Would it be possible to develop special relativity without knowing about light?

Question: My understanding of special relativity is that it is fundamentally based on the constancy of the speed of electromagnetic radiation - that this speed is a physical law (or derivable from physical laws and facts about the vacuum)  and not a contingent fact. Does that mean that, if humanity did not know about light (or electromagnetic radiation, generally), would we then be unable to come up with special relativity? To put it another way, imagine a species of intelligent life insensitive to electromagnetic radiation - no eyes etc. Would they still have a reason to produce the theory of relativity, or would they likely have created a physics framework which doesn't involve the speed of light so centrally?
Comment: We are insensitive to most of electromagnetic raditation. In fact, it took us quite some time to realize that visible light is just a manifestation of electromagnetism. Most of the electromagnetic spectrum is detected by specific instrumentation. If that species can develop a science, I don't see any reason why it could not develop those tools. It would only take the realization that some energy is going somewhere they don't "see".
Comment: It's easy to imagine. A blind man can use a radio to communicate. But radios transmit signals using the electromagnetic spectrum. So even an observer who can only detect things via sound would eventually discover that the true "speed limit" is the speed of light.
Comment: This is pure speculation because we have no idea what sort of society would be created by these blind creatures.
Comment: But isn't our notion of causality in part based on what an observer sees via light? What if an observer could only detect things via sound?
Comment: Of course it's speculation, it's a thought experiment designed to help explicate the centrality--or lack thereof--of light to special relativity
Comment: I think this question is not as speculative as some people are saying, so I've edited the question to (hopefully) make that a little clearer. @Richardbernstein, please check and make sure the new wording gets at what you would like to ask.
Comment: Surprising as it may seem, this actually happened, in some sense, in a
world where the are no electromagnetic waves to be analyzed. But the
beings there cheated because they communicated with Earth physicists,
so that they had some prior understanding of the concepts. Now that it
is done, we will never know whether they would have been able to do it
on their own. See the very end of my answer for more details (and if
it makes you unhappy, please tell me why, thanks).
Answer:
My understanding of special relativity is that it is fundamentally based on the constancy of the speed of electromagnetic radiation

Actually, no, that's true. Special relativity is (one could say) based on the existence of some speed that is invariant in all inertial reference frames. The fact that light (or anything else) travels at that speed is pretty much irrelevant. So while the development of SR was originally prompted by the constancy of the speed of light, it's not a requirement to have developed the theory. The effects of relativity would become apparent just from the time dilation/length contraction experienced by any sufficiently fast-moving object.
Answer: It is, in fact, possible to derive the mathematics of the theory of relativity without reference to light. David Mermin did so in 1984 (Mermin N D 1984 Relativity without light Am. J. Phys. 52.2 119–24). According to the abstract, "The relativistic addition law for parallel velocities is derived directly from the principle of relativity and a few simple assumptions of smoothness and symmetry, without making use of the principle of the constancy of the velocity of light."
So, being insensitive to electromagnetic radiation does not preclude the derivation of relativity, although the lack of a speed-of-light-centered theory (depending on how you define this) is still an open question. c might just mean something conceptually different to them, but it'll still show up.
Comment: This was done 73 years before Mermin: W.v.Ignatowsky, Phys. Zeits. 11 (1911) 972. A more recent exposition that's free online is Palash B. Pal, "Nothing but Relativity," (2003) http://arxiv.org/abs/physics/0302045v1 .
Comment: This the same as user16307's answer
Answer: N. David Mermin, Relativity without light.
Abstract:
The relativistic addition law for parallel velocities is derived directly from the principle of relativity and a few simple assumptions of smoothness and symmetry, without making use of the principle of the constancy of the velocity of light.
There is also a chapter devoted to this topic in N. David Mermin, Boojums All the Way through
Communicating Science in a Prosaic Age:
Note that I do not have access to either of those sources, although the OP may do, or he/she may wish to obtain such access.
Here is a free article Relativity without light: a further suggestion
Shan Gao on the related subject and its abstract:
The role of the light postulate in special relativity is reexamined. The existing theory of relativity without light shows that one can deduce Lorentz-like transformations with an undetermined invariant speed, based on homogeneity of space and time, isotropy of space and the principle of relativity...
Another free article, this one courtesy of CERN:  http://cdsweb.cern.ch/record/940058/
and its abstract:
Using only the reciprocity postulate, it is demonstrated that the spatial separation of two objects, at rest in some inertial frame, is invariant. This result holds in both Galilean and special relativity. A corollary is that there are no `length contraction' or associated 'relativity of simultaneity' effects in the latter theory. A thought experiment employing four unsynchronised clocks and a single measuring rod provides a demonstration of the time dilatation effect. This effect, which is universal for all synchronised clocks at rest in any inertial frame, is the unique space-time phenomenon discriminating Galilean and special relativity.
Comment: That paper is what I consider to be the best answer to what I think the question is asking. You should say more about the contents of that paper.
Comment: Hi user16307 - while this may answer the question, [it would be better](http://meta.stackexchange.com/q/8259) to include the essential parts of the answer here so that one doesn't actually have to click the link to know what you're saying. (Besides, the paper at that link is inaccessible to anyone without a journal subscription)
Comment: Nice answer. But could you please write out the authors and the titles of the papers you cited because the links may break (and actually are broken).
Comment: @ColinMcFaul Unfortunately I cannot say more about the contents, as I myself do not have access to the article, although the link was given for those who do, or wish to purchase such access, if deeply interested. I also added four more sources, two of which are free.
Comment: @DavidZaslavsky Thanks for the information, I'll try to maintain better standards for future answers.
Answer: Purely empirically, we have various atomic clock experiments that clearly demonstrate relativistic effects. There have been mountain-valley experiments demonstrating gravitational time dilation (Briatore 1979), experiments capable of separately detecting kinematic and gravitational time dilation (Chou 2010), as well as the famous Hafele-Keating experiment, which was sensitive to a mixture of gravitational time dilation, kinematic time dilation, and the Sagnac effect.
From the theoretical side, light plays no important role in the modern understanding of relativity, and the $c$ in all the relativistic equations is not really interpreted as the speed of light but as a conversion factor between time and space. It was realized very early on (Ignatowsky 1911) that special relativity could be developed axiomatically starting from assumptions about nothing more than symmetry principles such as homogeneity and isotropy of space. For modern, elementary presentations in this style, see Pal 2003 and this one that I wrote.
L. Briatore and S. Leschiutta, Evidence for the earth gravitational shift by direct atomic-time-scale comparison, Il Nuovo Cimento B, 37B (2): 219 (1979), http://www.scribd.com/doc/106593804/briatore-1977 . A very cool similar experiment by an amateur experimenter is described here: http://leapsecond.com/great2005/
Chou, http://www.sciencemag.org/content/329/5999/1630.abstract ; described at http://www.scientificamerican.com/article.cfm?id=time-dilation
W.v.Ignatowsky, Phys. Zeits. 11 (1911) 972. A more recent exposition that's free online is Palash B. Pal, "Nothing but Relativity," (2003) arxiv.org/abs/physics/0302045v1
Pal, http://arxiv.org/abs/physics/0302045
Comment: What about all the nuclear and particle experiments that show conversion of mass to energy? they would have forced special relativity to be interpreted much sooner than atomic clocks etc.
Comment: That is a great discussion in your book, and wonderful that you've made it CC BY-SA!
Answer: I have no idea whether scientists would have imagined relativity from
theoretical considerations alone.  But I do know that if they had not
developed it a century ago, they would be doing so now, with the tax
payer on their back. The tax payer would be eager to know why they are
not capable to have decent clocks to keep accurate time on bord the
GPS satellites, after spending billions to put them in place.
Now this does not exactly answer the question since there would be no
GPS without radio communication, hence electromagnetic waves. But I
guess it is still in the spirit of the question as light does not play
an essential role in the problem they would encounter.

