Scriptural reference in Hinduism about shortness of human lives

Question: Many religions says that human life is short. Humans are temporary and running behind wealth is waste of time. Are there scriptural evidences in Hinduism saying  that human lives are short?
Answer: The Vedas are full of life and joy. They contain the idea of living hundred years. Atharva Veda, Khanda 19, Hymn 67 pray for living 100 years.

जीवेम शरदः शतम्
A hundred autumns may we live.

Also Vedas have many hymns for obtaining long life and wealth. But short life span of human is discussed in some Puranas especially in the age of Kali.
Shrimada Bhagavatam, 12th Canto, 2nd Chapter talks about the degradation of human values, increase of materialism and shortening of human lifespan in Kaliyuga.

tataś cānu-dinaṁ dharmaḥ
  satyaṁ śaucaṁ kṣamā dayā
  kālena balinā rājan
  naṅkṣyaty āyur balaṁ smṛtiḥ (1)
Then, O King, religion, truthfulness, cleanliness, tolerance, mercy, duration of life, physical strength and memory will all diminish day by day because of the powerful influence of the Age of Kali.
vittam eva kalau nṝṇāṁ
  janmācāra-guṇodayaḥ
  dharma-nyāya-vyavasthāyāṁ
  kāraṇaṁ balam eva hi (2)
In Kali-yuga, wealth alone will be considered the sign of a man's good birth, proper behavior and fine qualities. And law and justice will be applied only on the basis of one's power.
triṁśad viṁśati varṣāṇi
  paramāyuḥ kalau nṛṇām (11)
The maximum duration of life for human beings in Kali-yuga will become fifty years.

Same thing has been said in Vishnu Purana, Book 6, Chapter 1.

He who gives away much money will be the master of men; and family descent will no longer be a title of supremacy. Accumulated treasures will be expended on (ostentatious) dwellings. The minds of men will be wholly occupied in acquiring wealth; and wealth will be spent solely on selfish gratifications.
Oppressed by famine and taxation, men will desert their native lands, and go to those countries which are fit for coarser grains. The path of the Vedas being obliterated, and men having deviated into heresy, iniquity will flourish, and the duration of life will therefore decrease. In consequence of horrible penances not enjoined by scripture, and of the vices of the rulers, children will die in their infancy. Women will bear children at the age of five, six, or seven years; and men beget them when they are eight, nine, or ten. A man will be grey when he is twelve; and no one will exceed twenty years of life.
Comment: "men will desert their native lands, and go to those countries which are fit for coarser grains " - very true, many of us are in Western countries - USA, UK etc. where staple food is wheat/corn/maize.
Comment: @ChinmaySarupria It is about future.
Comment: "The maximum duration of life for human beings in Kali-yuga will become fifty years" This is obviously incorrect.
Comment: @ChinmaySarupria, why is it incorrect ? It WILL be 50 years as Kali progresses.. lifespan will slowly decrease.. thousand years ago, people lived easily upto 80, 90, some even 100. nowadays, it is 60,70.
Comment: @ram It says "maximum life span will be 50 years", if it's maximum no one should live in excess of 50 years which proves that part of Srimad Bhagavatam is interpolation.
Answer: Humans are temporary and running behind wealth is waste of time. Are there scriptural evidences ?
Yes we can find the scriptural reference of  Humans are temporary and running behind wealth is waste of time and shortness of human life in our ancient Upanishads.
In Katha-Upanishad  there is famous story Nachiketa and Yama , where Nachiketa goes to Yam-Loka , satisfied with him Yama grant Nachiketa 3 boons.Then Nachiketa  and asks one  questions to Yama ( the death god.)
When **Nachiketa asks Yama about what happens after death.**Yama says to him that "O child ask anything for of material nature women ,wealth ,power ,long life ,kingship of earth , vehicles ,gold ,horses.
Then Nachiketa    says this to Yama -:

श्वोभावा मर्त्यस्य यदन्तकैतत्सर्वेंद्रियाणां जरयंति तेजः ।  अपि
सर्वं जीवितमल्पमेव तवैव वाहास्तव नृत्यगीते ॥ २६ ॥
śvobhāvā martyasya yadantakaitatsarveṃdriyāṇāṃ jarayaṃti tejaḥ |
api sarvaṃ jīvitamalpameva tavaiva vāhāstava nṛtyagīte || 26 ||
(Nachikêtas says) Ephemeral these; Oh Death, these tend to the decay
of the fire (vigour) of all the senses in man. Even the longest life
is, indeed, short. Thine alone be the chariots, the dance and music.

Here Nachiketa is refusing all the material pleasures offered to him by Yama in substitute of asking questions about death. But wise Nachiketa says ……Life is short …And all this pleasures are temporary.
And this is Shankara's Commentary:
.—Though thus tempted, Nachikêtas unagitated like a large lake, said: svôbhâvah, enjoyments whose existence the next day is a matter of doubt; the enjoyments enumerated by you are ephemeral; again. Oh Death, they tend to the decline of the vigour of all the organs of man. These nymphs and other enjoyments only tend to harm, because they destroy virtue, strength, intellect, vigour, fame and the rest. As for the longevity that you will give me, hear me on that point. All life, even that of Brahmais, indeed, short. What need be said of our longevity. Therefore, keep the chariots, etc., for thyself alone, as also the dance and music.
also shortening of human life during kali-Yuga also is described in Ling-Purana –Purva Bhaga –Chapter 40 – Extent of Caturyugas. – Page 153 –Shloka 33

प्रनष्टचेष्टना: पुंसो मुक्तकेशाच्श्र शूलिन: |  जना षोडषवर्षाच्श्र
प्रजायंते युगाक्षये ||33||
They would be unable to value the things correctly. They shall have
disheveled hair.
During the time of decline of the Kali-Yuga the people will be born with only sixteen years of age.
Comment: IMO, OP is not talking about life span in Kali yuga or the gradual decline of Ayu with the progress of Yugas, but in general whether scriptures mention that human lifespan is short and many things are to be done etc..
Comment: Then Bhagavata seems to be saying that Humans will live for 50 years??
Comment: Hindu  SB Shloka is saying 20 OR 30. But it should not be taken as 20+30 , some translations are adding the both. But In gita press  its give 20 or 30.
Answer: Many verses said by Lord Shiva in KulArnava Tantram's (which is a ShAkta Agama) Ullasa 1 can be used to answer this question.
He discusses the shortness of human life ( or the shortage of years we have to accomplish our goals) in great details in that chapter.
I am posting only four such verses here:
Even the full life span of 100 years is not sufficient

Satam jivitamatyalpam nidrA swyAdardhshArini |
  VAlyarogajarAdukkhairardham tadapi nisphalam ||
........
The lifespan of even 100 years (which is also known as parama Ayu) is too short.  Half of which is
  taken by sleep. And, the remaining half is rendered fruitless by
  childhood, diseases and grief.

