Now that I've asked a question - how do I find it again, if there aren't any replies yet?

Question: I don't see a link to click for "Subscribed" questions.  I will be leaving this tab open in the browser and refresh it in order to be able to find the question again, and see if there are any answers.
Comment: Please don't be bothered by someone who edits your post (see [this page](http://stackoverflow.com/help/editing)). He's just trying to be helpful by improving the question. That's just the way things work over here ;-)
Comment: @Infinite Recursion - you massively edited this question?  That's just unnecessary to do to me to make me feel bad over nothing.  It was understand able enough for 1) you to figure it out and 2) someone to reply with what turned out to be an answer before you edited.  I'm bothered by this!!!  I wish you'd taken a moment to answer it too.
Comment: I had used replies yet because it's not an answer until it works.  Though I will agree that answer is probably easier for a passerby to figure out quickly.
Comment: Thanks Lucas -- he could edit something that wasn't understandable.  For me, it, it makes me feel badly to have my words changed by someone else for what doesn't seem like an obvious reason...oh well.
Comment: Really  curious why -3 on this question.  It offended people that I asked this?? Really?  They didn't post any complaints.  This part of stack overflow with the option of people endless niggling at you, and even attacking under guise of the rules - is one aspect of SO that I don't care for.  It makes me nerveous every time I come near or post -- "what trivial will I encounter today?"  Not cool stuff, in my view.
Comment: It was downvoted because, well, the answer seems obvious for most people here ;-) Also, voting on meta doesn't count towards rep. Note that if you disagree with an edit, you can rollback it anytime, but people edit other people's posts all the time over here, so unless you feel strongly about an edit in particular, just let it go.
Comment: Lucas - thanks for the explanation.  I find it odd, but it helps to know the over context of how this works.
Comment: As for the answer being too obvious -- in my book that's an extremely rude reason to down vote someone.  I come from tradition of asking questions and it's bad form to make someone feel bad for asking something.  Obviously it the answer wasn't obvious.  I couldn't find the answer --- and I did later see someone else post a very similar question.  Oh well.  If people want to spend their time downvoting a question for being obvious to them, that's what's so in their life.
Answer: All the (non deleted) questions that you asked are listed on your profile.
Your meta profile is at https://meta.stackoverflow.com/users/4060469/curls?tab=questions.
And your main site profile is at https://stackoverflow.com/users/4060469/curls?tab=questions
That link can be found by clicking on your avatar and reputation at the top, centre of any page whilst logged in (or your username on any previous post), selecting "activity" then "Questions".
Recent deleted questions, if any, can also be seen (by you only) by clicking the corresponding link on that page.
NB: To see activity across Stack Exchanges per your comment you can look at your network profile. Linked from any individual site profile.
In your case the link is to https://stackexchange.com/users/5057815/curls?tab=activity
Comment: @curls if you are logged in you should see your avatar and reputation at the top, centre. Click on that and it takes you to your profile. Reason for mentioning deleted questions was just to be comprehensive about what is shown there.
Comment: Thanks.   My name's not at the top of the page.   I'm not sure why you are focused on deleted questions.  I'm not complaining that my questions  disappeared.  My ability to navigate the site is missing.  I can see a list of the forum questions and nothing at the top of the page that would lead anywhere?
Comment: I see.  It's the picture, not my name that's at the top.  And it only goes to questions for the particular stack I'm on.  I guess I have to dig on the stuff on the top left if I want to find the other stacks I was in.  But now I see how to get to my name... and from there to questions... and from there to replies.


How much has Earth warmed since preindustrial times, after all?

Question: Call it hair splitting, if you want, but I see at least three numbers in the latest IPCC report (e.g. on pages 7-51–7-52). The first one, "the total human forced GSAT change from 1750–2019", is 1.29°C. The second one, "the total (anthropogenic plus natural) emulated GSAT between 1850–1900 and 2010–2019", is 1.14°C. The third one, "the assessed GSAT", is 1.06°C. Suppose, the second one is a simulation and the third one is an observation (or so I understood). But why is the first estimate considerably higher than the second one even though the former doesn't include small natural warming, I take it? Keep in mind, 1750 and 1850 are almost the same baselines and differ by a measly 0.1°C so it doesn't explain the discrepancy. I'm not a science skeptic, by the way
Comment: Have you thoroughly studied the report? What does it say on the discrepancies?
Comment: @eric what do you mean?
Comment: You left out ranges. The 1.29 °C value, for example has a "high confidence" range of 1.00 to 1.65 °C.
Comment: @davidhammen but it's the best estimate that counts, isn't it? Besides, those are three separate numbers still. How do they differ? Why do they differ?
Comment: I imagine it depends on which stretch of years you're referring to--starting and ending dates--and also which set of observations you use. Hadley CRUTEM uses 1850-present, for example, while NASA GISS and NOAA start from 1880. Before that you have to use proxies like ice cores. You might also get a different answer by choosing two years as endpoints, as opposed to doing a linear regression on all the points and then using the estimated figures AT the endpoints. The latter is the way I'd do it.
Comment: @SergeyZolotarev if three different metrics get exactly the same number in science, it probably means someone is cheating. the numbers should vary since you are talking about very different means of measurement and calculation.
Answer: Some of the relevant AR6 headline values are:

+1.09 °C = Observed GMST and GSAT change between the periods 1850-1900 and 2011-2020

+1.06 °C = Observed GMST and GSAT change between the Chapter 7 attribution assessment periods 1850-1900 and 2010-2019

+1.14 °C = Emulated GSAT change between the Chapter 7 attribution assessment periods 1850-1900 and 2010-2019

+1.29 °C = Emulated GSAT change between end points 1750 and 2019, attributed to anthropogenic forcings

The +1.06 °C and +1.09 °C values are the same observed estimates of temperature change, it's just that the latter covers the most recent "current" period that was available at the time the report was being written.  Yes, the 0.03 °C difference comes from only one year of difference in the meaning periods, but that just reflects the effect of interannual variability on 10-year means.  The +1.06 °C value is only really included in the report for comparison with the work in Chapter 7.
The +1.06 °C and +1.14 °C values are two different estimates of the same GSAT metric.  They're not independent estimates because the latter is constrained by the GSAT observations, as well as other observations and models.  When you consider their uncertainty bounds, these estimates are consistent with each other, but, as noted in Chapter 7 p7-52:

As the emulated response attempts to constrain to multiple lines of evidence (Supplementary Material 7.SM.2), only one of which is GSAT, they should not necessarily be expected to exactly agree.

The GSAT observations tell us what happened, but they don't tell us why it happened: how much does each forcing agent contribute to the record?  In theory we could estimate these contributions by running full ESMs many many times, covering uncertainty in the forcing agents, perhaps also constrained by observations and their uncertainties, in an attempt to see the signals through the noise of internal variability.  But in practice, it's just not computationally possible to do that, which is where the emulators come in.

Cross-Chapter Box 7.1
Climate model emulators are simple physically-based models that are used to approximate large-scale climate responses of complex Earth System Models (ESMs). Due to their low computational cost they can populate or span wide uncertainty ranges that ESMs cannot. They need to be calibrated to do this and, once calibrated, they can aid inter-ESM comparisons and act as ESM extrapolation tools to reflect and combine knowledge from ESMs and many other lines of evidence.

The emulators don't (and don't attempt to) capture the full, noisy temperature record including interannual variability.  Think of them as emulating the underlying forced response of temperature without the obscuring effects of noise.
The difference between emulated values +1.14 °C and +1.29 °C is a mixture of several things: the 1750 versus 1850-1900 baselines (about 0.1 °C), the non-anthropogenic forcings (about -0.02 °C), and using end points rather than end periods (about 0.2 °C).  Note that just looking at the end points is normally not recommended in observations and ESMs because a lot of the difference will be internal variability, but that's not really a problem in these smooth emulations.  You just have to be careful what you do with them, i.e., what other values you're comparing them to.
So, the bottom line is that the best estimate of the warming that has been expressed by the system to date is +1.09 [0.95 to 1.20] °C.  From the AR6 SPM headline statements (my emphasis):

A.1.2 Each of the last four decades has been successively warmer than any decade that preceded it since 1850. Global surface temperature8 in the first two decades of the 21st century (2001-2020) was 0.99 [0.84-1.10] °C higher than 1850-1900. Global surface temperature was 1.09 [0.95 to 1.20] °C higher in 2011–2020 than 1850–1900, with larger increases over land (1.59 [1.34 to 1.83] °C) than over the ocean (0.88 [0.68 to 1.01] °C). The estimated increase in global surface temperature since AR5 is principally due to further warming since 2003–2012 (+0.19 [0.16 to 0.22] °C). Additionally, methodological advances and new datasets contributed approximately 0.1ºC to the updated estimate of warming in AR6.
Answer: There has been a component of natural cooling over that period - not warming. 1.14C is the modeled  amount of warming overall, which comes from 1.29C of anthropogenic, less 0.15 of natural cooling. There appears about 0.8C of difference between modeled and assessed from actual temperature data - which is almost certainly within the expected range of uncertainty (which were not provided here).
It would be more remarkable for modeling and temperature data to work out exactly the same than being a bit different, but within the ranges of uncertainty.
Answer: About 1 degree Celsius since the 1850s. That's up from a another one since the 1600's. Earth's temperature rose about 1.5- degrees since the 1700's.

If you want a good guess, use the CET since 1659. NOTE the temperature curve, failed to obey the CO2 curve.
Average temperatures are hard to come by largely because corrupted data from temperature data from weather stations placed in poor locations..... Subtract Urban heat island effect it spits in eye of climate alarmists. And many temp sensors are in cities, thou cities only make up 2.7% landscape they have vast majority of data sets.
Outliers often Always offset averages, Urban heat islands affect, even at nighttime temps; An asphalt parking lot can store a days worth of solar energy and heat air an added 10 degrees in daytime, 2-5 degrees at night. Contaminated temperature data come from temperature sensors and weather stations in parking lots and urban building zones.
Comment: Downvoted. Graph is not global average and location appears chosen because it has less temperature rise than the global average. The blanket disparagement of temperature records as poor data dismisses the professional efforts made to "homogenize" - ie account for known distorting factors including heat island effect and, without any evidence suggests global average warming is a consequence of poor data. The pics, like the graph are cherry picked.