Since I am downvoted, I will try to explain further. I would
appreciate the downvoter to explain why he does not agree with my initial
answer. At least that might teach me something
(and possibly others too).
In most cases, scientists work on a problem, on a new theory, because
there is a phenomenon they cannot explain, which was apparently the case for special relativity. Possibly it can also be to unify existing knowledge, which seems to be the case for general relativity.
So I wondered what would motivate people who do not experiment with
light, or who do not know enough about it to be able to measure its speed.
Another major phenomenon due to relativity is differences in local time.
My point is that the GPS depends on extremely accurate timing, so as
to have accurate knowledge of the positioning of the satellites, in order to give
precise positioning on earth. And both SR and GR affect the time on
board satellites (see Time_dilation in
wikipedia). http://en.wikipedia.org/wiki/Time_dilation I once looked
at the calculation, but all I remember is that without relativistic
correction, the time variation will amount to errors of several meters
per year (maybe per month). And it could be worse if SR and GR did not
have opposite effects.
For people who do not know about time dilatation, the effect of
relativity on satellite clocks would be seen as malfunction. (I read that this is precisely what the CMB looked like at first: antenna malfunction)
Now, if the use of radio for communication must be excluded. There
have been several experiments that measure time dilatation on earth,
as noted by @Ben Crowell.
Taking a clock in a satellite and bringing it back works too. That is
probably what would be tried with a copy of the "malfunctioning" GPS
clock. The interest of the GPS case is that it is now considered
a common appliance by most people, who are still surprised to learn that
its functionning involves relativity in a significant way.
But saying relativity can be derived from theoretical considerations
alone is not an answer if you will not provide experiments that will
show that it does make a difference. And if you do provide such
experiments, then they might as well be the original discrepency
between experience and theory that motivate developing a new theory.
Alternatively the new theory should at least be a unification of existing theories. But which should they be in the case of SR (I may have missed the point of some technical explanations of previous posts).
Another point is that Einstein thinking about the subject was
apparently also conditioned by his work on time at the Swiss patent
office.  I read that clock synchronization for railways stations was then
an important topic, and the subject of many patent
applications. Railways were still new. And Eistein was allegedly the expert on such paptents.
Finally, an interesting development on this is the scientific work of Leslie
Lamport in distributed computer systems (see the web). Synchronizing
clocks and dating events is important in a variety of
applications of distributed computing. The specialists had developed various (equivalent)
axiomatizations of the problem, but lacking fundamental understanding
of their justification.  Lamport justified these axioms by a physical
analysis of the problem which amounts to a qualitative version of the
theory of relativity, to which he explicitly referred.
So, it is possible that if the physicists had not developed the theory
of relativity, the computer scientists might have done it to some extent, at least
qualitatively.
Indeed, if people did not have electromagnetic waves, they would have
no radio, and thus they would rely a lot on physical transportation
which would increase the importance of clock synchronization issues.
Which brings us back to Einstein's work at the Swiss patent office.
Answer: I'd like to add to the answers of @BenCrowell, @DavidZaslavsky and @Mitchell. It's easy to get stuck on $c$ being the speed of light, since that is how the popular press define this constant in the iconic $E=m\,c^2$, and this leads everyone to wonder "what has light in particular got to do with it?". It is more helpful to think of $c$ as the freespace speed of a massless particle (zero rest mass) - a universal property of the World independent of the particular phenomenon (light in this case). It might also be helpful to imagine the following alternative possible history of physics, wherein special relativity comes before the Michelson-Morley experiment.
In this imaginary history, an Einstein-like character might well have begun by deeply questioning Galileo's relativity, wherein we add velocity vectors in the "normal", vector algebra way to work out transformation the of observed velocities, times and distances that happen when we shift from one inertial frame of reference to another. As well as adding vectors according to the parallelogram law in Galilean relativity, times and distances are the same for all inertial observers. Let's imagine our OWE (other world Einstein) asking the probing question - "is this the only logical way it could be?".
So then our OWE might make some VERY basic and reasonable assumptions about symmetry: if I transform from frame (1) to a frame (2) moving at a constant speed $v_{1,2}$ in some direction then my distance and time co-ordinates are transformed by some matrix $T(v_{1,2})$ (OWE is trying to find the most general form of the matrix function of velocity $T(v)$). If I then transform to a third frame (3), one moving at velocity $v_{2,3}$ in the same (original) direction relative to the transformed frame (2) (using the matrix $T(v_{2,3})$, this has to be equivalent to a single transformation $T(v_{1,3})$ from the first to the third frame with some relative velocity $v_{1,3}$. In particular, if frame (3) is moving relative to frame (2) at velocity $-v$, then frames (1) and (3) have to be the same and $T(v) T(-v) = I$ (here $I$ = identity transformation - my running away from you at velocity $v$ should seem the same as your running away from me at the same speed in the opposite direction). This symmetry arises from a basic "homogeneity" (space and time are the "same" in some sense everywhere) and the Copernican notion that there is no special frame. Notice how one has NOT assumed that $v_{1,2}+v_{2,3} = v_{1,3}$, aside from in the special case of when $v_{1,2} = -v_{2,3}$.
Now, if our OWE makes these assumptions ALONE (see the  Wikipedia entry  (cf Ignatowsky 1911 cited by @BenCrowell) he or she would find that not only is Galilean relativity a possibility, but that there is a whole class of relativities possible, with one unspecified velocity parameter $c$: their transformation equations all have the same form but the $c$ parameter is different. Galilean relativity is the relativity that one gets as the $c$ parameter goes to infinity.
So our OWE says to themself: "we've been assuming Galilean relativity all along, but what if the $c$ parameter for our World is just very big, not infinite, so that we've hitherto not measured it as finite. What experiments could we do to find out what $c$ is?". After some work with a relativity with a finite $c$, OWE would deduce that:

$c$ would be measured to be the same in all inertial reference frames. Moreover, so as to enforce this invariance of $c$, there would be a peculiar addition rule for velocities not quite the same as the parallelogram rule;
No material object can go faster than $c$ and indeed something can travel at speed $c$ only if it has a rest mass of zero.

So now along come Michelson and Morley with their famous experiment. As it happenned, their experiment implied that the speed of light is the same in all inertial frames. The addition rule for velocities is the same as OWE's weird equations if we take $c$ to be the speed of light.
So now, in this other World, the Michleson-Morley experiment has the following interpretation: Galilean relativity is almost certainly wrong, because we've found something that behaves just like OWE's predictions assuming a non-infinite $c$. Moreover, light MUST be a massless (zero rest mass) thing.
Notice how too if a positive result would have been gotten from the MM experiment, this would ALSO fit in with OWEs thinking. Suppose the MM experiment showed a delay difference of a few fringes depending on the interferometer's direction. Suppose there were only a very few fringes - definitely not a null result, but way too few fringes to be consistent with Galilean addition of aether and Earth velocities. Then this would also support OWE - the failure of Galilean addition would show that there is probably a finite value of $c$, but the fact that the result was not null would show that the speed of light were not quite as great as the universal speed limit $c$. Moreover, the MM experiment in this World would conclude light has a rest mass, which one could estimate from the experimental result and moreover one could deduce a good estimate for the value of $c$ as well.
Answer: Albert Einstein was largely motivated by Maxwell's equations and the electromotive force in particular.  So it would be quite possible to develop special relativity without the special case of light.  Amphere's law is a relativistic effect, so that would be enough.
Answer: No, it wouldn't be possible to develop special relativity without light. Scientists developed a model of the propagation of light in a material substance called the ether based upon what they knew about the propagation of sound waves in a medium. Their expectation was they would be able to detect the speed at which the Earth travelled through it, but experiments gave a null result which scientists found initially confusing. Eventually this gave birth to the Special Theory of Relativity.
You therefore need to know about light behaving differently to what you know about sound, to see there is something interesting going on.
Comment: This does not deserve a -3. It is true that at least not so early, would SR have been developed, if there were no light.
Comment: @Dimension10 wise words from... you're only 13? I'm shocked and awed at the same time.
Answer: What if Bats indeed would have been intelligent? :)
Think about it like that:
Any changes requires signal trasmission of ANY kind (in bats case sound in the air).
There are 2 cases:
1) Signal trasmission is infinitely fast - in this case we get Galileo-Newton mechanics.
2) Signal trasmission is finite - in this case we have SR.
What is signal? Signal is a general process(phenomenon) by which far world ALIENS determine such conceptions as SPEED, TIME and so on (we use light for everything). If they dont have these conceptions then we are in trouble and we can not asnwer your question casue WE DONT KNOW, but if there is some sort of speed and time variables in their physics picture then they will rediscover special relativity.


Travelling to Northern Cyprus on Turkish e-visa for Pakistani national

Question: I am a Pakistani national and holder of a multiple entry US/Schengen visa, can I travel to northern Cyprus (Lefkosa via Ercan International airport) on a Turkish e-visa?
Answer: You don't need a Turkish e-visa, just a valid Pakistani passport.
No one except Armenians and Nigerians need a visa to visit North Cyprus.
However, be warned that, when checking in for the flight to Turkey (because you need to connect there), because North Cyprus isn't recognised by the international community, when Ercan is selected as the destination in the database, the rules for South Cyprus will appear. Therefore, it will first look like you need a visa.
HOWEVER, further down it says:

Warning:
  - These entry regulations apply only to the part of Cyprus
    controlled by the government of Cyprus (i.e. they are not
    applicable at Ercan (ECN) and at Gercitkale (GEC)).
   - For entry regulations applicable at Ercan (ECN), see:
     http://mfa.gov.ct.tr/consular-info/visa-regulations/

And in that link, it says (admittedly not in clear, direct terms) that only Armenians and Nigerians need a visa.
As for transiting Turkey:

TWOV (Transit Without Visa): - Passengers with a confirmed onward ticket for a flight to a third country within 24 hours. They must stay in the international transit area of the airport and have documents required for the next destination.

So again, you only need your passport, but be prepared to have to point to the TIMATIC sections I quoted (the check-in staff will see it)
Comment: Thanks for your reply guys.
But just wondering, i really need visa(or evisa) to travel to turkey. This is what i have been doing previously.

But i wont need visa to TRNC? Seems strange...

FAQ# 4: https://www.evisa.gov.tr/en/info/
Comment: @Mohsin That's correct: you need an e-visa for Turkey but not for North Cyprus.
Answer: Thanks a lot for your help.
I have checked with Turkish e-visa section and this is what they said which quite complies with what you guys suggested.
"If you will go to Turkish Republic of Northern Cyprus through Turkey, you may use an e-Visa to travel. However, if you will go directly to Turkish Republic of Northern Cyprus, kindly proceed to the nearest Turkish mission to complete a visa application"
So just to be on safe side, i will take a Turkish e-visa and fly via Istanbul to TRNC.
Comment: They are completely wrong, period! Turkish authorities don't decide North Cypriot rules. You don't need a visa or e-visa at all, except if you leave the transit area at Istanbul airport
Comment: Hello Guys, I am in Lefkosa now. But the problem is, i came to Turkey on e-visa and while coming to Ercan, they stamped my passport with exit stamp. Now I need to go back to Dubai via istanbul after 2 days. Since my e-visa is not valid anymore(single entry), do you think i can fly to istanbul, stay in transit area and then fly to Dubai(i am resident of Dubai).?
Comment: As I've explained **your e-visa is not needed for transiting Turkey**. Therefore, if you stay in the transit area in Istanbul, you're completely fine.


What is the Islamic view of seeking blessings from prophet's hairs?

Question: Is there any basis for seeking Barakah (blessings) from Prophet's hair?  What is the Islamic View Point for this? Can I practice tabarruk?
Answer: According to Ahlus-Sunnah, There is no doubt that it was narrated from the Prophet (peace be upon him) that the Sahabah (Companions of the Prophet) (may Allah be pleased with them) would seek blessings from the Prophet's leftover ablution water, hair, mouth spittle and nasal expectoration. These practices were authentically reported about the Prophet (peace be upon him) and the Sahabah (Companions of the Prophet).

It was authentically reported in the Hadith narrated by Abu Juhayfah
  in the two Sahih (Authentic) Books of Hadith that during the Farewell
  Pilgrimage, when Bilal stepped out with what was left of the Prophet's
  ablution water, the Sahabah (Companions of the Prophet) rushed to take
  it; some of them took a little of it and others took much.

