren't as unfair as they seem - most of those sins have negative effect on the economy and carry costs to society not paid by the sinners.
Comment: @DVK that's why in The Netherlands, people with severe disabilities (in permanent care etc.) often do get access to subsidised prostitution, because the government recognises that sex is a basic human need.
Comment: Nope, this is rather for people that are e.g. in a wheelchair their entire life, maybe paralysed below the neck, that kind of thing. I think they assume that if you're simply not a ladies man, you'll find your way to the Amsterdam red light district on your own (assuming you are not too disabled to get a job and earn some money to pay for this).
Comment: @gerrit - if they include "not a ladies' man" into the list of disabilities, my next question is "how do i apply for citizenship" :)))
Comment: @DVK I think you misunderstand me, it can and sometimes certainly is unfair.  I was merely presenting arguments that support the notion that is SOMETIMES fair, especially considering precedents, and if you believe that the ends can justify the means.
Comment: @user4012 Cosmetic surgery is covered under many circumstances, if the cost is reasonable, then there's no reason not for the surgery to be somewhat proactive instead of just reactive.  For example, a birth defect like a cleft lip is mostly fixed even when it's mild enough not to cause further medical problems.
Comment: @algid in this context, people rarely if ever consider cleft lip in the category of cosmetic surgery {nor burn fixing} even if they technically are.
Answer: The difficulty with this question is that it's trying to make a connection between the rights of citizens and tax codes.
They're not necessarily all that related.
In the US, for instance, as several have pointed out, one's "rights" don't typically mention anything about tax rates.
As for being seen as equals in the eye of the law, again, that's typically in the context of one's rights. (And I would also add that not every nation believes in treating everyone as equals in that sense, either.)
As for it being discrimination, at least in the legal sense, I don't know of any nations that have codified the idea of discriminating on income levels as being prejudicial. Some examples of what legal discrimination can be: http://en.wikipedia.org/wiki/Discrimination#Caste_discrimination
As such, the question really can't be answered as it's worded.
You could, instead, ask "why are there different tax rates?" which would be a valid question, albeit one with rather complex answers that likely vary wildly from nation to nation.
Comment: Actually, if you think about it, within tax there is no discrimination. Whether you're black or white, male or female, you pay the same tax if you earn the same amount of money.
Comment: @sgr yes, exactly.  There is no discrimination in the legal sense.
Answer: All people are eligible to pay the exact same taxes if they are in identical circumstances.  Anyone earning $1M dollars AGI, with $13,000 in mortgage interest, $8000 in property taxes, $65,000 in state income taxes, with three children is going to owe the exact same amount of federal income tax as anyone else in the same situation.
Anyone earning $45,000, with no mortgage and $3000 in state and local income taxes will owe the same amount as someone else in that same situation.
The person earning $45K should not owe the same amount or even the same percentage as the person earning $1M because their situations are not the same. Treating people who are in different situations differently is not unequal treatment, it's unequal circumstances.  If the person making $1M this year only makes $45K next year, he will owe the same rate as anyone else who earned $45K, and if the person who made $45K this year makes a million, he will owe the same as others who are making $1M, so it is completely equal treatment.
Comment: @DrunkCynic - not sure why you're asking. Why are completely different situations treated as different?  Because... they **are** different. Why should they be treated any other way? Why is rape illegal, but consensual sex not?  Because they're not the same. I could, literally, go on forever. Could you please explain what it is you're asking, exactly?
Comment: Why are speed limits different on the highway than in school zones?  Shouldn't we drive the same speed everywhere?
Comment: Why do differing situations have differing protections from the law?
Answer: Every answer so far has assumed the question was directed at something like tax brackets (which I admit it probably is), when instead it's been phrased perfectly to suggest that anything aside from something like a universally equal lump sum payment is discriminatory.  The question could be referring to deductions, subsidies, income types or wealth, while not bothering to state what equality would mean.  It's really not very coherent for any number of reasons.
People have already answered along the lines of income and wealth not being a protected class or the marginal utility of money decreasing as the amount an individual has increases (neither of which are controversial political/economic positions), so I won't be repeating their points.  I'll instead try to answer things along the lines of equality when looking at things from the perspective of government services consumed.
Even in some sort of theoretical Libertopioa, I would assume that the government still holds a monopoly on the use of force.  If we assign a value to human lives based on some combination of income and wealth, then those with a higher income or wealth experiences greater value from the government monopoly of force and the resulting safety of their lives, sources of income, and capital in direct correlation to the increased value of these things.  For example, if a homeless vagrant is murdered, he loses the total of his wealth (hundreds to thousands of dollars maybe?), and his projected future income (have to consult an actuary for the specifics, but probably not an impressive number).  If instead a millionaire is murdered, the loss of his wealth and future income could easily go into the hundreds of millions or even higher.  I would think this is simple enough to establish something like a tax that varies based on income and wealth even if you view tax as a payment and the monopoly on force as a service.
Similarly, in a normal society, people with high income and wealth consume other services not available to those with less income and wealth.  For example, the use of public roads is dependent on ownership of a motor vehicle.  To extend that even further, the operation of a business could depend on things like transportation of goods on public roads, a pool of educated and healthy laborers, and a wide consumer base with a level of income necessary to enjoy their product.  An increase in the tax rate as income or wealth increases can reflect this increase in the consumption of services.
Comment: "Every answer so far has assumed the question was directed at something like tax brackets" - not true.  In my answer - "The person earning $45K **should not owe the same amount** or even the same percentage as the person earning $1M because their situations are not the same."  To be fair, there was a lot out there to wade through, from everyone. Just letting you know that that absolute statement isn't entirely accurate.
Answer: I think there are tree factors to this.

First, by-person taxation would create very great pressure to the poor, depriving them of many basic needs. The poor people spend much greater proportion of income on their food and other basic things. The rich people will not even notice such taxation (as it will be negligible compared to their income), which effectively would mean that the rich are tax-exempt.
Second, the rich people consume much more state services per person than the poor: for example they need more police and army to keep their wealth in safety. Being rich in a country without law is useless: any bandit criminal group will easily take your possessions. The more state services are consumed, the more they have to pay.
Third, from Marxist perspective, there is income from labor and income from expropriation of surplus value. The rich people most likely acquired their wealth through theft of surplus value from the workers, while the workers were already "taxed" by their employees who took the surplus value. As such, the state should take that theft wealth from the rich and return it to the workers in form of state services.

