Accessing external HDD on different Windows computers with the same path

Question: I have a external HDD and have a folder in it called icons\ which stores all the custom icons (yes, I'm nostalgic!) for the different folders on my drive. But when I open my hard-drive on a different system (dealing only w/ Windows here), it doesn't show the icons I chose. I guess this is b'coz the paths change. How do I fix this?
[Edit:] After thinking this through, I'm guessing the reason this might not be possible is that every-where, the hard-drive won't get assigned the same letter. For example: On my desktop, it might be F:\ and on my laptop it might be G:\. And the letter would also change if you connected the HDD to a different USB port. How can I fix this? Use some system variable to know which drive the HDD is connected to?
[Edit:] Somebody suggested using relative paths -- e.g., icons\my_icon.ico -- but that didn't work :(
[Edit:] I found the environment variables that I was talking about. What if I used %cd% for the path of the current directory?
Answer: Use relative paths (eg \icons\my_icon.ico)


Can orbitals in a molecule be occupied via excitation like they can in atomic orbitals?

Question: I am facing a conundrum in the way I am viewing molecule orbitals due to the existence of excited states. What I wanted to know is, since atomic orbitals can exist in excited states (i.e. you get hydrogen accessing states outside the 1s orbital and such when a high-enough energy photon is used), is this the case with molecular orbitals, where 'technically' many more states exist than shown on a molecular orbital diagram? I mean, they tend to only show the valence and core electrons, but not past that, hence the question. For example, could methane, that only whose MO diagram only shows molecular orbitals composed of 1s, 2s, and 2p orbitals, have an electronic transition that occupies a 3s orbital? And if so, how would that occur? Would it occupy one particular atom or be 'spread out' like most electrons in MO theory?
Sorry, long question, but something that is bugging me for some strange reason.
Comment: Methane does not exactly _have_ 1s, 2s, and 2p orbitals. Instead, it has molecular orbitals _composed of_ those. And yes, any molecule has multiple excited states that can be reached.
Comment: Okay, fixed that. Tend to make mistakes in terminology when I write in a rush.
Answer: Most of what applies for atomic orbitals in atoms can be transferred to molecular orbitals in molecules. This includes that electrons can be excited to higher lying orbitals, creating excited configurations.
Also, just as for the hydrogen atom, there are in principle infinitely many orbitals available. They are simply truncated since the higher lying ones are less important (and for numeric reasons).
Comment: Thanks for the answer. In the case of virtual orbitals, would the 'cut-off' for 'important' orbitals tend to be set really only to those that aren't outside your typical molecular orbital diagram for that reason? I mean, of course excluding the addition of things like polarization basis sets and such. That is actually why I got the question actually - was reading about post-HF methods and was wondering about what they consider as the "full CI" if there are technically infinite states... guessing it must just be the 'important ones' i.e. valance electrons, maybe some rare Rydberg ones, yes?
Comment: Usually the cutoff includes all valence orbitals (or what you can form fram all valence AOs). Things like polarization functions are about the AO basis. But also influences the MOs, since you get as many MOs as AOs are supplied. Which also means FCI depends in the AO basis set. It can only consider as many MOs as are available.
Comment: I guess I would like to ask one more addition to what we are talking about, if you don't mind - do we know the defined shapes of these molecular orbitals like we do for, say, the ones generally shown in MO diagrams? Or is it a bit more abstract since we are talking about more complex mixtures of AOs?
Comment: If am not sure if I get your question right, but occupied orbitals can be quite intuitive, e.g. core orbitals which are al,pst identical to AOs, or bonding MOs where you can relate the number of nodes to the bonding character. These orbitals which are "generally shown in MO diagrams" do come somewhere from ;) However, virtual orbitals get more abstract and occasionally change with the AO basis set. Maybe this is worth a separate, new question ...
Answer: Customarily, LCAO molecular orbital schemes are drawn using the atomic orbitals of the valence shell, ignoring both core orbitals and most higher-shell orbitals. For example:

the MO scheme of methane will contain the $\mathrm{1s}$ orbitals of the hydrogens and the $\mathrm{2s}$ and $\mathrm{2p}$ orbitals of carbon because these correspond to the valence shell
the MO scheme of $\ce{CO2}$ will use the $\mathrm{2s}$ and $\mathrm{2p}$ orbitals of both carbon and oxygen and ignore the $\mathrm{1s}$ core orbitals as well as all higher orbitals
the MO scheme of $\ce{HOCl}$ will use hydrogen's $\mathrm{1s}$ orbital, oxygen's $\mathrm{2s}$ and $\mathrm{2p}$ orbitals and chlorine's $\mathrm{3s}$ and $\mathrm{3p}$ orbitals (see also the next example)
when constructing the MO scheme of hexafluoridoferrate(III), the $\mathrm{2s}$ and $\mathrm{2p}$ orbitals of fluorine are used while the $\mathrm{3d, 4s}$ and $\mathrm{4p}$ orbitals are used — these together correspond to the valence shell.

For each atomic orbital entered into the equation the solution must include exactly one molecular orbital. So having two orbitals interact will always result in a more bonding orbital (the same phases overlap) and a more antibonding orbital (opposite phases overlap). Thus, we will end up with $8, 12, 9$ and $33$ three orbitals respectively for the examples above. This already provides us with ample orbitals to excite electrons into; in the methane case, these would correspond to four $\unicode{x3c3}^*$ orbitals, three of which are degenerate due to symmetry.
Nothing is stopping us from including the core orbitals in the calculation or additional unoccupied atomic orbitals. In fact, quantum chemistry programs often include these orbitals in the calculations. The core orbitals do no harm (you will end up with a set of MOs at very low energy that are basically confined to the nuclei; linearcombining these will lead to exactly the set of core orbitals you threw into the equation). The virtual orbitals are actually typically used as polarisation functions to provide a better final result.
Including the virtual atomic orbitals will merely create more virtual molecular orbitals at the top of the energy scale. These can indeed be accessed by excitation with photons of appropriate wavelengths — in theory. In practice, they are rather far removed and photons arriving with appropriate wavelengths will also be energetic enough to do much more damage, e.g. ionise electrons completely. As an example, the electrons in molecular orbitals of $\ce{[FeF6]^3-}$ corresponding approximately to the ligands' p orbitals already require ultraviolet photons to even be excited to the $\mathrm{t_{2g}}$ orbitals. Imagine how much energy would be needed to excite a $\mathrm{t_{2g}}$ electron to levels formed with $\mathrm{3s}(\ce{F})$ or $\mathrm{5s}(\ce{Fe})$ orbitals!


How to export amodel from blender with textures and animations to use the model in Irrlicht?

Question: I am creating a small game using the Irrlicht engine. I have created a human model using MakeHuman and I have imported it in Blender. I am a total beginner to 3D I have created some basic animations in the model. MakeHuman already applied textures to the model, so I think It does not need to be done again. How to export the human model with textures and animations to use it in Irrlicht?
Answer: According to the Irrlicht Feature page, the engine supports the follow for fomats and texture types.

Direct import of common mesh file formats: Maya (.obj), 3DStudio (.3ds), COLLADA (.dae), Blitz3D (.b3d), Milkshape (.ms3d), Quake 3 levels (.bsp), Quake2 models (.md2), Microsoft DirectX (.X)… [more]
Direct import of Textures: Windows Bitmap (.bmp), Portable Network Graphics (.png), Adobe Photoshop (.psd), JPEG File Interchange Format (.jpg), Truevision Targa (.tga), ZSoft Painbrush (.pcx)… [more]

In order to export the mesh, you need to select the various components, then from the File -> Export menu you have a variety of options to choose from. See image.
After you have it exported then its a case of doing the engine side stuff.
Comment: It looks like Irrlicht does not support animations for formats like COLLADA / DAE: http://irrlicht.sourceforge.net/?page_id=45#supportedformats http://irrlicht.sourceforge.net/forum/viewtopic.php?t=21068
It would be nice to have explanations on how to export to a format that supports animations, like OP asked, for example exporting to a B3D file (which I did not see available in Blender export by default).


Why do many international organizations have their headquarters in Geneva?