It was authentically reported that there was a blessing in his body, sweat, hair and all the parts of his body. Also, the Prophet (peace be upon him) approved of the Sahabah (Companions of the Prophet) regarding seeking blessings from his belongings. If it had not been permissible, the Prophet (peace be upon him) would not have approved of it.

Also, when the Prophet (peace be upon him) had his hair cut during the
  Farewell Pilgrimage, he divided his hair into two halves; a half to be
  distributed among the Sahabah (Companions of the Prophet) and the
  other to be given to Abu Talhah (may Allah be pleased with him).

These all were authentically reported from the Prophet (peace be upon him). There is no doubt among Muslim scholars on the blessing of the Prophet's body including his hair, sweat, ablution water and all that touches his body.
However, This type of barakah of the physical essence was cut off after the death of the Messenger (sallallaahu alayhi wasallam) except what remains of his physical essence after his death (eg. Hair). However, the certainty that something remains today and the truthfulness of that has diminished after the passing of time. Anyone making the claim has to provide isnaad to show that something is from the Messenger (sallallaahu alayhi wasallam) since many make that claim. Moreover, things like hair decompose with time and it is not realistic to expect them to survive after 1400+ years.
Moreover, this form of worship is only restricted to the Prophet (salallahu alayhi wassalam) alone. This is proven since the Sahabah (Companions of the Prophet) (may Allah be pleased with them) did not do similar practices with Abu Bakr Al-Siddiq , Umar , Uthman or Ali who were the best of the Sahabah (Companions of the Prophet). They are the best people after the prophets. So, tabarruk from anyone other than Prophet salallahu alayhi wassalam) is not permissible, according to Ahlus-Sunnah.
References: Chapter on Tabarruk ,
The Understanding of Tabarruk with Ahl us-Sunnah
Comment: @Ahmadi What was cut off by death is the tabarruk by physical essence except what remains after death like hair. Obviously today no one has access to Prophet (salallahu alayhi wassalam)'s sweat or ablution water. Secondly, there is no sect called Saudi Wahhabism. I have mentioned sunni in my answer. You were warned about inflaming at other answers/opinions/sects before.
Comment: today hair of prophet is avilable in musems and also his grave and many of his prperties like cloth, shoes, sword etc are avilable in Saudi musems and other musems.
Comment: @Ershad you may want to mention that hair, cloth, etc. all decompose. It's not realistic to expect them to survive 1400+ years.
Answer: (This Answer is according to view of Shia scholars)
Is there any basis for seeking Barakah (blessings) from Prophet's hair?
By referring to the last chapter of Sahih Bukhari about jihad and also the chapter related to the armour, stick, sword, vessels, seal, ring, hair and shroud of the Holy Prophet (s) one can become aware of the evident examples of tabarruk.
Even the Sahaba asked Tabaruk from grave of prophet after his death.
What is the Islamic View Point for this?
All Shia scholars consider Tabarruk (including anything related to prophet and today mostly to grave) of prophet and Ahl Bayt permissible and even recommended. For example, there are many holy shrines of Ahl Bayt in Egypt; even Sunni Muslims visit them and ask Tabarruk from them.
Can I practice tabarruk?
basically Tabarruk is seeking blessing from God using the high love of God to prophet and if the hair of prophet has cure it is for love of God to prophet and a hair itself has no value. Tabarruk can be practiced to anything related to prophet including hair. But today if you want you can use grave and tomb of prophet. According to Shia not only it is not Haram but is allowed.
Some evidences for seeking Tabarruk from grave of prophet after his death:
(1) After the Holy prophet's burial, his daughter Fatima ('a) stood near his grave and then taking some soil from the grave she put it over her face. She later cried and recited these two poems:
"What happens to the one who smells the soil of grave of Ahmad, who till he is alive, shall smell no more the expensive musks".
"I was faced with such calamities that if it had befallen on the bright day it would have changed to night" [Many of the research writers have narrated this incident such as al-Shabrawi in al-Tuhaf page 9 and al-Samhudi in Wafa' al-wafa', vol. 2 page 444 and al-Khalidi in Sulh al-'Ikhwan, page 57 and others.]
(2) The great companion Bilal who left Medina for some reason and settled by order of the frontier guards, in the districts of Syria saw in his dream that the Holy Prophet (s) was saying:
"What kind of injustice is this, O Bilal? Has not the time come that you visit us!? He woke up from his sleep in sadness and sat on his horse and left for Medina. When he reached the grave of the Holy Prophet (s) he started to cry and rubbed his face over it. Later he saw al-Hasan and al-Husayn and kissed both of them. [This incident has been narrated by a group like al-Subki in Shifa al-Saqam narrating from Ibn 'Asakir, and Ibn al-'Athir in Usd al-ghaba, vol. 1 page 28.]
(3) Amir al-mu'minin 'Ali ('a) says: "Three days had lapsed from the burial of the Holy Prophet (s) when a Bedouin Arab came and threw himself over the grave of the Holy Prophet (s). He sprinkled the soil of his grave over his head and started to converse with the Holy Prophet (s). He said: 'O Prophet of Allah, you spoke and we listened. You received the truth from Allah and we too received it from you. From the things which Allah revealed to you is this
I have done injustice upon myself. So seek forgiveness for me from Allah. Suddenly he heard a voice saying: Your sins have been forgiven.
This incident has been narrated by most of the historians mainly al-Samhudi in Wafa' al-wafa', vol. 2 page 612 and Shaykh Dawud al-Khalidi (died in 1299 AH) in Sulh al-'Ikhwan and others.
(4) al-Hakim narrates in al-Mustadrak that: Marwan bin al-Hakam entered the mosque and saw a man putting his face over a grave. Marwan caught hold of his neck and said: "Are you aware of what you are doing?" The man lifted his head and it became apparent that he was Abu Ayyub al-Ansari. He said: 'I have not come to visit a stone, but have come to visit the Holy Prophet (s). O Marwan, I have heard the Holy Prophet (s) saying: When the pious people bear the leadership do not cry for that. Do cry when unworthy men become the leaders (i.e. you and your Umayyad household).' [Mustadrak al-Hakim, vol. 4 page 515]
This period of history reveals the root of 'creation of obstacle' to prevent seeking tabarruk from the grave of the Holy Prophet (s) and shows that the companions of the Holy Prophet (s) were constantly seeking tabarruk from the holy grave of the Holy Prophet. It was people like Marwan bin al-Hakam who used to prevent people from this well-known deed.
The historical incidents in this case are so numerous that narrating all of them will lengthen our discussion. Interested readers can refer to the book Tabarruk al-sahaba and the valuable book al-Ghadir vol. 5 page 146-156.
References and more info:
Seeking Benediction and Cure from the Signs and Traces of Awliya
Tawassul {Resorting To Intermediation}, Death and Shafa'Ah {Intercession} According to the Shi`ah and the Wahhabis
Performance of Prayer and Supplication Near Graves of the Holy Personalities
Al-Baqi'
Rebuild Jannat-ul-Baqee Movement
Destruction of early Islamic heritage sites
Comment: The question is about hair specifically? Why bring in grave?
Comment: @Ershad actually this qustion is about Tabarruk and not about hair itself. there is no difference between heir and other things related to prophet about Tabarruk. if it is proved tabaruk to water is allowed so to hair also allowed. bringing grave is like bringing water.
Comment: As far as I can see the question specifically asks about hair. I asked why did you bring the tabarruk to grave thingy + Saudi Wahabbism stuff?
Comment: @Ershad in my view hair is only one example of Tabarruk and main sublect is Tabarruk and not hair itself. also I bring for the same reason you bring water of wudu of prophet. and cut of Tabarruk to physical properties of prophet by his death is only beeif of non-Shia sect and this should be cleard in answer.
Comment: This answer is good, but it should be worked to better emphasise the point that tabarruk of hair is the same as tabarruk of graves.  The grave-specific evidences can also be cut back or summarized to better improve readability, since the question is more specifically about the hair not tabarruk in general.
Comment: @goldPseudo thanks for your edits. I improved the answer and categorized it. question is two part. one about hair and one about Tabaruk in today. (Can I practice tabarruk? )
Answer: Do we worship the black stone in Kaaba?
Can that stone bring you any good or bring you any harm?
That stone is our priced possession, but still "nothing is worthy of worship except Allah".
Similarly the prophets (pbuh) hair is a priced possession but still can't answer your prayers (like seeking blessings)
The hair may have healing powers like the cloak of Yusuf (pbuh), but only with permission of Allah.
So seek blessings of Allah...
Answer: According to a saheh hadith I have read some time ago, when rasulullah (May Salat and Salam be upon him) has witnessed people collecting his cut beard, he told them it is better if they rather focus on his teachings.
P.S: I don't have the reference to the source right now, but it is in one of the famous, legitimate hadith books. Maybe someone can edit this answer and quote it.
Comment: are you sure the hadith says he cut his beard?
Comment: @Ershad Yes. He might be trimming it. Because according to another hadith from Aisha (May Salam be upon her) he trimmed his beard.


How to find an English-speaking general practitioner in France?

