What's the significance of Amelia's toothache/jaw pain?

Question: I loved The Babadook. I watched it 2 weeks ago and I'm still trying to take it all in. What I can't seem to understand is, what's the significance of Amelia's toothache or jaw hurting? Did I miss something?
Answer: What I found (from this original source):

The whole concept of disease or illness is often related to emotions which have been repressed. When a person holds in anger, that angry energy has to go somewhere. Some people hold it in their jaw, others in their chest and some in their stomach. Angry energy can actually be held anywhere and everywhere in the body. This energy, if not released, then does violence to the body itself, in the form of disease. So the person that holds in their feelings and does not say what needs to be said, may experience tension in the jaw which can result in TMJ or grinding of the teeth.

You see that in other horror movie like Secret Window. The main character there also displays symptoms of TMJ.
Comment: I think you've got a good start to an answer but the part you've quoted is actually from a different source than the link you've posted here (which is dead now, unfortunately). Plus, the following paragraph relates this concept directly to Amelia in a way this quote does not.  Also, I have no clue what "TMJ" is.
Comment: Sorry if I wasn't clear but what I mean is, you shouldn't randomly use an abbreviation in your answer without explaining what it means, particularly if it's not something that's common knowledge. :)
Comment: The short version http://www.mayoclinic.org/diseases-conditions/tmj/basics/symptoms/con-20043566

The Wikipedia page  http://en.wikipedia.org/wiki/Temporomandibular_joint_dysfunction
Answer: Regarding it not all being in her mind and her son seeing the book too:  I am going to rewatch that scene where they first read the book together because another poster mentioned that the book changes which could mean the book was also all in her mind.  This would mean the whole thing is her own mental illness which she has to keep controlled (looked after by feeding it and soothing it and keeping it locked up safely and contained in the basement).  Her son is close to her and on some level understands her mental illness which is why he talks about it (the babadook) too.  The state of the house and their own appearances also represents the state of her mental health which hugely affects her son as well.
Answer: That explanation works well with my whole theory. She's repressing anger. Extreme anger. I mean her husband died because of her son (in her mind). In the beginning it shows her grinding her jaw. As the "monster" becomes stronger you start noticing her jaw pain. She jolts when she eats ice cream, implying that she chipped a tooth. She creates the monster in her mind. She has extreme sleep deprivation and the monster represents all her anger and frustration. After she realizes that her neighbour exists and says, "I love you both" and her son says, "you're not my mother" and "I know you don't love me, but I love you" she snaps and takes control of her emotions. She keeps them under control, and feeds it (watches after it). It's a British movie, come on. They even say things like look after your temper, mind your temper, etc. Sorry. That was a rant and there are many cool theories about the movie. I'd probably go crazy if I was a single mother with an autistic child that was born on the day that my husband died and I didn't have any release (masturbation scene). I'd at least getting my teeth.
Comment: If course it's not all in her mind. The son sees the book. Unless it was a dream.


Why don't I have Strunk and White?

Question: I noticed on the election page that I don't have Strunk and White, but I would think I should have it.  My user activity page shows that I've done 162 revisions, while the badge only requires 80 edits.  Why don't I have the badge?
Answer: You need to edit separate posts, not make 80 individual edits.  If you've more than doubled up your edits you may need to go a bit farther.
You can check your current progress by viewing the Review page.  Your progress towards your next edit badge is in the middle/lower of the right hand column.
The full requirements can be found on meta.stackexchange.com

Perform a total of 80 edits between questions and answers
Edits on deleted posts do not count
Edits to your own posts do not count
Edits to CW posts do count
Edits that consist only of tag changes do not count
Tag wiki edits do count
Edits you suggest before gaining full edit privileges do count, once approved
Each edited post counts only once, regardless of how many additional edits you may submit
Answer: Have you "edited 80 posts," though?
Based on a quick glance at your revisions, you've made multiple revisions to some posts (not that there's anything wrong with that ;) ), so it's possible that 162 revisions is actually only spread over (for example) 70 individual posts.
I have 228 revisions on Board and Card Games, per the review page, I've only modified 75 separate posts.

Why don't I have Strunk and White?


Can you be resident in several countries at the same time?

Question: During the same year sometimes you live in one country, sometimes in another, have apartment in both, driver licence and car in each country and pay taxes in both.
Answer: Each country defines what it means to be "resident", and for what purpose. Sometimes, a country will define residency as "present in the country for 183 days in a calendar year". Or "6 months", if less precise. Sometimes, a country might define residency as "registered with the local municipality as living in a house". Sometimes, residency for tax purposes is different than, say, residency for qualifying for reduced university tuition rates.
The general answer to your question is yes, you can almost certainly be considered "resident" in two or more places at once. Whether this will be beneficial or not, to you, would depend on which countries and your own personal circumstances.
Comment: for example USA and Canada. And they have tax treaty, so you avoid double taxation.


What are the origins of Deadpool's healing ability?

Question: Was Wade Wilson a normal human (relatively speaking) before being experimented on by the Weapon X program? Did Weapon X give him his accelerated healing factor or simply awaken it? If so, and Weapon X did bring it to the surface, would that imply that Deadpool is in fact Inhuman?
Answer: If I'm not mistaken he was a normal human and that's why when he was diagnosed with cancer he couldn't do anything about it. We don't know that much about his past though, because even he himself cannot remember all of it due to his mental condition.
His healing ability was artificially given to him by the Weapon X and it was this that temporarily arrested his cancer (and could also cure other human diseases).
This ability is derived from Wolverine's.

Deadpool possesses a superhuman healing factor derived from that of the mutant Wolverine that allows him to regenerate damaged or destroyed areas of his cellular structure at a rate far greater than that of an ordinary human.
Marvel.com
Answer: In the movie it says that the weapon X program "wakes up" mutant genes, and that either you mutate or die trying. This means that there are probably some people without these genes that die in the process of trying to mutate, and this suggests that Wade did have dormant mutant genes that were woken up after plenty of abuse.
Comment: Just a note: The facility, in the movie, was never stated nor confirmed to be part of the Weapon X project.


Mochi: pounded vs. from rice flour

Question: Is there any noticeable difference between mochi made from pounded rice, versus mochi made from mixing rice flour and water together and cooking briefly? If not, why bother with the labor-intensive pounding method?
Comment: Here's an article you might like: [Homemade Mochi (pounded rice) the Modern Way](http://justhungry.com/homemade-mochi-pounded-rice-modern-way) He gets into it with a lot of detail.
Comment: My understanding pounding mochi is a traditional activity in Japan. People who make mochi that way may be pounding mochi simply for the sake of pounding mochi.
Comment: I agree with the comment above. The Japanese part of my family on Maui do the rice pounding as a ritual for the young men. I couldn't tell a difference in the final product, but I'm also not a mochi snob.
Answer: A cooked rice grain is not an evenly cooked product... The center has a different consistency to the outside. Pounding the rice would combine the stickiness and would activate rice gluten that is present.
I would assume using rice flour in the recipe would be like using a different grade of flour in a recipe... The texture would be different, more or less sticky, more or less stretchy...
Malaysian cakes are improved by adding different grades of rice flour as well as adding other types of flour to the mix. And freshly made rice noodles made from ground rice; as well as Vietnamese rice paper noodles taste better when the base if 100% steamed rice instead of a mixture of rice and rice flour.
Mochi which is as much about the flavor as well as the texture I feel would benefit from the process as much as the quality or processing.
As an aside, why does hand folded and spread pizza dough taste and feel so much better than a machine made pizza base? Same ingredients, different process no?
Making Rice Paper In Vietnam: https://www.youtube.com/watch?v=HaTr-DPC5yo
Making Mochi in Japan (where would it be without the theatre?) https://www.youtube.com/watch?v=olTuSpJTL2g
Answer: Mochi (mochi mochi, not other kinds having mochi in their name) can not be made from rice flour. Except pounding mochi can be made from shiratamako powder. Difference between rice flour and shiratamako powder is almost the same as between sand and concrete, preparation includes multiple drying and crushing. And for both ways you have to use special mochi rice.

Mochi: pounded vs. from rice flour


Can I build a patio rather than repair a deck with the insurance payout?

Question: Can I build a patio rather than repair a deck with the insurance payout? My deck suffered pretty severe structural damage due to a fire and was built in 1991. Frankly, I don't like the upkeep of a deck. Can I use the insurance claim payout to build a patio? As a follow up assuming the answer is yes, the insurance company withheld part of the claim as recoverable depreciation. Can costs associated with building the patio be submitted and qualify to receive the withheld funds?
Comment: Related but not identical: https://money.stackexchange.com/questions/36203/home-insurance-must-i-use-money-from-a-claim-for-repairing-everything-im-recei .  You probably need to talk to your insurance company to see what they will or won't cover in the future.
Answer: Yes. As a general case, insurance proceeds are repaying you for the damage that you have already incurred, not specifically for fixing anything.
Since you have the legal right to sell the house as-is, without fixing it up at all, then you have the legal right to spend the insurance proceeds how you see fit. You can upgrade, downgrade, alter or replace your deck in any reasonable way... or do nothing.
You should call your agent and make sure that there is nothing unusual in your policy, but this kind of homeowner decision - what materials or methods to fix damage to a home... is very normal and unremarkable, so your agent will probably reassure you and end the conversation without a second's thought.
Answer: Once you accept payment for an insurance claim, the insurance company has discharged its obligation to you.  You could burn the money in a barrel and they would not care.  There is no expectation or requirement that you repair or restore the insured item.  You can do whatever you wish with the money.
Comment: Within reason - if there is a mortgage on the property, there are probably requirements in place that any damage likely to cause a reduction in value of the property needs to be rectified.  In such a case, the insurer pays the money out, but the mortgage company would be the ones to say whether a replacement patio is acceptable.
Comment: In addition to the concerns @Moo notes, insurance providers will not be happy if you make a subsequent claim related to unrepaired damages that they paid for. For example, if you cash their check, but then leave a broken deck to rot, inviting termites to damage the rest of the house. Or a lawsuit when your neighbor's kid injures themselves on the broken structure, etc., etc... In short, you need to clean up the mess, but you should be able to replace it with a similar alternative structure as long as it's constructed properly and doesn't invite more claims later on.