Question: Geneva was the headquarters of League of Nations even though it did not participate in WWI. It has the UNOG from 1946 though Switzerland has not joined UN till 2002. It was the headquarters of OPEC till 1965 though Switzerland is not one of the oil producing countries. In addition to the above, Geneva is the headquarters for a number of International organizations. Why do many International organizations have their headquarters in Geneva?
Comment: At some point, it's likely because that's where other international organizations are.
Comment: I did not know where to post the question, but I thought Politics is somewhat related. I know the tags are not related. As I am new to stack exchange I don't know what fits and what doesn't.
Answer: Imagine your home country got invaded by the fictional superpower of Elbonia. The Elbonian soldiers burned down your house, abducted and/or killed several of your friends and relatives and kicked your dog. Now a self-proclaimed humanitarian help organization with their headquarter in Elbonia comes along and says: "Yeah, very bad what our government did to you, but we are here to help you. We can bring you to a refugee camp where you receive totally non-poisoned food and completely non-experimental medical care and will certainly not be tortured for information. You just need to trust us". Would you come along?
Switzerland is a country which has long maintained a policy of neutrality and non-involvement in international affairs. For almost 500 years and counting Switzerland refused membership in any military alliance, and is also wary of any civil treaties. It is not an EU member despite its geographic position right in the center of Europe. Until 2002 Switzerland wasn't even a member of the United Nations.
That means an organization based in Switzerland can deny that their actions are influenced by the interests of the government of the country they reside in.
As the second-largest city in the country, Geneva provides a good infrastructure for an international organization.
Comment: Is the use of [Elbonia](https://dilbert.com/search_results?terms=Elbonia) here intentional?
Comment: @Chipster I used to be an avid reader of the Dilbert comics and used to use Elbonia as a stand-in fictional country in my answers. I stopped doing that after I found out that the creator also has a blog where he publishes strong political opinions. I don't want to give the impression that I share or oppose his views. Nowadays I prefer to use the fictional countries from the game [Papers, Please](https://en.wikipedia.org/wiki/Papers,_Please) instead.
Comment: "For almost 500 years...": For only the last 208 of those years was Geneva a part of Switzerland.
Answer: Historically, Geneva has the condition of being in Switzerland, which is a country where international treaties are signed in the modern history. After the Napoleonic wars and joined the Helvetic Confederation, here celebrated most of the international treaties, which have huge impact in the Western World; Starting in 1863 when Henri Dunant founded the International Red Cross (ICRC) and still having an office in the city.
They were local to the first Geneva Convention, the Hague Conventions of 1899 and 1907, the Third Geneva Convention of 1929 among others which are historically and juridically important. Also, Geneva was the place where the League of Nations was established; when the League didn't work, they used the Geneva infrastructure to build the United Nations in 1946.
Interesting fact is that most of the recognized international NGOs has office over there and where it held the World Economic Forum or tweet it #WEF for more information.
Comment: You just iterated that Geneva is the center of international treaties and NGOs, but you are not really providing an explanation *why*.
Answer: First and foremost, Switzerland has a long tradition of strict neutrality, which helps diplomacy. Plus, it has gorgeous landscapes, right in the middle of Europe (transportations, of course, weren't as efficient as today). It's also French speaking and French was the language of the elite and diplomacy in the 19th century. Many aristocrats went to Switzerland on holiday or sent their kids there to private schools.
In general, it's also difficult for large and powerful countries to agree to grant the seat or leadership of any international organisation to each other (the UN in New York being one major exception). See for example the citizenship of the UN secretaries general, the seat of the European Union, etc.
Switzerland was therefore able to attract some of the earliest modern international organisations, like the Universal Postal Union and International Telecommunication Union. Furthermore, the Red Cross movement was initiated by a citizen of Geneva.
Add to that the fact that Europe was still much more influential than it is today and that Switzerland did not participate in the First World War and you can see why it was well-positioned to attract the seat of the League of Nations (incidentally, another small non-belligerant, the Netherlands, also hosts a number of international organisations). And many of the organisations based in Geneva are now part of the "UN system", which succeeded the League of Nations.
The current situation kind of follows from this history. There is no obvious reasons why international organisations would choose Geneva today but the infrastructure, workforce, etc. is in place and it would be very costly to relocate all this.
And Switzerland has always been keen on protecting this heritage and punching above its weight diplomatically. It frequently offers itself as a mediator between warring countries, acting as a protecting power and hosting foreign interest sections in Swiss embassies everywhere. (Here as well there is another small neutral country playing a similar role: Sweden.)
The same dynamic would also seem to apply to OPEC. It couldn't very well be hosted in one of the major production countries and many of the smaller ones are unstable. In a continuation of its 19th century tradition, the Geneva area is still a common destination for rich and powerful people, e.g. from the Middle East. Many heads of state have villas on the lake shore or go to Geneva hospital to get medical treatment. I don't quite know why OPEC moved but its new seat (Vienna) is similar in many ways (secondary UN seat, small neutral country – albeit for a much shorter time than Switzerland).
Answer: This is possibly exactly because Switzerland was a country that was rarely participating in the wars. That's why people hold money in Swiss banks and put international organizations there.
Comment: @MikelUrkia Switzerland is NOT a tax-heaven for the regular citizens like me. We **do** pay heavy taxes just like everyone else. Only very rich people and very large companies get advantages - and this is highly controverted but the right wing parties manages to maintain the *statu quo*.
Comment: @MikelUrkia Bank secrecy was more important than taxes. Taxes for regular people are not particularly low, there is no easy way to pay low taxes for individuals without actually living there for most of the year, and company taxes are only interesting in very few places in Switzerland (e.g. Zug). But the thing is that because Swiss banks were extremely discrete and it was extremely hard for the authorities in other countries to obtain information, you could easily do something illegal in your country, park your money in Switzerland and evade detection. It's becoming less and less true.
Comment: I'd say Switzerland's neutrality has not much to do with people holding its money there. I'd say it is more a matter of low interests and economical benefits. Do not forget that Switzerland is a fiscal tax-haven.
Comment: @Relaxed I totally agree with your statements. Like you say in your last sentence, the banking secrecy is becoming less and less true. Leaks like the Falciani list demonstrates this.
Comment: @Bregalad you have per-citizen pension which is actually "negative tax".
Comment: @Bregalad I agree with you. In this type of situations, we always talk about rich and powerful people, rather than regular citizens. We [regular citizens] usually get chewed up with taxes while they are not...


Merge 2 Pointlayers with same coordinates but different attributes in QGIS?

Question: I have two layers with points who have exactly the same coordinates but different attribute fields. I would like to merge the tow layers so that I only have one point at each location who has the attributes from both layers.
I have the feeling that this should be very easy but I just cannot do it and cannot find any expalanation.
Answer: You can use the Join attributes by location tool from the toolbar (Vector > Data Management Tools > Join attributes by location).
Select the Keep all records option to make sure the output layer receives all attributes related to each specific point:

Hope this helps!


If lost in the wilderness, what is the first thing I should do?

Question: If I get lost in the wilderness, what is the very first thing I should do?
Comment: This question needs to be a bit more specific. There's a big difference between walking your dog in the woods and getting disoriented and being in a plane crash in the middle of nowhere. Climate matters. Forest? Dry grasses? Desert? Water? Snow?
Comment: I feel this is such an important question, with such a wide range of answers, it should perhaps be a wiki.
Comment: It depends how lost you are, how far away from a road you are, how long you can last in the heat/cold, how much water you have and need, whether you have a communications device, whether people will be looking for you, and etc. In other words, you will need to think things through logically.
Comment: Stop moving. Chances are you'll only run away further from whoever is going to look after you.
Comment: First: establish *how* lost you are.  "I'm either five or nine miles upstream from the trailhead" (my situation) requires different measures than "I don't know which river valley I'm in" (the situation of the dirt-biker I flagged down for directions).
Answer: The VERY FIRST thing you need to do is to not panic.  Sit down for a minute or two and let your mind catch up to the fact you are lost.  Now, take out your map, compass, gps, or whatever and try to find your way back to where you DID know where you were.
If you can't figure out where the trail should be and you need to bushwhack, find a bit of a clearing, take bearings to nearby landmarks, and draw on your map (or use sticks if they are straight) the bearing from whatever landmark.  Try to get 3 or more landmarks, the lines will form either something resembling a polygon, or (if everything works out right) something resembling an asterisk.  You are either in the polygon, or at the intersection of the sticks.  Once you know where (or about where) you are, put a small stone on your map and then figure out which way to go.
If you don't have a map, or your GPS died, or you don't know how to take a bearing, one of the tricks I was taught in Wilderness Survival Merit Badge back in the Stone Age, walk downhill until you find a creek/stream/river.  Follow the river's current, and likely you will cross a road.  Once you have found a road (if it looks somewhat well travelled), wait for assistance.  Otherwise decide whether to follow the river or the road until you DO get to a place where civilization extends its reach.
Oh, and above all, DON'T PANIC.  If you panic or feel like you may start, stop doing whatever it is you are doing and calm down.  If you keep your wits you are much more likely to survive the encounter.
Comment: "A human can live three minutes without air, three days without water and three weeks without food — but three second of panic can kill you." -- from http://www.katterat.com/Courses.html
Comment: I can't agree more with your first statement.  I can remember the first time I really 'felt' lost.  My heart rate went up immediately as the adrenaline dumped into my bloodstream.   My mind just raced.  Thankfully, I sat down and just breathed and started thinking through the situation.  Once I calmed down, things rapidly became better and my cognitive ability slowly returned.   Being calm is the key to success.
Answer: Assuming you told people where you were going and you don't have PLB with you, you should start building camp. Construct distress signal discussed here: How can I signal for help in the wilderness?

Don't panic
Get busy making your camp
Look for sources of water
Construct distress signals
Make traps, set up fishing lines, gather plant food.
Gradually map out your area you are in by hiking from your camp.

Always remember to leave an imprint of your boot in your car (assuming you arrived with a car, if not then at home, and make sure people close to you know about it), together with your notes for the trip you are planing to take.
@Pulsehead's answer is right, too, I just thought I'd offer an alternative. I guess the choice depends on how far from civilization you are and if you are injured.
Comment: This is overly simplistic. Subzero temps, high above bush line, rising river levels, storm imminent, wild animals.... There are lots of times making camp would be a really bad idea. Why make setup for the long haul before establishing how lost you are?
Comment: I think in your second point (get busy making your camp) you should stress how important it is to stay put. Otherwise, you'll always be a step ahead of Search and Rescue. Countless stories of people being lost in the woods for days all revolve around the fact that they didn't stop moving...
Comment: I like the imprint of you boot idea. That's smart.
Answer: A neat little (recursive) acronym i learned in my survival education in the army is STOP (freely translated from Swedish):

Stop - Don't panic,
Think - Consider your situation, and do not deny the fact that you are lost,
Orientate - Look at and get familiar with your surroundings,
Plan - Make a plan on how to solve your problem.

This is, of course, not a comprehensive, exact answer, but a nice to have mnemonic.
Comment: This is the exact answer, because every situation is different, anything more precise will fail to get you out of trouble. Best advise I can add is to Step 1 - do nothing for 15 minutes - unless conditions dictate it for survival. (Most people will be so busy trying to do nothing, they have done most of the thinking by the end of the 15....).
Answer: Yes, first stop to not make things worse, take a deep breath, and collect your thoughts.  After that it depends a lot on the situation.  I don't like most of the other answers because they assumed certain situations without stating their assumptions.
What you should do next depends on a lot of things, so much so that giving any simple answer is impossible.  Factors that matter include:
How far out are you?  Did you go into a local conservation area in town and don't remember which trail takes you back to the car, or are you alone in a remote area on a solo day hike or longer?
How did you get lost?  You weren't sure of which way to go at that last intesection a 1/2 mile back, or you've been following what you thought was the right trail for hours and now its getting late and the trail has petered out?
What is the weather like?
What do you have with you to survive?
Are you completely off a trail, or just don't know which trail you are on? Or know the trail, just not where you are along it?
How easy is it to navigate?  Are you above tree line and can see for miles, or in dense forest that all looks the same in either direction?  Are you on a trail you can follow, even if you don't know where it goes?
What navigational aids do you have with you?  A compass?  GPS?  Watch?  Can you see the direction to the sun?  Do you have just a trail map?  A topo map?  No map and just a general mental picture?  You're totally clueless and don't even have that?

