Buddhism to change the world

Question: According to Buddhism, should one change oneself or change the world and why.
Comment: Please clarify, are you trying to plot "fight for truth, freedom, justice" against "reduce Dukkha" ? Please clarify what you are trying to ask. Ask directly also helps... no need to play with words. And no need to evolve your question based on my answer.
Comment: Changing oneself and changing the world aren't mutually exclusive. Unless one is a hermit living completely isolated from the world, a layman who "changes himself" by observing precepts, practicing meditation, etc. would make a correlated positive impact on the world due to the positive effect on other people from his 3 gateways: mind, body, and speech.
Comment: @PbxMan Once again, this is not a web forum. Please keep your questions to the point. "According to Buddhism, should one change oneself or change the world and why" - that woud be enough. Thanks.
Comment: @AndreiVolkov don't worry all take it another forum. I cannot delete from here. Would you please do that for me?
Answer: The Buddha did not intend monks to participate in politics, as seen in DN 2:

"Whereas some brahmans and contemplatives, living off food given in
  faith, are addicted to talking about lowly topics such as these —
  talking about kings, robbers, ministers of state; armies, alarms, and
  battles; food and drink; clothing, furniture, garlands, and scents;
  relatives; vehicles; villages, towns, cities, the countryside; women
  and heroes; the gossip of the street and the well; tales of the dead;
  tales of diversity [philosophical discussions of the past and future],
  the creation of the world and of the sea, and talk of whether things
  exist or not — he abstains from talking about lowly topics such as
  these. This, too, is part of his virtue.

However, the Buddha did intend for lay people to participate in constructive nation building, in accordance with the Dhamma in DN 16:

At that time the Venerable Ananda was standing behind the Blessed One, fanning him, and the Blessed One addressed the Venerable
  Ananda thus: "What have you heard, Ananda: do the Vajjis have frequent
  gatherings, and are their meetings well attended?"
"I have heard, Lord, that this is so."
"So long, Ananda, as this is the case, the growth of the Vajjis is to
  be expected, not their decline.
"What have you heard, Ananda: do the Vajjis assemble and disperse
  peacefully and attend to their affairs in concord?"
"I have heard, Lord, that they do."
"So long, Ananda, as this is the case, the growth of the Vajjis is to
  be expected, not their decline.
"What have you heard, Ananda: do the Vajjis neither enact new decrees
  nor abolish existing ones, but proceed in accordance with their
  ancient constitutions?"
"I have heard, Lord, that they do."
"So long, Ananda, as this is the case, the growth of the Vajjis is to
  be expected, not their decline.
"What have you heard, Ananda: do the Vajjis show respect, honor,
  esteem, and veneration towards their elders and think it worthwhile to
  listen to them?"
"I have heard, Lord, that they do."
"So long, Ananda, as this is the case, the growth of the Vajjis is to
  be expected, not their decline.
"What have you heard, Ananda: do the Vajjis refrain from abducting
  women and maidens of good families and from detaining them?"
"I have heard, Lord, that they refrain from doing so."
"So long, Ananda, as this is the case, the growth of the Vajjis is to
  be expected, not their decline.
"What have you heard, Ananda: do the Vajjis show respect, honor,
  esteem, and veneration towards their shrines, both those within the
  city and those outside it, and do not deprive them of the due
  offerings as given and made to them formerly?"
"I have heard, Lord, that they do venerate their shrines, and that
  they do not deprive them of their offerings."
"So long, Ananda, as this is the case, the growth of the Vajjis is to
  be expected, not their decline.
"What have you heard, Ananda: do the Vajjis duly protect and guard the
  arahats, so that those who have not come to the realm yet might do so,
  and those who have already come might live there in peace?"
"I have heard, Lord, that they do."
"So long, Ananda, as this is the case, the growth of the Vajjis is to
  be expected, not their decline."
Answer: AN4.95 clearly lists the priorities of practicing to help oneself vs. others:
Not so good:

One who practices to benefit neither themselves nor others;

Better:

one who practices to benefit others, but not themselves;

Even better:

one who practices to benefit themselves, but not others; and

Best:

one who practices to benefit both themselves and others.

Notice that practicing to become a better person is seen as having more benefit that telling others how to practice. It sounds odd until you think about it, but when you think about it, would you follow the example of one who does not practice what they preach?
Hence it is best to practice and help others practice, but it's also ok to just worry about your own practice until you can help others.
Answer: Buddhism is not a religion that tries to change the world I think. Just like Buddhism don't give direct explanations of the nature of the universe. Buddhism's purpose is to lead people to experience the nature of reality themselves and give proper guidence to the people who have the intention to free themselves from suffering.
I remember a dhammaphada verse(thousands) that is not directly connected to this topic but I think it can give us some insight about Buddhism's approach to this subject

Greater in battle than the man who would conquer a thousand-thousand men, is he who would conquer just one — himself.
Better to conquer yourself than others. When you've trained yourself, living in constant self-control, neither a deva nor gandhabba, nor a Mara banded with Brahmas, could turn that triumph back into defeat.

If a person is interested to the core of Buddhism(meditation) most likely s/he  becomes less interested to changing the world, because meditation leads people to realize that trying to change or help others can be an ego demand and most of the things in the world are out of our influence. Also trying to change the world without changing oneself can cause harm to others because a person's state of mind directly influences the quality of his/her actions. But that doesn't mean that everyone who are deeply involved with meditation are less interested to changing the world. Trying to change the world can continue in the meditators as a habit even If the meditators greatly purify themselves. Meditation leads people to become more aware of the suffering of other living beings, so it is possible for a Buddhist meditator to become interested to change the world but eventually that desire would be diminished because of the realization of the uncontrollability of the forms and the degree of craziness of the humans.
Buddhism is not a political movement, don't have "Sharia Laws", don't try to conquer the world, forcibly trying to change an individual's desires or have rules that restricts people's freewill so it is up to the individual to decide to interfere the world politics or try to change the world or not. But "doing good deeds" to other people and living beings is certainly what Buddhism directly recommends to it's followers but that is not the same thing as trying to change the world I think.
Answer:
that's a clear example of somebody who needs to work with their inside.

Anyone who acknowledges Dukkha (Suffering) and wants to eliminate as such, need to work with their inside.

According to Buddhism is it bad for her to try to change her external conditions or perhaps she is encouraged to do so because after all she is taking action for the everybody's well-being?

Another xxx VS xxx....
It is for her to decide. Is she experiencing Dukkha? Does improving her external conditions directly lead to less Dukkha? If yes, Go for it. How about improving the inner conditions first?
Whether her external conditions prevents her from improving her inner conditions, is a different matter of fact and cannot be determined unless you articulate the exact situation.
Comment: This answer doesn't make sense now after the question was edited.
Comment: Yes. Pbxman kept changing the question after I posted the answer. He even deleted his account now. Probably just trolling and realized its much harder than he/she thought...
Answer: If the world has many problems, it is up to the people of the world to sort out those problems rather than Buddhism.
I may be a Buddhist in this world and thus choose to not purchase sweatshop goods or choose to not support certain politicians, which may include not supporting the government of the nation I live in.
However, every other person, be they Buddhists or non-Buddhists, must also contribute to this. If others do not join in the path of goodness then I alone cannot change the world (even though my own Buddhist actions are moral & harmless).
For example, if I have a problematic neighbour, I sort out the problem. I talk to the neighbour or go to the police or go to a court of law. I do not wait for a Buddhist in a Superman outfit to save me from my bad neighbour.
Similarly, while illegal immigrants should not enter into the USA or any other sovereign nation, if this is really a major issue, it is up to the American people to sort out this issue. It does not require SuperBuddha to save the day, like in a Hollwywood movie.
The girl working in the sweatshop can try to educate herself and move out of the sweatshop. Regardless, it is American companies operating most of these sweatshops and the American people buying most of the sweatshop goods. America is a democracy. People can boycott sweatshops and lobby to have clothing made again in the USA. If people do not think importing all of their goods is a problem then that is the will of the people; just as it is the will of the American people to destroy nation after nation in imperialist wars. SuperBuddha cannot stop this.
In short, these political matters are for the people of the world to sort out. The people of the world may include Buddhists. But Buddha is not a SuperBuddha from a Hollywood movie.
Answer: yes people who want to change the world and babble about revolutions and are obsessed with rights completely fail to understand that nobody can be forced to be mindful nor being secluded from sensuality and that there is no punishment to forbid non-mindulfness and so on.
The people who love the idea of helping people do not even manage themselves to be mindful for more than a few hours, yet they have no problem fantasizing themselves has been good people able to make other people better.
 It is part of their insolence of claiming to know the dhamma, when all they do is being infatuated to the toxic pile of garbage that is the aggregates, always trying to salvage sensuality by claiming that  sensuality is skillful, always daydreaming and building stories that deep down in their heart, they are not bad people already, so that they leave room for a little improvement in order to have  a purpose in life, because daydreaming about not changing their ways is all they have in their life.
When they see that they have no skills to better themselves, they long for some external source of improvement which would make everybody better.
In fact, most of the people addicted to sensuality do not want to stop clinging to sensual pleasures. Some of those people  even claim that nibanna would be the most horrible event to happen to anybody.
Answer: If Buddhism has taught me anything, it's that you can't engineer happiness.  Real joy in this life comes only by a wholehearted engagement with emptiness.  Any attempts to engender joy, no matter how valiant, are ultimately impermanent.  Institutions wither, people die, and the enthusiasm that burns so brightly at the heart of many social programs ultimately burns out.  Worse, no intentional act, no matter how pure in intention, is wholly wholesome in its impact.
I remember when I was a kid and working at a coffee shop.  This well dressed, well spoken man used to come in all the time.  Apparently he used to be a doctor in the country he grew up in.  His medical license didn't transfer, so now he was studying up to take his exams in America.  The man was a saint.  He was kind, generous in spirit, and just a pleasure to be around.  He once was named Mr. Barbados back in his home country and was very interested in bodybuilding and weightlifting - an interest I shared with him.  Everyday he'd come in and ask me how my workouts were going.  He even came to see me lift a few times at some powerlifting meets.
I saw this guy pretty much everyday for a year.  One day he comes up to me and says that he needs me to proctor a test for him.  I agree.  He tells me, "don't worry about me cheating, I'm a Jehovah's Witness.  We don't cheat!"  I was flabbergasted by his admission.  If you know anything about this sect of Christianity, you'll know that bearing witness - essentially proselytizing - is at the heart of their practice.  I never heard him mention a peep about it.  I asked him about it.  "Good sir," he says to me, "do you think I would cheat?"  I tell him no.  "Do you think I am a good man?"  I said of course.  "Are you happy to see me when I come in?"  Absolutely, I said.  "That is my witness.  That is my light of Christ."
Atta dipa.  Be your own light.  We can only illuminate our own way and let that brightness shine on the paths of others.  What will be your witness?  How will your light shine in the world?
Answer: One cannot change the world.
One can only change oneself and that is done by practicing the Dhamma.

