Sticking it out for longer

Question: I am running to loose weight, I like using the treadmill, I put it on 2% incline and set the speed to 10.0 mph. Now the thing is, I think this is more of a mental barrier than a physical one, I always get off around 300 calories/15 minutes...I noticed that I am doing this, there has been the odd occasion where I go longer but usually for some reason I just get off, it is a mental barrier, it isn't boredom, I just feel more mentally inept than physically because despite breathing really hard I can go for longer... I am 5"9 and weigh 180 lbs.
I have a lot of muscle underneath my fat.
The same goes for when I am interval training, I will do 12mph-14mph for 2 minutes and 5mph for 1 minute for 15 minutes and get off...does anyone have any suggestions for this mental barrier problem I am facing?
Comment: Slow down. You're running 6 minute mile pace. Try running at a 7 minute/mile pace for 30 minutes. For endurance exercise, you shouldn't be "breathing really hard".
Answer: You've acknowledged that it is a mental barrier you are facing. The most effective strategy here is going to be to break through it mentally. You say you "usually for some reason...just get off", well, in all honesty, my advice is simply to not get off. Recognize when you are approaching this point that there will be pressure from your body to stop, then respond to that and continue to push forward.
With endurance exercises, mental fitness is a much larger component of ability than with weightlifting. Training your mind to recognize points of greater and greater fatigue as your breaking point can usually be just as effective, to a point, as increasing your physical fitness. Once you begin to push through this 15 minute point on a regular basis, you'll find it easier to push through, and will move on to a later breaking point for the run.
For how you can help yourself decide to push through, my strongest recommendation is to find a person or group to run with. Competition makes it much easier to reach your physical limits, as its much harder to give up when you see others continuing onward. Another option, as Chris mentioned, is to incorporate other exercises right after 15 minutes, as a way to prove to yourself you have energy left. If one day you run for 15 minutes, then bike for another 10 right after, the next time you run you will be more aware of the remaining energy you have at the end of 15 minutes, and can use that knowledge to push on.
Comment: you are right, I used to be able to skip for an hour, but I let my self go and I never thought to myself that this mental barrier would be more of a problem than the weight, I am just going to have to not get off, and really push, you are right, I do get to that 15 minute point, then I think to myself "not this time" but I just automatically do it, I am going to have too really push it. Thank you for this.
Comment: One of the general willpower tricks when trying to resist temptation (here, the temptation to stop) is to establish a near goal and make a mental promise that you just need to get there and you'll consider it again. In studies (and in my experience) if you set yourself a goal of "just 30 more seconds" when you feel like you can go no further, you'll generally make those 30 seconds and then more.
Comment: @SeanDuggan thank you, over the past two days I have just kept saying one more minute and I am going 8mph for 45 minutes over the past two days burning 450 calories, tonight I plan to go for an hour, thank you so much for this!
Comment: @user2405469 Great to hear! Keep it up
Answer: Another suggestion that has worked for me specifically when running on a treadmill (although I am certainly not running at the speeds you indicate) is to remove the time indicator from your frame of reference. Just block the time indicator so that you are not obsessing over the time (be this lay a towel over the treadmill time, or remove the clock from your line of sight, etc.). If you do not have other distractions, just focus on your movements and your breathing to try and streamline your form. Alternatively, as running on a treadmill can be boring (for me at least), having the tv or radio on may help. If you get absorbed in a show/broadcast you may find that the mental block is easier to overcome as the time you have spent running is no longer the primary focus. Lastly, if you are comfortable running outside, the extra visual inputs and attention from your surroundings can often allow you to push further... plus, unlike the treadmill if you run for 10 minutes out, you will have to return (and why not run all the way back instead of walking :) ).
Answer: I feel meanderingmoose's answer is too vague to be useful.
I believe that you should

Set a long term goal
Set several intermediate goals that are realistic
Record your progress
Revise your goals every say 2-4 weeks

As an example, you might say:
Ultimate goal Lose 20lbs by Summer 2015
Intermediate Goal: I want to be able to run until the counter says 600 calories.
Current capacity: 300 calories.
Intermediate-intermediate goal: Every other sessions I will increase that count by 10 calories.
So say you run twice a week, try and hit 310 calories twice. If you go for 1 month you should be at 340 calories. Write down your progress and how you feel if that helps you.
At the end of the month ask yourself, was that too easy? Too hard? Have you hit a plateau and need to do something else for a while? Are you on track to lose that weight? Then revise your intermediate goals and go for another month, then revise again.
Be specific and realistic with your intermediate goals. If you set yourself something well beyond your ability, you may lose confidence, lose interest, get injured, over train etc.
You need to be able to constantly chip away towards your goal, form good habits, and show yourself that you can in-fact push slightly beyond your perceived limits and still be OK at the end.
Comment: Thank you for this, it is really helpful advice and I will implement it! I found meanderingmoose's very helpful, I slowed down to 8mph and stuck it out for 45 minutes burning 450 calories. I have done that for 2 days now, I plan to go higher tonight. I have been underestimating myself a lot, I am hitting points that require more mental effort than physical. My goal is to add another 15 minutes tonight making it an hour and try increasing the speed a little. I have tried increasing the speed by 0.3 miles and I stuck it out for 45 minutes.
Answer: One suggestion could be to swap to another form of cardio following the treadmill.
I do 30 minutes on a rowing machine at the start of my workout and 30 minutes on the treadmill at the end of the session.
If you were to alternate between two machines, doing your 15-20 minutes on each, would that be enough to stave off the boredom?
Also, I listen to podcasts or music which stops me clock-watching too much. The time passes quickly listening to spoken word podcasts, more slowly with music I find.
Answer: There are three very simple things you need to know for losing weight: EAT LESS--DRINK MORE WATER--EXERCISE MORE
Running is a great way to lose weight but you won't only be losing fat you'll lose water weight at first; then you'll be losing both fat and muscle.
I ran on 5.4 for 25-30min with 1min walking before 1min walking after so I would get off at 27-32 or longer if I could. I would try to do it for 3 days a week. I lost 20lbs in two months and it was great I was happy with where I was.
check out this website for a very good calorie calculator: http://scoobysworkshop.com/calorie-calculator/ it's not dieting and whatever bad stuff people do; it tells you the calories your body uses and how many you need to lose weight. It's not saying you can only eat this and that. It doesn't care if you eat 2000 calories of mcdonalds or 2000 calories of ice cream or 2000 calories of spinach...2000 calories is 2000 calories....its only to help you. Also another great website is http://www.myfitnesspal.com/ it tells you the calories in foods to help you.
It is a great tool, but remember don't give up and don't eat extra...you're not tricking me or your mom or your neighbor, only yourself.
Don't pay for anything that people on the internet sell...don't think about juicing...don't do the no carb diet unless you're already 6 or less % body fat and you want to be less.
The whole thing is just do it, it is hard and it will take time...it took me two months to get rid of the 20lbs but look how long it took me to put it on prolly a year maybe more. It's all well worth the work, be consistant.
Comment: How did your response answer his question? His question is *how to stay longer while exercising* and not *what to do to lose weight.* If you don't modify your response to answer the real question, it's likely going to get downvoted.

Sticking it out for longer


How did the monastic tradition evolve?

Question: In the 4th Century there was a strong monastic tradition, which usually involved living in solitude or small groups in the wilderness. By the 12th Century the monastic life was being lived in large groups, and generally close to large communities. How did one tradition evolve into the other?
Comment: The original monastic tradition had nothing to do with "working for the church". Even today that's not really the point.
Comment: I am guessing that when it started out there were not many interested in working for the church. Over time as the church grew in power and wealth more wished to work for the church so the monastaries grew larger out of need. But I am interested in any actual studies on this.
Comment: Great Question; I'm looking forward to the answers.
Answer: Monasticism was unknown until the end of the third century. Paul expressed that he preferred celibacy, but there was no "command from the Lord" to remain unmarried. (Simon) Peter, according to Catholic tradition the first Pope, was himself married.

Luke 4:38 And he arose out of the synagogue, and entered into Simon's
  house. And Simon's wife's mother was taken with a great fever; and
  they besought him for her.
MATTHEW 8:14 And when Jesus was come into Peter's house, he saw his
  wife's mother laid, and sick of a fever.

Widows were treated with special respect, but encouraged to remarry and bear children if still within child bearing age. More emphasis was placed on missionary and charity work than meditation or spiritual development.
Over time, the custom developed of going into the desert (or otherwise being alone), when faced with an important life decision, a desire to commune with God, etc. These people were called hermits, a term which means "desert dwellers". The most famous of these early hermits was Anthony of Egypt (251-356). Athanasius' Life of St. Anthony began to make the hermit life popular, both because it portrayed it as a path to eternal life, and because Anthony was portrayed as an athlete for Christ, a heroic figure.
Now there were so many hermits that it was starting to get crowded. A hermit named Pachomius (290-346) instituted some rules; that the monks should live in isolated huts, produce their own food and clothing, and should never speak to one another. Because they were no longer dependent on public charity, their growth was unlimited, and monasteries and monks began to spread rapidly.
Comment: That's interesting, but it doesn't really say how the *hermit* tradition evolved into the *monastic community* tradition.
Answer: See Pachomius the Great (Wikipedia)
St. Pachomius the Great is one of the figures instrumental in moving monastic life from the life of hermits (old as dust) and small communities.
As for cenobitism, the widows in the New Testament were parochial nuns. If you consider the function of old widows in almost every church, you will find they generally fulfill the duties that nuns do, though in a local setting. A large church would have a fair number of these celibate (since post-reproductive age), prayerful and godly women. If you consider how Paul treats 'the widows' it is precisely as an order of nuns would be treated by the overseeing abbess or bishop.
The mens' tradition seems to have grown out of the former mens' tradition of hermit life, such as what St. John the Baptist lived. It is with Antony (my own patron) and Pachomius that we see people gathering around a single elder or abbot and forming a community. It is with Pachomius that the communites became sizable; Scetis (Antony's) still exists, but it has never been large. Pachomius' communities did not themselves survive (as many of the pilgrim cities did not) but his tradition and practices which allowed this organization did.
Answer: There are basically three forms of monastcism and they are still extant.
Anachoretism - the first form to emerge was living in complete solitude. Hermits however sometimes accepted disciples that would watch their life and then leave. There are still hermits living e.g. in rocky parts of Mt. Athos that don't see other monks for long periods of time.
Idiorythmia - when monasticism became popular, some areas fit for monastic life started attracting monks and monastic societes as e.g. Nitra emerged. Monks would meet at Liturgy and would counsel some things together, yet every brother would be econimically independent.
Cenobitism - as Bob already said - this form was instituted by St Pachomius. Monks live in a commune. They work together and their material needs are fullfilled by the community. This form is the safest and easiest, because monks can comfort each other and the strict obedience protects them from straying on their spiritual path. This is why it is most popular form today. But the two former are not extinct.
Comment: Interesting overview, but it does not address how the various forms evolved from each other, which the question is asking.
Comment: Idiorythmic life evolved from eremitism when monks started to gather in deserts. Cenobitic life was rather instituted than gradually evolved
Answer:
Orthodox monastery in New Mexico

I think the other answers addressed the question well.  Kallistos Ware's section on "Saints, Monks, and Emperors" in The Orthodox Church fills in some additional details.
[Not that it is particularly relevant to the question, but I have been blessed to know a number of monastics and have stayed myself for a time at an Orthodox monastery in New Mexico.  There is also a Russian Orthodox hermit and a women's convent close to where I live in Texas - I have visited both.  A few years ago I was able to visit a monastery (Alexander Nevsky Lavra) and convent (St. John of Rila) in St. Petersburg, Russia.  I also was educated at a Roman Catholic monastery/high school and an elementary school run by a Roman Catholic convent, so I have personally been exposed to both Eastern and Western monasticism, male and female.]