If we were to setup a cannabis store online hosted in Colorado (or any other state), can we legally serve California?

Question: My main question is that since cannabis is still prohibited federally, would be illegal for cannabis sales data and payment processing to cross state lines?
Comment: What does it mean for sales data to cross state lines? I assume you are talking about internet sales and electronic payment processing, but you should clarify what you are really asking. States do not require customers to be local residents, if that is what you are asking.
Comment: No non-cash payment system would do business with a company doing that if they learned it was a marijuana business and there is probably TOS language that says that in their merchant contract. An inability to pay electronically would be a huge problem with this business model. Most internet commerce in the industry is limited to swag, production equipment and glassware.
Answer: No.  As it is an interstate transaction, the applicable laws of sales are the Federal Laws, which still classify it as an illegal substance, and thus, will prosecute for charges related to interstate sales.  In so far as I am aware, all cannabis grown for consumption (as opposed to other utilities, like Hemp rope and oils, which I'm fuzzy on the legal specifics) must be grown and sold within the same state to avoid Federal issues.
That said, if a non-Colorado resident was vacationing in Colorado, they could purchase cannabis for consumption while in Colorado and provided they keep it in the state, are allowed to use it... However, they may not take it home with them (This again becomes Interstate or International and the Feds have jurisdiction over that.).


What property allows ozone to absorb uv light

Question: Why can ozone act as a barrier of UV light, so that we don't get irradiated by the sun's energy, and not any old molecule? In a recent exam I sat, one of the questions was "Name one physical property of ozone and contrast it with oxygen" and under exam pressure I spurted this onto the page: "Because the coordinate covalent bond in ozone is weaker than a traditional covalent bond, the bond is free to 'wiggle' about a bit. This means that the ozone can absorb a range of frequencies of photons, as a completely rigid molecule like oxygen would only have very specific frequencies which it could absorb." How much of this 'guess' is grounded in fact, or in other words, what is the actual mechanism that allows ozone to protect us from UV rays and not any old molecule?
Comment: Now you may think that due to UV radiation ozone layer depletes quickly. But in reality, reverse reaction also takes place. A free oxygen atom combines with a normal oxygen molecule to form ozone. The free oxygen atom comes from decomposition of ozone.
Comment: Ozone is less stable than oxygen. When UV radiation reaches ozone layer, the ozone molecules decompose to form oxygen molecules which are more stable. So even before UV radiation can reach earth's surface, its energy is used up in ozone layer for forming more stable oxygen molecules.
Comment: @Aditya Dev With links and some extra stuff you could make answer with it.
Answer: Shortwave UV light (100-240nm) has enough energy to knock an electron out of an $\ce{O_2}$ bond creating an excited molecule $\ce{O^{excited}_2}$ which decomposes to two free radicals of oxygen. Each of the free radicals then combines with different oxygen molecules to create a net of two ozone molecules.
The crux here is that the electron is not "knocked out" of the oxygen molecule, the electron is just moved to a higher energy orbital of the same oxygen molecule. Since orbitals are quantized it takes a very specific energy to make the transition happen.
Now there is a second reaction. Longwave UV light (240nm - 350nm) has enough energy to knock an electron out of an $\ce{O_3}$ bond creating an excited molecule $\ce{O^{excited}_3}$ which decomposes to a free radical of oxygen and an oxygen molecule.
Thus oxygen protects the ground from shortwave UV, and ozone from longwave UV. Neither alone would protects us from all UV as effectively.
Now the rest of the story is that all molecules bouncing around in the air are not in the same energy state due to atom-atom vibrations. So the UV absorption occurs as a "band" rather than as a "fine line" like in the absorption spectra of an atom in free space.
Answer: Firstly, ozone is an unstable compound and decomposes at about $573K$ to form oxygen. When UV radiation reaches ozone layer, ozone molecules present at the layer absorb its energy and decompose to form oxygen which is more stable than ozone.
One ozone molecule decomposes to form one oxygen atom and a normal oxygen molecule. Hence the energy of UV radiation is absorbed in ozone layer even before reaching earth's surface. That's how ozone layer protects us from UV radiation.
Now, this does not deplete ozone layer since reverse reaction can also take place. That is, high energy UV radiation hits oxygen molecules and each decompose into two free oxygen atoms. Each oxygen atom combines with one oxygen molecule each and forms ozone molecules.
You should also note that the bond order of ozone is $1.5$ and that for oxygen is $2$.
You may also want to read about depletion of ozone layer. Here is a link: Ozone hole
Answer: This is not some intrinsic property of ozone. In fact, any molecule would absorb a range of frequencies of photons. It just so happens that O3 covers the very range that is not covered by other components of our atmosphere, and thus saves us from the detrimental effects of UV rays of that range.
Answer: The reason ozone "filters" UV light at certain wavelengths is due to creation and destruction of ozone via UV light.  This is the reason we have an ozone layer in the stratosphere.
UV light creates ozone at wavelengths less than ~240 nm.  While UV light from ~240 - 315 destroys ozone.  In the process of creating and destroying ozone the UV light is absorbed in those wavelengths.
http://www.oxidationtech.com/ozone/ozone-production.html#answer2


How to call functions from a Smart Contract, without using web3?

Question: I am trying to find out if there is a way to call functions from a smart contract which is already deployed on mainnet/testnet, without using web3. If so, how to do that?
Answer: You might get more specific, on-point ideas if you describe what you DO want to do.
web3 is merely an abstraction of lower-level methods, so yes, such methods exist. Other abstractions exist as well:

other JS libraries
libraries in other languages
JSON RPC which is accessible via curl and tools like Postman
Etherscan and MyEtherWallet provide a UI
Mist can talk to contract functions
You can build your own node to interpret the blockchain and construct an API according to taste

Hope it helps.
Answer: You may use curl to send the request ... an example can be found in this question: "Exceeds block gas limit" error when i try to send transaction via personal_sendTransaction
You will need to properly format the function parameters and it's signature, but that depends on the function you want to call.
Answer: You can call the functions on a deployed smart contract from some websites - for example, using the following steps:

visit www.myetherwallet.com
connect the wallet you wish to send the transaction from - the quickest of these is probably MetaMask, but you can easily connect a hardware wallet. You'll need a bit of ETH to pay the gas cost of the function calls.
On the menu on the lefthand side click Contract
Click the sub-option Interact with Contract

Now on the middle of the screen it asks you for more information about the contract:
 - Provide the contract's address into the first box.
Now to find the contract's ABI... ('Application Binary Interface'):
If you deployed the contract using truffle, the ABI will be stored in the build folder. If this isn't your contract, you can instead usually pull the ABI from etherscan as follows:
 - In a new tab visit etherscan.io
 - Navigate to the contract's page by pasting its address in the search box
 - Halfway down the screen there's a row of tabs, select Contract

Scroll down to find Contract ABI, and copy the contents of this box using the button on the top-right
Now go back to your myetherwallet tab, and paste the contract's ABI into the second box.
Click Continue, and myetherwallet will provide you a dropdown list of all of the functions available on the contract
select the function you want to call, and provide any values required for the function
You'll need to approve the transaction from whichever wallet you connected.

If you didn't deploy the contract, and the contract's ABI hasn't been verified on etherscan, then you may struggle to find it. You may need to contact the person or company who deployed the contract to find a way of interacting with it.


Can one sleep in a room with a tefillin bag/tefillin in the room?

Question: Can a person sleep in a room with their tefillin bag? Does it matter that the tefillin is in the tefillin bag?
Also, if the answer is no, what can one do on Friday night, if one finds out that inadvertently, they left their tefillin bag on the desk in their room? Is the bag a basis for a davar ha'asur and therefore not be able to be moved. We don't really need gufo or mekomo (we would hypothetically need to get rid of it).
Any sources would be helpful.
Comment: Welcome to Mi Yodeya anon! Consider taking the following short [tour](http://judaism.stackexchange.com/tour) to learn more. Perhaps [edit](http://judaism.stackexchange.com/posts/68510/edit) in why you think that sleeping in the same room as tefillin might be forbidden. This provides a starting point in looking for a solution.
Comment: This is perhaps better as 2 questions. One about sleeping and one about moving it on shabbos
Answer: One is permitted to sleep while one is holding Tefilin in a bag (see here, note 12, referencing Kaf Hachayim 44:7). From there it stands to reason it is also fine if the tefilin are on a desk in their bag.
In general one is prohibited from being unclothed in a room with seforim (see for instance here). But it is fine if they are double-covered (e.g., in a bag in a drawer).
Since tefilin are typically "double-wrapped" (the plastic boxes covering them and the bag in which they are stored), it provides an additional reason to be able to sleep in the same room.
Note the Halacha is much stricter for intimate relations in a room with seforim or tefilin (see for instance here 40:2).
As always it is better to CYLOR for a specific case.
Ps. The mukze status of tfilin on Shabbat is complicated, see here note 8 for instance
Comment: This kind of thing is typical if travelling and staying say in a single hotel room. Obviously you can put in lots of layers or wrapping, and possibly a wardrobe may act almost as a separate domain.
Comment: @CashCow I think placing the tefillin in a drawer or closed drawer or your closed suitcase should do the trick. Do I really have to leave my tefillin in the hotel safe while on vacation?


