Why are vampires not rotten like other undead?

Question: Zombies, mummies, ghouls, skeletons and other undead are usually depicted as rotten, but vampires are always lifelike. What's the reason?
Comment: It might be helpful if you could clarify in what fictional universe you are talking about; not all fictional vampires (or other undead) are all the same.  For example, in the Dresden universe, one of the vampire groups are rotten.
Comment: The specific universe really changes a lot. In some fictional universes, vampires aren't even undead. In others, they're considered undead, but so are other non-rotten creatures such as werewolves and bogeymen.
Comment: Well, vampires need fresh blood to stay alive. I assume therefore that the blood contains some vital ingredient, and that they quickly start to rot if they can't get any. Can't think of a single actual story where that happens though.
Comment: In some interpretations Vampires will become desiccated and enter hibernation if they don't get blood. That isn't exactly rotten looking, but it would still appear dead.
Comment: I did not have any specific universe in mind. My exposure to undead is mainly through various video games, and films and tv like True Blood, Underworld, Blade etc
Comment: Buffy the Vampire Slayer does.
Comment: WarrenP - Terry Pratchett's Discworld has both zombies (eg Reg Shoe) and vampires (eg Otto Chriek).
Comment: Note that this question was closed, yet there is no clear consensus as to whether closing it is appropriate.  Please see [this meta discussion](http://meta.scifi.stackexchange.com/q/9760/1359).  Voting to reopen, as closing it was premature without an appropriate meta consensus.
Comment: has anyone ever read a novel that had both zombies and vampires in the same fictional universe?
Answer: As Hank mentions in this video, zombie creation myths (like superhero origins) are associated with what one fears in the society those myths are created. We fear that zombies will infect us with disease/modified-genes/something else X and this is shown outwardly by their fetid nature; we fear inheriting their weaknesses, often created from our own hubris.
Likewise classic vampires often represented an analogy of the aristocracy, being kept as apart from others. Consider the classic Dracula from Bram Stoker's novel. His 'disease' is one of wealth and status, sucumbing to it is not a matter of destruction but of separation from other humans. This subset of horror is considered 'the sublime', a concept developed in the 18th-19th century.

Burke was the first philosopher to argue that the sublime and the beautiful are mutually exclusive. The dichotomy is not as simple as Dennis' opposition, but antithetical to the same degree as light and darkness. Beauty may be accentuated by light, but either intense light or darkness (the absence of light) is sublime to the degree that it can obliterate the sight of an object. The imagination is moved to awe and instilled with a degree of horror by what is "dark, uncertain, and confused."[5] While the relationship of the sublime and the beautiful is one of mutual exclusiveness, either one can produce pleasure. The sublime may inspire horror, but one receives pleasure in knowing that the perception is a fiction.

Wikipedia
More modern vampires, whilst not 'suffering' from wealth and status are often still loners or those who must stay away from others, lest they take advantage of the less powerful. They are shown to be immensely strong, beautiful or otherwise powerful. If you look hard enough you'll find that (unless I am mistaken) Twilight was first supposed to be a mormon perspective on celibacy; by making this choice Edward separates himself from others (and indeed even from others of his kind, sort of spoiling the metaphor, though the difference between the two are distinct).
Now that's not to say that vampires can't rot, as shown by rcollyer's answer; if the vampires were to rot however, we'd be discussing a different trope, perhaps corruption from power.
In short it's a distinction that writer makes between the horror of those beneath us and the horror of those above us.
Comment: I like the concept of "horror of those beneath us and the horror of those above us"
Comment: Perhaps "Invasion of the Body Snatchers" is the horror of those next to us.
Comment: @Beta I'm not *that* familiar with it, but suspect having yourself subsumed to an alien way of thinking and behaving, would make them 'less' in a certain sense. YMMV.
Answer: This is simply not so. Vampires have often been depicted as corpse-like. Pale cold flesh. Long fingernails and hair, longer than they were in life... as is commonly (but erroneously) believed to happen to corpses in their casket. Barring those stories where they "sparkle in the sunlight", they've been depicted with foul breath, the stench of death, and every other form of corruption save maybe visible decomp. Whatever charms they do have, many authors depict these as some obscene form of mesmerism where their victims imagine (due to wishful thinking?) that they're still alive and ignore all the (to the reader/audience at least) obvious signs that their loved ones are dead and something evil has taken over their cadaver.
In those stories where the lead vampire, a Count-Dracula-like figure, is more publicly presentable, this seems to be mostly the absence of odor and (somewhat) normal behavior. The pale skin is often still apparent to those who bother to look.
You are right that we never see actual decomposition, but then even in zombie movies do we rarely see this. The Dawn of the Dead remake shows victims who are mutilated and still animated, but only in the end credits do we see one that is undeniably rotten and still moving. The Walking Dead television series has shown only 3 that I can think of at this point, and one was only partially rotten (this is important, because in reality the still living can exhibit such necrosis/gangrene). While I do agree that the cliche/trope/concept is of a slowly degrading corpse, that's become a much less popular depiction in recent years as pathogenic explanations are favored above supernatural explanations.
It's debatable even in the traditional views just what the cause is: do vampires decompose at all? Only at a slower (imperceptible) rate? Is this due to their higher level of sophistication (a zombie can't even turn a door knob, but vampires are more than capable of chasing and catching their prey no matter how much they try to evade)? Is the necromancy that brings them to their un-life stronger in the vampire, or does the sophistication alone allow them access to greater magic? Both feed on living flesh, only the favorite tissues differ. It raises all sorts of other interesting questions, like what happens to a zombie after 50 years? Are they animated skeletons? Does the animation slowly give way into something more akin to proper death? We know the answers for vampires (they wait out the centuries), but I'm unaware of a story that answers it for zombies.
Answer: As the comments mention, there is a great variety of different answers to this question, depending on the universe.
In some universes (Twilight and Scott Westerfeld's Peeps), vampires are not actually dead, but are humans who have been modified by biological or supernatural processes. Not being dead, these "vampires" would not rot.
In most universes where vampires are undead, they feed off of living being and so do not normally rot.
As Keith mentioned in his comment, one of the vampire groups in the Dresden universe does rot. Also in the Anita Blake universe there is a line of vampires that can rot and then reform themselves.
In the Anita Blake universe, there is a case of a vampire who falls in love with a human and, out of deference to her, limits his feeding to animals. As a consequence of this, he begin to develop a rotting condition that eventually affects his mind and makes it necessary to destroy him.
In some universes, there are "flesh eating zombies" that, by consuming living flesh, are able to maintain themselves. While their condition doesn't typically improve, they also don't rot any further.
Answer: In the Dresden files, the vampires of the Black Court do decompose. The eldest among them have become completely dessicated, but this is only after rotting which can take awhile.
The other vampire courts operate somewhat differently, and can at least appear completely human. Although, not much is known about the Jade Court.
Comment: Do you have a picture to prove your hypothesis?
Comment: @user973810 no pictures, just good documentation. Bram Stoker, primarily. ;)
Answer: If I may weigh in on this one question here.  I agree with K-H-W in the above answer that is does depend on the fictional universe.  However, according to The Vampire Diaries, if the vampires in this series do not get fresh blood, human or animal - but human is preferred, will begin to desicate - they begin to rot and go dormant until they come into contact somehow with some fresh blood to restore their bodies to their original Vampire form.


Experience with Craniosynostosis?

Question: I'm wondering if anyone has experience with Craniosynostosis? Specifically I'm looking for help explaining and preparing my other children for this surgery.
Comment: It may help you to rephrase the question to ask for help in explaining "surgery" to children instead of a specific surgery process!
Answer: I'm reading your question to say that one of your children is having this surgery, and you're looking for help explaining it to the other children.
The dictionary definition seems helpful, here:
Craniosynostosis [etymology snipped] is a condition in which one or more of the fibrous sutures in an infant skull prematurely fuses by ossification, thereby changing the growth pattern of the skull. Because the skull cannot expand perpendicular to the fused suture, it compensates by growing more in the direction parallel to the closed sutures. Sometimes the resulting growth pattern provides the necessary space for the growing brain, but results in an abnormal head shape and abnormal facial features. In cases in which the compensation does not effectively provide enough space for the growing brain, craniosynostosis results in increased intracranial pressure leading possibly to visual impairment, sleeping impairment, eating difficulties, or an impairment of mental development combined with a significant reduction in IQ.
You can paraphrase that to match your children's age, but just explaining that normal skulls are in separate sections that expand, and what the problem is, and why you want to fix it ought to be a good starting place for a conversation.
Don't be afraid to share facts with your kids!  They just want to know stuff.  No need to scare them with worst-case-scenarios, but they ought to be able to handle the basics...
Good luck!

Experience with Craniosynostosis?


Can MFMailComposeViewController attach an XML doc to an HTML message?

Question: I am creating an email in MFMaiilComposeViewController and if I simply create some html snippets and assign them to the message body - all is well. The resulting email (in GMail and Yahoo) looks like the original HTML I sent.
 [mailMan_ setMessageBody:body isHTML:YES];

On the other hand, if I also include an XML attachment, my email reader renders everything as plain text … including, the XML inlined. IE: my mail client (GMail, Yahoo) shows the raw HTHML and XML tags - including html tags that I didn't supply - ie: the html, head, body tags the iPhone provides around the content:
 NSData *opmlData = [[NSData alloc] initWithData:[opml dataUsingEncoding:NSUTF8StringEncoding]];
 NSString *fileName = [NSString stringWithFormat:@"%f.opml", [NSDate timeIntervalSinceReferenceDate]];
 [mailMan_ addAttachmentData:opmlData mimeType:@"text/xml" fileName:fileName];

I pop3'd the mails to see what was happening and found that WITHOUT an attachment, the resulting html section of the email contains this block:
--0-1682099714-1273329398=:59784
Content-Type: text/html; charset=us-ascii

<h2 style="b

while on the other hand, WITH the XML attachment, the iPhone is sending this:
--0-881105825-1273328091=:50337
Content-Type: text/plain; charset=us-ascii

<h2 style="bac

Notice the difference? Look at the Content-Type … text/html vs text/plain. It looks like when I include an XML attachment, the iPhone is errantly tagging the HTML version of the body as plain text! Just to clarify, technically, both with and without the attachment, the iPhone also includes this:
--0-881105825-1273328091=:50337
Content-Type: text/plain; charset=us-ascii

Notebook
Carpentry
Bathroom floor tile
Bathroom wall tile
Scrape thinset

But this obviously isn't where the problem lies.
Am I doing something wrong? What must I do to actually "attach" XML without the iPhone labeling the entire HTML body as plain text. I tried reversing the assignments (attachment first and then body) but no luck.
For what it's worth, the email looks perfect from the iPhone's sending interface. Indeed, the HTML renders correctly and the attachment looks like a little icon at the bottom of the message. This problem has more to do with what the iPhone is actually sending.
Answer: Turns out - this problem is specific to Yahoo.
On the iPhone, if I change my provider to my Gmail account instead of my Yahoo account, the resulting email has more sections, is much more specific and renders correctly.
Moral of the story - be careful sending attachments from your iPhone via different providers.