The temporary and short-lived nature of wealth, longevity and youth

Sampadah swapnasamkAshA yauvanam kusumopamam | TaricchanchalamAyuscha
  kasya syAjjAnato dhriti ||
..........
Wealth (Sampada) is [illusive] like dreams. Youth (Yauvanam) is like a
  flower [that withers within no time]. Longevity (Ayu) is unstable
  (chanchala) like Vidyut [it comes and goes]. After knowing all that
  how can one still remain patient

Don't waste time thinking about petty matters

Apatyam me kalatram me dhanam me vandhavAscha me |
  Lapantamiti martyam
  hi hanti kAlabriko valAt ||
....
My son; my wife; my wealth; my friends;-  Kala forcefully takes his
  life away who wastes time in thinking like that.

Death (Kala) does not wait for anyone, so better hurry up

Swayah kAryamadya karttabyam purvAnhe chAparAnhikam |
  Na hi pratikshate mrityuh kritam vAhasya na vA kritam ||
..........
What is supposed to be done tomorrow has to be done today only. What
  is supposed to be done in the afternoon should be done in the morning.
   Mrityu (or death) does not wait thinking what a person has done what he has
  yet to do.
KulArnava Tantram's Chapter 1 verses

So, that's why we should be ever agile to make life's every moment count.
This is one of the essences of Lord Shiva's discourses found in the aforementioned chapter.
Answer: Scriptures mention the age of humans as 100 years.
Isha Upanishad, Verse 2:

कुर्वन्नेवेह कर्माणि जिजीविषेत् सतं समाः
एवं त्वयि नान्यथेतोऽस्ति न कर्म लिप्यते नरे
Meaning: In the world, one should desire to live a hundred years, but only by performing actions. Thus, and in no other way, can man be free from the taint of actions.

Vedas say the same thing:

Shatāyur vai purushah
Man lives for 100 years.

Adi Shankara also says in his commentary:

tavad hi purushashya paramayuh nirupitam
that long, verily, has been determined to be the length of human life.

In the Brahmacharya ceremony, the boy is blessed with the words:

May you live a hundred years

Puranas might say that human lifespan is different or decreases but because Vedas and Upanishads clearly say that human life is 100 years, Puranas should be rejected in this case.
Comment: Who is asking here about what is the lifespan of a human being? I think u misunderstood the Q.
Comment: @Rickross Question asks will lifespan decrease but it doesn't and that's what I've said in my answer that lifespan is 100 years, no increase no decrease.
Comment: OP is asking (as far as i have understood) " Is life span of even 100 years  inadequate? whereas u answered the Q " What is the lifespan of a human being? Is it 100 or 1000 or even more years?"
Answer:
The rigvedic seers prayed for long life of 100 autumns, large (male)
  progeny who will be brave (suveerAH) and, of course, for wealth, cows
  and so on. In that respect, I feel that at least our earliest Veda did
  not consider life in this world as short or chasing material
  prosperity as bad. There could be isolated instances contrary to the
  above, in the vast ocean that is rigveda; scholarly members may come
  forward to correct my impression as above.
My impression is that it was the Upanishadic phase of the vedas which
  started this illusoriness of the worldly life, chasing material wealth
  as wasting your life, etc. May be, contemplation about human life
  might have revealed to the Upanishadic sages/seers/rishis, the
  impermanence of the worldly life and the human intellect's
  inability/impossibility of knowing about our past (before birth) or
  our future after death. Given this background, human existence will
  appear to be transcient and meaningless, so to say. The Upanishads,
  therefore, give us a mixed picture — following the veda and diverging
  from the veda. It is the commonly held belief that Adishankara gave
  his advaita philosophy as the gist of all the Upanishadic advancements
  in philosophical thoughts and so this was called as Vedanta (end of
  the Veda/s).  एकं सद्विप्रा नैव जानन्ति ।
Comment: Mention the source from where you have cited the text. If this is your words, remove quoting. After fixing flag to remove the citation notice.


Gitlab clone over http fails to authenticate from external network

Question: I have Gitlab 5.2 + Nginx installed on a local machine in my university. Clone over http works for machines that are within the internal network, but trying to clone from a machine on an external network results in an "fatal: Authentication failed" message, even though the exact same credentials are supplied. (I use the same credentials as the ones I use to log in to Gitlab via the web interface)
The Gitlab web interface is accessible from external networks. It is only the clone over http that fails (clone over ssh is not possible because port 22 is blocked)
Here are some lines from the relevant configuration files:
from config/gitlab.yml
host: mydomain
port: 80
https: false

Here are the relevant lines from the ngnix config file
server {
  listen *:80 default_server;         # In most cases *:80 is a good idea
  server_name mydomain;     # e.g., server_name source.example.com;
  root /home/git/gitlab/public;

  # individual nginx logs for this gitlab vhost
  access_log  /var/log/nginx/gitlab_access.log;
  error_log   /var/log/nginx/gitlab_error.log;

  location / {
    # serve static files from defined root folder;.
    # @gitlab is a named location for the upstream fallback, see below
    try_files $uri $uri/index.html $uri.html @gitlab;
  }

  # if a file, which is not found in the root folder is requested,
  # then the proxy pass the request to the upsteam (gitlab unicorn)
  location @gitlab {
    proxy_read_timeout 2000; # https://github.com/gitlabhq/gitlabhq/issues/694
    proxy_connect_timeout 2000; # https://github.com/gitlabhq/gitlabhq/issues/694
    proxy_redirect     off;

    proxy_set_header   X-Forwarded-Proto $scheme;
    proxy_set_header   Host              $http_host;
    proxy_set_header   X-Real-IP         $remote_addr;

    proxy_pass http://gitlab;
  }
}

Note: I have added this line to /etc/hosts: 127.0.0.1 mydomain but it doesn't really help. (based on https://github.com/gitlabhq/gitlabhq/issues/3483#issuecomment-15783597)
Any ideas on what the issue might be/how I might debug this?
Answer: I believe this is fixed in 5.3, so try updating. See:

https://github.com/gitlabhq/gitlabhq/blob/master/CHANGELOG#L41
https://github.com/gitlabhq/gitlabhq/blob/master/config/gitlab.yml.example#L151
Comment: Just to clarify - I don't use LDAP authentication. The weird thing is that git over http actually works from the internal network. It only fails when I try to do it from an external network.


What is a table prefix?