Buddhism to change the world


What is the expiration date of patent US9474214?

Question: What is the expiration date of patent US9474214?
Answer: The best way to determine the expiration date of a US patent is at the US Public Pair site. Go to Pair, get past the CAPTCHA and then select "Patent Number" and enter 9474214. Pair is extremely picky about format so don't add any commas. From there you can find that this patent will expire 20 years from it's filing or 371(c) date of 09-07-2012 plus 523 days of patent term adjustment. If I calculate correctly that ends up with an expiration date of February 12, 2034.
Comment: We almost need a general, self-answered question on this topic *(although I suspect very few OP's actually search for prior questions;)*
Comment: @DukeZhou Agreed. Why don't you take a whack at it. If you make it a public wiki, then others can add content. For instance, I have a good take on US patents, but I'm not sure if there are things like patent term extensions for foreign patents or how to find out.


Sharing audio interface (external sound card) with two computers on network

Question: I have Audioengine A5+ speakers connected to the main output of a USB audio interface, which is in turn connected to a Windows computer on the LAN. Could I share this USB audio interface with another Windows computer on the same LAN and send audio from that computer to the same external sound card?
Comment: You could try NetJack or NetJack2 and the [Jack audio connection kit](http://jackaudio.org).
Answer: Depending on your latency requirements, there are a wide variety of network audio protocols that may suffice for this application. Essentially, both computers would have "virtual sounds cards" which pipe to and from the network. Specifically, you want layer 3/4 protocols that will operate with standard COTS networking equipment.
Examples of these protocols which are open standards are AES67, Ravenna, and NetJack. There are also proprietary protocols like Dante and Q-LAN. There are also layer 2 protocols like AVB and others, which I would avoid, as their "layer-2-ness" makes them more difficult to work with.
In any case, find a virtual sound card for one of those protocols, install it on both machines, route your source into the sending device, and then (on the other computer) loop the output of the virtual soundcard back to the real sound card (driving the speakers).
Answer: MS Windows provides network sharing of printers and hard drives, but I see no evidence that it supports sharing any other kinds of resources or ports or interfaces.  It is technically possible, but doesn't appear to be supported by the operating system.  That doesn't mean that there might be some way to implement it with layered applications.
Answer: Use Dante VIA. This will solve your problem. It's a product by Audinate that is designed for audio networking.
Answer: I've never heard of this being done. So I doubt it. But it would be down to the audio cards drivers to make it possible.


How many people have undergone carbon freezing in Star Wars?

Question: We all know the story of Han Solo being a guinea pig for the planned freezing of Luke Skywalker, but how often are people "stored" in this way?
Comment: Do you want only canon answers because the books from Del Ray have a number of other carbon frozen people.  I'm not sure if they are canon
Comment: Sure, as long as this doesn't turn into a list question. I just want to know how often it happens.
Comment: mostly duplicated here: http://scifi.stackexchange.com/questions/35841/what-was-the-point-of-testing-carbonite-freezing-technology-on-han-solo
Comment: @NKCampbell: This question is a little different than the one you've linked. Instead of asking why Han needed freezing, this is asking how many people have been frozen that we know of.
Comment: Right - that's why I said "mostly" instead of voting to close it :)
Answer: I wouldn't say people are "stored" this way very often. I'm sure there are instances of people being frozen in the Star Wars universe off-screen that we'll never know about because there are a lot of bad people out in the Star Wars universe. However, it has happened, in canon, prior to Han Solo being frozen.
In the Clone Wars episode The Citadel (season 3, episode 18), a team consisting of Obi-Wan Kenobi, Anakin Skywalker, Ahsoka Tano, and some clone troopers voluntarily underwent carbon freezing in order to infiltrate a planet that utilized lifeform scanners as a security precaution on incoming ships.

They were unfrozen by droids led by R2D2 when they arrived on the target planet.

By my count, this mission consists of about 8 people. Add Han Solo to the mix, and there's been 9 instances of carbon freezing people in on-screen canon.
Comment: @Paul: See [this answer](http://scifi.stackexchange.com/a/116833/19252).
Comment: @Paul - Basically, there's a big difference between knowing the process works and knowing a particular unit is capable of it.
Comment: If Anakin knew that carbonite freezing worked, having done it himself, why was Han considered a "guinea pig"?


What environment would goblins be best adapted for?

Question: Goblins in my setting are around four feet tall, with batlike ears, a keen sense of smell, and lithe, dexterous bodies. They are omnivores, eating slightly more meat than the average human, and their skin is tinted yellow-green or olive. What sort of environment would best suit them?
Comment: Race horse jockeys, child-actor stunt doubles, and pickpockets come to mind. In other words, mostly criminal environments.
Comment: Are they sapient? Do they have any other additional characteristics that differentiate them from baseline human?
Comment: Related to this question: https://worldbuilding.stackexchange.com/questions/102815/evolutionary-advantage-to-short-humanoids
Answer: A forest environment would be quite good, dense undergrowth blocks line of sight meaning that vision is less important than some other senses. Keen hearing and a good sense of smell would help,them detect prey and predators without seeing them.
Their lithe dexterous nature would help them climb like monkeys or lemurs and skin tone camouflage against some leaves.
Comment: Jungle or dense forest would be best, short stature is big disadvantage in grasslands but in dense woods it can work in your favor.
Comment: @John: Depends on grass height and leg-power-to-weight ratios. The goblins of the Wherethehellarewi tribe do quite nicely by hiding in the long grass and periodically jumping in the air to check for predators.
Comment: @John: I wrote that mostly for the tribe name. I agree with you. :-)
Comment: [Ixalan's Goblins](https://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=435314) fit this description.
Answer: I would assume that the goblins of your setting are sapient tool users. It means, essentially, that they could adapt to any environment, just as humans.
Most of the factors you describe - height, sense of smell, hearing, skin color - do not strike me as essential. What seems to be important are their dietary requirements. If they need more meat in their ration then human, it means they would develop animal husbandry over farming. Farming won't give them the essential nutrients, so it seems the Neolithic revolution won't happen to them - or it would look differently, if it did. So I would expect fishing villages, migratory hunting and herding communities and, possibly, mountain villages with transhumance herding.
It is hard to say anything else about them, because we don't know much about your world - what is the climate and continents, what is the population pressure of your goblins, are there other sapient races that compete for resources and land. If there are other races with farming and bigger population, you can expect your goblins to be pushed to less hospitable areas.
Comment: This doesn't really answer the question. humans eventually conquered the world but their are environments we are better adapted for.
Comment: @John I would say we need to wait for OP to clarify the question. The evolutionarily history of the species and their preferred environments, and the places the species with tool use and domesticated animals would prefer are two different and mostly unconnected questions. If OP wants the answer to the first question, I will take down my answer to avoid confusion.
Answer:
Lithe, dexterous, good hearing, short.  I would place them somewhere that vision is less important and hearing more.  I would place them someplace with many obstacles to straight movement where their dexterity can serve in good stead.  A forest or "jungle" would work.  If you have a D&D type underworld that would work.  A more exotic environment like the stone needles in this answer would work.  Tall grasslands might be a good option too, especially if goblins are nocturnal.
Goblins are social.  Small omnivores can eat a lot of carrion, like skunks or opossums.  There is not much need for them to be super quick or social.  If you want them quick then they could catch their food and semi-arboreal hunters in an environment with lots of obstacles could catch birds.   Sociality does not help with that kind of hunting.  Social omnivores could mean pack hunters.

So: goblins can be pack hunters living in a visually and spatially obstructed / dark environment.
Comment: jungle even gives a benefit to the coloration. It is one of the few environments where green  is good camouflage.
Answer: The homonin species that most closely resembles that was homo floresensis, which lived on a heavily-forested island.  The goblins might have started off looking like the real-world "hobbits."  They're that size and have large ears because they hide a lot; they might hunt fast animals by ambushing, or perhaps they're not at the top of the food chain.  Flores had giant komodo dragons.  The sense of smell might be useful for scavengers and the coloration would be good forest camouflage.
Answer: Your Goblins are quite similar to Goblins from Goblin Slayer (great anime with a rough start), in GS they tend to live in forests with nearby mountains and human settlements, they make burrows by digging or use old mines/forts.
Just from the fact that yours are green or yellow tinted you can place them in forests, prairies for the green ones because that would help them camouflage, and the yellow ones can be from more arid places (even though the best camouflage color for desert is pink).
Since you haven't said which era your world is I assume that is a medieval one, so I would place them nearby human settlements which they would approach to steal supplies/food, which would make villagers ask adventurers to slay them, which as an story hook for a MC works great specially if you make goblins quite easy to kill if they are lonely but big bastards if they are in a group on a cave.
Answer: To add to the other great ideas with a keen sense of smell they also could live in underground tunnels and come only up to hunt. So underground tunnels under a forest in the forest itself they got the advantage because of their colour and because they don't need to see well and they can hide in their tunnels there they have the advantage over any enemy that depends on sight.
Answer: I'd say large cave systems. Being short and dextrous makes it easier to move around small tunnels and tight entrances. As most animals who thrive underground, they rely mostly on their hearing and smell than their sight.
Light skin, greyish or greenish, also makes sense for environments with little or no light.
As for their diet, it really depends on what else is available in your world. But assuming they are somewhat smart, they could easily get outside (maybe at night, when hearing is enhanced and sight is less important) to hunt or fish.
In general, any biome that doesn't let you rely on sight (lots of obstacles, or lack of light) would work.