Please identify this LivingTrends plant with a pink flower spike

Question: I recently bought a plant, because it was cheap, had a cool looking flower, and I hadn't ever tried to grow one before. I'm including a picture of the plant below. It is by a company called Living Trends Design. They do have a site, but only basic care instructions for each design they have. They sell some that are meant to hand, some that sit on your coffee table, and like this one it's a small pot with magnets on the back. I couldn't find the names of the plants, though I do have a tillandsia that I got from them. I'd really appreciate an ID of the plant if not the cultivar. Also, some care instructions and potting media info would be great, but if I know what it is, I'll be able to research it or ask another question. Thanks.
Answer: I never would have figured this out if not for that big pink flower spike. I thought it looked like a type of bromeliad bloom I had seen. So I did some searching for pink bromeliad blooms and found this. It is Tillandsia cyanea it's common name is Pink Quill.
Care:
Light: It likes bright light, but it won't tolerate direct afternoon sun.
Soil: It needs well drained soil, a mix of potting soil and orchard medium would be effective.
Watering: Normally water when the soil is somewhat dry, and give it a deep watering until water flows out the bottom of the pot, but I don't think your pot appears to have drainage holes in the bottom. Ideally, it needs a better pot, but short term try to keep the watering a little lighter to avoid the soil staying soaked.
Being a tropical plant it won't do well if the temperature drops below 60 degrees Fahrenheit. When the flower spike dries up you can remove it. All Bromeliads I'm familiar with bloom only once, and the Pink Quill follows the rule. After it flowers it may produce one or several small new plants at the base of the plant. When these are about 3 inches tall you can split these from the parent plant, these may bloom once they establish themselves.
Comment: Thanks GardenerJ. I believe you're correct and thanks for the care advice. I couldn't even think of how to describe it yesterday to put in a search engine yesterday. After posting the question, I added a Google Search By Image ext. to my Chrome browser and did end up finding the name. I definitely plan to repot it. I knew going in that the magnet pot wasn't going to be good for it, but it was a cool bloom and I hope to get some new plantlets from it. Is a tillandsia a bromeliad?
Comment: Yes, Tillandsia is a genus within the Bromeliad Family


Limit to number of parents an object can have?

Question: I have an object with multiple parents to control it. I have a problem though: if I add one more parent object to it, another parent stops controlling it. Is this normal? This is my model:
Each eye is parented to its own empty that rotates it. The reason I did this is because I have a hooked empty on each eye that allows me to change its expression. If I rotated the eye itself, it would distort because of the hooked empty. I parented the eye and the hooking empty to one axis below the sphere so that I can rotate it around the sphere without moving the sphere itself. Now I can only control one empty, or the other. Not both. Is there a better way I could do this?
Comment: I think you'll have to add some explanation of what you mean, because objects can only have one direct parent.
Answer: A certain object can only have 1 parent in Blender. You don't need to worry about not being able to control the object the way you want to, because you can also control the parent objects, and so on and so forth. In my example I parented the hooks of the eyes, in which case if both are moved together at the same time will move the entire eye, to a single empty that will move the eye. I did this for both, and parented those empties to a third empty that rotated them around the sphere. Then I parented that empty to the sphere itself so that when I move the sphere, everything moves. I thus solved my own problem.


Why is a question about the source and level of acceptance of prominent assertion about an historical event "off topic"?

Question: Can someone explain why this question is a request "for trivia or basic historical facts" and this "off topic"? I'm looking for guidance on how I might improve it since it's entirely unclear to me where any of the objections to it are coming from.
Answer: The question is worded in a manner where it can invite multiple answers. That is not in of itself a bad thing, but it seems like you were looking for a specific type of answer, and the question is not constructed to elicit specific answers. Also, as was mentioned in a previous answer to this question, it is not entirely clear what you are asking.
Comment: Specific help in improving it would be appreciated. I'm not sure what's unclear about "What is the source of this claim and how widely is this view held among historians?" The first part proved [easy enough to answer](http://history.stackexchange.com/a/21125/2979) (by contacting the author of the book that inspired the film). The second part could be answered similarly: finding some literature or reference with the opposite view and describing the arguments presented there.
Comment: And I'm a bit confused about how this question differs in any substantive way from most of the questions that show as "Related" there. If anything it is *more* focused and clear (most of those are much closer to "opinion") — and the bulk of the answers to those questions are terrible (almost exclusively armchair generalship or blogging).
Comment: As much as you like to pretend otherwise, it was completely unfocused - the title and the body did not match at all - until the final edit.


Why is MBGP needed?

Question: I've been working on some multicast protocols and I came across MBGP and I want to know why is it needed.
The way everyone uses MBGP is that they set up PIM in every routers, and for the inter domain protocol, they use MBGP.
I don't understand why can'g BGP forward these packets. It's not like multicast packets are different in forwarding than unicast. BGP is capable of forwarding every other packet, why not multicast? Why must we use MBGP?
Thanks
Comment: BGP never forwards packets. It exchanges routing information.
Comment: "_It's not like multicast packets are different in forwarding than unicast._" Multicast routing is very different than IP routing, and it needs to be separately enabled and configured.
Comment: My opinion: There is so much to learn/know, don't get bogged down with BGP unless you find yourself working for a telco/carrier.
Comment: @RonRoyston as a matter of fact, it is about the carrier. it's one of my tasks.
Comment: @TeunVink even better! So it should easily be able to do it for multicast too!
Comment: @RonRoyston Every sample i've seen of MBGP, has had PIM set up as well. So apparently PIM is doing the routing!
Comment: Interesting that you work for a carrier.  Not many people work for carriers.  Well, you will want to dive in and learn BGP in depth then.  Good luck.
Answer: MBGP or Multiprotocol BGP extensions
The first BGP specification was published in 1989, well before IPv6 was created and only shortly after multicast was added to IPv4. Even BGP-4 doesn't support IPv6, multicast or VPNs. Until 1998, that is, when RFC 2283 introduced the multiprotocol extensions. These allow BGP to handle routing information for arbitrary "address families". In practice, an address family is associated with a specific network layer protocol, such as IPv4, IPv6, IPX or AppleTalk. There are also Address Family Identifier (AFI) numbers for tunneling mechanisms such as VPNs and MPLS. A Subsequent Address Family Identifier (SAFI) further specifies unicast versus multicast or more tunneling options.
When routers make a BGP connection, they exchange the AFIs and SAFIs they're prepared to exchange routing information for. If the two routers agree on those, they'll send UPDATE messages containing the regular path attributes with the prefixes (also known as Network Layer Reachability Information, NLRI) and next hops encoded in an MP_REACH_NLRI attribute. Withdrawn routes are encoded in an MP_UNREACH_NLRI attribute.
Comment: BGP itself is carrying the following information that is specific for IPv4 only: Next hop, Aggregator and NLRI. But don't have such capabilities to associate a network layer protocol with next_hop or with NLRI. For this purpose AFI and SAFI fields are implemented in extension of BGP – MBGP. So in case you want to route different than unicast IPv4 traffic via BGP then you need to use MBGP. The routes associated with multicast routing are used by the Protocol Independent Multicast (PIM) feature to build data distribution trees.
Comment: Thanks for the information. I don't have problem with VPN or IPv6. We already have those. My only problem is multicast. I don't understand the need for MBGP. Why can't BGP do it itself?
Comment: So in consequence, to exchange multicast routing information, PIM should be associated using set of AFI and SAFI values in MBGP updates which cannot be done using standard BGP updates.
Answer: One of the most important thing for Multicast protocol is RPF (Reverse Path Forwarding) - this is the feature which would check and make sure that for a coming multicast packet (sent by a multicast source) there is only one route pointing back to the source and this is route is the best, which means that if a router receives a multicast packet from the same source via different interfaces then this router must use only one interface to accept the traffic from, otherwise the multicast packet received from one interface could be forwarded through another and vice versa, thus creating potential loops and increase of bandwidth usage.
Taking into consideration RPF feature, the standard BGP protocol doesn't have the ability to perform RPF checking due to its limitations, while MBGP is an extended protocol which besides previously mentioned AFI and SAFI values has the same standard routing table as BGP:
– Unicast RIB (U-RIB) • This RIB contains the unicast prefixes that was previously used by BGP for IPv4 unicast traffic forwarding.
And an additional routing table:
– Multicast RIB (M-RIB) • This new RIB contains the same type of unicast prefixes contained in the URIB except that the prefixes stored in the M-RIB are used to RPF check arriving multicast traffic.
Therefore this new Multicast RIB can make the multicast protocol working, while standard BGP can't.
We hope this does make sense and has been useful.
Comment: The loops are avoided using MBGP on early multicast routing protocols (PIM-DM DVMRP)
Unlike above protocols, PIM-SM explicitly constructs a tree from each sender to the receivers in the multicast group.
Comment: Thanks. I have a question about this. the loop only happens in PIM-DM, right?

Why is MBGP needed?


Are there programs to program Assembly in?

Question: I have a lot of downtime at school and want to teach myself Assembly, but Command Prompt is blocked on my school laptop. Is there some way I could get around this or some programs that simulate programming in Assembly? My computer uses an Intel Centium processor.
Answer: Lot of times you open IE and type C:\Windows\System32\cmd.exe in the address bar. If your school has not been thorough , you can launch a command window with it.
If not you can try an

online assembly simulator
Assembler IDE/Simulator for beginner
Comment: I think you can probably create a batch file that launches cmd.exe.  That's what I did in high school at least. :P
Answer: Here you go: http://bellard.org/jslinux/ (hope your school-issued laptop has a good browser, though)
See here for tech notes: http://bellard.org/jslinux/tech.html
I assume if you want to learn Assembly you can figure out how to get there given a Linux prompt :)
Answer: You have to be more specific about what kind of assembly you want to learn.
This site offers a NASM and GCC simulator that you can run in the browser
IDE One
I believe MASM has a simulator as well, and can be found in an easy google search.
Another option is ARM, which has an IDE by Keil called uVision, which is a free download.
uVision
There are plenty of different assembly languages..
Answer: I would be curious to hear about your experience using an instruction set and assembly tutorial I put together:
https://github.com/dwelch67/lsasim
I designed the instruction set around common and clean concepts from various processors.  The tutorial is in the form of: just type this code and run it, then I will tell you what it did.
I strongly discourage x86 as your first assembly language.  Try lsasim or msp430 or ARM/thumb or other much better, much cleaner, much more understandable instruction sets, then once you have a little experience with one or a few (msp430, arm, thumb for example) try going to x86.  I have simulators for almost everything I am talking about at github.com/dwelch67.  No tutorials though.  I have a thumb simulator, a subset of the arm instruction set, an msp430 simulator, and I borrowed and stripped down an 8088/8806 instruction set simulator as I believe that if you go with x86 you should start with the basics.  I feel it will make what you see in todays x86 architecture more understandable.
I also feel the simulator approach gives you better visibility into what is going on, and you dont crash or trash your system by trying to learn on it while also using it.
Although, spim is often used to teach asm in school I would also avoid mips as a first instruction set.  It is not a bad instruction set the problem lies in the attitude and approach that the documentation takes.  It was specifically architected for speed for a specific period of history in computing.  Hardware performance at the sake of punishing the programmer, it has a few non-common approaches to things.  I would again recommend going with something middle ground and orthogonal like the ones I mentioned above.
Once you learn one or two of these clean instruction sets then picking up a new instruction set is a matter of syntax.  significantly easier than trying to learn a new programming language.  Each instruction set you learn makes the next one that much easier.  Before long you could be coding in a matter of minutes if you have some examples of the new-to-you instruction set.  In particular if you have a compiler (C, etc) that you can disassemble the output, look those instructions up in the reference material and off you go...


