Can I paint a deck when wet weather is forecasted?

Question: I am planning on painting my mothers deck and I have a limited amount of time.  I am planning on painting it on Saturday, but I saw there is forecast for rain.  I am wondering if it would be better to paint before or after the rain.  I could possibly paint it on Friday or Monday, but with the sanding and priming I have to do, I can't really do much earlier and my mom comes back on Tuesday.  I'm planning on power washing too, probably Wednesday morning because it's supposed to be pretty warm that day, so it would dry well.
Answer: I would paint after the rain and make sure there is a tarp over the deck before it rains.  You need the manufacturer's guidelines but two simple rules to painting outside is not touching a damp surface - and it can take a few days for a deck to dry out and not painting within 48 hours of rain forecast.  At 24 hours after painting you could tarp the deck but really better to have a few clear days.  If rain is constant then you just need to wait.
Answer: wheather has great influence on painting, if you have to paint on a rainy day, then you must keep your room dry to protect the painting.


Why do sites like Amazon not show Buy Now or Add to Cart buttons in product listings?

Question: I have observed recently that sites like Amazon have made some changes and the Add to Cart button now appears only when the user clicks on the thumbnail and goes to the detailed product page. Does anybody know why?
Answer: Most likely because product options/variations cannot be selected from the product thumbnail itself. Defaulting variations in color, size and quantity when a user clicks "adds to cart" from a product thumbnail page could really be a UX/Customer care nightmare if the user is not aware or notified product variations exist or that they can be modified. Leading to the wrong product being shipped to the customer. (Example: Customer thought they ordered a 16oz coffee cup but instead received a 10oz coffee cup)
In the long run, having the "add to cart" button on a product thumbnail ultimately can create more frustration than convenience for the user because the variations and product details are hidden. The user should have the necessary details visible to make an informed purchase. This helps both the user and Amazon with returns and incorrect/mistaken orders.
Answer: Purpose of Recommendation
Get the attention from user by using a thumbnail image and attractive price.
Other details like specifications, features, add to cart, same day availability, product variations, color selection cannot be displayed directly.
Not showing add to cart, enables customers to go through the product by navigating and add them to cart


Headphone is not working

Question: I am running ubuntu 10.10 on a Lenovo ideapad z560. The speakers run fine but the headphones are not recognized when i plug them in. Audio comes out of the speakers only. I tried all alsa and pulseaudio settings but to no avail. I came to know that this is a known bug and many people are having this problem. I was wondering whether shifting to OSS4 would help. I need some advice because once i make the switch i would need to reconfigure a large number of audio apps. Thanks in advance
Answer: I would advise that you leave your sound servers alone, maybe you should try if a USB based headphone will help work around the problem until the bug is fixed, also make sure that it is really not a hardware issue, I had an old Dell Inspiron that had a similar problem and it turned out that the problem was hardware failure, Windows that came on it with the proper drivers had the same problem.
Answer: Have you tried to explicitly set the sound card's model in the alsa-base.conf file?

Re: headphone jack not recognised by ubuntu 10.10
HdaIntelSoundHowto
Comment: The hdaintelsoundhowto solved my problem. Thanks a lot for the fix.
Comment: Iam trying out the linuxant drivers. hope this works.

Headphone is not working


the five precepts and marijuana - does marijuana count as an intoxicant?

Question: The fifth of the precepts is "I undertake the training to refrain from intoxicants."
does smoking marijuana count as an intoxicant ?
Answer: Yes. Marijuana is an intoxicating substance.
From AccessToInsight.org's The Five Precepts: pañca-sila:

Suramerayamajja pamadatthana veramani sikkhapadam samadiyami
I undertake the precept to refrain from intoxicating drinks and drugs
which lead to carelessness.

It comes from the suttas e.g. AN 8.39.
The reason for abstaining from alcohol, drugs and any other intoxicating substances is explained below. It's because intoxicating substances cause heedlessness and moral recklessness, and results in one breaking the other four precepts, because a person's best judgment is impaired under the influence of intoxicating substances.
However, if intoxicating substances are consumed in a strictly controlled way as a medicine, administered by a medical professional, then it is ok. For e.g. I have heard that psilocybin has been used for treating severe depression.
From the essay "A Discipline of Sobriety" by Ven. Bodhi (the highlighted statements apply to both alcohol and drugs):

For his lay followers the Buddha has prescribed five precepts as the
minimal moral observance: abstinence from killing, stealing, sexual
misconduct, false speech, and the use of intoxicants. He did not lay
down these precepts arbitrarily or out of compliance with ancient
customs, but because he understood, with his omniscient knowledge,
which lines of conduct lead to our welfare and happiness and which
lead to harm and suffering. The fifth precept, it should be stressed,
is not a pledge merely to abstain from intoxication or from excessive
consumption of liquor. It calls for nothing short of total abstinence.
By this rule the Buddha shows that he has understood well the subtle,
pernicious nature of addiction. Alcoholism rarely claims its victims
in a sudden swoop. Usually it sets in gradually, beginning perhaps
with the social icebreaker, the drink among friends, or the cocktail
after a hard day's work. But it does not stop there: slowly it sinks
its talons into its victims' hearts until they are reduced to its
helpless prey.
To dispel any doubt about his reasons for prescribing this precept,
the Buddha has written the explanation into the rule itself: one is to
refrain from the use of intoxicating drinks and drugs because they are
the cause of heedlessness (pamada). Heedlessness means moral
recklessness, disregard for the bounds between right and wrong. It is
the loss of heedfulness (appamada), moral scrupulousness based on a
keen perception of the dangers in unwholesome states. Heedfulness is
the keynote of the Buddhist path, "the way to the Deathless," running
through all three stages of the path: morality, concentration, and
wisdom. To indulge in intoxicating drinks is to risk falling away from
each stage. The use of alcohol blunts the sense of shame and moral
dread and thus leads almost inevitably to a breach of the other
precepts. One addicted to liquor will have little hesitation to lie or
steal, will lose all sense of sexual decency, and may easily be
provoked even to murder. Hard statistics clearly confirm the close
connection between the use of alcohol and violent crime, not to speak
of traffic accidents, occupational hazards, and disharmony within the
home. Alcoholism is indeed a most costly burden on the whole society.
When the use of intoxicants eats away at even the most basic moral
scruples, little need be said about its corrosive influence on the two
higher stages of the path. A mind besotted by drink will lack the
alertness required for meditative training and certainly won't be able
to make the fine distinctions between good and bad mental qualities
needed to develop wisdom. The Buddhist path in its entirety is a
discipline of sobriety, a discipline which demands the courage and
honesty to take a long, hard, utterly sober look at the sobering
truths about existence. Such courage and honesty will hardly be
possible for one who must escape from truth into the glittering but
fragile fantasyland opened up by drink and drugs.
It may well be that a mature, reasonably well-adjusted person can
enjoy a few drinks with friends without turning into a drunkard or a
murderous fiend. But there is another factor to consider: namely, that
this life is not the only life we lead. Our stream of consciousness
does not terminate with death but continues on in other forms, and the
form it takes is determined by our habits, propensities, and actions
in this present life. The possibilities of rebirth are boundless, yet
the road to the lower realms is wide and smooth, the road upward steep
and narrow. If we were ordered to walk along a narrow ledge
overlooking a sharp precipice, we certainly would not want to put
ourselves at risk by first enjoying a few drinks. We would be too
keenly aware that nothing less than our life is at stake. If we only
had eyes to see, we would realize that this is a perfect metaphor for
the human condition, as the Buddha himself, the One with Vision,
confirms (see SN 56:42). As human beings we walk along a narrow ledge,
and if our moral sense is dulled we can easily topple over the edge,
down to the plane of misery, from which it is extremely difficult to
re-emerge.
But it is not for our own sakes alone, nor even for the wider benefit
of our family and friends, that we should heed the Buddha's injunction
to abstain from intoxicants. To do so is also part of our personal
responsibility for preserving the Buddha's Sasana. The Teaching can
survive only as long as its followers uphold it, and in the present
day one of the most insidious corruptions eating away at the entrails
of Buddhism is the extensive spread of the drinking habit among those
same followers. If we truly want the Dhamma to endure long, to keep
the path to deliverance open for all the world, then we must remain
heedful. If the current trend continues and more and more Buddhists
succumb to the lure of intoxicating drinks, we can be sure that the
Teaching will perish in all but name. At this very moment of history
when its message has become most urgent, the sacred Dhamma of the
Buddha will be irreparably lost, drowned out by the clinking of
glasses and our rounds of merry toasts.
Comment: @sorta_buddhist As I understand them, nicotine and caffeine do not cause heedlessness or moral recklessness, so the fifth precept does not apply to them.
Comment: what about nicotine? caffeine?
Comment: A glass of wine does not cause heedlessness and/or moral recklessness either. It might actually not lead to someone desiring two glasses, but strictly a single one (for instance with a dish that goes well with wine). It might not even be a glass, but a bourbon chocolate. It might be Listerine, which contains alcohol and is absorbed by our mouth tissue just as three or four droplets of vodka. It's also forbidden to eat ripe fruits, which often contain significant amounts of ethanol.
Comment: When I smoked marijuana it definitely impaired my judgement. Even walking up and down stairs became difficult. It made mindfulness impossible. Because of that experience I am inclined to agree for myself. yet I also acknowledge that for others in deep constant pain marijuana might provide relief. The precept assures balance.
Answer: Yes, if used recreationally it is obviously against the precept. It is distracting, makes one less serious, careless and indulgent.
There are also a lot of drawbacks as in withdrawal when quitting.
Nicotine and Caffeine are also intoxicants.
Comment: That's obviously not true. Both of these produce euphoric effects, caffeine can even be hallucinogenic. Taken together these are insanely addictive and will absolutely alter behavior and change brain chemistry. These will lead to heedlessness and are on the treshold of sensuality.
Comment: Nicotine and caffeine are addictive substances, but they are not intoxicating substances.
Answer: Yes, it is.