The monastic life first emerged as a definite institution in Egypt and
  Syria during the fourth century, and from there it spread rapidly
  across Christendom. It is no coincidence that monasticism should have
  developed immediately after Constantine's conversion, at the very time
  when the persecutions ceased and Christianity became fashionable. The
  monks with their austerities were martyrs in an age when martyrdom of
  blood no longer existed; they formed the counterbalance to an
  established Christendom. People in Byzantine society were in danger of
  forgetting that Byzantium was an image and symbol, not the reality;
  they ran the risk of identifying the kingdom of God with an earthly
  kingdom. The monks by their withdrawal from society into the desert
  fulfilled a prophetic and eschatological ministry in the life of the
  Church. They reminded Christians that the kingdom of God is not of
  this world.
Monasticism has taken three chief forms, all of which had appeared in
  Egypt by the year 350, and all of which are still to be found in the
  Orthodox Church today. There are first the hermits, ascetics leading
  the solitary life in huts or caves, and even in tombs, among the
  branches of trees, or on the tops of pillars. The great model of the
  eremitic life is the father of monasticism himself, St Antony of Egypt
  (251 – 356). Secondly there is the community life, where monks dwell
  together under a common rule and in a regularly constituted monastery.
  Here the great pioneer was St Pachomius of Egypt (286 – 346), author
  of a rule later used by St Benedict in the west. Basil the Great,
  whose ascetic writings have exercised a formative influence on eastern
  monasticism, was a strong advocate of the community life, although he
  was probably influenced more by Syria than by the Pachomian houses
  that he visited. Giving a social emphasis to monasticism, he urged
  that religious houses should care for the sick and poor, maintaining
  hospitals and orphanages, and working directly for the benefit of
  society at large. But in general eastern monasticism has been far less
  concerned than western with active work; in Orthodoxy a monk's primary
  task is the life of prayer, and it is through this that he serves
  others. It is not so much what a monk does that matters, as what he
  is. Finally there is a form of the monastic life intermediate between
  the first two, the semi-eremitic life, a 'middle way' where instead of
  a single highly organized community there is a loosely knit group of
  small settlements, each settlement containing perhaps between two and
  six members living together under the guidance of an elder. The great
  centres of the semi-eremitic life in Egypt were Nitria and Scetis,
  which by the end of the fourth century had produced many outstanding
  monks – Ammon the founder of Nitria, Macarius of Egypt and Macarius of
  Alexandria, Evagrius of Pontus, and Arsenius the Great. (This
  semi-eremitic system is found not only in the east but in the far
  west, in Celtic Christianity.) From its very beginnings the monastic
  life was seen, in both east and west, as a vocation for women as well
  as men, and throughout the Byzantine world there were numerous
  communities of nuns.

St. Katherine's monastery in the Sinai Desert

Because of its monasteries, fourth-century Egypt was regarded as a
  second Holy Land, and travellers to Jerusalem felt their pilgrimage to
  be incomplete unless it included the ascetic houses of the Nile. In
  the fifth and sixth centuries leadership in the monastic movement
  shifted to Palestine, with St Euthymius the Great (died 473) and his
  disciple St Sabas (died 532). The monastery founded by St Sabas in the
  Jordan valley can claim an unbroken history to the present day; it was
  to this community that John of Damascus belonged. Almost as old is
  another important house with an unbroken history to the present, the
  monastery of St Catherine at Mount Sinai, founded by the Emperor
  Justinian (reigned 527 – 65). With Palestine and Sinai in Arab hands,
  monastic pre-eminence in the Byzantine Empire passed in the ninth
  century to the monastery of Stoudios in Constantinople. St Theodore,
  who became Abbot here in 799, reactivated the community and revised
  its rule, attracting vast numbers of monks.
The Orthodox Church, pp. 36-37

What follows pertains principally to monasticism in the Orthodox Church:

Since the tenth century the chief centre of Orthodox monasticism has
  been Athos, a rocky peninsula in North Greece jutting out into the
  Aegean and culminating at its tip in a peak 6,670 feet high. Known as
  'the Holy Mountain', Athos contains twenty 'ruling' monasteries and a
  large number of smaller houses, as well as hermits' cells; the whole
  peninsula is given up entirely to monastic settlements, and in the
  days of its greatest expansion it is said to have contained nearly
  forty thousand monks. The Great Lavra, the oldest of the twenty ruling
  monasteries, has by itself produced 26 Patriarchs and more than 144
  bishops: this gives some idea of the importance of Athos in Orthodox
  history.
There are no 'Orders' in Orthodox monasticism. In the west a monk
  belongs to the Carthusian, the Cistercian, or some other Order; in the
  east he is simply a member of the one great fellowship which includes
  all monks and nuns, although of course he is attached to a particular
  monastic house. Western writers sometimes refer to Orthodox monks as
  'Basilian monks' or 'monks of the Basilian Order', but this is not
  correct. St Basil is an important figure in Orthodox monasticism, but
  he founded no Order, and although two of his works are known as the
  Longer Rules and the Shorter Rules, these are in no sense comparable
  to the Rule of St Benedict.
A characteristic figure in Orthodox monasticism is the 'elder' or 'old
  man' (Greek gerōn; Russian starets, plural startsy). The elder is a
  monk of spiritual discernment and wisdom, whom others – either monks
  or people in the world – adopt as their guide and spiritual director.
  He is sometimes a priest, but often a lay monk; he receives no special
  ordination or appointment to the work of eldership, but is guided to
  it by the direct inspiration of the Spirit. A woman as well as a man
  may be called to this ministry, for Orthodoxy has its 'spiritual
  mothers' as well as its 'spiritual fathers'. The elder sees in a
  concrete and practical way what the will of God is in relation to each
  person who comes to consult him: this is the elder's special gift or
  charisma. The earliest and most celebrated of the monastic startsy was
  St Antony himself. The first part of his life, from eighteen to
  fifty-five, he spent in withdrawal and solitude; then, though still
  living in the desert, he abandoned this life of strict enclosure, and
  began to receive visitors. A group of disciples gathered round him,
  and besides these disciples there was a far larger circle of people
  who came, often from a long distance, to ask his advice; so great was
  the stream of visitors that, as Antony's biographer Athanasius put it,
  he became a physician to all Egypt. Antony has had many successors,
  and in most of them the same outward pattern of events is found – a
  withdrawal in order to return. A monk must first withdraw, and in
  silence must learn the truth about himself and God. Then, after this
  long and rigorous preparation in solitude, having gained the gifts of
  discernment which are required of an elder, he can open the door of
  his cell and admit the world from which formerly he fled.
The Orthodox Church, pp. 39-40

A really excellent movie to watch to get a feel for Russian monasticism is The Island (Ostrov).  It used to be available on Netflix, but I think today it is only available on DVD.  As an aside, the actor who plays the main character - a monk - was previously a famous rock star in Russia.  After he finished the movie, he took his family and went to live in seclusion in Siberia or somewhere remote.

Another good book involving the monastic life is Everyday Saints, written by a Russian monk.  Before being translated into English, it was the number one bestselling book in Russia.  Several million copies have been sold (It's really hard to put down).

Based on my personal experience and knowledge, I would say that Orthodox monasticism has not changed much from what it has been since the 17th century or so.  One exception was the form it took in Russia after the Bolshevik Revolution.  It is estimated that over 200,000 monks and nuns were executed or died in Gulags, so many monastics went underground or became "secret monks" or "secret nuns".  There are true stories of such people in the book, Father Arseny: Priest, Prisoner, Spiritual Father.

How did the monastic tradition evolve?


Youtube embed is blocked by corporate network, how to detect and offer an alternate self hosted version?

Question: I have a youtube video embedded in a popup window, which works fine, but for some users within my network Youtube is blocked. What is the simplest method to offer them an alternate self hosted version on our server via a link.
Answer: This answer on StackOverflow to "Detecting if YouTube is blocked by company ISP" provides a JavaScript solution for detection of a blocked YouTube situation.
Answer: I can't see a good solution for doing this programatically. Perhaps you should offer the user a button allowing them to self select?
Comment: Looks like my only option without getting too complicated, thanks.
Answer: Alternatively, you could use the onload event handler on the YouTube embed iframe to check if it gets loaded or not. However, one drawback to this approach is that a firewall could replace the page instead of blocking the connection.
It's probably better to use the GData YouTube JSONP services to test if they're accessible and returning valid data. This would be a failsafe method perhaps slightly more accurate than Mike's suggestion—though that in itself should be pretty safe.


How to choose suitable pyramid levels and tile size?

Question: I have a big tiff file and i want to create tiles with gdal_retile. However  I am still concerned about the pyramids levels and the tiles' size. how can I choose suitable pyramids levels (for example 5, 6 or 18 zoom level) and the pixel size for each of my tiles?
Answer: I don't think you can make a sensible tradeoff without more information.
I would suggest looking at the "Well Known Scale Sets" that are defined in the OGC WMTS specification. That will give you something that is easy to work with when you're mixing in other (raster) data.


50K, what to do with it?