Question: What is a table prefix, and what are their advantages and disadvantages? This is in relation to MySQL.
Comment: Are you referring to a table name prefix such as tblTasks or the schema i.e. dbo.tasks
Comment: A table prefix is a prefix that is added to every tablename, as the name implies.
Answer: This is often used to distinguish different installations of the same script from each other.
For example let´s say you have two Joomla Installations with different content on your server, but only one MySQL Database.
Now, for obvious reasons both Joomla installations can´t share the same database tables, as that would result in both installations displaying the same contents. And that is where the prefix kicks in.
By using different table prefixes you can let Joomla Installation #1 know that it is supposed to use all the table with Prefix JOS_ and Joomla Installation #2 has to use all the tables with the prefix JOS2_
Answer: Tables do not require prefixes.
This is purely up to you.
However, we prefix tables with relation to the MODULES in the application they belong to, just to group the tables more easily.
Answer: Some people advocate tbl or tbl_ (e.g. tbl_MyTable or tblMyTable) whilst others go with a suffix such as MyTable_T.
Personally I avoid the prefixes/suffixes. I may substitute in a View in place of a Table if a schema is changing over time so I don't really distinguish between the two types of object.
The most important thing is that you have your naming guidelines documented within your team and you all stick to the same set of guidelines for consistency.
Answer: In a small amount of cases, such as those where malware scripts have been created to target specific types of sites such as WordPress etc., changing the table prefixes has been useful as an extra security measure.
For example, adding table prefixes obscures common table names making it harder for hackers to access data in your database through SQL injection or other security holes because they will first need to discover what your table names are.
Be sure, however, to look at table prefixes as only a very minor layer of security. It should NOT be your main security method. You should still be taking other more important security measures to prevent SQL injection and other similar threats. For example, depending on how your code is set up it may still be possible for a hacker to run a "show tables" command through SQL injection to get the names of your database tables.
Comment: Security through obscurity is not a security. It's an illusion of security.
Comment: @MariuszJamro Did you even read my answer? Also, not all obscurity is just an illusion of security. For example, I just went on vacation and hid some of my technology somewhere in my house in a very difficult to find place. Could someone eventually figure out where it was? Absolutely. Does it add an extra layer of security? Absolutely. Is it an illusion of security just because it is obscuring it? Absolutely not.
Comment: It's an illusion because you **feel** safer, when you're actually not. In reality it won't stop anyone from reverse engineering your DB structure and figuring out what particular tables actually store/do.
Comment: @MariuszJamro Again, did you even read my answer? I have already addressed your concern in my answer.
Comment: I did and i understand your reasoning. I just find it wrong in context of this question. Table prefixes are not useful for security purposes as you don't get "extra security" by using them. You just make your life harder.
Comment: A few years ago there were various worms going around that would look through vulnerable WordPress sites, and retrieve and manipulate the `wp_users` table. In these cases, those who had used a different prefix were not affected by these worms. And while having a different prefix was a weak security measure, it was a security measure nonetheless. While the best security would have been for the developers of WordPress to completely eliminate all chances of SQL injection, the end users should not assume that this is the case.
Answer: Strange no one mentioned that you also can use table prefixes to use normally reserved keywords as tablenames.
E.g. t_user or t_order are now possible.
Answer: If you have a complicated website and database structure, table prefixes may help prevent naming conflicts in the database.
You often see table prefixes in situations where:

Multiple scripts are being integrated together into one website, and the finished website needs to share data, but the table names would conflict without a prefix unique to each script.
You are adding functionality to a script you acquired, and you want to distinguish between tables native to that script and new tables you are manually creating. That way if you create a new table, it won't conflict with any future updates to the base script, since it has a different table prefix.
You have a hosting plan that only gives you one database and you want to use that database to service multiple scripts. (This isn't recommended for a variety of reasons, but I've seen users do this.)

When you are writing a script from scratch, table prefixes usually aren't necessary since you control all aspects of the database structure. It's when you start integrating multiple scripts together that it becomes useful and sometimes even necessary. It allows you to create unique data views, and join tables, and such between multiple scripts without worrying about naming conflicts in the database.
Answer: It may help to distinguish between tables and views depending on what your naming convention is.
The disadvantage is that you may be limited as far as the name of a table is concerned. Oracle has a limit of 30 characters for this. If you use "Tbl_" as the prefix, you automatically lose 4 characters. That may be a problem.

What is a table prefix?


Does fetchmail support SSL or TLS when using SMTP to forward email?

Question: I am trying to forward emails that are fetched with fetchmail to another SMTP host, which enforces STARTTLS. I could not find a way to enable TLS in fetchmail. Is this possible at all? If so, how?
Answer: It does not appear that fetchmail supports TLS to the SMTP server.  This is normally not a problem, as it usually delivers emails locally.
You can work around this by delivering to a local SMTP server and have it handle the delivery.  If your don't need or want a full service server like exim4 or postfix, you can use a light-weight relay like esmtp or 'msmtp` to deliver the mail.
Comment: Actually your recommendation is what I did. I used `msmtp` to forward the mail. It's a nice tool and supports TLS.


Is VOTE a linking or an action verb?

Question: In the sentence "Brianna was voted the co-captain" is "was voted" a linking or action verb phrase?
I believe it is action and "co-captain" is the direct object (co-captain as a title/position), but it is difficult to explain to students as they view it as Brianna = co-captain.
Comment: Let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/57414/discussion-between-billj-and-araucaria-man).
Answer: If you change the sentence into active you get: They voted Brianna co-captain with the structure verb, direct object, complement to direct object.
This is not the structure of a sentence like "My father is a teacher". So I wouldn't say "voted" is a linking verb.

Is VOTE a linking or an action verb?


Nonparametric bootstrap to construct confidence intervals for Cohen's Kappa Coefficient