Where is the clipboard file located?

Question: Where in the file system is the file containing the content of the clipboard? If there is no file, then how is the clipboard maintained?
Comment: Which version of Unix or which Linux distribution.  Which window manager? You're going to need to provide a lot more information unless this is a general question about clipboards.  What's your specific problem?
Comment: Now I've seen your second question (http://unix.stackexchange.com/questions/255591/how-can-i-copy-the-output-of-a-command-in-the-terminal-to-my-clipboard), I suspect you're just asking the same thing in a different way.  I suggest you close this one and concentrate on the other question.
Comment: How do I close this one?
Comment: Similar question: https://askubuntu.com/q/729360/1073967
Answer: The clipboard is not stored in the filesystem or even in a particular location in memory. In fact, there is no such thing as "the" clipboard; copy/paste is implemented via a communications protocol between applications.
When you copy text in an application (whether by selecting text, for the primary selection, or by an explicit 'copy' operation for clipboard selection), the application where you copy alerts the X server that it now owns that particular selection. When you paste, the application you paste into sends a request to the X server, which is redirected to the application that owns the selection. The data is only ever stored in the source application, and when you paste text, it's communicated from the source to the destination application in real time.
Tools such as xsel, which act as if they're just moving data into a persistent storage space, are faking it; they fork to background to create an X application with no windows, which holds the data to select until it lapses, then exits.
Comment: So by what you are saying, if I close the application I want to copy from, I lose that content?
Comment: Yes. `xsel` gets around this by hiding in the background, and if you run a clipboard manager it'll save it as well, but that's the general rule.
Comment: But that has not been the case for me.
Comment: I killed my graphical session and started another one, and the clipboard did not lose it's content. I am not sure that X died, however it might have, maybe it is saved in on of the gvfs* processes (or dbus?). I went to maintenance target and then back to default. The clipboard was gone. So yes, although you'd expect linux to do something like save it in a file - which would also make it accessible from VTs - it sadly does not.

Where is the clipboard file located?


Calling a script on asset download in Sitecore Content Hub

Question: Does anyone know a way to trigger a script on asset download? Can't find anything in the docs and don't see an obvious trigger condition for that.
Comment: I couldn't find a direct way to do that, but it seems when you select assets and click download a job will be created, so, you could use that, add a trigger on entity creation for M.Job definition, with a condition if the Job.Type is download job, then in the script see how much information you can get from the context.
Comment: Mohammed, that option could work for mass downloads, it won't capture single asset downloads because jobs are not created.
Answer: Asset downloads are logged as an entry in reporting log (event asset.download.completed), these are not stored on the Asset entity so you can't target that operation via triggers.
What you could do is have an external integration (e.g. timered function) that  queries for downloads via Audit endpoint (https://docs.stylelabs.com/content/4.0.x/integrations/rest-api/audit/endpoints.html) and then you process as needed.
e.g.
/api/audit/business/query?logType=reportingeventslog&fullText=asset.download.completed&from=2021-06-21T08:00&take=0
Note: I'm not sure if ALL downloads trigger this event (e.g. mass downloads via UI or downloads via API)


UISearchController with UITableView backed by Core Data iOS 8

Question: Although there seems to be plenty of information on UISearchControllers, many of the approaches I have found have been deprecated in iOS 8. Most tutorials I have found use UISearchDisplayController, which is deprecated, and even the documentation on UISearchController uses convenience methods that have also been deprecated. I'm looking for someone who knows how to successfully search items in a UITableView that is backed by core data in iOS 8.
Currently I have a table view that that fetches and displays points of interest saved from a map view. Pretty standard boilerplate stuff - just persisting and fetching entities. The challenging part of this is adding a UISearchController, which recently replaced the UISearchDisplayController,to the table view that is backed by core data (the tableview displays any  point of interest entity persisted to the data store). Using core data instead of a standard array is where the complication begins, and there isn't sufficient documentation using this particular approach. Open to any and all suggestions.
To kick things off, lets consider that I have stored my fetched items from core data in a mutable array. How would we go about using that to filter our table view?
self.searchResults = [NSMutableArray arrayWithCapacity:[[self.fetchController fetchedObjects] count]];

Comment: Hi.  I think your question, as it stands, is a bit too broad for SO.  Can you elaborate on your particular situation: how is the base tableView constructed; do you want it filtered in situ, or a new tableView presented with the search results?  Which deprecated methods are you trying to avoid?
Comment: There doesn't appear to be any clear documentation once Apple deprecated the UISearchDisplayController. The intent of the question was to be a little broad to open up best practices when adding a search bar to a tableview that has been backed by core data.
Comment: The deprecated method is the UISearchDisplayController, which has been replaced by UISearchController. The problem is there doesn't seem to be any clear documentation for using this with core data. Most of everything that I have found either still uses the UISearchDisplayController, or the documentation focuses on using standard arrays apposed to core data.
Answer: You should be using a NSFetchedResultsController to display your Core Data backed data in a table view. Please read up on that first. Boilerplate available via Xcode templates.
For searching, you can e.g. just invalidate the fetched results controller and let it recreate it lazily. When creating it, add a predicate for the search term.
The UISearchController will simply help you keep track of the usual search event, i.e. search text change, scope changed, cancel etc.
Comment: I've done that I'm talking about filtering the data in the table view
Comment: What is not working? Did you implement the `UISearchResultsUpdating` protocol method `updateSearchResultsForSearchController(_:)`?? You stated explicitly that you were using an array, so I addressed that issue as well.
Comment: I'm working through this and i'll have more to share in a day or so. I currently can fetch and retrieve data, but my problem is filtering a table view. How would you go about invalidating the fetched results controller?
Comment: Your suggestion to invalidate the fetched results controller pointed me in the right direction, thanks!


Diversity of speculative evolution flight mechanics? Attempting to design a megafaunal, aerial diving predator

Question: So, I'm trying to get a concept drawn up for this aerial predator, taking a lot of inspiration from Barlowe's Expedition and its Skewers. I would like to give it a unique mechanism for in-flight propulsion, but I am having trouble thinking of what might fit for it. Ecologically it'd climb to great heights and then dive, potentially using its propulsion mechanism to continually build speed until it finally impacts its prey.
Answer: Sidewinding up through the air.
Sidewinding is a form of locomotion used by certain desert snakes.  A loop of body is stationary on the sand and used as a base to throw another loop of body forward through the air.

In the resultant movement, the snake's body is always in static (as
opposed to sliding) contact when touching the ground. The head seems
to be "thrown" forward, and the body follows, being lifted from the
prior position and moved forward to lie on the ground ahead of where
it was originally. Meanwhile, the head is being thrown forward again.
In this way, the snake slowly progresses at an angle, leaving a series
of mostly straight, J-shaped tracks. Because the snake's body is in
static contact with the ground, without slip, imprints of the belly
scales can be seen in the tracks, and each track is almost exactly as
long as the snake.

https://en.wikipedia.org/wiki/Sidewinding

Your creatures use a similar mode of locomotion, but use control over their serpentine body shape to affect air resistance.  The "stationary" loop is flattened into a ribbon to provide maximum air resistance.  The snake pushes against the resistant flap loop to throw wedge-shaped aerodynamic body parts upwards through the air.  Then those body parts flatten and the previous flattened loop becomes aerodynamic and is thrown forwards.
These snakes climb through the air rather than gliding.  Once high enough they glide downwards in the manner of flying snakes.  Real flying snakes of course must gain altitude by climbing trees.  The proposed animal uses the same undulatory mechanism to "climb" the air.
Comment: This is a supremely novel method of going about it and I really like that. This would work well for more serpentine predators for sure. The initial concept involves a creature with a more wide, triangular, flat body shape, but I forgot to clarify that. Thank you very much!
Answer: Jet propulsion:
If I'm reading your question the right way, you want a propulsion system to increase dive speed, not the ability to climb slowly. For this, aerodynamics are more like a bullet and being light stops being an issue. But impacting the ground at terminal velocity plus whatever speed you can add with your propulsion is a real concern. From the look of the fliers in your example, you seem to be missing the obvious propulsion system.
So let's go with something a little more like a bullet - say, a flying Squid. WHAT?!!? Squid can't fly! Yes, they CAN. Currently, they can't soar like the birds, but there really isn't a lot of pressure/opportunity for that niche. But maybe in your world, there was.
Squid don't have bones (a plus for sudden collision with a prey animal at high speed) but they can have hard parts like beaks and shell. This means they could have a shell acting like a harpoon to impale an animal on impact. With tentacles, they might even be able to use a tool like a stick for this lethal strike function.
Squid currently use water as their propellant for their bio-jet propulsion. If a squid evolved to take up an airborne role, however, they might huff and puff air, and/or reserve water for when they really need acceleration. You could imagine a squid developing a lung to extend out-of-water time, tough skin, and a VERY flat body design that could be reshaped back into a classical torpedo shape for dive bombing. Extend the design: they have been seen flapping their fins, and this could allow for a slow, clumsy ascent, torpedo down for impact (in or near water, ideally) and use their jet in a rocket-like manner (after refiling with water, or just air) to launch themselves airborne again.
But if you don't like squid, then this same propulsion mechanism could be used to suddenly accelerate anything you want to use enough parallel evolution on. So blast off with a jet-powered predator diving faster than anything else on (whatever planet you're using)!
Answer: Sophisticated biological pulsejet. Plus gliding.
What I mean by this is, the picture that you've linked to:

Copyright Wayne Douglas Barlowe 1990
There are intake nozzles clearly depicted, and ridges leading to outputs, out-gassing for thrust.
This implies a method of turning volatile combustibles into a means of propulsion.
I posit that this could be hypothetically achieved by the burning of hydrocarbons in the following way:
First there is the ignition, an oil is secreted into the area after the mouth of the combustion chamber as figure 1:

Wikipedia under CCSAL 2021
The ignition in figure 1 could be achieved through dieseling (the mixture of air and oil is compressed by muscular contractions until it reaches the temperature and pressure required for it to spontaneously combust) like the way a derv engine works.
This starts-up the process, and heats the local tissues of the beast. They contain glands like the preen oil glands of birds which produce oils, rhythmically pulsating to keep the reaction going
Who'd have thought, diesel powered dinosaurs are now to be found in your skies, terrifying the local wildlife.
As an aside, this seems like a (more or less) natural progression of therapod evolution which might happen instead of the boring old flappy  birds we have today.
Comment: I went with a very similar approach, although the pulsejet is particularly spectacular. Wouldn't that be kind of energy-intensive? still, +1
Comment: Not certain about the scale of the thing, also not certain how much fat I'm carrying around at the moment, but if rendered I dare say I'd propel a family hatchback a few thousand kilometers. Suppose all that was in a relatively lean animal the size of a Quetzalcoatlus (or bigger), with all the fat directed into oil glands for propulsion. @DWKraus
Comment: I wonder if you had a lighter-than-air predator with a stabbing weapon, filled with hydrogen. Ascend slowly to height, maintain flight via buoyancy for long periods, then using the gas for acceleration. The body plan shifts from non-aerodynamic (floating) to the smaller, more aerodynamic (diving). A miss could be a real problem, and the time on ground would be very vulnerable.
Comment: True (maybe you can ask a different question using that), but look at the wingspan of the OP's linked image, does it look like a floater or a glider with jets. @DWKraus
Comment: The image is from Wayne Douglas Barlowe's [_Expedition_](https://en.wikipedia.org/wiki/Expedition_(book)), as referenced in the OP, which was published in 1990.
Comment: @notovny Thanks, I'll updated the info.
Answer: How about a gravity bomber?
The organism can be as simple in structure as a gas-filled jellyfish.
It just.... floats around on the wind.
When it detects prey passing below, it farts out its buoyant gas, and plummets straight down like a brick.
Smashes into the prey, and kills it either through impact or via spearlike appendages, or venomous stings like a jellyfish. Then slowly reinflates as it digests the prey, rising back up to await another victim.
Not much in keeping with your vision of a swift apex predator, but it might be an interesting almost-inanimate predator for background color.


ないでいますvsていません-Verb Continuity and Negation

Question: I'm not even certain that ないでいます is used, but if it is, what is it's difference from ていません? They are both negation, but one is saying they are negating, and the other one is saying they aren't doing.
Any help?
Answer: ないでいます conveys that not only one is not doing something, but also one has been in that state for a while (as in, one hasn't been doing it.) In comparison, ていません just says one is not doing something right now.
Therefore ないでいます carries a bit of feeling that one is procrastinating, as in 近いうちに田舎に帰ろうと決めたのですが、できないでいます。(I decided to visit my home town but I haven't managed.)
Comment: There is definitely a conceptual difference between the two, but I think English fails to pick up on it: "I haven't been doing X" vs. "I have been not doing X". The second just sounds like bad English.
Comment: @Earthling, perhaps this is not easily translatable into english, but I do not understand your examples. Could you elaborate?
Answer: (@yadokari)
Suppose that "I have been not eating" were correct English. Then it would suggest that I were in the prolonged state of "not eating", e.g. trying not to eat.
"I haven't been eating" suggests that I happened not to be in the state of "eating" for some period of time. This may be coincidental.
Although it takes some work to see the difference in English, the above example translates readily into Japanese as

食べないでいます
I have been not eating
食べていません
I haven't been eating

For example

断食をしてる間は、寒いと食べないでいるのが特にきつい。
During fasting, when it's cold, then it is particularly difficult to not be eating.

Coming to think of it, I think that the difference in English can be related to the "no split infinitives" rule (which, if I remember correctly, was introduced in the 19th century as an act of arbitrariness to define "proper speech" through grammars, which would distinguish the well-read upper class from simple folk).
The "no split infinitives" rule corrects the above to

... it's particularly difficult not to be eating.

Another rule says that negation should be done on the auxiliary verb (any inflection, in fact). So "to be not eating" negates "eating" directly, but that should be done on the auxiliary verb "to be", whence "to not be eating". But then, the "no split infinitives" pulls the negation out to the front: "not to be eating".
Out of the following, I think only the first is formally correct

○ not to be eating
× to not be eating
× to be not eating

Japanese has no analogous rules; you can negate either part of the ~ている construction.
The nuances that can be conveyed with this construction are described in Kohsuke Kawaguchi's answer.
Comment: you are suggesting ""I have been not eating" expresses volition, but I don't accept this as a certainty. Does the Japanese 食べないでいる necessarily express volition?
Comment: @yadokari I didn't mean to imply that it expresses volition. I said that, _for example_, such a prolonged state of "not eating" could occur when somebody is actually trying not to eat. I didn't rule out that such a state cannot be brought about in a different way. (Compare the other answer, where someone procrastinates visiting his home town.) In any case, I don't think I can say much more about this. I have tried to be as clear as possible.

ないでいますｖｓていません-Verb Continuity and Negation


Example of 1-D Poisson Equation in physics field, engineering field, or others in daily life

Question: In 2D Poisson Equation I have example in electrostatics,
$${\Delta ^2}\phi  =  - \frac{{{\rho _{el}}}}{\varepsilon }.$$
And I need an example of 1D Poisson Equation in daily life. In Engineering field, Physics field, etc. I will try to use a numerical method in that example. Can you help me please?
Answer: It would perhaps not formally be called Poisson's equation in 1D but the question is still valid.

There are many examples within electrostatics and heat transfer. For electrostatics let's say an infinite dielectric plate with one side grounded (Dirichlet condition) and a  charge density at the other end (Neumann condition). To get a source term you can imagine having bound charges throughout the volume- this is a bit artificial but still physically valid. To get a modern touch in this you can pretend that this is some part of a touchscreen device.

In heat transfer the corresponding problem would be an infinite plate with a fixed temperature at one end, such as room temperature, and then a heat flux at the other end, for example Newton cooling. Then you can have a volumetric source term such as from some kind of electric or chemical heating. No matter the source term, in the simplest case the unit of this source term would be the same: power per unit volume; so you wouldn't need to worry about its physical reason.


"Line Intersections" tool does not create point where lines intersect

Question: When I use the "Line Intersections" tool in QGIS, it doesn't create whole intersect points. Also, the gif and picture below show that the lines intersect but the plugin doesn't assign any point to them. How can I solve the problem?
Comment: Select the line(s), if it is one geometry, then you should split it and run the tool again. Otherwise,  the lines probably do not touch.
Comment: Did you run the check validity tool by any chance?  I always do if a tool fails to work as expected since it is quick and easy.
Comment: This line, which is inside the circle is not the polyline.  Also, when we use the v.clean tool in QGIS, the same situation happened and there is no problem with snapping.
Comment: The geometries, you think they are two separate lines, may be one polyline. If it is, the tool doesn't generate intersection points for the lines within the same geometry, even if it contains an intersection.
Comment: If they dont touch, take a look at "Extend lines" or "Snap geometries to layer" from processing toolbox.
Comment: The "Extend lines" tool generates a new layer but when I use the line intersection tool with this layer the result same. The "Snap geometries to layer" tool generates some lines that I don' want nevertheless I used the line intersection tool with this layer also it doesn't generate necessary points.
Comment: I ran the check validity tool. There were 4 intersections with no point generated. There were 3 intersections after using this tool. But it doesn't generate for all intersections.
Comment: Cross-posted as https://stackoverflow.com/q/69539559/820534
Comment: Another possibility is described [here](https://gis.stackexchange.com/questions/263103/creating-vertex-where-two-lines-meet-using-qgis/263140#263140): use v.clean [Grass]
Answer: Probably in the cases where you don't get an intersection, probably the lines do not touch or there is a snapping issue like this one. There's probably a (very tiny) gap- so small you don't see it. The solution is to make the lines a tiny bit longer: to extend it using QGIS expression extend.
You can test it by applying an additional Geometry generator symbol layer, rendering as point and using this expression:
intersection(
    $geometry,
    difference(
        collect($geometry),
        $geometry
        )
    )

Than change this expression by replacing $geometry in line two by this: extend ($geometry, 0.1, 0.1). With this, you make your lines a tiny bit longer (by 0.1 map units - change this value if needed). In this case, you get additional intersection points where the initial lines do not touch.
When satisfied with the result, you can convert it to actual geometries (new layer) using Geometry by expression with the same expression. Run Multipart to single parts on the result.
Left: one line does not intersect the others (red circle); Right: with the revised expression, you also get a point there:
Comment: I used the snapping tool and also I checked the intersection without point there is no problem with snapping. I zoomed enough. I applied your solution. It generates some points but also line intersection tool generates them. Your solution does not generate any point that. line intersection tool does not generate too.
Comment: Can you share your data (or a sample of it), containing the problematic spots?
Comment: https://github.com/aycatbkoglu/QGIS-Intersection-tool-error-dataset our dataset is in the repo
Comment: I downloaded your files and applied the first expression from my answer (without extend_line): all intersections show correctly, see: https://i.stack.imgur.com/kjnue.png - did you try this solution? It should return all intersection points correctly
Comment: Line intersection tool indeed does not generate all points, even if they seem to be snapped. However, QGIS seems to have a snapping problem sometimes, see this: https://gis.stackexchange.com/a/379655/88814 . The solution here is to extend the lines a little bit: with that, even the Line interesection tool creates all correct points.
Answer: This is a very common issue in GIS. In the case of your data, it occurs because the vertical line doesn't have a node that matches the final point of the diagonal line, and due to geometric non-robustness, the geometry engine fails finding an intersection there.
Solution
You need to make sure the layer has a proper topology before running the Line intersections algorithm (it means, either modify your original layer or run the Line intersections over a modified copy of your original layer). In practice, just follow these steps:

Run the Snap Geometries to Layer with the following parameters:

Same input and reference layers. The tolerance is up to you, but a tolerance of 1 mm. works well for most cases (planar coordinates). Regarding the behavior, you can choose the second option, called Prefer closest point, insert extra vertices where required (it's important to choose one that inserts vertices).