Question: I'm 26 and a double masters student in transportation planning and engineering. I have received 50k in settlement money; I don't know what's the best course of action with this money. Im looking at 56,000 in student loans at 6% APR over 10 years. I graduate in two years, then, upon finding a job, I expect a minimum starting salary of 50k. I earn a small stipend from an internship, about 800 a month. I pay 550 in rent. Should I invest or should I try to reduce the loan? Should I save it all and worry about it when I graduate? Should I buy a condo and rent it to other students?
Comment: If you think you can invest it and get more than 6%, invest it. Otherwise pay off the student loan. Be sure to save some as a buffer.
Comment: Are your loans subsidized?
Comment: Does this answer your question? [What to do with sudden wealth?](https://money.stackexchange.com/questions/15784/what-to-do-with-sudden-wealth)
Comment: @Tvde1: If you think you can invest it and get more than 6%, especially sufficiently more for the risk to have value, you're a fool.
Comment: Are you currently making loan payments, or do your loan payments start after you finish school?
Comment: Have you received 50,000 U.S. dollars, 50,000 pounds, 50,000 yen, 50,000 Australian dollars, 50,000 rupees... ?  Asking because the value of each of those is rather different, which would affect what you could do with the money.
Comment: @Sean - I don't see that it really matters, OP has given the amount they received, loan amount, expected salary, current income, and a good metric of current expenses. It could be in any of the denominations you listed and not matter.
Comment: Is your student loan accumulating interest while you are in graduate school, or do you have a waiver until you leave graduate school?  If no interest is accumulating, then you might put the money into a high-yield savings account for now and plan to use it later to payoff the loan.
Comment: Before putting all of your money toward the loan or in some sort of financial instrument, maybe read [Is there a good rule of thumb for how much I should set aside as emergency cash](https://money.stackexchange.com/questions/83/is-there-a-good-rule-of-thumb-for-how-much-i-should-have-set-aside-as-emergency)?
Answer: Reduce your loan.
Currently, stocks are especially in United States rather highly valued. If you subtract taxes, you probably won't exceed 6% per year over 10 years. By reducing the loan, you are having an investment that guarantees 6% return.
See your situation like this: you have an investment with 6% guaranteed return. Most people don't. Now invest in the guaranteed return!
Comment: @juhist In the US, many student loans are _subsidized_, meaning that the federal government pays the interest. From the borrowers' point of view, no interest is being charged to _them_.
Comment: Student loans typically don't accrue interest while the student is still in school so they may as well hold on to it and make it at least grow in the pathetically slow way money grows when you don't want to lose it. At least until they have to start paying down the loan.
Comment: I would be careful saying that [stocks are highly valued](https://money.stackexchange.com/questions/117551/dont-invest-now-because-the-market-is-high).  Maybe change or remove that first sentence, as it implies trying to time the market is good advice.
Comment: @Daniel My student loan certainly added the interest to the loan while I was at school. Besides, why would a bank give a student loan for free without interest? They could calculate that later the student pays lots of interest, but then again there would be an incentive to change the loan to another bank who didn't give loans for free and thus charges less interest after graduation...
Comment: @DStanley Oh. That indeed means they money should be invested for a short term (into bonds) and then after graduation used to reduce the loan. Where I live (Eurozone), bond yields are negative but bank accounts do not charge negative interest so if student loans were interest-free where I live, I would save the money to a bank account.
Comment: But it's true that stocks are highly valued: https://www.multpl.com/shiller-pe -- stocks are a wonderful investment, even today, but we all need to understand that while long-term yields used to be 8% before taxes, today they are more like 7% before taxes. If stock valuation was low, they could yield perhaps even 9% in the long term, meaning stock investment return could after taxes exceed 6%.
Comment: Most students who borrow in the U.S. have both subsidized and unsubsidized loans. The unsubsidized loans do collect interest as soon as they are dispersed so it may be worthwhile to pay those off ASAP but the subsidized loans won't gain interest till 6 months after leaving school.
Answer: Don't buy a condo, that would be kind of a horrible idea, even if you can qualify.
If it was me, I would stick it in a boring savings account, something like Ally.  Once you graduate, get settled in potentially a new location, I would use the money to pay off your student loan.  Until then, the money becomes an insurance policy to make sure you have enough money to graduate.
Your best investment, right now, is yourself.  What can you do to raise your future income?
Comment: He's already a double major with an internship. What more is he going to do to raise his income??
Comment: @corsiKa I got the impression that the last paragraph was referring to the last sentence of the previous paragraph: "... the money becomes an insurance policy to make sure you ... graduate".  Implying that ensuring he graduates is what he can do to raise his future income.
Comment: There are accounts that pay higher than Ally. Spend some time looking for them if you go in this direction.
Comment: I really like this answer, 6% interest on the student loans over a few years isn't a huge game change in the long run, since OP can graduate, theoretically land a high(er) paying job, & then pay the loans off w the existing money, it wouldn't all be loss either as Ally interest will pay a bit back over that time too.  A CD that lets you do a few withdrawals might be something to look at, but right now the rate difference between Ally Savings and a CD in that amount is probably less than half a point.
Comment: @Mehrdad what are some of these accounts? Ally is 1.7% which is already pretty good. The only higher one I've seen is Simple at 2.1% but that requires a ton of micromanagement, and Wealthfront at 1.83%, but it's not a savings account you can easily pay bills out of.
Comment: @hmmm: Just one example: ETFCU gives 3.3% on up to $20k. I don't want to list them all but you can find other ones if you just spend a few minutes Googling. ;)
Answer: juhist has a good answer, but it's only part of a full answer.
Saving
You should save a couple thousand so you don't rack up credit card or other debt due to everyday living expenses plus unexpected bills. You don't want to go broke because of car repair, health care bills, or something else you might not be able to predict or prevent. What you make after college is future money. You don't have it now so don't count on it now. Banking on future money is how most people stay broke for their whole lives.
Income
Also, no matter how good you are in school, you won't get $50k right out of graduation. You don't have the experience dozens of other applicants applying for the same jobs have. If you get lucky, or you already have an agreements in place, you might be able to turn your internship into a job, but without that prior agreement in hand, that's not guaranteed either. When I was in high school, I was told that going into a career in computers was a guarantee to get a minimum of $45k a year job right out of college. That was just over 20 years ago. Because of a wide variety of things, such as the stock market and a flood of other people doing the same thing, I didn't make half that for years after going to college. In fact, because of various reasons that I'm not going to share, I didn't get to $45k until about 3-4 years ago.
You might have to get a lower paying job for a year or more before you get your first "real" job in your industry. Finding a job takes a lot of time and effort. Unless you are absolutely at the top of your field and are well known for your work, you aren't likely to see anyone waiting to give you a job when you graduate. It's a hard pill to swallow, but it's unfortunately the truth for the vast majority of us.
Education
You getting a double masters might help, but it might not. My mom and one of my sisters both have masters degrees and it didn't help them. I have another sister that has multiple masters and bachelors degrees and she's decently well off. Just having a masters doesn't guarantee anything. What you do with it and are willing to do to make it matter matters much more.
My one sister that's using her advanced education got it while in the military, so they paid for most of it and she also has massive experience in those fields. She can literally get any job in her field because of her experience and her education.
One of my brothers-in-law has an advanced degree that his job paid for. I don't remember what it is, but he spent years getting it while working full-time. A couple years ago, he got "reduced" from his upper management job when the company was bought, and hasn't found a replacement job since, due to how specialized his position was. He's now doing a travelling maintenance job that probably pays less than half what he used to get. It's a lot less stress and he likes it, but it's not what he was told would happen when he was getting his degree.
Getting to the real answer
The general recommendation is to have 3-12 months worth of living expenses saved in case of emergencies. What number of months you pick depends on how stable you think your income is. Getting $800 a month and then paying $550 in rent leaves only $250 a month, which isn't very much. In fact, that's less than most people pay in groceries a month for a single person, not to mention eating out any, paying utilities, car insurance, gas, and a dozen other bills that are easy enough to incur. Even if you take public transportation, those fares can add up.
If you already have credit card debt or a car loan, pay them off first with what you decide not to save. If you have any other debt, pay that next.
Student loans
Student loans have a variety of ways to defer payments. Not to mention that in the US, they are specifically not allowed to be predatory lenders by law, unlike other debt collectors. Also, student loans are considered differently on your credit history than most of the rest of your debt. You should still want to clear out student loans as fast as possible, but not to the detriment of your health or even other debts. And having a long term loan on your credit history that you are on good terms with (paying regularly or otherwise not defaulting on) is actually beneficial to your credit report. Yes, it means that your debt to credit ratio is affected, but it shows that you are a good debt risk since you are actually paying your loans. Also, deferring your student loans doesn't show up on your credit report, except that you are still in good standing with your student loan creditor.
I've gone through hell with my student loans to where I've been 180+ days late. I finally talked to the creditor and got one of the many deferments they offer and my credit report suddenly said I was in good standing the very next month. The credit reporting agencies don't care about that type of detail in a report, they go off what the creditor says about the loan, and if the creditor is happy with the state of the loan, so is the credit report.
People talk about student loans being a noose around their neck. Sometimes this is true, but it also ignores all of the other debt they have, which oftentimes happens to be a boulder holding them to the bottom of their river of debt. Because student loans are so forgiving and flexible, you should pay them off last*. Once you start getting bills for them, keep paying them on time and the full amount, but always consider that the other loans you'll have to take out are always going to be worse to deal with if you default on them than student loans. Default on a vehicle loan and they repossess it. Default on your house or apartment, and they kick you out.
*The only thing that should be fully paid off after your student loans is a house/condo. Make sure that your future monthly mortgage payment is paid in full before paying the monthly student loans, though. Also, paying more on your mortgage than the minimums will save you thousands by the time you pay it off. Because of the difference in size of loans, the savings of paying more on your house vs paying more on your student loans weights in favor of paying more to the mortgage.
More budgeting information
If you want more information about budgeting and how to deal with money, you can't go wrong with the book "America's Cheapest Family Gets You Right on the Money". I'm not affiliated with this book or family in any way, I'm just another satisfied customer. They go into a lot of detail about how to budget your money as well as how to deal with loans and creditors.
Answer: We don't have enough info for this specific situation, but here's a checklist to follow:

Emergency fund

Depending on the difficulty of finding a job, save 3-6 months of living expenses.

High-interest debt

Credit cards, personal loans, anything over 10% APR needs to be reconciled immediately.

Tax-advantaged accounts

After high-interest debt, you should start looking into tax-advantaged accounts. A 401k is typically better if you plan to retire with little extra income, and a Roth is typically better if you want to retire with a large amount every month (You will be limited by how much you make, be sure to check with a registered financial advisor, as this information can't be taken as investment advice.)