It should be noted that in Socialist states where all the enterprises belonged to the state, nearly all legal income (except lottery wins and the like) was due to labor. In such circumstances there was no real purpose in taxes. Indeed, the "taxes" were negligible in the USSR (one can really wonder why they were at all if they were so low).
Answer: Much has already been said regarding tax and rights. So, I'll simplify:
The government does not tax people, it taxes money. Think of tax as a fee for management of money. Consequently, any person or institution that has more money will correspondingly pay more money in taxes. Its that simple!

Analogy:
Think of two neighboring families (Millers and Smiths) visiting an amusement park. The head of the family pays a flat fee for his or her entire family. Millers are just the couple and Smiths have 5 kids in tow. You could argue that both should pay the same fee for their family, since a family is being charged. However, the amusement park charges the Smiths with 7 people more than it charges the Millers with just 2 people.
However, the difference in charges isn't a simple ratio of the size of the families. The amusement park reserves the right to maximize their profits and in so doing will create a fee structure that maximizes the number of people that visit them. Therefore, the fee structure will be based on several factors, among which is obviously the operational cost to the park for each guest.
Typically, they will choose to charge a family of 1 i.e. single person very little since single people need incentives to visit the park and would otherwise not visit. (For example) They would stratify fees in layers for families of sizes 3, 5, 7, 8 or more.

A government will create tax laws that it feels is in the best interest of the country towards stimulating economic growth of the country as a whole. Countries have different tax structures based on their policy regarding economic growth. There isn't a universally acceptable tax structure and it has no correlation with human rights in principle.
That leads us to the final aspect of the question: Can tax laws potentially discriminate and/or abuse human rights? Yes, they can if the imposition of tax rate is based on factors other than total income. Other forms of discrimination in practice, though not in principle, is the consistently biased selection of some people (rich members of a minority) for auditing. However, this and many potential forms of discrimination in imposition of taxes do not make the principle of stratified tax rate proportional to income itself, discriminating.
Answer: The problem is... The progressive tax system is usually (details vary from country to country) completely undermined by various deductions, often related to the ability to accrue debt, which again increases with the amounts of collateral you can put up, which again follows how 'rich' you are.
This means that the wealthy usually end up paying a lot less than they should, usually even less than the average 'poor' citizen.
This is why a completely deduction-less fixed tax system in reality would be more fair and provide more tax revenue than the current implementations of progressive tax systems.


Infinite Union operation of Formal Languages

Question: Is every formal language  not closed under infinite union operation ?
I know that Regual Languages are not closed under infinite union operation and I have counter-example for it but I don't have any counter-example for other languages. Intuitively , I think it should not be closed but intuition could be wrong also. So please clarify whether every language (like DCFLs,CFLs , Recursive , Recursively Enumerable)  is closed or not under infinite union operation.
Answer: Virtually every standard language class contains singleton languages, e.g. those languages containing exactly one word ($L_w = \{w\}$).
If a class containing every $L_w$ were closed under infinite union then it would contain any arbitrary infinite language $L$ since
$$
L = \bigcup_{w\in L} L_w
$$
More in general, we can write any language (finite or infinite) using an infinite union of singletons or empty languages.
$$
L = \bigcup_{w \in \Sigma^*} \{w\ |\ w\in L\}
$$
where $\{w\ |\ w\in L\}$ is $\{w\}$ when $w\in L$ and the empty language otherwise. (I wish set comprehensions had a standard notation for free and bound variables! Here, $w$ is free.)
Answer: Languages aren't closed under operations; sets of languages can be.
The set of all languages is closed under infinite union.  So, the answer to your question at the start of your post is "no".
The set of DCFLs is not closed under union, so not closed under infinite union, either.  For the rest, see Infinite Union of Recursive language, Is an infinite union of context-free languages always context-free?, and Infinite union of recursive languages.
Answer: To add a more concrete example to chi's answer, in the case of CFL's, think about the following infinite union:
$$\bigcup_{i=1}^\infty\{0^i1^i2^i\} = \{0^n1^n 2^n|n>0\}$$
which is a known example of a non context-free language.


Changing seats in a Texas Holdem game

Question: Can a Texas Holdem player move from a seat into another seat that has the little blind or the button under any conditions, such as, posting the blinds?
Comment: If you want more specific answers to certain scenarios that my answer doesn't cover please let me know and I can try to answer.
Answer: Yes you can always move to any empty seat, but often with minor consequences. Rules vary from place to place.
Almost every place you cannot receive a hand if you move to the button. You cannot receive a hand in the small blind and then receive the button next hand. You cannot take the small blind. *You cannot move to an empty seat between the button and the blinds and receive a hand.
In some houses, if you move away from the blind you must post a blind or wait a number of hand(s) that corresponds with the number of seats you moved. *Some places will let you post between buttons and blinds.
The rules about the consequences of changing seats almost always vary to some minor degree from casino to casino. Go with what your dealer says.
Answer: In a cash game, yes a player can move seats if a seat is open. Different places might have some different rules, some places might not even allow you to move to a different seat on the same table, but may allow for a table change.
In general from what I've seen players can:

Move to the button no problem if that seat is open
Move to the big blind no problem if that seat is open
I've never seen anyone try to move to the small blind, but I would imagine, and I would do this as a dealer, make them post the bb to.

In a tournament, no you cannot move seats, unless the TD moves you as a player, in which case you will have no say on what seat you get.
In the case of a tournament and being moved:

If you end up on the BB or the button, you get cards and continue as normal
If you end up as the SB you sit out a hand and there is a dead SB

Changing seats in a Texas Holdem game


Accidentally left car idling for 14 hours. What are possible consequences from this?