There are various levels of being "lost".  The usual definition is you don't know where you are, but clearly you have some idea.  Most people use the term to mean that they don't know which direction to proceed in, which is quite different.  Or do you have two or more choices, just don't know which one is the shortest or otherwise best way back?
Without a clearer description of what predicament you actually mean, it is impossible to give responsible advice.
That all aside, a general rule when truly lost (not knowing where you are) is to always keep in mind what your location is bounded by that you can identify.  Start with as large a area as it takes, then think carefully about how you can narrow this down.  For example, you may know there is a north-south road to your east, a river to the west, a cliff you'd fall off of to the south, etc.  Eventually you can identify the area you are in with something bouding it all around that you would notice if you came accross it.  Whatever you do, keep those bounds in mind.
Answer: I was always told to make a cup of tea. Doing so gives you time to think, and involves finding firewood and many of the materials you'll need if things go bad.
On the other hand, i'm British so given enough time to tie a shoe lace we've usually got a brew on.
Answer:
Find water
Find food
Make shelter
Make fire
In the morning hike until find salvation
Comment: Compared to the other questions this is rather brief and has zero punctuation, can you improve it?
Comment: @Wills better now it's a proper list I agree, I was not the downvoter :)
Comment: I see no problem with that answer. It is short and required some formatting (which was very easily done), but still it is OK.
Comment: if you are lost at 9am in the morning on a nice day, your answer would not be the first thing to do.
Comment: Well it's not really about the first thing to do, it's a list of things to do (finding food is certainly very far down in any list, in many a survival situation it's even a bad thing to do at all).


What Does Hinduism Say About Ghosts?

Question: Does Hinduism say anything about ghosts? Like why they may be stuck here, if it's really the jiva or something else like it?
Answer: Yes, Hinduism says many things about ghosts. The Garuda Purana has good descriptions about it of which some are as below to answer your question:
When a person dies then he becomes a preta (Ghost). Generally this phase is temporary and as soon as the funeral rites are over, the preta state is over and the jiva then gets the status of Pitru (manes or forefathers). However, if the funeral rites are not duly performed or the death and actions of the person is not good then he may get stuck in the limbo or preta phase:

pāpakarmaratā ye vai pūrvakarmavaśānugāḥ
jāyante te mṛtāḥ pretāstāñchṛṇuṣva vadāmyaham [GP - 2.22.3]
Meaning
He who is indulged in sinful activities goes to become a preta after death; that I am telling you please listen.
svaiḥ svaistu karmabhiḥ prāptaṃ pretatvaṃ hi dvijottama
paradroharatāḥ sarve pāpamṛtyuvaśaṃ gatāḥ [GP - 2.22.33]
Meaning
O best among the twice-borns (dvijottama), one certainly attains the state of preta due to ones own actions. All those who are engaged in offence or enmity (droha) toward others, under the influence of sin and death go  on to be come ghosts.

That chapter then describes many such activities doing which one goes into the preta state for certain. Basically if one commits sins, kills other, causes pain to elders, brother, sister etc. without any reason, who has forsaken rememberance of Vishnu, who doesn't perform fire sacrifices, etc. obtains the state of pretatva (ghost hood).
Comment: You included details here that you didn't include in your previous answer to what was essentially the same question: http://hinduism.stackexchange.com/a/2052/36 Why don't you delete this answer, copy and paste these details into that answer, and then vote to close this question as a duplicate?
Comment: @KeshavSrinivasan I answered the question because "stuck here" triggered some thoughts in my mind and I remembered the things I wanted to mention. It didn't occur to me at that time while answering the other question. But people who think negative may take I answered it for reasons like reputation or something, and also the question is essentially the same without the stuck thing,  So I am adding these info over there.

What Does Hinduism Say About Ghosts?


What are iron stars?

Question: I have a question about iron stars. I was fascinated about the theory about the inability of protons to decay, and it led me to a point where I read something about some special kind of star called an "iron star". Can anybody enlighten me a bit, if possible, on what exactly it is and why it may be significant? And how do iron stars form?
Comment: Did you check [Wikipedia](http://en.wikipedia.org/wiki/Iron_star)?
Comment: I'm torn on making this an answer cause it's based on bunk and the dismissal of fusion theory and this is an old question, but it's more likely the reference to Iron stars is based on junk science.  See here:  http://curious.astro.cornell.edu/about-us/53-our-solar-system/the-sun/composition/158-does-the-sun-have-an-iron-surface-intermediate and http://www.spacedaily.com/news/iron-02b.html  Bunk science shouldn't get too much attention but it can still be used as a teaching tool in the sense of "how do they know".   There's the hydrogen spectrum line for starters.
Answer: "Iron stars" are a hypothetical kind of stellar remnant - similar to a neutron star or white dwarf - that are hypothesized to form in the far future of a Universe undergoing heat death, under the assumption that protons do not decay, which is something that we do not know if is or is not the case. Some of the more promising theoretical models for proton decay (a fair number of so-called "Grand Unified Theories" [GUTs] which one should note, despite confusion in the popular press, are not the same thing as unified quantum gravity theories like string theory) have already been experimentally rejected, but that doesn't mean it doesn't occur at a rate slower than we can currently detect (or may ever be able to).
In particular, the idea rests on the fact that, given infinite time, there is no such thing as a stable element except, perhaps, for iron. What we call "stable" elements are really just radioactive elements with a half-life too long to observe, or too long to matter, whichever you prefer. For example, up into maybe about 16 years (300 megaseconds) or so ago, the element bismuth (element 83) was widely believed to be entirely stable, but then its most stable isotope was discovered to be unstable to alpha decay with a half-life of around $10^{19}\ \mathrm{yr}$ ($10^{20}\ \mathrm{Ms}$).
Feynman (I believe) once said that "everything not forbidden is compulsory". What this means is that, according to the laws of quantum mechanics, there is a nonzero probability that an agent can register any process not forbidden by, say, a conservation law, as having occurred, and will register such as having occurred given infinite time. In the case of atomic nuclei, if there is a nucleus with less nuclear energy than a given one, there is a probability to register the latter as now being the former, i.e. as having undergone a decay to it. (It cannot go the other way, because that would imply a violation of the law of conservation of energy.)
All elements heavier than iron have more nuclear energy than iron. Thus, by this principle, ALL isotopes of them are radioactive: we just don't know the half-lives. E.g. even common copper is radioactive (unstable) and will likely undergo alpha decay to iron, two atomic numbers below it. It's just that the timescale for this decay is likely so inordinately long that we cannot ever have any hope of observing it directly.
Thus, given unlimited time, anything made entirely of such elements heavier than iron will decay until it becomes purely composed of iron.
However, now one might be wondering something: clearly, stars are not made of heavier elements, and white dwarfs are typically also made of light elements like carbon and oxygen, and iron cores collapse into neutron stars if not black holes, neither of which can reasonably be called "iron", so how can we have "iron stars"? Well, it turns out that something opposite to radioactive decay will also happen for at least aggregate concentrations of light elements too: they will undergo cold fusion. Helium has less nuclear energy than 4 (protonic) hydrogens - that's why the Sun and main-sequence stars are able to perform hot fusion to a net energy gain to begin with. Contrary to what you may have heard, cold fusion is not impossible: it's just really damned slow, as in, taking far, far longer than the elapsed age of the Universe, just like it is for the decays just mentioned. But in any case, in "eternity", cold fusion will likewise raise the atomic number of the nuclei in a white dwarf, to again, converge on iron. This is an "iron star".
But, as said, this all depends on two things:

that the ultimate fate of the Universe is heat death,
that there is no proton decay.

Neither of these are things we can "know" to good confidence. In particular, there are still major open questions in fundamental physics that leave the door wide open to these being things that could go differently. In the case of the ultimate fate of the Universe, it is intimately bound up with the nature and governing laws controlling the still as-yet poorly understood "dark energy". Heat death will occur if the dark energy remains constant, i.e. acts as a true cosmological constant as per Einstein. However, if the dark energy either rises or falls with time, we may end up with two other "catastrophic" scenarios respectively called the Big Rip and Big Crunch. We have no evidence to rule these out because we don't have any regarding the physics governing future evolution of dark energy. The formation of iron stars by cold fusion and radioactive decay of so-called "stable" heavy elements is estimated to take a half-life of $10^{1500}$ (years, megaseconds, pretty much doesn't matter at this scale as that exponent itself is likely approximate).
Likewise, there are potential mechanisms - such as quantum tunneling via "virtual black holes" - that could still cause the decay of protons with half-lives on the order of $10^{200}$. A detector of the type we use now to look for proton decay (basically a big tank of water) could not detect these directly, as it would require many orders of magnitude more mass than there is in the current observable Universe and, moreover, would collapse into a black hole long before one got that far.
Answer: The basic premise of an iron star is a 'dead' star whose mass is made primarily of iron.  It's a hypothetical type of compact star.  Wikipedia has a bit of a blurg here: https://en.wikipedia.org/wiki/Iron_star
The process of forming an iron star would be tricky, because normally iron does not fuse and so the star would normally collapse under it's own weight - this is why the Wiki article describes a cold-fusion process via quantum tunneling processes.
This article describes the process of fusion in stars and might help you understand why this is more significant compared to regular stars: http://www.eso.org/public/usa/news/eso0129/
Comment: This makes little sense. Iron stars are not undergoing fusion, they would be supported by electron degeneracy pressure. I also doubt that iron is the lowest energy density nucleus. It would more likely be Nickel 62, or possibly something slightly more neutron rich, depending on the mass of the compact object.
Comment: Sounds like the liquid water zone would be located *quite* close to an iron star, if such a thing were even to exist.
Comment: But how would they be called a "star"?
Comment: @Rohit Nutalapati - it's a "dead" star, or more properly, a stellar remnant.