How to easily and cheaply erase a key fob?

Question: I have an old key fob that I want to erase and reprogram to open a lock on our shed. We've had a problem with the neighbor's kids rooting around so we got a lock for the door. The lock came with one key fob but I need two so both my roommate and I can have one. It's a simple key fob: no buttons, just place it in front of the lock for a moment and it unlocks. I have an old key fob that worked the same way that I don't use anymore so I want to erase the information from it and add the information for the current lock. I know how to put the information on there but not how to erase the existing information, which needs to be done before I can reprogram it. I know that if I demagnetize it that will erase the information but I'm worried that that would lead to it not working at all. I can't just buy blank key fobs right now and we can't share the one with our schedules, so what's a lifehack that can quickly, easily and cheaply erase my key fob so it's blank again and I can program it for the new lock?
Comment: Bulk erasing it by demagnetization may destroy the fob formatting as you suspect. Have you tried to record (overwrite) the old key fob?
Comment: What kind of fob?  NFC?  If so, there are many apps out there that will do it for you and you should ask on https://softwarerecs.stackexchange.com/
Answer: You actually want to reprogram a key fob, not just erase (destroy) it. For that, you surely need a dedicated tool (hardware + software).
Before you do anything else, you need to know the technology involved (RFID, NFC, other...) and the details of that technology. It might even happen that your old key fob is not even compatible with the lock.
Sometimes, depending on the specifics of your area, you can find shops doing exactly the job that you want. They have the tools, the knowledge etc. Go there with both key fobs (the good one and the old one) and they will create the clone, if it is possible.


What is the purpose of glScissor?

Question: I know that it is more efficient than stencil test, but am I right assuming that the same functionality could be achieved using projection transformations with viewport?
Answer: They are more complementary than alternatives to each other. You almost always want to set the scissor rectangle to the same values as the viewport.
glViewport() specifies a transformation from normalized projection space to screen space. Polygons are clipped to the edge of projection space, but other draw operations like glClear() are not. So, you use glViewport() to determine the location and size of the screen space viewport region, but the rasterizer can still occasionally render pixels outside that region.
That's where scissor in comes in. glScissor() defines a screen space rectangle beyond which nothing is drawn (if the scissor test is enabled).
So for example, the following code will clear the whole screen, even though the viewport is set to a small portion of the larger window:
glViewport(200,200,100,100);
glClear(GL_COLOR_BUFFER_BIT);

Adding glScissor() and enabling the scissor test (which is disabled by default) restricts the clear.
glViewport(200,200,100,100);
glScissor(200,200,100,100);
glEnable(GL_SCISSOR_TEST);
glClear(GL_COLOR_BUFFER_BIT);

Occasionally you come across an implementation that automatically scissors to the viewport region, but that violates the GL specification.
Beyond that, the scissor rectangle can be used to temporarily restrict drawing to a sub-rectangle of the viewport, for special effects, UI elements, etc.
Comment: to be more clear, `Viewport` clips the vertex calculations. If you draw a line with line thickness > 1 or a point with a `gl_PointSize` > 1 you'll draw outside the viewport as well.
Answer: I like this kind of things explained visually.
In OnpenGL we have 2D coordinates that go from -1 to +1 for both the X and Y axis.

Then this image needs to be mapped to window coordinates.
Let's imagine that we have window that has a dark color as back ground, and we have white as the clear color.
The most common case is having viewport and scissor cover the whole screen.

But we can set them to be a smaller region of the screen.

These regions can be different. In the following example the viewport covers the whole screen, while scissor is the smaller box.

And in this last case scissor covers the whole screen, while viewport is the smaller box. Notice that glClear affects the whole screen, since that's determined by scissor region.
Comment: This is the clearest explaination for me, it really needed drawings.
Answer: They operate at two completely different parts of the graphics pipeline.
glViewport actually specifies a transformation, and it's a transformation that happens after the vertex shader but before the fragment shader.  If it helps to see where it conceptually fits in, think in terms of it being part of the transforms that are used to get your vertex data from world space to screen space (i.e. it's relatively closely related to modelview and projection).
Scissor test happens after the fragment shader, together with all of the other per-fragment operations that happen at that time, such as blending, depth/stencil, etc.  When a fragment is tested by the scissor test, it has therefore already been through the viewport transformation.
Yes, scissor test can be faster can stencil because it's a simple accept/reject based on a fragment's screen space coords, whereas stencil needs to compare with the current value in the stencil buffer, possibly increment or decrement that current value, also take into account the results of the depth test, and so on.
So putting all of that together you can see why scissor test exists.  It gives you the ability to constrain per-fragment ops to a rectangular portion of the screen, but without actually modifying the current viewport transform.
Comment: _"Scissor test happens after the fragment shader"_ — why _after_? Can a fragment shader affect the outcome of scissor test?
Comment: In OpenGL 4.2 or with `ARB_shader_image_load_store`, it is possible to perform some early fragment tests before the fragment shader is run, including scissor: https://www.khronos.org/opengl/wiki/Early_Fragment_Test
Comment: @Ruslan - you'll need to ask the people who designed the API, they're the ones who made that decision.
Answer: glScissors accomplishes clipping of geometry against a portion of the screen.
You would want this, for example, if you were rendering a GUI box that had smoothly scrolling text inside it. You want to clip all geometry outside the portion of the screen covered the by the GUI, but keep partial text or polygons which are still inside.
glViewport maps the projection coordinates to device coordinates, but does not clip.
glStencil is used to mask individual pixels in more complex patterns, such as irregular shapes. Thus, glScissors is faster.
Answer: glScissor is more simple than projection transformations with viewport.
glScissor test specifies what pixels to be changed when rendering, while glViewport changes how gl should map from device coordinates to window coordinates.
Then what's the difference with setting the viewport to the rectangle you want to render to and adjusting the projection matrix to undo the scaling done by the viewport.

What is the purpose of glScissor?


Combining several mask rasters to obtain one single mask with binary values

Question: I have a series of separate rasters which represent the cloud cover over the same area but in different months. Each raster has 2 values: nan for "no cloud" and 255 for "cloud". What i want to do is to create a single mask, where each pixel has a value of nan if ALL the separate rasters have nan as a value for that pixel, and a value of 255 if ANY raster (even only one is enough) has a value of 255 for that pixel.
I'm using QGIS and I guess the raster calculator should be used for this, but I have no clue about how to do it and I've had no luck searching for solutions so far because I don't know how to even call the operation I'm trying to do. I tried to add the rasters but I got a weird result.
Answer: I don't see how you could do that without conditionals, and Conditional Statements in QGIS raster calculator? suggests (and I think too) that the default QGIS raster calculator doesn't support conditionals.
But that link provides a link to RaserCalc, which is another calculator plugin that does support conditionals.
Alternatively, if you're ok with using the GRASS plugin, you could do this with r.series input=your_map1,your_map2,... output=your_output method=average. You could also use the GRASS raster calculator r.mapcalc, but r.series (I think) is or was really just a convenient raster calculator wrapper.
Comment: In the end, I solved the problem by using r.series through Qgis' Processing toolbox, it was the simplest solution but very effective.  Thank you.
Answer: The better way to do this is to set a '1' for 'no cloud' and '0' or 'nan' for cloud. Then you can just multiply them together and all the 1's make 1 and a single 0 sets it all to 0.
@user55937 has the solution, though I think it can do conditionals. Try something like:
not(("Raster1@1" = 255) OR ("Raster2@1" = 255))

which should return 1 if they are all not 255, and 0 if one is.


Is there a difference between "kareis" and "misas be'dei shamayim?"

Question: They sound very similar- is there a difference between them or are they interchangeable and pretty much mean the same thing?
Comment: In what sense/context do they sound the same?
Answer: The Kollel Iyun HaDaf answers your question in its intro to Keritut 2 and lists a number of differences

Some sins are so severe that they are punished with untimely
  death. There are two types of untimely death that are used as heavenly
  punishments: Kares, and Misah b'Yedei Shamayim. Kares means "being
  severed" from the world and dying before one's time. Misah b'Yedei
  Shamayim means "death at the hands of heaven." These punishments are
  not administered by the courts, but through divinely administered
  justice.
One who deliberately transgresses a commandment that is punishable
  with either Kares or Misah b'Yedei Shamayim is punished even if there
  are no witnesses to his act, and even if he was not warned at that
  time of his transgression that his violation will result in his
  untimely death.
The commentaries explain that there are two major differences
  between Kares and Misah b'Yedei Shamayim (see Tosfos to Yevamos 2a DH
  Eshes Achiv; Rabeinu Yonah in Sha'arei Teshuvah, 3:6; Tiferes Yisrael
  to Sanhedrin 9:6):

One who is punished with Kares will die before age 60 (according to Moed Katan 28a, or before the age of 50, according to the Yerushalmi
  Bikurim 2:1). One punished with Misah b'Yedei Shamayim will die after
  the age of 60 but before his time has come (according to Moed Katan
  ibid., or before the age of 60, according to the Yerushalmi ibid.)
When one is punished with Kares, even his children (who are minors at the time of his sin) die, and he bears no further children. When
  one is punished with Misah b'Yedei Shamayim, only he is punished and
  not his children (Yevamos 55a and Rashi there). (See, however, Riva in
  Tosfos to Yevamos 2a DH Eshes, who maintains that Kares only involves
  the death of one's children in the two cases where the Torah adds the
  word "Ariri." However, he might be referring to the death of children
  who are not minors.)
Some add that when punished with Kares, the sinner's cattle and possessions slowly expire until he is left destitute -- see Insights
  to Yevamos 73:2.