SurāMerayamajjaPamādatthānā VeramaniSikkhāpadam Samādiyāmi
I choose (undertake) to manage the basis of restrain-oneself-practice instead of the management of the craziness's basis and stupidness's basis, which causing unwholesome mindfulness ( forgotten the meditation object and losing the control of mind and actions which might cause breaking other precept easily).

When you are smoking marijuana, it's hard to thinking of the meditation object or any practice lesson.
If one still addict on some intoxicants, he can re-making attentions by reciting 5 precepts everyday after hanging because it reminds him what he should do. This is better than worrying and faking himself whether "I feel better when I forget 5 precepts, and I'm not ready to keep 5 precepts, so I will undertake/recite it next time when I'm ready." Because no one is ready at first. Everyone has been fail before. So don't care of "I am still smoking marijuana", just care of "re-recite 5 precepts everyday".  One day after that in many years, this one is going to be better.


When is guilt in depression considered psychotic?

Question: Guilt is a feature of Major clinical Depression. My doubt is, can guilt be considered delusional for making a diagnosis of mood-congruent psychotic depression? Can there be a delusional guilt?  Because, wouldn't a person with depression if guilty, be always firm in his belief (which is characteristic of a delusion)?
Comment: I don't understand your questions.
Comment: @CareyGregory I mean to ask, can guilt be considered delusional for making a diagnosis of mood-congruent psychotic depression?
Comment: This is an excellent question - I am eager to see if a psychologist/psychiatrist can offer insight into how it is diagnosed in practice.  The root question of how to define what constitutes a delusion is an issue that stands in the overlap between psychology and philosophy.   I imagine that your specific question's answer will involve the extent/degree of the belief, and the degree to which it creates disruption in the individual's life.
Comment: I asked my proff today. He says Guilt can be both as an ideation or a delusion. Although it is sometimes obvious when a delusion, we need to establish the fixity and firmness that a delusion has. Since a psychotic depression usually is more severe, we need to be pretty sure of that.
Answer: According to DSM-5 (American Psychiatric Association, 2013, p. 819) a delusion is a "false belief based on incorrect inference about external reality that is firmly held despite what almost everyone else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary. ... When a false belief involves a value judgement it is regarded as a delusion only when the judgment is so extreme as to defy credibility."
Similarly, Østergaard, et al. (2012), citing Maj, et al. (2007), state: "To avoid false-positive diagnoses of PD [psychotic depression], only beliefs that have 'delusional proportions', i.e. defy credibility, and are held with 'delusional intensity', i.e. not changed by rational counterarguments, are classified as delusions." (emphasis added)
An intriguing possibility exists that a specific, measurable cognitive bias,  the Jumping to Conclusions (JTC) bias, might serve as a marker for delusions (McLean, Mattiske, & Balzan, 2017). The JTC bias is characterized by making interpretations or judgments early (quickly) and basing such interpretations or judgments on inadequate evidence. Regarding measurement:

JTC is most frequently measured by the beads task. Applying this task
  with people with schizophrenia, Huq et al showed participants 2 jars
  of colored beads. Each jar contained pink and green beads in an 85:15
  ratio, with one jar containing mostly pink beads and the other mostly
  green beads. The jars were hidden from view and beads were drawn from
  one of the jars in a purportedly random but in fact pre-determined
  sequence. With each draw, participants were invited to indicate
  whether they had decided which jar (mostly pink or mostly green) beads
  were being drawn from. Huq et al9 found that participants with current
  delusions required fewer draws-to-decision (DTD) than those without
  current delusions, demonstrating a JTC bias. (McLean, Mattiske, & Balzan, 2017, p. 345)

Further research is needed before we will know if measuring JTC improves diagnostic accuracy.
Stephens & Graham (20014) describe four criteria that define beliefs generally:
(1) beliefs have a representational content;
(2) the person holding the believe has a high degree of confidence that the content of his or her belief, e.g., "I am a horrible person", is an accurately represents reality;
(3) beliefs form the basis for both reasoning and action, such that individuals draw conclusions based on the belief ("because I am a horrible person I am doomed to Hell") and might take actions based on the belief (a Catholic person visits a priest asking, "How do I prepare for an eternity in Hell?"); and finally
(4) beliefs are associated with an emotional response, e.g., a belief that one is a horrible person may engender or exacerbate feelings of sadness, shame, guilt, despair, or hopelessness.
This four-component model of beliefs can serve as a heuristic to probe the "delusional proportionality" and "delusional intensity" of a patient's beliefs, e.g., by asking questions designed to assess the patients degree of confidence in the belief; the extent to which the patient has drawn conclusions and taken actions based on the belief; and emotions experienced when discussing the belief.
Like many symptoms of mental disorders, if a clinician can observe and interact with a patient over time, and if the doctor can interview family members or friends who know the patient well, then determining if a belief qualifies as a delusional becomes somewhat easier.
References
American Psychiatric Association, 2013. Diagnostic and statistical manual of mental disorders (DSM-5®). American Psychiatric Pub. (ISBN 9780890425558).
Maj, M., Pirozzi, R., Magliano, L., Fiorillo, A. and Bartoli, L., 2007. Phenomenology and prognostic significance of delusions in major depressive disorder: a 10-year prospective follow-up study. The Journal of clinical psychiatry, 68(9), pp.1411-1417.
McLean, B.F., Mattiske, J.K. and Balzan, R.P., 2017. Association of the jumping to conclusions and evidence integration biases with delusions in psychosis: a detailed meta-analysis. Schizophrenia bulletin, 43(2), pp.344-354.
Østergaard, S.D., Rothschild, A.J., Uggerby, P., Munk-Jørgensen, P., Bech, P. and Mors, O., 2012. Considerations on the ICD-11 classification of psychotic depression. Psychotherapy and psychosomatics, 81(3), pp.135-144.
Stephens, G.L. and Graham, G., 2004. Reconceiving delusion. International Review of Psychiatry, 16(3), pp.236-241.


Set Default Listing "View" in Admin

Question: I'm looking for a way to set the default "View" options under post types in the admin area. For example, by default Posts will default to a "list" view instead of "excerpt" - I'd like to change this to excerpt by default - what would be the best way to achieve this? I've done a bit of searching on this, but am stuck in the mud thus-far. Any help would be greatly appreciated. Thanks!
Answer: Although having the feature of persistent settings in core is nice, it may take quite a while before it's actually accepted. WordPress 3.5 is still quite far away.
So let's augment the global $_REQUEST array instead.
add_action( 'load-edit.php', 'wpse34956_force_excerpt' );
function wpse34956_force_excerpt() {
    $_REQUEST['mode'] = 'excerpt';
}

This will lock up modes, forcing excerpt mode all the time, so let's turn let the user decide but keep it persistent using the user's metadata:
add_action( 'load-edit.php', 'wpse34956_persistent_posts_list_mode' );
function wpse34956_persistent_posts_list_mode() {
    if ( isset( $_REQUEST['mode'] ) ) {
        // save the list mode
        update_user_meta( get_current_user_id(), 'posts_list_mode', $_REQUEST['mode'] );
        return;
    }
    // retrieve the list mode
    if ( $mode = get_user_meta( get_current_user_id(), 'posts_list_mode', true ) )
        $_REQUEST['mode'] = $mode;
}

You can further interpolate post_type into all by taking into account the $_GET['post_type'] variable when available.
add_action( 'load-edit.php', 'wpse34956_persistent_posts_list_mode' );
function wpse34956_persistent_posts_list_mode() {

    // take into account post types that support excerpts
    $post_type = isset( $_GET['post_type'] ) ? $_GET['post_type'] : '';
    if ( $post_type && !post_type_supports( $post_type, 'excerpt' ) )
        return; // don't care

    if ( isset( $_REQUEST['mode'] ) ) {
        // save the list mode
        update_user_meta( get_current_user_id(), 'posts_list_mode' . $post_type, $_REQUEST['mode'] );
        return;
    }

    // retrieve the list mode
    if ( $mode = get_user_meta( get_current_user_id(), 'posts_list_mode' . $post_type, true ) )
        $_REQUEST['mode'] = $mode;
}

Viola! Persistent list mode per post type per user, no hacks.
Comment: Good solution. Got a much easier one shortly after I put a bounty on this! But, since you have the solution, I'll give you the bounty, although I think I'll incorporate your way instead as that is actually persistent rather than like the default behaviour except with excerpt instead of list. Edit, can award it in 17 hours so bear with me!
Comment: Thank you, glad to have been of help. A very interesting question.
Comment: Thanks for this @soulseekah, I used this too and works great. As you mentioned at the time "WordPress 3.5 is still quite far away" - is this code still good to use with latest WordPress version?
Answer: The post view screen switches from list view to excerpt view based on the value of the "mode" parameter in the query string.  If the "mode" parameter is not set, then WordPress defaults to list view.
Unfortunately, this parameter is not filterable, so there's no easy way to control it programatically.
So I'm going to do something I never do ... I'm going to tell you how to hack Core to make this work ...
Adding a filter
Open /wp-admin/includes/class-wp-posts-list-table.php and find the prepare_items() method (around line 81).
On line 99, WordPress checks to see whether or not the "mode" parameter was set in the request and uses this to set the global $mode variable:
$mode = empty( $_REQUEST['mode'] ) ? 'list' : $_REQUEST['mode'];

We're going to change this line to filter the default setting.  Change this line to:
$mode = empty( $_REQUEST['mode'] ) ? apply_filters( 'default-posts-list-mode', 'list' ) : $_REQUEST['mode'];

Now, go into your theme's functions.php file and add the following code:
add_filter( 'default-posts-list-mode', 'my_default_posts_list_mode' );
function my_default_posts_list_mode( $default ) {
    return 'excerpt';
}