How do you add a cool down timer?

Question: I'm working on a blender game with a character who can use certain abilities. With some of these abilities, I'd like to know how to add a cool down timer (e.g. 2 seconds) to them. How do I do this?
Answer: I suggest a timeout implementation.
Use a timer property to let the BGE count the time for you (timer properties always count upwards).
I suggest to use states to toggle between "ready" and "blocked" status.

State "ready".
In this state the operation can be activated at any time.
When the operation gets activated, you switch the state to "Blocked" and set the (negative) timeout value.

State "blocked"
In this state the operation should not be available.
All you do is wait until the timeout happens. You do this by measuring if time gets positive. When it does you switch to state "ready".

Conclusion
There are other ways to implement timeout. This one is a pretty efficient one as there is not really much to do rather than waiting on the events to happen. By using states you clearly separate the logic of both states.
I hope it helps
Answer: There are a number of approaches that you might use. Here are a couple of big-picture ideas.
1) You might record the time (milliseconds) that the ability was last used, and then if the player attempts to use the ability again you test to see if the difference between the recorded time and the current time is large enough. This has the benefit of only needing to be calculated when needed. This method would make it slightly more difficult to show a live count-down to the player, though. you could record the time in a custom property that's associated with the character, or with the ability.
2) You might set the value of a variable or property to a large number when the ability is used, and then periodically update that value to decrease based on how much time has passed. Then when the counter reaches zero, your ability is available again. This has the benefit of being flexible. You can update more frequently if you need to, or less frequently if granularity isn't very important. You have a rough estimate of how much time is remaining and can easily drive other features with that value. This method is also easy to make based on something other than time. Anytime a particular event occurs (each button press, enemy hit, etc.), you subtract one from the value until it reaches zero. This is useful for other kinds of timers in addition to cooldown.
3) Lastly, you might set a property to "always" update a given value, using either of the first two methods. This will force Blender to calculate it every "tic." This gives the most real-time information, but it's one more calculation that has to be done before a tic can be finished, meaning that each tic will take longer.

How do you add a cool down timer?


How to find a mountain bike that can handle a heavier (250-260lbs) rider?

Question: I am a 44 year old man that is very heavy (250–260lbs(113-118kg)) and I am looking to buy my first mountain bike to do some riding on the weekend to burn off some of this fat I have.
Comment: Question:  Do you know you want a "mountain bike" -- a bike designed to go offroad -- or do you simply want a "mountain style" bike -- upright posture, flat handlebars, etc?  If the latter, then you should probably look for a "hybrid", and there are good options available starting around $400 new.
Comment: BTW, a decent quality hybrid bike should easily be able to handle your weight.  You might find the standard saddle a hair uncomfortable and swap if for a wider one, but otherwise it should work for you.  Just keep the tires well inflated.  (I weight 230+ and commonly ride with another 10-20 pounds of junk in my panniers -- this on a "touring" bike that is a bit more lightly built than a good hybrid.)
Comment: Please note that the [many](http://bicycles.stackexchange.com/a/31882/7044) near [duplicates](http://bicycles.stackexchange.com/q/6024/7044) of this [question](http://bicycles.stackexchange.com/q/28836/7044) have [additional](http://bicycles.stackexchange.com/q/14334/7044) information in the [answers](http://bicycles.stackexchange.com/q/9092/7044).
Comment: I weigh 275, and I have used a Trek 3900 for a few years with no problems
Comment: Steel frame and extra large frame to reduce seat post height?
Answer: 250-260 pounds isn't that heavy.
You may not need to worry about weight at all.
See if you can find the information from the manufacturer about weight limits for their bikes. For a mountain bike that you intend to use for what it was made for, you're probably within the weight limit the bike is designed for.
You may want to avoid the lightest weight stuff (carbon) unless you check the weight specs. But that's mostly stuff on the more expensive bikes.
Some of the parts that normally wear out will likely wear out faster for you than for somebody lighter, but that's no big deal.
If you plan to do tougher things with the bike than it was made for (jump a trail bike, for instance) you could run into problems. Stick with getting a bike that's intended for what you plan to do with the bike.
For instance:
1. Trek Bikes Weight Limits:

Rider weight limit of 275lb: Road bikes with drop type handlebar
  Triathlon, time trial or Speed Concept bicycle Cruisers with large 26"
  tires and swept-back handlebar, Bicycles that fold.
Rider weight limit of 300lbs: Hybrid bicycles with 700c wheels, tires
  larger than 28c, and flat handlebars City bicycles: hybrids with
  special equipment, cyclocross bicycles: with drop type handlebars,
  knobby 700c tires, and cantilever or disc brakes Mountain bikes of all
  types including: standard, race, cross-country, heavy-duty, trail,
  all-mountain, freeride, and jumping bikes of both the hardtail and
  full suspension variety.

2. Specialized Bike Warranty Policy (PDF) (weight info near the bottom):

Also, some bicycles and components are built to be lightweight, which means they may not be appropriate for riders who are approaching 250 pounds in weight (over 240 pounds, for example). Riders approaching 250 pounds in weight should not ride any bicycle equipped with Specialized-branded composite seat posts, handlebar stems, or handlebars.

In other words: avoid the carbon/composite seat posts, handlebar stems and handlebars and you'll be fine with this brand.
3. Cannondale 2010 User's manual (PDF) (Starting at page 52)

High-performance road: 275 pound rider
General Purpose Riding, Cross-country MTB, Marathon MTB, Hardtail MTB, All mountain, Gravity, Freeride, Downhill, Dirt Jump, Cyclocross, basically everything they make except high-performance road bikes: 300 pound rider, as long as you stick to the intended use. Limit on cargo goes from 5 pounds to 55 pounds
Comment: That shouldn't be a weight issue - more likely a cable tension or misadjustment issue. If you're not reckless (don't ride off curbs on your hybrid for example), pretty much anyone under 300 pounds should be fine on a non road racer bike. Most things have a lawyer margin so they dont get sued if things go wrong.
Comment: FYI, I do speak from some experience. I rode a cheap hardtrail Trek mountain bike for years when my weight was 250-260. Now I'm 240-245 and ride a Trek CX bike and a Surly touring bike. Really no weight-related problems with any of those, except the rear wheel on the old MTB starting to break spokes after probably 5000+ miles...
Comment: Just chipping in as a 350+ lb rider, you may run into minor problems with a Specialized bike.  I have a Crosstrail and everything is fine except for one issue.  I can't seem to get the derailers adjusted to shift the front gear from lowest gear.
Answer: Don't go full suspension - it at $1000 price point its a gimmick, and at your weight, you would need highend stuff for it to be adjustable enough to be useful. I am sure you can spend less, (I ride off-road with a guy who's 220lbs, hes really fit and all muscle, rides hard and fast. His sub $1000 bike stays in one piece), unless you are looking for serious off road use.
I would strongly recommend buying form your local bike shop rather than Kmart. They should be able to put you oto a bike that will meet you budget, fit you properly and give you advice. They will also be able to maintain it for you. If they can't put you on a bike within your budget look for one that has lots of kids bikes, they will understand the budget, and wont try to tell you that you need the lycra clothing to go with it.
Answer: I agree with the others: your weight is not that much of an issue for a decent quality well under $1k bike. I'm 175lbs now, but when I first started riding at 360lbs I rode a Specialized Big Hit Mountain bike. About $1,600 and overkill for the on-road riding I did.
I now use a simple Trek Hybrid, and love it.. no clunky clumsy mountain bike.. (unless of course you are using it off road..  I  never did and never intended to).
The bottom line is don't overthink it. Find the weight limits. Some kind person listed Trek's above.. and there are other brands as well.. and go for it.. Just move and watch the carbs and calories and the weight will fall off.
Answer: As someone who weighs in at 375lbs, I can tell you that a good build will hold up just fine.  I would stay away from box-store bikes (Walmart, K-Mart, etc) and shady bike shops, as they tend to cut corners in components and overall build quality.  Hit up your local bike shop and let them know your worries.  A good bike shop will probably have some great suggestions for you.
In my case, I prefer steel bikes (started on a Trek, then went to Surly).  I know that From my understanding, aluminum bikes are stronger, but I have a mental block against "lighter", so I stick with steel.  The only problem I have run into was wheel quality.  Once I went to hand-built wheels with quality components, I stopped having problems.  Right now I ride a Surly Ogre with 36 spoke wheels atop Surly New Disc hubs; they are pretty much bullet-proof.
Answer: I was a daily bike commuter in the 325lb range for almost two years. I rode both a restored '70s Raleigh Record Ace street bike and an Electra Townie 21D.
Lessons Learned:

Bike frames and seatposts are really, really tough. As long as you aren't boulder-hopping or crashing over pot-holes at speed, it's unlikely you'll break one, especially a new aluminum MTB, as they're way over-engineered (well, Electra's is, at any rate.)
The stock seatpost clamp on the new MTB was too weak to maintain seat height, and was replaced by a generic yet beefy aluminum component (ebay is a great source for these kind of components - also scored a "brake booster" which I used for mounting the front fender).
Suspension forks are useless. You'll be bouncing non-stop as you pedal. Go for fixed forks, or plan to swap out the suspension forks for an aftermarket fixed fork if you can't find a model you like. I did this on the Electra - had the added fun of swapping from a threaded to a threadless headset, as I was unable to find a threaded, suspension-corrected fork in the right size. The difference was night and day, especially on steep hill climbs and fast straightaways.
The plastic pedals or skinny "rat-trap" pedals that come stock are pretty weak, and I bent them easily. BMX platform pedals are cheap, indestructible and work well.
Vintage bearings are pretty weak - especially the bottom bracket, I went through more than a few re-packs - upgrade to quality modern BB cartridges and wheelsets. Modern MTB bearings are bulletproof for casual riding or commuting.
Invest in good wheels - not expensive ultra-light wheels, but quality rims and spokes. Hand-built is nice, but name-brand wheelsets from the factory and tuned by the bike shop proved plenty tough. The generic stock wheels on the vintage bike and the new MTB were both not up to the task, and needed constant truing, often mid-ride.
Invest in puncture-proof tires, and keep them inflated, check the pressure often. Heavier riders will pick up more glass shards, sharp rocks, tire wires, lost screws and can fragments, as the rubber presses down harder. Once I switched to Conti Gatorskins on the roadie and CST puncture-proof hybrid tires on the MTB, issues with constant flats pretty much went away so long as the tires were properly inflated.
Keep an eye on your crankset. The vintage bike's rings were nigh invulnerable, the MTB one started to warp and kick off chains after a year of heavy use. Go for sturdy rather than light, and from a reputable midrange component family if/when replacing. The freewheels are name-brand, down-market units - an IRD wide-range 5 cog on the roadie and a Shimano 7-speed mega-range on the MTB - and held up without a hiccup.
Keep an eye on your chain for stretch and wear, too - beefy guys are wicked strong for short bursts and can apply more torque than they mean to heading up hills or over obstacles. To be honest, cheap, generic chains hold up just as well as name-brand ones.
Likewise keep your derailleurs in tune - you can break cheap indexed shifters by trying to force a shift that isn't gonna happen. Big guys sometimes use force rather than finesse, because they can. I broke a trigger-shifter on the MTB this way - it was a flimsy, plastic OEM unit, but it was integrated with the brake lever. I replaced it with sturdy, mid-range name-brand components, separate levers and shifters that could hold up to over-eager mashing. It turned out to be cheaper than replacing the broken unit with an identical one.
Answer: You might look into something like the Kona Hoss, which I believe is no longer made but can probably be found used. Here are some reviews on MTBR.
The most critical thing to selecting a bike will be getting strong wheels, crankset, seat & post, pedals, and fork. These are the components that bear most of your weight. You can probably start with almost any mid-range mountain bike and just make a few changes:

Install a rigid fork. Unless you want to spend a lot of money, it will be hard to find a good fork that's going to hold up well to your weight.
Upgrade the wheels. Look for something marketed as a free-ride or all-mountain wheelset. This should be significantly stronger than the stock wheels on a lower end (<700) bike.
Buy some BMX style platform pedals. They're not too expensive and will be plenty strong.
Ride the thing and see how everything else holds up. If you bend the seatpost or have trouble with the bottom bracket and crankset, you can upgrade them as you go!

Bottom line: You don't need to spend $1000 plus, unless you want to. You can probably find a decent used bike on Craigslist for $200-300, and then budget another $200 for some simple upgrades. You should also invest in a nice pair of bike shorts. There are lots of non-spandex options that look just like regular street shorts. Once you start riding and losing weight you may find you want a different type of bike or something fancier...
Have fun.
Answer: Being 240 LBs and now being on my third bike I thought I would throw this in.

I destroyed a department store bike in 3 months of commuting on roads. It started failing after a month. Don't touch these unless bike security is a problem.
I replaced this with a $1000 MTB. Within a year the entry level shocks had gone even though I was only commuting. I would suggest if you are a heavy rider and you want shocks, you will want quality shocks. Its hard enough riding hills with a solid fork but its a lot harder with a failed fork.
After 12 months my rear wheel started breaking spokes. Such is life.
After 15 Months the aluminium frame broke at a join (chain stay and crank shell) and I entered the warranty time hole. If you're a heavy rider and want an aluminium or Carbon bike you need a quality frame, the manufacturing of these materials has very little room for error.

Now I ride a Surly disk trucker, it's been 7 months and all is well. I don't commute anymore but do 25 mile morning rides with plenty of hills 3 times a week. Fingers crossed the Surly will hold up it's a nice ride.
Comment: Cheap double suspension bikes are a bad idea overall.
Answer: I'm a heavier rider (250-260) and the first thing I do when I purchase a new mounain bike is invest a good chunk of change into better front and rear rims.  In this day and age, the stock rims are pretty weak and tend to break first in the spokes.  It's also not uncommon to have a bent rim when going off a curb.  I should also note that I punish my bikes when I'm out doing distance rides (20 miles or greater) or offroad.  I went through three rims one time within a month of buying a bike in the past.
Answer: I fit in to that weight category and I ride a Trek superfly 100Al dual suspension bike. I do ride it hard and even being the biggest bloke in the group that I ride with, I can out ride most of the lighter blokes. I ride the bike hard and unfortunately I do regularly break things. I have re-spoked the rear wheel with heavy duty spokes after breaking too many spokes, but recently I broke the rim so I now have a much stronger new wheel. I also wear out the rear suspension bushes approx. every 8-12 months. The running gear (chain, chain rings and cassette) also gets replaced every 6-8months. But having said this I ride about 8-10000km a year and most of that off road and often giving it a hard time (do you see this common point I keep bringing up).
So what I am trying to say is, get yourself good equipment but be prepared to do extra maintenance especially if you give it a hard time. But the main thing is get out there and enjoy it and don't give up. About 4years ago I was just over 370lbs and now I am around the 250lbs (I hope to drop a few more as riding has helped heaps)
Answer: I am two metres tall, 124 kgs (272 lbs) and ride a collection of road and mountain bikes. I am aggressive and fast and have never worried about the bike coping. I ride cobblestones and speed over driveway lips, tram and rail tracks and the like. My current fave bike is a cheap factory excess frame I found on eBay and equipped with a decade old collection of parts of a frame I did manage to break after 10 years of hard riding. .. You might need to get decent (that does not mean expensive) wheels. But I would likely replace the factory tires for something with a lower profile, slimmer (yes, slimmer) and faster, if you are mostly riding on pavement. Or relax and just wait until the wheels need replacing. They will not collapse into dust. The rims will get flattened, spokes break... You will live.
Answer: I own two Treks, an X Caliber (great hardtail that starts around $650 range) and a full suspension Trek Remedy 29 9 (phenomenal bike, but is 5gs) I weighed 321lbs when I started riding again, and now am about 255lbs. Both bikes have had no problems whatsoever with my weight. The Treks have a 300lb weight limit listed, but I believe that is well under what they can really handle. Plus, they just make great bikes. I do think the 29 wheels are better for riders as well, but not posite on that.
Answer: I'm in the same kind of weight range, and also usually carry a fair bit of stuff around (books, laptop for daily commuting, shopping, occasionally a 25kg sack of concrete for some garden work..., two heavy locks), so I'd say 130 or 140kg is a fairly normal load for my bike.
Much of it depends of course on what kind of cycling you do. I don't do sports-type cycling, it's all utility, in total about 50-80 km per week. Roads here are full of potholes, cracks and craters, it is also not very flat, so downhills I can go well above 30km/h (20mph). So I think it gets a fair bit of stress, although not as extreme as offroad/mountain biking or long club rides etc.
My current bike is a commuter hybrid, in around £600 range (not including extras like lights, rack, mudguards etc), aluminium MTB frame. Had it for more than three years now and no sign of any trouble. The bike I had before was decades old, no real trouble either.
The advice I found was mainly get solid wheels with wide tyres (mine are 44-622); wheels designed for MTB should handle much heavier riders on normal usage. You don't have to worry much about the frame and other components. Keep the tyre pressure up, and while you check pressure and tyre damage, also have a look at the wheel (broken spokes, cracks in the rim, is the wheel true?).
I can second the advice not to get full suspension. I sometimes used hire bikes with full suspension and that felt more like riding a horse than a bike. But I do have front fork suspension and that works just fine, in fact I think it is quite beneficial when I hit one of our potholes. I also installed a seatpost with suspension, although I'm not sure this does much at all.
Answer: I'm a big boned and tall guy, currently at 270lbs, which is about 30 pounds more than I want to weigh. I have an older Cannondale Jekyll with full suspension. I had heavier springs installed in the front forks and at the rear is a Fox air shock that has held up fine so far. I'm pretty sure I surpass the bike's weight capacity and it concerns me, but the guy at the bike shop said don't worry about it. I mainly ride it on the street, jumping off curbs and hitting lots of ruts and bumps and so far, no problems.
Answer: As many others have said, you're not really in the "extreme" weight range. There are many quality bikes that will do just fine.
That said there are three things that are worthy of your attention:

Your wheels – if the spokes are not tensioned evenly and are not tight enough the wheel is likely to be unstable and you're also more likely to break spokes. A new bike from a reputable shop should have the wheels properly trued and tensioned – and the wheels should be covered by the warranty. If the bike is used, it wouldn't be a bad idea to have the wheels checked.
Your seat – having your seat properly adjusted will go a long way towards making riding a pleasant experience, but it is also possible that the seat that comes with the bike is the wrong shape for you. If you're buying the bike locally that would be something to bring up with the sales person. They may be able to steer you to a better seat from the beginning. In any case it seems that many shops sell parts like seats and stems with a reasonable return policy. It takes time to know if the part is right and they are willing to exchange them if they don't fit right. Just keep the packaging and receipts and try to be nice to them.
Similarly with the stem – it is fashionable on many bikes to have the bars too low. If you're buying a bike new see if you can get the steering tube left long until you know where you want the bars. You can also get extensions to help get the bars up to a more comfortable position.