Question: I'm in need of a general practitioner visit and I'm in Paris. Is there any way to know which ones speak English, because it's quite uncommon that people speak English well here, and I don't have enough French to discuss my medical condition. (I have an EHIC card to cover my expenses, I'm aware that I'll likely have to pay something extra, that's not the issue now.)
Comment: Do you speak any French? In my experience in Paris, it's often amazing how little English people speak until you try some French, then it's amazing how much they speak once they've seen you make an effort...!
Comment: @Gagravarr I do speak some French, and I have the very same experience as you. However, if the doctor doesn't know the right English vocabulary, we're lost again somehow...
Comment: In the UK the NHS has a GP search service, which also lets you filter by languages the doctor speaks. Highly useful! I couldn't find something similar for France unfortunately
Comment: @SztupY GP in France are self-employed, the structure is completely different.
Comment: @GaëlLaurans: GPs in the UK are also self-employed, but they also have to sign a contractual agreement with the NHS.
Comment: @SztupY The structure seems more similar than I thought.
Answer: Embassies often have lists of doctors that speak the language of the country in question. I would call them and ask if they have a recommendation. That's how I found doctors in Asia.
The UK Embassy in France lists for example a link to to AngloInfo, which in return has this page here about healthcare in France.
The French  US embassy has a list of English speaking doctors and hospitals.
The  French Australian embassy has another list of English doctors.
I would generally assume that the further away you are from home, the better such information and help from the embassy becomes. A majority of UK citizens can probably go home in time in case they need a doctor, which is much harder for someone from the US or AU. So if you have several countries in the world that speak your language, try to find a larger one that is rather further away, and you might get more detailed help on their website.
Comment: But on the other hand the UK embassy might care about EHIC coverage. (+1 in any case, was also my first suggestion)
Answer: Your consulate might have a list but that's a long shot as they are not always up to date (I know the US does something like that but I don't know if they would help non-US citizens and then they might refer you to an expensive private clinic like "Hôpital américain"). You could at least check the websites of several consulates, in case they publish it.
I know that international travel assistance services like ADAC in Germany also suggest in their promotional material that they can help you find a physician but in that particular case it would be a German-speaking physician and their lists are hopelessly outdated in my experience (e.g. include people who retired several years ago). Of course, you also need to be a member in the first place.
Another idea (but also something of a long shot) would be to call SOS Médecin. They provide house calls for non-life threatening emergencies ("urgences non-vitales") so pretty much your situation (unlike 112), and might be able to pick the right person from their own list of GP. If you do get a house call be aware that you will be charged more if the physician considers that you could have come to his practice.
Finally, expats often exchange names/contacts of English-speaking GP on local forums. I don't know any for Paris but a web search turned up something that looks potentially useful.
Comment: If you search for "Anglophone doctor" you get a site from the Australian embassy containing English speaking doctors: http://www.france.embassy.gov.au/pari/engdoc.html
Answer: I live in Antony, just south of Paris, and I couldn't find comprehensive information about english speaking doctors. In general, I have to phone a doctor (GP or otherwise) to make an appointment and soon find out if they speak english, while I'm talking to them with my lousy french.
If you can find email addresses for the GPs near you, then that might be a simpler way of finding out if they speak enough english to help you - and less stressful than a phone call with a secretary who might have no interest/patience/might be trying to quit smoking... I have been hung-up on by more than one who just can't be bothered speaking slowly, twice. I still email my OB/GYN because he speaks english but his secretary does not (ahem, have a heart).
There is an organisation in Paris, aimed at anglophone parents, called MESSAGE. They have fantastic forums full of information on all sorts, including much medical stuff. You do have to join Message to access the forums, and it costs, but if you're in Paris for a while, it might be worth it. If you have kids, definitely!
Answer: There are several websites where you can book a doctor's appointment online. This isn't a central doctor database: membership in each website requires the doctor to register and pay a fee (what doctors get from it is more publicity).
Many of these sites just give the doctor's specialty, name and address but a few offer more. Note that I am only asserting that these sites exist, I cannot vouch for their accuracy.

Rendezvousfacile — allows spoken language as a search criterion, and has a user interface in English. The downside of this site is that it doesn't have many participating doctors.
Mondocteur — you can't search for English-speaking languages but doctors have short bios, some of which mention "anglais". You can search doctor bios with Google.
Answer: i have been to the following family practice of 3 young general practictioners www.ipso.paris, and all the physicians claim to speak English.
The one i saw actually did speak good English
Answer: In similar situation I tried to contact private clinics - there must be plenty of them in Paris, and I suppose they have also English websites. I phoned the call center, and I got quickly an appointment, requesting an English speaking doctor (I realized later that the doctor's idea about being fluent in English didn't meet mine completely, but that might had been only my bad luck).
I am not fully aware how EHIC works; my insurance handled the costs afterwards, there was a bit of paperwork, to a survivable extent.


how to survive if you are hanging on to some aveiros

Question: Is there a strategy or saying / quotation (chasidish, chazal, etc.) that addresses what to do if there are some aveiros that one is not ready to give up on but wants to feel good about doing the other mitzvos?  Sometimes these aveiros become big in my mind and I can't concentrate on doing the other things.  I guess it feels like "all or nothing" and I feel like it would be better to not be frum at all.  How to fight this?
Comment: I wish you great success in working through these issues and growing in your Jewish expression. The way you're formulating some of your challenges as specific requests for information here is potentially very useful, since it gives you a chance to get advice from many perspectives and also creates a resource for other people who search the Internet with similar questions. I recommend that you complement this practice with a relationship with a rabbi/rebbe/mentor who can learn more about your particular personality and needs and provide more targeted advice. But keep up the great questions!
Comment: Great question!!
Comment: One of the ultimate life-questions!
Answer: Here's one I know of.
In the last mishnah of Yoma, R' Akiva says that "just as a mikvah purifies the impure, so does Hashem purify Israel." The Lubavitcher Rebbe zt"l points out that the phrase "the impure" seems to be unnecessary; of course, those are the ones who'd be using a mikvah in the first place.
And he explains: in halachah, a person can be tamei (impure) in various ways (for example, he might have come into contact with a corpse, and also with a dead animal's carcass, and also by being a metzora, etc.). Only some of these are purifiable via the mikvah; others require other procedures. Nevertheless, the mikvah is indeed effective in purifying this person from certain kinds of impurity.
In the same way, then, he explains, R' Akiva means to say that Hashem is willing to act as a mikvah in this sense. Even if a person is not yet ready to do teshuvah for all of his or her misdeeds, Hashem will accept that person's teshuvah for what he or she is ready for, and forgive those - so that now they can start psyching themselves up to do teshuvah for the next thing, and onward.
Comment: The Lubavitcher Rebbe isn't alone in saying this, and he's not really deriving a chiddush from an obscure drasha on a paseuk. The whole idea is pretty clear in the Ramchal's Derech Hashem where he discusses how the purpose of creation is so that Hashem can bestow good on a person commensurate to his actions in this world. Thus it's up to you what your actions are -- if you're very effective at some mitzvot and not others, your reward will be for the mitzvot you were effective at. (But remember not to understimate what you're missing out on in Olam HaBa if you can't tackle the averirot...
Comment: טובל ושרץ בידו means exactly that - a person who is trying to become tahor from a particular kind of tum'ah while still holding on to it. In the analogy, it is a person who does teshuvah hypocritically, saying that he's sorry for what he did but thinking that he'll do that same aveirah again. Here we're talking about two different aveiros, where the person sincerely regrets one (and will never do it again) but isn't yet strong enough to give up the other - which is akin to the halachic case of a person who is tamei in two different ways and who is immersing himself to get rid of one of them.
Comment: While this makes sense for misdeeds in the past, the original question regards one who continues to sin.  Wouldn't this be more analogous to going to the mikveh with a sheretz in your hand?
Comment: ... that you're currently lacking in.)
Comment: I don't know that this is necessarily the same thing, though. Based on your summary of what Derech Hashem is saying (and I haven't learned it), you could argue that there's a difference between passive non-fulfillment of certain mitzvos (where indeed, failing to observe one of them out of laziness, or whatever, doesn't necessarily taint the other ones) and active disobedience.
Answer: I recommend that you take a look at the works of R' Dr. Abraham J. Twerski. He's a rabbi with a very strong Chasidic heritage, a major psychiatrist, and a prolific author. Self-esteem is a very big theme in his books. I haven't read it, but one title that looks like it's aimed very close to the issue you're describing is Angels Don't Leave Footprints: Discovering What's Right with Yourself.
Answer: No person is completely free of sin (Kohelet 7:20). This does not prevent anyone from doing Teshuva, at least for those sins he's ready to abandon.
Humans are referred to as "mehalchim/moving", as opposed to angels, who are referred to as "omdim/standing". Angels' spiritual level is frozen and cannot be altered. By contrast, humans are never standing still; rather, a human being is always moving, either upwards or downwards. God expects humans to strive to always move upwards; where exactly you are on the ladder is secondary.
Rabbi Dan Segal explained a verse in tehillim "זדים הליצני עד מאד מתורתך לא נטיתי": sins I have committed intentionally pressured me, but I haven't strayed from your Torah. King David was tormented by personal failings but didn't let them deter him from Hashem's service. There is a well-known Chassidishe saying that the Yetzer Hara isn't after getting you to sin as much as getting you to feel depressed about it afterwards.
Advice which has worked for many people (including myself): Instead of obsessing over the here and now, formulate a 12-month (or 5-year) plan in which you take upon yourself teeny little baby steps that move you away from a particular practice you wish to drop. Every move is a victory and should be celebrated. Eventually, with God's help, you'll get to where you need to be.
Comment: Well said.  A small step may be to choose a practical time period where you will absolutely not do the sin.  Say, depending on the issue, one day a week.  And yes, celebrate that success, even if you waited until 12:01 AM and then did the aveirah, you were successful.  Many may choose Shabbos as the day since it is holy, but keep in mind that it is also a day you are more idle and more likely to give in.
Answer: Mishlei states:

מִי יֹאמַר זִכִּיתִי לִבִּי טָהַרְתִּי מֵחַטָּאתִי

Who can say they are free of sin? (loosely translated)
Man by definition is imperfect and will sin.  No one is perfect.  No one is without sin.  We live in a society were a premium is placed on accomplishment, goals and how people view us.  The key is to be involved in the process of developing oneself, full well realizing that we may never be perfect.  The process is what is more important.
In fact Chazal say that

במקום כפרתי נברא ,in the place man was created was atonement.