How to transmit DTMF signal to Arduino

Question: I'm trying to read an incoming DTMF signal through the A0 input pin. I want to do this programmatically and not with the MT8870 module. This library (https://github.com/Adrianotiger/phoneDTMF) is supposed to do just that but I can't figure out how to connect my incoming DTMF signal to Arduino's A0 pin to receive the signal. Basically, my laptop produces the DTMF signal and I want to attach the line out, which is two wires, the positive and ground, to Arduino.  None of the configurations I've tried work.  I've tried to attach the positive to A0 and the ground to ground, but A0 doesn't seem to be detecting anything.  I also don't want to use a microphone on the A0 pin to detect the DTMF. A simple Fritzing type diagram showing how to connect the incoming DTMF signal to A0 would be helpful. Thanks.
Comment: Not an expert on DTMF, but have you made sure to get the signal range into the 0 to 5V range of the Arduino? Line Out is symmetrical around ground and I think the peak to peak range might also be wrong. The linked library also has a circuit for adjusting the range, though it is designed for the landline voltage levels
Comment: I was thinking of trying to connect an LM386 amplifier to boost the incoming signal, but I still don't know how to configure the two wires to Arduino.
Answer: Your problem is that you think there's a "positive" signal. In audio there isn't a "positive" signal, there is just a signal that swings around 0V.
You have to convert said signal to a "positive" signal by adding a DC offset to it.
The simplest way is with one capacitor and two resistors:

simulate this circuit – Schematic created using CircuitLab
That schematic will remove any DC offset that your laptop may add ("AC couple") and then add a 2.5V DC offset of your own to the signal.  The audio signal will then be alternating around 2.5V.
You may need to boost the audio signal's volume with an op-amp (note: do not use a "power" amplifier like the LM386, it is not suitable; use an op-amp) to increase the sensitivity of the input.  You could do this with a simple inverting amplifier arrangement with the DC offset being injected into the non-inverting input:

simulate this circuit
Here the gain of the amplifier is the ratio between R3 and R4 - in this case a 10:22 ratio (or a 2.2x gain).
From a software point of view you now remove 512 from each analog read value to give you a range of +/-511 for your sampled values. You then probably (maybe with the library you link to) take a block of samples at a defined frequency and perform an FFT analysis to find what dominant frequency components are present.
Comment: I set up the first schematic, and was able to detect the DTFM tones.  Thanks! The only problem, though, is that the program seems to be detect the wrong tone.  Using the tone generator here, https://onlinetonegenerator.com/dtmf.html, whatever button I push, the program detects the button down one row and to the right one column. Eg. I push 1 and 5 is detected. Or I push 5 and 9 is detected. I will post a question about this because it seems to be a software problem.

How to transmit DTMF signal to Arduino


Bike rests on brake cable while racked

Question: I bought a new bike and when I put it on my bike rack in my garage the arm of the rack sits on the rear brake cable, putting some tension on the cable. Could this cause brake problems and if so what can I do to mitigate this?
Comment: A photo would help. I'd be inclined to modify the rack by adding padding to a block so the bike sits properly.
Comment: It's not a good thing to have going on, long-term.
Comment: Can you route the brake cable differently?  Or modify your rack to put a channel where that cable is?  What kind of brake problems are you experiencing ?
Answer:
Could this cause me to have brake problems

Yes: The weight of your bike will pinch the cable and slowly cause the cable to lose its structural integrity and become damaged: They are designed to take stress along them (tensile strength), not laterally (shear strength)... hence how they can withstand huge amounts of force from braking yet can easily be cut with cable cutters by most healthy people.

what can I do to mitigate this?

Don't pinch the brake/shifter cables between anything. If your rack pinches them, adjust the rack or get a new one.
Comment: I disagree -  consider the pressure and deformation of the inner cable where it is held to the brake by the pinch-bolt. Much much more pressure than your bike's weight will ever put on the inner wire by pressing on bare metal. Even if you were mounted-riding on your bike while it was on the rack, the pressure on that inner cable would be far less than under that pinch bolt.  Instead, simply pad the rack to spread any load-problem solved.
Answer: Thanks everyone for the help.  After doing some investigation I actually came up with a pretty simple solution.  Simply turning the bike around and facing it the other way made it sit so it no longer pinched the cable.
Comment: This answer does not answer if the bike-resting on cable is bad or not. That's why I prefer the other answer.
Comment: It seems more like a solution to the problem, instead of an answer to the question.
Comment: @EricSmekens Isn't that the same thing? ;)
Comment: Now that's good work.  You should mark this as the Accepted Answer by clicking the tick/check box to the left.

Bike rests on brake cable while racked


How is this classical "paradox" resolved in electromagnetism?

Question: A magnet and a coil move relative to each other. In the frame of reference of the magnet, there is a magnetic field and consequently a force acting on the charges in the coil according to the Lorentz force $F=qv\times B$ but there is no net electric field. In the frame of reference of the coil, there is a magnetic field and also an electric field, induced by the magnet, $E'$ that moves the charges in the coil, producing a current. But, in the first case no work is done on the charges, since the force is perpendicular to the velocity. In the second case, the force $qE'$ does work on the charges. How is this "paradox" resolved in classical electromagnetism?
Comment: [Here](http://en.wikipedia.org/wiki/Moving_magnet_and_conductor_problem) is a nice explanation.
Comment: This seems like hw.  Look up Lorentz transformations... The E in your one frame is $v\times B$ in the other.
Comment: And you're probably not moving relativistically, so $\gamma\approx 1$.
Answer: When the magnet is moving, the electric field of the magnet is doing the work, pushing the current carriers around the wire. When the magnet is still and the wire is moving, the magnetic field produces a force in the current carriers, but this force does no work, it is the constraint force that keeps the electrons in the wire that is doing the work. The paradox is resolved by noting the the wire is moving, so the constraint is not time-independent.
The constraint force is perpendicular to the surface of the wire pushing on the charge carriers in the direction of motion (because the whole thing is moving). This force is doing the work on the charge carriers in this frame (although it is somewhat strange to think of a constraint force doing work).
The push of the current carriers against the wire's constraint force gives the breaking force on the wire, which slows it down so as to conserve energy, as the resistance gives off heat.
Comment: @lubos Motl: Constraint forces _do_ do work in inertial frames when the object is moving, precisely because energy (and its flows) are not Lorentz (Galilean really) invariant. The classic example is: I am on a train going 50m/s and I lean on a pole against the direction of motion, so that it pushes against me with 100N in the direction of motion. So the pole is doing 5000W of work on me! This is correct, because the shift of reference frame mixed the momentum/stress flows in my rest frame into energy flows in the station frame.
Comment: Sorry, but you copied the misconception of the OP that energy is Lorentz-invariant and has to agree in all reference frames. That has led you to "solve" a paradox that never existed. Also, your detailed comments about "constraint forces" are wrong because in this experiment much like in all non-accelerated ones, constraint forces aren't doing any work.
Comment: I'd give this a +1, but the constraint force isn't generally perpendicular to the wire in this case - surprisingly perhaps. The sum of the external force on the metal ions and the Lorentz force gives rise to a net force that causes the wire to move in a particular way. The static electric field of the metal ions provides the constraining force for the electrons, which summed with their Lorentz force must give the same net force for the ions. Hence the constraining force on electrons in some part of the wire depends upon the magnetic field at, and velocity of, that segment of the wire.
Answer: There is no paradox: the two reference frames have different answers to the question "how much work is being done", indeed. It's because "work being done" is nothing else than energy and energy isn't a relativistic invariant; it is the time component of a 4-vector. According to relativity, various quantities are observer-dependent i.e. relative – a justification of the name "relativity" – and energy is one of them.
From the magnet's viewpoint, the electrons' energy may be conserved but the momentum is not. Because the energy from the coil's perspective is a mixture of the energy and the momentum in the magnet's reference frame, and because the momentum is being changed from the magnet's viewpoint, it follows that energy of the electron is being changed from the coil's viewpoint.
With this being said, one should still emphasize that the increased/decreased energies of individual electrons get averaged out around the coil.
Comment: Lubos, this is not a good answer either--- which force is doing the work when the wire is moving?
Comment: Dear @Ron, it's always the electric force $q\vec E$ that is doing work. If $\vec E=0$ in a given frame, then there's no work being done. What's your problem?
Comment: What you wrote is correct, but my problem is that you don't resolve the paradox. The average business you talk about around the coil is only true when the magnetic field is constant and there is no EMF. If the field is changing, the field will do work. The work is actually being done by the constraint forces, not the B field, as explained in my answer. Your answer is suboptimal.
Comment: @RonMaimon: that's what I think, too... but is it actually right? Perhaps there is really no work done in $\mathfrak{M}$, neither by the Lorentz- nor by the constraint force. I don't know how to do the transformations correctly.
Comment: @leftaroundabout: The transformations are done correctly by Lubos, and there is no paradox in the rest frame of the wire. In the moving frame, the constraint force starts doing work, that is all. It is like riding on a subway and leaning on a pole, when you are moving, the force on the pole does work on you(if it is in the direction of motion), balanced by the opposite sign work on your feet.
Answer: I'm not quite sure about this one, but I would explain it this way: (let $\mathfrak{M}$ the frame of reference of the magnet, $\mathfrak{C}$ 〃〃〃〃〃 the coil)