Question: I have an 08 ford focus that I haven't been driving. I just turn it on and let it run for about 30 minutes every few weeks so that it's not just sitting. One time I left it running in the parking lot and forgot about it until 14 hours later. How bad is this? What kind of damage could I expect from this?
Comment: Just curious, how much gas did that use?
Comment: Aside - this doesn't help your tyres avoid flat spots, nor does it help the gearbox or clutch.  For some vehicles that depend on splash lubrication in odd places like swivels, there won't be any.   Best drive for about 20 minutes.  You don't have to get out of the car elsewhere.
Comment: very importantly: if someone does the same but in a garage, or any enclosed area (and this can happen also with a badly running furnace, etc) : https://www.abe.iastate.edu/extension-and-outreach/carbon-monoxide-poisoning-garages-aen-207/
Comment: it didn't run out of fuel surprisingly. It only burned through about 5 gallons.
Comment: Did it run out of fuel, or did you discover it and turn it off before it ran out?
Comment: @Mike That's quite high consumption at idle, with a warm engine you should get to about 0,5l (or 0,15 gallon) per hour. Something is not right. Hopefully it's just the fact that you start your car cold and leave it idling - others have already pointed out that it's not good at all for your car to do that.
Comment: possibly you'd run out of gas.
Comment: @Mike I don't see why this is surprising. By far the biggest use of gas is making your 1.5 ton car move. That's a lot of work that requires energy from the gas. If it's just idling, it shouldn't use much gas at all.
Comment: @JasonGoemaat By my math, it was using  ∞ l / 100 km.
Answer: There's probably no damage at all, the engine just ran at low revs for a long time. One issue you may have is if it ran out of fuel the line may have sucked sediment from the bottom of the fuel tank and drawn it into the fuel filter, which can clog the filter up. If you notice it's lagging a bit in the future what's what I'd look at. Fortunately fuel filter replacements are cheap. Also, some fuel pumps are designed to sit in the fuel tank and be cooled by the fuel, running very low on fuel could overheat the fuel pump, this could also lead to insufficient fuel pressure, especially at higher revs, however it's unlikely a single instance would cause that much damage.
Incidentally, just letting your car idle isn't good enough, you need to actually drive the car around to keep everything working and the tires circular. A 20 minute drive once per week will keep the battery charged and everything working.
Comment: @zipzit Police cars at least used to have things like better alternators and more cooling in order to support that use case. (Agree once isn't going to hurt anything much, but to do it all the time like police cars do--better build for it.) https://auto.howstuffworks.com/police-car2.htm
Comment: Why do people always go on about "when the fuel in the tank is low it might mean the fuel pickup pipe sucks sediment up" - where do they think the fuel pickup pipe is the rest of the time (when the fuel is not low) ?
Comment: Great answer.  Funny, look at the drive cycle of Police cars.  In some cases those engines run essentially 24x7, often for long periods of time at engine idle.
Comment: So suction is some kind of mystical force that spreads throughout a liquid, and when there is less liquid, the suction is less spread out so you can pack more suction in per cubic inch, and it does a better job of picking up sediment? Does that even *sound* believable to you? People who assert this should look at how a fuel tank is designed, and how modern fuel injection system works
Comment: Sounds like a process that affects cars constantly, especially those driving around/slopping their tank contents around in a continual shaking - so why aren't the streets littered with broken down cars everywhere, blocked fuel filters abound. If a tank contains half a pound of crap, it contains half a pound of crap, and if its suspended in the fuel it will eventually make its way up the pickup pipe and into the filter. The volume of fuel in the tank is immaterial to this process. I also disagree with your assertion that a blocked filter filters worse than an unblocked one.
Comment: ..a moving car both. For this answer to assert the main damage done to the car will be to the fuel filter "by running the tank low causing more crap to go up the pickup" is BS IMHO. I challenge anyone to find a trough of water with plenty of sediment on the bottom, start a 0.5l/hour siphon (let's mimic the burn rate of a vehcile) and tuck the pipe into the corner of the trough. You won't see all that crap on the floor of the trough mystically whoosh up the siphon pipe when the water level gets low; it'll stay put
Comment: Police cars usually have two batteries, too, to support all the electronics inside
Comment: A fair question @CaiusJard. With a partially full tank there isn't enough suction to pull all the sediment, when the fuel is very low suction is concentrated into a small volume of fuel and so it has much more power to pull heavier sediments in, which otherwise wouldn't be disturbed.
Comment: I'm not saying that clogged fuel filters don't happen; I'm asserting that running a tank low isn't magically going to make a stationary car with a fuel tank full of crap block its fuel filter whereas driving it round with that same fuel tank full of crap sloshing around will make the crap magically avoid the fuel pickup pipe. Fuel injected cars constantly return filtered fuel to the tank and constantly pick up unfiltered or screened fuel. Of the two types of crap you might encounter in a fuel tank (suspended in the fuel, settled on the bottom) a stationary car is going to pick up one...
Comment: @CaiusJard - Sediment (used as a generic term for whatever might be in the tank which isn't fuel) can be suspended in the fuel, or dispersed around the bottom of the tank. As the fuel becomes lower, the sediment becomes concentrated more and more. If the pump screen becomes more full, there is a propensity to pull in more of the sediment and cause issues. This can either plug the screen, or if it gets past the screen, can plug a fuel filter and cause damage to the fuel pump. Think of how much crap can end up in your fuel tank over a few years of fill up w/ bad fuel ... this can and does happen
Comment: @CaiusJard I understand - like I said, I'd be surprised if an analysis showed that to be a leading cause of fuel filter plugs.  I was specifically responding to your somewhat sardonic statement about a "mystical force" that is more effective at picking up sediment at lower levels.  I'm saying there is definitely an effect that would be understood thusly, even if this doesn't apply to fuel tanks of current design.  Incidentally this also applies to sump pumps deep in a narrow sump, the bathtup was just a reference to something people are familiar with.
Comment: @CaiusJard Maybe they're speaking from experience, of having had problems after running out of fuel? Just a guess.
Comment: @CaiusJard, clogged fuel filters and how they get that way aren't just a matter of opinion. It definitely happens. https://cartreatments.com/bad-fuel-filter-symptoms-replacement-cost/
Comment: @CaiusJard I share your skepticism about this being so common a cause of clogged fuel filters that it is mentioned almost every time low fuel level is discussed... however, there is a very plausible mechanism for sediment pickup to increase as the tank goes empty - the volume of fuel entering the pump is the product of the cross sectional area through any loop around the pump and the velocity at the loop.  As the tank level decreases, the cross-sectional area decreases, so the velocity must go up.  Sediment pickup is a function of velocity.... The same thing happens when a bathtub drains
Comment: @JoelKeene If a fuel tank were shaped and designed to be drained anything like a bathtub/at bathtub rates I might agree, but the internal design of a fuel tank and the positioning of the pickup/return system necessary to prevent pickup starvation when a car travels on an incline make this "fuel is low so all the tank sediment suddenly whooshes up the pickup" claim all but impossible, especially within the context of the question
Answer:
I have an 08 ford focus that I haven't been driving. I just turn it on and let it run for about 30 minutes every few weeks so that it's not just sitting.