This will hook in to the filter and return excerpt mode by default.
Since my personal rule about hacking Core requires that all hacks be contributed back to the project (this way they can be rolled into Core and no longer count as a hack), I've opened a Trac ticket for this enhancement and submitted the code above as a patch.  Please weigh in on the ticket so that it can get into core for 3.5 (we're too late in the cycle for 3.4, but we can try to push this through for the next version).
Comment: Very cool. Definitely think "this" is a reason to hack the core - so in the future, you don't have to :)
Comment: There's ongoing discussion on this ticket as well - plus a further patch proposing a user option instead of just a filter.  Please keep track of that conversation if you decide to actually hack Core ... because if/when things change in a future release, you'll need to change your code as well.
Comment: +1 for getting it on the road to core with some great patches, hopefully we'll see the changesets soon.
Comment: Why not just hack the `$_REQUEST` global on `add_action( 'edit.php', ... )` and the like, while we wait for core to adopt the patch/proposal?
Comment: @Soulseekah Good alternative ... just not a fan of hacking the `$_REQUEST` object myself. Feel free to post another answer outlining how it could be done.
Answer: Okay, so shortly after I put a bounty up, I came up with the following solution. It is the default behaviour in every way, except that it selects excerpt view for whatever post type you want (instead of the default list view).
<?php

add_action( 'admin_init', 'my_admin_init' ); // initiate admin hook

function my_admin_init() {
    // if mode is not set redirect to a default mode.
    if(!isset($_GET['mode'])) {
        if('forms' == $_GET['post_type'] || 'client-quotes' == $_GET['post_type'] ) {
            wp_redirect( admin_url( 'edit.php?mode=excerpt&' . http_build_query( $_GET ) ) );
            exit;
        }
    }
}

?>

NOTE: I recommend Soulseekah's approach, if you don't want it to remember the user's choice, you can incorporate my code with his code a bit.
NOTE 2: If/when EAMann's patch is part of the core, obviously his method would be the best one as it wouldn't require you to go the long way round. I just don't like it at the moment as you have to edit the core files.
Comment: My problem with this approach is that it involves a redirect. So you're loading WP not once, but *twice* just to get to the post listing page.
Comment: This makes sense. However, `paged` is not taken into account (pagination) + using `wp_redirect` instead of raw headers would might be a little "cleaner", and I'm not sure how efficient redirection is. Other than that looks interesting. Also, `$_GET['post_type']` might not be set, resulting in a warning if errors are turned on. +1 for the effort and the patience. Didn't realize the question was so old.
Comment: @Soulseekah, you're right, didn't think that through, I've updated the code to take into account all `$_GET` variables. As for the `$_GET['post_type']`, honestly, I wasn't too bothered with that as I only required it to be for a custom post type, which would always be there. Obviously this can be omitted.
@EAMann, You are right, however, this was the best solution I could come up with. I tried manually setting `$_GET` parameters, hoping that it would be set BEFORE it was read, but this didn't seem to be to the case.

Set Default Listing "View" in Admin


What is the purpose of the TDG gate in QISKit?

Question: The QISKIT documentation doesn't explain what a TDG gate does and I can't find it anywhere else online.
Answer: According to the QISKit documentation, tdg(q) applies the Tdg gate to a qubit.
$T$ is the basically the $\pi/8$ phase shift gate whose matrix representation considering standard (computational) basis is:
$$\left(\begin{matrix}1 & 0 \\ 0 & e^{i\pi/4}\end{matrix}\right)$$
Tdg is simply the conjugate transpose of the matrix $T$ i.e. $T^{\dagger}$, which is:
$$\left(\begin{matrix}1 & 0 \\ 0 & e^{-i\pi/4}\end{matrix}\right)$$
Thus, the $T$ gate would map the basis vectors (of a qubit) $|0\rangle$ to $|0\rangle$ itself and $|1\rangle$ to $e^{i\pi/4}|1\rangle$, whereas $T^{\dagger}$ would map $|0\rangle$ to $|0\rangle$ itself and $|1\rangle$ to $e^{-i\pi/4}|1\rangle$.
P.S: In case you're wondering what dg means in tdg, it is simply an abbreviation for "dagger" i.e. in the sense of $T^{\dagger}$ (pronounced as $T$ - dagger).
Comment: No answers since July, Blue?
Comment: @John Yeah, I was kinda busy with university work in the past few months. I'm also focusing a bit more on theoretical computer science rather than quantum computing these days. I will perhaps resume answering when my vacations begin. Have a good day/night.


Light fixture wiring issue

Question: So I'm attempting to replace an old light fixture with a new one I got from home depot. The light fixture is at the top of a stairway, there is a switch at the bottom of the stairs as well as the top of the stairs that control the light. Going into the overhead box there are 3 pairs of black/white/ground wires. Only on black wire is hot, every other wire has no voltage. Between the two switches are a set of  black/white/red/ground wires. The circuit that the light is on also goes to a small bathroom upstairs as well as a bedroom. How should I proceed wiring this?
I'll attach a few pictures to this to hopefully better clarify what i'm looking at.
Comment: Can you hit "edit" on your post (bottom left), then use the stylized-painting-of-a-mountain-and-sun icon to add your pictures to your question?
Comment: See where some wires are marked with black tape?  Did you do that, or did you find it that way?
Answer: New junction box, eh?  First, reinstall all cables in the junction box.
That trick with the ground wire wrapped around the sheath appears to be using the cable clamp to ground to the metal box.  Note the metal box will have a #10-32 tapped hole intended for a ground screw, and you can put a pigtail on that to ground anything else.
Now, identify which cable goes to the switch.   Mark its white wire with black tape, and its black wire with red tape.
Also mark the black wire from the new lamp with red tape.
Now you join similar colors: red to red, black to black, white to white, bare/green to bare/green.
Answer: You do not want to disconnect any wires except the two that go to the old light fixture, and the ground if there is one. Please tell me you didn't disconnect all the wires up there. Take the white from the fixture and hook it to the white from the overhead box. Take the black from the fixture and connect it to the black from the overhead box. If there is a ground connect that back up. You should be good to go..... unless you mixed them all up..
Comment: I have bad news...they're all disconnected
Comment: Couldn't upload the pics here.. this is what I have   https://www.reddit.com/r/askanelectrician/comments/dmq6yd/light_fixture_wiring_help_needed/
Comment: Why do you say to disregard the electrical tape in the ceiling box?

Light fixture wiring issue


What is the definition of small/large signal bandwidth?

Question: What is the definition of 'small signal bandwidth' and 'large signal bandwidth'?
If I google them, I only encounter them in an electrical context (transistors etc.). However, I am looking for a general definition (for any time signal).
Comment: Check this up:
[Small signal bandwidth explanation by Maxim Integrated](https://www.maximintegrated.com/en/app-notes/index.mvp/id/4295)
Answer: In communications, whether a signal is narrowband (has a small bandwidth) or wideband (has a large bandwidth) is relative to the channel's impulse response.
If the channel behaves as a flat filter (constant gain) over the signal's bandwidth, then the signal is narrowband. If the channel introduces significant distortion (that is, if different signal frequencies see different gain) then it is said that the signal is wideband.
Comment: @Karlo That is my point exactly. Note that what I said is true in communications; I don't know if there are other definitions in different fields (I'm not aware of any).
Comment: I thought that *small signal bandwidth* and *large signal bandwidth* were specific characteristics of a given signal (as in *signal 1 has a small signal bandwidth = ... and a large signal bandwidth = ...*). But if I understand you correctly, there exists only a *signal bandwidth* (which I know), that can be small/large (relative terms).
Answer: Do you perhaps mean small signal model?  That is often used in the context of analysing the performance of transistor circuits.  The transistors themselves are nonlinear devices, but they can be analysed as linear devices if you choose their operating regime appropriately.
Conversely, the large signal model is when the operating regime is such that the nonlinear effects must be taken into account.


Damaged hard disk - FAT32 - lost boot sector and root directory

Question: I've got an external 640Gb HDD which has been badly treated (accidentally packed into a sea shipment container then left in storage for 9 months, probably had some extreme temperatures too). I'm trying to get the data off it with limited success. So far I've managed the following using a debian box I have available:
Image - Worked:

ddrescue to create an image (took about 10 weeks with a few crashes
where the errors during reading overloaded my system, most errors
occurred in three blocks at the start of the disk, about 1/3 of the
way in and about 3/4 in)

Partition table - worked (sort of):

testdisk - cannot find any sensible valid partitions (shows a few
which overlap and do not fit within the disk geometry)
so I checked the orginal disk table using parted and created a
replica in the image file. The values seem reasonable (starting
sector 63, end at end of disk, type FAT23-LBA)

Recover data - failed (sort of)

fsck.msdos -rv give mismatches between the two FATs, I've tried using each of them and then mounting. Mount doesn't give any errors but the mounted directory is empty
testdisk tells me that the boot sector and backup are invalid and then goes off to try and recreate it. Unfortunatley it doesn't find the root directory when searching (it comes up with plenty of suggestions but nothing in the first half of the disk or that has the right number of entries)
photorec - recovers about 450Gb of data, mainly riff files (which makes sense as most of the data was .avi) but no usable filenames.

So 450Gb of randomly names avi files - not much use. I tried using extract to pull the metadata from a sample of a few files but none of them have a "Title" tag or similar.
What I think has happened is that the root directory was at the start of the disk and has gone completely, so when mounting there is just emptyness.
Ideally what I would like is to either:

recover files in their directory structure (coping with the fact that everything will at some level be an orphaned directory) or at least with original filenames
identify the files based on their contents without sitting watching them all.