No work is done initially in $\mathfrak{C}$, either: the electrons are at rest in the beginning. Only once the force has started built up some speed there is a finite power.
In $\mathfrak{M}$, the electrons also build up velocity. Even in the parts of the wire which enter the field perpendicularly (sort of), so that the electrons are initially deflected in the direction of the wire, the force will eventually (when the electrons move in the wire) point in a direction other than the wire alignment. Once this happens, only the force component in wire direction will take action, so the effective force direction is not perpendicular to the electrons' moving direction any more. To put it another way: when the electrons are pushed to one side of the wire, $\rho$ becomes macroscopically nontrivial, resulting in an electric field due to $\nabla\mathbf{D}\propto\rho$.
Comment: This is not the resolution--- the magnetic force does no work even when the electrons are moving.
Comment: @RonMaimon: however as I said there is also going to be an electric field in the wire. It seems to be this field that does the actual work, though I can't quite figure out how.
Comment: Not all force in a wire are electromagnetic, there are also electronic forces. Electrons exert a push-pull type Fermi-exclusion, that's what you feel when you put your hand against a table. In this case, though, you are right that there is an electric field in the wire that does the work--- it is the constraint force. Not my downvote, by the way.
Answer: "There is no work because the force is perpendicular to the velocity". I don't think that's right. The v in your formula qv x B is the velocity of the coil, but it is not the velocity of the electrons. The electrons move inside the coil, and they move in the direction that the force is pushing them: perpendicular to the velocity of the coil. So how is there not a force pushing the electrons?
EDIT: In response to Ron's comment about the constraint force, I've worked it out and I think the following picture will show what is happening:
The wire is treated as a pipe full of electrons, and the blue electron shown is actually right against the pipe wall: as the pipe moves upwards, the electron rides along the pipe wall as shown by the blue arrow. The two forces are the vxB force, perpendicular to the electron's true motion, and the constraint force, perpendicular to the wall of the pipe. I think the picture shows that the actual work is done by that COMPONENT of the vxB force which is in line with that COMPONENT of the electron's velocity which is along the direction of the pipe.
Comment: The magnetic force on the electrons is perpendicular to the velocity. It is the constraint force from the wire that is doing the work.
Comment: Ron, I'm going to edit my response with a picture in response to your comment. The constraint force is indeed important, but I think you will agree it turns out to be the vxB force which does the work after all...
Comment: I'm going to eat my words. Having posted the picture, it's pretty obvious that the guy pushing the pipe is doing the work. There is a reaction force from the magnetic field that he is pushing against, and that's why the electrons move to the left, but obviously the magnet isn't providing any energy.


Can you add enlarge person to the ranger spell list without Sword of the Arcane Order?

Question: I want to be casting enlarge person with my Ranger, but for a variety of reasons Sword of the Arcane Order is awkward (low-Int, feat slots, can't take it 'til level 6, etc.). Can it be done without that feat, preferably at low-level?
Answer: There is no good solution, just multiple mediocre ones.
Enlarge person is actually remarkably difficult to get on rangers; Sword of the Arcane Order is of course the simplest, but as mentioned, it has problems for low level and low-Int rangers. If you absolutely need it added to your spell list (for example, needing to be able to cast it as a divine spell for a prerequisite), there is no unambiguously-functional option other than SotAA (and even the ambiguously-functional one, presented at the very end of this answer, is jank and worse than just taking SotAA).
So let's go over the alternatives!
Hidden Talent (Expansion) + Dorjes
Page 67 of the Expanded Psionics Handbook has the Hidden Talent feat, which gets you a 1st-level psionic power off any list and 2 power points to manifest it. Taking expansion with this will let you use that power to get bigger... except that expansion has a 1 round/level duration instead of a 1 minute/level duration, so it's useless on its own. However, being able to manifest the power lets you use a dorje of expansion (like a wand, but for psionics) to manifest the power. A manifester level 3 dorje of expansion costs 2,250gp, and gives you 50 charges of expansion with the augment that increases its duration to 10 minutes/level (so, 30 minutes per use, and probably the most cost-effective pick for this).
(Note that, as dorjes can't be made with a ML more than five higher than the minimum ML of the power, you cannot get a dorje of expansion that uses the alternate augments that speed up the manifestation or increase the size gained. Still, fifty 30-minute-duration size increases are probably the best bang for your buck, and becomes available at 4th level WBL.)
Potions
A potion of enlarge person costs 50gp × the CL of the potion, so you can use that if you're willing to deal with potions having higher action costs than most things (action to draw, action to drink). The duration is worse than the dorje path above, and it's less cost-effective than the scrolls and wands path below, but it at least doesn't take a feat to use.
Touchstones
Per the Planar Handbook, the Touchstone feat (Sandstorm p. 53) allows you to choose planar touchstones, and unlike the Planar Touchstone feat in that book, you can access this feat earlier by having a 250gp focus item keyed to the touchstone in question. The earliest this is available is level 3 due to WBL concerns, but by taking Touchstone for the Catalogues of Enlightenment (Planar Handbook p. 166) you gain access to the granted power from a cleric domain of your choice.
By taking the Magic Domain's granted power, you can now use spell completion and spell trigger items as if you were a wizard of half your cleric level (minimum 1st level). Note that, while it is entirely unstated what your effective cleric level is for the Catalogues of Enlightenment, due to the Magic Domain's callout of a minimum result, you don't need to worry about that. Touchstone (Catalogues of Enlightenment [Magic Domain]) will allow you to use scrolls, wands, staves, and minor schemas as if you were a 1st level wizard, allowing access to the following items:

25gp: Scroll of enlarge person (lasts 1 minute, single-use)
750gp: Wand of enlarge person (lasts 1 minute, 50 uses)
400gp: Minor schema of enlarge person (lasts 1 minute, 1/day use; Magic of Eberron p. 122)

If your DM rules that you have an effective cleric level equal to your HD for the Catalogues of Enlightenment, you could also use the Gluttony Domain (Spell Compendium p. 274), which has the following granted power:

For a total time per day of 1 round per Cleric level you possess, you can increase your size as if you were affected by the enlarge person spell. Activating the power or ending it is a free action.

Duergar Variants
The duergar is a dwarf variant with +1 level adjustment and enlarge person as well as invisibility as spell-like abilities 1/day. Lesser duergar (Player's Guide to Faerûn p. 190) lose the invisibility SLA in exchange for being LA +0, and thus would let you get access to enlarge person from 1st level onward. Likewise, the baseline LA +0 part of the savage progressions duergar also has the same tradeoff; you get enlarge person 1/day but lose several other abilities of the race. With either of these, you can then take the Magic in the Blood feat (Player's Guide to Faerûn p. 40) at 1st level to boost the uses to 3/day.
Specific Magic Items
The belt of growth (Magic Item Compendium p. 73) costs 3,000gp and lets you up your size as if by enlarge person 1/day for 10 minutes. You can afford this by 5th level.
There is also the option of the 100gp shifter braid (Races of Eberron p. 174), which is a consumable item usable only by shifters, activates when beginning your shifting, and grants you enlarge person for the shift's duration at no extra action cost.
Dishonorable Mention: Arcane Disciple
The ambiguously-functional option implied earlier. There are several domains that grant enlarge person as a 1st-level spell, and if your DM follows the school of thought that the Alternative Source Spell or Southern Magician feats would count your ranger levels as arcane spellcaster levels, you could theoretically daisy-chain your way into getting enlarge person on your spell list with that. Note though that this is, even if your DM goes with that (they might not!), still not going to come online before level 6 in all likelihood, and requires multiple feats or a dip. At that point, you may as well just dip cleric or wizard or something and cast the spell normally—it's just not worth it. Still, for the sake of completeness, something like Magical Training into Alternative Source Spell into Arcane Disciple (Strength Domain) would work. But don't do this.
Comment: Great answer! As a side note: a potion belt (from Forgotten Realms Campaign Setting)(price: 1 gp!) reduces the action cost for potions to one standard action.
Comment: @Peregrin Did someone say [potions?](https://rpg.stackexchange.com/a/115045/8610)
Answer: On page 198 of the 3.5e DMG, there is a section titled Researching Original Spells.
Similarly to this answer about adding a sorcerer spell to the wizard spell list, if the DM allows it, a ranger can research a spell and try to have it added to the ranger spell list. If you can find similar spells that show that this kind of spell should be allowed for a ranger, then perhaps that can help get it made at your table.


Can a smooth function have all derivatives positive for $x>0$ and $0$ at $x=0$?

Question: Can we have a smooth function, say $f: [0,1] \mapsto [0,1],$ such that $f^{(k)}(0)=0$ and $f^{(k)}(x)>0$ for all $k \ge 0,$ $x>0?$ I suspect this is impossible, but I'm not sure how to prove this.
Comment: Take the standard mollifier.
Comment: I fail to see how a mollifier satisfies the properties I asked for.
Comment: Yes, you are right. The second derivative of the mollifier $f(x)=e^{\frac{-1}{1-(x-1)^2}}$ already gets negative: http://www.derivative-calculator.net/
Comment: While I am too sick to spend much time on this, I stongly suspect you are mistaken. I can see no reason it would be impossible.
Comment: I certainly hope I'm mistaken. I've been trying to construct such a function.
Comment: What if $x=\exp (-1/f(x)^2)$ for $0<x<1$ ?
Answer: $f^{(n)}(x)$ should be convex for all $n\ge 0$ on $[0,1]$. This means in particular that
$$f^{(n)} \left( \frac{t}{2}\right)\leq \frac{1}{2}f^{(n)}(t),\,\forall n\in\mathbb N$$
Integrating this we get
$$\int\limits_{0}^{x}{f^{(n)} \left( \frac{t}{2}\right)dt}\leq \int\limits_{0}^{x}{\frac{1}{2}f^{(n)}(t)dt}$$
$$\Leftrightarrow f^{(n-1)}\left(\frac{x}{2}\right)\leq \frac{1}{2^2}f^{(n-1)}(x)$$
We integrate this $n-1$ more times to get
$$f\left(\frac{x}{2}\right)\leq \frac{1}{2^{n+1}}f(x)$$
Since $n$ was arbitrary it follows that $f\left(\frac{x}{2}\right)$ should be $0$ for all $x\in[0,1]$, i.e $f(x)\equiv 0$ for $x\in [0,1/2]$.
But we can also apply convexity with arbitrary $\lambda \in (0,1)$ to get $f(\lambda x)\leq \lambda^n f(x),\forall n\in\mathbb N,\,\forall \lambda\in(0,1)$ and therefore we get that $f(x)\equiv 0,\,\forall x\in [0,1)$ and by continuity also $f(1)=0$.


Is there any proof of law of karma?