Man must recognize and acknowledge he is a sinner.  We must be honest with ourselves.  Honesty is probably one of the most difficult things to do.  I applaud you for being honest with yourself about what you can do and what you can't do.
The third point I would like to make is regarding that overwhelming feeling you have regarding your sins  We have a part of us that let's us know we are doing something we may consider wrong.  This is our conscience. Our feeling of guilt, fear and shame.  We often have a view of ourselves.  We imagine we "ought" to be one way.  When we don't measure up we feel pangs of guilt.  However, our guilt is really just an emotional response that is based on our image of what we imagine to be correct.  This image is often formed and influenced by our parents, friends, society.  If we lived in a different society we may feel guilty about some other issue.  (For example a member of a cannibal tribe may feel guilty leaving over a limb).  The guilt can be a tool or an alarm telling you to think about what you are doing.  But you can't let it rule you.  You need to evaluate with your mind and determine if the decision you are making is the best decision. The Torah's view is not an all or nothing approach.  So, although one may feel guilty about only keeping part of the mitzvot, they must intellectually realize this is the best approach for true growth and development.  Our society is a christian society that emphasizes sin is evil and promotes a guilt, fear and shame attitude.  However, according to Torah חט really translated better as one missed the mark. It is true one may miss the mark in one area, but they certainly can make progress in other areas of their life.
It is challenging to get past the guilt, but I hope that this awareness can help you address the guilt and not allow it to occupy your thoughts.  If you want I can offer further thoughts on how to address the guilty feelings, if these ideas don't completely help.
I applaud your pursuit of the truth and the path to development.  Keep up the great work!
Answer: For more answers, see:
R' Mordechai Becher; R' Moshe Newman. After the return: maintaining good family relations and adjusting to your new lifestyle—a practical halachic guide for the newly observant. Chapter 1: "Evolution or revolution?"
(Please note: The book was written for ba'alei teshuvah. Page 9 warns that many of the rulings in the book are forbidden for non-ba'alei teshuvah to follow.)
Answer: this is a tough one, because my experience is that people with this attitude NEVER get out of this mentality.
sounds to me like you need to hang on a few years until you have more maturity, and at some point you'll need to make that decision of which side you're on.
Because, really, you can't play games with Gd.
my $0.02
Comment: Your first paragraph contradicts your second: the first says people never get out of the attitude, and the second suggests that the asker might do so in a few years.
Comment: good point. the answer is: if it's due to being young and immature then there's hope. my experience is OLDER people (middle age and beyond) who have this attitude never get out of it.
Comment: come to think of it, what i said is explicit in the talmud (yoma 85b) "one who says 'I will sin and repent' is prevented from doing teshuva", all the more so one who says "I will sin and will not repent"


What can I use for a small-batch fermentation vessel?

Question: I would appreciate if it was cheap. Also, I saw somewhere you could use a UTZ container from cheese balls. Has anyone tried that?
Comment: Whats your batch size?
Comment: I am making a one gallon batch of blackberry wine.
Answer: Depends on batch size. If your doing 2-3 gallons. I would recommend using glass 1 gallon jugs from wine or Apple juice.
The cheeseball containers I believe are made from the same foodgrade plastic as 2 liter soda bottles. They are novel in that they have more volume and a large opening for dry hopping.
I think either would be a good fermentor untill you can get into 5 gallon batches using a carboy or brew bucket.
Set the goal to use glass or stainless steel when you get into larger batches.
All plastics have sanitation limitations. Basically if they get scratched they can't be relied on to be sanitary anymore.
Answer: If you live near a good juice bar or restuarant that serves smoothies, ask the sales clerk if they have any empty glass jugs.  Many drinks have an apple juice base and organic apple juice often ships in 1 gallon glass jugs.  I've found two shops that happily give the jugs away for free, though I usually buy a smoothie in gratitude.  Being a tipping patron helps to keep the jug supply flowing.
My favorites have a glass ring at the top for easy carrying and take a #6 rubber stopper.  I get them at the juice bar of my local Whole Foods supermarket.
Answer: Check at your local bakery. Most of them get frosting in 5-10lb buckets. These are (obviously) food grade and have a good seal. Likely they will simply give them to you if you ask. You might have to enlist some small children to help you get the last of the frosting out of the bucket :), but after that and a good rinse with hot water all you have to do is drill a hole for an airlock and install it with a grommet.
Answer: There are a lot of good answers here, but I'd like to chime in with my favorite small-batch fermenter.
For small, 1-gallon batches, I like to use 4L glass wine jugs (I typically use Carlo Rossi, but any brand will do as long as it's glass). Since the jugs are a little larger than 1 gallon, they also offer a bit of extra headspace, so you can actually start with a full gallon (ie, make more wine).
The wine itself is pretty cheap (~$12-$15 USD) and is usually passable. If you can't bring yourself to choke it down (or find some friends to help out), it's usually decent for cooking. Some homebrew shops also sell the empty jugs for ~$2 -$3 USD (YMMV, of course).
TLDR: For less than $15 USD, you can get 4L of wine (yay?) and a sturdy small-batch fermenter that will last for years.


Japanese Trickster Demons

Question: Are there any trickster demons in Japanese mythology, I am aware of the somewhat tricksy Japanese god Susanoo-no-Mikoto, but are there any demons known for tricking people in Japanese mythology?
Comment: I'm not sure there's any. Kitsune and tanuki are often seen as tricksters but calling them demons would be a bit harsh.
Answer:
Tengu (天狗)

A lot of my knowledge about them comes from the oral tradition, but the Wiki makes an interesting point that they were originally regarded as demons in the Buddhist context.  In the Shinto contexts, they were simply yōkai (妖怪).
Tengu are often thought of as a type of forest goblin, and may be benefactors or adversaries, which is typical of tricksters.
Tengu are known for their long noses and, often, their martial skills, particularly with the sword.
Comment: Please include some example of these stories in the post, to demonstrate how tengus are tricksters. I think it would be a great improvement to your answer.
Comment: Many of the old koryu sword schools tell of Tengu teaching the first headmasters their craft. Particularly within the Yagyu Shinkage Ryu style (See the sword and the mind).  Tengu are often subtle references to the Iga Ninja
Comment: @Semaphore Most gods/goddesses are either good or bad.  Tricksters occupy a grey area, where they can be either.  Often you have tricksters like Prometheus, who is *only* an adversary to Zeus and *only* a benefactor to humanity, but is Prometheus good or bad?  (He goes against the will of god...)  Loki is an example of the trickster who is both benefactor (walls of Asgard, etc.) and nemesis (Ragnarok, etc.) The story of Sif's golden tresses is a great example of mischief leading to benefit—not only her golden headpiece, but the creation of other objects, including Odin's spear, Gungnir.
Comment: @Semaphore I wouldn't say "defining trait", but certainly a fundamental quality of all tricksters.  Good tengu/bad tengu would seem to qualify the race in general for trickster status, and they would seem to have that feeling, whether benefactors or nemeses.  Consider the "treat or trick" convention: in many stories, the Tengu will bless your efforts if provide them with a tasty tidbit, and cause mischief otherwise.

Japanese Trickster Demons


Translating "the price of independence" into French

Question: If you translated the phrase "the price of independence" very literally into French, would it have any meaning for a native speaker? Or is there some idiom that better conveys the meaning?
Comment: It may depend on the context, so you may want to give some more context.
Comment: "le prix de l'indépendance" works fine for me!
Answer: It depend of what you mean by "independance", if you mean more like freedom (from something or just Freedom) or being able to provide for yourself and not to respond to anyone.
So if it's freedom you translate it to "le prix de la liberté" (very commonly used phrasing in french), if it's providing for themself you can translate it literally by "le prix de l'indépendance".
Comment: Thank you for your answer! I appreciate the clarification on the subtle differences in context.


Why does the Falcon 9 use turbopumps as well as helium pressurisation system?

Question: Falcon 9 first stage use turbopumps as well as helium pressurisation system.
Isn't the turbopumps enough to pump in the propellants to the combustion chamber?
Comment: Using turbopumps without tank  pressurisation would destroy both the tank and the pump. The tank pressure must be higher than ambient pressure to avoid crumpeling. A too small pump input pressure would cause cavitation.
Comment: Generally a certain pressure is required at the inlets to prevent cavitation of the pumps.
Comment: @Organic Marble,  Wouldn't the RP1 and LOX self pressurise to allow safe start of the turbopumps?
Comment: Oxygen *can* autogenously pressurize from boiloff or from tapping off heated LOX from the engine, but RP1 can't and needs an inert pressurant.
Answer: Pumps are great at creating positive pressure, hundreds of bars. But with tank at ~1 bar, atmospheric pressure, they can only create a grand total of 1 bar of suction - can't go more vacuum than vacuum, can't create a negative density, can only go from original to zero - and 1 bar of pressure is a pretty meager amount, when this kind of flows is involved. And without a gas to replace the liquid already pumped out, the pressure would be dropping even more.
And not only does it limit the supply - As demand exceeds supply, vacuum bubbles start forming - aka cavitation, areas where new liquid can't flow in fast enough. And cavitation is bad. Liquids are very badly compressible, and such a vacuum bubble, when the flow catches up, vanishes completely as the liquids on its sides meet up - and does so quite violently. It causes a pressure wave that travels through the liquid at speed of sound (in that liquid) and can cause trouble wherever it hits, be it sending tank walls into vibration that can damage bearings, be it impacting turbine blades, bending them, or facilitating more cavitation where conditions were "almost but not quite there" and multiplying itself - never mind pump blades churning vacuum don't do anything useful, a lot of energy wasted on spinning pointlessly moving way less liquid than they could - if that liquid was there.
So you need that extra pressure to overcome the resistance of the plumbing, valves, acceleration of the liquid entering the pipes etc, so that the turbopumps never cause cavitation.
Comment: In other contexts one would call this approach *push-pull*, as the over-pressure from the helium pushes the liquid out of the tank, and the suction from the pumps pulls the liquid towards the pumps. No idea whether this is used in this context, however, I find *push-pull* describes the result rather good.
Comment: @DohnJoe In pumps, a positive pressure at the inlet is called 'hydraulic head' and is typically expressed in meters (although probably not in space applications), and it is implicitly understood that a higher head is better (think of a submersible pump). I would personally associate push-pull with bidirectionality (like in a push-pull amplifier), not with increasing hydraulic head.
Answer:
In a turbopump feed system it is still necessary to pressurize the tanks slightly (10 to 50 lb/in2) in order to prevent pump cavitation.