For a number of specific sins, the Torah assigns a form of Kares
  in which the sinner not only dies before his time but is not granted a
  portion in the World to Come (Sanhedrin 64b, 90b).

For further research see also here and there
Comment: interesting point about the children. Why should they suffer on the sins of the father?
Comment: @mbloch such a thorough response- *shkoyach* and thanks for answering!
Answer: According to Rashi Kares can fall on the children of the offender and only occurs at the offenders half way point through life. The Ibn Ezra (Breshis 17,14)says before 25 years old  is kares. The Rambam seems to say that Kares only hurts a person on this world.
My source
https://he.wikipedia.org/wiki/%D7%9B%D7%A8%D7%AA#%D7%94%D7%94%D7%91%D7%93%D7%9C_%D7%91%D7%99%D7%9F_%D7%9B%D7%A8%D7%AA_%D7%9C%D7%9E%D7%99%D7%AA%D7%94_%D7%91%D7%99%D7%93%D7%99_%D7%A9%D7%9E%D7%99%D7%9D
Comment: The Wikipedia page says "the *next* world", not "*this* world".


Is there a tool for web based system administration?

Question: What web based system admin tools are there for Ubuntu? Basically I want to setup a headless server at home and want to make it easy for my family to change some settings. I'm familiar with Webmin but want to see what other options are available.
Answer: eBox (now zentyal)
<code>sudo apt-get install zentyal
</code>
https://help.ubuntu.com/10.04/serverguide/C/ebox.html
https://help.ubuntu.com/community/eBox
Note that Webmin is not supported as it's not compatible with Ubuntu package management:
https://help.ubuntu.com/community/WebMin
Answer: Ajenti is easy to install, easy to use and has powerful tools.
Comment: ajenti was a buggy experience for me on a default install of ubuntu 14.04 LTS. had to move on
Comment: Note, that Ajenti is single-server only: http://en.wikipedia.org/wiki/Comparison_of_web_hosting_control_panels
Answer: You can limit what they can access with Webmin.  For others looking at this question, check out webmin.
http://www.webmin.com/
Search for "webmin ubuntu" for instructions on installing because it is not a simple apt-get.
Answer: Zentyal
eBox changed its name to Zentyal recently. They will be coming out with a version 3 soon. It has been under quite a lot of development, and is one of the best administration systems in the market. (Its still free as well).
Blog post detailing the name change.
Answer: Depending on what you want on your server TurnKey may be worth looking at. They have different appliances based on Ubuntu 8.04 using Webmin as admin frontend.


Monopoly cheaters edition

Question: So basically I was playing it with my boyfriend and his mum. I was doing property swap cheat and I took his park lane and swapped it for old Kent road but before someone else rolled I landed on park lane. I didn't know wether to pay the money for the rent or say I had the card so I said I had the card. My boyfriend said that I got caught and had to give the card back because I got caught but I don't think I did. There's no rule about wether you pay or don't pay and say you have it so I didn't know what to do and he says I was wrong but I admitted before he caught me plus what else was I supposed to do. My boyfriends mum agreed with me
Answer: As long as someone called out "Cheat", and explained what you did, you were caught.
This is covered on the first page of the rules:

When you're ready to cheat:

Secretly do what's on the Cheat card. Then you must wait until the next player rolls the dice. If no one catches you before then, you got away with the cheat!
After the next player rolls the dice, let everyone know that you cheated, and how.
Collect the reward described on the back of the card.
Return the card to the bottom of the Cheat deck, and place a new one face up on the board.

How do I catch a cheater?
When you think that someone's cheated, call out, 'CHEAT!', and explain how they cheated before the next player rolls the dice.
If the accused cheat is guilty, they must take the penalty on the back of the Cheat card.
Then return the card to the bottom of the Cheat deck, and place a new one face up on the board.

There is potentially one saving grace here, which is this bit:

If you can't prove that you're innocent, the other players must decide if you cheated, and who deserves a penalty.

So, in the case of a dispute who receives the penalty is up to the other players.
Comment: I don't think the saving grace helps here. That's part of the section about being falsely accused, and she wasn't falsely accused in this case.
Comment: @GendoIkari, it certainly doesn't help if she was being honest, but it is the cheaters edition.
Comment: The rules make no mention of how the person needs to find out you cheated, only that they need to find out before the next turn. Whatever circumstances led to it, the only point that really matters is that he called you out on cheating before the next turn.
Comment: If he did not call out, 'CHEAT!' as the rules describe, then he did not follow the rules as written, and you technically were not caught. However, as with many "Family" games, the rules are a little loose, and one could reasonably expect that if a cheat became obvious the formalities could be skipped.
Comment: Well he didn't notice but I had landed on park lane and he said to give his rent but I didn't know wether to pay or tell him I had to I told him I had it. He didn't catch me cheating I admitted to cheating cause I didn't know what to do
Comment: Well he didn't call me out
Answer: KMR's answer looks correct. I will add that your mistake was announcing that you had the card. It's not your job to make sure you pay rent, it's up to the person who is owed money to ask for it. You could have just not said anything and hoped that the next person continued on.
If the owner did notice that you landed on Park Lane and asked you for the rent; you could have just given them the rent and not said anything. You can't argue that you don't owe rent because you took the deed when your goal is to not let anyone find out that you took the deed. You haven't successfully completed the cheat until your turn is over. The rules aren't clear on who the legitimate owner of Park Lane was for the remainder of your turn.
Comment: Well he didn't notice but I had landed on park lane and he said to give his rent but I didn't know wether to pay or tell him I had to I told him I had it. He didn't catch me cheating I admitted to cheating cause I didn't know what to do. I had already done the cheat before my go

Monopoly cheaters edition


How to grant haste en masse in a mono-green Commander deck?

Question: In my Elf Commander Deck (edited version of the Guided by Nature 2014 Commander Deck), I have Nissa Revane and as I was looking through the MTG tag of BCGSE I saw this question asking about if elves summoned with Nissa's -7 ability have summoning sickness. Since the answer is yes, I was wondering if there is a green or colorless card that I would be able to use to counter their summoning sickness (preferably an elf that grants other elves haste). Is there a card that would be able to fit into the restrictions of my deck?
Comment: One thing to consider, do you need to give the creatures haste en-masse? A [Heedless One](http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=393967) with [Swiftfoot Boots](http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=405406) or a similar artifact would do the trick. Combine with [Wirewood Hivemaster](http://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=43794) and she should get big enough.
Comment: In addition to @ghoppe, you can use [mtg:Ivy Lane Denizen]. He sees each elf entering with him, so you can order the effects.
Comment: Could this question not have been answered trough the use of a simple gatherer search?
Comment: @NeilMeyer The reason why I was asking it on here is because I was hoping for an Elf that would have granted haste (which I did try searching for).
Answer: A simple search for cards with the words "creatures" and "haste" in their text boxes reveals a couple cards with Green color identity that grant mass haste:

Akroma's Memorial is an artifact that grants your creatures Haste, along with a few other abilities.
Concordant Crossroads grants all creatures Haste, not just yours.
Reflex Sliver gives all your Slivers Haste and Hivestone makes all your creatures Slivers, so together they give all your creatures Haste.
Answer: Crashing Drawbridge from Eldraine taps to give all of your creatures haste for the turn.


Why did Abu bakr divourced his wife Kabila, the mother of Asma and Abdullah ibn Omar his wife?

Question: It was said in the Torah, that one may divorce his wife handing her a letter of Divorce, But what was the practice among the Arabs before and after Prophet Muhammad?
Comment: Well the wife abu Bakr divorced was named Qutayla not Kabila https://en.wikipedia.org/wiki/Qutaylah_bint_Abd-al-Uzza and ibn Omar can't have divorced in Jahilya as he was born one year before Muhammad became a Mesenger if you mean his father you may read some info here http://islam.stackexchange.com/questions/35335/did-umar-have-more-than-four-wives-after-muhammad-revealed-the-restriction-on-me
Answer: The only things i could find about pre-islamic talaq is:
That talaq was not limitted so you could speak out talaq as often as you like and could get back your wife as often as you liked. As it seems during the 'Idah. Many spouses used this to hinder the wife to marry somebody else. So they spoke out the words of divorce then right before the end of the waiting periode declared reconciliation before giving divorce again and so on.
Islam made an end to that saying that you may -only- divorce twice with the option of reconciliation (2:229), but if you divorced again this women is free to marry somebody else.
There were also types of talaq which are technically not talaq but a prohibition for the sexual desires and needs of the woman or wife:
dhihar الظهار which means declaring the wife as similar as one of his mahrams, so he would never ever touch her again.
Eyla' الإيلاء which means the husband makes an oath to never ever touch his wife again this would mean that the wife would have to wait at least 1 or 2 years until her husband might again share her bed.
Sources al-mawso'a al-Fiqhiya and this site about the situation of women in Jahilya.
Comment: The question asked-- only-- the "causes" --that leaded to divorce ones wife especially when they are "abu bakr" and "ibn omr". However, when you donot know the answer, then why do you try to answer? I really do  not understand Will you kindly explain?? Your reputation score influence me asking you as I do not answer a question even when I know the answer if  only to that / those questions, upto this day, not answered properly, by the scholars. [See, FARUQUEZ]
Comment: @abuhenamostafakamal your question is not clear as it contains too many errors Abdullah ibn Omar was not even married in Jahiliya. And the wife of abu Bakr which he has divorced was named Qutaylah and yes she was divorced in Jahiliyah. But it seems you mean somebody else than Abdullah ibn 'Omar.  As long as you haven't cleared that any answer would be based on assumptions. There's no information on the way abu Bakr as divorced his wife, but I guess the way of talaq we know now was known in Jahilya but without limitations as quoted in my answer.