(optional) Other investments

This one highly depends on what you know, but if you think you can do real estate, then go for it. Typically, condos are bad investments, so be sure to do plenty of research if you decide to go that route.

Pay off student loans

You can defer student loans in a ton of different ways, so this is a really low priority to hit. That being said, if you don't have anything else that can make you more money, then paying off your student loan early is guaranteed money.

50K, what to do with it?


Transitivity check vs. Transitive Closure

Question: Is checking transitivity of a digraph not easier than (in terms of asymptotic complexity) taking the transitive closure of the digraph? Do we know any lower bound better than $\Omega(n^2)$ to determine if a digraph is transitive or not?
Comment: Not sure what you mean by $n$, but a lower bound of $\Omega(|V|^2)$ is simple - consider $K_n \setminus \{e\}$ for some edge $e$.

Any algorithm will ask have to check if $(u,v)\in E$ for all $u,v\in V$, as otherwise the edge he didn't ask about could be the one missing.

$O(|V|\cdot |E|)$ is an upper bound, as this is the time it takes to compute a transitive closure.
Comment: Consider a directed graph with $n = 3k$ vertices: source vertices $s_1,\dots,s_k$, intermediate vertices $t_1,\dots,t_k$ that are immediate successors of each $s_i$, and sink vertices $u_1,\dots,u_k$ that are immediate successors of each $t_i$.  The digraph is transitive iff each of the arcs $(s_i,u_j)$ is present in the graph.  This requires checking $k^2 = (n/3)^2 = \Omega(n^2)$ edges.  On the other hand, finding transitive closure can be done in $O(n^\omega)$ time, where $\omega < 2.373$ is the exponent of matrix multiplication.  These are the best known bounds.
Comment: Storing the entire transitive closure will cost you extra space.

For some graphs you should be able to hook and shortcut the transitivity check without revisiting edges. See:

An $O(log  n)$ parallel connectivity algorithm,
Y Shiloach, U Vishkin - Journal of Algorithms, 1982
Comment: Here, Siek has implementation notes for the Boost Graph Library http://www.boost.org/doc/libs/1_54_0/libs/graph/doc/transitive_closure.html
Comment: Does your DAG possibly have any additional structure, or do you want fully general results?
Comment: For this question, we assume $|E|=\Theta(|V|^2)$. However the sparse case, $|E|=\Theta(|V|)$, is also interesting.
Answer: Below I'll show the following: if you have an O($n^{3-\varepsilon}$) time algorithm for checking if a graph is transitive for any $\varepsilon>0$, then you have an O($n^{3-\varepsilon}$) time algorithm for detecting a triangle in an $n$ node graph, and hence (by a paper from FOCS'10) you'd have an O($n^{3-\varepsilon/3}$) time algorithm for multiplying two boolean $n\times n$ matrices, and hence by a result of Fischer and Meyer from the 70s, this also implies an O($n^{3-\varepsilon/3}$) time algorithm for transitive closure.
Suppose that you want to detect a triangle in an $n$ node $G$. We can now create the following graph $H$. $H$ is tripartite with partitions $I,J,K$ on $n$ nodes each. Here each node $x$ of $G$ has copies $x_I,x_J,x_K$ in the parts $I,J,K$. For each edge $(u,v)$ of $G$ add directed edges $(u_I,v_J)$ and $(u_J,v_K)$. For each nonedge $(u,v)$ of $G$ add the directed edge $(u_I,v_K)$.
First, if $G$ contains a triangle $u,v,w$, then $H$ is not transitive. This is since the edges $(u_I,v_J),(v_J,w_K)$ are in $H$ but $(u_I,w_K)$ is not. Second, if $H$ is not transitive, then there must exist some directed path from some node $s$ to some node $t$ in $H$ such that $(s,t)$ is not a directed edge in $H$. However, the longest paths in $H$ have $2$ edges, and so any such path must be of the form $(u_I,v_J),(v_J,w_K)$ and $(u_I,w_K)$ is not in $H$, hence $u,v,w$ form a triangle in $G$.
Comment: The Ballard et al paper that you cite talks about Strassen's algorithm in particular. From what I know, none of the matrix multiplication algorithms that use border rank are practical. In particular, I am not aware of practical algorithms for any bound on $\omega$ lower than $2.78$.
Comment: Finding transitive closure is essentially the same as matrix multiplication.  The question is whether the exponent in the lower bound can be raised from 2, or the exponent in the upper bound can be lowered from 2.373.  The chain of reasoning you demonstrate shows that even an optimal $O(n^2)$ algorithm for checking transitivity would only yield an $O(n^{2.667})$ time algorithm for transitive closure -- but we already have an $O(n^{2.373})$ time algorithm.
Comment: The point is that black box reductions exist. The O($n^{2.373}$) time algorithm is far from practical. A practical transitivity checking algorithm that runs in subcubic time however, by the above reductions also implies a practical one for BMM and hence transitive closure. Also, even if you don't care about practical algorithms, it is quite possible that the loss in the exponent from the FOCS'10 paper is not necessary, and triangle detection is probably equivalent to BMM.
Comment: Oh and of course, we could just base the hardness of the transitivity problem just on the presumed hardness of triangle detection. Note that there are no known lower bounds better than $n^2$ for triangle detection, and the best upper bound is $O(n^\omega)$.
Comment: We already have a subcubic practical algorithm, by using any fast matrix multiplication method: see for instance http://cacm.acm.org/magazines/2014/2/171673-communication-costs-of-strassens-matrix-multiplication/abstract
Answer: It looks like that $\Omega(n^2)$ is the best known lower bound, since any lower bound implies a lower bound for boolean matrix multiplication. We know that transitivity check can be achieved using one boolean matrix multiplication, that is, $G$ is transitive if and only if $G = G^2$.
Answer: Figuring if a DAG is transitive is as hard as deciding if a general digraph is transitive (which bring us back to your previous question :) ).
Assume you have an algorithm running in time $O(f(n))$ for deciding if a DAG is transitive.
Given a directed graph $G$, you can use the following randomized algorithm to decide if $G$ is transitive in time $O(f(n)\cdot \log(\frac{1}{\delta}))$ and error probability $\leq \delta$:
<code> 1. for $O(\log{\frac{1}{\delta}})$ iterations:

   1.1. Compute a random permutation on $V$. Denote the result by $<v_1,v_2,...,v_n>$.

   1.2. Set $G'=(V,E\cup \{(v_i,v_j)|i<j\})$ (i.e. compute a random acyclic orientation).

   1.3. If $G'$ (which is acyclic) is not transitive return false.

 2. return true.
</code>
Now it is obvious that if $G$ was transitive, this algorithm return true.
Now assume $G$ wasn't transitive. Let $e_1=(v_i,v_j),e_2=(v_j,v_k)\in E$ such that $(v_i,v_k)\notin E$ (there has to be such edges as $G$ is not transitive).
The probability that $e_1,e_2\in G'$ is $\frac{1}{6}$, therefore in each iteration the probability that the algorithm will figure $G$ wasn't transitive is $\frac{1}{6}$ and after $O(\log{(\delta)})$ iterations the failure probability is at most $\delta$.
Comment: Thanks for the answer. Assume I have an algorithm for deciding if a DAG is transitive in $O(f(n))$ such $f(n)=\Omega(n^2)$. Then, I can decide if a directed graph G is transitive in $O(f(n))$-time as; 1) Obtain strongly connected digraph in $O(n^2)$-time. 2) Check if each component is complete in $O(n^2)$-time. 3) Check if each pair of components, for which there is an edge in the component digraph, is bi-complete, that is there is an edge from every vertex of one component to every vertex of the second component in $O(n^2)$-time. 4) Check if the component digraph transitive in $O(f(n))$-time.
Answer: I think this should be feasible in linear time, i.e. $O(n+m)$ where $n$ is the number of vertices and $m$ the number of edges. Maybe by adapting some graph traversal scheme to the directed setting? A starting point could be the LexBFS / LexDFS described here; for directed graphs it seems that we should use topological sorting rather than DFS, so maybe it's possible with some LexTSA algorithm to discover?
Comment: This is unlikely IMO, as it would give a probabilistic linear time algorithm for transitivity checking in general digraphs, see my answer.
Answer: Regarding the previous answer, here's a simple way of defining such an algorithm. Assign to each vertex $x$ an index $i(x)$, initialized to $0$. For each $x$, let $M(x)$ denote the multiset of indices of its in-neighbors. We simulate a topological sorting by maintaining a set $R$ of unexplored vertices, initialized to the entire set. At each step, we do the following:

Chose a vertex $x \in R$ whose multiset $M(x)$ is minimal (in the multiset order);
Update $i(x)$ to the current loop counter and remove $x$ from $R$.

Can this algorithm be used for your problem, or for some other application?
Comment: This would be more appropriate as a comment.


How can I calculate the force on the nose gear at landing?

Question: How can I calculate the force applied on nose gear during landing as nose gear touches the runway little after the landing gear?
I understand force calculations in this question but I think it applies on main gear. How is the force on the nose gear calculated?
Comment: It depends on the angular speed of (de)rotation, i.e. how much quickly the fuselage rotates from landing attitude to horizontal...
Comment: I think you want to start with energy then find the force.
Comment: F = ma, the hard part is figuring out how much mass is on the nose wheel. Ideally at touchdown its not more than a minor percentage of the total aircraft weight, as the goal when landing (small aircraft at least) is to keep the nose wheel up until it comes down gently on its own.
Comment: I calculated the mass on the nose wheel but i am not been able to calculate the acceleration when nose wheel touches down the runway
Answer: Calculating the loads on the nose and main landing gear isn't really different. The answer you linked is a highly simplified approach you should be able to use for the nose landing gear too, but I will provide a "less simplified" approach to calculate the vertical forces. The braking force is already greatly described there.
A simplified approach
First you need to know the impact speed and the spring and damping characteristic of your landing gear.
At touch down there are three possible cases:

Main landing gear touches the ground first. Then the airplane rotates down with an angular speed $\omega_L$. The impact speed of you nose landing gear is therefore $$V_{Impact} = \omega_L \cdot d $$ $d$: distance between the
main and the nose landing gear.
Nose landing gear touches the ground first. (For now empty, if I get time I'll write about it later)
Both landing gears touch the ground at the same time. For a glide angle $\gamma$ the impact speed will be: $$V_{Impact} = V\cdot \sin(\gamma)$$ $V$: airplane speed