Question: I was recently asked to perform nonparametric bootstrap to construct 95% confidence intervals for $\kappa$ using normal approximation, but I'm not sure how to do this. The only data I was given was the table below:
<code>| Clinical trial |
|---------------|----------|----------|
| Meta analysis | Positive | Negative |
| Positive      | 13       | 6        |
| Negative      | 7        | 14       |</code>
 I believe the $\kappa$ that they are referring to in this case is the Cohen's Kappa Coefficient. Can someone please shed some light on this for me?
Comment: I guess the first step is to figure out how to determine the point estimate for kappa for the sample data...
Answer: Original (unwighted) Cohen's kappa
Cohen's kappa is defined as:
$\kappa = 1 - \dfrac{1-p_e}{1-p_o}$
Where $p_e$ and $p_o$ are the expected (due to chance) and observed agreement, respectively. The expression for $p_e$ assumes that the joint probability distribution of positive and negative factors into a product of the marginal probability distributions for the two observers. So,
$p_e = \dfrac{1}{N^2}\sum\limits_{k} n_{k1}n_{k2} = \dfrac{1}{40^2}(20\times 19 + 20\times 21)$, k $\in$ {positive, negative}
$p_o = \dfrac{a_{11} + a_{22}}{a_{11} + a_{22} + a_{12} + a_{21}}= \dfrac{13 + 14}{13 + 14 + 6 + 7}$, in your example.
Now, to bootstrap you need to sample from your distribution with replacement. One way to do this is to make a vector with 13, 14, 6, and 7 elements each of $a_{11}, a_{22}, a_{12},$ and $a_{21}$, respectively (i.e. the length of the vector is 40). Now you sample, say, 1000 vectors of length 40 from that vector with replacement and each time calculate the kappa as above. The 95% bootstrap confidence interval will be the 2.5 and 97.5 percentile of the calculated kappa values.
Weighted Cohen's Kappa
For a weighted kappa use instead (NOTE: not relevant for your $2\times 2$ example):
$\kappa = 1 - \dfrac{\sum_{i,j}\text{w}_{i,j}O_{i,j}}{\sum_{i,j}\text{w}_{i,j}E_{i,j}}$ for i, j $\in$ {the ordinal categories}.
$O_{i,j}$ is just the observed proportions of $a_{i, j}$ in each bootstrap sample and
$E_{i,j}$ is the product of the marginal distributions, e.g.
$E_{1, 1} = \dfrac{(13 + 6)\times (13 + 7)}{40}$, in your example.
Finally, the weight matrix can be chosen arbitrarily but are usually derived as linear or quadratic by:
$w_{i,j} = \dfrac{(i-j)^x}{(N-1)^x}$, with x=1 for linear kappa and x=2 for quadratic kappa.
The linear kappa gives a linearly larger penalty for ordinal categories when the distance of the disagreement increases, and the quadratic kappa gives a smaller penalty for short distances and a larger penalty to large distances, relative to the linear weights.


Was Catholicism chosen by the Roman Empire because of synergies to Roman hierarchy?

Question: I was watching a documentary on the History Channel recently and they mentioned that when the Roman Empire converted to Christianity, they chose Catholicism because of its similarities to the hierarchy of the Roman government of the time. I had never heard that before and am wondering if there is any documented evidence of this being the main reason in their decision.
Comment: Did the History Channel by chance go into detail on what the _other options_ might have been? Or offer any evidence at all beyond their own speculation? This sounds like a Dan Brown plot more than a history dissertation. Either way we can probably answer this, but it would be useful if you could [edit] in a little more detail about exactly what their assertion was in relation to other possibilities.
Comment: Pagan Rome didn't have a hierarchical structure to their society, too?
Comment: @Naeco as the folks at History.SE might advise you, the History channel isn't known for their rigor.  Their intent is to entertain.
Answer: In my catechetical training, and in a biography of Constantine, I learned that the conversion of the Roman Empire was "top down". Constantine converted to Christianity, made Christians equal to those of practitioners of other religions, and lower class Romans found it expedient to adopt the religion of the emperor. The development of the hierarchy of Catholic Church resulted in similarities to the Roman political structures because the Catholic Church deliberately copied those structures because they worked. Romans at first did not convert but later decided to adopt Catholicism as their religion.
Comment: Is it your understanding that the heirarchical nature of the Catholic Church was as a result Constantine's decisions, rather than already being there?  (That is how I understand it, but this is your answer).   IF that is the case, it might be worth spelling that out given what's in the question.  If the question is based on a weak premise, sometimes spelling that out in more detail is helpful.
Answer: Constantine was looking for a model of unity which, because of its internal discipline, the Church appeared to provide. Paganism was disunited, with too many cults, and was far too tolerant to be a model for an autocratic empire. The alternative to Catholic-Orthodox Christianity was Gnostic Christianity, which made a virtue of disunity, refusing even to appoint bishops. Michael Grant says in The Emperor Constantine, page 161:

Apart from his deep emotional involvement, the main reason Constantine favoured Christianity was that he believed that it would encourage unity in the empire.  Unfortunately the Christian faith failed to achieve that aim, due to the dissensions between one Christian group and another.

The Church hierarchy was not entirely similar to that of the Roman Empire as, for example, the Empire had a powerful leader, whereas the Church was led by an assemblage of bishops who had not yet really  defined mechanisms for resolving differences among themselves -- deficiencies that Constantine attempted to resolve by calling the Council of Nicaea.  Constantine had inherited the pagan title of Pontifex Maximus and now saw himself in this role as providing overall leadership for the Christian Church.
Constantine had discovered that in spite of the appearance of internal discipline, the Church  was not united, with just the most recent controversies being Arianism and Donatism, but under his leadership the Church did become relatively unified. It was then able to help Constantine and his successors achieve their aim of managing the unwieldly empire, at least for the remainder of the fourth century.


Conscience in Buddhism

Question: Conscience is described as being the moral sense in which an individual makes decisions. Do Buddhists believe there is a conscience? If so how is it defined
Answer: In Mahayana abhidharma, we speak of the two mental factors that I would think are quiet similar to the "moral conscience" that you allude to. These two might be the same as 'shame' and 'conscience' in MA45. The two are:

Shame (Tib. ngo tsha shes pa)
Embarassement (Tib. khrel yod pa)

Regarding shame, the Compendium of Knowledge says:

Question: What is shame?
Answer: It is an avoidance of misdeeds on
  account of oneself. It has the function of acting as a support for
  effective restraint from misconduct.

An example of shame is to restrain from stealing even when nobody would have known. It is akin to self-respect.
Regarding embarrassment, the Compendium of Knowledge says:

Question: What is embarrassment?
Answer: It is an avoidance of
  misdeeds on account of others. It has the function of just that [i.e.,
  acting as a support for effective restraint from misconduct].