Run the Line intersections algorithm using the output of the step 1.

And that's it. Doing that you'll get the point intersections you expect.

Tip
I suggest you to build a model like the following, so that you get what you want in one go. Anyway, you'll probably need to remove the duplicated intersections the Line intersections returns.

Note 1: The Snap Geometries to Layer algorithm has been heavily optimized and adjusted lately (see https://github.com/qgis/QGIS/pull/42781 and https://twitter.com/GeoTux2/status/1435136250487480320). So, you need to use QGIS >= v3.21.x. QGIS 3.22.0 will be released in 9 days, but you can download a nightly build if you cannot wait until then.
Note 2: Fortunately, GEOS v3.9 solves this issue of geometric non-robustness. Therefore, as soon as QGIS upgrades GEOS to v3.9, we'll be able to see the expected results without intermediate steps (like running Snap Geometries to Layer). Since these thing don't happen automatically, you could get involved in the project. Sometimes an effort from the community itself is needed before such changes happen (e.g., via funding).
Comment: Could you elaborate a bit on the robustness aspect? Basically, it is due to a rounding issue that snapping does not always work as expected, is that correct?
Comment: I tried your solution with the dataset provided by OP. I used the very settings you propose for the 'Snap Geometries to Layer' tool, however, line intersection on the modified layer still doesn't find all intersecting points. I increased tolerance to 1 m, still with the same result. Using QGIS 3.20.0 with GEOS 3.9.1-CAPI-1.14.2. Using the extend line solution works with OP's (unprocessed) dataset, even the simple intersection operation with QGIS expression works, without extending the lines.
Comment: @Babel, the answer says that you need to use at least QGIS 3.21 (dev version). Yes, that's also something I explained in the answer, GEOS 3.9 solves the issue, see Note 2.


Is there a way to stop the tabs on a WPF .NET TabControl from changing positions?

Question: I have a VB.NET WPF TabControl (with 8 tabs - 2 columns, 4 rows).  When clicking on a tab, that active tab always jumps to the top row.  Is there a way to prevent this and lock the tabs in the position set at design time?  I cant see any properties on the TabControl or TabItems that would allow this.
Comment: @BigDaddy If you size it down that the headers wrap it does do that.  But there is no set rows and columns to my knowledge.
Comment: What do you mean 2 columns 4 rows?
Comment: Post your xaml.  It's hard to visualize what you're describing.  The default behavior of the TabControl isn't like this.
Comment: Override the template. The template *mst* contain this logic. Look at the original template.
Answer: Usr is correct; you will need to override the template (at the very least) if you want to stick with using the TabControl.
There is an example of overriding the TabControl template here: want to make scrollable tabs for a tabcontrol
That link describes how to put in scrollable tabs, if that is an option you would like to consider. That doesn't seem to answer your immediate question, though.
Another option would be to write your own tab panel. You would still need to override the template as in the example, but instead of where it says "TabPanel" you would reference your own, custom tab panel.
The last option I can think of is to have a grid of buttons where each button simply changes the visible content, instead of using the TabControl. Essentially, you'd be implementing a fake TabControl. It might be a simpler project than trying to override the TabPanel, depending on what you are doing.


Refrigerate Cookie Filling with heavy whipping cream?

Question: Is it necessary to refrigerate cookies that have been filled with icing of heavy whipping cream, butter, and milk chocolate chips?
Answer: Your ingredients imply that you are working with some version of ganache (or truffle filling).
The lighter kinds, with a lower chocolate  and higher milk or cream content will need refrigeration. Very high-chocolate versions can be held at cool room temperature for a limited time.
Without further examining the recipe and method, food safety considerations mean we can only answer your question with:

Yes, the cookies need to be stored in a refrigerator.


Convert shell logs (incl. escape characters) to HTML?

Question: Is there tool or a regexp that can convert shell escape characters to HTML code?
As an example, here is a logfile from GNU screen:
^MESC[K$ ^MESC[K$ exit
Executing .bashrc
ESC[00;31;31mserver.xyz.com: ESC[00;34;34m~

which I would like to convert to something like this:
$ exit
Executing .bashrc
server.xyz.com: ~

and send as HTML e-mail to an e-mail address, to archive my work.
Here is a related question, which shows how to convert it to regular text, but it would be nice to convert to HTML and not just throw the escape characters away.
Answer: The query you need is convert ansi to html.  Here is a Perl package that seems to do it.


What is meant by the rest energy of non-composite particle?

Question: When talking about the rest energy of a composite particle such as a proton, part of the rest energy is accounted for by the internal kinetic energy of its constituent quarks. But what is physically meant by the rest energy of non-composite particles such as quarks?
Comment: The energy obtained by turning the quark into pure energy (eg light &c). I guess you already know this, though.. I think rest energy is just another property you take for granted (no intuition behind it), like the spin of an electron..
Comment: Related: [What defines the mass of elementary particle?](http://physics.stackexchange.com/q/6461/2451)
Comment: Note that the valence quark masses make up several percent of the proton's mass.
Answer: One has to be familiar with four vectors. In the same way as for three vectors the length is an invariant of the vector and is obtained by the dot product of the vector with itself, the "length" of the relativistic four vector is the rest mass, by definition;
the mass $m$  entering the relativistic equation where $p$ is the momentum and $E$ the total energy,
$E^2 - p^2c^2 = m^2c^4$
when $p=0$  is the rest energy.
In a composite particle the invariant mass even when it is at rest is the invariant mass of the four vector composed by adding the four vectors of all the constituent particles . A composite particle displays an effective rest mass.
For a non composite particle, as the electron, the energy when at rest, $p=0$, is its mass.


iPad 2 deleted notes - how to find

Question: I have a problem with "NOTES" on my iPad. I have missing notes that appear to be deleted. I have been trying to get on to iCloud to see if I can find them ther, but I can't seem to login. I'm going through a divorce & have important notes. It seems like my wife has somehow logged into my iCloud account & deleted them. Is ther a way to find them?
Answer: The simply answer is, unfortunately, that it will likely not be possible to recover notes that were deleted through iCloud.
Your only possible way to recover the notes would be if you have Time Machine backup on a OSX computer that is logged into your iCloud account. Honestly, even for this to work would be highly unlikely.
In the future, check out Evernote, or Google Drive to store your important notes.