The stiffness ($k$) and damping characteristic ($c$) of the landing gear depend mainly on the suspension and the tires used. Tires inflated with a wrong pressure can be really dangerous as they can increase the load on the landing gear.
Putting this data together into a mass spring damper model like in the image

gives you an equation for the nose landing gear movement: $$m\cdot \ddot{x}+c\cdot \dot{x}+k\cdot x = -m\cdot g$$
For the reduced mass $m$ in the model use the mass carried by the nose landing gear.
$$m = LM \cdot \frac{d-d_{CG}}{d}$$
$d_{CG}$: distance from the nose landing gear to the center of gravity
$LM$: aircraft landing mass
$g$: gravity constant
The initial condition for the differential equation is: $$\dot{x}(t=0) = -V_{Impact}$$
The impact occurs at $t=0$.
To calculate the force on the nose landing gear you just have tofind the maximum acceleration and add the static and dynamic loads: $$F_{max}=-m\cdot g -m\cdot \ddot{x}_{max}$$
Real world problems
While the calculations above works for really stiff wings, in reality the loads on the landing gear will be (probably) higher. This is due to the inertial forces of the oscillating aircraft structure.
If you don't understand where this forces come from try moving your arms up and down while standing: you will feel small forces on your feet. Now repeat the experiment with two 60t heavy wings as in the A380 and you'll see that the forces are not neglectable. And were do the oscillations come from? The same as with a guitar string: after a small excitation (plucking the strings/ landing impact) the structure (guitar string/ aircraft wings) begins to oscillate.
What other things doesn't this model take into account? Coupling between nose and main landing gear, rotation inertia, nonlinear tire characteristics,...
Answer: In order to calculate the force, you should start with an estimation of the angular momentum as the nose sinks and the wheel contacts the ground. That angular momentum am becomes zero as soon as the oleo leg is compressed to its maximum stroke, but that takes a measurable time, from first contact of the front wheel with the ground till the extreme compression of the oleo leg.
If you assume that the force f on the oleo leg is constant along the compression stroke, and know the time t it takes, then:
f = am/t
Of course, it's only a rough estimate, but better than nothing...
In order to calculate am, you'll need to know the mass of the plane, its moment of inertia when turning on the main wheels, and the angular velocity of that movement.


How much does a light heat the air around it?

Question: My dad told me to turn off the lights when I'm not using them because it will keep the house cooler. I don't think he is correct that a light can heat up the room. How much of a difference in the temperature would it make? Assume a 60 Watt light bulb running for one hour in a room with approx. 3000ft^3/85m^3 of air. Also assume the air is dry and in constant thermal equilibrium at 1 atm. I think the specific heat capacity of air is about 1 J/g*K, but I am not confident.
Comment: Looks like you have all figures you need. Why wouldn't you plug them into the formula and do the math?
Answer: During a period of $\Delta t = 1\ \mathrm h =3600\ \mathrm s$, the light bulb converts electric power of $P = 60\ \mathrm W$ to light and heat. Assuming that none of this energy escapes from the room, the entire power is eventually converted to heat:
$$\begin{align}
Q &= P \cdot \Delta t \\
&= 60\ \mathrm W \times 3600\ \mathrm s \\
&= 216\ \mathrm{kJ}
\end{align}$$
According to REFPROP (NIST Standard Reference Database 23, Version 9.0), the relevant parameter values of air at the assumed initial temperature of $T_0 = 20\ \mathrm{^\circ C}$ and pressure $p = 1\ \mathrm{atm} = 101\,325\ \mathrm{Pa}$ are a density of $\rho_0 = 1.2046\ \mathrm{kg/m^3}$ and a specific heat capacity at constant pressure of $c_{p,0} = 1.0061\ \mathrm{kJ/(kg\ K)}$.
The initial volume is given as $V_0 = 85\ \mathrm{m^3}$. The corresponding mass is
$$\begin{align}
m &= V_0 \cdot \rho_0 \\
&= 85\ \mathrm{m^3} \times 1.2046\ \mathrm{kg/m^3} \\
&= 102.391\ \mathrm{kg}
\end{align}$$
Ignoring the heat capacity of the walls and inventory, the temperature of the air is approximately increased by
$$\begin{align}
\Delta T &= \frac QC \\
&= \frac Q{m \cdot c_{p,0}} \\
&= \frac{216\ \mathrm{kJ}}{102.391\ \mathrm{kg} \times 1.0061\ \mathrm{kJ/(kg\ K)}} \\
&= 2.1\ \mathrm{K}
\end{align}$$
By way of comparison, a better result may be obtained using the enthalpy of air, since the heat capacity of air is not constant. In this case, however, the difference is insignificant because the temperature change is small. The initial specific enthalpy of air is $h_0 = 419.40\ \mathrm{kJ/kg}$. Thus, the enthalpy is
$$\begin{align}
H_0 &= m \cdot h_0 \\
&= 102.391\ \mathrm{kg} \times 419.40\ \mathrm{kJ/kg} \\
&= 42\,943\ \mathrm{kJ}
\end{align}$$
At constant pressure, the change in enthalpy corresponds to the heat transferred to the air:
$$\begin{align}
H_1 &= H_0 + \Delta H \\
&= H_0 + Q \\
&= 42\,943\ \mathrm{kJ} + 216\ \mathrm{kJ} \\
&= 43\,159\ \mathrm{kJ}
\end{align}$$
Thus, the final specific enthalpy is
$$\begin{align}
h_1 &= \frac{H_1}{m} \\
&= \frac{43\,159\ \mathrm{kJ}}{102.391\ \mathrm{kg}} \\
&= 421.51\ \mathrm{kJ/kg}
\end{align}$$
At a pressure of $p = 1\ \mathrm{atm} = 101\,325\ \mathrm{Pa}$, this specific enthalpy corresponds to a temperature of $T = 22.1\ \mathrm{^\circ C}$.
Note that, at the final temperature of $T = 22.1\ \mathrm{^\circ C}$ and the pressure of $p = 1\ \mathrm{atm} = 101\,325\ \mathrm{Pa}$, the new density of air amounts to $\rho_1 = 1.1960\ \mathrm{kg/m^3}$. Thus, the new volume is
$$\begin{align}
V_1 &= \frac{m}{\rho_1} \\
&= \frac{102.391\ \mathrm{kg}}{1.1960\ \mathrm{kg/m^3}} \\
&= 85.6\ \mathrm{m^3}
\end{align}$$
Therefore, a small amount of air must escape from the room.
Finally, if the heat from a $60\ \mathrm W$ light bulb really is a problem, you might want to leave the room since the human body generates about $100\ \mathrm W$.
Answer: There is no real answer to this because light bulbs do not have a exact temperature do to the various shapes sizes. Also some are Built with different chemicals or metals. But let's say it is a basic light bulb if you touch it warms Ur hand to burning. There is also light radiation as a factor warming the surfaces it connects with so yes a light bulb warms the standard room. To prove this just take a wind mill and hold it over a lamp the windmill will spin slowly form the rise of hot air.
Answer: A 60 watt equivalent LED bulb uses about 9 watts of power, so we can conclude that an incandescent bulb produces at least 51 watts of heat energy for every 9 watts of light energy.
Comment: Actually, a 60-watt lamp produces about 60 watts of heat energy, not counting any light that escapes through windows or converted to glucose by house plants. All the light produced, as well as IR, will bounce around the room until it is absorbed and turned to heat. LED and CFL lamps produce just about as much heat as the electricity consumed.
Comment: You are right, DrMoishe.


How can I make Vim position the cursor at the start of a tab character instead of the end?

Question: Open an empty buffer and insert a tab character then exit to normal mode. When you place the cursor (normal mode) on the tab it will be at the right side of the whitespace. I'm looking for a way so the cursor will be at the left side of the whitespace instead. Thanks!
Comment: This has driven me nuts for years!
Answer: It's only a clumsy workaround, but if you :set list the cursor will be positioned on the other "side" of the tab.
Comment: Thank you! You helped me look in the right place. `:set list listchars=tab:\ \ ` results in what I asked for. Now I just need to see if it's as useful as I thought!
Answer: The cursor in normal mode is on the character not to either side. So you can do i and a to go to insert mode to the left or right of the tab respectively.
Comment: Sorry, I should've been more clear. This has nothing to do with insert mode. I use hard tabs and each hard tab takes up four spaces. When I move the cursor (normal mode) onto a hard tab character it ends up on the right-most column of the tab. I want it to be at the left-most column of the tab. This is purely a aesthetic issue.
Answer: Just use command :set listchars=tab:\ \  list.
I intentionally put list in the end to preserve the space after last backslash in the listchars option value.


Why does weak equivalence principle say gravity is equivalent to acceleration?

Question: I am told that the weak equivalent principle, that $m_i=m_g$ (inertial and gravitational masses are equivalent) is equivalent to the statement that in a small system you can't tell whether you are in a uniform gravitational field, or in an equivalent accelerating frame. My question is about light: Special relativity doesn't say anything about how light falls in a gravitational field, so if you are in a rocket ship accelerating at $g$ why should it be true that when you shine a light in the rocket ship, you see the same thing happening as if you shined a light on earth? (to clarify, if you shot a bullet in the rocket ship, I understand why the trajectory of the bullet would look the same as if the bullet were shot on Earth, but this is because special relativity (or classical mechanics) tells us what the trajectory of a bullet looks like on Earth).
Comment: special relativity and general relativity both make predictions for the motion of light--it travels along null geodesics.
Comment: Re "why should it be true that when you shine a light in the rocket ship, you see the same thing happening as if you shined a light on earth?" ... some things *aren't* the same - the speed of light for instance, as discussed in [this answer](http://physics.stackexchange.com/questions/33816/does-the-speed-of-light-vary-in-noninertial-frames)
Comment: @JLA: "My question is about light: Special relativity doesn't say anything about how light falls in a gravitational field, so if you are in a rocket ship accelerating at g ..." Einstein specifically said that SR is about **uniform** (i.e. unchanging rate and direction) movement. There are claims it is not true, but they unequivocally lead to so-called paradoxes (formerly: contradictions). I recommend you to check out my answer here (including the lengthy EDIT): http://physics.stackexchange.com/a/111471/43402. To sum up, accelerating ship is not an inertial frame of reference.
Answer: Special relativity does not say anything about gravitational fields at all, let alone how light behaves in them.  But it does say things about non-inertial frames, and therefore can quite happily predict how light will behave in an accelerated frame.
It is a common confusion about SR that it somehow can't deal with acceleration at all: it can.  SR is a theory which deals with spacetimes which are flat, and whether spacetime is flat or not is a property of spacetime, not of some observer, whether accelerated or not: all observers, whether or not they are accelerated, agree on the flatness of spacetime (if they do sufficiently careful measurements).  So an accelerated observer merely needs to do the appropriate coordinate transformations to and from their non-inertial frame, to an inertial frame to find out how light moves: as other people have said it moves along null geodesics.
The equivalence principles which underly GR are not important here.  However note that a 'uniform gravitational field' is almost an oxymoron: if a gravitational field is uniform then there is no curvature: it's just acceleration and it can be transformed away as above.  Gravitational fields in the sense GR talks about them -- curvature -- are never uniform.
The way to think about this is that frames are essentially choices of coordinate systems.  For all (sufficiently smooth) spacetimes you can choose, locally, some particularly nice coordinate systems where the laws of physics look very simple.  For some special spacetimes you can choose globally particularly nice coordinate systems.  These special spacetimes are ones which are flat, and they are the spacetimes which SR deals with.  But, for any spacetime, flat or not, you can choose coordinate systems which are not nice in this sense.  These coordinate systems correspond to the frames of non-inertial observers.
But the physics can't depend on the coordinate system: it can only depend on whether the actual spacetime is nice or not -- whether it is possible to choose these nice global coordinate systems: if it is, then SR works, if it is not, then it doesn't.
Answer: Your statement of the weak equivalence principle (WEP) is fine with me, but I think you're not applying it in the correct context.
Special relativity, as mentioned by @Jerry Schirmer, says that light travels along null geodesics. This meaning that it travels at $c$ since for a null geodesic the spacetime interval is null (zero).
$$ds^2 = - c^2dt^2 + dx^2 = 0 \implies \frac{dx}{dt} =c $$
In a locally flat space we can use special relativity to say that light will travel in this way.
Hope this clears things up some!
Comment: You didn't at all explain how the weak equivalence principle would tell how light would bend in an accelerated reference frame or gravitational field.
Comment: The question is almost a non-question. So I wasn't sure what to put as a response.