What are iron stars?


Do Full Nodes perform Proof of Work to validate a Block?

Question: I do understand that Full Nodes validate all transactions twice based upon the public key of the users. Firstly, once a transaction is unconfirmed and secondly the transactions that have been mined in a block. My Question is do the Full Nodes also perform Proof of Work to confirm the validity of a Block or not?
Answer: Hashcash-style proof of work is a simple search process: Try lots of nonce values until you get an acceptable solution.  To verify a node simply just has to try one value, the one the miner provided.  So it uses the same test but does not search, as a result it does very little work.
The Bitcoin software hasn't really validated transactions twice since 2012. Caching is used to reuse the validation effort from the first time the transaction was seen, especially for the digital signature verification.
Very careful engineering has been required to make sure that the handling of unconfirmed transactions can't accidentally cause invalid blocks to pass. This is especially a concern because complications like locktimes and soft-forks can make the validity of a transaction some what conditional. But in the latest software really the only validation needed at block time of an already seen transaction is the locktimes and double spending checks.
Answer: No, there is no need for a node to perform PoW, since the PoW has already been performed.  All they do is validate that the block/nonce pair equals a valid hash for the specified difficulty.  It's just a single operation per block.
Of course there is other validation, such as deciding which block is correct in cases where there are two competing blocks, but that's not PoW.


Is there a way to keep sudoers from editing stuff in /etc/ssh/sshd_config?

Question: I have root login disabled in SSH and I want to be able to eliminate the possibility of a sudo user editing the /etc/ssh/sshd_config file and enabling root ssh login. Is this possible?
Comment: Unsure, but potentially you could use LSM (grsecurity/AppArmor/SELinux etc) to finegrain what sudo can do. Then it should be possible to limit the "unlimited power to file permissoins" for root.
Answer: Ultimately, blacklists don't work: it would be a vain endeavour to try to find all ways by which a root-equivalent user could alter the contents of /etc/ssh/sshd_config and try to fix them all. For instance, a lot of commands can output some data in a file whose name is provided as parameter -- that could be used to alter /etc/ssh/sshd_config.
Instead, use whitelists: explicitly allow sudoers to run an explicit, small sets of commands (e.g. a command to trigger a reboot, if that is relevant to your situation), and all others must be forbidden.
Alternatively, use SELinux to constrain sudoers into a not-exactly-root role and get /etc/ssh/sshd_config out of their reach. But this may involve some considerable configuration work (SELinux seems to be up to the task, but I have not tried it, so I do not guarantee success here). Also, be aware that the power of nuisance of a rogue root user tends to be pervasive: there are many many ways by which such a user can harm your security. It seems better to just not trust evil people with sudo powers. Or maybe some more comprehensive isolation layer would be warranted: instead of having several users in a single machine, with some semi-administrative powers, give a virtual machine to each user, that he may play with at will without impacting the other users. Depending on your context, this may or may not be applicable.
Comment: `yum install` manages the system packages -- including openssh and its configuration files, like `/etc/ssh/sshd_config`. If `yum` can do its job under whatever constraints you want to apply, then it can do _anything_, up to and including replacing the kernel. I fear that your problem does not have a solution as stated.
Comment: I like what your saying but its not about trusting evil people. It's about minimizing risk in the event that an account gets compromised (eg. someone looks over my shoulder with a set of binoculars and sees me enter my password)
Comment: I basically want to be able to do everything I need: yum install, vim, configure, make, etc. I was hoping there is a way to just make a new user group like sudoers and have it not be able to edit /etc/ssh/*
Answer: The closest you are going to get to making that impossible is to use an extremely restricted set of what is possible through sudo.  You will have to forbid access to vi, editors, shells and su.  You're better off trying to determine what commands are necessary and hoping none of them have the ability to edit files or directories or execute commands.
Ultimately if you are giving someone privileges on your system, you are inviting risk.
There are some other alternatives you can consider:
Monitor the SSH logs for root logins with password auth.  That's your leading indicator that your file has been changed.
Monitor that file for changes with a frequently running cron.  If someone modifies that file and doesn't notice the monitor, you'll catch it.
Comment: If available, an `auditd` *watch* is likely better than polling or monitoring after the fact. If the OS and filesystem support it, making `sshd_config` immutable (e.g. via `chattr`), or mounting `/` read-only are possible alternatives. A last resort to permit selective sudo editing of files might be a chroot wrapper script, and a statically linked editor... yuck.
Comment: `cat` may be safe or not, depending on whether there are files that must remain confidential, such as a full-suoder's private ssh key. But `tee` is definitely unsafe.
Comment: Agree with Gilles.  I'll take cat off of my list.  We're all cat people, right?
Answer: Yes, with AppArmor it might be possible:
I have tried arround somewhat with using MAC (mandatory access control) and the AppArmor LSM (linux security module) and I found, that you might have a change using AppArmor to make /etc/ssh/sshd_config impossible to be written to using sudo.
This AppArmor profile would limit what the user can do after having gained "root power" via sudo

/usr/bin/sudo {
  capability setgid,
  capability setuid,
  / rw,
  /** rwmix,
  deny /etc/ssh/sshd_config w,
  deny /usr/sbin/aa* rw,
  deny /sbin/app* rw,
  deny /usr/bin/sudo rw,
  deny /etc/apparmor.d/profile.usr.bin.sudo rw,
  deny /sys/kernel/security/apparmor/ rw,
  deny /sys/kernel/security/apparmor/** rw,
}

To be safe, first lookup if there is already an preexisting AppArmor profile for /usr/bin/sudo

$ aa-status | grep sudo

In case there is none the output is empty! If not empty you should best talk to those guys who have setup the profile and not go on here.
If - as expected - there is not yet a profil you ca create one with this command:

root@computer:/root/# echo "/usr/bin/sudo {
>   capability setgid,
>   capability setuid,
>   / rw,
>   /** rwmix,
>   deny /etc/ssh/sshd_config w,
>   deny /usr/sbin/aa* rw,
>   deny /sbin/app* rw,
>   deny /usr/bin/sudo rw,
>   deny /etc/apparmor.d/profile.usr.bin.sudo rw,
>   deny /sys/kernel/security/apparmor/ rw,
>   deny /sys/kernel/security/apparmor/** rw,
> } " > /etc/apparmor.d/yourprofile.usr.bin.sudo

Then you can start/setup the new profile

root@computer:/root/# apparmor_parser -r /etc/apparmor.d/yourprofile.usr.bin.sudo
root@computer:/root/# aa-enable /etc/apparmor.d/yourprofile.usr.bin.sudo

resultingly a for a user this should be the result:

ssh_user@computer:~$ sudo bash -c "echo 'PermitRootLogin yes' >> /etc/ssh/sshd_config"
[sudo] password for ssh_user:
bash: /etc/ssh/sshd_config: Permission denied
ssh_user@computer:~$ sudo -i
root@computer:/root/$ echo 'PermitRootLogin yes' >> /etc/ssh/sshd_config
-bash: /etc/ssh/sshd_config: Permission denied
root@computer:/root/$ aa-disable profile.usr.bin.sudo
Can't open perl script "/usr/sbin/aa-disable": Permission denied

Sadly I cannot give you insight how to implement this in other
LSM like SELinux or grsecurity.
Anyways I would appreciate to get a feedback if the solution helped you :)
Be aware that the limitations regarding what can be done with sudo are for everybody and that means if you use sudo to get superuserpower you will suffer the same limitations (i.e. you cannot disable apparmor, nor /etc/ssh/sshd_config yourself. Only one who can is a real root via login.
Comment: Both LSMs in general and AppArmor in particular are fine. The issue is with that particular profile. Allowing root to do everything except a few things is almost always a bad idea. Two ways of bypassing it immediately came to mind: 1. Add a job to /etc/crontab that overwrites sshd_config. 2. Run passwd to set a password for root that you know, then exit sudo, su to root, and change sshd_config.
Comment: Downvote for being trivially bypassable.
Comment: @JosephSible Do you suggest that [LSM](https://lwn.net/Articles/748868/) are not effective in general, or apparmor in particular? if you can (trivally) sketch how the bypass would be done, would allow to improve the answer, thanks in advance :)
Answer: You could write your /etc/ssh/sshd_config to a physically read only drive.  In that case even if you were logged in as root itself, you could not change sshd_config.
But then you would have to watch out for

if the user can mount and unmount drives, then they could just unmount whatever drive you have sshd_config on
if the user has physical access to your machine, then they could just replace the disk
Answer: I like Scottie's answer of chattr +i /etc/ssh/*
Perhaps then you then could use visudo -f /etc/sudoers to change to:
%sudo   ALL=(ALL:ALL) !/usr/bin/chattr, !/bin/su

This method should blacklist sudoers from running chattr and using sudo su but the easier method would just be to whitelist commands sudoers are allowed to run. All of this is one extra layer, but just like anyone with sudoer access, they can undo anything that root can.
Comment: `sudo -i`, run python as root and do a `import sys`... If you have limited sudo capabilities it's often *extremely* trivial to escalate this to total root access.
Answer: If it were me, I would just set the /etc/ssh files to immutable:
chattr +i /etc/ssh/*

Are you truly worried abut the file itself changing, or could you live with just knowing that the file has been changed?
If the latter, there are various intrusion detection programs (e.g. aide) that will monitor these files and alert you if it changes.
There are also configuration management programs, such as puppet or chef that can be configured to replace the files with a known good image if it were to change.
Comment: This can be undone with just a chattr -i.
Comment: Only if the us is smart enough to figure that out.  Not everyone is.
Anything that a smart SA can do can be undone by a smart hacker. It's really just trying to make sure it doesn't get changed accidentally by a user.
Comment: No, good security measures can't just be undone by any smart hacker. Only bad security measures can.
Comment: Disagree.  It's like locking your car. That only keeps the honest people out. If a crook really wants your car, he'll take. Good security measures reduce the *risk*, they do not stop someone who really wants to mess with your system.
Comment: No, this is even less security than locking your car. Root can do chattr -i with no special security requirement, and only root can edit /etc/ssh/* anyway, so you've literally added no security boundary at all.
Comment: ONLY if the user is smart enough to know that. I have interviewed many SAs who don't know this. Besides, YOU'VE MISSED the point that I was making.