The bottom line is that it should be possible to make your bike quite comfortable. If it isn't the problem is much more likely the fit of the bike than you.
Answer: I ring in at about 280 lbs (125 kgs).  I ride 100 kms/week mostly hard pack, gravel, sand, sand over hard pack.  Lost of bumps and pot holes but few roots or large rocks.  My riding style is fast and hard.  I have an entry level Cannondale with an XXL frame which is sweet as honey. I break spokes on a regular basis.  I just threw in the towel on the OEM wheel and got a new wheel.  The bike experts I have spoken with say that an $800-1000 bike should have sturdy wheels for the large lad.
Comment: Welcome to [bicycles.se]  @Kelly. I think I can see how you answer the question, but your readers shouldn't have to work that hard. Please edit your post so that it clearly answers the question. Cheers


How do I tweet a thread of tweets at someone?

Question: If I want to tweet something to someone on Twitter, but what I need to say will take up more than one tweet, how do I tweet it at the person in a way where the tweets will be nicely threaded when the person clicks on the first one, and where my later tweets will not show up on the main "Tweets" section of my profile page?
Answer: Here is the solution to your need... when you compose your threaded tweets, begin each tweet in the thread with the @username of the person you wish to answer:

As you can see in the image below, when you post your thread, Twitter will only show the @username on the first tweet but NOT on the rest of the threaded tweets:

NON of the threaded tweets will appear on the "Tweets" section of your wall, nevertheless, they will be listed in the "Tweets & replies" section.
Comment: Thank you for the suggestion but I'm really looking for something within the Twitter app.  If I'm tweeting at someone who doesn't know me, they may not want to take the extra step of clicking on the link to see what I have to say.  Also, to clarify: by "Tweets section" I was referring to the main list of tweets, not the "Tweets & Replies" section.
Comment: Thank you for clarifying your question. I have reedited my answer above with a solution to your need...
Comment: Did you try the method i described in the re-edited answer above? I believe it should provide an adequate solution to your need...
Comment: When you first said you'd updated it I didn't see the updated version.  I just checked and I agree that your new solution seems to be the right answer to my question.  The web UI for Twitter just totally changed for me at the moment I was testing this, though, so that has me a little confused, because now when I click on "Show this thread", I don't see all tweets of a thread.  But I guess that's a separate issue.


How does Tor pass my traffic around and should I be worried about malicious relay operators?

Question: I am not sure how does Tor work, how safe is it as I heard that some relays are ran by bad people or government agencies.
Comment: Hm. I wonder if this should be best broken into two different questions? I guess the answers are sort of related, but I think we want better answers for each of them independently.
Comment: I agree, should've done that from the beginning..
Comment: Closing as too broad and probably either of those questions is also too broad or not answerable: how does Tor work requires a very complex answer and "should I be worried" doesn't really seem to have a specific answer.
Answer:
how does Tor work

When you connect to the Tor network a Tor circuit is formed which consists of three relays (entry node, middle node and an exit node), Tor encrypts your traffic and passes it through its circuit then when your traffic reaches its destination node (outside of the Tor network) and the encryption is lifted off.

how safe is it as I heard that some relays are ran by bad people or government agencies.

Will explain that through an example:
Lets say you visit https://twitter.com/ your traffic enters the Tor network then exits at Twitter's servers and the effects are:

Twitter cannot know your real IP address or physical location.
Your internet service provider will not know that you are using
Twitter, because to them you are communicating with the entry node
only.
Your traffic within the Tor network is encrypted multiple times in order to
prevent any eavesdropping from relay operators. But when your traffic
leaves the Tor network and reaches its destination (Twitter's
servers) the encryption must be lifted off so that your request can
be understood by Twitter, this is why you should always use HTTPS,
because HTTPS will encrypt your traffic even after leaving Tor's
exit node protecting you from a bad exit that may try to read your
data.

EDIT:
The EFF made a nice interactive web page that illustrates the usefulness of using Tor and HTTPS together.
Comment: It might also be worth linking to https://www.eff.org/pages/tor-and-https. It's a great interactive visualisation of Tor and what sort of attacks it protects against.
Comment: Thanks Philip I just added it, I am also using it in #5991
Answer: In general everyone can operate a relay. Those can be either good or bad guys. Bad guys can do everything. This ranges from passive listening to injecting malicious content. When the main Tor people learn about those bad things they can give the Tor relay a special mark (Bad Exit flag). In this case no other client will use those relays.


Does buying whey increase demand for dairy?

Question: Is whey (the liquid remaining after milk has been curdled and strained) a byproduct that does not increase demand for dairy? Is whey powder just a handy use for a food product that would otherwise go to waste, or is it a thing like cheese that creates demand on dairy to make?
Comment: i would say it at least helps "them" to make more money from the animals, making it more profitable
Answer: No it's a waste product that's been repurposed. New Zealand has one of the largest dairy industries and only a fraction of the whey produced is used for human consumption (such as cheese and protein supplements) 1. The vast majority of whey is used for fertiliser which would otherwise go to waste. The majority of milk produced is used to make milk and milk powder. These are more profitable than butter or cheese but cannot be shipped as far (statistics from MAFF Japan, where butter shortages frequently occur and tax incentives are being used to counter this). This would still be the case, whether or not there were demand for whey. It is arguably better that whey is reused than discarded as it was once a significant source of environmental pollution until it began to be used 2.

N.W. Sneddon, N. Lopez-Villalobos, R.E. Hickson, S.R. Davis, U. Geary, D.J. Garrick and L. Shalloo
Irish Journal of Agricultural and Food Research
Vol. 55, No. 2 (2016) Dairy product production and lactose demand in New Zealand and Ireland under different simulated milk product–processing portfolios pp. 126-135
S. S. MARWAHA J. F. KENNEDY. International Journal of Food Science & TechnologyVolume 23, Issue 4 (1988) Whey—pollution problem and potential utilization
Answer: Yes, it's a waste product that's been repurposed.  Repurposed into a product.
So this may sound like a trick answer, but I think it depends what you mean by demand.
Just because it doesn't make people demand "more dairy please", doesn't mean it doesn't achieve the same end result for the industry.
The bottom line for the dairy industry is money in the bank, if people buying more cheese will do it, fine.  If shoehorning dairy as a hidden ingredient in a product there is demand for will demonstrate indirect demand for dairy, that's also fine.
Likewise, if they make money from whey (or otherwise benefit in some reciprocal arrangement or avoiding disposal costs/fines), it's good for the industry, even if it doesn't technically increase consumer demand.
So, it depends if you are concerned with the fact of demand or the outcome of demand.  I think it's a drop in the ocean... and better than it being dropped in the ocean.


Find all the continuous functions such that $\int_{-1}^{1}f(x)x^ndx=0$.

Question: Find all the continuous functions on $[-1,1]$ such that $\int_{-1}^{1}f(x)x^ndx=0$ fof all the even integers $n$.
Clearly, if $f$ is an odd function, then it satisfies this condition. What else?
Comment: Can you find a special case?
Comment: **Follow-up exercise**: Drop the continuity requirement and replace it with $f \in L_1([-1,1])$. Show that the answer doesn't change except for the qualifier that it only hold almost everywhere.
Answer: You observed that every odd continuous function $f$ satisfies all of these equations. Try to prove the converse also: If $f$ is a solution, then it is odd.
Hint: Every function $f$ can be split into its even and odd parts. It therefore suffices to prove the following: If $f$ is even and solves your equations, then it is identically equal to zero. Think about approximation by polynomials. Show that an even function $f\in C([-1,1])$ can be uniformly approximated by even polynomials. There are multiple ways of doing this.
Answer: Since any $f(x)$ can be divided into a sum of odd and even functions, say $f(x) = g(h) + h(x)$, where $g(x)$ is odd and $h(x)$ is even, we may concentrate on asking whether or not even functions such that:
$$\int_{-1}^{1}{h(x)x^ndx}=0$$
exist. Moreover if such a function does exist, it is also true that by construction for every even polynomial $P(x)$:
$$\int_{-1}^{1}{h(x)P(x)dx}=0$$
We construct $P_m$, the $m$-polynomial expansion of:
$$\frac{\sin(m (x-\alpha))}{m(x-\alpha)} + \frac{\sin(m (x+\alpha))}{m(x+\alpha)}$$
At the limit $m\rightarrow\infty$:
$$\lim_{m\rightarrow\infty}\int_{-1}^{1}{h(x)P_m(x)dx}=2h(\alpha)$$
Since we can construct such a series for each $\alpha$, the function $h(x)$ must be arbitrarily small at each point, hence showing that no such even non-zero functions exist and that only odd functions fulfill the requirement.
Comment: I am probably misreading, but you seem to be assuming $a_m \geq 0$.
Comment: Not all continuous functions are analytic. Some are not even first differentiable.
Comment: @BabyDragon - I think it should be OK now.
Comment: @cardinal - you were right, the proof now does not assume a series representation.
Answer: Rewrite the integral as
$$\int_0^1 [f(x)+f(-x)]x^n dx = 0,$$
which holds for all even $n$, and do a change of variables $y=x^2$ so that for all $m$, even or odd, we have
$$ \int_0^1 \left[\frac{f(\sqrt{y})+f(-\sqrt{y})}{2 \sqrt{y}}\right] y^{m} dy = 0. $$
By the Stone Weierstrass Theorem, polynomials are uniformly dense in $C([0,1])$, and therefore, if the above is satisfied, we must have
$$\frac{f(\sqrt{y})+f(-\sqrt{y})}{2 \sqrt{y}}=0$$
provided it is in $C([0,1])$. [EDIT: I just realized the singularity can be a problem for continuity--so perhaps jump to the density of polynomials in $L^1([0,1])$.] Substituting $x=\sqrt{y}$ and doing algebra, it follows $f$ is an odd function.


Can a third type of electrical charge exist?