The weak equivalence principle posits that all bodies have the same "gravitational charge". Test particles of differing masses thus respond identically in a given field. Since this response (at least locally) is simply an acceleration we cannot distinguish the effect of the gravitational field from some other acceleration.

Since light would bend in order to reach you in an accelerated frame, the same is true in a gravitational field. Thus redshift, gravitational lensing etc.
Comment: I would think he nullified his own question by bringing gravitation into a SR problem. And I have to ask about the null geodesics. Using GR to derive SR?
Answer: Think of it this way:
Imagine you are in a rocket ship that has transparent portholes (very small ones) diametrically opposed on the body of the ship, and the ship is accelerating at g.   At some instant during flight, a laser beam pulse enters one of the portholes, and as soon as that event occurs, it is detected and another laser apparatus emits a laser pulse that crosses the cabin of the rocket ship at the same instant, alongside the one that entered the porthole.
Is there any reason that the laser pulse emitted from inside the cabin should not be deflected downward any less than the one that came through the porthole?  Make the rocket portholes be separated as far apart as it takes in order for the effect to be measurable.
This thought experiment even works if the laser was fired in some other direction (like from a spot on the ceiling of the rocket ship).  Additionally, clocks inside the rocket ship also slow down exactly the same amount they would on the surface of the Earth.
Answer: If you are in a flat space(time), i.e. without any source of gravitation, in a spaceship, and you emit a ray of light across the spaceship, both the spaceship and the light will be in the same frame of reference. The frame will be inertial - not accelerated - and therefore the light will follow a straight path.
Yet if a boost is applied to the spaceship, it means only the spaceship will be acelerated but not the light itself. Therefore light will still be in an inertial frame, while the spaceship will be in a non-inertial frame. That's why it appears to bend.
Now, if the rocket is given acceleration of 1g, i.e. equal to that on Earth, you will see exactly "the same thing happening as if you shined a light on Earth".
Answer: One of the greatest insights ever was Einstein's realization that locally a gravitational field is equivalent to acceleration. There are two caveats.. one is locally, and the other of course is that quantum effects are not involved. The result was General Relativity - a strictly classical description of gravity. Over 100 years later it's still the best we have, but it will need major change. Or indeed total replacement. The world is not classical.


Connection Between Liver & Honor?

Question: Seeing that lashon hakodesh allows for analyzing the connection between similar rooted words, what is the connection between liver (כבד) and honor (כבוד)?
Comment: Don't forget the word also means "heavy" or "serious" or "property"
Comment: Not that there has to be a connection, but maybe it's that the liver functions in a way which maintains the body's dignity/honor?
Comment: https://www.sefaria.org/Shenei_Luchot_HaBerit,_Asara_Maamarot,_Tenth_Maamar.8
Answer: Shemot 7:14 says:

וַיֹּ֤אמֶר ה' אֶל־משֶׁ֔ה כָּבֵ֖ד לֵ֣ב פַּרְעֹ֑ה מֵאֵ֖ן לְשַׁלַּ֥ח
  הָעָֽם
The Lord said to Moses, "Pharaoh's heart is heavy; he has refused to
  let the people out.

The word "kaveid" means "heavy" although I believe some translate this here as "stubborn" in the Torah. Why not say his heart was "kashah": "hardened" or "ikeish": "stubborn"?  One explanation is that "kaveid" also means "liver" and liver must be broiled and the more it is broiled, the harder it becomes. Usually, when a stubborn person is beaten and punished, his heart softens and he begins to concede and yield. So the Torah is telling us that the heart of Pharaoh was like liver: the more plagues he received, the more stubborn he became.
(מיוסד על מדרש רבה שמות, ט,ח)
That was an interesting fact from the Torah and Sages to tie it altogether with the other translation "heavy" as some in the comments noted.

To answer your question:
So how does "liver" relate to "honor"? Your liver is the hardest working organ in your body, performing over 500 life-sustaining functions. It is the largest internal organ in the body and filters toxins from your blood, produces digestive enzymes called bile, stores vitamins and minerals, regulates hormones and the immune response and helps clot blood. Your liver is the only organ in your body that can regrow after parts of it have been removed or damaged. In fact, your liver can grow back to its full size in just a matter of months.
Can you live without the liver though?  NO.  The liver is so crucial to existence that while you can live with only part of a liver, you can't live without any liver at all.
In fact, we can live without various body organs... but not without the liver.  Just as we cannot survive without our livers, we cannot have success in our lives or survive without any honor.  But perhaps a lesson to take from the connection between "honor" and your "liver" is that just like how if you lose a part of your liver it can regrow... so to if you lose a part of your honor it can be regained.
Comment: Can you please provide a source from where that is derived @YaacovDeane?  Thanks!
Comment: If you're asking about the מל״ך, מוחין, לב, כבד concept, that was from the Lubavitcher Rebbe in one of his earliest public talks. It was within the first 3 years of his Nasiyut. I'll have to pull out a couple of seforim when I get home to provide an exact page reference. The Nefesh being in the blood is Bereshit.
Comment: @YaacovDeane, yes about the מל״ך, מוחין, לב, כבד concept.  No need to pull page reference, thank you.
Comment: What you relay about the liver is accurate, but the primary function of the liver related to the 'heaviness' of Pharoah's heart and its becoming 'hard' is that the liver produces the proteins which cause blood, which is the place of the Nefesh, to coagulate, meaning to transition from a fluid into a solid. This ability to transform into a more material state is why the liver (כבד) is the final letter of King (מל״ך). The concept of Melech HaMoshiach, revealing G-d's Kingship in this physical, material world, is related to Brains (מ״וחין), Heart (ל״ב), and Liver (כ״בד).
Comment: If you're asking about revealing G-d's Kingship in this physical, material world, that is the concept of דירה בתחתונים like is discussed in the Ma'amar, באתי לגני at length.
Answer: "Kaved" is "heavy." Liver is the heaviest internal organ. Something honorable has figurative "heft." Done.
(Rabbi Joseph Dov Soloveichik had a lecture about yeshiva students taking secular studies entitled a koved or a kavod? ["burden or honor"])

Connection Between Liver & Honor?


What is proper email etiquette after a coworker accidently sends a "reply all" message to a large number of people?

Question: I think we all know that moment... A coworker inadvertently sends a "reply all" email instead of replying to one individual, and he/she doesn't realize it went to a large number of people. What's worse is that the message was clearly not meant to be shared broadly and was a snarky response about someone on the thread.  What is the best way to deal with situation? Do you tell the coworker he/she has shared information broadly? Do you pretend it didn't happen? How should the sender remedy the situation? With another reply all?
Comment: [Never reply all to a reply all.](https://en.wikipedia.org/wiki/Email_storm)
Comment: Just ignore it.
Answer: Two tips:

Don't reply-all. I've been in e-mail threads of 100+ e-mails with people saying "Unsubcribe", "Please don't reply-all", "Please everyone stop replying all to the 60,000+ person company mailing list", etc....
Don't reply to them. They made a mistake, lots of people are correcting them on it. Probably by reply-all or sending them a message.

Do you pretend it didn't happen? How should the sender remedy the situation? With another reply all?

Ignore that it happened. The sender should ignore that it happened too.
I give these answers because: more communication on top of mass spam does not make the receivers happy, many people understand mistakes happen (a few wrong keystrokes or auto-complete gone wrong), most confidential material that may be contained in the Reply-All is probably going to people with a non-disclosure contract, and in general I don't care if I get e-mailed something I shouldn't as long as people don't keep reply-all'ing or e-mailing me.
Comment: In the UK, someone managed to send an email to everyone in the NHS. 1.2 million emails. And enough people pressed "reply all" to bring their systems to a stand still.
Comment: @Walfrat The particular incident had 40k-120K people and 200 emails in the REPLY-ALL tree (unknown how many direct e-mails were involved). Our e-mail system automatically cut off the tree at 200.
Comment: red too fast, and I didn't noticed the date of the posts too.
Answer: It's the sender's problem - stay out of it. Don't do anything.
Your colleague is going to find soon enough from a number of people that he/she made a mistake. It's a mess and you'd best help your coworker by not adding to their predicament.
The sender is going to have apologize to that someone on the thread that they were snarky to. And pretend that the rest of the world wasn't cc'ed.
Answer: I had a similar situation recently, on a smaller basis.
A co-worker did a reply all without realizing that a client contact had been added to the message, and made a somewhat tactless comment about that person. When I brought them some paperwork a few minutes later, I asked if they realized what they had done.
However, if the sender is not someone you work with closely, or there are more than a dozen or so people that the message was sent to, as the other answers have said,  I would just ignore it.