Can the recipient of my emails know my IP address?

Question: When I send out emails using Gmail, is my IP address being recorded? Can the recipient of my Gmail message know my IP address and thus infer where I am located?
Comment: See also http://webapps.stackexchange.com/questions/6942/when-does-gmail-include-the-x-originating-ip-header
Answer: Send yourself an email (at a non-gmail email address) via gmail and read the "full header" or "message source", especially "X-Originating-IP".
Compare this with your own external IP address (google [my ip is]).
The header of an email which I sent from my own gmail address to my own gmail address ("Show Original") did not contain an originating IP address, or any IP address except a reserved address in the 10.x.x.x range (in other words no IP address that would be identifiable as mine).
Then, I sent an email from my gmail address to myself at another email provider. The header of this email had an X-Originating-IP address which resolves to Google, Inc. It contained several IP addresses, none of which were identifiable as mine.
In appropriate cases a subpoena, search warrant or other lawful process directed to Google, Inc. would, of course, unmask your IP address and reveal your general location (and more legal process would force your ISP to reveal the IP address subscriber's name and address).
Your IP address was recorded by Google when you sent the email, and by God knows what other spooks inhabit the interwebs between you and your ISP, and between your ISP and Google, but it was not sent to your mail recipient(s).
Comment: Readers beware that this answer is specific to GMail. Other mail providers might behave differently, especially when you use a real mail client and not a web interface.
Comment: More generally, this answer assumes neither the sender nor the recipient are running their own mail server.
Comment: Note also that Gmail uses TLS for connection to the web browser.  Those "other spooks" may be hoovering up the encrypted data streams, and the NSA might even be able to crack them, given enough interest, but the connection to Gmail is prob ably safe from others.
Answer: If you use Gmail in as webmail (by sending emails on gmail.com), your IP address and hostname will not be leaked.
But if you use Outlook or Thunderbird like mail client to send gmail by using SMTP, then your IP address and hostname will be travel with your email.
Comment: If someone wants to be a nasty hacker, they could sign up to lots of email lists and build an IP <-> name,email database.  I'd be surprised if actual hackers are not already doing this.
Answer: Google/Gmail strips the originating IP address (among other things) from outgoing messages - so the receiver cannot see the IP to indicate where you are, or more correctly, where the email originated from.
***update - seems if the email is sent between gmail accounts the originators IP is in there...
Other online email services (Yahoo...) leave the originating IP in the header. You could use a VPN to obfuscate the IP.
For privacy this IP stripping is great, for doing illegal stuff, then don't use email.
Comment: or if you have any concerns about privacy, such as not wanting other people to do illegal stuff to you, then don't use email.  :(
Answer: 2014, June 26: I used the Gmail web interface to open an email sent from a Gmail account to a Gmail account, clicked next to the "Reply" icon, and selected "Show original" and I was able to see the originating IP. In this case it was the IP address assigned from my ISP to my router at home (which I needed because it changed and I wasn't using any dynamic DNS tool)
Answer: Select the message you want to view, click on "More" (beside the reply button) and select "Show original". It will open a new window with the email header information. Under the "Received" section will be your IP address and all the corresponding mail transfer agent (MTA) information that the email traveled through.
So the recipient may roughly guess your geographical location via your IP address information provided you are not using either VPN or webmail. If the sender had used Google webmail, then the IP address will point to the Google's mail service rather than your IP address. A further check with Google or your VPN service provider is needed to determine the IP address from their log files. Finally, with the IP address, cross referencing from your ISP's DHCP records can determine exactly who sent the email.


Contacting a potential research adviser

Question: I wanted to know what the best next step is given my situation.  I have been interested in doing research with a professor, however after the initial response from him about setting up a time to meet he has not responded.  Given it was summer I assumed he was busy with travel and grant proposals.  Upon sending two more emails he did not respond about setting up a specific time.  As such, I went to his office.  He send he would send an email setting up a time.  How long should I wait to hear back with a response?  I understand professors are very busy, however there is a deadline to enroll in research credit.  I am hesitant in sending a "reminder" as I don't wish to annoy him.
Answer: If you think you are on the edge of being annoying, then it might be better to wait. But, you don't have to wait passively. See what other, backup options you might have with other professors and start a conversation there. Be a bit tentative with them, of course.
And, if he is negligent about responding, note that he might also be negligent about giving you the guidance you need. So, other options are worth a look.
But, it is also possible that he is just a last-minute procrastinator sort of person, so be prepared to spring into action if you get a favorable response.
Comment: Thank you for the information.  If for some reason he does not get back to me within a few days should I send another email?  I'm quite keen on working with this person and given he has acknowledged I would like to think I have a shoot.
Answer: I'd move on and find a different professor. The person you describe doesn't appear to have the minimal communication qualities necessary to be a good mentor.

Contacting a potential research adviser


Issue in Synchronising Contacts

Question: I have two contacts :
In Audience Manager DB, its showing 2069(test1 user) and 2070(test2 user) ids for these two contacts while in Subscription DB its showing 2070(test1 user) and 2071(test2 user) for the same contacts.
When I am trying to change the profile of test2 user(2070 of AM DB) from website, its showing me information of test1 user(2069 of AM DB) which is wrong.
How can I resolve the same, Sync service is already running.
Answer: Keep in mind that the database IDs will not match across the two databases.
That is perfectly normal.
What matters is the identification key(s) that you provide. They should be the same on both sides. If your problem is that they are not, you have a serious problem that we are unlikely to be able to solve through this site; you'll need to contact customer support.
If the problem is just with misunderstanding the identification of Contacts?
Well, hopefully you are now the wiser :)
Comment: Contact_ID field in CONTACTS_EXTENDED_DETAILS is having different values in both the DBs.
Comment: As mentioned, that is perfectly normal. How are you loading the Contacts? If you used the sample pages as a starting point, you should be loading the contacts using the identification keys - which will match on both sides.
Comment: I need to pick the contact using TCMID of the contact in one of the scenario so I am using something like Contact.GetFromContactIdentificatonKeys(new string[] { Context.User.Identity.Name }) and  Contact.GetFromInternalContactId(TCMURI); in second case I am getting the wrong user because of Contact_ID differences in DBs
Comment: Indeed that will not work. You should use the identification keys to read the correct Contact. You cannot expect the same URI on CD and CM - that's not going to happen.
Comment: Thanks Peter, I am not using Contact URI now.
Answer: I don't have a running AM setup to check right now, but I think that the IDs in the subscription management database do not necessarily match those in the CM side database.
The reason for this is that contacts can be created both on back and front ends so trying to have a unique single column index for both would be impractical, especially as you could have multiple front-end databases.
You need to identify which columns identify a contact uniquely as defined in the documentation [login required]. The sync process probably uses those to sync, rather than IDs.
Comment: Contact_ID field in CONTACTS_EXTENDED_DETAILS is having different values in both the DBs.

Issue in Synchronising Contacts


Tag synonym suggestion [action replay] -> [cheats]

Question: I think making action-replay into a synonym of cheats makes sense since AR is a kind of cheaty thing.
Answer: There are only two questions tagged action-replay, and those questions are also tagged cheats. Seeing as we don't have tags for gameshark, game-genie or any other cheat device that I am aware of, can we not just remove the action-replay tag from those two questions (as it states in the questions specifically that they are looking for AR codes), making the point of the synonym moot?
Comment: With no response to the contrary in 5 days, I've gone ahead and done this (and also improved the questions).
Answer: I think we should just kill cheats and be done with it.  It's not a very good tag.
Answer: In these situations we should always opt for more specific tags, rather than tags so generic they're actually useless; so-called "meta tags" such as cheats, which as OrigamiRobot points out isn't exactly our best tag ever. action-replay, otoh, is a fine tag.
Comment: I think [tag:action-replay] is just as bad as [tag:cheats]


What is the block / confirmation time for NXT coin?

Question: what is the block time to get my transaction confirmation? Do i still have to wait 10+ minutes to make sure a double spend didnt happen?
Answer: Transactions are being included into blocks in 1 minute in average. Longer you wait - higher a chance that a double-spending won't happen. There is no such a number that guarantees 100% irreversibility.
1 confirmation is not secure at all. 10 confirmations is recommended for small amounts, 720 confirmations - for big ones.
Comment: i just sent 8 nxt to one of my wallets and its been 5-10 minutes and i still didn't get any confirmations yet. but it does show up that its sent in the other wallet.
Comment: 1 minute is AVERAGE time, real time varies from seconds to an hour. Also it can be a local node issue related to incorrect time/timezone, bad connection or a client software bug.


8 speed drivetrain stronger than 9 speed?