Does anyone know of any tools which can do either or am I stuck with what I've got so far?
Thanks
Comment: At least your porn is safe.
Answer: use testdisk
http://www.cgsecurity.org/wiki/TestDisk_Download
it might help you,,
you may recover it
it might take time to complete the operation......
All the best


Can't share my folders in XP

Question: I have an XP machine. I have shared folders in my system. When I am accessing my shared folders from other systems I can view the shared folders but when I am trying to access them, it's showing an error message saying it can't access the folder, you might not have permission. Even the c$ share is showing the same error.
I can access shared folders from all other systems.
Answer: Maybe the firewall on either machine, or a machine in between, is blocking file sharing.
Answer: You're saying that your workstation, A, has shared folders, but another workstation, B, can see the shares but you can't access them, yes?
You might have a permission problem then.
Check in your shares tab that the share has permissions for others to access that share name.
Then check the directory to see if the NTFS permissions allows for others to access that directory.
In other words...
I have a computer where I create a folder called c:\shared. I open its properties and share it, and in the share I set the permissions so "everyone" has access. just because the SHARE has everyone access doesn't mean they can get into it!
Now I open the security tab for the folder c:\shared. If the NTFS permissions are set so only administrator can access the folder, then only Administrator can access the share remotely. I have to set it so "everyone" (or whoever you want to have access) can read the c:\shared folder.
Essentially for shares permissions are an onion. You need both layers of skin to allow proper access. NTFS is finer-grained for permission tuning, so I normally set my share permissions to everyone and control access to the folder using the NTFS filesystem permissions.
Also make sure you are accessing the share from the remote system with a username that matches what you have on the first workstation or you have to enter the proper credentials.
Comment: thanks for the reply. i set NTFS permission to every one. still the same problem.

Can't share my folders in XP


Should answers be left in the comments?

Question: Sometimes users leave comments on questions that are essentially a short answer to the question. What is wrong with answering a question in the comment section?  Is it ever appropriate to leave an answer in the comments?
Comment: No, they really shouldn't.
Comment: Because comments cannot be downvoted, I hereby dedicate this comment for receiving upvotes from those who disagree with @enderland's comment above. Offer valid unless and until that comment is deleted, at which point any upvotes on this comment retroactively amount to agreement by the upvoter of this comment to send me a large sum of money (exact amount at my discretion). ;-)
Comment: This has now been asked on meta.SO, where the majority (bafflingly) seem to think it's a fine and dandy way to behave! http://meta.stackoverflow.com/q/335190/560648
Comment: Related on meta.photo.SE: [Short answers as comments — please resist the urge](http://meta.photo.stackexchange.com/q/4655/34807)
Comment: Thanks for the heads-up, @LightnessRacesinOrbit.  I've upvoted your answer over there.
Comment: Related on interpersonal.meta.SE: [Please don't write answers in comments.](https://interpersonal.meta.stackexchange.com/q/1644/1570)
Comment: On aviation.meta: [Should Aviation.SE allow answers posted in comments?](https://aviation.meta.stackexchange.com/q/3553/112)
Answer: Answers to questions should be posted as an answer, not a comment.
What is wrong with answering a question in the comment section?
Stack Exchange websites are sites focused on questions and answers.  They have a lot of community features that make them better than other types of sites:

Questions and answers can be edited (improved) later, either by the original poster or anyone else that has an improvement.
Questions and answers can be upvoted and downvoted by users, ensuring that the best information is at the top.
Users can ask questions about the answers, asking for clarification or refuting information, by leaving a comment for a specific answer.
Reputation can be earned for good posts, and lost for bad posts.
Answers are essentially permanent; they are generally only deleted by a moderator if they are not appropriate for the question.  Even after they are deleted, they are still visible on the site for high rep users and can be undeleted if necessary.
The person who asked the question can select the answer they thought was the most helpful and accept it.
When a new answer is posted, the question is bumped to the top of the front page, notifying everyone about the new answer and inviting community moderation.

Posting an answer in the comments breaks all of these features:

Comments cannot be edited by anyone, even the user who left the comment.
Comments cannot be downvoted and are sorted by post date, not by score.
Although you can leave a response for a commenter, comments are not truly threaded, and you can't leave a comment on a comment.
Reputation is not changed for good or bad comments.
Comments are intended to be temporary.  If there get to be too many comments, moderators will sometimes delete all the comments or move them to chat.  My understanding is that moderators have a "Purge Comments" button, which tells you how easy it is for comments to be deleted.
Comments cannot be accepted by the OP as the best answer.
New comments do not bump the question, which means that comments get less attention than new answers.

It can be tempting when you see a new question that doesn't have any comments yet to leave a one-sentence answer as the top comment.  That way, you get your opinion in early, your post will always be first at the top of the page, and you don't have to worry about anyone downvoting your "answer."  But that is not how this site is supposed to work, and doesn't leave your "answer" open to the community moderation features.
Is it ever appropriate to leave an answer in the comments?
Sometimes people think that a one-sentence answer is too short to be posted as an answer.  If you are saying so little in your answer that it is too short to be posted as an answer, you should ask yourself if there is any value in posting it at all.  If you are essentially leaving an opinion without providing any justification for that opinion, perhaps you should upvote a different answer instead of posting your own.  If you don't have time to post a better answer, then wait until you do have time.  On the other hand, perhaps the question is simple enough that a short answer is enough; if so, post it as an answer.
Occasionally, you might ask the question asker for clarification, and in the process stumble upon the answer in the comments.  At that point, you should write an answer and post it as an answer.  Here is an example of a time that I did this on a different SE site.
What if I'm not sure if my answer is correct, and I'm only speculating?
If you aren't sure of your answer, it is even more critical that you post it as an answer, not a comment.  The reason is that you need to allow your possible answer (which may or may not be correct) to be moderated by the community.  Other users should be able to vote it up or down and to leave comments explaining why it is or is not correct.
What if it is a link-only answer?
The reason link-only answers are discouraged is that they have a tendency to become worthless when the link goes dead. Posting these as comments is no better than posting them as answers. In fact, it is worse; as an answer post, the link has the possibility of being edited in the future if necessary, but as a comment, it can never be edited.
Instead, feel free to post your link in an actual answer post, just be sure to include a summary of what the reader will find on the other side of the link that answers the question.
Comment: If the person doesn't feel their reply merits an answer post instead of the comment, then its up to them. If anyone feels the comment is a good answer, then it can be converted to a full answer, but that shouldn't be the first knee jerk reaction. There is enough half baked and cluttering crap that passes for answers on the sites, I don't want to contribute any more to that mess. That's just me.
Comment: I saw the original comment and I also felt "this doesn't need any editing, it's a good answer as is." And I also understand the odd situation when someone doesn't wish to post an answer, feeling their own comment doesn't live up to their own standards of good answer. Forgive me for the wishy-washy coment.
Comment: @GµårÐïåñ If a post is half-baked and cluttering, it doesn't belong in the comments, either.  The problem is that you can't downvote a bad comment.
Comment: I never said my answer was cluttering or half baked, just concise in favor of the fact that I have put way more detailed information out there that can be read instead, don't feel like repeating myself but a short concise answer gets the OP on their way and won't clutter with a bunch of answers. There is a place for answers and there is a place for comments, and I think that's up to the person. That's why during the "flagging" process there is a : "this is not answer and belongs as a comment" for a reason, not everything rises to the level of an "answer" posting.
Comment: @GµårÐïåñ To be clear, I didn't call your answer/comment half-baked or cluttering, either.  On the contrary, I think it should be an answer.  But it is an inappropriate comment, for the reasons I stated above.  Just my opinion, of course.  Feel free to post a new answer to this meta question if you disagree.
Comment: I will take issue with "its up to them".  Stack Exchange in general does _not_ allow for this; the original poster of a question, answer, or comment does not merit any special consideration as to whether their answer or comment is appropriate. An answer is an answer and a comment is a comment. C.f. the expectation that a user not roll back edits on their posts that improve the post, even if they disagree with those edits.
Comment: @BenMiller Yes, moderators have a "purge comments" button-of-sorts. It's actually a dialog of options, similar to the flag or vote-to-close dialog, but the functionality is there and works like you think it does (assuming that it hasn't been *radically* changed in the last few months). There's also "move comments to chat" right next to the "purge comments" option. Source: I had a diamond on [worldbuilding.se] until February of this year, and on [ham.se] for some time before that.
Answer: EDIT - We have an example in the wild that raises an issue tied to this question. Friend was brainwashed with MLM-/ponzi investment scam. What can I do? had a comment -

Go to the police. This is fraud and is illegal. Sure, this will hurt
  your friend but better now then when he starts abusing of his position
  to fraud even more people...

Which another, new, member copied and posted as an answer. Another member flagged it to the mod's attention. Ganesh and I discussed it, and agreed that if the answer is simply a copied comment, it should have attribution to the comment author. If it's turned into an edited, expanded, comprehensive answer, attribution may not be as big a concern. Is this approach satisfactory?

For sake of my 'answer', let's assume I agree, and start with No (as I agree with your concern).
The real question may be, "How should we handle comments that are really answers?" Right? Else, we simply agree with you, but have no consensus how to handle this.
The option for a mod to "convert to answer" doesn't exist, we do not have that option as we do for "answers that are really comments," that we just flip to a comment on the OP question. The implication here, is that a flag on such a comment is really a request to delete it.
Another option is that a member take the ball and run with it, copying the content, and hopefully adding a bit to it, to make it a good answer.
Third choice is for a further comment to prompt the OP to change it to an answer himself. This is what I typically do, and more often than not, it happens.
My concern is the gray area. One example offered in another answer was a link-only answer. That answer would be voted down as link-only, or converted to comment. But here, it seems that some would consider it too-good-for-comment. Which then will just lead to more discussion on something that I haven't seen as a major issue, yet.
Update - I wrote myself a macro for a comment reply for this issue -

Fill in member name - this comment is "too good to be a comment" -
  please consider deleting it, and write it as a full answer to the
  question. See the meta question Should answers be left in the
  comments?
  for more details.