An example of embarrassment is to restrain from stealing by thinking "there is a camera", paying heed to what others would think of our negativity, or thinking "what would my teacher think if he knew?".
Answer: Offcourse conscience plays a vital role in the enlightenment. Following quote from this sutta explains how :

At that time, the World Honored One addressed the bhikṣus: "If a
  bhikṣu has no shame, has no conscience, that will be detrimental to
  his love and reverence. If he has no love or reverence, that will be
  detrimental to his faith. If he has no faith, that will be detrimental
  to right thinking. If he does not have right thinking, that will be
  detrimental to his right mindfulness and right knowledge. If he does
  not have right mindfulness and right knowledge, that will be
  detrimental to guarding his faculties and guarding the precepts, to
  non-regret, to encouragement, to ease, to calm, to happiness, to
  concentration, to seeing according to reality and knowing according to
  reality, to disenchantment, to desirelessness, and to liberation. If
  he does not have liberation, that will be detrimental to having
  Nirvāṇa.
Answer: I think it's understood as:

Compassion -- e.g. "all fear death: so, putting yourself in the place of another, do not kill"
Duty -- giving their due to parents and teachers, family, employers and employees, friends
Karmic results -- knowing that doing bad things, doing things with bad intentions, has bad results (not exactly as a punishment but just as a natural consequence, a law of nature)
Spiritual (or, in Buddhism, mental) development -- becoming less selfish, maybe less greedy
Presence or absence of "regret" or remorse (kukkucca or vippaṭisāra) -- an absence of remorse is not just an end in itself (because it's unpleasant to experience), but a necessary prerequisite to joy, tranquillity, concentration (AN 11.1).
Mindfulness -- i.e. remembering what you're supposed to remember

The concerns or topic of conscience might therefore span all three parts of the threefold training -- i.e. "virtue", but also "concentration" and "wisdom".
Answer: Conscience or decision making falls under Sankhara(mental formation) aspect of an experience(an instance of the five aggregates). It is accompanied by Vinnana(consciousness). Conscience is caused, impermanent and non-self; same as the rest of the five aggregates.
Answer: Yes, conscience is known in Buddhism as "hiri-ottappa" (literally "shame-disgrace", used as one word) and plays a fairly important role, especially in the early stages of the Path as well as for lay people.
Bhikkhu Bodhi explains:

Hiri is an innate sense of shame over moral transgression; ottappa is moral dread, fear of the results of wrongdoing
Hiri, the sense of shame, has an internal reference; it is rooted in self-respect and induces us to shrink from wrongdoing out of a feeling of personal honor. Ottappa, fear of wrongdoing, has an external orientation. It is the voice of conscience that warns us of the dire consequences of moral transgression: blame and punishment by others, the painful kammic results of evil deeds, the impediment to our desire for liberation from suffering. Acariya Buddhaghosa illustrates the difference between the two with the simile of an iron rod smeared with excrement at one end and heated to a glow at the other end: hiri is like one's disgust at grabbing the rod in the place where it is smeared with excrement, ottappa is like one's fear of grabbing it in the place where it is red hot.

You can read more about this in The Guardians of the World article by Bhikkhu Bodhi.
Answer: According to the conscience once karma decides, as Lord Buddha sermon..When someone does a good or bad deed,it'll keep in his/her mind,Here  Conscience gives the decision whether it's good or bad before keep it in once mind..anyone can lie or show this's correct/wrong..But conscience know the reality,anyone can't cheat his own conscience..
The karma gathered like this gives result when suitable time comes,So we can tell that so called conscience is also a part of our mind which decides whether our acts are good deeds or sins

Conscience in Buddhism


Who owns The Lone Ranger these days?

Question: News has it that Universal Studios is working on the next Green Hornet reboot, The Green Hornet and Kato.  What about Britt Reid's great uncle, the Lone Ranger?  Have the film rights to him reverted away from Disney and Jerry Bruckheimer by now?  If so, is it known where they are at?
Answer: Universal Pictures
From Wikipedia

Ownership
From its inception, George W. Trendle had legal ownership of the Lone Ranger and characters associated with the Lone Ranger through his company, The Lone Ranger, Inc. Trendle sold The Lone Ranger, Inc. to oil man and film producer Jack Wrather in 1954 for $3 million. After Wrather died in 1984, his widow, Bonita Granville, sold the Wrather Productions properties to Southbrook International Television Co. in 1985 for $10 million Broadway Video acquired the rights in 1994. Classic Media acquired the rights in 2000. DreamWorks Animation acquired Classic Media in 2012 and renamed the division DreamWorks Classics, which was acquired by NBCUniversal in 2016 for $3.8 billion. Its Universal Pictures unit currently has the rights to the Lone Ranger.

Who owns The Lone Ranger these days?


When do you use the passive form?

Question: I heard somebody say "In normal conversation, most native speakers do not go out of their way to use the passive, as student textbooks might lead you to believe we do."
Then when do you 'native speakers' use the passive form specifically?
Comment: I don't think about it whatsoever. In other words, during a conversation, I never think to myself, "Now's a good time to use the passive voice," or, "This would be a good time to switch to the active voice." I just talk.
Comment: I'm not a native speaker, but from what I've seen, it depends whether you want a certain word to be subject of the sentence or speech so that it fits with the topic and flow of the text/speech. The choice is often made by stylistic reasons.
Answer: The passive voice is used when the agent of the action is unimportant or unknown, or when we want to de-emphasise the agent.

"A jewellery shop was robbed last night." - we don't know who robbed
  it.
"Eggs were thrown at John Prescott." - we don't know who threw the
  eggs.
"10mg of copper sulphate was added to the hydrochloric acid solution."
  - it isn't important who added the copper sulphate.
"Mistakes were made" - we don't want to talk about who made the
  mistakes.

News reporting and scientific writing are the most common places to find the passive voice.
It's also used when we want to emphasise the agent of the action by putting it at the end of the sentence instead of the beginning.  The normal English sentence structure is subject - verb - object but by using the passive voice we can change the order the subject and the object.

"Christopher Columbus discovered America"
  versus
  "America was discovered by Christopher Columbus."
"A reindeer ran over my grandmother"
  versus
  "My grandmother was run over by a reindeer."
Answer: The most common usage of the passive voice if they either don't know, or don't want to say, who or what is the subject of the sentence.
Let's suppose somebody stole my bicycle. I say to my friends:

Some jerk stole my bike yesterday!

I go to the police station to report the crime, and I say:

My bicycle was stolen yesterday.

You can also use it to move the important part of the sentence to the beginning. So I would say to a friend:

A guy from DEFRA handed out the prizes.

but a journalist reporting the event would think about writing:

A spokesman from the Department of the Environment, Food and Rural Affairs presented the awards.

and then change it to:

The awards were presented by a spokesman from the Department of the Environment, Food and Rural Affairs.
Comment: The *end* of the sentence is where we put new and important information. We use passives to put the boring info at the beginning so that the important info comes at the end! (see @ssav's answer)

When do you use the passive form?


Where can I find some fun Excel sample data to download?

Question: Are there any web applications out there that offer free Excel sample data utilizing fun topics like perhaps Star Wars characters?
Comment: What do you mean by "Excel sample data"?  [Kaggle](https://www.kaggle.com/) has many datasets made available for data science projects (including some Star Wars-related ones).
Comment: @BrenBarn, can those datasets be imported into an Excel spreadsheet?
Comment: Many of them are CSV files so yes, you could load them into a spreadsheet.
Comment: @BrenBarn, excellent! Please post as answer, I will check it out this weekend.
Answer: Kaggle is a website for data science competitions.  They have many datasets available for use.  You generally must create a Kaggle account to get the data, but doing so is free.  Many of the datasets are available as CSV files, which you could load into Excel.  They're not designed for use in Excel, though, but rather for use with machine-learning libraries and programming tools (e.g., Scikit Learn), so some may be difficult to use in Excel depending on the nature of the data.  There are a few Star Wars related datasets, including for instance this one that has dialogue from the movies.