Question: I see a lot of people recommending 8 speed drivetrain over 9 speed for a touring bike because they are supposed to be stronger (e.g. in the buyers guide of the Adventure cyclist magazine, issue april 2011, page 16) . Is that still true or did technology catch up?
Comment: 2011 is 6 years old, technology has definitely moved on and can make stronger/better chanins.  This tech came trickling down from having to make stronger/better and thinner chains for 10 and 11 speed.   Also, the use of master links rather than pushing out/in random pins increases the overall strength by raising the basement level.
Comment: It would improve the question if you included a few links to show where and in what context such recommendations were made.
Comment: @Craggie - My answer would have been much the same 6 years ago, 9 speed came out in 1996, so 9 speed was over 15 years old then.... If the OP was asking about 11 vs 12 Speed, we might have something worth exploring.
Answer: My guess is in reality no statistically measurable difference between 8,9 and even 10 speed setups. 8 Speed these days is low cost components, meaning you are fitting out a bike with low cost gear. Even 9 speed is lowish cost. 10 is geting into quite fine tolerances but has been around long enough to be well understood. 11 and 12 speed setups might be a concern, but I would not fit them because of concern over strength.
More important though is "Strong enough" - once the gear is "strong enough", does it matter if one is stronger than the other. And setup built with components of good enough quality to be used where reliability is a concern is strong enough.
The disadvantages of more gears is finer tolerances meaning wear is a bigger issue. Wear is a different concern to strength as it affects everything but is predictable, and easily managed with normal maintenance. (Cost is another discussion)
There might be reasons for not going to higher gears - availability of components in remote places in the event of a break down. However going 9 speed over 8 speed has little disadvantage here. Most components are interchangeable between these, and if needed you would as easily get you bike up and running on the off the shelf components at the most basic bike shop  with 9 speed as 8 speed.
As eluded to earlier, cost might be a reason to stay on 8 speed - but that is a different question (and I have my doubts it is significant).


Disable Link to Post from Showing Up in Post's Comments?

Question: When I link to a another post in one of mine, is there a way for it not to show up in that entry's comments? Very small, new blog at the moment... I honestly just don't want all the exposure from being in a big blog's comments
Answer: It sounds like you're talking about a pingback. You can disable it from Admin|Settings|Discussion. Uncheck Attempt to notify any blogs linked to from the article.
Or, you can do it on a post-by-post basis under "Discussion" below the post you're creating/editing. You might need to enable "Discussion" in the "Screen Options" menu at the top of the page.


Automation tool with record & playback option

Question: As I know we have selenium IDE tool to record and playback our automation script..while recording in ide some Ajax function and date pickers are not working properly..I want to know is there is any other tool like IDE to record & play back my scripts..
Comment: There is actually plugins for the IDE that will do an implicit wait and then just do a check for text on the page that would be indicative that the ajax call has completed. I would recommend just not using record and playback though.
Comment: This is far too broad to be answered. In general, software recommendation is frowned upon unless it can be properly (narrowly) scoped. Thanks!
Answer: There are many. UFT within HP ALM is one such application. You should be able to google them, and find something that will meet your needs.
Comment: This answer is better off as a comment on the question.
Answer: GhostInspector is another tool I use for UI testing. https://ghostinspector.com/
However I find that all tools and framework struggle with ajax and explicit/implicit waits.
Comment: Do explain why you prefer the tool for which you have given a link.
Answer: I personally used HP UFT and Ranorex and tried TestStudio from Telerik and TestComplete from SmartBear. If you're doing black box testing the only realistic way I found to check if an Ajax event is completed is doing what the user will do: to check for visual cue, most of the time a new object created or removed from the page.
Some of those tools have trouble tracking automatically the objects, if that's the case using XPath can help, XPath is supported by all the software I tried.
I also know a few people that use image recognition as the last resort to track an object, I don't know if that's possible with Selenium.
Answer: I think you could give Ranorex a try. Automated test cases can easily be set up with the capture and replay functionality, as you can read here: http://www.ranorex.com/how-test-automation-works.html. Additionally, it is now possible to execute tests remotely with Ranorex Remote.
Answer: I would recommend SeeTestAutomation: It enables you to record scripts, as well as play them back. You can use it free for 30 days and see if it meets your needs.
Comment: :-) Everything I said on the other post applies here too. Only issue here is that the *question* is a poor one, which means answering it is even harder!!


Export from OneNote 2007 to Word and retain outline styles

Question: OneNote 2007 has the ability to export to Microsoft Word (File | Send To | Microsoft Office Word); however, I'm looking for a way to export to Microsoft Word and retain the outline levels so that it can be easily formatted with Word styles rather than having to manually set the outline levels in Word Outline mode after exporting.
Answer: There's no simple way of doing this. OneNote converts the idented OneNote outline into Word paragraph idents. You'd have to do some clever search and replace looking for particular idents (find, format, paragraph, indentation) with heading 3 style (format, paragraph, heading 3).


Time needed to full self-discharge of speedlight capacitor

Question: I need to repair the Nikon's SB-600 speedlight. As I need to access to only the bottom part of the speedlight I skipped the danger of electric shock. However when I tried to disconnect one of the socket I get the shock to my finger. As I have no resistor I put the speedlight in the closet for about 24 hours and now I'm wondering: how likely that the capacitor is discharged to safe level?
Comment: Chances are that after 24 hours the cap has discharged most of the way.  These things are small anyway, so even a full charge may be unpleasant, but unlikely to hurt you.  I'd be careful to make sure you don't have a discharge path *between* your hands as that current will flow near your heart.  Anything that a small speedlight can do that stays within one arms is very unlikely to cause anything more than a unpleasant jolt.  However, resistors are cheap and plentiful.  Get a 10 kOhm resistor already and discharge the thing properly if you're that worried about it.
Comment: @connersz the capacitor of the flash doesn't work like that. The items on the screen and the lights are powered by the batteries. The batteries also charge the capacitor, but the capacitor holds charge on it's own, and releases all of that charge to the bulb, but only the bulb, in one go.
Comment: I don't know if this will help, but have you ever had an electronic device where an LED or something stays on when you unplug it? Well more often than not if you then press the power button it will suddenly lose all that power and the light will go off. I have a similar thing with my breadmaker, the screen stays on when I unplug it for about 10seconds but if I press a button before that time, it will go off, like the power has been released. So what I am suggesting is try pressing the buttons to discharge any remaining power.
Comment: Note that one thing you could do is use some part drained batteries in it that mean the recycle time is much reduced. Then fire a test flash and open the battery compartment immediately after. The less time between firing the flash and disconnecting the batteries, and the longer the recycle time from the batteries, the less chance the capacitor is going to have to recharge
Answer: A properly formated electrolytic capacitor almost has sort of an imprinted charge (like electret condenser microphones) and will lose very little charge by itself since the voltage is what actually causes it to maintain its isolation (which is why you should power up flashes for at least 15 minutes every 3 months or so if you don't use them or the isolation will deteriorate, greatly increasing the danger of breakthrough when finally powering up the flash, and breakthroughs are often terminal).  It very much depends on the rest of the circuitry how much charge will stick around if this is a flash in active use (some flashes will discharge controlledly in few minutes, others won't).
Note that using an 1/1 manual flash is not guaranteed to get rid of all charge: flashes cannot utilize every bit of charge and may maintain reserves for preflashes, red-eye flashes, prefocus flashes and what other uses are there.
So in general be very very careful until you actively discharged the capacitor, and don't underestimate the stored energy when doing so as it can act rather destructively.  If you have the schematics, there often are terminals reasonably safe for discharging since they have circuitry limiting the surge and dissipating the energy.  If you cannot read schematics, are you sure you are the right person opening a flash?  Some wand flashes store 90J or similar.  A 100th of that energy will give quite a jolt to horses touching a medium-size electric fence.
Answer: Surprisingly, but after three days the voltage on the board connector was still more than 200 Volts! So I have to state that the capacitor have very low self discharge current.
I connected the resistor directly to the board connector as I could not reach the dedicated contacts on the flash head.
Answer: If the flash is set at 1/1 full power, then it's less than on second after you have pressed the test or shutter button.
Unless you are an engineer or good flash tech, then you use a resistor and short the capacitor to ground.
Answer: I have personally pitted screwdrivers on (non-photoflash) electrolytic capacitors that had sat charged but idle for WEEKS.
Self discharge specifications of such capacitors will always be worst-acceptable numbers, since self discharge and leakage currents are usually considered undesirable to an engineer.
Never rely on a big capacitor being safe unless you either a) received it obviously shorted, b) discharged it thoroughly, c) measured the voltage across its terminals.


What is a good website or book to learn kitchen techniques?

Question: For example different cutting techniques such as julienne or brunoise. I'm aware it can never be the same as attending a proper cooking course but still with a good book with pictures or even better online videos you can learn something. Basically I'm looking for a place to get a crash-course in what you'd learn in a proper cooking college.
Comment: See also this question, which asks: "What is a substitute for going to culinary school? Is there?" http://cooking.stackexchange.com/questions/7438/what-is-a-substitute-for-going-to-culinary-school-is-there. I would consider this close enough to be a duplicate.
Comment: The answer is obvious: This one!
Answer: Jacques Pépin's Complete Techniques is an extremely useful guide to every technique you can imagine. Each step of each technique is fully illustrated with photographs.
Comment: It looks really good. I'll get it as soon as possible ;-)
Comment: I got the book and its great! Thanks for the tip.
Answer: http://rouxbe.com/ provides videos and demonstrations of cooking techniques. (despite my previous username I am not affiliated)
Comment: I signed up for the trial and it really is a nice site. Very good explanation of knife sharpening with a waterstone.
Answer: I have never been to a proper cooking college but I have taken a few cooking classes at PCC and Whole Foods, so I could not offer my opinion on how it compares, but this website http://jamieshomecookingskills.com/index.php is a great resource for learning a lot of different basic skills and it has everything from recipes to videos and a lot of techniques in between.
Answer: I would recommend www.seriouseats.com, especially J. Kenji Lopez's knife skills videos. Also Lifehacker.com has done a few articles on beginner kithen stuff, like how to make a scrambled eggs and how to dice an onion.
Also you can pick up Alton Brown's first cookbook.  He does a good job of grounding his recipes in the science involved.  Also, the complete good eats series has a lot of great stuff in it.
Answer: Gordon Ramsay Cookery Course on youtube. Fast but good (and free!) content from a great chef. I've learned different ways to cook chicken and turkey. Flavors are excellent and really straightforward type of cooking. I.E nothing frilly.


Will the SuperDraco powered Dragon be able to "jump" on the Moon or Mars?