Question: Upon reading my book on physics, it mentions that there are only two discovered types of electric charges. I wonder if there could be a third type of elusive charge, and what type of effects could it have upon matter or similarly?
Comment: @BMS : formally there is only one type of charge. The sign of charge isn't important.
Comment: I hope that answers don't only discuss how current theories are only consistent with two types of charges, but also how our theories *would need to change* in order to allow a third type of charge.
Comment: Comment to the question (v1): It seems that the question should only be answered by a brief _No, standard E&M has only an one-dimensional real axis of possible electric charges (which includes positive and negative electric charges and ignoring magnetic monopoles)._ Any attempt to justify standard E&M will likely fall short of an actual proof of uniqueness. Any discourse into non-standard E&M is likely _off-topic_ or _too broad:_ For starters, there are Yang-Mills-type theories.
Comment: @Qmechanic I am trying to understand your comment: given objects $A,B,C$. if $A$ attract $B$, and $B$ attract $C$, and if we make up a toy model about "two-dimensional real axises of possible electric charges", then, under that model, $A$ does not have to repel $C$?
Answer: No, there are only positive and negative charges. Or, more carefully stated, if there is a another type of charge, then electromagnetism is not what we are currently thinking it is.1
Electromagnetism is a $\mathrm{U}(1)$-gauge theory, which relies on introducing the covariant derivative
$$ D_\mu = \partial_\mu - \frac{e}{\hbar}A_\mu$$
acting upon matter fields in representations of the $\mathrm{U}(1)$ labeled by $e$, where $A_\mu$ corresponds to the four-vector potential of electrodynamics. There is no possibility for matter fields to gain any other kind of charge here, since all representations of the circle group decompose into these one-dimensional representations of charge $e$, so charge is simply an integer $e \in \mathbb{Z}$. (The $\mathbb{Z}$ and not $\mathbb{R}$ come from the fact that $\mathrm{U}(1)$ is compact)
If there were other charges, we would need another (non-abelian, Lie) gauge group $G$ with some $\mathrm{Lie}(G)$-valued "potential" $A$ and a covariant derivative looking like
$$ D_\mu = \partial_\mu - \frac{g}{\hbar}\rho(A_\mu)$$
where now $\rho$ is some (irreducible) representation of $G$ and the $g \in \mathbb{R}$ is called the coupling constant. The charges lie within the representations and are usually thought of as the (root of the) eigenvalue of the quadratic Casimir operator in that representation.
Since $\mathrm{U}(1)$ has only one generator, its Casimir is simply that generator (squared), and we reconcile this with the above has observing that the representations of the circle group are indeed given by sending its generator to its $e$-multiple as per
$$ \rho_e : \mathfrak{u}(1) \to \mathrm{GL}(\mathbb{R}) \cong \mathbb{R}, \mathrm{i} \mapsto e\mathrm{i} \text{ with } e \in \mathbb{Z} $$
Note on QCD (where the idea of "other electric charges" probably came from): The specific occurence of things like "colors" is not quite compatible with this language, as one usually identifies each dimension of a non-trivial representation with a color, but since irreducible representations have not subrepresentations, a gauge transformation will change the colors around (it won't change the quadratic Casimirs, which is why they are the proper generalization of charge, and not the colors). Nevertheless, also under this idea of charge, $\mathrm{U}(1)$ theories have only positive/negative charges, as their irreps are one-dimensional.

1 Looking at the real world, we know that electromagnetism must be a $\mathrm{U}(1)$ theory, since photon do not interact easily - they do not couple to one another on the tree-level of the quantum theory, and thus two laser beams do not significantly scatter off each other. In non-Abelian theories, the force carriers (gluons) do interact on the tree-level, and would thus deliver a wholly different force, more like the strong force, not long-range, and gluon beams would either not exist, or be very weird things. (though the details would be probably tricky for arbitrary $G$, granted, and could produced other weirdness as well)
Comment: @PhotonicBoom: Choose $e = 1$ to be the quark charge, nothing here says that $e = 1$ must be the electron charge. There's also the possibility to use a different $g$ for different particles, since, comparing with the more general formula for the cov. derivative, I set $g = 1$ for the EM constant. Essentially, there's nothing *fractional* about the quark charge except our predisposition to take the electron charge as fundamental charge unit (which has no theoretical basis compared to the quark charge)
Comment: If $e$ is necessarily an integer, then how do the fractional quark charges come about?
Answer: In the Standard Model, electric charge $Q$ is actually part weak hypercharge $Y_W$ and part weak isospin $T_3$
$$Q = T_3 + \frac{Y_W}{2}$$
which can be either positive, zero (electrically neutral), or negative.
In this framework, that's it.
If, in fact, there is another type of electric charge (and its associated anti-charge), I believe it would be the case that the there would need to be three types of photons which would themselves be electrically charged and, thus, interact with each other.
This is in analogy with weak isospin where the three weak 'photons' ($W^+, W^0, W^-$) are isospin charged.
This would, of course change everything.  But, we see only one type of photon and it is electrically neutral.
Comment: @HDE226868, the $Z^0$ is a certain mixture of the $W^0$ and $B^0$ bosons.  $Z^0 = \cos (\theta_W) W^0 - \sin (\theta_W) B^0$
Comment: @BMS, I'll work on a simple explanation for why an additional electric charge variety (and associated anti-charge) would imply three charged photons later but it's time to feed the horses.
Comment: Is there a simple way to understand how three types of "charge" require three force-mediating bosons?
Comment: Out of curiosity, is the $W^0$ the same as the $Z^0$ boson?
Comment: @BMS, three types of charge, e.g., red, green, blue (plus the anti-charges), requires 8 gauge bosons.  Two types of charge, e.g., up, down (plus the anti-charges) requires 3 gauge bosons.
Answer: Mathematically, electric charge current 4-vector conservation refers to the invariance of theory under U(1) transformations, so there aren't different types of electric charge (like in SU(n) theories) excepting the usual plus-minus.
Moreover, the fact of conservation of physical quantity means that corresponding operator commutes with hamiltonian which is constructed from fields operator. It's not hard to show that particle must have charge which is opposite to the antiparticle one.
Answer: Empirically, that is in Nature, we find only two electrical charges and this is taken into account by our best theory of electromagnetism: QED
This is a quantised theory of a gauge theory with gauge group $U(1)$. There is only one such gauge group here and this is the $U(1)$ in the standard model.
But what happens if there are more than one gauge groups? Then arguably we have more electrical charges. This naturally occurs in String theory, which is a speculative theory of quantum gravity that originally arose from the dual resonance models of the strong force. It is equivalent to super-gravity in certain low energy limits. Melanie Becker writes:

The $N=8$ supergravity theory in five dimensions contains a number of 1-form and 2-form gauge fiekds. However, by duality transformations the 2-forms can be replaced by 1-forms. Once this is done, the resulting theory contains 27 $U(1)$ gauge fields. Furthermore, the theory has a non-compact $E_6,6$ global U-duality symmetry. The 27 U(1) s belong to the fundamental 27 representation of this group.
Therefore a charged black hole in this theory can carry up to 27 different types of electrical charges. Some of these electrical charges can be realised by wrapping branes and Kaluza-Klien excitations.
Answer: Short and sweet: maybe, but so far, we haven't yet encountered a single problem whose explanation could be enhanced and/or improved by introducing a third type of electric charge into the existing theory of these phenomena. Science does not tend to complicate the working theories for no actual benefit.


Refrigerator Fruit/Vegetable Bins

Question: Is there anything that makes the bins in the fridge particularly good (or bad) for storing fruits and vegetables. Previous refrigerators had a moisture control slide that altered humidity in the bins. My new fridge does not have this. I would rather store bread, meat and cheese in the bins and have my fruits and vegetables accessible on the shelves. Any reason not to do this?
Answer: You can store whatever you want in these bins - I regularly use one of mine to store bottled drinks.
However, depending where the cold air outlet is in your fridge, placing relatively fragile items such as fruits and vegetables on the shelves could cause them to freeze or form ice crystals internally, damaging the item.
Things like bags of apples or oranges tend to take up a lot of shelf space, so a bin helps contain them a bit by forcing them to stack vertically more-so than a flat shelf would.
So, pay attention to where the air vent is and your fridge overall temperature, as well as what's next to the items - otherwise it's OK to store fruits and vegetables on the shelf.
Answer: The bins are actually called crisping or humidity drawers, so they do help with things like lettuces, celery and carrots.  They also control the gases the produce emits that can affect spoilage and over-ripening.  The use of two drawers is to keep fruit in one, and vegetables in another.  Their gases don't usually mix well and can cause spoilage.  Also, the drawers work better when full, so stock them up.
Storing produce on shelves for quick use should be fine, but in excess their gases can spread and affect other food.

Refrigerator Fruit/Vegetable Bins


When has a pilot legally accepted an ATC clearance or instruction?