Question: is there any proof of law of karma and other writings of the scriptures. I have read another answer which says you have to experience it but is there a place/temple where I can get solid proof?
Comment: Throw a stone straight up and don't move. The proof will become self-evident in a few sec.
Comment: The devi bhagwat and many scriptures state that everything happens is pre planned and is wish of the mother, so there is no karma at all because it was done by the mother.  For example this message was the wish of mother
Answer: The doctrine of Karma and rebirth or reincarnation are linked together in Indic religions and philosophies. Karma works across lives, which renders it impossible to show it's validity through scientific process without first proving the existence of rebirth and the system which leads to consistent death and rebirth (saṁsāra). There is lack of a scientific way currently to verify of how one's previous life (if even there is) may have an effect on present life.
But just because the doctrine of karma can't be proven scientifically, that doesn't mean there aren't any means to assert it's validity in Indian philosophy. Validity of knowledge in this context is shown through the use of pramāṇas (means of valid knowledge). Different schools accept different no. of pramāṇas.
We would take Advaita Vedānta here, which accepts six pramāṇas: pratyakṣa (perception), anumāna (inference), upamāna (comparison/analogy), arthāpatti (postulation), anupalabdhi (non-cognition) and śabda (verbal or scriptural testimony).
We would analyze which pramāṇas can be applied and the school of Advaita used to demonstrate the validity of karma. I am presuming, here that the reader is familiar with the basic definitions and usage of six pramāṇas because if I include that, the answer would become much longer.
(i) Pratyakṣa (perception) : External perception is useful in yielding knowledge of qualities (such as color, size, texture) of objects (such as table) and the relations that constitute it (such as universal 'tableness') but it doesn't and cannot yield knowledge of law-like (such as law of Karma) relations b/w objects in nature. Just to clarify, law, here doesn't mean scientific law.
Karma operates in the world through merit (puṇya) and demerit (pāpa). Although, these two states are modes of antaḥkaraṇa (mind as internal organ), but they aren't internally perceivable such as pain and pleasure because they lack of perceivability. (Hiriyanna, 2005, p. 346)
(ii) Upamāna (comparison) : Karma can't be proved by upamāna either. If we use the analogy of say, an apple that is sown, ripens, dies and grows again through it's seeds (reincarnates) and apply it to the case of reincarnation of humans, it only generates a probabilistic knowledge (yukti) but not certain knowledge which a pramāṇa which should be able to confer.
(iii) Anupalabdhi (non-cognition) : Clearly non-cognition of an object or phenomenon doesn't always imply that it's non-existent. (one can't judge the non-existence of chair in dark room because we don't have any visual knowledge of it). The rāja yogins claim that by bringing saṁskāras (residual tendencies) into consciousness through saṁyama (controlled concentration), the knowledge of previous lives is obtained (Yogasūtra, II, 18). Although Advaitins don't use this as a support for karma or rebirth, but they do support the claim that such knowledge can be acquired. And if they do use it as support of karma and rebirth then they would fall in the same difficulty as that of the adherers  parapsychology, of establishing new empirical laws of nature on the basis of the extra-sensory perception of priviliged few (in this case, the jīvanmuktas). Without access to data of the previous life and confirming it with karma, karma is undemonstratable. So, Karma can't be proved by anupalabdhi.
(iv) Anumāna (inference) : As we know a valid inferential cognition is only obtained if there is vyāpti b/w sādhya and hetu, from which the inference is made. Karma cannot be a genuine vyāpti because the consequences of moral action, as affecting over a period of innumerable births, is largely unseen, and hence they cannot be seen to be in uncontradicted relatedness to the actions. For Advaita, inference depends on perception and cannot extend further than drawing out the implications of the relations based on perception. Advaitic tradition itself concedes that truths about dharma and Brahman are non-inferential in nature. So, Karma cannot be proved by anumāna either.
According to Advaita, Brahman or ātman isn't subject to karma. In it's true nature Self is eternal and hence untouched by anything that pertains to the jiva of the empirical world of names and forms(nāmarūpa). Karma, so becomes a 'relative' idea, and it doesn't follow from the real nature of the Self. It's necessity isn't logically implied by the Advaitic metaphysics and its denial doesn't lead to consequences that are self-contradictory. Karma, therefore, when looked upon as a rational concept or idea as distinct from empirical, scientific theory, is not demonstrated, and within Advaita Vedānta, it's rationally undemonstrable.
(v) Arthāpatti (postulation) : According to some interpreters of Advaita such as Dharmarāja in his work Vedāntaparibhāṣā, Karma can be justified by arthāpatti.
Advaitins use this pramāṇa in supposing some unperceived facts and principles for explaining experienced facts. They may argue that the assumption becomes justified and is valid knowledge if the fact assumed is the only one that can explain all necessary and indispensable suppositions, such as the law of Karma is necessary to explain the otherwise inexplicable good and bad lucks, and existence of God for explaining the distribution of fruits in accordance with an individual's actions etc. These are cases of arthāpatti often used. (Datta, 1972, p. 246)
However, this view can be refuted in the way that, by justifying karma using this pramāṇa, in the way above, it doesn't fulfill the requirement of uniqueness. Karma is surely not the only supposition that accounts for the good and bad lucks of persons (such as differences in their moral, intellectual or spiritual capacities) as indeed many others (e.g., divine predestination or natural hereditary factors) have been put forward and have been capable of generating strong belief. Karma is thus not established by arthāpatti as it's not the only way by which inequalities can be made intelligible.
(vi) Śabda (scriptural authority or verbal testimony) : This pramāṇa is often used to justify Karma by advaitins. But this also has it's problems. Deustch argues that experience of ultimate reality in advaita is defined to be 'of identity', devoid of sequential time-past, present, future, and when one is in such a state (samādhi, turīya, nirvikalpa) which transcends all categories of time, how can Karma really be a content of spiritual experience.
Although the above argument is sound, it overlooks the fact that śruti is a source of knowledge, not just of Brahman but also dharma, and dharma transcends reasons and senses, here. Secondly, the Veda proclaim the doctrine of Brahman, but they are themselves part of Māyā.
In Māṇḍūkyakārikā IV.73, Śaṅkara says that, "the existence of objects such as scripture etc. , is due to empirical existence which is illusory...  Scripture[and the distinction b/w] teacher and taught is illusory and exists only as a means to the realization of reality.".
So, a scripture in the domain of Māyā, can surely be a source of valid knowledge of what is valid within Māya, the realm within which the doctrine of Karma falls and that's clearly upheld in the mukhya Upaniṣads. In this way, karma can be established by śruti by the means of śabda.
As above, we have shown how karma could not be established rationally or empirically as in Deustch (1969) and it's review by Sharma (1990) which points out some of the problems with the former's view that is included in my analysis. A traditional advaitin may use arthāpatti and śabda, śabda being given more emphasis, since it's shown to hold rationally.
A modern Advaitin will probably concur with Karl Potter though (the excerpt is modified on scientific exploration by make sense for current research in physics),

One major criticism of karma theory is that it's untestable, but similar criticism can be made of theories in physics, for e.g. , string theory or multiverse scenarios etc. Defenders of the theories in question respond that that these difficulties are technical or technological, that in principle the theories are testable at least within broad limits or at a certain point of time in the future. But surely the same can be said of karma theory. It's not in principle untestable, though in practice it is because of technical difficulties. The difficulties arise from our inability to determine with precision which person alive inherits which person's past karmic residues. If one complains that is precisely the responsibility of the karma theorist to convince us that that rebirth takes place at all, that there are any karmic residues, the parallel complaint may be recorded against the physicist who postulates unobservable particles. In both cases, it is clear enough that what is to be explained is observable; in both cases the explanation involves postulation of unobservables. Technological advances may in time make possible testing of both type of theories- we may build bigger and better better experiement or observational tools such as LIGO  and find theoretical ways probably of discovering strings at higher orders of energy, and likewise we may possibly discover ways of identifying karmic residues and vāsanās and so of re-identifying them in another body at a later time. (Potter, 1980, p.259-260)

References

Deutsch, E. (1969). 5 Karma. In Advaita Vedānta: A Philosophical Reconstruction (p. 67-80). Honolulu: University of Hawaii Press. https://doi.org/10.1515/9780824841690-007
Sharma, A. (1990). Karma and Reincarnation in Advaita Vedānta. Journal of Indian Philosophy, 18(3), 219–236. http://www.jstor.org/stable/23445563
Hiriyanna, M. (2005). XIII. Vedānta. (A) Advaita. In Outlines of Indian Philosophy. (p. 336-382) Motilal Banarsidass
Datta, D.M. (1972). The Six Ways of Knowing. University of Calcutta
Murty, K.S. (1959). Revelation and Reason in Advaita Vedānta. Columbia University Press
Potter K.H. (1980). The Karma Theory and Its Interpretation in Some Indian Philosophical Systems. In W. D. O'Flaherty (Ed.) Karma and Rebirth in Classical Indian traditions (p. 241-267). University of California Press.

The Buddhist perspective on Karma and rebirth would be very interesting but the answer is already quite big. The notion of karma is not exactly the same in the Buddhist schools and the Vedic schools, and it's worth pondering over the Buddhist notions, because those are also very reasonable, especially on rebirth, they have offered more stronger arguments. I would recommend you to check out Dharmakīrti's proof for rebirth and how he argues for it in his work Pramāṇavārtikka.
Comment: good analysis . upvoted. yet few comments. (In section shabda pramana)  Tattva drishti and Vyavaharika drishti are mutually exclusive, and  must not be enjoined.
If seen in tattva drishti , then the context (of karma and frutition) is lost. Broad spectrum of truth is beyond human scrutiny , hence shabda pramana takes precedence over other pramanas.
Arthapathi also inturn relies on shabda pramana only .(here as rationale is insufficient to establish any proof for law of karma)
Comment: I hope (I'm nt sure) , Buddhists may only have few discords , like, they may not accept- Atma, the antaryami is not tainted by Karma(as they don't agree with atma). Secondly they may not accept , God , the sole subduer of Maya is the only dispenser of fruits of Karma.Looks like their karma theory does not rely either on verbal testimony or on rationale
Comment: @Athrey Yes, karma theory in Buddhism is not the same and it doesn't depend on śabda. Dharmakīrti accepts only anumāna and pratyakṣa as pramāṇas as Dignāga, and according to him all other ways are reducible to those two. But it's rational.
Answer: Yes.
The modern scientific domain of Complex Systems Theory has a detailed treatment of how karma works. After all, humanity is a complex system with many agents.
Within Complex Systems is the concept of Chaos. And in Chaos Theory, there is the concept of what is simply referred to as the "butterfly effect".

In chaos theory, the butterfly effect is the sensitive dependence on
initial conditions in which a small change in one state of a
deterministic nonlinear system can result in large differences in a
later state.