What does "stagger" mean in Overwatch?

Question: I frequently hear Overwatch players and commentators using the verb "stagger". What does this term refer to, and what is its significance?
Comment: (Despite the title, this is _not_ a dupe of the related question titled "What does 'stagger' mean?" -- that question is specific to Skyrim.)
Answer: Staggering refers to respawn timers. If all enemy players die at about the same time, they will respawn and be regrouped at about the same time. But if you let a baby d.va live for a few extra seconds, that delays their next push by that much
Comment: It's interesting to note that Overwatch didn't implement Team Fortress 2's spawning system which is intentionally designed to spawn players together by varying spawns by up to 5 seconds.  i.e. if you spawn 3-4 seconds after another player, you're likely to be spawned together.
Comment: I suppose it makes sense in a more competitive game such as Overwatch, where literally a single second can be the difference between extending Overtime or not. "Not" arbitrarily adjusting timers keeps things "fair" as there is no rounding up or down which "might" benefit or hurt teams "depending". Instead it just "is what it is".

What does "stagger" mean in Overwatch?


What does pronoun "it" refer to?

Question: "A container had a line with a number beside it for every hour."
Comment: Literature interpretation/criticism is off topic unless a specific source of concern (*why you asked the question*) is clearly identified.
Answer: When determining the antecedent of a pronoun, the most recent noun should be examined first, and then you work your way backwards.
In the sentence above, there are three nouns.  Working backwards, they should be analyzed as follows:

number.  That noun is at the end of a prepositional phrase that logically says "I'm not actually the antecedent."
line.  This is the most likely contender - a number beside the line makes sense, but it's not iron clad.
Container.  I can't rule it out, but a number beside a container makes a lot less sense than a number next to a line. I'd go with #2.

What does pronoun "it" refer to?


Lie groups and orthogonal group

Question: Are orthogonal groups are lie groups? I think parameter space points corresponds to  elements with determinant -1 break analytic property of  lie groups , what is the general condition to check a group is lie group or not ?
Comment: An analogy: would you consider the nonzero real numbers $\mathbf R^\times$ *not* to be a Lie group because the sign function is $-1$ on negative numbers? Lie groups do not have to be connected.
Answer: Yes, orthogonal groups are Lie groups. Since, $O(n,\mathbb R)$ consists of two copoes of $SO(n,\mathbb R)$, if $SO(n,\mathbb R)$ is a Lie group, then so is $O(n,\mathbb R)$.
Answer: Orthogonal groups can be defined over arbitrary fields $K$ as the subgroup of the general linear group $GL_n(K)$ given by
$$
 \operatorname {O} (n,K)=\left\{Q\in \operatorname {GL} (n,K)\;\left|\;Q^{\mathsf {T}}Q=QQ^{\mathsf {T}}=I\right.\right\}.
$$
Now for example, for a finite field we obtain a finite group, which is  also a compact discrete Lie group of dimension $0$.
Real orthogonal groups are real linear groups and hence real Lie groups.

Lie groups and orthogonal group


Number of CPU cores versus frequency of cores in Qemu/Virtualbox

Question: I plan to build a workstation mainly for running virtual machines. There will be dozens of virtual machines and they do not execute computationally expensive tasks. I will use mainly Qemu(with KVM support) as an hypervisor. I am aware that I need to pick a CPU with VT-x/AMD-v support and I would benefit from Hyper-threading, but how do less high-frequency cores compare to more lower-frequency cores in hypervisor environment? Let's say for example quad-core Core i7-4790K overclocked to 5GHz versus octa-core Xeon E5-1428L v3 where all eight cores run at 2GHz. If any additional information is required then please ask.
Answer: You can look to benchmark comparison
http://www.cpubenchmark.net/compare.php?cmp[]=2116&cmp[]=2275
I have the same CPU i7. But not with KVM. I have installed SmartOS (ZFS Raid 10) with FIFO-project. If you have any questions, i can answer.
But i can't post comments, sorry. There integrated
Answer: If your VMs are computationally expensive, then faster /  higher frequency cores are better, especially if the software you are running is not written to take advantage of multiple cores to perform calculations in parallel - multi-core or multi-processor is of no benefit if the software can not make use of them.
If your computationally-heavy software is written for parallel computation, then obviously the more cores AND the faster each core, the better.
If your VMs are computationally "light", then the more cores you have, the better even if each individual core is slower.  Higher core frequencies will be of little or no benefit if the software you are running doesn't actually need it, if it spends most of its time idling.  More cores, however, will be of benefit in this case because each core won't have to switch context as often to switch between VMs - the ideal situation would be around one core per VM...or, at least, as close to 1:1 as possible.
If most of the VMs are mostly idle most of the time, then higher ratios of 2 or 3 or more VMs per core would be perfectly viable.  Economising like that is part of the point of virtualisation of machines after all - less rack space, less electricity consumed, lower hardware costs, etc.
Answer: Confronted with the same questions as you, here is what I found:

Running CPU intensive tasks in VM makes no sense at all and quickly
becomes management nightmare ( it will influence all VMs one way or
another - no matter what your vendor marketing tells you)
For low CPU usage more cores outperform high frequency because of context switches and cache management.
Pretty much all of "professional" virtualization platforms use multi CPU setups with low-freq Xeons.

Considering all this, I am going with a second-hand 2*Xeon setup with 8 cores or more. It is even cheaper than some high-end i7
Answer:
if you seek benchmarks then you will find a lot at http://www.cpu-monkey.com
  and if you seek ratings then you could go for http://www.cpuboss.com
The answer to your question is that generally more frequency means higher processing speed and more cores/threads means better parallelism(more tasks are processed at the same time) and it should be a simple math problem but in the real world it depends on lots and lots of variables

1. Allocating Virtual cpu per core or per thread which can be detrimental to your VM's performance beside the not so obvious fact that overallocating to a VM could decrease its performance drastically.

for instance, your cpu has 8 cores but with hyperthreading they become 16 so you have 16 VCPUs ; if you allocate 1  VCPU to each VM which means 1 thread or half a core for each VM and you think thats enough for your VM then your VM could be faster than when it has got two threads(1 core) assigned
generally allocating on per core basis is less troublesome which means that xenon(with more cores) will probably outperform i7.