Rocket Propulsion Elements, Sutton, 4th edition, p. 223
Different vehicles have used stored onboard gas (typically helium) or autogenous propellants to provide this pressurization.
Further reading:

Why does the Falcon 9 require a helium pressurization system?
Why does the 2nd stage of Falcon 9 need compressed He tanks?
Is presssuized gas absent in a turbopump-driven rocket engines?
Why Use Helium?
Disposition of the Oxidizer Tank in Rockets with Autogenous Pressurization
How does tank pressurization work?
Comment: Crazy how a scientific/engineering book from 2001 using lb/in^2
Comment: @Michael Rocket science is a bit of a misnomer. A better term is "rocket engineering". Use of customary units remains very widespread to this day amongst engineers in the US. I have worked for / consulted for multiple new space endeavors who explicitly start with the goal of using metric throughout rather than customary units. While I laud that goal, it never seems to work, at least not completely.
Comment: @Michael Imperial units were [still in use in 1998](https://en.wikipedia.org/wiki/Mars_Climate_Orbiter).  NASA institutionally may have learnt from that, but individual engineers are likely more resistant to change.
Comment: @Michael my copy is from the 1970s.
Comment: @Graham the shuttle program ended in 2011, and was all English units (not Imperial).


Trick or tool to help line up 48 splined crank arms

Question: Besides eyeballing it and comparing the line to the seat tube, are there any tricks to getting 48 splined crank arms perfectly aligned? I must have spent a solid 15 minutes looking at them from every angle until I was satisfied.
Comment: Use a short bubble level about 12 inches long. Put the cranks level and compare the two.
Answer: If your bearings are decent, just take the non-drive pedal off and let the pedal weight pull the other side down, or slowly let it fall from slightly off center. This is how I could tell with my Bullseye cranks, besides hopping on and trying to pedal it. If that doesn't work then I'd try tying a heavy weight or looping a paint can around one of the pedals close to the crank.
You're looking for a 7.5 degree distance, so on 185mm cranks that's 24mm or nearly and inch of diference between splines. Weighting the opposite side enough should make it clear. I then took some nail polish and marked both the crank and axle so I didn't have to play this game again.
Comment: good idea, you made me look up law of cosine to get the distance for 175mm cranks. lol, it's 22.89mm...I guess it's pretty noticeable if you are off.
Comment: You're going to hate me if you actually used the law of cosines for this comment, but you're making it more complicated than it needs to be. The hypotenuse is 175mm, and you're looking for the opposite length of the right triangle made from the angle, so it's just 175 * sin (360 / 48) in degrees. You also REALLY notice if you try to pedal like that.
Comment: lol, I knew there had to be simpler way :) my geometry is extremely rusty, so I used first thing I found on google.
Comment: Im gonna give you the check for pointing out how obvious it'd be off. If I had realized this, I wouldn't have been so worried about getting it perfect.
Answer: Some BMX cranks are keyed, so that they will fit only one way. If yours is not keyed, then, no, there is no better way to line it up than to do it by eye.
If you want to double check it, take a plumb bob, and place it across the center of the pedal threads on one crank. Turn the crank until the string lines up with the other pedals' thread center.
If the string follows the center of the crank arms, you are lined up.
As pointed out by @Ehryk, the difference is pretty visually noticeable. Probably not worth all the effort involved here, since you see an almost 1 inch variation by eye easily.
Comment: thanks, I was unsuccessfully trying to use a drywall T-square at one point. Will try the plumb bob.
Answer: Besides the given suggestion(s), another possibility (although a bit overkill) could be to take a picture from afar (5m+), with the camera aligned to the bottom bracket axis, and analyze the alignment on the zoomed image, via eyeballing or some drawing/viewing program.
Answer: I would try using trial-and-error.  First I'd attach one crank arm and get the nut finger tight.  Then I'd put the second on where I thought it should be, take it off and put it on one tooth away from that, then try again in the other direction.  I can't help but imagine that (as Ehryk mentioned) when it's wrong, it would be very obviously wrong.
Once I was satisfied with that, I'd line up one of the arms with the seat post or the down tube, take a few steps back, and eyeball it.


Can String be a subtype of Character in a programming language?

Question: Could a programming language be designed so that there is an inheritance relationship between string and character (both of which are native types), such that the inheritance alone resolves the use of an arbitrary binary operator between the two types: <string> @ <character>; coercion and overloading cannot be used. My intuition is that string would be a subtype of character because a string may be composed of characters, and all basic methods defined for a character work with a string. As a subtype, string could have very specific functionaity such as a length method or attribute. On the other hand, I can see how it might make sense that string is the supertype and character is the subtype. Namely, a character could be thought of as a string of length 1. Which interpretation is correct, or at least which interpretation is more sound?
Comment: Note that LSP easily shows that a character (or any fixed-length string) is not a subtype of a mutable arbitrary-length string, because they can't support any operations that change the string length.  But immutable strings don't support those problematic operations.  On the other hand, how do you implement the character operations for strings such that they succeed on a string of length zero?
Comment: @BenVoigt yes that is what I am confused about. This is actually a question in the practice section in my textbook. My professor told me the answer should be clear... If inheritance is strictly defined as an `is a` relationship, then I do not see how a string could be a character
Answer: Character and String are conceptually very, very different. Google for "inheritance vs. composition" - you seem to think that Character and String should be connected via inheritance, but in reality a String is composed of 0, 1 or more Characters.
And to throw a spanner in the works: Strings are often large, and String operations must be very efficient. Therefore, even though conceptually a String is an array of Characters, it will not be implemented as a sequence of objects, but as an array of somehow simpler elements, for example UTF-16 codes.
And then you can think about how to implement Character efficiently if you use Unicode and an emoji character can easily be made up of a dozen Unicode code points - but the huge majority of Characters doesn't need that complexity, and you want an implementation that is space efficient and fast.
Comment: Thank you for the great answer, this is actually from a practice question in my textbook. When I asked my professor, he told me the answer should be clear if string and character are clearly defined. However, an inheritance should be an `is a` relationship, so clearly a string cannot be a character, but a string defines additional methods not defined for a character.
Answer:
Subtyping is conceptually very different from inheritance.
Subtyping refers to shared interfaces; $\tau$ is a subtype of $\tau'$, i.e. $\tau <: \tau'$, then all expressions of type $\tau$ could be used when  one of type $\tau'$ is expected. Inheritance refers to the reuse of implementation; if class A inherits class B then A reuses the implementation of B. A doesn't have to be a subtype of B. For example, a "Stack" class might inherit from and reuse the implementation of a "List" class, but it "Stack" can't be a subtype of "List".
For more on subtyping and inheritance, see, e.g., Turbak, Gifford and Sheldon, Design Concepts in Programming Languages, pp. 701-25.
"Character" can't be a subtype of "String" if the implementation is to be useful
Sure you could design a language with "Character" as the subtype of "String". However, how useful would this design be? It is easy to find a function that you couldn't implement under this design, e.g. convert a character to a hex code based on its encoding; a "String" wouldn't be valid input to this function.
But you are be right the other way. A "Character" could be thought of as a "String" of length 1; but that would imply $\mathtt{Character} <: \mathtt{String}$, not the other way. This is probably not the best programming language design decision you could make, but it'd work.


How long does a Red Flag stay in Airport system

Question: We are Americans and travel to Bkk about once a year and a couple of years ago my son was flagged for frequent visits even though it isn't the case.  He was told that he needs to get a visa next time.  So the last 2 times he got a visa from the Embassy.  He hasn't been in BKK for about 1.5 years now.  My question is, does he need to get a visa for our trip next week or will he be able to get his visa exempt stamp at the airport?
Comment: Have you asked the embassy?
Comment: Although @dbkk answer makes a good point, can you edit your answer to demonstrate the previous 2-3 year entry/exit history to any port of Thailand for your son?  We need a complete history to maximize giving you the best answer.  This should be recorded in the passport used.
Answer: Thai immigration rules are not clearly defined or properly published and often in flux. There's plenty of speculation on the internet, but you won't be able to get a clear and reliable answer on this, even if you personally ask an immigration official. Similarly, embassy/consulate staff would be next-to-useless, since they're under a different ministry than immigration at the borders, and can't even access the immigration database. What is clear is that over the last several years, Thai Immigration has taken a bit of a dislike of frequent visitors.
I would keep getting the tourist visa prior to any future trip -- it's a long way to risk a rejection at the airport. Note that in addition to applying in person, you can also get a tourist visa for Thailand by mail at any consulate.


How do you check or correct the FOH sound engineer?

Question: When you're on stage, how do you check the house sound when you have a sound engineer?  All you can hear are the monitors.
Comment: ...Trust his judgement?
Comment: I feel your pain. I've played at places where the sound 'engineer' was fiddling with his knobs all night, and wouldn't leave the mixing desk alone so our vocals were too loud one minute, too quiet the next. ugh.
Comment: Great question, I have seen examples of where the band sounded great to themselves through stage monitors, but the house mix was terrible and the audience experience was not so good.
Comment: The best I've done on this is to have friends in the audience who are musicians who I trust and ask for their opinion after the show. Based on a few of their opinions, plus my experience talking with the engineer and hearing the monitor mix, I form my own opinion of that engineer and file it away for future reference.
Answer: You can't.
Even if you get the sound guy to feed the FOH sound through the stage monitors (or your IEM)
it won't give an accurate representation of the FOH sound, there are simply too many variables.
If you want to check FOH sound you need to walk off the stage during sound check to hear it.
A long lead or a wireless pack will allow this. Be aware the number of people in the room dramatically changes the acoustics so doing this during sound check (empty room) may not always give a good representation of the FOH sound the crowd will hear later.
Some sound guys "set and forget" to a happy medium and some will adjust as the room fills up to account for the change in acoustics.
Your best bet is to only use reputable sound guys or find a sound guy you like to work with and use them regularly. Theres nothing worse than turning up to gig where "the sound guy is provided" only to find the "sound guy" is the bar man.
(I don't use the word "engineer" as your average sound guy has less in common with an audio engineer than a carpenter has in common with a structural engineer)
Answer: There's seven billion people on this planet: pick one you trust and ask them to go to the back of the house for a sound check.  Fans are great for this; they're just so honored to be asked, and they have some idea of what your music is supposed to sound like.  Or if there's more than one act going on, you can often ask the musicians in another band to help with your check, and you can reciprocate.
The traditional way of handling this is to trust the sound engineer.  That works fine -- if it's a good sound engineer.  Otherwise, not so fine.
You may want to be a bit discreet about this all as it constitutes checking up on the sound engineer's work.  They may not appreciate the implicit vote of no confidence in asking someone else to check the sound.
Comment: In my experience, fans tend to give horrible advice. Most either say everything's fine regardless of what a complete mess the sound is, or always say the vocals are too quiet when the problem lies somewhere completely different that just happens to make the voice incomprehensible. Of course, you can't generalise this – there will usually be some guys that know a good bit about sound, but you should know whom to ask. But +1 for the other paragraphs. When the engineer is bad then loud criticism from stage usually won't help much either, better let them concentrate as good as they can.
Comment: Agreed - although a good sound engineer should accept that the band may want to hear their own sound no matter how much they trust FOH.
Answer: Where possible we like to use our own sound engineer - he knows what we want to sound like and knows our foibles with kit, amps etc. Where we can't use our own engineer, our two favourite techniques:

a long lead or wireless kit. I walk right out round the arena/pub/field/wherever and see  how a couple of our key tracks sound (we have two examples we use as they have quite different characteristics) and guide the desk based on what I hear, and usually sound guys are good enough to retain that sound as the venue fills up (tweaking for the density of humans)
venues that record the desk. King Tut's in Glasgow is an excellent example of this. By default they record everything coming into the desk, and can play back any part of the sound check. This means the entire band can sit out front of house and listen to our overall sound - which can lead to some heated discussions over what should be adjusted, but is an excellent way to get agreement on the complete sound.
Comment: Regarding playback of the recorded sound from the desk: That can only be useful for quite large venues, as there is no sound from the stage?
Comment: It is useful anywhere that has a 'proper' PA, ie can replicate everything you were doing acoustically. On stage we are slightly odd, in that we have taken to connecting directly in to the desk where possible (all of us use pedals with pretty decent amp simulation so can just DI straight in), and using monitors only. This does away with the need for amps and cabs on stage and makes it very easy for us to tour.
Comment: Great idea on elimination of back line with DI and only use monitors.  But @MeaningfulUsername makes a good point as it relates to bands playing small venues with back line on stage.  Folks close to stage are going to get some bleed from the back line amps.
Comment: Are you from Glasgow, Dr Mayhem?
Comment: No, we're Edinburgh based, but we play more gigs in Glasgow as it is more of a rock city than Edinburgh.
Answer: Given that you can't be playing and have your ears at the back of the hall, your options appear to be ..

check it via headphones - I think this will sound unrepresentative though. Sound through headphones is pretty different to when you're partway toward the back of a room.
run to the back of the hall to check the sound while someone else plays your gear- this assumes they play/sing similarly to yourself, and isn't practical during the show (depends what kind of show though I guess!)
Ask someone whose ears you trust to stand at the back and either communicate with you or the sound engineer about how it sounds.

I play with a 3-piece rock band in pubs quite a lot, and we look after the sound ourselves. However we still need to check it.
During the sound check, before the gig starts I sing something and the bassist (with long lead) stands where the audience will be and listens to the balance, makes comment about anything too loud / quiet. I make adjustments.
Then he sings somethign and I do the same thing, twiddling mainly just volume differences or sometimes a bit of EQ.
This works really well but of course it's only useful for smaller venues where a guitar lead can reach so a spot in front of the band, but not too near.
Answer: You try to tune the sound engineer into "from a combination of direct sound and the monitors, please help us hear as accurately as possible what's going out front".  Then DON'T keep asking for "more me", if you turn up for a solo don't forget to turn down again afterwards...   It isn't ALL his fault!


Why was this questions closed?

Question: The question "How do I find "early adopters" for a constructed language?" was closed. Please see the comments below the question for additional information, but for further questions/answers/comments on related to if this question is on or off topic, please use this page on meta, not the page for the question itself.
Comment: blunders, the data you posted is not necessary here. It can be read clicking on the link. Rather, it would be better if you could concentrate on why you disagree with it being closed.
Comment: regardless to how the question could have, should have been copied, a closed question is at risk of deletion and that is true on any stack exchange site, so there is some merit to (over)copying the text when moving to meta.
Comment: @Alenanno: Not happy that I went to the effort to meet your request to ask on meta and so far you've not provided any additional feedback for why this question was closed as you promised to do.
Comment: [Done](http://meta.linguistics.stackexchange.com/a/364/111).
Comment: @Alenanno: You clearly stated comments to the close where a better fit for meta, I've ported the question, and deleted my comments, and would ask you due to, since it was you're request, not mine to move the topic here. My issues stand as stated above in the ported comments and you have not addressed them, and said you would if the matter was move it meta.
Comment: Yes but porting everything here is just **cluttering** the question and removes space to your request.
Comment: @Alenanno: No, it's cluttering up the question, not meta, and makes it possible to gather all related information on the matter at hand in one place. Leaving the meta related comments on the question itself is poor form, and it would also be poor form to just delete them and start from scratch in my opinion.
Comment: +1 @MatthewMartin: Agree, the question maybe deleted, and a link to a deleted question would provided no content.
Comment: It's not an action that deserves merit. If necessary, a moderator can recover the question for you.
Answer: Quoting myself from the above comments:

The underlying reason is probably that this is not part of the academic field of linguistics. And why is that? Because linguistics is about the way language works as a natural phenomenon, as perceived externally. So a constructed language is more about how an individual person would like to design an artistic project. That said, questions like why did Esperanto become more popular in x than in y? might be on topic, though perhaps they would be a better fit for History.SE. Questions about how do I find x? are only on topic if they ask for resources about linguistics.
Comment: So, are you saying that a collectively planned language would be a constructed language, and questions related to collective building of languages would be on topic, or am I reading to much into what you're saying?
Comment: @blunders: Umm I'm not sure, I'd have to see the question! But anything that is mainly about "how can/should be proceed in creating this language" would not be linguistics in my book, however interesting it is.
Comment: Okay, thought so, but wanted to make sure, thanks!
Answer: I'm going to take a stab at this question.
Conlang enthusiasts (and all three or four of the the conlang professionals) have a different standard of truth, different culture and a different audience from academic linguists.
The standard of truth and goodness in conlangs is closer to that for fiction writing than for science and science doesn't have much to say about what constitutes good fiction (or how to get fans for fiction).
The audience of conlang users is mostly hobbyists and for those hobbyists that are planning something big-- like a business, or political or social movement, they still haven't gotten past the hobby stage. [The sole exception being Esperanto]
With a different audience comes a different culture.  In the conlang world, there is a lot patting on the back and evaluation of conlangs moral, artistic merits, because conlangers are a bunch of artists trying to create something.
Conlangs and linguistics do cross path time to time, for example Esperanto is spoken by native speakers, so it is a natural language, too. Some linguists use fake model languages in experimental linguistics, e.g. having subjects learn a few words of a fake language and observing how the people answer questions about it.  These intersections are probably not big enough to warrant merging the conlang proposal and the linguistics SE for the reasons above.
I think the taxonomies that stack exchange uses to divide up human knowledge is imperfect, but they have a difficult task. SE alternative would be to allow all SE sites to become yahoo answer style sites, where everyone can ask anything, and from listening to the StackOverflow podcasts, it was a conscious decision by the sites founders to avoid any-thing-goes question sites.  The down side of this is that some questions (like on conlnags) have no place to be asked and have a really hard task of getting enough followers to start a stack exchange style Q & A site for conlangs.
In the meanwhile, there are conlang Shapado sites out there, and there is the SE conlang proposal.  Shapado is a stack exchange clone where you can ask questions today (but there isn't an audience) and the SE conlang proposal is ready to go live any decade now. Maybe Avatar 2 will bring enough people to the proposal to get it off the ground, we'll have to watch and see.
Comment: Point is that there's currently no better home for these types of questions on SE, that this SE is the most likely to be able to answer them, and that if SE conlang proposal reaches public-beta, they could easily be ported.
Comment: Also, I might note that this SE is in danger of being closed for good, ["Sites shutting down, what is our position?"](http://meta.linguistics.stackexchange.com/questions/326/sites-shutting-down-what-is-our-position), and that one of the suggested answers is to [expand the scope of the site](http://meta.linguistics.stackexchange.com/a/337/256).
Comment: @blunders, surely you're aware that there is a [Conlang proposal](http://area51.stackexchange.com/proposals/12409/planned-and-constructed-languages) in the commit phase over at Area 51? That's the place for constructed language questions to (eventually) go. Also, I doubt that adding conlang questions would help this site much if it were in serious danger of shutting down, as many pro linguists (not me, as I am also a conlanger) dislike conlangs and would be turned off by a site that included them.
Comment: @JSBᾶngs: Yes, I'm aware of the Conlang proposal, in fact, it's why I asked the question here, since it's still a proposal, I was looking an answer, and felt that this SE was the most likely to produce one. I agree with [Mark Beadles answer saying we should allow questions of this type](http://meta.linguistics.stackexchange.com/a/365/256), and further believe that we should support these questions until the proposal is public.
Comment: Matthew, what is your point then? Are you pro-allowing them or against and why?
Comment: @Alenanno: From Matthew's answer, "These intersections are probably not big enough to warrant merging the conlang proposal and the linguistics SE for the reasons above."
Comment: @Alenanno I'm biased. I'm pro-conlangs and pro-conlang questions, but I know that if there was a cocktail party with 50% linguists and 50% conlang enthusiasts, that there would probably be some culture clash and unproductive bickering. So for that reason, it makes some sense to have a separate site and aligns with (my understanding) of Stack Exchange's goals of homogeneous (by topic) sites and homogeneous audiences.. All that said, I really hope that someday there is a place to ask conlang questions in a SE format, and if it turned out to the the linguistics site, I wouldn't be sad about that.
Comment: @MatthewMartin Have you seen [this](http://meta.linguistics.stackexchange.com/questions/367/should-we-include-esperanto-in-our-scope)? :)
Answer: Questions about Constructed/Planned Languages have been deemed off topic since the Definition phase. I agree with that decision, because Linguistics is dedicated to natural languages evolution and not about the creation of artificial systems.
The site has some low visits, yes, but they're increasing and expanding the scope is not the right answer. What we need is to spread the site, make it so that more people know it and we'll have our visits. Expanding the scope is not the answer because our scope already covers all of the Linguistics fields, even the not "pure" ones. Your questions, as other previous ones, have been closed because of this policy, which wasn't clearly discussed in Meta (I think, haven't found the question), but that that went under discussion many times before now.
Concerning your claim about users not being forced to read the FAQ, well, it's true: you're not forced to read the FAQ. But then it shouldn't come as a surprise if your question gets closed as a result.
Moreover, I'd like to add that this is not me against you. I have no personal problems with you. I just took a decision as the mod that is here to enforce the rules.
Now that we're here, let me tell this too: if it wasn't off topic, your question would have been closed as not constructive. The close reason states:

This question is not a good fit to our Q&A format. We expect answers to generally involve facts, references, or specific expertise; this question will likely solicit opinion, debate, arguments, polling, or extended discussion.