"Clip" projector directly to ceiling without "arm-mount"

Question: I would like to install a projector to my living room ceiling. As the ceiling is relatively low, however, I'd like 1) to have the projector "standing" there upside down (in contrast to a mount that takes up another 20cm or so of room height). I held it there and the projection is pretty perfect this way. Heat and air circulation are not an issue. Also, 2) I'd like to use some sort of clip system to slide the projector into and out of if I don't use it. There have to be be some sort of metal plates that can be screwed onto projector and ceiling which fit snugly into each other... some help would be greatly appreciated. Thanks!
Comment: VTC (vote to close) because this is basically a shopping question. Now with that said maybe you want to put on your DIY had and work at crafting up your own brackets.
Comment: @MichaelKaras if you can show me one single projector mount to buy like the one I want to build, I happily agree. Otherwise I'd be grateful if you could give me tips on which tools and material to use to do it myself...
Comment: Did you try googling a "projector low profile ceiling mount"? There are lots of options.
Comment: @Samuel yes I did. Below the ones sold for 70$ and way above there are several suggestions to build you own. Neither the ones sold nor the DIY ones, however, are detachable...
Answer: Just use thumbscrews to attach the projector to a low profile mount, like this one. This approach allows you to maintain the positioning settings of the mount and have the projector free of mounting hardware when you detach it for use elsewhere.
Alternatively, build a small wooden box or shelf and set the projector on it when you want to use it. If you use a shelf like the one pictured below, you can use hooks instead of eye bolts for mounting so that most of the shelf can be taken down when not in use.
Comment: Similar to the low profile you list and show "like this one" image for, was what I was going to post.  They sell on the auction site for about 13 dollars.  Instead of using the side screws to hold the one section to the other one can substitute two detent pins for quick release.  I basically did this for my hanging flat panel in my RV.
Comment: @spicetraders That's an excellent tip. Thank you.
Answer: If it was me working at making a projector mount for ceiling on a DIY basis I would work out how to make an open bottom box that is up in the ceiling between the ceiling joists. Then a platform for the projector is the lower cover for the box and is designed to swing down below the ceiling level using pantograph type arms. Pull down for use and push back up into the ceiling when not in use.
Such type of thing could be trimmed out with nice looking hard wood. For those really into automation a remote control activated motor could be setup to raise and lower the projector.
Here is a random picture capture from Google image search for "hidden projector mount". There a plethora of examples. This first one looks like it may be a commercial product.

This one on the other hand looks very much DIY and was made to pull out from a soffit near the ceiling.


MIMIC dataset : How to find time since first admission

Question: In the process of creating a survival dataset the time to death after first admission needs to be calculated. For patients who are still alive how can the duration-alive from first admission be calculated. In other words from what date should date of first admit be subtracted.
Answer: I will reinterpret your question as "For patients who are still alive, what censor time is appropriate?". The minimum amount of time a patient must survive in order to not have a date of death in the MIMIC-III v1.3 database is 150 days. Most patients are alive for longer: but this is the minimum.


Will someone help me construct a weight loss plan?

Question: I am a 16 year old, American girl who wants to lose weight. Obviously, I am not unique in this regard, but I'm not interested in magic pills and chemicals and Jenny Craig programs that promise results that one never sees. I am about 5' 6.5", or 5' 7". I weigh approximately 172 pounds, give or take a few ounces. I have a pretty average, medium sized frame, I think. My wrists are pretty small and I have naturally very thin legs, but I am not really petite. I am not grossly obese. But I am larger than I'd like to be. I carry my extra weight in my upper body, meaning stomach, back, and arms, but it's strange because once you make it up to my shoulders, collar bones and face, they're pretty slender. I have small hips, my thighs are a rather fat but I guess I'm pretty Apple shaped. I'd like to lose some noticeable weight before school starts back at the end of August because I'm starting a new school and want to re invent my image. I'm tired of being the butt of chubby jokes, but not being fat enough to fit in with the big girls. I'd rather just lose the weight. I'm willing to work hard for it and observe dietary restrictions. I have self control that I pride myself on. That isn't my issue- my issue is that I don't know where to start or what to do. I've received nothing but bad advice from my family. My older sister takes diet pills and my aunt says to eat whatever you want as long as you exercise occasionally. (She has a fast metabolism and fails to recognize that others do not.) If you're reading this, and you've been in my place before and have achieved success, please help me in coming up with a plan. I'd like to lose 40 pounds total before school starts. I know this will be hard but I know that I am capable of doing it because my weight fluctuates between 5-10 pounds without much effort- I just never know what I did to lose the weight or how to maintain it. I never gain a lot- just lose it and then come back up to even. I'm also dedicated and a hard worker who detests quitting. I want to do this the right way. Please aid me in doing so. Thanks a bunch, -S.
Comment: Not to be terse, but start lifting and track your calories. It's really about that simple. https://fitness.stackexchange.com/questions/24495/is-weight-loss-possible-without-cardio/24500#24500
Answer: No one can just 'construct' your diet plan for you. You have to put in the work and learn about the factors that will help you construct your own successful meal plan because you know yourself the best. That being said, I can point you towards some helpful communities where you can get involved and learn about certain topics.
Keto diet - Beginners Guide to Keto: Reddit Keto
Reddit Fitness and basic FAQs: Reddit Fitness
Put in some time and do a lot of reading into those pages to make sure you understand what's going on when you lose a pound of fat. It's not hard, just gotta start. It all comes down to burning more than you consume to lose weight but those links/communities can give you a lot more helpful tips/support than stackoverflow can.
In the meanwhile:

do not drink your calories from now on. Anything with sugar in it (sodas, fruit juices you buy etc.) just drink water.
learn how to use myfitnesspal on your phone and track your calories. See how much you eat normally and see what you can cut back on.
Try to eat less carbs/sugar. Get your veggies in because they're mostly fiber and help you feel full.
Are you involved in a physical activity? No? Start taking some light walks. Great to clear your mind and burn some calories.
Comment: I am well aware of the biochem, thanks. And while fiber makes up the body of many vegetables, almost all the calories are carb based. Rather than present a newbie with your own agenda, it would have been better to present a broad range, and cite better sources than a reddit channel.
Comment: Oh, and as to Lyle, I rather tend to trust research and academia, rather than someone that convinces people that their way of eating is correct, then sells you books on how to do it. Ask a few actual nutritionists about keto for an average person and see what they say.
Comment: So, your first recommendation (pretty much the only one) is a diet crafted to help control epilepsy? And veggies are all calories from carbs predominantly.
Comment: Keto/Atkins was initially designed to help with Epilepsy, yes. However, when you eat a majority of your calories from fat and a minority protein, you achieve a state of ketosis, in which fat is metabolized from your body as a primary fuel source. I would highly suggest looking into Lyle McDonald's works if you want to get into the biochem. Also, veggies are primarily made up of fiber. Fiber (cellulose) is not digested by the human body. I suggested veggies to help satiate hunger for almost no calories (7 cal per cup spinach, 50 cal per 150g broccoli) as opposed to your regular grains.
Comment: Reddit keto is a community of 200,000 plus. Reddit fitness is a community of 6.1 million plus. There are knowledgeable users/mods who keep discussions on check as well as incredibly useful wiki links. I specifically mentioned that no one can construct a nutrition plan for you, you have to do your research. I linked pages that could help guide her. The communities on those pages is great as well. Keto worked great for me (45 lbs over 5 months) and thousands of others.  Instead of being a debbie downer, the floor is open, post something that could help the user.


Ping a sensor for error checking

Question: Is it possible to ping a sensor, like DHT22 or 18B20, to check for connection. I want to do an error check in void setup() and make sure all sensors are connected properly.
Answer: There is no simple "yes" or "no" answer to this.
You need to check the datasheets and libraries for your chosen devices and see what is available.  Many libraries will have begin() function, which may, or may not, return whether the device is working.
Many may just lock up waiting for communication, and there's not a lot you can do with that short of reprogramming the library to work differently.
Some (especially analog sensors) will return values from their reading functions that are far outside a tolerable range that you could assume indicated a malfunction.
For I2C based sensors you could use a variant of the I2CScanner sketch to look at what addresses are in use before attempting to use the sensors themselves.
Other protocols may have a similar system you can use to examine what is on the bus.
Answer: There isn't one answer for all sensors. Some may implement a self-check; if not, an operator could provide a specific environment at startup, which setup() would test for. Otherwise, about all you can do is a sanity-check on the output.
DS18b20 - the Dallas/Maxim one-wire digital thermometer, for example, has a specific value immediately after reset; you could check for that before commanding a measurement. Or simply take a sample and make sure it "makes sense". The specific tests available depend on what a given sensor implements.

Ping a sensor for error checking


Plasma protocol

Question: How this protocol works, simple explain.
How to do the exchange operation on this one?
Best implimentation on your opinion? (subjective ofcouse)
Answer: Let's give this a try.
This is basically how it works:

Whoever wants to start using Plasma for whatever purpose starts a private Ethereum blockchain. This is the Plasma (sub) blockchain. At the same time they deploy a Plasma contract to the main chain - this contract is the link between these two chains.
If you want to use some main chain assets in the Plasma chain you enter them in the Plasma contract in the main chain. These assets get locked in the main chain and after that you can use them in the Plasma chain.
The Plasma chain utilizes functionality from the main Ethereum chain. This happens through periodic "save state" or checksum transfers to the main chain. So at some intervals it stores some sort of state information from the Plasma chain to the main chain (I guess this information can be as simple as a hash representing the latest block in Plasma).
All other transactions happen inside the private Plasma chain. So if you want to send someone (who participates in the chain) some assets you get the assets locked in main chain and you send them in the Plasma chain.
If something goes wrong in the Plasma chain (dishonest blockchain maintainer, participants quitting, something not working) you can always go back to the main chain by using the latest checksum. So you just quit the Plasma chain, provide proofs of this quitting to the main chain along with information about transactions which happened in the Plasma chain and the main chain contract calculates the right state in the main chain.