2. Overclocking = more speed ====> higher power-bill

Overclocking plus heat generated could render your system quite unstable and you will have to be very careful when choosing your power supply and your cooling system  beside the fact that it depends on your country's atmosphere
Example

people who report i7 is stable while overclocking live in a cold country and i used to see people asking if their cpu's temp. being 50c is very high and if it could lead to damage ,and that totally bedazzled me as my cpu's temp. while idle is 40 something(my country's weather temp. could easily get to 55c)which means xenon is better for me because it will be more stable and cooling will cost less even if it is slower than the i7.

3. Natural Limitations

programming languages and most programs are not yet optimized to take full advantage of all cores but can go better with threads and thats why you will see that i7 generally outperforms the xeon which is supposed to be a timetraveler.
even GPUs can be much better than both if you require pure parallelism.

4. More RAM is as much important as cpu performance if not more

upgrading my p.c. from 2GB RAM to 6GB made starting programs take less than half the time taken before , increased speed a lot and my processor doesn't undergo as much stress as before
more processor cache is better too.
i think you will need more than 16 GBs of Ram if you say "dozen" VMs which means that xeon is better .

5. Error correction, architecture and the way programs/scripts were written and compiled could make a processor slower than its less powerful counterpart.
6. Marketing people talking about and controlling what they can't understand thinking they "are" better than everyone which messes up everything.
7. Money Money Money Money Money Money (budget)
I think xeon e5-2687w v3 is the best in terms of computing power and life expectancy (vs. more powerful CPUs with more cores) as its all cores can be totally exploited , its cache is quite decent and at the same time it has a 3.1ghz freq which is very good but its very expensive in comparison to the i7 .


directive in angularjs does not show?

Question: I am playing around with a directive in an angular js application. This is a fragment of my directive:
(function() {
    var gMaps = function($timeout, $q, GeoCoder, mockdataService) {
      return {
        restrict: 'EA',
        template: '

',
        replace: true,
        link: function postLink(scope, iElement, iAttrs) {

..

In my index.html I have the directive:
 <gMaps center="map.center" zoom="map.zoom"></gMaps>

When I debug in the console it does not even hit the gmaps.js file? There are no visible errors in the console. What could be wrong?
this is a url for the plunkr: http://plnkr.co/edit/fEsaE9XpgmKFqO194X4G?p=preview
Answer: Change:
<gMaps center="map.center" zoom="map.zoom"></gMaps>

To:
<g-maps center="map.center" zoom="map.zoom"></g-maps>

EDITED PLNKR

directive in angularjs does not show?


update description from lead to existing contact

Question: When a Lead is converted, the "Description" of the lead is going to the "Description" of the newly created contact.
If I convert a Lead into an existing contact, then the "Description" of the lead goes nowhere.
 to add the Description of this lead to existing Description of the existing contact?
Answer: You could write a trigger on the Lead object.  You would need to check that the lead has been converted and it was converted to an existing Contact.  then you could append or replace the description on your Contact, whatever you want.
Something like this
<code>trigger LeadTrigger on Lead (after update) {

    map<Id,Contact> conMap = new map<Id,Contact>();

    for(Lead l : trigger.new){
        if(l.isConverted == true && trigger.oldMap.get(l.Id).isConverted == false){
            if(l.ConvertedContactId != null){
                conMap.add(ConvertedContactId,null);
            }
        }
    }
    conMap.addAll([Select Id, Name, Description From Contact Where Id In: conMap.keyset()]);

    for(Lead l : trigger.new){
        if(conMap.containsKey(l.ConvertedContactId)){
            //This is where you could do what you want with the lead description.
            //This is just replacing it, but you can do what you like.
            conMap.get(l.ConvertedContactId).Description = l.Description;
        }
    }
    update conMap.values();
}
</code>
Comment: or you could just use the '+' sign. it concatenates the whole string. but you'll have to check.
Comment: Correct, you could concatenation the description instead of just replacing it


Lyapunov stabilty, elementary question

Question: Let's say I have a system 1/(T1s+1) or any other n-th order polynomial and a PI controller (KP and TI). I already know that the system is stable but for, let's say, educational purposes (not homework), I want to test the stability using different stability criterions.
My question is:
Can I check if the system is stable or not by using Lyapunov stability criterion; similar to Nyquist or Routh-Hurwitz stability criterion? And how :) ? I was unable to find any examples on that or similar system.
I must admit that I am a beginner in the topic of stability, but as I see it Nyquist, Bode, Routh-Hurwitz they are more engineering orientated (i.e. in a few steps I can easily test the stability), while Lyapunov is not :(
Yet in almost every book Lyapunov's direct method is considered one of the best for determining the stability of dynamical systems!
Comment: As far as I understood the description on wiki, Nyquist, Bode, and Hurwitz criteria work only for linear time invariant systems, while Lyapounov criterion works for non-linear systems as well.
Answer: Short answer: Yes, you can.
Long answer: Here is how.
I remember we often used Lyapunov's direct method when studying nonlinear system analysis and control. It hinges on the following idea:
If the total energy of a system continuously decreases, then the system, whether linear or nonlinear, must eventually settle down to an equilibrium point.
Consider the linear time-invariant system from your example, i.e.
$$G(s) = \displaystyle\frac{1}{T_1s+1}, \quad T_1 \in \mathbb{R}_{>0}.$$
Then the time-domain description of the system is given by the following linear differential equation:
$$\dot{x}(t) + \frac{1}{T_1}x(t) = \frac{1}{T_1}u(t)$$
We would like to check the zero-input stability of the system with an arbitrary initial state, i.e. $u(t) = 0 \ \forall t \in \mathbb{R}_{\geq 0}$ and $x(0) = x_0$. Then we have
$$\dot{x}(t) = -\frac{1}{T_1}x(t)$$
with the equilibrium point at $x = 0$. Select a Lyapunov candidate function $V(x)$ as the square of the distance from the origin times a non-zero constant, e.g.
$$V(x) = \frac{1}{2}x^2.$$
Check that the above $V(x)$ satisfies the criterion for being a positive definite function:
$$V(x) \geq 0 \quad \forall x \in \mathbb{R}, \quad \text{and} \quad V(x) = 0 \iff x = 0.$$
Observe that $V(x)$ is a scalar function, which can be interpreted as the "energy function" of the system. Now, to check if the system is stable, we compute the "rate of change of energy", i.e. the derivative of $V(x)$:
$$\begin{aligned}\dot{V}(x) &= x\dot{x}\\
&= x\left(-\frac{1}{T_1}x\right)\\
&= -\frac{1}{T_1}x^2,\end{aligned}$$
which is negative definite. That is,
$$ \dot{V}(x) \leq 0 \quad \forall x \in \mathbb{R}, \quad \text{and} \quad \dot{V}(x) = 0 \iff x = 0.$$
So we may say that the system passively dissipates energy. Since

$V(x)$ is positive definite,
$\dot{V}(x)$ is negative definite, and
$V(x) \to \infty$ as $\|x\| \to \infty$,

then we conclude that the system is (globally) asymptotically stable at the origin in the Lyapunov sense.
Comment: What to do when I have second or third order polynomial? Then I have second (third) derivative on the "left" side! ___ I am actually trying to test the stability of an off-grid three phase inverter with cascade current and voltage controller. My initial idea was to determine the stability of d and q reference frame separately (as I did with Nyquist and Routh-Hurwitz). But now, I'm not sure! Is the Lyapunov stability of a three phase inverter usually determined in this way or by some other way?