Question: At what point is a pilot considered to have accepted an clearance or instruction? Upon simple acknowledgement (e.g., Roger or Wilco), any readback, correct readback, or something else?
Comment: In what context? IFR, takeoff, landing, Class B, LAHSO? And is there an importance to when it is legally accepted? The language I can think of is "obtained" in 91.123, not accepted, although accepted is used in LAHSO.
Comment: There is no such thing as "legally accepted". FAA regulations are REGULATIONS, not laws. The issuer will assume the pilot has "accepted" a clearance as soon as any acknowledgement is given.
Answer: I would try to not over complicate this issue.  There are three conditions a clearance/instruction can have:

Transmitted/Received
Accepted
Rejected

If ATC provides a clearance/instruction, but has not yet received a response, the clearance/instruction has not been accepted or rejected.
If the pilot acknowledges the clearance/instruction with a read-back or affirmation of understanding, then it is accepted.
If the pilot responds with the term "unable" to any element of the clearance/instruction, then the entire clearance/instruction set is rejected, which may prompt ATC to inquire as to why the clearance/instruction is being rejected or to provide a different clearance/instruction.
Per 91.3 the pilot-in-command reserves the right to act as the final authority as to the operation of the aircraft, but once a clearance/instruction is accepted, it is an indication that the pilot-in-command is agreeing, as the authority of operation, to operate by that clearance/instruction until released from it or forced to deviate due to an emergency or TCAS alert.
One note for safety: to be clear, one cannot simply reject one element of a clearance/instruction without rejecting the entire clearance/instruction.  For example, if ATC issues a turn and a climb, but the pilot's aircraft cannot or may not climb higher for whatever reason, the pilot should not read back the new heading and say, "unable climb," and then turn to the heading and wait for more instructions.  What if the climb is to avoid obstructions that exist on the new heading?
Comment: A clearance doesn't need to be accepted. It's a clearance, not an instruction. You are _cleared_ to do something, not required to do so.
Comment: A clearance can be refused based on parameters with which it might be issued.  Even instructions aren't required to be accepted and that is covered in another answer. Either one may be declined if necessary.
Comment: For example: a LAHSO clearance is a clearance, and by acknowledging it, you have accepted it.  If you can't land and hold short, you should reply to the controller, "unable" rather than replying, "Runway ##, cleared to land and hold short of runway XX."
Answer: This isn't a very satisfying answer, but as far as I can tell (after a lot of searching) there's no formal definition.
A lot of discussions about this start from 14 CFR 61.3:

No person may act as pilot in command of a civil aircraft under IFR or
  in weather conditions less than the minimums prescribed for VFR flight
  unless that person holds [an instrument rating and is current]

If that's what you were thinking about, the universal consensus on pilot forums is that by reading back an IFR clearance you're accepting it, and from that moment the flight is operating under IFR. However, there seems to be no explicit regulation or statement from the FAA to confirm it.
In fact, I couldn't find a definition (P/CG, 14 CFR 1.1 etc.) or FAA legal interpretation of what "accepting" a clearance of any kind actually means. The AIM and the ATC orders both refer to "acknowledging" clearances, e.g. in the ATC Orders (section 2-4-3):

pilots may acknowledge clearances, control instructions, or other
  information by using "Wilco," "Roger," "Affirmative," or other words
  or remarks with their aircraft identification.

And the AIM mentions some scenarios where a readback - as opposed to an acknowledgement - is required, e.g. this from section 4-4-7:

Pilots of airborne aircraft should read back those parts of ATC
  clearances and instructions containing altitude assignments, vectors,
  or runway assignments as a means of mutual verification.

But practically speaking, when ATC issues a clearance or instruction there are only three basic options:

The pilot reads back the clearance correctly (or ATC asks again until he gets it right)
The pilot acknowledges without a readback (and ATC accepts that, or asks for a readback)
The pilot says "unable" or asks for a different clearance

In case 1, it seems reasonable that the correct readback is the acceptance, because the pilot didn't decline the clearance or ask for a different one. In case 2, the acknowledgement is the acceptance for the same reason (I can't think of a good example offhand; see this question). In case 3, the pilot is declining the clearance anyway.
Personally, I think there's no formal definition  because it just isn't necessary. It seems obvious that by reading something back or saying "roger" you're agreeing to follow ATC's instructions, and I think it would be very difficult to argue differently.


Is it valid to offer salat ul tasbeeh after jummah prayer?

Question: After performing jummah pray I uses to offer salat ul tasbeeh pray, but my grandma said to perform salat ul tasbeeh before jummah. So I just want to ask is it valid to offer salat ul tasbeeh after jummah prayer?
Answer: This prayer is considered a nafl and has no specific timing -as in the hadith quoting it there was no mentioning of a special time-. So basically you could perform it at any time of the day or night unless it is a time one shouldn't pray (non obligatory prayers) at.
Note that the word jumua'h in the hadith (which soundness is highly questionable) refers to week (not the day of jumu'ah/friday necessarily, as Arabs used to refer to the week as "jumu'ah"), so the hadith says if it's possible to pray it once a day do so, if you are able to perform it once a week do so, if you are able to perform it once a month do so, if you are able to perform it once a year do so and if not perform it at least once in lifetime. This hadith explains how this prayer should be done.
Also note that the hadith about this prayer is considered as da'if by most scholars or even fabricated by the hanbali school of fiqh and therefore they reject it:
See for example islamqa #14320  and #145112, but among the salafi scholars al-Albani has considered it as hassan.
Also relevant Must Salatul Tasbih be performed at least once in a lifetime?


Metal crashing/friction sound while starting RE 350 classic

Question: I have bought my Royal Enfield 350 Classic bike 3 month back. Frequently I am hearing heavy metal crashing/friction sound when I start the bike. Sound is bit annoying. I am not even able to explain this problem in service centres, since it can not be regenerated. It happens randomly. I also suspect there is something wrong with engine. Has anyone faced this problem?
Comment: Can you record it and post it to YouTube and update your question with the link?   That could be very helpful.  Welcome to the site!   Cheers.
Comment: yes same issue i faced and told service centre guy, he replaced sprag clutch but same issue started after few month,
Answer: I have the same problem with my classic 350. It is due to starter sprag bearing wear out. Replace it and it will be solved
Answer: My best bet would be you have a broken sprag clutch. Have it checked and let us know. :)
Comment: YES. Exactly what I was going to suggest (though I could not remember that name for it). Pavunkumar: it is sometimes called a *freewheel starter clutch*. [Here is a gif](https://thumbs.gfycat.com/DetailedEnchantedIndianskimmer-size_restricted.gif) of one working. When starter motor starts turning, the centrifugal (?) force throws the little sprags outwards. The sprags grab the inside of the flywheel, turning it. Once the engine starts and starter motor stops, there is a spring which pulls the sprags back down so they do not stay in contact with the freewheel.
Comment: I had it break on my '97 BMW F650. It sounded like someone was shaking a metal box of screws when I started the bike. Sounded quite horrible. It gradually got worse over 2-3 weeks, and eventually I was not able to start the bike. Until you determine whether or not this is the problem, I recommend *only kick starting the bike*.
Answer: It could be a few things, from valve gear noise to piston slap to gearbox rattle, etc. Either way, you should get someone who knows engines to check it out for you, to either repair it or at least check that further damage is not being done.
Answer: For a new bike, below 10K trip, Sprag clutch should not be at fault.
However you may confirm it your self by removing the Left Hand Side engine casing. Relax its easy. You will need an 8mm T for casing and other sizes to remove foot paddle. A hell lot of oil will drain, so you may incline the bike to the opposite side, fully. A lot of debris inside the casing will tell you what the issue is. You remove the Sprag clutch bearing (one way bearing) and use Kickstart old school type. If the self assembly isn't too much worn out, the insude bearing will cost 2K original and 300 aftermarket. Complete assembly 4700 original and 2K to 3K aftermarket.


Why am I not seeing any new Facebook posts, even though my friends have been posting?

Question: I haven't been seeing any Facebook posts for the last few days and I know my friends have been posting. What should I do?
Answer: I think you have made some changes in your news feed. If you did not do anything then please try to login to your account from another system and see if you face the same problem. Try to clear the cache of your current browser or use another browser or check with other browser and see if it solves your problem.
If not, click on down arrow 'v' at the top right of your profile and set News Feed Preferences.
From the left hand side under Favorites you can change your News Feed. It has two options Top Stories and Most Recent. Choose Most Recent and refresh the page. Check if you are able to see the updates of your friends on your feed.
Answer: Facebook does have it own way of sorting post. It will display post that are most interacted with (by likes/comment/share) and show it to more "friend". It is the same with all the content a page you follow post. you won't see all of it.
If you want to be sure to see all the post someone post you can put the in your "Close friend" group so you will be notify at every post.
Answer: Delete FB account. It's great! Really I did.

You could be blocked. Blocking is secret as to not hurt anyones
  feelings, but you don't get to see updates. Only FB can see them and
  see their secrets, but not the blockees.


What to do before asking a minecraft-commands question?

Question: Want to ask a question in minecraft-commands? Don't know how to summon an entity or give a player an item? Read this guide first to make sure it isn't already covered here, or in one of the linked wikis or questions.
Comment: I wasn't really sure where to put this, so I put it in Meta. If this could be linked on the intro page, or maybe as a resource in the help section that would probably help a lot of people in finding it.
Answer: The first thing you should do before asking a question is read this guide to Minecraft Commands, to make sure that you know the basics.
The second thing to do is to make sure to search Arqade to see if anyone has already asked your question. If you still don't know the answer, then ask the question.

How to ask your question
A good minecraft-commands question includes:

A descriptive title
e.g. "How do I disable fire using commands?" instead of "Minecraft command problem"

A sentence or two explaining the context of your question
e.g. Are you creating a data pack, an adventure map, a command block creation...? Letting us know why you're attempting something makes it easier for us to suggest alternatives.
Another good habit is to mention the platform and version number in your question, e.g., Java Minecraft 1.14.3 or Bedrock Minecraft 1.12.

What your problem is or where you're stuck
Show where you're up to, including commands that may be broken and/or specific things that an answer must accomplish to be useful to you.

What you've tried so far
Including, but not limited to: commands, function files, data pack folder structure, command block settings, error messages, screenshots and really anything that can help us understand your question better.

FAQ
Please add to this list if you know of questions that are asked frequently.
Java Edition:

What are the basics of commands in Minecraft Java Edition?
How to color item names?
How to use /data modify?
Where to find vanilla loot tables
How to fix 'unbalanced brackets' errors in NBT
How to fix 'Invalid JSON' errors
How to test for a player at specific coordinates?

Bedrock Edition:

NBT in Minecraft pocket edition (everything in {} curly brackets)
How to fix 'Invalid JSON' errors
Comment: [Relevant](https://codeblog.jonskeet.uk/2010/08/29/writing-the-perfect-question/)
Comment: @L.F. Yes, Pocket Edition and Bedrock edition are now the same game.
Comment: Pocket Edition has been merged into Bedrock Edition, right?
Comment: Note that it is not at all needed to specify a version for MCPE, because since you can only use one version everyone is using one version


Are there "multi-frequency" signals within a human brain?