iPad 2 deleted notes - how to find


Sentient parasite

Question: Realistically, how could a parasite become sentient? It doesn't have to be one that can control it's host like a yeerk from Animorphs, but that wouldn't be a disqualifying factor.
Comment: The modern, domesticated housecat is, impo, the most advanced parasite in the universe outside of ideological possession.
Comment: Sounds like a bad idea, since being sapient means your brain needs to be big enough and consumes a ton of energy, and if you ask me, a larger parasite that is depleting the host's resources faster isn't filling in the niche as well as the simple tick with a tiny brain which isn't stealing as many nutrients and resources and can stay hidden more easily. If you want an example of what it could be like just look at vampire bats, which are plenty smart already but certainly not sapient and will die in about 2 days if they don't have a proper meal until then, and they're 10 cm long.
Comment: I assume you mean sapience instead of sentience. There are a lot of things working against you. Parasitism tends towards being very specialized, very asocial, and very static and stable living conditions all of which negate the need for intelligence.
Comment: Semi-realistically... Would you categorize a Vampire as a predator, or a parasite? They are supposed to be very smart. There is no rule that a parasite must be a mostly sessile organism, bound to just one host.
Comment: @OscarBravo - We predator, not parasite.  It is ludicrously rare for a parasite to drive a single species extinct, much less dozens.  In general the population of parasites lags the population of their food.  When food is abundant, parasites become abundant, but when food is scarce, the parasites die off.  Pinnacle predators, or super-ultra-mega-predators, like humans, on the other hand ....
Comment: [Vaguely related](https://medium.com/universe-factory/and-psithyrus-beat-his-time-eaeb2e64b3ca)
Comment: https://animorphs.fandom.com/wiki/Yeerk
Comment: PcMan, good point. I should have clarified.
Comment: Realistically, why should a parasite not be sentient (or sapient)? If you're suggesting all parasites must be unintelligent, where does that come from?
Comment: Wasn't there a really awful TNG episode that went into this?
Comment: @EngrStudent I'll see your housecat and raise you humans.. We efficiently parasitise nearly every other species on the planet. Not sure we're all that sapient though...
Answer: Intelligence came first.  Parasitism came later.
Your species starts as a small meerkat-like carnivore that lives in groups - social cooperativity and intraspecies competition leads to intelligence.
A subset of this species associates itself with large herbivores.  In addition to catching and eating creatures flushed out by the big grazers they clean the herbivores of ectoparasites.  Some of these ectoparasites seriously decreased the genetic fitness of the big herbivores so that is a serious win for the herbivores.
Some of these creatures in addition to cleaning off parasites take a sip of blood or meat themselves.  Over time this subset does less foraging and more sips of blood and meat from large animals.
This subset gradually evolves to complete parasitism of their original hosts and others.   Body size decreases and they become stealthier.   The intelligence evolved by their ancestors persists, but in a degraded, degenerate way.
Comment: Interesting evolution line. Maybe I can use that with some modification.
Comment: The best parasite never surpasses the host. I really do agree with you about the degenerate form of intelligence, because being a parasite means you can stand on the back of the cow, but you could never fly like an eagle. Overtime, because the car was doing all the hard work, the parasite becomes a smaller and smaller thing. If it's big enough that I can go head to head with a cow, the cow is probably a lot more involved at butting heads.
Answer: Realistically, unless the parasite can generate and perceive radio frequency signals, and therefore communicate 'telepathically' with other members of its species, there is little reason or opportunity for a parasite to become sapient.
Parasitism typically requires that the parasite lodge itself somewhere on or in its host's body, and simply attach and begin feeding, none of which requires much in the way of brains.  Since the parasite doesn't kill its host, it remains up to the host to feed itself and its parasite.
The only likely way that a parasite could become sapient is for it to evolve to use its intelligence to assist its host, in which case it is no longer really a parasite but rather is a symbiote, or for it to use some long-ranged non-line-of-sight communication method to communicate with others of its own kind to their mutual benefit but not the host's benefit.  Such communication abilities are unlikely to evolve except on a world where organisms incorporate metals into their bodies.
Since parasitism imposes selection pressures minimising the impact upon the host - at least until it is time for the parasite to reproduce and have its offspring parasitise new hosts - the selection pressures are typically those encouraging simplicity over complexity, and low energy over high, and sapience is typically both complex and energetically demanding.
Comment: @RossPresser Vampire bats **are** parasites; the only known parasitic mammals. They practice micropredation, a form of parasitism. https://en.wikipedia.org/wiki/Parasitism#Micropredator
Comment: @ceejayoz Curious, sincere question: are humans then practicing micropredation when we milk cows or shear sheep?
Comment: Would a vampire bat count as a parasite?
Comment: Very well. Today I learned.  Deleting my mistaken comment now.
Answer: Spreading and feeding
There is much literature and other media like games where you can see why parasites would want to get smart, even if it isn't said explicitly. This also has a evolutionary perspective, which we can actually see in nature. Like all organisns they want to spread.
Parasites exist in many forms. From fat worms that can become several meters long to viruses and bacteria. Some use existing 'biological infrastructure', like feeding, breathing or excrement, to spread. But some use some extra assistance to either protect themselves or help spread. A bacteria that uses cats to multiply can infect mice and make them lose their fear for cats. Rabies can cause fear of water to such an extent that spasms are triggered when trying to swallow. Cordyceps will influence ants or other insects to move to certain locations, grip until they die and then the fungus will grow out and spread. Each is a mechanism to control. This control is to try to spread better or for defence.
From there it really isn't a big leap for a parasite to start controlling more and more of the actions. First it might be to spread better and better, but at a certain moment the host might be more protected as well. The longer the host survives, the better it can spread. The parasite would start to improve food intake and possibly blend better into the society it works in, so it won't be rejected by other potential hosts and can stick around. The intelligence might not come from the parasite, or at least not at first, but might gain this ability at a later stage.
After a certain amount of control is established, the parasite/host organism can nearly be seen as one entity. That means that, if applicable, intelligence is the right strategy for further evolution. Meaning they can take the same evolutionary path as humans, because it benefits them.
It is a long, complex road to such parasites and they likely only infect one or two species at first. It is unlikely. On the other hand, humans getting this much intelligence was also unlikely. We see it could happen with humans, so the same could be valid for parasites.
Comment: The difference between a change in the host's behavior and the parasite becoming a symbiotic co-processor is quite significant, and the selection pressures on parasites are counter-complexity in nature - a small, simple,  low-energy parasite is less likely to kill its food supply than a large, complex, high-energy parasite.
Comment: @MontyWild♦ the same selection pressures can be said for complex multicellular life in general, or intelligence specifically. In times of abundance it can still arise and proof worthwhile for any organism.
Answer: Animal Husbandry based Parasitism
Humans used our intelligence to domesticate various animals such as goats, sheep, and cows. To these animals who we use for milk, we are by every definition parasites.  In some cases, humans like those of the Steppe peoples have also been known to drink the blood of their horses while riding them.
Comment: In the general case it is a symbiosis.
Comment: Sentient parasites would go a long way towards enabling symbiosis since they won't want to depend on the randomness of their hosts.
Answer: Others have gone into detail about evolutionary factors which work against the evolution of higher intelligence in a parasite.  There are still ways for parasitic life to "find a way."
Another scenario which may work in conjunction with Willk's idea.  Perhaps parasitism is only one stage of the life.  Or perhaps the parasite lives inside a creature large enough to provide enough calories to support the parasite's sophisticated nervous system.
Comment: Hello! When answering questions it is often a good idea to provide resources or links to help further explain your response.
Answer: The book "Parasite" by Seanan McGuire (author of somewhat schlocky urban-fantasy) has genetically engineered tapeworms doing this. Everyone has one now and they keep you super-healthy with their ability to adapt.

But in rare cases, especially for a brain injury, they can spread to the brain, "adapt" to it and accidentally take it over. Of course it's like a new brain -- they have to learn how to walk and talk, but are fast learners.
Comment: Preceded by [Futurama](https://www.naturalblaze.com/wp-content/uploads/2019/01/yo-worms-image-2018.jpg).  And *[Blood Music](https://en.wikipedia.org/wiki/Blood_Music_(novel))* too.
Comment: @RossPresser Those Blood Music things seem like simply nanobots (yes, yes, at the time it was new), whereas tapeworms are actual parasites and they themselves get smart. BloodMusic make it sound as if the humans become more intelligent with nanobot help.
Comment: Well, for most of the book the viewpoint is that of the humans, and the Blood creatures just seem like an alien invasion, albeit one that improves human individuals. But one of the threads of the story follows a human who is fully downloaded into cells, conscious, and meets others. They aren't human minds exactly but they are minds, not just machinery.
Answer: Perhaps a parasite that integrates with the brain/nervous system, like a Neural Parasite from star trek, could become sentient upon integrating with the host.

Sentient parasite


normal bundle on a submanifold

Question: Can you give me an example of a nontrivial normal bundle of a submanifold (of any manifold)?
There is standard example of the core circle of a mobius band, but can you give an example of a submanifold of an orientable manifold?
Comment: Do you also want the submanifold to be orientable?
Answer: Proposition: Let $M$ be a submanifold of $N$, where $N$ is orientable and $M$ is not. Then the corresponding normal bundle is non-trivial.
Proof: Suppose the normal bundle is trivial, then it has a global frame. This frame, together with an orientation of $N$, induces an orientation of $M$.
In view of the above proposition, you can take any non-orientable submanifold of $\mathbb{R}^n$, for example an open Moebius band inside $\mathbb{R}^3$ or a Klein bottle inside $\mathbb{R}^4$.
Answer: I assume you don't want to consider points. Take any manifold $X$ which isn't stably parallelizable, e.g. because one of its Stiefel-Whitney classes or Pontryagin classes doesn't vanish, and embed it into a manifold which is stably parallelizable, e.g. $\mathbb{R}^n$ or $S^n$. Then the normal bundle cannot be stably trivial, and in particular cannot be trivial. Manifolds which aren't stably parallelizable are plentiful, and they can all be embedded into $\mathbb{R}^n$ or $S^n$ for sufficiently large $n$, so that gives a large source of examples.
The interesting question, I guess, is how low the dimension of $X$ can be in this construction. If we require $X$ to be closed and orientable then $\dim X \ge 4$. This is because for $\dim X \le 3$ any such manifold is in fact stably parallelizable (which implies that the oriented bordism groups $MSO_1, MSO_2, MSO_3$ all vanish). When $\dim X = 4$ we can take $X$ to be any closed orientable $4$-manifold with nonzero signature, since that implies that $p_1 \neq 0$. Arguably the simplest example of such a manifold is $\mathbb{CP}^2$ (which generates $MSO_4 \cong \mathbb{Z}$), which embeds into $\mathbb{R}^8$ or $S^8$ by Whitney.
Edit #2: In the above construction, if we don't require $X$ to be orientable then $X$ can be chosen to be any non-orientable manifold (since then $w_1$ won't vanish, so $X$ cannot be stably parallelizable). An example of minimal dimension is $X = \mathbb{RP}^2$, which embeds into $\mathbb{R}^4$ or $S^4$ by Whitney.
Edit: I don't know much about the case of not-necessarily-closed manifolds, but if you want to allow the target of the embedding to vary, so an embedding $X \to Y$ of a closed orientable manifold into another closed orientable manifold, then the comments above show that the normal bundle is stably trivial if $\dim Y \le 3$. In fact the normal bundle must be trivial: if $\dim X = 1$ then a vector bundle on $X$ is trivial iff it is stably trivial iff $w_1$ vanishes, and if $\dim Y = 3$ and $\dim X = 2$ then a line bundle on $X$ is trivial iff it is stably trivial iff $w_1$ vanishes.
So the minimum possible dimension of $X$ is $2$ and the minimum possible dimension of $Y$ is $4$ (again assuming that both $X$ and $Y$ are closed and orientable). This minimum is achievable: take $X$ to have nontrivial tangent bundle and take the embedding to be the diagonal embedding $X \to X \times X$. The normal bundle is just the tangent bundle again, so it is also nontrivial. In particular we can take $X$ to be a closed orientable surface with nonzero Euler characteristic, say $S^2$ (since then the Euler class does not vanish).
Comment: If the OP cares about non-orientable closed things, the smallest example of an embedding of closed manifolds $Y \to X$ for which $Y$ has nontrivial normal bundle is $\Bbb{RP}^1 \hookrightarrow \Bbb{RP}^2$ (consider the homeomorphism type of a tubular neighborhood); the smallest example for which $X$ is orientable but $Y$ needn't be is $\Bbb{RP}^2 \hookrightarrow \Bbb{RP}^3$ (consider the Stiefel-Whitney classes).
Answer: If you consider the the manifold $X=\mathbb P^2(\mathbb R)$ with coordinates $x:y:z$, its submanifold $Y$ given by $z=0$ is isomorphic to $X=\mathbb P^1(\mathbb R)$ and the normal bundle $N(Y/X)$ corresponds in that isomorphism to the non-trivial  tautological line bundle $\xi$ of $\mathbb P^1(\mathbb R)$.
Thus the normal bundle $N(Y/X)$ is non-trivial.

normal bundle on a submanifold


How do I investigate the effect of height of the fall of a marble on the size of a crater in sand?

Question: What do I need?
What would the most effective method be to reduce the uncertainty of my outcome?
Should I record the mass and diameter of the marble too or just the height?
If I change mass will it be more effective than height change?
Comment: Exactly what do you mean by the "size" of the crater? Is it how deep it is? How wide it is?
Comment: If I recall correctly, NASA has done experiments on crater size vs. high velocity impact speed.
Comment: I don't know what constraints your experiment has or what kinds of conditions it will be done under, but I recommend you compare your results to my favorite approximation in physics! Check out [this answer](https://physics.stackexchange.com/questions/146010/platform-diving-how-deep-does-one-go-into-the-water/146013#146013) and [this answer](https://physics.stackexchange.com/questions/167077/freefall-into-snow/167090#167090) for details on the approximation. Check out the other answers on the first post in particular, where a much more detailed analysis gave similar answers.
Answer:
How do I investigate the affect of height of the fall of a marble on
the size of a crater in sand?