Don't. Idling an engine is the worst way to warm it up. Also, if you do this because you want to keep the battery charged, the charger may not be able to produce as big current when idling. It's good to let all parts including tires move, so instead of idling it, please consider driving it for the equivalent time. The increased costs due to fuel consumption is more than outweighed by the reduced risk that someone steals the car.

How bad is this?

It's bad. Two risks can happen:

The car can get stolen.
If the cooling system is not up to the task, the car can overheat -- especially if the fan doesn't work. Normally the fan is not needed due to air current as the car is moving, but when idling at standstill it's a different game.

What kind of damage could I expect from this?

If it didn't get stolen and didn't overheat, you're probably fine. As GdD explained, it's not recommended to run out of fuel, but you didn't mention running out of fuel.
Comment: Assuming you have a second key and lock the doors while it's idling, the increased risk of theft is not all that high.
Comment: Alternators are designed to put out plenty of power to charge your car at idle speeds. You're only going to run into issues charging at idle if you're also powering a massive aftermarket sound system or other non-standard electronics.
Comment: Don't forget that (possibly in this case but definitely in a lot of cases) with wireless keys it's possible to walk away from the car having started it with the presence of the key, then leave it idling, locked with no key inside and the computer beeping away saying "key not present". It's still driveable, and if a thief steals it and stalls it they might have a problem, though some cars will allow restart of a stalled car within a certain timeout even if the key is absent..
Comment: @R..GitHubSTOPHELPINGICE Depends on the neighborhood, right? I can think of some neighborhoods where "just break a window and drive away" makes a difference. Maybe some cars, too, if you have one that has the fob transponder, etc., so it's a huge pain to drive it away without the key--but your windows are still easily breakable. (Plus you put a sign on your car saying the key is there, since people can hear it running.)
Comment: This. And don't forget about the toxic fumes that are the result of inefficient combustion.
Answer: Short response:
No damage - idling a car does not hurt it.
Long response:
That said, you shouldn't be idling it to warm it up/charge the battery/whatever.  What I do with my cars in storage is put the battery on a tender.  Then every two weeks or so, turn the key on to unlock the transmission (key on, not start), put it in neutral, and roll it a few inches.  This fights flat spots and keeps the battery charged.  If you can't hook up a tender (as you mentioned a parking lot), then I recommend keeping the battery somewhere with adequate airflow (such as a porch or patio) and keeping it on a tender there.
Keep in mind that most of the wear on an engine occurs when it's cold.  So starting it just to move it a few inches isn't good.  And idling it rather than driving it means that it stays cold for longer, thus extra wear.  There are also other concerns if the engine doesn't heat up enough on a regular basis (when the car is started and doesn't get up to operating temp).  Not starting it at all is the best way to 'preserve' it.  I'd say drive it every 2-3 months to be safe, but I've gone 6 on mine without any issues.
Make sure you're still changing the oil as recommended even though it's being stored.
Comment: Well, change the oil once maybe.. But if you're gonna lay up a car for eg 5 years I don't see the point in changing the oil every year, when the engine is never even started
Answer: Prolonged or repeated idling can cause coking and sooting of the cylinders and plugs. This can make it hard to start,  taking it for workout for 30 minutes or so will clean that up.
Comment: From what century is the vehicle to which this answer relates?
Comment: @CaiusJard modern cars suffer, too. Esp. in cold weather.
Answer: No severe damage has been done to your engine except for the fact that due to idling for a long time, a little bit of carbon deposits have been developed inside your combustion chambers. You can remove them by driving your car and revving the engine a little bit to increase the pressure inside cylinders and burn unwanted deposits.
Never let your car idle for more than a few minutes because during idling, combustion doesn't happen efficiently and blow-by is high because there is not enough pressure to seal the piston rings against cylinder walls. Too much blow-by will dilute your oil and diluted oil will not be able to lubricate your engine properly.
Blow-by means the amount of combustion gasses and combustion byproducts that go past through the gap between rings and cylinder walls. They will enter into the oil sump.
Comment: Could you please provide a credible source of evidence for your claim of *"during idling ... blow-by is high because there is not enough pressure to seal the piston rings against cylinder walls"*?
Comment: During idling, incomplete combustion happens and this is a major factor of oil dilution. Moreover, according to the following source, one supplier of blowby flow meters said contrary to what many people think an engine typically has more blowby at idle than at higher rpms. As the speed goes up, the rings actually seal better and blowby drops. Therefore, this source also refers to the fact that at lower engine speeds, ring sealing is less effective. Here is the source: https://www.aa1car.com/library/engine_blowby.htm
Comment: So the bit where you asserted that it is cylinder pressure that causes a piston ring to seal against a cylinder wall is your own fabrication?
Comment: revving the engine doesn't increase pressure much.  to increase pressure need to open throttle and not have the engine race.  eg hill climbs in a steep gear,
Comment: Fabrication?! I don't know what you are up to but there are also lots of sources for this fact like this one which says: Combustion gas pressure forces the piston ring against the cylinder wall to form a seal. https://courses.washington.edu/engr100/Section_Wei/engine/UofWindsorManual/Piston%20and%20Piston%20Rings.htm
Comment: Yes, Jasen. Increasing engine load increases cylinder pressure and cleans combustion chambers.
Answer: Idling a cold engine is bad for the engine itself and bad for the environment. The simple fact that the engine is not on its target operating temperature means that combustion is only partial and toxic fumes are emitted and the internal parts and oil are polluted.
Just like the others mentioned, you should drive the car. All parts need to move and tires need to roll.
Answer: Consequences to the car: None. Consequences to people near, if it inside a garage or closed place: Asfixiation by carbon monoxide.