I just used it at Rent at $1500/month in Toronto or Mortgage even with ≥ 5% interest? and the OP complied. (The example in the wild is now deleted)
Please comment below if you have any advice to improve this line.
Comment: "Another option is that a member take the ball and run with it, copying the content, and hopefully adding a bit to it, to make it a good answer.  Third choice is for a further comment to prompt the OP to change it to an answer himself. This is what I typically do, and more often than not, it happens.."  I have done the first a few times (mostly on other SE sites) but only when the writer of the comment has (usually by inaction) declined the suggestion to convert the comment into an answer. I have always made sure to check the "Community wiki" box so that I don't earn reputation from the answer
Comment: The dilemma you describe is exactly why I wrote this question: to discourage people from doing it in the first place.  What often happens is that someone leaves a controversial answer in the comments.  It might get some upvotes, but of course, no downvotes, and generates some discussion.  All of a sudden, the comment space that is supposed to be left for communicating to the OP is now on a side discussion about this "answer."
Comment: And the mods are then required to be the judge as to whether or not the "answer" is bad enough to be deleted, based on its content.  Mods, in my opinion, should not be put into a position where they are required to be the sole judge of whether or not an answer is correct.  I don't know if we need a zero-tolerance policy like Joe's answer or not, but certainly an occasional "no answers in the comments" reminder and a pointer to this meta question are warranted.
Comment: I like your macro reply, but keep in mind that an answer/comment could also be "too bad."  The "good" answer/comments aren't as much of a problem as the bad ones, or at least, the controversial ones, because they can only get upvotes and not downvotes.  If you ran into an answer/comment that offers questionable advice, would you still leave this reply, or would you do something different?
Comment: Thx. Yes, the macro was just for prompting the good commenter. I haven't given the flip side enough thought. A bad-answer-as-comment should probably just be deleted, and not encouraged to be expanded into a bad answer.
Comment: The other thing I have done is to answer with "Community Wiki" so I don't get any "points" for the answer.   Here's an example of what I've done in the past: http://money.stackexchange.com/questions/62392/new-car-vin-number-changed-for-rav4-limited-hybrid-black-exterior-at-the-toyota/62429#62429
Answer: See past discussion.
In principle you are correct, answers belong in answers.
In practice there will always be disagreement whether something is a comment or answer, with no reliable line between them. Reality is fractal; human behavior more so.
If you really think a comment should be an answer, you are free to turn it into one by quoting it in an answer of your own (properly credited, preferably). If it isn't worth your effort to do so, it isn't worth complaining about; accept that the world is imperfect and let it go.
(I should also point out that the short responses you say should be Answers often draw complaints about "that should have been a comment." Unless you want people to stop contributing entirely, there is no perfect solution here. It's working well enough. Let it work.)
Comment: Agreed. There are also times when someone is not very sure and would tend to leave a comment more to help the OP and other who know the subject. There were time when I have requested someone to post his comment as answer and it was accepted. There were one or two occasions when someone asked me to change my comment to an answer that i did. So I guess its working fine.
Answer: A comment that is clearly an answer should be deleted, full stop.  Comments are not appropriate locations to give answers.  Answering questions in the comments is harmful for the site; it ends up with questions that go unanswered, and it ends up with people thinking the site should work more like a forum.
A comment that gives the appearance of an answer but might be understood not to be sufficient for an answer... also should be deleted, if it's just answering the question and not clarifying the question.  Comments are for clarifying the question.
So, for example, here:

Q.  How can I do my taxes online?

C.  The IRS has a page to help you out, www.doyourtaxesonline.com.

That's an answer, and should be deleted.

Q.  How can I do my taxes online?

C.  Have you seen www.doyourtaxesonline.com?

That's not helping clarify the question - it's more-or-less an answer.  Whack.

Q.  How can I do my taxes online?

C.  Are you looking for something like www.doyourtaxesonline.com?

That's potentially clarifying, so it's fine - but I'd remove it once the clarification is received, and the comment poster has a chance to post it as an answer if that is indeed what they're looking for.  This is what I'd consider a 'borderline' case.

Q.  How can I do my taxes online?

C.  What country are you in?

That's clearly a clarifying comment, and should stay until the clarification is received and then be subject to removal, as with any other now-irrelevant comment.

I imagine the point is clear: I support keeping comments as clean as possible.  If they're clarifying something with the OP, they should be kept until that clarification is received.  If they're chatting, answering, maybe-answering, or anything else, they should be removed whenever a mod is around who feels like removing them (or moving them to chat if appropriate).
Comment: And yet "The IRS has a page to help you out, www.doyourtaxesonline.com" is basically a link-only answer. Many would suggest it be converted to comment. Others would say "could you offer some text, as this is link-only." This is a tough one, and the examples prove it.
Comment: If you think a comment should be an answer, feel free to quote/copy it into an answer. If it isn't worth your effort to do so, it isn't worth getting irate over. Lead by setting an example, not by complaining.
Comment: Not minding when comments are deleted is different from setting a policy that has to be enforced by a few moderators. We need to relax our crackdowns against short answers if we're going to try to police comments on any more than the "hot" questions that attract long side-conversations.
Comment: @JoeTaxpayer Well, sure, it's also not a good answer - but that's part of the point. Something may be both not a good answer *and* not a comment.
Comment: I don't think that comments that could be answers should be deleted until the information is included in an answer (whether by the commenter or someone else). Once that's done, they're obsolete. Until that's done, they're helpful information that could be used to improve the Q&A.
Comment: It's not the design of StackExchange that moderators should be expected to, or forced to, decide the correctness of a comment or answer or anything else.  That is *precisely* the point of what I suggest here: moderators should feel free to remove them _automatically_ without needing to judge their correctness.  Answers can be voted on.  Comments cannot.  Sure, anyone who sees such a comment should feel free to make an answer from it - but that doesn't impact the deletion of the comment.
Comment: Right. So if they are automatically removed, the bad comments are no longer a problem. I'm sorry, I really don't see much that needs fixing here.
Comment: I will note that realistically, I don't expect people to behave this way initially 100% - I certainly use comments for things I really shouldn't from time to time, as does everyone; that's human nature.  But I don't at all mind my inappropriate comments being deleted, and often do delete my own comments when I realize they are inappropriate (or, more often, when they've served their purpose).
Comment: @NathanL I don't see why we can't have good answers *and* use comments appropriately.
Comment: @GaneshSittampalam I don't mind waiting a bit, but what I don't want to see is comments like this hang around because nobody ever chooses to put them in an answer.  It also encourages question askers to get their answer from comments and then leave - meaning the real answers never get the attention they need.  The faster answer-comments are nuked, the better for the whole site.
Comment: @keshlam The problem isn't so much a good answer in the comments, it is more when there is a bad answer in the comments.  It can't be downvoted.  No one will copy it into an answer if they don't agree with it.  It can't be downvoted.   The mods are then forced to be the judge of its correctness and decide whether or not it should be deleted or kept.
Comment: And you distrust the moderators because...?
Comment: @keshlam I don't distrust them, it's just not in their job description to delete answers they don't agree with.
Answer: The incentive already exists to leave an answer rather than a comment. Comments can get upvotes but no points are awarded. Similarly comments cannot get downvotes. Would a downvoted comment have sufficient penalty if there are no points deducted?
Comments can be deleted without moderator attention if 3 (+ the number of upvotes) users flag them, that's lower than the threshold for close votes. The problem with an effort to enforce this rule is that unless multiple users are flagging comments all the time, this falls on the moderators. Unless there are enough users committed to policing comments, then we won't likely see progress here.
I agree with others who have mentioned that the line between a good answer and a helpful comment is pretty fuzzy, and I don't agree that comment answers are terribly harmful. I think a good answer with upvotes deters other answers more than a comment answer does. At least a comment answer can point a user in the right direction even if it doesn't take the time to fully explain why.
All that said, given the lower value of comments on stackexchange, deleting comments will probably hurt less feelings than deleting answers and closing questions.
Comment: Exactly. In my opinion, flagging should be for something that has a level of urgency. Spam should be flagged. When a member calls another member a stupid #$^7*)#$ I don't mind a flag. A "this is not an answer, but should be a comment" is ok, as I typically agree and move it. But keep in mind, we don't have the power to convert comments to answers, so in effect a flag is a request to delete a comment. Because it's too good for its own good.
Comment: I intended to hint that the lack of automation was an implication that there was no strong need site-wide for it. I suppose one can copy and expand on the answer and basically take credit, but I was thinking more of the conversion, same as the other direction. I didn't really think this practice was so widespread, although I know I occasionally write "you can turn this into a great answer"
Comment: You do have that ability; you just don't have automation or a way to give the points to the original author. ***Not everyone cares about points***, and if we have posted as a comment that can be considered permission for someone else to claim them. (I would appreciate being credited by name, but I don't insist on that either.). If folks really think automation is needed, I'm sure someone can write a Greasemonkey script to implement that... heck, if there's serious interest I'll take a swing at that myself.

Should answers be left in the comments?


Traveling to Cancun through Zurich as the non-EU spouse of an EU citizen

Question: I am from Colombia. I am married to an Italian. I live in Italy. We would like to travel to Cancun through Zurich. Do I need a transit visa?
Answer: While I don't have any personal experience with this particular scenario, you probably don't need a visa because as a permanent resident in a Schengen country, you can travel to other Schengen countries for three months in any six-month period (and Switzerland is part of the Schengen area, even if it's not a full member of the EU). This is completely independent from the fact that your husband is Italian. Make sure to have the relevant residence permit with you (and a valid passport but since you are going to Cancun, I assume you will have one with you in any case).
One caveat is that you only said you are "living" in Italy. Are you a permanent resident there? Does your husband live there with you? Traveling with your husband or having a residence permit mentioning the fact that you are the relative of a EU citizen is sometimes required to travel in the EU without visa (albeit not in the Schengen area itself where, per the rule cited above, a regular residence permit alone is enough). If you want to be absolutely sure, you could contact the Swiss consulate for your region and ask them directly.
If the previous conditions do not apply, getting a visa as the spouse of an EU citizen should be quicker, easier (e.g. no health insurance or bank statement should be required) and, importantly, not cost you anything.
Source: Travel documents for non-EU family member on the EU general website.
If all fails, the EU could also offer some assistance. You could probably also use the first option ("Quiero saber más sobre mis derechos según la normativa de la UE en la situación en la que estoy"/"I want to know more about my rights under EU law in a situation I am currently facing") and ask the same question there.
PS: Note that rules regarding "airport transit visa" do not apply for this travel as you will be leaving the international zone of the airport and entering the Schengen area in Zurich. If you had no residence permit, you would need a full Schengen visa and could not rely on the transit exemption or apply for a transit visa.
Answer: No. Assuming you have a permit for Italy - or any Schengen country for that matter - you do not need any visa. So long as you're not staying for longer than three months, you don't need any visa for Switzerland.
Me (EU citizen) and my Israeli partner (who has a permit for an EU country) have used (the Swiss sector of) Basel airport to fly to within and outside the EU on multiple occasions, and we have never run into any visa issues. Residence permits issued by Schengen countries allow the holder of said permit to freely visit every Schengen country for up to 3 months each 6-month period. Switzerland is a Schengen country.
One note is that the Swiss are keen on checking (non)declared goods. Upon entering Swiss territory (also by car or rail) you might be subject to a border control. If you are carrying certain goods, they must be declared (and pay taxes). But if you are taking normal travel items, there is no need to worry.