Question:
Does the Dragon reusability concept of SpaceX include the ability to reactivate the engines after landing to make a "jump" to a new soft landing location some kilometers or so away on the surface?
Is it (will it be) capable of hoovering at low altitude over the landscape for tens of minutes to for example get feedback from human control on Earth to Mars?
Or is the Dragon concept designed just to make one soft landing, not able to take off and land again without refurbishing?
Comment: Tip: The "Tens of" terminology popularized by Carl Sagan is so imprecise it should always be avoided. "Tens of minutes" is anywhere from 20 minutes to infinity.
Comment: Except that everyone knows that when someone says "tens of minutes" they don't mean more than two hours.
Answer: Yes, the SuperDraco thrusters are restartable. The propellants used are MMH (Monomethyl Hydrazine) as fuel and Dinitrogen Tetroxide as oxidizer which are hypergolic, meaning they ignite on contact with each other and that greatly simplifies engine's ability to restart, throttle and achieve full thrust in quoted 100 ms.
Ability to hop from one landing site to another and hover will of course depend on amount of propellants available for such maneuvers relative to vehicle's payload mass, gravity and atmospheric density, i.e. achievable engine efficiency given specific conditions and thrust to weight ratio for a specific mission.
Since they'll be used on DragonRider, the crewed version of the Dragon spacecraft, their target performance will have to match requirements for LES/LAS (Launch Escape System / Launch Abort System) for human-rated vehicles, and SpaceX has plans to soft-land them on Earth as a part of their fully re-usable launch vehicle (Falcon 9 and later Falcon Heavy) once returning from LEO orbital speed to a soft landing in Earth's gravity, so I would imagine hovering and hopping could also be achievable on the Moon or Mars in reduced gravity w.r.t. Earth's surface.
One note though, that there would be little point in waiting for Earth based control station's communications to Mars during critical maneuvers like this. Depending on Mars' position relative to the Earth (closest at ~ 54.6 million kilometers), one-way communications delay is at minimum roughly 3 minutes. Mars landing craft will require far greater autonomy than having to hover over some surface to wait for input from Earth.
Comment: And if you're really unlucky and picked a bad day to launch, the Sun will be in the way of any transmissions.
Comment: @MichaelKjörling If you don't relay it, then yes. And the comms delay would be on average far greater, and that's of course one-way direct line-of-sight delay. If you're targeting ideal launch opportunity for a Hohmann transfer, when you're there ~ 7 months after you launched from Earth, Mars would be farther from Earth, and any relays used would also increase total distance and comms delay.


bitcoin volatility and transaction fees

Question: We know that the Bitcoin currency is volatile, but does the transaction fees correlate with it's volatility? Is it right to assert that if there is high level of Bitcoin demand, then the currency goes up, and then if the demand comes from a great amount of person, then the network size increases and so the transaction fees could be balanced by a greater availability of blockchain space, or am I going wrong ?
Answer: The logic behind the transaction fee in the bitcoin network is that the miners take  in consideration first the txs that have higher fees to be added to the blocks, those txs are taken from the mempool, the place where they should wait until miners decide to add them to a block to be validated.
For example:
If I perform a transaction that has a fee of 300 satoshis it will be first added in the mempool before it goes to a block; and let say, that some minutes later you perform a txs that has a fee of 30000 satoshis it will added  to mempool too, but the miners will consider first your tx because of its higher fee.
Taking that in consideration, when the bitcoin price get up, usually there are a lot of people performing txs and since the size of the blocks is only 1MB, where only can be attached about 2500 txs, much of those people prefer to pay higher fees so their txs could be added to the next block. That cause the mempool get full of transactions waiting to be added to a block.
According that explanation we can say the transaction fees is not directly correlated with the  volatility of bitcoin, it is more correlated with increase or decrease of quantity of transactions waiting in the mempool and the wish of people to get txs done asap. If there are many txs in the mempool people will be more tempted to pay more to get them done.
Answer: No, the more people use Bitcoin, the more the transaction fees will go up. This is caused by the fact that the blocks are generated with a 10 minutes average and they can only hold up to 1mb of data. The more people use Bitcoin, the more there's a demand to have their transaction in that small 1mb block. This is why there was a fork for Bitcoin Cash which advocates bigger blocks (Currently 8mb, but they will scale with the demand to keep fees low).

bitcoin volatility and transaction fees


Android on Copay still available?

Question: Hi I was downloading Copay and it said ;

WARNING: Chrome App will not longer be supported
Google has announced that it will be ending support for Chrome Apps on non-Chrome OS platforms in 2018. This means that our Copay bitcoin wallet will no longer be available. Please use other Copay platform. If you are using a hardware wallet, we recommend that you move your funds to other wallet as soon as possible.

I was wondering if it is okay to download from google store and use or if I should just use the wallet on another platform?
Answer: Android apps are unaffected by this change.

Android on Copay still available?


What is the threshold between deciding to send an email or schedule a meeting?

Question: I would like to ask a colleague for some advice on a project, but I am unsure as to whether an email would suffice or if I should schedule a meeting. What things should I consider when making this decision?
Answer: Send the email and see what he says first. If the reply is suitably complex you can then ask for a meeting.
Basically you want to initially cause the least disruption possible to other people to get your work done. Emails are low-disruption as they can type them up at their desk. Meetings are high-disruption as you are physically pulling them away from their tasks. Between these two are instant messaging and wandering over to another's desk for a quick chat.
Answer: If you're located in the same building, then suggest a meeting to have a convesation about the project. You'll get a lot more covered than a constant stream of emails.
If you just want a few bits of information, then email is fine.
Answer: In addition of what other said.
What i usually use as a discriminant is the fact if the question can be followed by further questions.
if you are looking for a precise thing, e-mail.
if you are looking for an advice or a more complex question, meeting.
Answer:
When it is urgent, call them. An email can be ignored for days and
then forgotten. A telephone call takes conscious effort to ignore.
When it is super urgent, go to their desk. They can't ignore you
without violating social norms.
When you are in a situation where you might need a paper trail to not lose a blame-game, write an email.

When none of these special cases apply: The advantage of an in-person meeting over written correspondence is that the latter allows a far more efficient back-and-forth dialog of questions and answers. When in doubt, rather talk to people than write to them. Written communication is much less expressive than it seems. We don't realize how much we communicate with intonation, and that this information is completely lost in written correspondence.
But how do you know that such a dialog is required to solve your problem?
Ask the receiver.
Explain your problem as good as you can in text form. Ask them if your description is clear enough so that they can write an answer. End your email with an offer to call you or schedule a meeting when they need further clarification.


Is stack overflow reputation actually a Cryptocurrency?

Question: In a way, it is already a currency since I can offer a bounty for my question.
So is it correct to call reputation points from StackExchange a Cryptocurrency?
If not, then why?
Comment: Related: http://bitcoin.stackexchange.com/questions/46408/can-the-system-of-votes-of-stack-exchange-be-considered-as-a-blockchain
Comment: A bounty buys additional advertisement for a question, it doesn't really buy an answer.
Answer: No, it is not accurate to call the reputation system a cryptocurrency.
Cryptocurrencies use a distributed form of updating the ledger of ownership, not controlled by any one person. Stack Exchange reputation points are just an online point system maintained and controlled by the Stack Exchange company. The two are very different.
Cryptocurrencies also typically have a blockchain, and are transferrable at any time between any two persons. With SE Rep, you can only transfer if you do a bounty. And SE rep can be created out of thin air for someone answering a question well. Cryptocurrencies have a supply that is carefully controlled by code, and can only be created by solving a block.
Answer: No, I would say that it is not a cryptocurrency.  However, I can see where there's an argument that it is.
What is usually referred to as "crytpocurrency" is a currency enforced by cryptography.  Since Bitcoin, this term is often blurred with "decentralized currency", which SE rep is certainly not.  StackExchange reputation is in a sense enforced by cryptography, since cryptography is used in the authentication mechanism of the site.
To me, the difference is not in the centralization nor the use of cryptography, but rather the idea that rep is a currency.  Yes, you can set bounties with it...but that's it.  It can only be spent with a single institution, and even more restrictive than that, on a single offering of that institution.  This means it is less of a currency than a gift certificate.  It cannot be transfered to someone in a will, nor is there any exchange for converting it to other currencies.  It cannot even be purchased in the same way that MMORPG currency can be purchased from "gold farmers".
Reputation simply does not meet the criteria for being a true currency.
Here's a couple of nice meta conversations about the topic of buying/selling SE rep:
https://meta.stackexchange.com/questions/30982/how-to-convert-your-stack-overflows-reputation-into-money
https://meta.stackexchange.com/questions/204719/is-reputation-the-currency-of-stack-overflow
Answer: It would be correct to call StackOverflow points a "digital currency", but not a "cryptocurrency" as they don't employ cryptography, blockchain or decentralization -- which are hallmarks of cryptocurrencies.
But, as you pointed out, SO points are digital and can be used to "purchase" the service of online answers.
So they do meet the definition of a digital currency.


Is there an arbitrary precision floating point library for C/C++ which allows arbitrary precision exponents?

Question: I'm looking for an arbitrary precision floating point library for C/C++ (plain C is preferred). I need arbitrary precision exponents. GMP and MPFR use fixed size exponents, so they are ineligible (I have some ideas for workarounds, but I prefer an out-of-the-box solution). It would be an nice feature if the exponent precision can be adjusted automatically to prevent infinity-values.
If you know for sure that such an library does not exist, please say so.
Answer: There is nothing as mainstream as GMP/MPFR as far as I know. But Fredrik Johansson's arb contains a module called fmpr that provides floating-point numbers with arbitrary precision exponents.
Answer: That's a pretty specialized request; without knowing more about your actual needs, I might consider using a more common arbitrary-precision library like MPFR to represent the logarithms of your values (which doesn't quite give truly arbitrary exponent range, but does get you exponents so large that it's probably no longer an issue).
Answer: You might take a look at http://www.ttmath.org/ - I don't think it can adjust precision on-the-fly, but it does support arbitrary precision reasonably well.


Is revealing Internal id a security risk?

Question: We are planning on a mail out with recipients returning completed paper forms, then we'll update Civi with the results.  This is where we have no email address for users.  On the returned form we are planning to print the 'Internal id' of the contact to allow easy update.  Is this considered a security exposure? We don't give access to contacts in Civi - only admin staff have a signon so I can't see that there would be a security problem.  But best to ask & check!
Answer: I think it is a pretty common practice - similar to the way your utility bills have their customer number on them


Is it possible to spoof a successful TCP connection with iptables?