That last phase is a bit fuzzy for me so here's just my best guess: because the main chain contract has a checksum (a hash of a state from the Plasma chain) but no other information you have to tell the contract which transactions occurred. The main chain contract can verify that these transactions result in the correct hash so they must be what happened and then it can resolve the situation correctly (do whatever is needed to get the main chain up to date, for example Ether transfers).
I don't have an opinion about the best implementation as I haven't really used any of them.

Plasma protocol


Why is sodium such a common ion for in ion tails?

Question: I was doing research about ion tails of planetary bodies and noticed that ion tails composed of sodium were common. For example, Mercury and the Moon both have ion tails made of sodium. Why is sodium, as opposed to other ions, commonly seen in ion tails?
Answer: From http://science.nasa.gov/science-news/science-at-nasa/2000/ast26oct_1/:

"When a Leonid meteoroid hits the Moon it vaporizes some dust and
  rock," explains Jody Wilson of the Boston University Imaging Science
  Team. "Some of those vapors will contain sodium (a constituent of Moon
  rocks) which does a good job scattering sunlight. If any of the impact
  vapors drift over the lunar limb, we may be able to see them by means
  of resonant scattering. They will glow like a faint low-pressure
  sodium street lamp."

Also, relative to other elements, sodium has a low ionization energy.
Answer: Extending @Aaron: Which also does matter, that it is relatively common in the universe ( https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elements ). For example, rubidium has a much lower ionization energy, but it can only be found in traces, while sodium is one of the most frequent elements in the stony planets.


Tag for (whipping) siphon N2O/CO2 related questions

Question: There is a number of questions about soda siphons / pressurized gas techniques. Maybe there should be a tag for those? I'm not so sure about the name exactly, I think whipping siphon might be the general term?
Answer: There has been a tag called whipper for a very long time, although it only has 21 questions, so maybe it was difficult to find.
We now also have a tag called whipping-siphon, which should come up in searches using the word "siphon" only, and I made whipper a synonym of it.


iCloud restore issue on iPhone 4S

Question: I had a minor problem with my iPhone so I decided to restore from the most recent iCloud backup. I assumed it worked much like system restore on my laptop.  After resetting the phone and following the instructions, I began the restore from a backup less than 12 hours old. I got a message saying that there was a problem with the backup and I should choose another source.  I attempted backups from all three most recent backups and got the same message. Is there anything besides a corrupted backup file that would cause this? I do have an iTunes backup but I haven't been as diligent about those since I thought that the iCloud backup was reliable. So if I restore to the iTunes backup I'll lose some data that I really don't want to lose (ideas, work notes, etc.) Thoughts? Suggestions?
Answer: I've encountered a similar error on my iPhone 4S while restoring an iCloud backup. I fixed it by simply updating the firmware/iOS version to the latest version available from Apple. Latest iOS 7.1.2 was out at that time but I was running outdated iOS 7.0.4. Once the phone restored with the latest iOS version, I was able to restore from iCloud. So update your iOS if you're using an older iOS version and try again.
Comment: The phone had the latest iOS and is updated now. Manually reconstructed the phone and apps then did another iCloud backup AND an iTunes backup... the latest iCloud backup failed again. I'd like to recover some notes and voice recordings but I'm beginning to lose hope...will not depend on iCloud backup from here on out. Apple should at least have some way of warning users that backups are corrupted and not useable before you have to use it.

iCloud restore issue on iPhone 4S


Accessing and Multiplying Individual Elements of a Layer's Output in Keras

Question: Problem Description:
I am trying to access the individual elements (i.e., scalar) from a softmax layer's output (with dimension (,2)) and multiply this with a tensor from another model, which has a dimension of (,10). A mock-up digram describing my problem is shown in the attached Figure.
I am using Keras with Tensorflow as the back-end. So far, my approach has been the following: Lets say the output dimension of the softmax layer is (,2) (i.e., a vector of size 2). First, my plan is  to access the individual elements of this vector (tensor according to the Keras/tensorflow) using the keras.backend.gather(a_k_p,0). Where, the variable a_k_p references the SoftmaxLayer.
However, gather simply gives the entire row and does not give the individual element. So, my first question is how to access individual elements of a layer's output?
Assuming I get an answer to the above question, I am describing my idea to multiply a scalar with a tensor as follows. First, replicate this scalar element to create a vector (i.e., a tensor) of size that matches with the DenseLayerA and DenseLayerB (in this case (,10)) and perform the multiplication. Now, I am not sure if this is the right approach since I am unsuccessful in retrieving the individual elements of the Sofmax Layer's output. So, is my approach correct? if not, what is the right way to solve my problem.
Answer: This line of code will select the highest value in your softmax function. If you'd like more than one value just change the 1 to whichever value you'd like. I hope this helps.
top_value = tf.nn.in_top_k(logits, y, 1)


How can I generate a terrain heightmap from the perlin algorithm?

Question: How can I generate a terrain heightmap from the perlin algorithm? I am trying to make a terrain generator (like World Machine). This is the source code I have for the perlin. The only thing that I can't figure out is how to use the perlin algorithm to generate a heightmap image.
Comment: It's hard to say from the question which part of it you can't do. Anyway, it's not like there is a one definite way, actually, it's more of a creative process of fidgeting with stuff and looking at results. Just do it however you like, e.g. you may want to sum noise functions, normalize the results, and the for actual bitmap color do something like `colorForPoint = normalizedValueForPoint * 255 (I presume color is a byte) * brightness`.
Comment: I'm not sure but from the looks of a perlin noise I think highmap is exactly the generated image. I mean each pixel color represents the height of that area.
Answer: A terrain heightmap texture is a regular grid of point samples, which indicate the height at that particular location on the terrain. When you want to create such a heightmap from a function f(vec2), you evaluate the function with the position of each of the grid points of the terrain to get the value at those points, and let that be the color value in the texture.
If the function expects the coordinate in a different space (other scale, offset, range) than the pixel coordinates of your texture, you need to map the pixel coordinates into the coordinate range you wish to invoke the function with.
The output values might have the wrong scale or offset, so you might need to compensate for those by offsetting and scaling the returned value to fit inside the range of values your texture component expects (0 through 255 for a typical 8-bit component):
foreach (y in [0..height))
  foreach (x in [0..width))
    vec2 p = transform_pixel_position_to_parameter(x, y);
    tex(x,y) = height_offset + height_scale * f(p);

Comment: Ok! thanks. I have just a few questions:   1. What is `[0..height]`?    2. What does `translate_pixel_position_to_parameter_space()` return?   3. What does `f()` return?   4. How can I use this code and make a grayscale texture out of it?
Comment: `[0..height]` would be the range of values from `0` through `height-1`. The two loops loop over all the pixels of a particular output texture.
Answer: Your answer might lie in making additive multiple passes:
Pass 1:
Make a 2D array storing values from the perlin generator.  The bigger the array the more detail.
Then scale this array to your maximum/minimum height values for terrain.
Pass 2 through N:
Offset values of array by further perlin generations, with each pass carrying a smaller weight.  This should allow for further detail, taking away from the 'smoothness' of a single pass.

Now the world making suite you mentioned seems (at a glance) to support things like natural water formations/erosion over time.  These can be a bit more complicated to replicate simply, but the general idea is:
Water can only lower/smooth out land, so in any place water must rest, find the deepest point, then create a quadratic gradient outwards (where higher polynomials represent further complexity, drop offs, that sort of thing).
Flora and other plant life can easily be added using rules like:
Plant A can only exist a certain distance from water, and only on a circular area with an average height differential between each point less than a certain amount.
That should make for some nifty looking terrain on the cheap (processor wise).
Answer: Wikipedia about Perlin noise:

The function has a pseudo-random appearance, yet all of its visual details are the same size (see image).

Landscapes have much more varying detail size than Perlin noise, wich is why a single 2D noise used as a heightmap looks unrealistically smooth. You can add additional layers of noise to improve this; a layer with low noise scale also should have a low weight on the overall result height. You can use irregular fractions for the scale to avoid repetitions.
World Machine seems to have a lot of additional features that don't seem to directly rely on only noise, like the valleys perpendicular to the mountains, that may be difficult or impossible to replicate this way.
Perlin noise is also relatively smooth, no matter how many layers you add onto each other, so it can't produce a mountain ridge without running an additional function on the output.


SEO for single-page content-less Web App

Question: as written in the title the website on which I try to do Search Engine Optimization has following two properties:

doesn't have any content in the SEO sense: it doesn't hold any information and only offers functionality
consists of only one page/URL

since most of the SEO tips/tricks I read are based on content, how do I perform SEO optimization on such a website?
for more info: the website is basically just a timer/alarm/stopwatch (http://www.timer-tab.com)
Answer: The usual rules of SEO apply to one page sites as multi-page sites since SEO is mostly per page as opposed to per site. This includes a proper <title> tag,
 tag, etc.
What your main issue is going to be is a lack of interlinked pages. Internal links are very valuable stuff and often overlooked in SEO. But they do transfer PageRank (for Google) and their anchor text is an SEO factor. Without those internal links you are handicapped against multi-page sites.
But it can be overcome. If your timer is very good you should be able to get quality external links to your page which will definitely help your SEO efforts.
Answer: Make sure to put emphasis on perfecting your <title>, <meta>, and
 tags. Thats about all you can do on-site. You might also want to look into Dublin Core and Open Graph tags to give search engine's some more context.
If you want more gritty details, there are sites available that will generate complete reports for you (WooRank comes to mind).
Other than that, you want to do high-quality backlinking offsite. Try getting high PageRank links from reputable sites and blogs. A simple Google search will show you the plethora of services that will do this for you.
Answer: There's no other choice than to get your name out there! You need inbound links to your site, try to reach out to bloggers to talk about your site, start your own blog and talk and link to it.
Get on social medias: Facebook Pages, Google+, Twitter, LinkedIn, etc. Remember to fill out information about your web site.
Search for your keywords and check the results for potential sites where you could ask to get a link back to your site. Find forums where you can get involved in communities that would be interested in your website.
Answer: I am not sure what your goal is but it sounds like you want to game the search engines and I think that is a waste of time. Sure it might work for a while but Google made 500+ algorithm updates in 2011.
If you have something that actually offers value to people then make it available/visible. Tell people about it, make it easy for them to bookmark and share, make connections in the world (even if just contacting site administrators and telling them who you are and what your site does). List your site in the Open Directory Project, etc.
Out of curiosity, I looked at www.brillout.com which led me to www.timer-tab.com. I can tell you that having your
 set to display:none is a no-no (you have hidden text for the purpose of manipulating search engines...on both sites).
You also have the title set to a dynamic countdown so how can a search engine index that?...and what would it index you as?
I don't know if the mixing of microformat markup into the metatags would be problematic or not but I would look into it...
And then an iframe also set to 'display:none.'
Truth be told, I couldn't code a site this dynamic, maybe the things that are hidden are made visible under certain conditions but remember search engines often (more or less) crawl the static site and yours (if it is this app) is a bit thin.
As others have touched on, use the title and description tags judiciously and don't be deceptive, trying to show one thing to search engines and another to users.
I just came back to this question and had a couple more thoughts and feedback.
First, I think you made a slight error in the initial schema.org markup. Your html element currently says:
< ... itemscope itemtype="http://schema.org/CreativeWork/WebApp/Utility/Timer">

I thought it looked overly specific and what I think you meant is this:
< ... itemscope itemtype="http://schema.org/WebApplication">

Right now you are using fictitious microformat markup.
Instead of having this:
<title>Timer Tab</title>
...