How to turn off passwords?

Question: When I start Firestarter, the firewall program asks for my password. How do I turn off my Firestarter password?  I want Firestarter to start on computer startup but it won't because it's password protected.
Answer: Firestarter is a program for editing your firewall rules - the firewall is part of the linux kernel and will automatically start whether or not you run Firestarter.
So, you don't need to do anything with passwords to have a firewall - it's already there.  In fact, you should keep your password enabled, since that way no one but you will be able to edit the firewall rules.

How to turn off passwords?


When were the first mosques established in Constantinople?

Question: In his book The Man of Numbers about Leonardo Pisano (Fibonacci), Keith Devlin quotes a problem from the Liber Abbaci (Devlin's spelling, I know most others spell it Liber Abici) which is titled "A Problem Proposed to Us by a Most Learned Master of a Constantinople Mosque". As Liber Abbaci dates to the early thirteenth century (first edition predates the sack of Constantinople by the Fourth Crusade by about 2 years), I want to ask about the date/s of establishment of Mosques in Constantinople?
Comment: @T.E.D. All medieval universities (never mind the churches and monasteries) throughout Europe used Latin for several subsequent centuries so your death of Latin has been exaggerated.
Comment: AFAIK, the first mosque in Constantinople was built in Chalcedon (Kadıköy)  when the Ottomans conquered the Asian part of the city in 1353. That's over a century after the first publication of Liber Abaci in 1202.
Comment: Is it possible that bit was mistranslated? From the title, I gather that work was in Latin, which ceased to be a living language before Mosques existed.
Answer: According to this article, there are letters to and from a mosque in Constantinople in the 10th century. with speculation it was built for merchants from Muslim countries, as well as for dignitaries, in times of peace between Muslim middle east and christian Byzantine.
Comment: there is also speculation that their was a mosque built outside of the city's walls, during a siege in the 700's that was left up by the byzantine ruler.


apply to or for, and apply to for

Question: In the Oxford Learner's Dictionary's meaning 1, what is the difference between apply to and apply for, and what is the meaning of (for something) after apply to somebody/something? What element of clause structure is it, like complement or adjunct? And does it have the same meaning and structure as make application to somebody/something for something in this dictionary?
Answer: 'Apply to' should be followed by the person(s) who will approve or reject the application.
'Apply for' should be followed by what is received if the application is approved.
Comment: @Orient My personal choices would be either 'applied for the program' or 'applied to be admitted to the program'. I'm afraid there are no fixed rules in English for the best choice of prepositions. Differences of opinion exist, especially between British and Americans. I cite a contrary example from the merriam-webster.com definition of 'apply': to apply for a job. I certainly agree that this is correct: Which colleges have you applied to?
Comment: Then how about these sentences in [this dictionary](https://idioms.thefreedictionary.com/apply+to) (meaning 4): I applied to the scholarship program, but I haven't heard anything back yet. Which colleges have you applied to?
Comment: In the context of scholastic programs, the thing being *applied for* is admission, which is typically elided. The person/institution responsible for accepting or rejecting the application is what is being *applied to,* and what is explicitly discussed.

apply to or for, and apply to for


Scale length with incorrect bridge position

Question: What would be the issue/effect of having the bridge too far away from the nut on a large fretboard with standard fret sizes? For example, a 24 fret board with 25.5 inch scale fret spacings, but a bridge 28 inches away?
Comment: See this [**calculator**](http://www.stewmac.com/FretCalculator)
Comment: Is this just a theoretical question? As a guitar neck is not adjustable in length or size of frets, thus fixing the bridge in only one optimum position.
Comment: @Tim  What about guitars with adjustable bridges as with a fixed tailpiece.
Comment: @RockinCowboy - Why would anyone want to put a bridge in anywhere except the right position? No guitar is going to play in tune like that.
Comment: @topomorto - changing a neck for one of a different scale is, I imagine, quite rare. A similar neck from the same model would make sense, but otherwise major surgery probably wouldn't warrant such a swap.
Answer: Not only would your fretted notes play flat, but as you go further up the fretboard, the flatter your notes will get!
Answer: All the notes would play flat (lower in pitch). The 12th fret (for example) should normally be halfway along the string, so that it sounds an octave higher than the open string. If the bridge saddle is further from the 12th fret than the nut is, the 12th fret would play a pitch lower than the octave above the open string.
Comment: Thanks. I suppose the saddle screws are for fine intonation adjustment. Well, that sucks! I really want a huge neck but can't get the bridge close enough.
Comment: @LukeFaez Get a cheap second-hand guitar and do some woodworking. or stick a guitar neck on an old bass...  or any old plank of wood...
Answer: The fret spacing (distance of each fret from the saddle) is very precise for any given scale length.  Many guitar manufacturers stick with common scale lengths so they don't have to constantly re-calculate the fret spacing.  But the scale length varies between guitar builders and some even offer options for different scale lengths.
Moving the bridge even a tiny bit will totally change the intonation and result in a new tuning that will not sound correct with any other instrument. You will be able to get one fret to play in tune, but all the other frets will be out of tune.
Even guitars such as an arch top that have a movable bridge must have the bridge located in precisely the correct location.  If a movable bridge gets knocked out of position, and there are no markers on the top to aid in placing it back in the exact place where it is supposed to be, then you can find the correct place by playing a harmonic at the 12th fret and comparing the sound with a fretted note at the 12th fret.  Keep moving the bridge until both notes are the same.
The only way to get the guitar to play in tune if you move the bridge is to move each fret to the precise location it will need to be in for whatever new scale you create.
You could use a neck for a baritone guitar which is set up for a longer scale and place the bridge in the exact spot for proper intonation, checking with the 12 fret harmonic method mentioned above.
An experienced luthier will know the mathematical formula to calculate the exact fret locations for any given size scale.  But in order to make that work with standard measuring devices, there are probably numbers that work better than others for scale length measurements.
Comment: The formula for frequency (in equal tempered intonation) is simply that a semitone is a frequency ratio of the twelfth root of 2. Thus both the scale length and the fret spacing diminish by this amount for each successive fret. This doesn't take into account the effect of string stretching as it is bent to fret the note, but using the theoretical ratio and posiitioning the bridge to compensate would probably be good enough. Apparently the luthiers of the renaissance used 18/17 as a ratio, although this is a whole cent too narrow.
Answer: As already said, this will completely change the tuning on all frets. So, the only way this could be usable is if you want to play in a tuning other than the western standard 12-edo. If you move the bridge only slightly, the lower frets will still make up an approximately equal-tempered tuning, just with another step size. Making the scale a bit shorter could thus give you an 11-edo tuning – 10-edo would already be problematic because the higher frets stop giving the same frequency ratios. Increasing the scale could give you 13-edo and 14-edo.
All those tunings are pretty exotic, I don't think you'd likely have much fun with them! Though there is one tuning you can achieve this way that I find quite fascinating. It's not an edo-tuning but an edt-tuning like Bohlen-Pierce (i.e., it does not have octaves at all, only tritaves). It is the 17-edt tuning.
I actually have a guitar modified for that tuning, by inserting a secondary "bridge" over one of the pickups:

An example of how this can sound:
Comment: I'd love to say something more about this, but frankly I haven't finished anything else yet in 17-edt tuning. There's a lot of handwritten ideas, some sketches about how the theory would work out, but nothing really definitive. I've occasionally just tried improvising something on the guitar, but to little avail. Trouble is, you basically need to purge everything you know about western music from your mind: because the chromatic steps in 17-edt are so similar to 12-edo, you easily end up playing detuned _diatonic_ melodies instead of scales that make harmonic sense in the odd 7 (or 11) -limit.
Comment: Wow, this is really interesting. I'd love to know a bit more about the kinds of sounds/music you create with this instrument. Just not sure that a comments stream is the best way. Maybe another post...?
Answer: You could possibly get this to work by having a temporary bridge - possibly just a piece of wood with an acoustic guitar saddle strip - resting on the belly of the guitar.  It would be held in place by the string tension.  It would be necessary to take out the existing bridge saddles etc.  The rest of the bridge would remain to anchor the strings.
It would be extremely ugly though!  You would have to forget about using your tremolo, if you have one.
Comment: banjos have a bridge which just rests on the skin and thus is very easily moveable. One thing that is frequently overlooked when restringing a banjo is proper positioning of the bridge to achieve correct tuning on the higher frets.


Difference between srIvidyA upAsanA in Vedanta and in Tantra?

Question: Recently I came to know from one of my friend that srIvidyA upAsanA is also done in Vedanta. While I am aware that srIvidyA is Tantrik upAsanA. I was unaware of Vedantic one. Also as far as I know, srIvidyA upAsanA is fruitful when done by both i.e. husband and wife. So how does Vedanta which promotes Sanyasism, do upAsanA of srIvidyA ?
Comment: @Partha I am not aware of Kaulopanishad. But yeah I am aware of Kaula Tantra.
Comment: Never heard of Srividya in vedanta. As far as I know, it is part of tantra.
Answer: In the worship of Sri-Vidya, there are three ways(Matas)-- Samaya-mata, Kaula-mata and Mishra-mata.
In the commentary of the Saundaryalahari (sloka 31), Lakshmidhara writes

The graceful God Pasupati has recommended different Tantras for the four main and mixed varnas. These Tantras are NOT for the brahmins following the Vedas.For the followers of the Vedas,Lord Pasupati has composed 'Suva-Aagama-Tantra-panchaka'. Vasishtha,Sanaka,Suka, Sananda and Sanatkumar--these five munis have followed this path known as the 'Samaya-aachaara'.