Reading Data From MS Excel in .net

Question: I have written a piece of code that reads excel data in data table through ado.net. Now i have seen a strange behavior, That the column data type in ms excel is specified as general, but if the 1st row of the excel of that particular column contains some text, ado.net is unable to read numbers in that particular column and if 1st row contains some numeric information ado.net is unable to read textual data of that particular column. here is the code i am using to read data from excel.
<code>    string excelConString = @"Provider=Microsoft.Jet.OLEDB.4.0;
                                Data Source=D:\A.xls;
                                Extended Properties=""Excel 8.0;HDR=YES;""";
    var oleDbConnection = new OleDbConnection(excelConString);

    var cmd = oleDbConnection.CreateCommand();

    cmd.CommandText = "select * from [WorkSheet$] where ID>=1500";

    OleDbDataAdapter da = new OleDbDataAdapter(cmd);

    DataTable dt = new DataTable();

    da.Fill(dt);
</code>
Any help would be appreciated.
Regards
Ahsan Iqbal
Comment: Have you tried adding MAXSCANROWS=0 to your extended properties in the connection string?
Answer: change your connectionstring to
<code>string excelConString = @"Provider=Microsoft.Jet.OLEDB.4.0;
                          Data Source=D:\A.xls;
                          Extended Properties=""Excel 8.0;HDR=YES;IMEX=1;TypeGuessRows=0;ImportMixedTypes=Text"""
</code>
Comment: make HDR=NO - that should help

Reading Data From MS Excel in .net


Is it advisable to use global variable in smart contract?

Question: I know we can use global variable in our smart contract. So, How can I make sure that nobody can access my global variable.
Answer: Global variables are more or less a design thing. I personally do not like them because of object-orientation for languages like c++. They are good for script languages, but if your application or contract gets complex, things get complicated and they are hard to maintain.
However you do not have to worry about access of our global variable because of the application isolation of the WebAssembly virtual machine. Also they only are accessibly during your action excecution. Your contract code/variables/members will be reinitiated on every action call. If you want to persist your variables you have to use the multi_index (aka Persistence API).
It may be possible to store abitrary members/attributes of your contracts in the table if you select a fitting table schema. Maybe something like this:
ID (unint64_T) | Attribut (String) | Value (String)
0              | 'mCounter'        | '5'
1              | 'mComplexAttribut'| '{ key: 1, key2: {...}}'

Answer: Global variables should be used sparingly in C++ programs and only used when absolutely necessary. It's good practice to keep variables limited in scope (using keywords static, private, etc) to protect unintentional modification of their value. You can create functions to allow modification of these private members from other parts of your program.


How do aircraft go off-course even with all their guidance technology?

Question: Pilots today have more than enough technology both in the cockpit and in the infrastructure that supports them to know with great precision where they are at any given time. How/why do they still sometimes go off-course?
Comment: They enter in others space because they want to. They know they are in.
Comment: @mins Would it have made any difference if I phrased my question as, "How would it be possible for aircraft to unintentionally enter another country's airspace?" Because that is essentially what I am asking.
Comment: Are you also interested in the vertical navigation error (altitude error)?
Comment: Haven't seen all the details from this one, but last time we've seen two conflicting accounts of what happened. Did they cross the border? Did they not? How far? How long? Unless you were actually on site with the right equipment to precisely determine the position of the aircraft at all times, it's just wild speculation on who is right.
Comment: @mins It is not a political game. I can accept that the vast majority, if not all, of modern airspace violations are intentional, but voting to close without the slightest attempt to explain technically how unintentional violations *could* happen or why they *should not* happen is a total non-answer. My question is not meant as flamebait.
Comment: I edited the title and removed military references.
Comment: The new phrasing of the question is a bit too generic IMHO... Reference to specific cases would narrow it down (there are many possible causes for going off-course, from intentional, hijack, incorrect info, problems with instruments, crew incapacitation, inattentive crew, sleeping crew...).
Answer: 1) Technology is fallible.
2) Humans are fallible.
Now that aircraft have GPS receivers it is rare for them to be off course by a considerable margin. That said, technology can fail and there are cases where the GPS cannot, or should not, be used.
The crew can also make mistakes, either by incorrectly reading the navigation data or by incorrectly entering flight path details into the navigation system: An aircraft may actually be 'on course' based on what the crew told it to do, but they told it the wrong thing. Depending on how data is entered into the system it's easy to add the wrong waypoint (some have very similar names, there's been a few cases of that happening) or to enter reciprocal bearings or lat/lon points.
On top of that there's simple crew distraction - if they're manually flying then they may be focussing on something else and not notice that are off-course: As happened on the Sukhoi superjet demonstration flight a few years ago.
Comment: And to add to #2... people will sometimes hand fly the aircraft and just flat out forget to look at the map: sometimes if they think they know where they are but are in fact in a very similar looking area. I've done this when driving before I realised there are two very similar looking churches next to two very similar looking garages...
Comment: @Pedro - ask another question! Sounds like a valid one to me.
Comment: @ Simon: in your great answer you mention crew distraction as a possible cause of getting off-course. Not sure if it's always to be called distraction. After all the golden rule is first flying the aircraft, which can be quite a job sometimes. Then comes navigating it. (And then communicating.)
Comment: @RobVermeulen: Yes, that's a good point. To be honest 'distraction' was simply the best word I could think of to describe this. Flying might be most important, but it is still a distraction from the navigation task :)
Comment: Thanks for the answer. I would be interested in knowing in what kind of situations GPS is not recommended.
Comment: @Pedro - another question regarding GPS is better I think. Whilst linked to this question it raises a number of different issues that aren't relevant to this answer.
Answer: The navigation data (angles, coordinates) are initially numbers and must be read by human first to use the navigation systems. If the pilot misreads or wrongly interprets the initial data, the navigation tools cannot help.
This seems the reason of both Varig Flight 254 and TWA Flight 3 navigation mistakes. In general cases seem rare as they require the navigators to stay disoriented for a long time, regardless of that they see, radio stations they hear, etc, etc.
Answer: My Dad was a fighter pilot in the Korean War. He acidentally did something in the cockpit which effected his air mix. Without sufficient oxygen, my Dad got lightheaded and started flying towards North Korea. My Dad might well have died or become a POW except that members of his fighter group flew back to find him. My Dad was sufficiently cognitively aware to recognize his comrades and use them as his "navigators" back to home base.
Things that can effect a pilot's cognitive state can still happen. Look at naval and air force fighter crashes over the past handful of years. As a chemist, I'd identify one likely culprit as new cockpit materials insufficiently tested for offgassing (changed chemical state) at critical state points. I have one material, in particular, in mind.
Comment: Out of curiosity, which material and why?
Answer: A basic expansion of os1's answer.
1) broken or defective equipment.
2) equipment that is not properly maintained or calibrated.
3) improper use of equipment by flight crew.
4) incorrectly interpretation of output data from equipment by flight crew.
5) terrestrial or satellite navaids needed to operate equipment either down for maintenance or unavailable.
6) incorrect procedures used by flight crew.
7) Overconfidence in onboard systems causing negligence of basic airmanship and good risk management.
8) Confusion among duties for pilots in aircraft requiring more than one flight crewmember.
9)  saturation by existing cockpit tasks causing negligence in navigation.
10) human frailty, fatigue and external pressures.
It can happen to anybody, in any kind of airplane, no matter how advanced the equipment on board is.   I wrote in a post about Instrument flying that modern integrated flightdecks i.e. glass cockpit have the capability to make a good pilot better and a poor pilot dangerous.   This still rings true today.   Smart people routinely do stupid things in aircraft and it can have tragic consequences.   This can be insidious if one is not careful.