Karma works in a similar way. It is the nonlinear or disproportional effect perpetuated by agents in a complex system. Essentially, it is cause and effect.

Is there any proof of law of karma?


Impact of deleting mysql_embedded, mysqltest_embedded, mysqld-debug, mysql_client_test_embedded

Question: In my MySQL install, i see bin directory consuming 1.3 GB of data. Noticed the following things which look like utilities
mysql_embedded, mysqltest_embedded, mysqld-debug, mysql_client_test_embedded, mysqlxtest, mysqlpump
Will there be any impact to start the database because of deleting these?
What is the minimum i should have in my bin directory to be able to start mysql?
Answer: MySQL distributions include a test suite: a set of test cases and programs for running them. These tools constitute the MySQL test framework that provides a means for verifying that MySQL Server and its client programs operate according to expectations. Where I suggest you do some further reading --> MySQL-Test-Introduction
As to the question regarding the minimum size of the binary in order to start MySQL I would advise against deleting these files if you do intend to running test on your system during or after development.
However, these files are not actually used during the building of the database system.
I hope this helps somewhat...


How to know a good pump?

Question: It's painful to pay the local price of 15-30€ for a pump that is "very good, durable and small". To me, it is just consumable that I will use until it breaks, so I have no interest in investing too much in such a thing. How can I know what the pump is like? Are there some factors to look at to judge its quality?
Comment: Like mgb says, get a floor pump. http://bicycles.stackexchange.com/questions/811/what-is-the-best-floor-pump - The small ones that fit on your bike are generally for road flats and don't get used all that often, so tend to last a while.
Comment: "...use until it breaks..." with a cheap pump seems like a bad idea. The last thing I want is for a pump to break when I'm out on the road with a flat. ;~)
Comment: Get a pump that's able to inflate your tire to the right pressure. If your tires need high pressure, you might not be able to achieve that with a small hand-pump.
Comment: @wdypdx22: low price does not necessarily mean poor quality, it is more about you: *are you able to maintain the pump and can you choose the right tool in the right place?* I have used 5EUR car leg pump, very durable and very cool meter. I have used 5eur small hose pump and 5 eur small non-hose pump. None has failed when I maintain them with proper grease and at the right place, sure it took some time to dig them and not to get attracted by flashy gizmos, but yeah I am still open to really `"good pumps"` -- particularly looking for good touring options like durable air-efficient hose pump.
Answer: I got a Topeak Pocket Rocket a few years back at the LBS spring sale for ~$25. Works great. I made $10 the first time I used it because I didn't have to pay a $35 cab fare to get back home after a flat on a country road.
Fits in my pocket, the nozzle has a snap-on cover, works with Presta/Schrader, it's made of aluminum, feels solid and most importantly gets my tires to an adequate pressure.
For floor pumps, you can check out this thread: What is the best floor pump?
Comment: wdypdx22: the alu here may be a valid choice, I broke my long plastic cheap-junk pump during winter (no idea what it costs but cheapest possible long one) -- apparently because of old age. But drawback buying expensive looking item is the cost of losing it is then greater. But perhaps some small metallic to carry in bag would be ok, I have only experience of very tiresome small plastic pump and never got my tires inflated with it.
Comment: Is it easy to use the small pump? Have you noticed some differences?
Comment: It's definitely not as easy to use as a floor pump, but it's not very difficult to use. The purpose of the portable pump is to get me rolling again when I have a flat on the road.  It's not for routine tire pressure maintenance.
Answer: I think there are 3 main factors when reviewing a pump.

Valve connection method, clamp/screw.
Valve support (not every pump supports both types of bike valve, but most do)
How high a pressure tire do you need? (some road bikes need really high, > 100 psi).

A lot of modern pumps use a clamp to secure to the valve.  These tend to be awkward when you're completely flat and quite challenging to pump assuming there is no hose between the pump and the clamp because you have to keep the pump rigid while pumping to prevent the connection being broken.  I personally favour the more old fashioned way of having a screw on hose.  There are some manufacturers who still do them.  They're also less likely to break off under high pressure.
There are some extra requirements that might be important to you.

Size
Bike fitting (may not be that important)
Extra features - some contain compartments for puncture repair patches
Ease of pumping - pumps will push in different amounts of air per stroke so some are easy but take a long time to pump up.

I have a good bike fitting for my pump but I don't use it on commutes because it's simpler to keep my pump in a pocket on my bag.
Once you've found one that looks like it meets your requirements check out the reviews on the bike shopping sites.  They should warn you of potential downfalls with the products.  You might also want to see if your local bike shop can let you try out a demo.  Do it from flat on your own bike because that will give you the most realistic test of a pump.  Pumping an already inflated tire is too easy.
As far as practical recommendations go I personally recommend the small pumps from Lezyne.  (I would link to their own site but it's all flash.)
Comment: +1 I like the hose because of easier pumping, cannot understand why they would be old-fashioned. Pumping even 5-6 bar tire with small hose pump is a challenge, any experiment done how such tires should be pumped? I feel it inhumane thing to do in awkward position. Tried it during winter and failed but luckily I had a leg car pump with me that time.
Comment: Pumps without a hose can also damage more delicate valves while you're pumping (i.e, Presta valves) unless you keep the pump very firmly held.
Comment: Agree on the Lezyne pumps, though they're a bit more expensive than the other pumps. The hose that stows inside the handle is clever, works well, and keeps the most important parts clean.
Answer: My advice:  Get a floor pump with a pressure gauge and an easy way to switch between shraeder and presta.  and get one that is servicable.  I have the topeak Joe Blow.  Take a look at the dual nozzle.
Also get a portable pump.  There are several kinds that unfold and remove the pain of portable pumps (I could never get a good pressure in those because they require you to hold it steady while pumping.  (One time I tore my freaking valve off my inner tube)
I got a topeak road morph.  You can unfold a little foot brace, unfold the handle and it has a flexible tube to attach to your valve, so it is almost as easy to use as a floor pump.  I've saved myself some long walks and pumped up other's flats.  And it has taken abuse, is super light.  I think I got it for $35.00 US.  It also has a gauge and, according to this thread, is user-servicable.
Comment: +1 for suggesting a hose pump, I don't like taking all of my touring load from my bike to pump a tire with a non-hose pump. I know there are people who blame to be good at that but I am proud about the lazy way of pumping in good position without risking the inner tube -- excellent point! The topeak road morph sounds promising, very useful thread. Thank you.
Comment: With your on-bike pump, make sure it has something to stop crud getting in through the valve hole when it's not in use. Otherwise you end up with mud and stuff that you have to scrape out before you can use the pump.
Answer: Good, durable and small is tricky - personally I would get a track pump for home and a small cheap pump to carry with you.
In a small pump I would go for simple. So no double rate fast/slow mechanism, no complex foldable handle
Look for a presta adapter that won't just come off and get lost (assuming you need one)
Basically just look for solid feeling construction.
If you are carrying it on your bike I put electrical tape around the valve end to keep it clean.
If we are recomending individual products, I have one of these as an emergency 'get you home' pump. It's presta (road bike) only, but that means no adapter to lose, it's very small and lives duct-taped to the frame.
Comment: @hhh presta is harder to pump by hand because the pressure is so much higher. There are adapters to let you use a shrader (car) pump. I would NOT use an air line, the volume in a road tire is very small so will fill very quickly and an exploding tire is very dangerous.
Comment: how does the pump work? Is that a foldable handle? Sorry but my personal bias is to use car-adaptered tires so I can go to gas-stations to inflate tires. Haven't understood yet the presta thing, does it help you pump a tire more easily?
Comment: about Presta, it is a smaller hole so it is easier to pump with hand: http://en.wikipedia.org/wiki/Presta_valve, now a dilemma. Can I fill presta tires in gas-stations perhaps with some adapter?
Comment: @hhh yes the handle folds to give a thin shape to carry but then unfolds so there is something to grip. The small hole is for a road bike (presta) valve. One problem is that without a flexible hose you have to be very careful not to bend the end of a presta valve when pumping. That's why you use a track pump if possible
Comment: *air line*? If you mean gas-station pumps by *air line*, I have filled my tires that way many times. It takes just 1 second but you need to deflate before filling. Never exploded but very good thing to consider, never really thought about that,thanks.

How to know a good pump?


Use of onDestroy( ) in Android

Question: If Java provides Garbage Collection, then what is the need of onDestroy() in Activity Lifecycle?
Comment: Check this :

[What exactly does onDestroy() destroy?][1]

  [1]: http://stackoverflow.com/a/4981927/556975

Hope it helps you.

Thanks.
Answer: onDestroy:  The final call you receive before your activity is destroyed. This can happen either because the activity is finishing (someone called finish() on it), or because the system is temporarily destroying this instance of the activity to save space.
Here is an example......
 public void onDestroy() {

   super.onDestroy();

 }

Comment: You can not count on onDestroy() being called.  "There are situations where the system will simply kill the activity's hosting process without calling this method (or any others) in it, so it should not be used to do things that are intended to remain around after the process goes away." http://developer.android.com/reference/android/app/Activity.html#onDestroy()
Comment: I was going to edit but edit queue is full. So, using the suggested code is the same as nothing because thats what the system does by default. You should edit and add a inside the activity: //todo before destroy
Answer: OS decides when things "go away." The onDestroy is there to let your app have a final chance to clean things up before the activity does get destroyed but it does not mean that the activity will, in fact, be GCed. Here is a good article that I recommend people to read that relates to creating an exit button. While it's not exactly what you asked about, the concepts will help you understand what's going on.
Answer: You can use onDestroy() to finalise the program. I have used it in the code bellow to tell the server that the client is closing its socket to the server so I can notify the user on the server end that the client has disconnected.
client:
...
protected void onDestroy(){
    super.onDestroy();
    if(connected) {
        clientMessage.println("exit");
        clientMessage.close();
        try {
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    finish();
}
...

server:
...
while (connected) {
    input = clientMessage.readLine();
    if ("exit".equals(input)){
        break;
    }
    ...
}
...