Sri Panchanana Tarkaratna writes in this regard

Samayachara involves only Manasa-upaasana or Internal Worship.There is no provision for external worship.

So the Samayacharis do not have any purascharana, japa, homa or external pujavidhi.
There is no restriction on the Kaulaachari-s also.Lakshmidhara opines that yogis who concentrate on the sushumna are the real kaulas. However, some samayaacharies do not accept the Kaulaachaara as a path to be followed by the Vedic brahmins.
So to conclude, the brahmacharins and sannyasins are allowed to do Sri-Vidya sadhana, but the path is not purely a Vedantic one., even though we get mention of the 'Kaula-Upanishad' and 'Bhavana-Upanishad'.
According to some views, Sri Adi Shankaracharya Himself did practise Sri Vidya Upasana by the way.
Reference: Sastramulak Bharatiya Shaktisadhana, Upendrakumar Das,RMIC, Vol.1, chapter 12.
Comment: give your e mail


Does 3D Thrust vectoring (TVC) provide improved maneuverability over 2D TVC?

Question: What are the additional capabilities that 3D thrust vectoring (TVC) provides over 2D thrust vectoring?
Comment: define "much better". in its current state this question is heavily opinion-based.
Comment: its more specifically in terms of maneuverability..
Answer: Thrust vectoring allows to control an aircraft when the airflow over its control surfaces has separated. Before thrust vectoring, the range of angles of attack in which an aircraft could be controlled was rather restricted.
With the X-31, it was for the first time possible to control a completely stalled aircraft, which enabled much quicker maneuvering in order to get the nose pointed at an adversary. This was powerfully demonstrated by mock air combats with an F-18. The X-31 used a rather simple arrangement with three paddles at the engine exhaust, and this allowed to create both pitch and yaw moments. This makes it what you call a 3D thrust vectoring aircraft.
Modern thrust vectoring nozzles are round and allow to deflect the thrust by up to 20° in both pitch and yaw, making them also what you call 3D. However, this geometry will scatter radar waves in all directions, which makes it unsuitable for stealth aircraft. Therefore, stealthy designs can use only two straight vanes above and below the jet exhaust, which will create only pitch moments. This is what you call 2D thrust vectoring. When two engines are installed, differential deflection will allow to create limited roll moments, but the powerful side forces which allowed the X-31 to rotate its nose (and radar) quickly into the path of its adversary will no longer be possible.
Stealthy thrust vectoring will still allow to control the aircraft at all angles of attack, but the yaw rates possible with a regular thrust vectoring nozzle are no longer achievable. This, and the structural mass of a rectangular exhaust, are the distinct disadvantages of stealthy nozzle designs.
Comment: @JanHudec: Done, but those terms are not really appropriate. They are more from pop culture than engineering.
Comment: You should state which is the 3D and which is the 2D variant.
Comment: Yes. But they are in the question, so they need to be mentioned.
Answer: In short, yes; the ability to vector thrust to the sides of the aircraft, inducing yaw, does provide an advantage in maneuvering over pitch-only vectoring.
Consider the Su-30 "SM" and "MK" variants, which have 3D thrust vectoring. Here's a Su-30 at an airshow (I'm unsure of the exact variant) performing a range of post-stall aerobatics:
https://www.youtube.com/watch?v=ujenrmoeALE
Many of these maneuvers require the pilot to be able to kick his rear end to one side or the other without the aid of aerodynamic control surfaces (such as the post-stall Immelmann, the J-turn, the Super Cobra which basically stands the jet on its tail in mid-air, etc) and thus could not be performed, at least not to the same degree, by an aircraft like the F-22. The utility of such maneuvers in aerial combat is unknown and probably low (standing still in mid-air is more likely to get you shot down than to provide any tactical advantage), which is one reason why full 3D vectoring hasn't been added to U.S. fighters (there was some talk about applying the systems seen on the F-15 ACTIVE and F-16 VISTA to combat planes, but nothing serious ever came of it, and most of those airframes are now slated for retirement).
Answer: An aircraft always needs "3D manoeuverability" (pitch, yaw, roll). Whether you use TVC to perform one, two or all three functions, exclusively, or in combination with aerodynamic control surfaces is a matter of design choices and optimization.
The choice truly depends on what are the requirements of the aircraft in question. Note that TVC in itself is not necessarily "better" than conventional control surfaces on the wing and/or tailplanes.

Aerodynamic control surfaces are very efficient (with enough speed), but take some space and induce loads in the airframe. Ailerons on a wing take space that could be used for flaps. Tailplanes are a pure cost of weight and drag that you pay for maneuverability (and stability).
TVC costs a lot of weight and complexity, but in turn has little to no direct penalty on drag. However, note that it has a rather limited efficiency (which is directly tied to the thrust of the aircraft -- which is not so good: ideally you want thrust and attitude control to be independent).

Maneuverability always has a cost. So the question really is: For a particular aircraft configuration, and for a particular requirement of maneuverability (in pitch, yaw, roll), and for a particular combination of optimization criteria (minimize weight, drag, costs, complexity,...): What is the combination of aerodynamic surfaces and TVC (and other means) that meets the requirement while minimizing the criteria?
Comment: (This does not answer the question) However, what is the added bonus of the third dimensionality of TVC over 2d? What is the combat use case for more maneuverability in yaw? Modern fighters change direction of flight by roll and pitch (roll until you can pull up into the new direction), not generally by yawing. This question is not TVC vs non-TVC, but 2d TVC vs 3d TVC.
Comment: Oh, I heartily agree with what you are saying. What I am saying is you did not answer the question(s) asked. Either the title, or the body... I can't up-vote you as is. (hint hint)
Comment: @CGCampbell, I think this is just another way of looking at the question. There is always a need for some amount of yaw control, that might or might not be related to combat. My point is that whether you should implement it with 3D TVC (with its cost in weight & complexity) or with larger rudders (with their cost of drag) is a matter of optimization of the configuration.


ECDH and Forward Secrecy

Question: I just read about ECDH and while getting a overview over the process, I noticed that this key exchange method does neither provide any forward secrecy, nor does it protect against replay-attacks, because the shared secret will be the same for each session. Are there any common methods that extend ECDH to support these security features?
Answer: To get Perfect Forward Secrecy, you have to use ephemeral keys.
With static Diffie-Hellman (elliptic curve or not, that's not the issue), Alice and Bob both own a DH key pair: Alice's private key is a, public key is aG (elliptic curve notation, G is the conventional "base point" for the curve); Bob's private key is b, public key is bG. When Alice and Bob want to talk to each other, they do the DH thing, which means that they end up with the shared secret value abG. They always have this exact shared secret. If an attacker manages to steals Alice's private key (a), then he can recompute the shared secret, and thus decrypt all past and future conversations between Alice and Bob.
Ephemeral Diffie-Hellman is about generating DH key pairs "on the fly" and not recording private keys anywhere (the private keys are kept in RAM only, and for the duration of the conversation only). Never being recorded ought to make these private keys immune from ulterior theft; that's where PFS comes from. This is used in SSL/TLS with the "DHE" (and "ECDHE") cipher suites: the server owns a private/public key pair, with the public key being in a certificate, and fit for signatures (e.g. that key pair is of type RSA or DSA). When a client connects, both client and server generates new DH key pairs; the server signs his newly generated DH public key with its signature key (the client verifies that signature and validates the server certificate). The key which is actually used to encrypt the data is the one derived from the Diffie-Hellman algorithm.
With DHE cipher suites, should the server's private key be stolen, then the thief only gains the power to compute forged signatures. The thief may then impersonate the server and endanger future communications by running a Man-in-the-Middle attack, but past connections were encrypted with regards to DH keys which have long been lost, and thus won't be decrypted by the attacker. That's PFS.
Comment: *This is used in SSL/TLS with the "DHE" (and "ECDHE") cipher suites* - Do the DHE/ECDHE ciphers mean "PFS, always", or are they required but not sufficient - i.e. PFS is an option on top of those ciphers? I keep finding texts like yours saying PFS *requires* ephemeral key exchange, and then the rest of the text implies that ephemeral key exchange *is* PFS...
Comment: @TessellatingHeckler  DHE and ECDHE are a form of key exchange, allowing two devices to exchange a secret key over a public network where people are assumed to be eavesdropping. Once the key is exchange both parties can save the key and use it in further sessions. The ephemeral bit is the two parties do not save the key. Instead for future connections they use DHE and ECDHE to set up a new secret key to use just for that session. Past session keys are deleted, not stored and reused.

ECDH and Forward Secrecy


Does amirah L'akum apply to robots?