If you are listening to someone praying outloud And you say Amen.Did you just pray?

Question: If someone is listening to another person praying out loud, and they respond, "amen," does Hashem consider the response to be a prayer in its own right?
Comment: Please edit / modify your question to reflect your last comment. As you can see, the answer, below, may not be answering your question.
Comment: You may have to narrow the focus of your question. By prayer do you mean "blessings"? E.g. - a blessing is required before eating food. If someone else makes a blessing on the same food, aloud, and you answer "Amen", it is as if you had made that blessing. I am not sure this principle applies to answering "Amen" to the blessings that part of the Chazzan's repetition of Shemoneh Esreh, even though that was the original intent of having the repetition. I'mnot sure if that rule still applies. It doesn't apply to certain other mitzvoth e.g. wearing tefillin.
Comment: @DanF Thats true I did not think about the food part.But if someone is praying for a new car or healing or whatever,and you say amen.Did you just pray also?
Comment: well the answer below was interesting,still maybe an edit would help,but I do think the question is clear
Comment: possible dupe http://judaism.stackexchange.com/q/19125/759
Answer: Hashem does consider it a prayer, and it is considered to be the same prayer recited by petitioner.

Whenever a person listens to the entire recitation of a blessing with the intention of fulfilling his obligation, he is considered to have fulfilled his obligation although he does not answer Amen. Whoever answers Amen to a blessing recited by another person is considered as if he recited the blessing himself, provided the person who recites the blessing is obligated to recite that blessing.

Rambam, M"T, Hil. Berakhoth 1:11
Comment: very interesting
Answer: An extension of what you refer to is the Shome'ah K'oneh (One who listens is considered as if he answered.) principle. This is mentioned in Bab. Talmud Succah 38b.
It is generally suggested that a person who answers Amen is considered as if he said the blessing. This principle is used in mitzvoth such as Megillah reading and listening to the shofar. (Note in particular regarding Shofar, that the shofar blower says in the blessing "To hear the sound of the shofar." This, obviously, includes himself.)
The Talmud page (see also Rash"i as well as Tosfot commentary, there) state that even if one merely listened but paid attention to the prayer / blessings, and did not respond is considered as if he prayed or said those items. The example they cite is if someone is in the middle of his silent amidah and he hears the shat"z saying kedusha. He cannot answer kedusha with them. Therefore, if he stopped his prayers, remained silent, listened and paid attention, it is considered as if he said kedusha, himself.
Comment: So if you are listening to a cd ,and someone is praying and you say Amen.You did pray?
Comment: @Aigle What are you asking me? Who implied anything about a CD? I am talking about "live" praying.
Comment: no Im just asking,Hashem is outside of time.Why would that be a problem?
Comment: @ShamanSTK To me It seems like yes when I read your answer.But still strange.Then It's all about what you have faith in.
Comment: As I understand it, prayer is an active / participatory experience. Your listening to a CD of someone praying is comparable to listening to a recording of Yitzhak Perlman playing Mendelsohn's Violin Concerto. It does not have the same effect as when you hear him live.


Origin of term 'confluency' in cell culture

Question: Since as long as I have been doing cell culture, the word confluency has been used to describe the percentage growth of cells or area covered by them. However, no dictionary that I have found uses this word. I was wondering if anyone could reliably state where the meaning comes from or how the association began, and truly what it means. I don't believe I can post this on another Stack Exchange  because the word doesn't have even a resembling meaning in the dictionary. Cell culture is such an integral part of cell biology, medical research and biological manufacturing. And this term is an integral part of cell culture. I was surprised to be unable to reliably verify its meaning.
Comment: I think that's a fair and sensible guess.
Answer: Besides the etymologic explanation that @aandreev gave, in cell culture this term is commonly used to describe the density of adherent cells and it is used as a measure of their proliferation. It is usually combined with an estimated (or counted) percentage, so 10% confluency means that 10% of the surface the dish or flask used is covered with cells, 100% means that it is entirely covered. The cells grow twodimensional on the surface of the flask in this case. The picture below (from here) illustrates different levels of confluency:

The level of confluency is important as the cells change their growth with changing densities. Low density cells (10-20%) usually grow slower than 50% confluent cells. If the plate is complete grown by cells, they tend to grow much slower again. This influences their genetic program, behaviour in experiments and transfections.
As @Roland pointed out it is important to say that confluency is not a hard measure, but rather an estimate of the cell density. Different people will get different estimations, but the trend should be the same.
Comment: @rhill45 Confluence means coming together. It actually does not mean how dense the culture is but this word has been used for several ages now for what Chris has said in his answer. Perhaps this term came from Dictyostelium (this is a wild wild guess)
Comment: Chris thank you thorough answer, any thoughts on the etymology of the word as used here other than @aandreev above?
Comment: @rhill45 I think aandreev's answer about the etymology is right. I don't know any other.
Comment: This is good answer. I would add though that the % confluence (area covered) is actually pretty hard to estimate by eye, since cultured cells often change size and conformation as they grow more dense. Different people typically give different estimates from the same image (I'm not sure that last one is 90%, for example :)  So confluency numbers are rather unreliable.
Comment: @Roland Thanks, this is a good point. I will add it.
Comment: @rhill45 — for the record, I think that is not an etymology, as I explain in my comment to the answer in which it occurs.
Answer: con- (com-) is prefix that usually means "togetherness", joining. Root fluency/fluent comes from latin fluere, to flow.
Source: Google's definitions for con- and fluency (information scraped from OUP).
Comment: Although this is a reasonably analysis of the meaning of the two components of the word *confluency* it is not a definition from any dictionary as the word does not occur in any dictionary. In my opinion it is invalid as etymology (the origin of a word and the historical development of its meaning) as the word is either a corruption of *confluence* or (more likely perhaps) a recent formation from the adjective *confluent*. Neither of these words are derived from *fluency* in English as explained in note [2] of my own answer.
Answer: The word confluency is a variant of the word confluence, although this variant only appears with any frequency in the context of cell culture [1]. The word confluence itself appeared in the fifteenth century and is derived from the Late Latin confluentia meaning "a flowing together" [2]. In English it was initially used for the flowing together of two or more streams, but acquired a large variety of more figurative meanings [3].
The word confluence (but rarely confluency) occurs in various biological contexts in the first half of the twentieth century [4], but the first example I can find in relation to monolayer cell culture is in 1961 [5], although the term confluent appears in the 1950s [6]. The form confluency seems to have appeared at about the same time as confluence [7]. Since the 1960s both forms have been used by different authors, currently with comparable frequency [8]. Some authors employ either one or the other exclusively, others use confluency when indicating a percentage designation and confluence to indicate the absolute concept — or vice versa [9].
The reason that confluency is not defined in general dictionaries (or even in the Oxford Dictionary of Biology [10]) can only be surmized. None of the online dictionaries I have consulted [11] give the cell culture usage as an example of confluence, suggesting that its use is less frequent than in other technical contexts, where the meaning is similar. With this usage of confluence not being thought to merit separate mention (irrespective of the importance or otherwise of cell culture) then the need to define an alternative form would not have arisen.
It should be added that there is there is a Wikipedia entry for confluency [12] but, despite its title, this uses the term confluence in its definition:

"In cell culture biology, confluence refers to the percentage of
  the surface of a culture dish that is covered by adherent cells. For
  example, 50 percent confluence means roughly half of the surface
  is covered, while 100 percent confluence means the surface is
  completely covered by the cells, and no more room is left for the
  cells to grow as a monolayer."

Notes
[1] The hits reported by a Google Book ngram for the word confluency between 1800 and 1954 were analysed individually, as journal results from ngrams often have erroneous dates. There was one example (1829) of its occurrence before 1900, and 13 before 1950, about half in relation to vaccines or biological phenomena.
[2] The etymology of confluence given in the online etymological dictionary is:
early 15c., "a flowing together, especially of two or more streams," from Late Latin confluentia, from Latin confluentem (nominative confluens), present participle of confluere "to flow together," from assimilated form of com "with, together" (see con-) + fluere "to flow" (see fluent).
I would emphasize that the word confluence is not a compound formed in English by adding a prefix to the word fluency, but derives from the compound word, confluentia, already evolved in Late Latin (i.e. by the sixth century).
[3] The Oxford English Dictionary quotes an early instance of the extension of the meaning of the word confluence (1606) as "In this confluence of so many prosperous successes". A variety of examples, appearing to come from the fields of politics, philosophy and mathematics, can be found in the Cambridge Dictionary online for its second definition of confluence, "a situation in which two things join or come together".
[4] This can be seen by going to the websites of some of the older biological journals (e.g. Journal of the National Cancer Institute or the Journal of Experimental Medicine) and searching for the word confluence.
[5] 1961 Yearbook of the Carnegie Institute of Washington (p.66).
[6] For example W.R.Earle (of Earle's saline) uses it in a paper on the growth of fibroblasts in 1951, and T.T.Puck  (of Puck's saline) uses it in a 1958 article in Experientia. The earlier use of confluent (also of 15th century origin) in relation to monolayer culture suggests that the word confluency, rather being a corruption of confluence, may have been formed from the adjective — perhaps in ignorance that a noun form already existed.
[7] Königsberg et al. (1960) J. Biochem. Biophys. Cytol. 8 333–343.
[8] There seems to have been division at the outset. In the US, Harry Eagle and Renato Dulbecco used the term confluency, whereas Howard Green and George Todaro used confluence. What one might refer to as the Glasgow school always used confluence: John Paul) at the Beatson Institute and his student Ian Freshney, both authors of influential books on cell culture. The more recent frequency of use may be judged from a Google ngram for "cell confluence v. cell confluency".
[9] Searching for confluence in the Journal of Cell Science and examining recent issues brings up results for both confluence and confluency. This recent paper uses confluence exclusively both as an absolute concept and as a percentage, whereas this recent paper, for example, uses confluency exclusively in both absolute and numerical senses. Another paper refers to confluency, but to 70% confluence, but exactly the opposite is found in this paper which refers to confluence, but 70–80% confluency. Some papers — e.g. this alternate at random. The editors of the journal obviously do not care.
[10] The Oxford Dictionary of Biology has nothing between the entries for cone and confocal.
[11] Collins, Chambers, Cambridge, Lexico or Merriam-Webster.
[12] Wikipedia entry for confluency.
Comment: If this seems a little over the top, it was my time that was spent. I don't think it was wasted as demonstrates how one can use search indexes of various sorts to try to trace the history of biology. This overturned my previous view of the term which I had expressed in a previous answer that I decided to delete.