Question: I know that neurons can exhibit tonic and phasic firing, and also that a neuron is sometimes called an integrator. This makes me interested to know if there are activities in the brain that depend on two or more signals of different frequency occurring at the same time. For example, in a telephone system, two signals with a different frequencies at once(DTMF) are interpreted as 1. Is there anything similar in the human brain?
Answer: Remembering that neurons don't generate sinusoids, just spikes (mostly)....
It depends on exactly how you want to define "depend on".  For instance, a downstream neuron receiving inputs from two neurons will be more likely to fire as it spatially/temporally sums the inputs from the two neurons.  Regardless of their specific rates, if their interaction is such that an impulse from each neuron arrives within a certain timing of the other, it may be sufficient to cause the downstream neuron to spike.  In this case, particular sets of frequencies of the two upstream neurons would be more likely to activate the downstream neuron and would do so at a particular rate for the downstream neuron.  Of course, the phase delay between the two neurons would be important too.
In a more general sense, one might consider the binding problem, by which many sensory inputs are bound into a single, higher level experience, such as an object or a biographical memory, which can then later be recalled (and thus activate all the lower sensory regions that encoded the memory in the first place, nearly recreating the experience).
Answer: There is a somewhat-hypothetical phenomenon called cross-frequency coupling which has generated some interest recently. This has mostly been described in the hippocampus and in interactions between the hippocampus and neocortex.
http://www.cell.com/neuron/abstract/S0896-6273(13)00231-6
http://www.bio.brandeis.edu/lismanlab/theta.html
Answer: In general, drawing analogies of how the brain might work from engineered telecommunication/computing system can be quite misleading.
I just wanted to add Izhikevich's FM modulation theory of communication, but I would say it is controversial.

Izhikevich E.M. (1999) Weakly Pulse-Coupled Oscillators, FM Interactions, Synchronization, and Oscillatory Associative Memory. IEEE Transactions On Neural Networks, 10:508-526
Hoppensteadt F.C. and Izhikevich E.M. (1998) Thalamo-Cortical Interactions Modeled by Weakly Connected Oscillators: Could Brain Use FM Radio Principles? BioSystems, 48:85-94


What are some of the best wire framing pracitices/guidelines for mobile first approach for an ecommerce website?

Question: I'm working on redesigning a 90's ecom website - the goal is to make it mobile phone/tablet friendly and we have decided to go the mobile first way because the website has more mobile visitors. My first deliverable is a set of wireframes. Are there any best practices resources that I can refer to before I get started. Most of the info available online highlight the importance of having a mobile friendly website or delves a lot into css. I would appreciate any inputs on how I can get started.
Comment: Hi Tara, As it stands now the question is quite broad. Maybe you can tell what you've been looking at so far and ask a bit more specific?
Comment: Thanks for your response. I'm looking for some guidance on  how  to start the design process for the mobile website. Where do I begin? What do I look for? If I need to design for small, medium, large screens at the same time. How do I decide what's visible/hidden in each screen?  In the discussion with the devs, what should I be concerned about? I'm not sure if this is detailed enough.
Comment: "Where do I begin?" = determine the objectives of the site. Design from there.
Comment: There is no room for unnecessary things on mobile so start to strip away until it hurts, and then strip away some more.
Comment: There are best practices out there, but you have to decide what applies to your particular project. You can either start doing some sketches until you hit specific problems, or you can look at some design considerations and base your sketches on that. There is no right or wrong way to start, it is just based on how much you know already, and how much more you need to find out.
Answer: There are so many considerations, and if you looked up any articles on responsive versus adaptive design for the web/mobile you will come across most of the common ones. I have listed some here to get you started (sorry I don't have the exact references):
Mobile device considerations

Device orientation (optimized for each orientation or consistent look
and feel)
Display resolution (creating high detailed icons and
graphics for retina display)
Display dimension (adaptive or
responsive design to cater for variations)
Operating system
(backwards compatibility and version control)
Touch and gesture interactions (optimized for OS and device or consistent look and feel)

Responsive design considerations

What grid framework suits the content to be displayed?
Impact of using media query to determine device type
Designing scalable images and implementing them in the design
Maximum and minimum display widths supported
Are there logical breakpoints independent of physical constraints?
What are the key breakpoints when layout design need to change?
What do major templates look like at each breakpoint?
What do the header and footer look like?
Will content vary at different sizes/resolutions?
Navigation strategy at smaller display sizes
Table structure and content presentation at smaller display sizes
Browser compatibility issues

CSS considerations

Browser: Is the look and feel consistent and usable with the most current and popular browsers? Is it usable on older versions of various browsers?
Platform: Does the design work on PC, Mac and Linux machines?
Device: Does the design adapt to low-resolution and mobile devices that have full resolution?
Screen resolution: Does the design work for various window widths? Does the design does adapt to extremely narrow or wide viewports (e.g. by using the min-width and max-width properties)?
Font sizes: Does the design account for different default font sizes, and when the font size is changed?
Color: Does the design make sense and is the content readable in black and white? Does it work for color blind users or people who cannot distinguish low contrast details?
JavaScript presence: How will the page work without JavaScript?
Image presence: Is the content comprehensible without images (either background or foreground)?
Assistive technology: Is the page screen reader friendly? Is control/navigation possible with no mouse?

Some responsive design related articles:

http://alistapart.com/article/responsive-web-design
http://www.smashingmagazine.com/2013/03/01/logical-breakpoints-responsive-design/
http://www.netmagazine.com/features/top-responsive-web-design-problems-and-how-avoid-them
http://informationarchitects.net/blog/responsive-typography-the-basics/

Tools and Resources:

http://www.browserstack.com/responsive
https://quirktools.com/screenfly/
http://www.thismanslife.co.uk/projects/lab/responsivewireframes/
http://blog.cloudfour.com/a-comprehensive-guide-to-mobile-statistics/
http://opensignal.com/reports/fragmentation-2013/?

Let me know if you find any of it useful.
Comment: The question is admittedly broad, but this answer is about as useful as searching online 'mobile first'; it doesn't give an answer, but links to possible answers.
Answer: Worth looking at prototyping tools such as Axure or Proto.io which support mobile quite well. The latest beta of Axure 7 supports basic responsive layouts for mobile also.
Also worth keeping in mind, particularly with a mobile first solution is to keep it simple, keep the customer focused on one task at a time, and make tap zones large (7mm is a good guide as it's the typical width of a humour finger tap and isn't dependent on resolution). Also, allowing for those larger tap zones will force the design to simplify - and will make itself more amenable to porting, particularly to lower resolution Androids.
Before getting too caught up in responsive (or indeed more sophisticated adaptive design), it's worth asking whether responsive design is applicable for the user. Is the user actually performing the same tasks in a mobile context to what they're doing online? Nowadays it's better to take a multi-channel approach to modelling user behaviour and designing online and mobile offerings to compliment each other. It's worth looking at diary studies / qualitative testing etc to find out what it is that customers want to do on mobile ... and "are there other things that they'd expect to do online" ... this might help frame the conversation when discovering user needs. This is far more important to the success of the product than worrying initially too much about device compatibility etc - those discussions will come later.
With respect to creating "high detailed icons" - that's now becoming unfashionable particularly with the launch of iOS7 ... skeuomorphism is a thing of the past ... thing flat and simple. Also, this trend is also the norm / expected for Windows mobile and is also becoming increasingly common on Android devices also.
Other considerations include whether the mobile solution will be an app, a webapp, a shell-app - e.g. an app housing a web solution etc. A webapp, with a shell-app for appstore presence may be a good approach depending on the nature of the product.


Is there a parameter we can add to a KT1 contract so that it expires after a certain amount of blocks?

Question: I'm asking because I would like certain KT1 addresses return the funds back to the owner after a certain amount of blocks
Answer: No, there is no built-in function for this. However, it can be accomplished with a smart contract, that when called by the owner after a certain deadline returns its balance. Currently, the deadline must be specified as a timestamp, but future versions of Michelson may include a LEVEL instruction (see this merge request). It returns the block level of the current transactions, and so could be used to implement the behavior your describing.
However, there is currently now way of "expiring" or "suiciding" a contract in Michelson. Deployed contracts stay on the block chain forever. However, you can implement the contract so that after a certain deadline (specified using a timestamp or the LEVEL instruction described above), all incoming calls are rejected.
Comment: Thank you for your answer.  Say you reach that timestamp and there are still coins on the KT1 address, will those coins become untouchable in this scenerio?
Comment: If you write the contract so that it always fails after the given timestamp, yes the tokens will be locked forever.


how to configuring WIN 7 as Access point and using proxy

Question: [info] :

The connection : phone to computer to modem to internet.
Modem IP : 192.168.123.1
Computer IP : 192.168.123.1
Computer OS Windows 7
Phone connection : Wifi (using Internet Connection Sharing and addressed : 192.168.0.1)

[problem]
Computer internet connection can through proxy but when i using internet on the phone it directly connect to modem without go through proxy first.
How to configuring computer if want to all internet connection from both computer and phone through proxy?
Answer: It is easier to change proxy settings in browser on the phone, rather than configure the computer.
Unless the computer was a Linux, then you could install squid and reroute packets :-)


change profile default (custom field)

Question: I have an application form for students wishing to sign up for an audition. Our student records contain a custom "standing" field to indicate whether they are active (current students), inactive (past students/alumni), or applicants. This field does not appear in the application form, however when the form is submitted the records default to "active." I must have set it up when I created the profile, but can no longer remember or find where to change it. Any help on how I can change the profile to default to "applicant" on this form?
Answer: From your description it sounds like a custom field with specific options (either a select field, checkbox or radio button). If you go to Administer>Custom Data and Screens>Custom Fields, find the field group and field then click Edit Multiple Choice options. See if the option for "active" is marked as default. Edit the option and uncheck the default option.
Hope this helps.
Comment: Yes, concur that if there is a default value being loaded in a Profile, then it will be coming from the Custom Field, rather than a setting in the Profile Field itself.

change profile default (custom field)