Online Web App for Timer Countdown, Alarm Clock, and Stopwatch.

I think you'd do much better with something like this:
<title>Timer Tab | Online Web App for Timer Countdown, Alarm Clock, and Stopwatch.</title>

And for that matter I'd get cut down on 'stopwords' and maybe add something people are likely to search for, like 'free.'
<title>Timer Tab | Free Online Web App: Timer Countdown, Alarm Clock & Stopwatch</title>

Answer: The simplest way to accomplish your task is to:

Create a second page aka. "About Timer Tab". There you do not spam, but put your site mission in clear and concise manner.
Provide meaningful link to the homepage with proper keyword from about page.
Have some valuable resources link to you from their review, e.g. http://bits.blogs.nytimes.com/2011/11/02/asana-introduces-a-souped-up-to-do-list-to-organize-your-work/?ref=technology has link Asana, a Web app.

These steps give you content, internal and external links pointing to your single-page webapp.
Answer: something i would consider is making a small embeddable widget, that someone can place on their site at the bottom of the widget say "stopwatch by brillout.com" or any other keyword that you want to optimise for and have that as a link pointing back to you, this will allow you to have a backlink back to your site.
Its half as effective as it used to be because google has now cottoned on to links like this, but it still holds some value.
Answer: @John his main issue isn't lack of interlinked pages. It will be lack of external incoming links which have more weight than internal links. It's not a theory but if he had 100,000 quality links for a keyword he'd probably rank well for that keyword regardless of copy on the page. That's why Adobe ranks high for the phrase "click here" and the page ranking for that term doesn't even contain it.
So your best bet for SEO to rank high is get a lot of relevant authoritive one way links back to your site. Feel free to also link to maybe one very authoritive site from your single app page.
Answer: The only real & long term way to promote your page is to get inbound links (other websites linking to you) with good anchor text.
For a clear example of this, search for "click here" on Google.
There are so many links with the text "Click here" pointing to the Adobe page, that it doesn't matter that the term "Click Here" is not in the page. It's still no. 1 in the SERPs.
All the <title>,
 tags are nice, but won't do the trick unless they are very uncommon keywords. :)
Answer: Although all this recommendations might improve your overall presentation and score more points. But in the light of  the new changes at google centered on authenticity and the fact that you might run against people that might have this content added you may not increase so much.
Its a question of arithmetic that they will score better, if you do all the things other  than content right you can get 100% from say 15%, but someone that gets 40% from say 85% representing content might get better.
So you might consider adding also content, I see no reason why you should not add a content but visually secondary to your functionality, you can easily add a description, a story and a history. If this is well presented could enhance also the overall experience of your page.
Of course all the advice above are useful (some as how-to other as how-no-to["content-cloaking"]).
Looking at the actual page, is very smooth and although it may seem that adding content might ruin it that, it seem to me that white space is too much and can be filled with content, and you ca also make it move to other free white spaces when the dark-grey moves accordingly with the selected option.
Answer: I think what you are looking for is called " content cloaking".

Cloaking is a search engine optimization (SEO) technique in which the content presented to the search engine spider is different from that presented to the user's browser.
  Here are some useful links:

http://en.wikipedia.org/wiki/Cloaking
This is some information about content cloaking from Google:
http://support.google.com/webmasters/bin/answer.py?hl=en&answer=66355
Comment: "Cloaking" is considered **black hat** and could get your site penalised in the SERPs.
Comment: You are thinking wrong... read carefully the question
Comment: +1 for presenting a true well known black hat technique in an absolutely stoic manner with the intention to help - and even link to an official google page that states that this violates their terms. Sensational!
Comment: Worst advice ever. You should *never* be cloaking.
Comment: lol, sorry about this I totally missunderstood your request, I was thinking that you asked how  can you  present different content for users and google bot.  My point was to illustrate that is a black-hat method and you shouldn't use this.
Comment: This is great, if you're looking for penalties. Content Cloaking is discovered very quickly by Google these days. Even though it's a valid answer, it's still a very bad idea.


Why is there Mold growing on top of my dirt?

Question: I'm not sure what kind of Angel plant this is but it grows mold on the top layer of the dirt after I water it and it dries out. None of my other plants have this issue. Any advice on what I'm doing wrong or what I'm not doing? It's growing fine; but I don't know why it's doing this.
Answer: This is Epipremnum aureum (previously known as Scindapsus) and common names include Pothos or Golden Pothos, or Devils' Ivy. It's not really growing very well, the leaf to stem ratio is poor, so you've got long straggly stems that are not entirely clothed with leaves. It's essentially healthy though, evidenced by the new growth in the centre. I don't know where this pot usually hangs, but if it's well away from a window, it may just be it's simply not getting enough light at the top, and that's caused this effect. I'd also suspect its got insufficient air flow around it, which would encourage the fungal fuzz you're seeing. This can be caused if the plant is hung from a hook in a ceiling that's a dark colour -  plants in this type of pot do better if hung from a wall bracket, which means its not so close to a ceiling.
The other possible problem with this type of pot is that, inevitably and essentially, it has a saucer at the bottom to catch drips of water, but that means the saucer probably holds water for longer than is good for the plant, so the soil may stay damp for quite a while. However, you say the mould appears as the plant dries out, so I wonder what potting soil you used - if it and the pot weren't sterile and new, or it's not good potting soil, there may be woody bits in it that create conditions for the mould to grow on.
I suggest you decant the plant from the pot, take off as much of the existing potting soil as you can without causing root damage, thoroughly wash and scrub the pot, then repot the plant into the same pot using new potting soil. If the white stuff just inside the rim of the pot is hard and crusty, use lime scale remover - I can't tell if it's that or just fungal. I'd also cut back the straggly stems to the rim of the pot, and if you want, root the parts you cut off in a bottle of water. Reduce the length of what you cut off to about 6-8  inches and put the cut ends into the bottle, stand the bottle on a windowsill and keep it topped up with water till roots form, then you can pot those up, or insert them into this pot with the rest of the plant if there's enough root room.
If you've had the plant in a relatively dark, relatively airless place, it will do better hung up somewhere else, but it's hard to comment either way on that, since I don't know where its been all this time.I note also that the soil in the pot is not as far up as it should be - it should come up to just about where the inner 'ledge' is inside the pot, not half in inch below it, so correct that when you repot. Having the soil surface higher means there's more chance of air movement at the surface.
Regarding watering ongoing, water thoroughly when the surface of the soil feels dry to the touch, but not so dry its shrunken from the sides of the pot (there's evidence of shrinking from the sides in the images above, though perhaps that was deliberate to demonstrate the fungal fuzz).
Comment: Hello Lost  in New York! How is your Fiddle Leaf doing these days?  Sterilized potting soil doesn't have this problem...what are you using?  Easy, just rake it a few times and it should go away.  Lots of salts in your water.  That is more problematic than fungus amungus on the top of your soil.  Is this potting soil?  I like Bamboo's information very much...soil surface up to the top of the rim and 1" below.  I think you should purchase a few gallons of distilled water to use after you have repotted in fresh potting soil, scrubbed pots.  Cheap.  I'd be drinking distilled water or well water.
Comment: I see salt buildup, yes? From tap water?
Comment: Hi Stormy, hope all is well. Yes tap water it is. I've been scrapping it out every time I see it. My Fiddle Leaf is so tall and healthy, too bad I cant add the picture to this post so you can see it. I appreciate the advice from both of you guys. I will follow those directions and see how it works out.


What is the meaning of multiple front derailleur clamp measurements?

Question: I am putting a front derailleur on a Surly Long Haul Trucker frame. I know from the LHT specs that the front derailleur clamp diameter should be 28.6mm. However, for the Shimano Deore front derailleur that I want, the online shop gives me the choice of "28.6mm/31.8mm/34.9mm" and "28.6mm/34.9mm". What is the meaning of these multiple measurements, and does it matter which of the two I choose if both include "28.6mm"?
Answer: Those are the seat tube diameters that the derailleur will fit onto. Bicycle seat tubes vary in size for a range of reasons (which is also why we have different size seatposts).
In this case it looks as though one derailleur is giving you a list of three sizes that work, the other is giving a range. I suspect they're equivalent, since the maximum and minimum are the same - I'd be surprised if either of them won't fit any tube between those sizes.
What matters, obviously, if that you buy one that will fit the seat tube of your bike. So either of the ones you've found should work.
Comment: The multiple size ranges types come with adapters. The adapters are made of two piece rings that fill in the space between the too large clamp and the too small seat tube.
Answer: In an effort to not have 16 models of front derailleurs for the same range of price-point bikes, most manufacturers have gone to a larger clamps and shims for the most common seat tube sizes.