Question: Can you ask/instruct a robot on shabbos to perform melacha on your behalf? Would this fall under the same category as amirah l'akum?
Comment: How is this different from using a timer or pushing a button?
Comment: @nikmasi How is speaking to the robot to make it do something any different from pressing buttons to make it do something?
Comment: what @DoubleAA said. If we really want to go sci-fi, the question could spill out into "is a sentient android considered human for the purposes of agency in the Torah". It must be Friday.
Comment: Related and possible duplicate: http://judaism.stackexchange.com/questions/10358/
Comment: @msh210 I agree, though I support having them in the same question, as the second is potentially a detail of the first.
Comment: @GershonGold I hope it's waterproof. There's no way it was borne of a Jewish mother, so you must have toveled it. The question is, did you say an *al tevilat keilim*, or did it say an *al hatevila*?
Comment: @HodofHod don't see how that's duplicative.  i'm talking about actually instructing it on shabbos
Comment: Wouldn't it be awesome if the title question meant: May a Jewish robot ask a gentile to perform Melachah on Shabbath? #PurimTorah
Comment: The two questions may have different answers.
Comment: @IsaacMoses, yes, I didn't mean otherwise.
Comment: Hey! My robot is Jewish!
Comment: @yitznewton see also http://judaism.stackexchange.com/q/7083/2 and http://judaism.stackexchange.com/q/6008/2
Comment: Ah. I'm sorry, I missed that somehow. Thanks for pointing that out
Comment: @GershonGold cf. http://www.shabot6000.com/p/about.html
Answer:
Rabbi Feinstein writes (Iggerot Moshe, Orach Chaim 4:60) that use of timers to automatically regulate machines to perform work forbidden to Jews on Shabbat is generally forbidden, with the exception of turning on and off lights. He believes that use of timers would severely disrupt the Shabbat atmosphere, since all of one's work could be performed by machines. Rabbi Feinstein asserts that just as the Sages did not want, and therefore forbade our asking, non-Jews to perform work on our behalf on Shabbat for fear that this would disrupt the Shabbat atmosphere (see Rambam, Hilchot Shabbat 6:1) so too the Sages would not want machines to do work on our behalf during Shabbat. Rabbi Feinstein appears to be the lone authority to adopt this approach. 1

The consensus of authorities permits setting timers before Shabbat. It is similarly permissible to allow a website to sell goods on one's behalf on Shabbat.2
Apparently the consensus is that causing machines to work for us on Shabbat is not under the prohibition of amirah l'akum (instructing Gentiles). However, the use of a robot on Shabbat may still be forbidden for other reasons. For example, if it employs a microphone to listen for instructions, there are cases when use of a microphone is allowed, such as in hearing aids (Shemirat Shabbat Kehilchato, vol. 1, 34), and other cases in which it is forbidden, such as for recording or amplifying a performance (ibid.  vol. 1, 28).
Answer: Robots exist now that can act based on voice instructions. You can't tell such a robot to do melacha for you just like you can't indirectly cause any melacha. Additionally, we normally assume using electric devices is assur, and you are directly activating to one.
Ignoring the electric issue, what if the robots developed more advanced AI's so it was a separate agent which made your act of speaking less directly connected to the action it performed?
The gemara states one can acquire an animal by calling it to you (so it walks 4 amos), but not an eved, since it comes on it own free will. Assumably, a robot will be more like an animal since it is unlikely to have human-like free will. If the case by kinyan is parallel to shabbos, it should be assur to cause (through speech) animals or robots to do melacha on shabbos.
Also, it would definitely go against the spirit of shabbos, but probably is not included in amirah l'akum.
Comment: Are you suggesting that the robot would do a melacha for you on a gramma theory (i.e. indirectly)?  Perhaps I could accept that on a yom tov, but on Shabbos?  Under that theory, could I buy a "clapper" device for my lights and turn them on and off indirectly by clapping my hands?  I would think that machines, robots included, are limited to the same extent as an eved with regard to performing melachas on Shabbos.  Also, I don't think that you can compare kinyan with an animal to melacha since the Torah commands us to rest our animals on Shabbos.
Answer: Robots have no free will (just like animals) and I remember seeing a Teshuva which says you can't tell animals to do Melacha for you on Shabbat.
Comment: A teshuva? How about [a pasuk](http://he.wikisource.org/wiki/%D7%A9%D7%9E%D7%95%D7%AA_%D7%9B_%D7%98)?
Comment: Oops! There was some special exception in the Teshuva that made it special.

Does amirah L'akum apply to robots?


Why did the French sell Louisiana?

Question: Why did an imperialistic country like France (at that time) sell a territory so large for so cheap? Was it an important region at the time? I heard that the port of New Orleans was particularly valuable. Even if at that time maybe it wasn't so useful, look at it now!
Comment: Quick answer: Napoleon wanted money to fund his European conquest. I'll answer below with some research/sources later!
Comment: Second to that, Napoleon knew that there was no way he could defend it if America decided to take it by force.
Comment: @hermann Where have you heard that?  It doesn't sound plausible.
Comment: Well considering that the French had just lost Haiti, couldn't get Florida officially and continual war with England they probably needed more money to keep fighting.  I'd have to look at my various history books but I recall this one being a multi-pronged issues.
Comment: I have heard he tried to trade Louisiana for Iceland.
Comment: I think it was just something my history teacher said to the class 20 years ago. Although I'm not sure.
Answer: The sale of Louisiana was a FIRE SALE for France, and specifically, its self-appointed ruler, Napoleon Bonaparte, for these reasons:
1) France had gotten "burned" with her earlier misadventures in North America. The French and Indian war cost her Canada and all of her other possessions on the east bank of the Mississippi. (She had managed to save "Louisiana" by "parking" it with Spain in 1763, then taking it back in 1803.) France was being "burned" again by a(n ultimately successful) slave revolt in Haiti that cost the life of Napoleon's brother in law.
2) Bonaparte was engaged in a war with Britain, and needed money for that war. If he didn't win it, there would be no "tomorrow," at least for him. (He spent is last days as a British prisoner on St. Helena island.)
3) New Orleans was far more valuable to the United States (which had settled half a continent) than to France, which had few settlements nearby. It also threatened to be a focal point of Franco-American hostilities, something Napoleon did not want. Instead, the sale generated "goodwill" that caused America to favor French interests over British interests, ultimately ending up with France and the United States fighting a common enemy beginning in 1812.
Here's what Jefferson wrote to Robert Livingston about the third point:

There is on the globe one single spot, the possessor of which is our
  natural and habitual enemy. It is New Orleans, through which the
  produce of three-eighths of our territory must pass to market, and
  from its fertility it will ere long yield more than half of our whole
  produce and contain more than half our inhabitants. France placing
  herself in that door ...From that moment we must marry ourselves to
  the British fleet and nation.
Comment: the purchase price hardly covered his expenses for that entire period.
Comment: Exactly. IT was deemed a waste of time/effort to try to conquer the Americas as well (though they did heavily consider it.) It was just seen as impractical at that time. The idea was that if they could take Europe, *then* they could go and take the Americas.
Comment: @Tom Au The sad part of this deal is of course that Napoleon could go on devastating most of continental Europe for another decade.
Answer: An important factor was the health of Napoleon's troops. I forget the numbers but Napoleon sent around 50,000 troops out to Haiti and they were devastated by yellow fever.  New Orleans was also a hot-bed of yellow fever at the time.
Comment: If I remember right, the troops sent to Haiti were supposed to continue on once they put down the Haitian revolt.  Since the failed, they never made it to Louisiana.

Why did the French sell Louisiana?


Why is the dipole moment of acetone higher than ethanol?

Question: It is true that acetone is less polar than ethanol.
I thought the dipole moment is proportional to polarity, and if so, the dipole moment of acetone should be lower than ethanol.
But the dipole moment of acetone is higher than ethanol.
Why is it higher?
Comment: Regarding your statement about differences in polarity, did you consider differences in hydrogen bonding capabilities?
Comment: I change comment because I see your point better. You are rather asking why ethanol is more polar than acetone instead of why acetone has higher dipole moment. . It is not the same question. But you got the answer.
Answer: Dipole moment is just one of aspects of solvent polarity, as is well known in HPLC separation  analytical technique where the following effects take part:
Dipole moment interaction, permanent and induced
The above for the whole molecule and for particular bonds
Electron pair donor
Electron pair acceptor (including $\ce{H+}$ donation)
Depending on solute molecules specifics, the solvent polarity order is variable, as various molecules have different responses to above interactions.
See also Using solvent triangle in HPLC
Answer: The bond dipole μ is given by:
$ \mu =\delta \,d$.
The bond dipole is modeled as +δ — δ- with a distance d between the partial charges +δ and δ-. It is a vector, parallel to the bond axis, pointing from minus to plus, as is conventional for electric dipole moment vectors.
In your case, acetone has a higher dipole moment than ethanol because it has a carbonyl group more towards the center and thus acetone has lesser boiling point than ethanol.
The definition is from Wikipedia, : https://en.m.wikipedia.org/wiki/Bond_dipole_moment
EDIT : Alcohol hydrogen bonding is the major effect here, as in the case of water. (by @Poutnik)
Thanks for the edit, @MathewMahindaratne
Think for yourself
Comment: @ShishirMaharana Note that every question and answer has dedicated [edit history](https://chemistry.stackexchange.com/posts/118562/revisions) visible not just to you. Correcting the mistake which another user helped you to discover and then suggest to "*read carefully*" isn't polite and constructive at all. If there were a flaw in my answer, I would rather be grateful and seek other means to improve my answer instead.
Comment: Acetone has 3 carbons, ethanol 2 carbons. Major effect is alcohol hydrogen bonding, similar to water.
Comment: Who said acetone has higher boiling point than ethanol?
Comment: Thanks for paying attention though @andselisk. I am very grateful to your noble deed. I respect you to the highest degree sir. Thanks to all the advisors who helped me edit this answer! Thanks to Chemistry Stack Exchange! All hail Chemistry Stack Exchange! rofl!!! :)
Comment: Read carefully.
Comment: I know that! I meant read again carefully!
Comment: That is why, I first acknowledged Poutnik & then MathewMahindaratne, who made changes in my answer so that it be helpful to our Chemistry SE community!


How long will a keg keep?

Question: We're brewing faster than we can drink. Right now I've got 3 kegs on tap, 1 (primed) keg sitting in the garage (very cold), and 9 carboys ready to be kegged. My question is this -- how long will a primed keg last? Could I keg a beer, purge O2, pressurize with CO2, put it in storage and then put it on tap in 3, 6 or 9 months? If so, should I keep the keg cold? Or does that not matter? Any advice would be great.
Answer: If the keg is properly sealed and stored cool, it'll last for a long time. The real issue, if you wind up storing it for months, is how well the beer style itself can age. If it's a barleywine it can age for a long time, but other styles won't hold up so well.
Comment: The question is more about the beer, and a little about the packaging. Mind your sanitization, purge the headspace and the beer will keep.
Answer: I'll tell you the same thing I told PJ:
Drink More
Answer: I figure that a beer that is kegged and purged of O2 and stored cool (<60°F) will last for up to a year without serious flaws. However, as Darknova said, the styles will change as they age. Usually for the better but that would depend on your taste. I almost never drink any of my beers until they are 2-3 months old. Not because I'm disciplined about aging but like you I always have a backlog to work through.

How long will a keg keep?