Can I legally build and sell desktops with Ubuntu pre-installed?

Question: I'm starting a business and this is part of what I'm going to be offering. I'm almost complete with my certification in Linux Administration, but I don't know all of the ins and outs of the law Linux is under...
Answer: It depends. Ubuntu is free software (beyond some redistributable binary blobs), but if you're using it for commercial purposes there are trademark restrictions.
The Legal Fine Print

Permission from us is necessary to use any of the Trademarks under any circumstances other than those specifically permitted above. These include:

Any commercial use. OEM services. [...]
Use for merchandising purposes, e.g. on t-shirts and the like.
Use of a name which includes the letters BUNTU in relation to computer hardware or software.

Source: Ubuntu Trademark Policy

Hardware with a debranded Ubuntu OS
If you remove all branding, trademarks, and references to Ubuntu, you are legally okay to sell systems with it installed. Of course, you must provide the source code of all GPL components to customers that request it.
Hardware shipping with Ubuntu "as is"
To use the Ubuntu trademark, you must secure the Canonical's OEM services team's  permission. You can contact them to see if what you're doing is okay. This should not be too difficult, as several small vendors like System76 and ZaReason have secured an agreement.
Comment: Does the branding within the OS actually count as "using" the trademark if it's not mentioned in any of your marketing materials?
Comment: @Random832: No. A trademark is the "exclusive right to use the registered mark _in commerce_" (§1115 Lanham Act)
Comment: http://www.iusmentis.com/trademarks/crashcourse/limitations/ says "Also, trademark rights are exhausted when a trademarked product lawfully enters the market. The trademark holder then normally can no longer act against resale of the trademarked product.". OP should probably ask a real lawyer, though, particularly if he has any intention of doing this without getting permission.
Comment: Do you know much it will cost to sell a smartphone with Ubuntu Touch OS installed for the vendor to pay to Canonical? I was proposing an idea for ZTE to provide an Ubuntu OS option to be preinstalled on their phones. If we get enough vote, ZTE can release an Ubuntu phone for consumers to choose. But I am not sure about the cost. See https://community.zteusa.com/ideas/1869
Answer: It is completely legal to sell a computer with Ubuntu preinstalled. It even lowers the cost.
It is also legal to sell CDs/DVDs with Ubuntu in them.
In both is legal because you are not selling Ubuntu, you are selling the hardware that comes with it. In the case of the PC, you are selling all that hardware that comes with Ubuntu so the end user does not need to worry about the many problems in Windows (Or the costs in Mac).
With the CD/DVD, you are selling the cost that you had to pay to have the CD/DVD. Burning the CD/DVD also has a cost as well as having a design printed on the CD/DVD.
If you worry about this, what you need to know is that the only thing illegal here is to charge directly for Ubuntu as it would something you made.
The laws of Freedom explicitly state:

Freedom to run the program
Freedom to access the code
Freedom to redistribute the program to anyone
Freedom to improve the software

These are freedoms oriented to what you can do with information, not how the information got to you. So charging for a CD of Ubuntu that you downloaded, burned, made a printing design on it, put on a plastic cover that you also bought with that nice logo you wanted to use is totally okay. Same goes for that computer you bought in pieces, assembled them, install Ubuntu and upgraded it. Installed additional tools for the end user. Tested the PC for 2 days to make sure it was perfect for your buyer. And then sold it to the buyer is also OK. You are actually charging for the work you put to offer this to the end user. Your client.. and after having Ubuntu installed in it he/she would be.. your happy client.
To give you a better feeling about this, you can see as companies like Dell, Asus and others sell Laptops with Ubuntu installed. Several universities offer CD/DVD with Ubuntu in them for a low price. Even events like Flisol offer installing Ubuntu (In this case free) since they can install it directly to the client or with a cost if they need to give out a CD/DVD of it (Of course since most of us pitch in, the cost of the CD/DVD for the new users is free).
UPDATE - AS mentioned by popey, there are a couple of things you need to read:
OEM Services (Read the WHOLE thing) - http://www.canonical.com/engineering-services/oem-services/oem-services
Trademark Policy - http://www.ubuntu.com/aboutus/trademarkpolicy
For the trademark, as long as you do not use a extensively modified version of Ubuntu (Extensive as in changing the directory structure, modifying many basic tools and programs, changing names, etc) you will not have a problem with the trademark. In your case where you only mention the installation and configuration of Ubuntu you won't have problems with this.
UPDATE 2 - As mentioned by drewbenn in his comment here is a good link about this: https://www.gnu.org/licenses/gpl-faq.html#DoesTheGPLAllowMoney which complements the rest mentioned in the answer.
Comment: `It even lowers the cost.` - I guess you mean, that it lowers the costs, compared to an installed Windows, not compared to a plain blank PC? That might not be true. PCs are often preinstalled in great numbers, so there isn't really an installation process, but just big numbers of harddrives copied from machine to machine. A manual installation of a few Linux PCs will take much more time, if you have to do it yourself or if you have to pay somebody to do it. You save the license fee, but you have opportunity costs.
Comment: You also need to take account of the trademark policy http://www.ubuntu.com/aboutus/trademarkpolicy
Comment: @popey - Very good point. I will add the important parts I see from there and the OEM Services.
Comment: For the user asking the question and for me it lowers the cost since we do not need to buy a windows license. In both cases we want to install the Os but to install it, in windows case I need to buy it, in Ubuntu I need to download it ^^. 100$ less. With regards to installing Linux on several PCs, it would take less if compared to Windows, in Linux you can actually dd in a network with several tools. So it would take you the same time to install it on 100 PCs that on 5 since it would clone itself via the network with a very easy and fast setup on each PC.
Comment: +1 @drewbenn - Very good point. I will add it to the answer. You hit the spot there.
Comment: Where did you get this: "[...] what you need to know is that the only thing illegal here is to charge directly for Ubuntu as it would something you made." ?
Answer: Linux is protected both under copyright law and trademark law, as is Ubuntu. The GPL and similar Open source licenses give specific permission to copy Ubuntu software, as required by copyright law.
That leaves you with trademarks. Under the doctrine of nominative use, you are specifically allowed to use the Ubuntu trademark to describe Ubuntu. Trademarks are intended to signal that your customers get the "real deal" and not something that's just similar to Ubuntu.
You may not over-use the Ubuntu trademark. I.e. you cannot suggest that your hardware is also part of Ubuntu, that Ubuntu is optimzied for your hardware, or use their logo.
Jacob Johan Edwards suggests that Canonical imposes restrictions on the commercial use of the Ubuntu trademark. However, federal law does not give Canonical the right to impose restrictions on the legal use of trademarks.
Answer: Selling computers with Ubuntu pre-installed is actually not as clear-cut as others have explained. You should read the Ubuntu trademark policy specifically the parts under "Restricted use that requires a trademark licence". Note for example

Permission from us is necessary to use any of the Trademarks under any
  circumstances other than those specifically permitted above.
  These include:
  Any commercial use.

Selling a computer with Ubuntu pre-installed is "commercial use".
Comment: Not actually.  The "commercial use" refers to *use* of the trademark.  So don't refer to or use the Ubuntu trademark in a way that suggests you are affiliated with Canonical, but go ahead and sell the computer with pre-installed Ubuntu.
Comment: @jrg This flies in the face of how trademarks typically work.  It won't be the first time a company has claimed extra privileges on their trademark beyond what the law gives them.
Comment: @jrg That's the sad thing.  The only reason, seemingly, that people are thinking there's a "fine line" is that Canonical is being overly aggressive here.  The idea of [nominative (fair) use](http://en.wikipedia.org/wiki/Nominative_use) of trademarks is well-established.  You can even [sell Lexus-brand cars from a domain name using the word "Lexus"](http://www.ca9.uscourts.gov/datastore/opinions/2010/07/08/07-55344.pdf) without permission (there's no way to describe the service without using "Lexus", they do not use the symbol, and there's a disclaimer distancing themselves from Toyota).
Comment: @Chan-HoSuh Since Popey is a canonical employee, I'm more inclined to defer to his answers.
Comment: @Chan-HoSuh Regardless, you would be toeing a fine line. It's just easier and safer to talk to Canonical first, and then go from there.
Answer: Vanilla Ubuntu: You should be fine.
But if you install some more software on to it, like proprietary software you are not allowed to distribute, then maybe not.
Comment: What if the software is free to install? E.g. an office suite or a music player.
Answer: Dell and Christmann (just to name a few) do what's asked in the first question. So yes it is legal to install Ubuntu and then sell the Computer - as long as you don't charge for something you don't have the rights to.
My University did sell CDs with Ubuntu on them. So yes, that's legal too.
Comment: Because Universities can't do wrong?
Comment: Or they get a license or permission before-hand. That does not mean just anyone is allowed to sell it without doing so before-hand.
Comment: No, but good ones usually check very carefully before they do such a thing.
Answer: I think Ubuntu is mostly GPL software, so the right to distribute it can't be restricted by license or trademark policy.
So you can install Ubuntu on an assembled PC, and it can't be prohibited to sell it. Now as a dealer, you have to inform your customer what you want to sell them. So it can't be prohibited to tell them, what you've installed on the hardware.
Of course in your acting you have to avoid the impression that you're acting in the name of Ubuntu, as part of the company behind Ubuntu or using their logo.
However, as a nice guy, I would tell them what I want to do.
Comment: [Canonical explicitly disagrees](http://www.ubuntu.com/legal/terms-and-policies/intellectual-property-policy) with your position that the right to redistribute mostly GPL software can't be restricted: _The disk, CD,  installer and system images, together with Ubuntu packages and binary files, are in many cases copyright of Canonical (which copyright may be distinct from the copyright in the individual components therein) and can only be used in accordance with the copyright licences therein and this IPRights Policy..._
Answer: It's possible...but you have to check that you are shipping your machine with proprietary software...If so then you have to get permission from respective owners...
Answer: I don't know what they are trying to say but as a linux user as well as developer I ensure you one thing There are some distribution of unix os that are made free for everyone and many struggled for this. So, I suggest use any of the free distribution and I request not to charge for the os but its up to you.
Answer: You can sell machines with Ubuntu pre-installed ,but you are not able to charge your customers for the operating system.
Comment: Can you back this up somehow? It's not at all clear to me that Ubuntu's license(s) prevent you from selling it, or that "selling Ubuntu" and "selling hardware running Ubuntu" are that clearly distinguished, legally speaking.
Comment: @Oxwivi: Re-read the GPL, the most restrictive of the open-source licences. You're perfectly free to sell such software if you want, no matter what Canonical might say. However, you probably have to change the name due to Canonical's trademarks. Who owns the copyright is irrelevant, unless the binary blobs are an impediment. As for RHEL, last I knew it included some closed-source RH software. So it's a whole different beast. All Canonical software in Ubuntu is open source.
Comment: @Oxwivi http://www.gnu.org/licenses/gpl-faq.html#DoesTheGPLAllowMoney
Comment: I understood that much, but it's nice to know I wasn't wrong. Thank you for the verification.
Comment: For most (all?) free software licenses, you're free to charge money if you want, but you might have to make the source code available at no charge. But I don't know about the binary blobs.
Comment: @ScottSeverance you're free to charge **if** you own the copyright. I can't legally sell Ubuntu cause it's an IP of Canonical, just RHEL is an IP of RH (so they sell). Well, maybe the word copyright isn't the correct (since there's copyrights of the original authors of free codes involved), but you get the idea.