Question: Typically with IP tables you would either drop or reject traffic. For TCP is there a way to have iptables instead send a syn back but forget the connection?
Answer: xtables-addons has the TARPIT target (man page):

TARPIT
  Captures and holds incoming TCP connections using no local per-connection resources.
TARPIT only works at the TCP level, and is totally application agnostic. This module  will
         answer a TCP request and play along like a listening server, but aside from sending an ACK
         or RST, no data is sent. Incoming packets are  ignored  and  dropped.

On Debian/Ubuntu, the package is xtables-addons-common.
Answer: There are several not very nice things one could do; a RST packet could be inserted which unless the hosts involved have unusual and customized firewall configurations the RST will cause the connection to be closed. Another method would be to accept the connection but then somehow remove the state entry; this might look something like
...
-A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp --syn -m tcp --dport 22 -j ACCEPT
...

possibly also with logging (to act on via a log scanner such as sec.pl) or some other module that with conntrack-tools installed runs a command similar to
conntrack -D -s 192.0.2.42

after 192.0.2.42 has connected via ssh to remove the state table entry for that IP.
Comment: LOG, TEE, REDIRECT, etc for another service to handle it is a possibility but I am wondering how to do it with purely iptables as well. Internally it must have the capability if it can RST to SYN instead. It might at least need a counter for it's seq though.
Comment: TPROXY and NOTRACK or even drop/reject on the client's third shake all get very close but still require a tcp endpoint to respond rather than pure client and iptables only.
Answer:
send a syn back but forget the connection?

That means to generate a SYN/ACK but to not track the connection.
Not really, kind of.

First thing first: Why?
If the SYN is to a closed port then either:

drop the packet and avoid any more processing.
if you are going to answer with anything, and the attacker will receive an answer revealing that you are there, then: just answer with a RST. An entirely possible and common iptables answer:
You can send back a RST with iptables -p tcp [...] -j REJECT --reject-with tcp-reset.

If the SYN is to a open port then either:

allow the server (service) handle the request as it see fit.
help the server with a SYNPROXY.
Mitigating SYN Floods With SYNPROXY
Which is actually trying to protect the server against a SYN-ACK Flood DDoS attack. This is not the same as you are asking and it can not be. There could not be two entities (server and iptables) both answering with SYN/ACK at the same time to the same packet. It is either one or the other.

But SYNPROXY is clever. How it works (and a bit more):
When a SYNPROXY is used, clients transparently get connected to the SYNPROXY. So the 3-way TCP handshake happens first between the client and the SYNPROXY:

Clients send TCP SYN to server A
At the firewall, when this packet arrives it is marked as UNTRACKED
The UNTRACKED TCP SYN packet is then given to SYNPROXY
SYNPROXY gets this and responds (as server A) with TCP SYN+ACK (UNTRACKED)
Client responds with TCP ACK (marked as INVALID or UNTRACKED in iptables) which is also given to SYNPROXY
Once a client has been connected to the SYNPROXY, SYNPROXY automatically initiates a 3-way TCP handshake with the real server, spoofing the SYN packet so that the real server will see that the original client is attempting to connect:
SYNPROXY sends TCP SYN to real server A. This is a NEW connection in iptables and happens on the OUTPUT chain. The source IP of the packet is the IP of the client
The real server A responds with SYN+ACK to the client
SYNPROXY receives this and responds back to the server with ACK. The connection is now marked as ESTABLISHED
Once the connection has been established, SYNPROXY leaves the traffic flow between the client and the server

So, SYNPROXY can be used for any kind of TCP traffic. It can be used for both unencrypted and encrypted traffic, since it does not interfere with the content itself.
Having said all that ...
You can not set a SYNPROXY in a port that has no server (it won't work).
So, for closed ports, you need a server, maybe a fake server, but a server anyway.
Python - Scapy - Show all your ports as open
Related:
Syn cookies kind of not work
Comment: As far as I am aware SYNPROXY doesn't actually need a server. The point of it is to not bother the server unnecessarily. So maybe SYNPROXY will work with it behind a block to servers and maybe a block from anything from the client but SYN.
Comment: If you don't mind I'll edit your answer to only the pertinent info. The link you gave is really bad too :D. Very silly stuff like claiming ICPM is never useful and specifying loads of complex rules sometimes rather than just having default drop. They also put in a rule that might not play nice with synproxy (block invalid).


Was it actually possible to change past in Time Lapse?

Question: I have just read about 10 pages worth of explanations of time paradox and what Callie was doing with the photographs in the Time Lapse. However, not a single one could clearly answer the most basic question - could Callie actually change past and save Finn using the machine? If so, how? Considering machine always sent FUTURE photographs?
Answer: From what we see in Time Lapse, I'm pretty sure that time is immutable. The characters kept trying to change the outcome once it started going south, but because their information was limited to a single photograph they had to guess at the events leading up to the picture, which was often wrong and ultimately caused the picture to be correct.
Callie wanted to use the machine to change the past by sending a message to her past self. The problem is, in an immutable timeline, this is impossible. The future has already been written, which is why it can be photographed in the first place. She had already seen the photograph and it had no message. Therefore, she never sent it.
Note that this is similar to the way time works in 12 Monkeys. Cole, try as he might, cannot change the events leading up to the catastrophe that had befallen the Earth. He can't change the past, because the timeline is unchangeable. The best he can do (and his actual mission) is to collect information and possibly a pure sample of the virus so that the people of his time can find a cure.


How conscious are mammals that mating leads to pregnancy and offspring?

Question: Does a pregnant female mammal know that its pregnancy is the consequence of a previous mating? Or are humans the only mammals which are conscious of it?
Comment: Some animals present potential mates with nesting sites; the female chooses the mate based of the suitability of the site. Many females are attracted to mates by specific characteristics before they mate (a present of food to demonstrate hunting prowess, etc.) Some females protect their litters from non-paternal males, but allow the patenal male access. Does this mean anything in terms of consciousness of the result of mating or is it all sub-cortical? We'd have to have some method of communicating with animals to know. Otherwise we risk projecting our beliefs onto the animals.
Comment: Within mammals there is a huge diversity in any trait, including cognition. A dolphin can make concepts connections that a shrew certainly can't. Are you interested to any mammal?
Answer: I have trouble citing the exact source now as it's in one of my books at home, has 'sex' in the title (Sex in History), and I'm at work and can't Google that. But needless to say, the book made mention of studies of isolated, modern human tribes where it was evident that the people of the tribe had not made the connection between pro-creation and child-birth. Rather, intercourse was often tied to specific rituals that had a side effect of birth.
So there are a few things that one can extrapolate from this:

Pre-historic humans may have often not been aware that sex led to procreation
From that one can extrapolate further that no animals have this awareness either, as we are the most intellectual species on the planet

Further, the evolutionary development of sex points to this too. The ultimate cause of child-bearing is propagation, but the proximate cause of child-bearing is pleasure. Before life could be aware of the connection, there needed to be a reason to have sex, and so we would have developed in a way that encouraged pro-creation for no other reason than we liked doing it. Eventually we were bound to connect the dots, but we're oriented for this behavior regardless.
Comment: "The Trobriand Islanders, and some Australians, are reported to be unaware of the causal connection between sexual intercourse and procreation; they are said to believe that spirit-children enter the wombs of women on appropriate occasions, and that sexual intercourse alone is not a determinant of birth." --"Primitive Mentality" essay by Ananda Kentish Coomaraswamy. (By "primitive," the author means, of course, "original.").
Comment: This really cast doubts on (or is casted doubt on by) the concept of paternity. In species where the father expends significant effort for the offspring, I am wondering how this can be motivated without a sense of ownership of the offspring. If such a sense exists, I wonder how it can come about without knowing that the offspring it is born of the father as much as of the mother
Comment: It is completely feasible for paternalistic behavior to exist without being 'conscious' of the connection between mating and pregnancy, but without going further into that in a comment, I'll just say that parental behavior across the animal kingdom is incredibly diverse.
Comment: Wow, I've asked a question about this on another stack exchange. Please if you find the book, I would be very grateful if you gave an answer. See my question [here](https://history.stackexchange.com/questions/34962/are-there-cultures-without-knowledge-of-how-babies-are-made).
Answer: For that an animal would have to know the concept of mating and pregnancy. It's not called the sex "drive" because it requires consciousness in order to mate or become pregnant. It's pretty automatic and subconscious. As any couple that actually tries to become pregnant but can't can probably attest to.
So unless you need to communicate a concept to somebody else you may as well not have a concept. Like those human cultures that only have three numbers. One two and many.


How to delete files and folders in my documents folder without use of FSO command?

Question: I want to delete all files and folders in the My Documents folder. I tried FSO create object command to delete files but not folders in the My Documents folder. Is there any other way to delete files and folders in the My Document folder?
This is my code.
<code>Sub GetSpecialFolderPath()

Dim objSFolders As Object

Dim MyPath As String

Set objSFolders = CreateObject("WScript.Shell").SpecialFolders

MyPath = objSFolders("mydocuments")

Dim FSO As Object

Set FSO = CreateObject("scripting.filesystemobject")

    MyPath = .Range("B2").Value

    If Right(MyPath, 1) = "\" Then

        MyPath = Left(MyPath, Len(MyPath) - 1)

    End If

    If FSO.FolderExists(MyPath) = False Then

        MsgBox MyPath & " doesn't exist"

        Exit Sub

    End If

end sub
</code>
Answer: The code you propose doesn't work.
You need to have two distinct variables for the path you get with
"MyPath = objSFolders("mydocuments")"
and the path you get with
"MyPath = .Range("B2").Value"
Example:
use MyDocumentsPath for the first path and MyTestPath for the second path and then write
"If FSO.FolderExists(MyDocumentsPath & "\" & MyTestPath ) = False Then"
for the test of the directory