Answer: onDestroy() is a method called by the framework when your activity is closing down. It is called to allow your activity to do any shut-down operations it may wish to do. The method doesn't really have anything to do with garbage collection (although your shut-down operations—if any—might involve releasing additional resources that can be gc'ed). In particular, it has nothing to do with C++ destuctors (despite its name).
If you have no shut-down operations to do, you don't need to override it. The base class does essentially nothing.
Answer: onDestroy may be called when an activity is destroyed, but you can not count on it. There are situations where the system will simply kill the activity's hosting process without calling this method (or any others) in it, so it should not be used to do things that are intended to remain around after the process goes away.
See: http://developer.android.com/reference/android/app/Activity.html#onDestroy()
Answer: In the Android Activity Lifecycle's onDestroy docs:

onDestroy() is called before the activity is destroyed. The system
invokes this callback either because:

the activity is finishing (due to the user completely dismissing the activity or due to finish() being called on the activity), or the
system is temporarily destroying the activity due to a configuration change (such as device rotation or multi-window mode)

The Activity#onDestroy() API docs also answers it quite well:

This method is usually implemented to free resources like threads that are associated with an activity, so that a destroyed activity does not leave such things around while the rest of its application is still running. source

As the quote from the docs say, its for preventing a destroyed activity leaving things around (e.g. memory leaks through referencing, threads), but only when the rest of the app still runs. If the application process ends, it doesn't matter if you forget to clean up threads or other resources since the OS will do it for you. You don't need to override onDestroy.
There is no need to do what sam786 is doing (overriding and just calling the super method) as that is absolutely useless. All other answers seem to go along the lines of "clean up", but don't explain what kind of clean-up or when. You should not be saving any data in onDestroy(), as you can't guarantee it will be called, so you will lose data sometimes. It won't be called when you press the home button, for example (the case where you want data to be saved).
Answer: The onDestroy is there to let your app have a final chance to clean things up before the activity does get destroyed
Article Exit Button in Android
Answer: It gives your program a chance to do things like cleanup resources (say threads) so that they don't pollute the associated application.  If you don't have any use for it, then don't override it.
See:onDestroy()-Android Reference

Use of onDestroy( ) in Android


Strange night-day planet design

Question: I've posted a previous question similar to this in the way that it is of my WIP web-comic. The planet my friend and I have designed is strange as she wanted to create either a permanently dark planet, or a planet divided by dark and light. I'm for it as it lets me create an even more biologically diverse ecosystem (as I'm creating 85% of the alien life) though I've run into the problem of realism. As people have pointed out, and I already had a small idea of, a tidally locked planet would facilitate a dark/light surface. What I'd like to know now is if there is a way to make a credible planet with a completely dark surface that is still warm enough and well lit to cradle life, including plant life.
Comment: Hi Jesse, welcome to Worldbuilding SE. There are already some questions about so-called tidally-locked planets. Like [How extensive could a habitable twilight zone be on a tidally locked planet?](https://worldbuilding.stackexchange.com/questions/358/how-extensive-could-a-habitable-twilight-zone-be-on-a-tidally-locked-planet?rq=1). You should consider review those, and modify your question if they don't answer all your questions.
Comment: @bilbo_pingouin - agreed; Jesse, I think you could edit it to be an all-dark planet, I like that question.
Comment: Jesse, did you make the edit anonymously? If not, and you don't like it, you can roll it back.
Comment: @HDE226868 Jesse does not have a registered account, or at least the account associated with this post is not registered. **Jesse,** you may want to register an account. See [Why should I create an account?](https://worldbuilding.stackexchange.com/help/why-register) for some of the benefits, and [How do I create an account?](https://worldbuilding.stackexchange.com/help/creating-accounts) for how to actually do it.
Comment: "Completely dark surface" and "warm enough and well lit" seem to be at odds with each other. Could you clarify?
Comment: A planet with enough cloud cover could be dark on the surface; something similar to Venus, but further from its star, so that it isn't as hot.
Answer: It is easy to have a planet with a light and dark side.  If the planet is tidally locked with it's star, one side will always face the sun and the other away from it.  That is easy, however, on such a planet most of the life will be on the twilight edge.  Different factors would go into how far into the sun or into the 'night' you can go and still be in a livable environment.
Plants as we know them need sunlight to live, so 'plants' would not live on the dark side of the planet.   However, thermal vents could provide enough heat for other life forms to survive, we have them living in the ocean deeps right now, the 'plants' would likely be more like molds and fungus, things that don't need light to survive.  which also makes the life forms much more exotic.
Toward the sun will be more and more desert like until you get to a (most likely) barren sun scorched area. and farther and farther to the opposite side will be more like a polar night, cold and lifeless.  The vast majority of life will crowd around the twilight area and thin out as you spread out.
Comment: I suggest watching this video about such a tidally locked planet that was 'designed' by NASA scientists and others from europe. http://www.dailymotion.com/video/xkdb8x_extraterrestrial-aurelia_tech
Comment: Reminds me of one of the possible fates for Earth if we [lose our moon](http://www.quora.com/What-will-happen-if-our-Moon-suddenly-disappears).  The 23 degree tropics of capricorn and cancer are where they are because the moon limits Earth's wobble to only 23 degrees.
Answer: On top of said tidally locked places, you could consider a theoretical alternative: A dark star. Basically a black hole, with only the radiation as a source of heat for the world. This would present a number of challenges for the species living in this planet, the most obvious one being the requirement to let the radiation of the dark star through the atmosphere.
Two rather unique challenges come to mind with this. Since the planet won't have any light worth mentioning, other senses are required to compensate. Cold-blooded to avoid detection, sonar, very light sensitive eyes, etc. As all the radiation would still need to get through and heat up the planet, we either would need an atmosphere that probably has no ozone layer to filter out UV, and perhaps even a very weak or nonexistant magnetic field. So a very ancient world that has it's core cooled down to a standstill, with a very different type of thin atmosphere to let all the radiations through. This still presents the challenge that with a less dense atmosphere, the heat would also dissipate to space a lot quicker, so perhaps the planet would still require to be tidally locked to keep even one side warm enough.
Answer: Seeing that the tidally locked phrase was added in the modified version of the question, I would first answer O.P.'s query about a planet where night and day sides are permanent.
Yes, such planets do exist and they are technically known as "tidally locked" planets. Several of these have been discovered by researchers. Take for example, the case of Bellerophon and Osiris (not the hero or god, but planets).
Now to your next problem. As you might see in detail of the above mentioned planets, tidally locked planets are most often (but not always) "Hot Jupiters". As in, they are incredibly huge planets, mostly composed of gas (instead of rocky material like earth) and they are terrifyingly close to their parent stars. On the above mentioned planets, the temperatures on the bright sides would be in thousands of degrees C (temperature of wood-fire flame is ~800 degrees). You seriously do not want to put your aliens in such a planetary hell.
But you appear to be in some luck. This article should give you some prerequisite knowledge as to where to place your tidally locked planet to make it habitable. It also discusses other aspects of a tidally locked planet that might make it suitable for life.
Plus, remember to add an ozone-like layer for protection from ultraviolet radiation. Also don't forget to add a strong magnetic field to your planet (if there's is a mention about it ever in the story of your planet) and keep it a terrestrial/rocky planet. Don't put your poor aliens on a gas giant.
Answer: You could design a rogue planet
https://en.wikipedia.org/wiki/Rogue_planet
Just give it an active enough core to maintain a warm enough atmosphere for life and a magnetic field
Comment: Yes, though you can edit your answer to add it there, instead of just in the comments
Comment: Could you expend this answer?  World building tends to like more than one sentence answers with a link.
Comment: a rogue planet orbits a galactic core instead of a star, one could support life with an active mantle and core but receives no sunlight (only starlight) so it would be permanently dark. Life on such a planet would be like the aquatic life in the deepest ocean trenches and caves of earth, any mammals would probably evolve without eyes. An alternative would be two tidally locked planets with the inner one casting a permanent shadow on the other, i was just suggesting a planet to build the world on, does this help?

Strange night-day planet design


Curvatures preserved under the Kahler-Ricci flow

Question: Maybe it is a trivial question.  Is there any obvious reason that non-negative holomorphic bisectional curvature is preserved by (normalized) Kahler-Ricci flow, but non-negative Ricci curvature is not preserved by Kahler Ricci flow? More precisely, how can I see it explicitly from the maximum principle argument?
Answer: I am assuming you are asking the question on a compact Kahler manifold. You can find argument in Mok's paper for the part of non-negativity of holomorphic bisectional curvature (HBSC) is preserved under Kahler Ricci flow.(http://projecteuclid.org/download/pdf_1/euclid.jdg/1214441778)
 Roughly speaking, we need to compute the evolution equation of HBSC, then we will get a quadratic term involving curvature besides the heat operator. If the quadratic term satisfies "null vector condition", then the maximal principle will get us the result.
Answer: This is the conjecture of Feldman:
The answer is in the page 207 of this book: The Ricci Flow: Techniques and Applications: Part II: Analytic Aspects
See here


Blurry image from Illustrator to Word

Question: I am saving a logo from Illustrator and my client wants to import it into word. I save the file as a .pdf as been told by this sight and the image comes into word slightly blurry but blurry enough that it looks unprofessional. Any thoughts here?
Answer: In Illustrator select the logo and copy it. Paste it in Word using Paste Special.
In Paste Special dialog box choose Picture (Enhanced Metafile). The Enhanced Metafile format can contain both raster than vector images.
This is the only way to insert vectors in Word (and other Office applications). You will be able to resize it without loss of quality.
In Illustrator you can save the logo in EMF format using File > Export and choosing the EMF extension.
https://blogs.msdn.microsoft.com/openspecification/2011/06/28/emf-file-overview/
Answer: It's actually always best to use RGB raster files for Word.
Yes, Word claims to support eps or wmf and you can insert those formats. The problem is, unless you know how to deal with Word randomly having issues with those formats, they can be problematic.
For a client with little or no graphical sense, export your Illustrator logo as a PNG with transparency. Export it at a fairly large size, then reduce it once it has been inserted into Word.

Blurry image from Illustrator to Word


Is there a difference between 近几年 and 这几年?