It really depends on what you mean by the "size" of the crater. Are you talking about how deep it is? How wide it is?. Also, toy marbles come in a variety of sizes and are made of a variety of materials.
If you want to maximize the depth of the crater, then for a given mass and height of the fall you would want the marble with the smallest diameter, i.e., the marble of the greatest density. This will maximize the impact force per unit area of sand.
On the other hand, if you want to maximize the width of the crater, then for a given mass and height of the fall you would want a marble with a larger diameter in order to maximize the diameter of the crater.
Regarding mass vs height, the kinetic energy of the marble upon impact with the sand will be $mgh$. The greater the kinetic energy the greater the size of the impact, all other things being equal.  So if you double the mass you can halve the height to get essentially the same size impact, and vice-versa.
You can approximate the depth of the impact by equating the kinetic energy upon impact with the work done by the sand to bring the marble to a stop. Or
$$mgh=F_{ave}d$$
Where $F_{ave}$ is the average impact force and $d$ is the depth of the crater, ignoring the loss of gravitational potential energy over the distance $d$. The combination of $F_{ave}$ and $d$ will depend on the "hardness" of the sand. The harder the sand, the less the depth of the impact and the greater the average impact force, and vice-versa the softer the sand.
Hope this helps.


Blender 2.8+ set pass index for object?

Question: I am aware that in the Data API region I can locate the objects and set their object pass index but it is a fairly tedious exercise. Is there an easier way?
Answer: You can find it in the Properties Editor, in the Object tab:

You might also find it useful to use a very simple Python script to set different object indices for multiple objects(all selected in this case) at once:
<code>import bpy

some_starting_number = 15

for i,o in enumerate(bpy.context.selected_objects):
    o.pass_index = i + some_starting_number
</code>
(You would copy this into a new text block in the Text Editor and hit Run Script with some objects selected)

Blender 2.8+ set pass index for object?


Reasons for constraining single-ended Op-Amp VCC when multiple power rails available

Question: If I am utilising an op-amp, say a LM321/LM324, say in single-supply operation as a buffer and have a multiple suitable power rails available then are there, assuming I do not expect to utilise the full output swing of the opamp for any of my rails and none of the rails exceed the maximum specification, any potential advantages to using a lower-voltage supply rail?
Comment: Marginal reduction in power consumption.
Answer: If you have several choices on your VDD supply for the opamp, here are some thoughts:
1) use the cleanest VDD, and plan ahead to sustain the cleanliness. This minimizes the use of area/cost required for "local battery" R+C low-pass-filters on the opamp's VDD. The reasoning for the is the horrid PSRR of opamps at high frequencies.
2) using an LDO output (if clean enough) instead of a higher-voltage switchreg with its spikes and ringing
3) use the same VDD as your ADC, to avoid use of protective clamps between opamps and ADC
4) if  you have a huge amount of gain, as in magnetic-field-detection for robot-location, then using separate VDDs for the first few stages versus the final stages, is a way to reduce the likelihood of oscillation by sharing a common VDD.
5) identify the best-regulated VDD, and use that, if the DC_STABILITY is crucial
Answer:
any potential advantages to using a lower-voltage supply rail?

Yes, several. The LM324 for example can take as much as 32 V. But if the output goes to a device powered from eg. 3.3 V then powering the op amp from a similar voltage could:-

Prevent injection of current into the power supply of the receiving device (through its input protection diodes etc.), stopping it from malfunctioning or being damaged.
Greatly reduce power consumption in the op amp, reducing temperature drift and improving reliability.

The LM324 draws a maximum quiescent current of 1.2 mA at 5 V = 6 mW, but 3 mA at 30 V which equates to 90 mW. That might not sound like much, but with a thermal resistance of 88 °C/W it would cause nearly 8 °C of temperature rise. In a sensitive circuit the op amp could take several minutes to stabilize at the higher voltage. If the device needs to operate at high temperature that 8 °C could push it over the limit.
But that's not all. When the load draws significant current the power dissipation can be much higher. For example driving a 150 Ω load to 3 V (drawing 20 mA, the guaranteed minimum output source current) would only dissipate 40 mW with a 5 V supply, but a massive 540 mW with a 30 V supply.

The lower voltage stress could improve reliability and reduce sensitivity to power supply spikes and stray currents due to surface contamination of the chip and PCB.
If the lower voltage is supplied through a regulator (or secondary regulator if the primary power source is also regulated) it could be more stable and make the op amp's power supply rejection ratio less critical.
Lower output voltage swing could reduce EMI caused by a strong signal that produces higher output than needed. A 3.5V square wave is much 'quieter' than a 30 V square wave!
Comment: Hi, I went with this answer because I think it answered the question most directly and impacted my design, supported by good explanation. Thank you.
Answer: One main reason: interfacing your op-amp to other single-ended electronics like an ADC or a logic circuit (e.g., a comparator.) This ensures the output swing of the amp doesn't exceed the input range of the downstream device.
Likewise, if the upstream circuit is single ended, referring the op-amp to a midpoint reference (virtual ground) makes things easier sometimes.
Comment: Go on, ... explain why!
Comment: Because this reduces the chance of voltage overshoot and damage?


3 Factor HJM model, do these factors have an economic meaning?

Question: In the HJM model, in case we have 3 factors, do these factors have an economic meaning at all ?
Answer: One of the motivations for multifactor models such as Two-Factor-HW, HJM and LMM (Lobor-Market-Model) is derived from the properties of the yield curve.
One can run a  Principal-Component-Analysis on yield-curve data in order to analyse the number of independant factors contributing to yield curve movements.
It has been shown that there are generally three types of movements a yield curve can undergo (and thus also three factors driving it's movements):

rougly flat (parallel shift → average rate)
upward or downward sloping (tilt → slope )
hump shaped (flex →curvature)

One factor models such as Hull-White can only capture parallel shifts of the yield curve. Two factor models can either reproduce the tilt or the hump. With a three factor model all three common yield curve patterns can be modelled.
Fixed Income Markets and Their Derivatives (See p. 136 ) mentions/explains that the first two componetns of a PCA explain up to 95-98% of the variations of the yield curve. The remaining variation is mostly picked up by the fird factor. (I will also refer you to Interest Rate Risk Modeling: The Fixed Income Valuation Course as an alternative source)
Comment: Thanks for sharing this info. This is however too abstract for me, I understand PCA decerns 3 indep modes of changes of the yield curve (info contribution should be linked to variance I suppose) but I cannot link the shift/tilt/curvature of a yeild curve to the actual HJM model formulation ( my understanding is that 3 factos <=> 3 volatility term structures ), a simple example would help ( in a layman's point of view ) if you have any.
Comment: okey so you would like to see how the HJM is actually able to produce those shapes with it's three factors correct? Thus how the mechanics translate into the actual yield curve form ?
Comment: Well, I would like to understand the logic behind the choice of these factors, and if this translates into capturing information yield curve then yes I would be happy to have a "mecanical" example or something that could help me understand , thanks :)
Comment: First you would like to know/understand why you would use three factors instead of two or one - what are the indicators for such a descicion ? Second you would like to see how this factors are actually chosen - thus what correlation do we assume and which forward rates do we chose to propage correct ?
Comment: Yes that'd be great.


Upload a video using asp.net MVC WebService

Question: I want to upload a video file using asp.net mvc . I am sending the file as postbody. How can this be retrieved later from the server using webservice. I have seen this example . Also this question helped me to understand it more. But I m not sure how to fetch post body.
  But no sure how this works. How to do his properly in .net c#
Answer: In order for the file to be available later, you need to save it somewhere during the upload - either to a database or a folder on the server.  Then, your web service needs to know how to retrieve it from that location.


If high interest rates cause strong currencies what do Argentina and Zimbabwe have currency collapse?

Question: These two countries like Argentina have massive interest rate, over 50%, yet nobody can claim the argentinian peso is stronger. In fact its like 1000 to the dollar and was much stronger before. So do high interest rates really strengthen a currency , or in fact from real evidence, weaken it?
Answer: Interest rate does strengthen currency. There is both theoretical and also empirical evidence for it (eg see Copeland Exchange Rates  and International Finance).
However, interest rate is far from the only variable that determines exchange rate. Even in a simple monetary model of exchange rates, the exchange rate is given by;
$$\ln S= \ln(m)- \ln(m_f) -(\ln(y)-\ln(y_f))+\lambda(i-i_f)$$
where $m$ is money supply at home and $m_f$ in foreign country, $y$ is the real output at home and $y_f$ in foreign country and $i$ is the interest rate at home and $i_f$ in foreign country (also note higher S means weaker currency).
As you can clearly see there is bunch of other variables that determine exchange rate. For example, if your economy is doing badly (drop in real output y), exchange rate will depreciate despite of high interest rates. Similarly, if country expands its money supply $m$ a lot exchange rate will depreciate even if interest rates are high. Moreover, exchange rates are always relative. Even if your country's economy is doing well, exchange rate might depreciate if other economies are doing even better. Furthermore, there are also some other variables that can explain differences in exchange rates, not mentioned in the simple model above, like people's expectations.
In short, the problem is that your observation is unconditional. Your question is tantamount to asking, I see this obese person exercising twice a day but they are also very obese so does exercise cause obesity? Clearly persons weight, similarly to exchange rate is caused by multitude of factors. Exercise can, ceteris paribus lower your weight, but if you will eat 20 McDonald hamburgers a day you will still gain weight and become obese despite exercise.
Virtually every scientific explanation is conditional. For example, postulate in physics that objects in vacuum will fall to ground at the same speed is conditional on not adding energy to second object by shooting laser at a mirror on its back or attaching rocket engine on it.


Renaming site, moving domain after 3 yrs. Should I reconsider?