What to use instead of credit cards in Iran?

Question: I've read that it's not possible to pay for stuff by international credit card like debit cards. What do you recommend to do in such a situation? As far as carrying a lot of money is not safe at all.
Comment: @mouviciel I am Iranian, and neither I nor any of the people that I know are in the habit of carrying large amounts of money! FYI, we use credit cards!
Comment: @PeterHahndorf You are right, but my comment was mainly in response to the following comment which was removed by its owner: _"All Iranian people carry a lot of money when shopping"_
Comment: @Meysam - but you are using Iranian cards? as far as I know US card companies like Visa or Master card to not work in Iran.
Comment: @PeterHahndorf: Yes, that's the problem!
Comment: @mouviciel Iraninan credit cards will not work outside Iran (maybe in Syria), and international cards will not work in Iran. Why? See my answer. Until you deal with your government it is unlikely to change.
Answer: One option would be to bring cash with you, convert it to Iranian currency and then buy something called "Gift Card" from a bank. You can easily obtain them from most of the well-known banks without having an account. You can use these cards to buy stuff almost anywhere within the country. They are also password protected and only the owner can use them. In case you lose them or get them stolen, you can contact the issuing bank to block the missing card and get another one.
This is just one of the ways that can help you avoid carrying money. There might be other ways too :)

Update: A new card has recently been introduced called Tourist Card:

Bank Melli, Iran's first national bank, plans to issue a debit card
  exclusively for foreign tourists visiting the country.
Issued under the title 'Tourist Card', visitors can apply for the
  charge card at the Bank Melli branch of Imam Khomeini International
  Airport, said a report in Tehran Times.
With all charges converted and billed in the local currency, the card
  limit will be set at $5,000 or €5,000.
The tourist card will be valid for the length of stay of the visitors
  and any remaining money in the card will be reimbursed, the report
  said.
The card can be used at the issuing bank's ATM's across the country as
  well at points of sale (POS) and online shopping.
The bank plans to issue the cards in more than four Iranian cities,
  which are yet to be determined, the report said.

And here is the official website of Iran Melli Bank, which has fully introduced this new card:

It is a card in Iranian Rial which is issued for tourists against
  foreign currencies received from them with designated expiry date and
  it can be used in whole Iranian banking system.
A Tourist Card is given to clients with exclusive passwords. There are
  two passwords for each card. First password is to be used when the
  card is used to buy by POS and the second password is used for
  internet buying. Both passwords can be changed by the holder of the
  card.

Specifications of Tourist Card:

It can be used through whole Iranian banking system
Cash can be withdrawn only in BMI ATMs.
Funds can not be transferred to Tourist Card
Cards can be used to buy through internet, their passwords can be changed and funds can be transferred from Tourist Card to other cards.
The remaining cash in Tourist Cards can be converted to foreign currencies and paid to customers.
The expiry date of Tourist Card will be the date when clients' visas are expired.
The limit of charging these cards in $ 5,000
Customers can be informed about the remaining balance of Tourist Cards through Bank Melli Iran's website (www.bmi.ir), all ATMs throughout the country and all POS systems.
Customers can take billing statements and be informed about the breakdown of their Tourist Card transactions in BMI ATMs.
Comment: Is it possible to get the balance back from those? I know in the US these cards are not refundable and come with hefty fees, so if the OP has 200 EUR on a card, but only use 100 EUR - the rest is gone forever (as this is an Iranian card - its unusable anywhere else). What are the rules in Iran in such case?
Comment: @littleadv It's always possible to get money from ATM with these cards. So the rest of money can be considered refundable.
Comment: Ok, +1, but for the OP: do take the fees and the conversion rates into account. And you'll have to bring the cash with you, in any case (unless Iranian pre-paid cards are sold in Turkey, which I doubt in face of the financial restrictions on Iran).
Comment: For this card the bank will likely use the official exchange rates, which are way worse than what you can get on the street. (I think it's a 20-ish percent difference, at least!)
Comment: @Bas There is no need to do the exchange in the bank
Answer: No Visa, MasterCard, etc do not work in Iran. There is a national debit card system called Shetab. And all the Iranian banks and many credit unions are members of Shetab. So basically if you buy a Shetab card from any bank, you will be good. Bank Pasargad is one of them. And here is a page that shows a bank Pasargad gift card.
However, You cannot buy it online. Once you land in Iran, you may exchange your foreign currency to IRR (Iranian Rial) and buy a gift card either at the airport or ask your hotel reception to help you get one.
Answer: With the latest sanctions against Iran (i.e.: SWIFT disconnecting them), cash would be your safest bet.


Small notes on the staff

Question: What are these and how do I play them on the piano?
Comment: It's not that well written. There's no need to tie 2 quavers together in bar 7 where a crotchet will do.
Answer: What they are:
Based on your question, you just want to know how to play them. While there are theoretical squabblers, just ignore the people go super into the theory.
It turns out there are two types of these small notes, and they get confused a lot.

Appoggiatura (no strike-through)
Acciaccatura (strike-through)  Also known as "Grace notes"

What you're seeing in that piece are Appoggiaturas. They aren't grace notes. A grace note is actually a slang term for  'Acciaccatura' note which has a strike through. An appoggiatura does not have any strikethroughs. This might sound complex, but it's actually very simple, let's break it down with pictures!
Appoggiaturas:

Small notation
No strike-through
Takes half value of connected note (longer value than Acciaccaturas) and played on beat

Acciaccaturas "Grace Notes":

Small notation
Has a strike-through
Takes a VERY short value of the connected note (1/64th)
Can be played both on or before the beat depending on composer/context

TL:DR No strike through = half value, LONGER | Strike through = very short
I hope this helps! If it answers your question, please mark as answered to keep up with maintenance. :)
Comment: Could you please also extend info about whether acciaccaturas or appogiaturas take the accent from (i.e. are stronger than) the connected note? Just asking interested, assuming it does despite its size in print.
Answer: These are called grace notes. Some good, already-written answers on this site can be found at Different types of grace notes and What do these grace notes mean, and how do I sing them?
Answer: These are called appoggiaturas, which are a type of grace note. These should be played on the beat of the note that they precede, and will (usually) be played for half the length of the main note.
Comment: It's not an appoggiatura.  Appoggiaturas are approached by a leap and resolved by a step.
Comment: Appoggiaturas generally resolve by step, though it isn't strictly essential.  They certainly don't have to be approached by a leap.   Anyway, we're confusing points of Baroque/early Classical style with the question of what that particular notation is called.  They're called appoggiaturas.
Answer: Technically they are appoggiaturas, to be played on the beat taking half the length of the main note.  A melodic suspension.   The ones with a slashed tail are acciaccaturas, to be played as a short decoration to the main note.
But as the musical "grammar" of the example shown is so haphazard, I wouldn't be too sure the composer had the slightest idea what he wanted!
Comment: Don't worry too much about the example score, it's musically illiterate.  But Dom is falling into the old trap of thinking that theory commands.  It merely describes.  Appoggiaturas conventionally resolve by step.  Approach by leap is less set in stone, even the relevant Wikipedia page offers an exception.
Surely we can allow these examples the name "appoggiatura", even if they don't quite satisfy some old book of rules?

http://henry43.co.uk/appog.PNG
Comment: @LaurencePayne I'm not falling for any trap as when you call something X, it needs to be X. The ornament the appogitora is tightly coupled with the  definition of it as a non harmonic tone which it always is [aproched by leap and resolved by step in the opposite direction](http://www.ars-nova.com/Theory%20Q&A/Q93.html). No trap just a definition and misusing terminology is the reason why most people get really confused about theory and notation.
Comment: It's not an appoggiatura. Appoggiaturas are approached by a leap and resolved by a step.
Comment: @Dom.  I know that's how they are usually used but can you cite  a source that says that it must be so?  And if it is the case do you know what this - the OPs example grace note - is called?
Comment: @LaurencePayne your examples along with the OPs are also missing the slur which is extremely important for an apporigtora .

Small notes on the staff


Was The Beatles' "Yellow Submarine" the first released record to contain a sample of another released record?

Question: The Beatles' Yellow Submarine contains a cut-up of a Sousa march that apparently came from another record (as described in http://www.beatlesebooks.com/yellow-submarine). Was this the first instance of a released record sampling another released record?
Answer: It looks like sampling predates the Beatles somewhat.

In 1924, Italian composer Ottorino Respighi premiered his symphonic poem, Pini di Roma (Pines of Rome).  In this piece, many scenes from the natural and civilized world are portrayed with symphonic instruments, such as an organ and various brass instruments playing low pitched notes to represent the catacombs.  The third scene, I pini del Gianicolo, features the song of a nightingale. Rather than conjuring images of a nightingale with a flute, Respighi decided to just cut to the chase and play a recording of a nightingale.
Although neither Respighi nor his audience could have any idea this performance had broken ground on a technique that would transform music in the 20th Century, this was probably the birth of sampling.  He took a portion of a previous recording and incorporated it into a new performance.

A brief history of sampling
Most other sources seem to give Musique concrète the credit for sampling starting in the 1940's.
As far as sampling from a released record is concerned, the first example isn't valid (as it was a recording not a release ) but the second points towards the setup using record players:

In 1948, a typical radio studio consisted of a series of shellac record players, a shellac record recorder, a mixing desk, with rotating potentiometers, a mechanical reverberation, filters, and microphones.

So maybe we can assume that 'released' recordings were used.
Comment: As you say, obviously sampling *itself* goes way back before the Beatles, though I hadn't read that story of  Musique concrète's 'birth' before!
Comment: The link to "A brief history of sampling" seems to be broken, could you check it, please?