Origin of term ‘confluency’ in cell culture


nintendo 64 emulation, confused with mupen 64pluse/m64py, project 64 freezes

Question: I'm in a huge pickle. I'm trying to help a friend to whom I installed Linux for. He is happy with it since he gave up that old xp. but the problem now that we are both faced with is playing our 64 games on Linux. I installed project 64 through wine and it works at first but at a certian point it the frame rates drop dramaticly. him and I both have integrated 256 mbs intel graphics cards wich n64 should run very smoothly on.
but anyway thinking that some sort of compatibility issue with directx9 in wine or something, I tried to install mupen64plus, and found myself not so happy that it is in command line I attempted to find a front end. I installed m64py, and it opens but it wants all these plugins, to wich I thought I had it all setup, then it wants a library file. I do not know where to look for one. I tried to google one. and save for compiling crap no dice. I do not want to compile a program I AM NOT A PROGRAMER. I am a linux newb and I am tryying to keep it basic. Please help me. please help me friend. Thank you.
Comment: Older versions of mupen64plus had a graphical user interface, try using an old package.
Answer: Thats ok. I figured it out. turns out all I needed to do was install m64py and download mupen64plus in parts. unzipped the tarballs into folders and told m64py what directories they go in. Took a while to figure out but I am glad I did


Connecting to raspberry pi to set up wireless access point

Question: I am using the following link :https://thepi.io/how-to-use-your-raspberry-pi-as-a-wireless-access-point/ to set up my raspberry pi to act like a wireless router. So far I have installed raspbian on a sd card. I don't have access to an external monitor or a keyboard. I have access to a ubuntu laptop. I want to use the commands on the tutorial to set up the pi but how do I connect to pi in the first place. This is the first time I am doing this and I have no idea. I have an ethernet cable and wifi access that is again provided by a raspberry pi that was already set up by somebody else. How can I connect to the raspberry pi in the terminal to execute the commands? Thanks!
Comment: Your question is unclear. The Pi makes a poor router and if I wanted to setup an Access Point I would follow the Foundation tutorial. Your first task should be to configure Raspbian. See [How to set up networking/WiFi](https://raspberrypi.stackexchange.com/a/37921/8697)  You COULD follow "Headless Raspbian WiFi Setup"  but it is better to connect to your router via Ethernet.
Comment: Okay the thing is I have a terminal that says my username. How do I connect to the pi so that I can get pi@raspberrypi or something like that so that I can control the pi from my laptop terminal and use the commands.
Comment: In other words how do I ssh into a headless pi. I have an ethernet cable if it helps.
Comment: `ssh email@example.com` or `ssh pi@`.
Answer: ENABLE SSH
SSH is what you're looking for. If you connect your RPI ethernet port to your router you can use arp -a (linux, mac) to see all IP addresses on your network. You will likely see your pi as  pi (192.168.1.15) or something along those lines.
Once you find the pi IP you can connect to the raspberry pi using the ssh command. When connecting to the raspberry pi a prompt will ask you for a password (it is usually raspberry on raspbian OS).
ssh firstname.lastname@example.com

If this doesn't work, SSH might not be enabled. You can take your SD card and put create an empty file with the name SSH at the boot directory.
Comment: When I execute `apr -a` on my Raspberry Pi I get: `-bash: apr: command not found`. Did you mean `ip a`? But this only shows the IP addresses of the local interfaces not all IP addresses on the network.
Comment: forgive me typo. try `arp -a`
Comment: Ah.. you mean asking the local arp cache. But this will not give you all IP addresses on your network. It will only show addresses that where addressed the last 5 minutes. If you haven't addressed the RasPi the last 5 minutes (e.g. with ping) it isn't shown in the arp cache. Using `nmap` seems to be better.


Why does food spoil in the freezer?

Question: Many recipes suggest storing perishable food, such as left-over chicken stock, in the freezer for up to 2-3 months. Why could one not store it frozen for longer, surely bacteria and mould cannot grow in a deep freezer to spoil the food?
Answer: Most freezers are frost-free, which means that they occasionally cycle above freezing to prevent formation of frost on the walls of the freezer. This makes them easier to maintain but it shortens the storage longevity of the food.
This makes products stored in them vulnerable to freezer burn, which is a loss of moisture. It can also cause ice and IQF products like frozen fruits or vegetables to solidify into a single mass. If you have ice cube trays, you may even notice them becoming empty after a few months of sitting unused.
Freezer burn is a loss of quality, though, not a health issue. The food isn't spoiling.
If you have a "deep freeze" or a non frost-free freezer that you only access occasionally, you can certainly keep foods for nearly indefinite periods of time without worrying as much about freezer burn.
You can also reduce the likelihood of freezer burn by following better freezer practices.
Resources available here and here and here.
Comment: Can I tell this by the freezer not having any frost inside? My fridge always says -18° in the freezer.
Comment: If there's no frost, it's a pretty sure bet that it's frost-free. It's going to be really cold most of the time but it will occasionally pop above freezing to prevent frost formation.
Answer: Actually, it's a matter of physics. More heat = more energy = all actions and reactions happen more quickly.
Freezing slows down but does not stop chemical processes. Those would not stop unless your freezer could chill things to absolute zero. If your food is in the refrigerator, processes take place in a matter of days, because the food is relatively warm. In the freezer, the processes still take place, but they do so much more slowly. Bases and acids still react; they just do it in slow motion, so to speak. Many bacterial agents are killed by freezing, while others just go dormant; a few even still remain active, but at such a slow rate that they are not considered a risk. Because everything happens slowly, freezing offers a long shelf-life, but on the other hand, because processes still occur, the shelf-life is not indefinite. The processes can result in something as minor as freezer burn or as major as actual spoilage (usually chemical rather than bacterial), if given enough time and the right chemical reactions.
When a limit is given for freezer storage, it is usually based on the chemical composition of the substance, its tendency for ingredients to react to other ingredients within it, its tendency for compounds in the substance to react with outside molecules, and the chemical stability of various compounds (i.e. their ability to remain stable in the freezer environment). Most freezer storage limits assume packaging with a single barrier that is air-tight but not vacuum-sealed, and water content percentages that are such that the food is not noticeably damaged by freezing for a certain length of time. This is why vacuum-sealing or multi-layer wrapping can extend freezer storage limits, and why nuts keep longer than veggies in the freezer without damage.
Comment: There are a lot of true things in your answer, but the suggestion that chemical or bacterial spoilage happen in the freezer doesn't seem great. Far and away the primary reason for limited storage lifetime in the freezer is *quality* loss (mostly freezer burn), not chemical reactions or bacterial spoilage. I know you did mention freezer burn, but it's buried among a lot of other things.
Comment: Freezer burn is certainly a chemical (but not microbiological) process?
Answer: I was under the impression materials deteriorate due to oxydation. Bacterial and fungal growth stops, but degradation due to oxydation still happens.  The reason why vacuum sealing is effective is due to the fact that you remove all oxygen from the package. Afterwards, as oxygen can permeate most packaging, it is hard to prevent the oxydation effect from happening.
This next to the technical limitations ofcourse.

Why does food spoil in the freezer?