Question: Does anyone have an idea whether there is a difference in meaning between  近几年  and 这几年?  I have the feeling that  近几年 is more formal - but correct me if I'm wrong!
Comment: What gave you that feeling?
Comment: 近几年 I have only read never heard!
Answer: As a native Chinese speaker, I would say that your feeling is correct.
Usually, "近几年" is used in the news - like in newspapers and on the news on TV or  in broadcasts.
Anyway, they are interchangeable, so don't worry about the usage of them. They have the complete same meaning.
Answer: They are interchangeable and have the same meaning in almost all cases. However, 近幾年 is slightly more genteel and tends to appear in literatures.
In daily conversation, we generally say "這幾年".
Answer: 近几年 = the several years near to (implicated:) this year or now
这几年 = these several years. These here often indicate the current year or now
Comment: Does this not include this year then?
Comment: so, I could also say 近几年 for the previous three years (of another time) like

1993年的近几年经济不景气  (or something along those lines)
Comment: @Stephone, you say 1993年这几年 because means near to this current year. 这几年 can mean the year of reference, which in the sentence is 1993. However there also could be 那几年 where 那 means that. If you say 1993那几年, the year of reference is current year, but you used 那 to refer to a concept(1993) that is not in current scope.
Comment: So I shouldn't say
1993近几年?
Comment: @Stephen: No you should say 1993年这几年 or 1993年那几年. You don't say 1993年近几年. The difference between 1993年这几年 and 1993年那几年 is the time of reference. The first one sets the time of reference to 1993, while the second one does not.
Answer: 近几年 - recent years
这几年 - these years
"recent years" refer to the immediate past. "these years" refer to the past, present and possibly has the implication that it may extend to the immediate future.

Is there a difference between 近几年 and 这几年？


date formatting in php

Question: I have a string as mentioned below:
$ts  = "3/11/09 11:18:59 AM";

which I got using the date() function.
Now I need to convert this to a readable format like below
11-Mar-2009

I have tried everything using date(). How can I achieve this?
Answer: You need to convert it to something you can use for further formatting. strtotime() is a good start, which yields a unix timestamp. You can format that one using strftime() then.
strftime("%d-%b-%G", strtotime($ts));

Comment: True, It doesn't work on *every* installation - there are windows builds with this function, though. You can use date() instead, if you want to.
Comment: @Vadim: Which PHP for Windows installs doesn't it work under?  strftime() is a wrapper over the C call of the same name, which is a standard part of time.h.  As I recall, date() is also a wrapper over strftime(), but does more for you.
Answer: If you initially get the string from the date() function, then pass on formatting arguments to the date-function instead:
date('Y-m-d')
instead of converting the string once again.
EDIT: If you need to keep track of the actual timestamp, then store it as a timestamp:

// Store the timestamp in a variable. This is just an integer, unix timestamp (seconds since epoch)
$time = time();

// output ISO8601 (maybe insert to database? whatever)
echo date('Y-m-d H:i', $time);

// output your readable format
echo date('j-M-Y', $time);

Using strtotime() is convinient but unessecary parsing and storage of a timerepresentation is a stupid idea.
Comment: Thats not an option as I need to get the time as well.
Only while I am displaying I need in the mentioned format
Comment: You should keep the date in an easily used format for the computer itself, not as a string. the return of the time() method is a good start, and then pass that variable as the 2nd argument to date() for formatting. I'll update my answer.
Answer: Actually I tried doing this and it worked.
echo date("d-M-Y", strtotime($ts));

Comment: I would recommend this over the current answer as it works in Windows as well.
Answer: You can use the date() function to generate the required format directly, like so:
date("j-M-Y");

See www.php.net/date for all the possible formats of the output of the date() function.
Comment: Thats not an option as I need to get the time as well.
Only while I am displaying I need in the mentioned format

date formatting in php


Evaluating $\sin15^\circ$ using Definition 2 of Trigonometric Functions

Question: I am studying trigonometry from Cynthia Young's book(it is a long book).
 I have studied the Definition 2 of trigonometric functions(The Cartesian Plane) but not the Definition 3(Unit Circle Approach).
Using the Definition $2$,I can very easily calculate the trig. functions of $30°,45°,60°,120°,135°,150°,210°,225°,240°,300°,315°$ and $330°$ because $30-60-90$ triangles and $45-45-90$ triangles are special triangles.

But if i try to calculate $\sin 15°$ using Definition 2 of trig. functions,I'm unable to.
But there must be a way of doing this.
So,my question is that-A $15°$ angle has been drawn on the cartesian plane.It passes through a point whose x-coordinate is $2$.  What is the $y$-coordinate of that point?
Because after knowing this,I'd easily be able to calculate $\sin 15°$ using $\sin\theta=\frac{y}{r}$
Answer: use that $$\sin(30^{\circ})=2\sin(15^{\circ})\cos(15^{\circ})$$
and $$\cos^2(x)+\sin^2(x)=1$$


How to export multiple JPG with one layer changing using Illustrator

Question: Im trying to make a set of certificates and I have each name on a different layer. I want to export each certificate with a deferent name with the template being the same.
Comment: Hi Naveen! Have you tried anything on your own yet that didn't work? Depending on the amount of names you have to do this for, you could do it manually (by turning on / off layers and then saving), or if you have tons of names to do this for you could write an action or script to do this. If you could edit your question to include some of these additional details it will help people answer your question.
Answer:
This can be done by scripting. I dont have time to whip up an example right now but you can use the script in how-to-do-animation-frame-pngs as a starting point. It would be quite easy to make it recognize locked layers as nontogglable entities for example.
Though it may be easier to use  text variables instead a bunch of layers. See adding-individual-guest-names-to-a-wedding-invitation-in-illustrator for more info on how to do this. In either case you can toggle layers too with variables so same approach can be used with layers too its jut unnessecery work but there may be some reasons to do this such as having different fonts etc.
it is possible to use a action to toggle layer save hide layer move selection upp by one layer. But this would be a bit tedious so I wouldnt use it especially since scripting takes less time with a good scaffold as a startingpoint, but YMMV.
Comment: Tried the 2nd option and it's just what I wanted. thanks @joojaa
Comment: @werlox you should consider accepting the answer if it answers your question. That helps the site work better.
Comment: i did. notification shows saying 'Votes cast by those with less than 15 reputation are recorded, but do not change the publicly displayed post score'
Comment: @werlox not upvote, accept is the icon below that has a checkmark. you can allways accept your own questions.
Comment: oh sorry, it's done (:
Answer: What I would do is use InDesign. Create a master page with the certificate and a master column just to fit the names in. Create as many pages as names. Auto-flow the names. Your Done. InDesign is great for variable printing.
Answer: I don't think there is currently a tool for illustrator to systematically turn on and off a series of layers and export them individually as you envision.
I would suggest duplicating the Artboard as many times as you have different names. Then turn on one name per artboard.
At that point you would be able to export the Artboards as jpgs in a batch.


existence of an analytic function in unit disk

Question: Does there exists an analytic function $f$ in unit disk such that $f(-\frac{1}{2})=3$, $f(n^{-2})=5$ for $n\ge 2$.
 i am not able to solve any help will be appreciated.
Answer: By continuity, $f(0)=5$. But then the zero at $z=0$ of the function $f(z)-5$ is not isolated. We conclude $f(z)-5=0$
Answer: Suppose that , $f(z)$ is analytic in the unit disc.
Consider $g(z)=f(z)-5$. Then $g\left(\frac{1}{n^2}\right)=f\left(\frac{1}{n^2}\right)-5=0$.
So, the set of all zeros of $f(z)$ , $\left\{\frac{1}{n^2}:n\in \mathbb N\right\}$ has a limit point $0$ in the unit disc.
So, by Identity theorem $g$ is identically $0$. Then $f(z)=5$.
Now, $f(-1/2)=5$, which as a contradiction.
Hence there are no such function satisfying the given conditions.


How is generator output voltage kept constant?

Question: I read that if we increase the load at the terminals of a generator, the current driven from the generator will increase which will slow down the generator. But for this to happen the generator should output constant voltage. How does it achieved? And if there is no voltage regulation (just a generator and we increase the load step by step), what would happen?
Answer: I am going to assume you are referring to wound rotor Synchronous generators.
There are two main aspects to consider when you are dealing with such generators.

Field control
Damper Bars/Windings

To generate electricity the shaft obviously has to be rotated but there also needs to be some form of field on the rotor. This is provided by either brushes or a brushless (rotating diode) arrangement. This produces a DC excitation field on the rotor that can be controlled from the stators mechanical frame of reference (ie non-rotating)
What method is chosen is a system specific consideration but both provide means to control the rotor flux. Such a controlling system can be referred to as a Generator Control Unit (GCU)
A certain rotor field for a given rotor speed will produce a certain magnitude sinus waveforms at the stator terminals (the frequency of that is related to the speed of rotor rotation & the number of pole pairs on the stator).
The terminal voltage can thus be controlled via the strength of the excitation field. By providing a closed-loop controller that measures the terminal voltage w.r.t. a desired value, the terminal voltage can be maintained across the load range simply by varying the rotor's excitation field strength.
Damper bars/windings are a secondary means to help facilitate the terminal regulation. They are buried deep within the stator winding slots and essentially they aim to short-circuit the magnetic circuit in the event of high di/dt which may occur during load applying or shedding. This help to mitigate massive terminal over-voltage (load-shedding) or machine stalling (load applying) until the GCU control loop can "catch up"
Comment: lest say we have a simple induction generator(no excitaiton flux) rotating from a constant wind force. and we have no voltage regulation. and it is rotating with a rated rpm (btw i'm not sure if generators have rated rpm like motors), and outputs V volts when we connect a load with R resistance to the ends and current I flows. What happens if  we increase or decrease the load R here? Will the voltage regulate? Will the current increase? Will the generator slow down?
Comment: An induction generator would have to be connected to a grid so that some rotor flux could be induced, no? And in that case the stiffness of the grid helps with load changes.
Comment: motors<>generators... they are all "electrical machines" they can all operate as both... Induction machines acting as generators are a bit harder... They do not generate torque at sync speed so you would need to rotate the rotor above your desired speed. The only way to regulate it (once the caps are in place) is via the speed of the rotor w.r.t. terminal voltage in a crude V/f control
Comment: so voltage will not regulate? what will happen if I increase the R in that case? will the generator slow down? will the output voltage decrease? could you answer these like yes no?
Comment: It can be regulated but exactly how comes downto whether it is a squirrel-cage rotor, doubly-fed induction machine etc... Each machine topology comes with its own ... quirks as to how to interface to it. This is why sync machines are prefered for generators, they are very simple
Comment: so you dont have an answer
Comment: I have answered for the given information but this is getting off-point.
Answer: An induction wind turbine generator has to be connected to a grid to generate power. (It could be self excited with a capacitor bank, but that's beyond the scope of this answer.)
Below a speed which would generate useful power, a control system cuts the turbine off so it doesn't run as a motor.  Above that range it will run near synchronous speed with the slip being proportional to the torque produced by the wind.  Higher electrical loads will increase the torque load on the blades causing some slowing. The grid usually will supply most of the load and buffers the effects of varying wind speed.
In an engine driven generator the mechanical engine speed is usually regulated so that loads that would ordinarily slow the machine down only do so for the transient case while the control system brings the motor back to nominal speed.
It's also possible to take the variable speed/voltage output of a non grid-connected synchronous machine (wind turbine for example), rectify it to DC and invert it to something that can be grid attached, or convert it to charge batteries.
Other schemes are possible, such as the one described by JonRB above.
Comment: what kind of generator would you suggest for a very small application which will store energy as dc? so that i can ask the questions more detailed.
Comment: I would think maybe a permanent magnet synchronous machine might make sense, you could use a BLDC motor as a generator.  Then you could convert to DC with a 3-phase bridge and DC-DC from there, as required.