Question: After recently announcing it, one of my readers with a background in website management sent me an email saying that I should reconsider moving my domain from [keyword]news.org to [same keyword]lab.com.
It is a content-heavy news site around products that I hope to eventually build into a more comprehensive authority for the [keyword] industry I'm covering w/ B2B services, merchandise, etc. The current domain is a bit generic & I think the new one will be more marketable.
Relevant stats:

320k-350k pv's/month
Google brings in 39% and Yahoo/Bing
4% of traffic
10-11% of monthly search strings
contains " news"

SEOMoz Open Site Explorer stats:

Page authority: 65/100
Domain authority: 58/100
Linking root domains: 226
Total links: 35,700

I am familiar with what I need to do as far as 301 redirects, etc. I was assuming that I'd be ok after following Google's recommended procedures but now I am not so sure.
Comment: Those stats from SEOmoz's tool are speculative and shouldn't be used to make important decisions.
Comment: Is there a better tool? Maybe Google Webmaster Tools...been a while since I poked around in there.
Answer: Two Points:

Exact match keyworded domains, while powerful now, will be less-so in the future. Google's web-spam team has already indicated this.
If it ain't broke - don't fix it. Really, it's the content that will win moving forward, not the domain name (unless the domain is unique like Twitter/Google/Yahoo/Techchrunch/etc).
Answer: Mike Hudson has all very good points. Another point is that Google newer domains as more likely to be spam so there is a chance you will lose some of your Page Authority with Google for a while because they are unsure if they can trust you.


Navigating on the internet sometimes I get this webpage "mackeeperapp2"

Question: Is mackeeperapp2 a safe website? Does that mean I have some security problems? I am in possession of a Mac OS X v.10.9.4, which actually is not mine at all, and I wouldn't like to risk or imperil it. As you can notice, I have not so much experience with Mac OS X.
Answer: These are pop-up ads, usually opened in new tabs or windows, by aggressive sites that are paid by the makers of MacKeeper to advertise for them. The appearance of these advertisements has nothing to do with the state of your Mac -- your computer is good, safe and fine.
The MacKeeper application itself is not well regarded:

MacKeeper has been described by various sources as highly invasive malware that can de-stablize your operating system, adding that it is unethically marketed, with a history of making false advertising claims, by a company called Zeobit, and a rip-off.


Should Catholics in a state of grace call themselves sinners?

Question: The Bible says our righteousness is a filthy rag(works) it also says we are the righteous of God in Christ Jesus. As a Catholic at a state of grace is it right to still call myself a sinner when I have been justified by grace taking upon me Jesus Christ righteous?
Comment: Your question seems to imply that you have become sinless.
Answer: Being in a state of grace is defined as:

Condition of a person who is free from mortal sin and pleasing to God. It is the state of being in God's friendship and the necessary condition of the soul at death in order to attain heaven.

However, the Catechism makes a distinction between sins as mortal or venial so it is possible to be in a state of grace (free from mortal sin) while still being a sinner (having committed venial sins). Indeed, the Catechism refers to one who has committed venial sin(s) but not mortal sins as a "sinner" despite being in a state of grace (emphasis added):

1863 Venial sin weakens charity; it manifests a disordered affection for created goods; it impedes the soul's progress in the exercise of the virtues and the practice of the moral good; it merits temporal punishment. Deliberate and unrepented venial sin disposes us little by little to commit mortal sin. However venial sin does not set us in direct opposition to the will and friendship of God; it does not break the covenant with God. With God's grace it is humanly reparable. "Venial sin does not deprive the sinner of sanctifying grace, friendship with God, charity, and consequently eternal happiness."

One could perhaps claim to be not a sinner just after having received absolution (so that you are free from mortal and venial sin), but even so the Catechism uses the word "sinner" to refer to a person who has just received absolution (emphasis added):

Satisfaction
1459 Many sins wrong our neighbor. One must do what is possible in order to repair the harm (e.g., return stolen goods, restore the reputation of someone slandered, pay compensation for injuries). Simple justice requires as much. But sin also injures and weakens the sinner himself, as well as his relationships with God and neighbor. Absolution takes away sin, but it does not remedy all the disorders sin has caused. Raised up from sin, the sinner must still recover his full spiritual health by doing something more to make amends for the sin: he must "make satisfaction for" or "expiate" his sins. This satisfaction is also called "penance."

The Catechism could easily refer to the "sinner" who "must still recover his full spiritual health" as, for example, a "penitent", yet it nonetheless continues to refer to the person as a "sinner".
Therefore, I would still call myself a sinner even if I'm in a state of grace. Even if one has recently received absolution from confession, in honesty and humility it is probably not long before one commits another venial sin and can no longer claim to be free of all sin.
Answer: Should Catholics in a state of grace call themselves sinners?
The short answer is yes.
Being in the state of grace does not mean we are not sinners, but that we still share in the presence of God within their souls while being yet sinners!
The state of grace does not mean that we are without sin or without any guilt due to former personal sins committed against one of the ten commandments given to Moses on Mount Sinai.
Although we may be in the state of grace, we are nevertheless not sinless like the Virgin Mary though a divine privilege which God accorded to her alone.
It warms the heart, to say the rosary in French, because they add the words, poor sinners in their Ave Maria.

Je vous salue, Marie pleine de grâces;
  le Seigneur est avec vous.
  Vous êtes bénie entre toutes les femmes
  Et Jésus, le fruit de vos entrailles, est béni.
  Sainte Marie, Mère de Dieu,
  priez pour nous pauvres pécheurs,
  maintenant et à l'heure de notre mort.
  Amen.

Please do not forget the words of St. John the Apostle:

If we say that we have no sin, we deceive ourselves, and the truth is not in us. - 1 John 1:8
Comment: +1 for citing 1 John 1:8.
Answer: It's perfectly fine to call yourself a sinner, as in a fallen human being prone to sin, or having sinned in the past, even if forgiven. It's a statement of humility, and with such there is nothing wrong—its even virtuous in certain cases. However, it can become a "cloak for malice." We should live, says, St. Peter:

1 Peter 2:16 (DRB) As free, and not as making liberty a cloak for malice, but as the servants of God.

Just because we have been forgiven, and recieved grace, and escaped the wrath of God, it gives us absolutely no right to sin in the future. For:

Sirach 5:5-9 (DRB)  Be not without fear about sin forgiven, and add not sin upon sin: 6 And say not: The mercy of the Lord is great, he will have mercy on the multitude of my sins. 7 For mercy and wrath quickly come from him, and his wrath looketh upon sinners. 8 Delay not to be converted to the Lord, and defer it not from day to day. 9 For his wrath shall come on a sudden, and in the time of vengeance he will destroy thee.

TL;DR Inasmuch as it is right to call someone who has sinned a sinner, it is perfectly fine to call oneself—or even in certain contexts, another—a sinner. Inasmuch as the sins forgiven one who is justified are no longer existent, but blotted out, it would be wrong to call oneself 'sinful' or 'in a state of sin,' because this would be false, and an affront to the grace of Christ, which 'remembers your sins no more' (Hebrews 8:12).
Comment: [x] Catholic Bible, [x] Catholic Book in the Bible,  [ ] Catholic Catechism, [ ] Catholic Saints.   I'm not sure one wouldn't interpret this as self-interpretation of the Bible. I'd bet St. Theresa of Avila wrote _something_ about this.  I'm not going to flag as Not An Answer, but I do want to encourage people answering questions on the [tag:Catholicism] tag to plumb the deposit of faith.
Comment: The Catholic Church approves, as far as I know, not only the "Hail Mary", which contains "pray for us sinners", but also the "Memorare" whose standard English translation contains "before thee I stand, sinful and sorrowful". (The Latin version, however, has "gemens peccator".)
Comment: @PeterTurner Here is [my take](https://christianity.meta.stackexchange.com/a/6692/8617) on that issue.
Answer: Yes, because they sin if say they are without sin.
Council of Trent session 6 on Justification, Chapter IX. "Against the vain confidence of heretics" (Denzinger 802):

But, although it is necessary to believe that sins neither are remitted, nor ever were remitted save gratuitously by the mercy of God for Christ's sake; yet is it not to be said, that sins are forgiven, or have been forgiven, to any one who boasts of his confidence and certainty of the remission of his sins, and rests on that alone; seeing that it may exist, yea does in our day exist, amongst heretics and schismatics; and with great vehemence is this vain confidence, and one alien from all godliness, preached up in opposition to the Catholic Church. But neither is this to be asserted—that they who are truly justified must needs, without any doubting whatever, settle within themselves that they are justified, and that no one is absolved from sins and justified, but he that believes for certain that he is absolved and justified; and that absolution and justification are effected by this faith alone: as though whoso has not this belief, doubts of the promises of God, and of the efficacy of the death and resurrection of Christ. For even as no pious person ought to doubt of the mercy of God, of the merit of Christ, and of the virtue and efficacy of the sacraments, even so each one, when he regards himself, and his own weakness and indisposition, may have fear and apprehension touching his own grace; seeing that no one can know with a certainty of faith, which can not be subject to error, that he has obtained the grace of God.

Trent also defined these de fide dogmas:

CANON XIII.—If any one saith, that it is necessary for every one, for the obtaining the remission of sins, that he believe for certain, and without any wavering arising from his own infirmity and indisposition, that his sins are forgiven him: let him be anathema.

CANON XVI.—If any one saith, that he will for certain, of an absolute and infallible certainty, have that great gift of perseverance unto the end,—unless he have learned this by special revelation: let him be anathema.


How to visualize surface normals as Marker::Arrow for each point in rviz?

Question:
Hi,
I would like to show the surface normals of a point cloud in rviz. Below is what I was trying:

Create a MarkerArray and corresponding publisher
Resize the MarkerArray with the size of the point cloud to be visualized (25344 points in this case) at the very first
Assign frame_id, ns, id, type, action, color for each marker just once
update position of the arrows with the point cloud at each iteration
update markers scales with the point cloud normal data at each iteration
publish the markerarray

Whenever it publishes the markerarray, RAM blows up and swap is heavily used and PC stalls there.
What do you think I am doing very badly wrong here? Or isn't it possible to visualize that many arrows (25344 of them) in the rviz? If so, should I use other tools coming with PCL?
Thanks a lot...
-Kadir-

Originally posted by Kadir Firat Uyanik on ROS Answers with karma: 288 on 2011-02-16
Post score: 1

Original comments
Comment by dejanpan on 2011-02-17:
Hi Kadir,
we did it with MarkerArray message but it also choked up rviz a bit. You can have a look at our code here: http://code.cs.tum.edu/indefero/index.php//p/mapping/source/tree/master/pcl_cloud_tools/src/pcl_normal_visualization.cpp
D.
Comment by chinmay_sujir on 2023-01-11:
The above link doesn't work. Any chance you still have this somewhere?
Answer:
It is very likely that rviz chokes up because of the amount of markers. I think each arrow is a separate 3D object. I would recommend using the pcl visualization tool:
http://www.ros.org/wiki/pcl_visualization
You can use the existing PointNormal data type, defined here:
http://www.ros.org/doc/api/pcl/html/point__types_8h_source.html
Since you already have the algorithm to calculate the normals, all you have to do is build a pcl cloud and fill out the fields. Here's the nice part about using pcl - you can set how many normals you want to display - for example, one every 10 or 20 points. This should make it much quicker.