This is what you're doing: you're asking for opinions. It's not the quality questions we could get for this site. I'm sure you could get better questions than this one.
Comment: Yes, I know it's not me against you, and that I might come across as being such, but I'm only attempting to be direct, address the issue, and move on. Just because an item is listed in the FAQs as off-topic, or for that matter in some historic document, does not mean in my opinion that revisiting the topical scope of a domain is unwarranted. The fact is that even natural language are constructed over time, and some natural languages have even been constructed within the past 100 years.
Comment: As for being 'not constructive', you're inferring that I wanted opinion, which I don't, I want real research, based on quantitative data.
Comment: @blunders "How do I find..." is quite an ambiguous type of question. What type of answers does it suggest? You didn't write "tell me your opinion", but that's what this wording asks for. It would be great for a discussion, but not so great for a SE site.
Comment: I personally am not a big fan of conlangs. However, they do use elements from artificial languages in some language acquisition studies, esp. in connectionist psycholinguistics. Once again, I don't think highly of that kind of research but that's my personal opinion.
Answer: I am a dedicated conlanger.  That's why I'm on this list.   But I must agree that conlanging should be considered off-topic on the Linguistics Stack Exchange.
It is so very tiresome to hear people ask "Why make up languages when you could study real ones?"  This is like asking a painter "Why paint imaginary meadows when you could get a degree in biology and study the ecology of real meadows?"  I really shouldn't have to explain to thinking people that giving form to my whimsical fantasies differs greatly from scientific investigation.
My conlanging has been inestimably enriched by an acquaintance with linguistics.  If my hobby were drawing monsters, I would see zoology in the same favorable light.  But zoology does not include the study of dragons, and linguistics does not include the study of conlangs.  So on this list, let's "keep it real," so to speak.
Comment: @Alenanno: **Wrong, please be logical, creating new plants, virus, animals, etc. is not science fiction, nor is constructing languages.**
Comment: @blunders I [did it](http://meta.linguistics.stackexchange.com/q/367/111).
Comment: +1 Good comparisons, I think they bring a good perspective on the matter. :)
Comment: @blunders Please pull yourself out of your perspective about your question. I understand you don't like your question to be closed, nobody does, but make my job easier: try to be objective. Do you really think your question is within Linguistics? You don't need to answer me, answer yourself.
Comment: @Alenanno: Your response requesting I be objective, is not a response to my proof/response that constructing languages is not science fiction. As for being objective, I am, SE goal is to answer questions, and you're saying linguist are unable to answer these questions, and I disagree.
Comment: @blunders I'm not saying linguists are unable to answer, rather that it's not within their studies and/or area of expertise/interest.
Comment: @Alenanno: An answer is better than no answer, and there's nothing wrong with being flexible, or learning to think about a subject from a new point of view; in fact, in my opinion, that's the fastest way to learn.
Comment: @blunders Probably, but on SEs there are rules. The site must be about that topic, outside of it, nothing is allowed (unless you can cleverly word your question so that it also answers your off topic question :) ...)
Comment: @Alenanno: I'm aware it would be easier to be clever, but that does not change the fact that I believe a topic that linguist are able to answer is ontopic.
Comment: @Alenanno: Fine, you requested I be clever, [so I've made an attempt to be clever](http://linguistics.stackexchange.com/questions/1912/how-did-esperanto-find-early-adopters-for-the-language), please review the update, delete your now offtopic comments on the question, reopen the question, and if the question is still not on topic, please comment on the question itself. Thanks.
Comment: @Alenanno: From you, "If there is a constructed languages with native speakers, then we could think of allowing it." - I've updated the answer, and guessing you've seen the update too. Is there a reason you're not replying?
Comment: @blunders I'm not here 24/7, I also have a life. :P Anyway, I'm not the one who decides, I'm not the emperor of this site. If you want Esperanto to be allowed, I think it'd be best to have a wide support from the community to see it's wanted, otherwise no. So I suggest two things: **(1)**, you make a Meta question (I'll help you with it if you need help), and **(2)**: we talk about it in our [next (first) chat meeting](http://meta.linguistics.stackexchange.com/q/351/111).
Comment: +1 @Alenanno: Thanks, one thing I might note is that in my opinion it should be clear to voters on that page that only upvote will be counted, otherwise people may not realize the need to vote twice to insure their votes count, or are not undone by users voting twice.
Comment: @blunders Until now, it received only upvotes, I wouldn't worry about that too much! :)
Comment: @Alenanno: Okay, my rep is too low on this SE to see the voting breakdowns. Just thought I'd point it out, since I realized it would not be fair to vote twice when I went to vote. :)
Comment: @blunders I considered that. I'll consider the upvotes only I think.
Answer: At times like these I wonder if we shouldn't consider expanding our scope to include conlangs.
Stackexchanges have been shut down recently and our own numbers aren't that great. Meanwhile, the Conlang proposal is languishing at 29% in Commitment phase.
I know people want to not "clutter" the site with the possibility of many less-than-professional questions, and I tend that way myself. But I wonder if it wouldn't be better to expand and keep alive rather than remain closed and wither. "We must all stand together, or assuredly we shall all hang separately"?
Comment: +1 @Mark Beadles: Agree, the goal of SE is to answer questions, and I don't believe that allowing questions of this type will result in other questions not being answered, in fact, I believe the opposite is more likely, that more questions will be asked and answered within the existing domain as a result of expanding the topical scope of a domain. Further, there is no reason that the Conlang proposal need not go on, or that if it reaches a public-beta that the questions could not be ported.

Why was this questions closed?


What does 波 mean at the end of a sentence?

Question: Here are some examples where I saw 波 at the end of a sentence :
Comment: That character used to be a phonogram (man'yōgana) representation of the sound わ, maybe there's some fad or something to write the emphatic particle *wa* with it?
Comment: do you have links to these posts in context?
Answer: You are asking for a meaning, but really it doesn't "mean" anything in and of itself. This is an example of someone having fun with the language. The intention is probably to make it sound cute. There are many instances of this such as ふなっしー, the "pear fairy" mascot for 千葉県船橋市{ちばけんふなばしし}, which is famous for its pears.
Here is an excerpt from the English Wikipedia about "Funassyi"

Generally, Japanese local mascot characters, known as Yuru-kyara (ゆるキャラ laid-back character) or gotōchi-kyara (ご当地キャラ local character), move slowly and do not speak. Instead, they are usually accompanied by an attendant who speaks for them. Funassyi, however, always speaks for itself. It also often shrieks, jumps, dances and makes violent movements like headbanging. When it speaks, it usually ends its sentences with "nassyi" (~なっしー ~nasshī) which sounds like the Japanese word for "pear" (梨 nashi).

So, as it says, ふなっしー ends its sentences with なっしー, saying things like

今年も神戸で会いましょうなっしー!

in an ad for an event in Kobe, which means

Let's meet in Kobe this year too nasshi!

Getting back to the original examples, without seeing the blog(?) myself I can only guess, but I have mostly seen this kind of thing with aspiring idols. They pick a theme or gimmick and often shape how they speak around that. Perhaps this person has the kanji 波 in their name or something like that. I can pretty much guarantee that it is read なみ~ but I only have my experience to go on and can't prove it.
Grammatically speaking, these kinds of word/sentence endings can take the place of です, as would fit the examples you posted, but as you can see with the ふなっしー example, that doesn't always hold true. It's just a decorative way to end a sentence that fits the character the speaker is trying to portray.


cleos set contract error Unexpected char '60' in ""

Question: Two weeks ago I tried to use cleos subcommands and everything worked fine. I could set contract to the accounts I created using my own smart contract code. Now whenever I tried set contract or create account, it kept giving this error. I tried changing the config files and rebuilding eos but the program still doesn't seem to work. What can I do here?
Comment: Hi Tim, I remember running into this error as well a couple of weeks ago, I **think** it was related to the an earlier version of cleos (pre 1.0.2). Which version are you running? I would suggest getting the latest, rebuilding, and make sure you do `sudo make install` from the build directory once the build is complete.
Comment: @Vlad hey Vlad, how would you check the version of cleos? I ran sudo make install and restarted nodeos but still give the same error, unfortunately.
Comment: From the error, it seems that the argument value is not passed. Passed string is "". This seems to be a similar problem - https://github.com/EOSIO/eos/issues/3782. Look at nodeos in the same way.
Answer: The reason you're getting this error is because you're using the wrong flags to generate the ".abi" and ".wast" files.
Ensure you are using the "-g" flag to generate the ".abi" file and the "-o" flag to generate the ".wast" or ".wasm".
The commands you should run are:
<code>
eosiocpp -o AccountPhoto.wast AccountPhoto.cpp
eosiocpp -g AccountPhoto.abi AccountPhoto.cpp
</code>
Also, you may want to consider switching to the EOSIO.CDT package, which now uses eosio-cpp. The abi and wasm files are also generated in one command (instead of two).