Does a wider magnet mean less flux density?

Question: I was using an online magnet strength calculator when I halved the diameter of the theoretical N52 magnet. The dimensions went from 32mm in diameter and 3mm thick, to 16mm in diameter and 3mm thick. The surface field heightened from 1,364 Gauss to 2,598 Gauss instead of lowering (which is what I would expect). Why is this?
Answer: Yes, all other things being equal, a smaller diameter magnet has a higher surface Gauss value.
Explaining why could go all the way into the mysterious depths of magnet physics, so I'll just give the first couple of layers.
A theoretical N52 magnet has a "Maximum Energy Product" (peak product of magnetic flux density and magnetic field strength) of 52 MGOe (million Gauss Oersted). The resulting surface Gauss (magnetic flux density) in an open circuit (eg. when the magnetic is in free space) depends on the length to diameter ratio. Roughly speaking, that's because the magnetic field lines spread out in order to meet the opposite pole. The longer the magnet the tighter the lines need to be (higher flux) but the wider the magnet the less tight the lines need to be (lower flux).
So by decreasing the diameter of a magnet with the same MGOe rating, you concentrate the field into a smaller region and register a higher Gauss value at the surface.
This is really tricky stuff that I've only scratched the surface of, so there's some great further reading here.
Comment: Does that mean that a magnet with spaces in between would have a greater strength than a magnet with more mass? Or how about 4 different magnets, but instead of putting them together spacing them apart by about a millimeter? A good example would be in an alternator for the following question. Would it be better to multiple smaller and spaced out magnets for the extra flux strength and less area or would it be better to have one whole magnet? Great explanation by the way.


How to setup a IIS6 webserver for hosting development projects?

Question: I am looking for a way to configuire a development webserver. My main goal is to be able to provide internal personel with access to these development websites for review and testing? I'm not sure if its possible to configuire something that would allow for the existence of urls such as dev.someprojectname.com that could only be accessed interanlly. I'm not sure if I need to have entries put into a domain controller or if there is a simple way of implementing this.
Answer: It can be configured just like any other IIS web server, except use a domain name local to your network (dev.mycompany.local) or some other DNS name that exists only for your local network.  If it needs to be accessible from the outside, use a standard domain name that will resolve externally, and disable anonymous access to the site in the IIS web site properties (use Integrated Windows authentication if possible).  Then, your developers can use their domain accounts and passwords to authenticate when they first access a dev site and use it normally from that point forward.
Comment: Thank you for you suggestion I will consult with our network admin and see about implementing this as a possible solution.
Comment: Note that "some...DNS name that exists only for your local network" is not a security solution - if the IP address is accessible, it *will* be found, DNS or no. AAMOF, a standard domain name that resolves to a non-routable/firewalled address works just as well.
.local is to avoid DNS conflicts, not for security.
Comment: Good comment Mark, I was going on the assumption that if it's a server on the local network with a local domain name, it would likely be on an internal IP and not routable to the outside world.  If they used a public DNS name, then it would point to an external public address and have port forwarding on the NAT router to bring the requests into the network.
Answer: It's just like a production web server, only with different security. If you want it internal only (meaning, you must be on the internal LAN to access it) give it a private IP address that's not accessible from the outside (or block it at the firewall).
If you'd like to expose it more than that, you can use IIS authentication - but I don't recommend it. Dev sites are likely misconfigured, with wide open security holes.
So, if you're going to expose it outside of your trusted LAN, stick a reverse proxy server in front. The proxy is a production server, and handles authentication (with some combination of ip address, username/password, and/or client cert). The dev server still sits on a private IP address, and the firewall only lets the proxy server access it.
Answer: If it's for local use only and you can't get entries added to DNS you and your colleagues can also have a play with your hosts file to configure some new uris.


How many Ethers has the Ethereum Switzerland GmbH?

Question: As I understand, the EthSuisse founded Ethereum in 2014. How many Ether do they have mined for themselves and how many are in the community?
Answer: For those who haven't seen it, the PDF of the Terms and Conditions of the Ethereum Genesis Sale can be found here. (See the parent pdf directory for more gems.)
On page 8 of the document:

In addition to the Genesis Sale Quantity of ETH, the pre-mining
  process will create and place a second pool of ETH in the Genesis
  Block. This second pool of ETH will be directly allocated to early
  contributors who have worked to develop the ideas, implementations,
  and supporting structures of the Ethereum project up to the time of
  the Genesis Sale. The size of this pool will be 9.9% of Genesis Sale
  Quantity of ETH.

I believe the initial sale raised the equivalent of $18 million (i.e. the Genesis Sale Quantity), but I can't immediately find a source, so I'm happy to be corrected.
At the time of the sale, EthSuisse was a GmbH (Gesellschaft mit beschränkter Haftung) - i.e. a company with legal liability, and therefore a legal entity governed by the terms and conditions, which made it more difficult to run off with the money. The company was liquidated, as per plan, and as laid out in the above document, after the Genesis block was created.
I'm unsure how to determine how much the Ethereum Foundation currently have, and how this relates to the individuals who were rewarded as members of EthSuisse. Someone closer to the Foundation might know more. (Note: It's been suggested that this is their account, though I don't know if this has been formally confirmed.)
Comment: That would be 353,618.4 Ether


Find an equation of the tangent line to the curve

Question:
Find an equation of the tangent line to the curve $2·(x^2+y^2)^2=25·(x^2−y^2)$ at the point
  $(3,1)$.

Any hints?
Comment: You can use implicit derivation
Comment: $y^{'\:}=-\frac{x\left(4y^2+4x^2-25\right)}{y\left(4y^2+4x^2+25\right)}$
The what do I do?
Answer: The more general way to solve this type of problem is with implicit differentiation:
We have $2(x^2+y^2)^2=25(x^2-y^2)$.  Differentiating both sides w.r.t. $x$, we get: $$4(x^2+y^2)(2x+2yy')=50x-50yy'$$ $$\implies (8(x^2+y^2)y+50y)y'=50x-4(x^2+y^2)\cdot 2x$$ $$\implies y'=\frac {50x-8x^3-8xy^2}{8x^2y+8y^3+50y}$$ $$\implies y'=-\frac{x(4x^2+4y^2-25)}{y(4x^2+4y^2+25}$$
Because we know that derivatives are just the slopes of tangent lines to graphs, we know that the slope of this implicit function at point $(3,1)$ is $y'|_{(3,1)}=-\frac{(3)(4(9)+4(1)-25)}{(1)(4(9)+4(1)+25)}=-\frac{9}{13}$.
We then just plug in that slope and point into the point-slope equation of a line: $$y-y_0=m(x-x_0)$$ and we have the answer.
Answer: Expanding:
$$4x^2+4y^2 = 25x^2-25y^2,$$
$$29y^2=21x^2.$$
Note that we can take the positive root since the point of interest is in the first quadrant.
$$y=\sqrt{\frac{21x^2}{29}}.$$
From here you are able to solve the problem.


Best way to import users, post and categories from an external database

Question: I need to migrate an existing website to WordPress. This website already has a basic database containing users and posts (with a category), but it also has a high number of records so it's not possible to do it manually.
What is the best way to import them into my WordPress database? Should I try to export the old one into a CVS file or something similar?
Comment: Although your target is WordPress, this is really more of an ETL question than a WordPress question. You might get a better answer at the dba or stackoverflow.com
Answer: Unless there is a core Wordpress import filter available for your CMS ( see http://codex.wordpress.org/Importing_Content ) or a plugin for a CMS not covered by core WP ( see http://wordpress.org/extend/plugins/search.php?q=import ), or a Google search for your database schema doesn't reveal anything, you need to roll your own importer.
The best way is to write a MySQL query that will take your current data and move it into the Wordpress database structure. That can be complex, but in the end, it's the most efficient and accurate method.
But you can also try exporting from the database using phpmyadmin into CSV and then working with that file with Excel or text editors to get the content into the correct Wordpress table schema and import that CSV with phpmyadmin ( see http://codex.wordpress.org/Database_Description or try a CSV import plugin http://wordpress.org/extend/plugins/search.php?q=import+CSV ). That's obviously less MySQL intensive, if you're not that great with queries.
Or you can try building and then importing a WXR file, WP's special import format used for moving content between Wordpress installs. Export a few posts and pages from a test Wordpress site to get a sample WXR file to determine the format ( see http://codex.wordpress.org/Tools_Export_Screen ). And then take a text export of your database and "massage" it into a WXR file.
Another idea is to set up an RSS feed for your site and import that way; see http://codex.wordpress.org/Importing_Content#Importing_from_an_RSS_feed But that won't get users or categories, only posts.
Answer: You can write a simple php script to query your database, pull out the relevant data, and then use wp_insert_post to create the posts automatically in wordpress (http://codex.wordpress.org/Function_Reference/wp_insert_post). You'll need to have included wp-blog-header.php in your script to use wp_insert_post.
Answer: What about "simply" writing a SQL script that populates the wp_posts, wp_users,... wordpress tables with the contents of your current ones?
Not for your specific CMS but you´ll be able to find example scripts for other CMS that you could use as starting point