Originally posted by Ivan Dryanovski with karma: 4954 on 2011-02-16
This answer was NOT ACCEPTED on the original site
Post score: 1


Is this question insufficient after edit?

Question: So I asked the question "Can one construct a non-zero (conditional) probability in this situation?", which was downvoted and voted to close without the last edits (so I deleted it - The original tag was quantum information). Is it welcome to this stack exchange after the edit?
Comment: I removed the text of the question, there is no need to reproduce it here. I'm confused though, I don't see that the question was deleted in the question's history
Comment: Note to readers - asking this sort of question is one of the fundamental purposes of meta! This sort of question is on topic
Comment: @gls because it was asked as a seperate question
Answer: First of all, there is no reason to delete a question and then ask it again with only minor changes, you can just edit the original question.
Regarding the question itself, I do agree with the voters that it's not very clear what is been asked. I don't know that it should be closed by it's borderline there. The wording is in general vague and unspecific. For example, you say

What one "sees" is an eigenvalue linked to that of a photon.

which might be interpreted in different ways. What photon are you talking about? What do you mean by "see" here? Where did eigenvalues come from in this discussion?
Or

With each eigenvalue one can determine there is some "source"

what is a "source"? Where did you get this statement from? etc.
There might be some merit in the question you maybe meant to ask, but it's not easy to get to it.
In general, I would try to avoid using concepts that you cannot properly define and try to formulate things mathematically as well as in words, when possible. Finally, a good rule of thumb is that if you cannot give a very good idea of the question being asked in the title of the question itself, that is a good indication that it's not going to be a good question. There are exceptions, but it usually works pretty well (and note that from the title of your question, I would have no idea what is actually being asked).
Comment: @MoreAnonymous you keep reiterating that those points are clear, so I'm not sure what else to say here. I'm sure they look clear enough to you, but clearly others don't see it the same way, so you just need to make a bigger effort into making questions as clear and focused as possible. This is not easy, but it's the only way to make questions useful to some other than you (and to yourself, because the process of pinning down what exactly the misunderstanding is usually goes a long way towards solving a problem)
Comment: @MoreAnonymous If multiple people tell you that it's not clear what you are asking, it means that you should change the way you ask questions, period, there isn't much to argue there. I understand that asking good questions is not easy, especially when you don't have a very clear idea of what you are talking about. Still, you should try to break apart your question(s) into more specific and focused ones, that are easier to understand and answer, and will probably also be more useful to other people
Comment: I do mention source as "the word source seems to imply it's spatially confined and uniqueness of hamiltonian producing these photons" the statement source came from the youtube video (I think). Also, I do have a vague/incomplete mathematical idea of what I'm talking about see: https://quantumcomputing.stackexchange.com/a/8624/5045
Comment: Again I use the word "sees"  as opposed to "measures" in reference to the video.
Comment: Oh I never argued that they were "clear." I was merely unaware that your criticism didn't take my defence into account. I see so I have to put more effort? Would including my (incomplete/vague) answer part of that help in this cause as well or work against me?
Comment: simply put, "*the word source seems to imply it's spatially confined and uniqueness of hamiltonian producing these photons*" does not clarify things, not enough at least. Also, you cannot expect people to watch a video to understand the question. I would suggest you to break down these questions into their "elementary components", to figure out exactly where a problem is. Again, a good rule of thumb is that the core of the question should fit in the few words of a title.


Baire sets of $X$ possess the required Cartesian product property

Question: Let $X=X_{1}\times X_{2}$ is locally compact space, and define $$E=\{E_{1}\times E_{2}\;|\; E_{i}\; \text{is a Borel set in}\; X_{i}\; ,\; \text{for}\; i=1,2\}$$ Now why the Baire sets of $X$ are in the $\sigma$-algebra generated by $E$? Of course that every Baire set is Borel too so all Baires of $X_{i}$ is a Borel of it too.
Comment: [Asked and answered on MO](http://mathoverflow.net/questions/117930/).
Comment: I deleted a straightforward answer based on the Stone-Weierstrass theorem because apparently AmirHosein doesn't assume the Hausdorff condition. Please specify what you mean by local compactness: a compact neighborhood for every point? a base of compact neighborhoods for every point? a base of closed compact neighborhoods for every point? What is your definition of the Baire $\sigma$-algebra? The one generated by the zero sets of continuous functions or the one generated by (closed?) compact $G_\delta$-sets?
Answer: (To kick it from the unanswered queue)
Original MO link: Baire sets of $X$
possess the required Cartesian product property (as mentioned in the comment)
@JosephVanName's solution:

The idea of the proof is to make use of compactness to show that sets of the form $f^{-1}(0)^{c}$ are countable unions of boxes in $E$.
For a proof, assume that $f:X^{2}\rightarrow[0,1]$ is a continuous function with compact support. Let $U=f^{-1}(0,1]$. Then since $f$ has compact support, the sets $f^{-1}[a,1]$ are compact for $a>0$, so the set $U$ is Lindelof. If $x\in U$, then by the definition of the product topology there are open sets $A_{1}\subseteq X_{1},A_{2}\subseteq X_{2}$ with $x\in A_{1}\times A_{2}\subseteq U$. If we set $A_{x}=A_{1}\times A_{2}$, then $A_{x}\in E$. Furthermore, by the Lindelof property, there is some $\{x_{n}|n\in\mathbb{N}\}\subseteq U$ with $U=\bigcup_{n}A_{x_{n}}$. Therefore, we have $U$ be in the $\sigma$-algebra generated by $E$ as well. Therefore since each the $\sigma$-algebra generated by $E$ contains each cozero set of compact support, the $\sigma$-algebra generated by $E$ contains each Baire set.


When did they start requiring holotypes for species description?

Question: I know they weren't required in the early 1800s but obviously they are now so just wondering when this started being required and/or who coined holotype. Internet research yielded no good answers.
Comment: Presumably botany and zoology receive slightly different answers. I would assume the foundation dates of the bodies that publish the ICN and ICZN are possible answers.  As I understand it, use of type specimens was widely practiced and recommended from even before Linaeus; maybe in the 19th century there was a desire to codify the practice. It's not clear if you are asking when codification started or when the practice itself started.
Comment: According to https://www.iapt-taxon.org/historic/index.htm , the first edition of the ICN dates to 1867.  See also https://en.wikipedia.org/wiki/International_Botanical_Congress , which says this was at the 4th meeting of the IBC, in Paris in 1867.
Comment: either is fine, i'm just trying to get a better understanding of whether i can expect there to be a type specimen based on the year of publication
Answer: As far as botany is concerned, the concept of type specimen and obligation of using one was introduced in the 1935 version of the code (the so-called Cambridge Rules).
For zoology, surprisingly, it is only compulsory to explicitely name a name-bearing specimen since 1999, when the 4th (and current) edition of the ICZN code was published.
The term 'holotype' though (and the concept of typification) is older. The earliest occurrence I can find is in this short communication in the journal Science from 1897: What is a type in Natural History? by Charles Schuchert.


How to visualize local complete intersection morphisms?

Question: As the question title asks for, how do others visualize local complete intersection morphisms? My experiment in asking people in real life didn't pan out, so I'm consulting the MO algebraic geometry community. Bonus points for pictures!
Comment: A morphism is lci iff it factors as a regular embedding and a smooth morphism. You can visualize a regular embedding as a subscheme which admits a tubular neighborhood, and a smooth morphism as one which is locally a projection with smooth fibers. Then you can think of lci as precisely the condition that the morphism has a well behaved normal bundle.
Comment: Hmm, of all the classes of morphisms out there, I find this one of the most intuitive... The definition is entirely geometric!
Answer: As Dan Petersen said the comments, an lci morphism $f:X\to Y$ is precisely one that factors Zariski-locally as $X\to Y\times \mathbf{A}^n \to Y$, where $X\to Y\times \mathbf{A}^n$ is a regular embedding (on affines, this means that you are looking at a closed subscheme defining by the vanishing of an ideal generated by a regular sequence) and $Y\times \mathbf{A}^n \to Y$ is the projection map. A regular embedding should be thought of as a closed subscheme which has a tubular neighborhood (every closed immersion of smooth schemes is a regular embedding), so an lci morphism is precisely a morphism for which it is reasonable to talk about the normal bundle.
This can be made more precise. Namely, an lci morphism $f:X\to Y$ can be characterized as a morphism such that the relative cotangent complex $L_{Y/X}$ is perfect, and has Tor-amplitude in $[-1,0]$. The latter statement means that for every quasicoherent sheaf $\mathscr{F}$ on $Y$, the derived tensor product $L_{Y/X}\otimes^\mathbf{L} \mathscr{F}$ has cohomology concentrated in degrees $-1$ and $0$. (If your definition of an lci morphism is as a morphism which is locally given by quotienting by a regular sequence, then one direction of the above statement is proved as Tag 08SL.) In any case, the conormal bundle $N_{Y/X}$ can now be defined as $L_{Y/X}[-1]$, so that the normal bundle of $f$ is $N_{Y/X}^\vee = L_{Y/X}^\vee [-1]$. Since $f$ is an lci morphism, this is actually a vector bundle over $Y$, so it makes sense to call this the normal bundle. This should make sense: if $f:Y = \mathrm{Spec}(B) \to X = \mathrm{Spec}(A)$ is a surjective morphism and $I = \ker(A\to B)$, then $H^1(L_{Y/X}) = I/I^2$.
Comment: An lci morphism is precisely a morphism for which it is reasonable to talk about the *virtual tangent bundle*. It will have a normal bundle if it is an lci closed immersion (AKA regular closed immersion). If it is not a closed immersion it may still have smoething in degree 0 and will just be some 2 term complex.
Comment: Also Im not sure about your Zariski local factorization, youll also have some etale map in there in general (regular embedding followed by etale followed by affine space projection)