Lyapunov stabilty, elementary question


How to choose a $\alpha$, $\beta$, $\gamma$ measurement detector?

Question: There are many different detectors for different radiation,such as NaI,HpGe,CsI for $\gamma$ detection,and ionization chamber,proportional counter,Geiger counter for $\alpha$, $\beta$ detection,but how to select a suitable detector for different radiation?I mean compare between them,what is the advantages and defects of them?
Comment: Unlisted detection technologies include, Cerenkov radiation, transition radiation, time projection chambers (both the traditional gas ones and the spiffy new liquid argon ones), plastic scintillators, liquid organic scintillators, cloud and bubble chambers, spark chambers, silicon photodiodes (in multiple classes), and on and on. You can be in this business for years and not really know them all.
Comment: This might help understand the detectors offered by the industry. http://www.reak.bme.hu/Wigner_Course/2004/WignerManuals/Bratislava/detectors.pdf .
Answer: In some sense the question is simple too big. I mean, it always comes down to a balance between your ultimate goal, your budget and any engineering constraints imposed by the goal.
Consider the differences between

a personal dose monitor (film badge, TLD, leaf electroscope...) which must be small and light enough to clip onto your person and can't run out of batteries either.
a survey meter used for checking the degree of radioactivation of material proposed for removal from a controled area (reactor facility, or whatever)
a combined PET/fMRI scanner (these are available now, but the expense in painful)
a visible cosmic ray demo for a museum
a in-the-hole device for a oil drilling company use to for understanding the geology under their feet

all the way up to things like

a ground station for a UHE cosmic ray experiment
a neutrino oscillation experiment
a collider experiment detector package

Like any other engineering situation we trade things off in order to get what we need (and maybe some of what we want) as easily as possible. In each case we consider things like

the range and energy of the radiation to be detected (you can't bury a alpha detection element behind in a sealed, rugged case, because the particles will range out before they get there)
the size of the detector elements (and the size of the readout equipment which may be separate) and their arrangement relative each other, the source and other bits which
the sensitivity and efficiency needs (to different kinds of radiation, to different energies that might be present)
Cost, cost, cost. Some of this kit can be very, very expensive, and you might choose a not-quite-the-best choice if you already have it and the necessary readout gear sitting around the lab from a old experiment. This is the equivalent of a "Don't laugh it's paid for" bumper sticker.
Comment: Excellent answer.  I am a "measurements specialist" in the Material Control and Accountability group on a fuel processing plant, we have three people in our group whose sole job is making these kinds of determinations for just our one plant and the few isotopes of concern.
Answer: Generally scintillation detector is used in the detection and measurement of gamma, beta and alpha activity. However, scintillator kept above the photomultiplier tube within the sealed detector differs in each case.

NaI (Tl) crystal is fitted above the  photomultiplier tube for gamma detection.
Plastic scintillator is fitted above the  photomultiplier tube for beta detection.
ZnS(Ag) is is fitted above the  photomultiplier tube for alpha detection.
Comment: This is also unduly simplified. We use plastic scintillator hodoscopes for gamma detection quite often when we only care about getting their direction (rather than calorimetry) simply because they are inexpensive ad can cover large areas. Nor are we restricted to scintillation: solid state detectors are very popular these days because of their small form factors and modest HV requirements. They are also exceeding good for modest energy alphas as many of them require no windows.


My grandfathers patented invention

Question: Can I collect royalties from a patent that a company in another country is producing that my grandfather invented?
My grandfather J.F. Mcdowell invented & patented the fishing tool used on oil rigs to retrieve tools that get dropped in a borehole. I've researched the timeline and discovered that many foreign businesses are producing the exact tool my grandfather invented. When researching the companies and the patent filed within that country, J.F Mcdowell is listed as the inventor. Is my family entitled to royalties??
Comment: In which country or countries did he patent his invention?  Do you have a reference to the patent?
Comment: Europe, Canada, Australia
Comment: Application # EP0460797A1 in Europe.   Apparently his patent is used worldwide.
Comment: EP0460797A1 European Application
Comment: For some reason I can't see any other comments
Answer: I see in the comments you list EP0460797A1. This application was granted as EP0460797B1 on 06/21/1995 and expired on 04/23/2011. So this patent is no longer in force and the invention described by it is freely available for anyone to use anywhere in the world. Even if it were in force, I doubt you would have any claim to royalties as the assignee is BetzDearborn Europe Inc. It is very common for inventions done while an employee to be owned (assigned) to the company and not the inventor.
Although you cite EP0460797A1, I rather doubt that this is invented by your grandfather. I found three US patents invented by John Frank McDowell including US1374510A, "Fishing Tool". These three patents were all in the US and all from the 1920s. Since patents of those eras expired 17 years from the grant date, they have all expired long ago. It is relatively common to have inventors with the same name so you have to be careful when searching.
In any case whichever John Frank McDowell we are citing, the patents are no longer in force and there is no potential for royalties.
Answer: You can look up the patent application status at Espacenet as well as other sites. It was filed in 1991 and therefore its 20 year term was up in 2011.  The legal status page is here.
If it was not expired any royalties would be due to the owner of the patent not necessarily an inventor or heir.
Comment: As I point out in my answer, I doubt the application cited in comments are from the same JF McDowell as the OPs grandfather.
Comment: Yes J F Mcdowell of Shreveport Louisiana is my great grandfather.  My dad's, mother's- father. He dis invent the 3 patents. Water controlled value. Safety switch for wells and the fishing tool for wells .  Please google the MCDOWELL BALL BEARING FISHING TOOL, Shreveport La. You will find plans for a plant to be built here in shreveport.  But he entrusted a banker named WADE Hampton.  Which lead to back stabbing, throat cutting, infringement..
Comment: https://www.patentguru.com/inventor/frank-mcdowell-john
Comment: I do greatly appreciate your help and your research you undertook on J F Mcdowell.  My grandmother would talk about her daddy inventing important devices. But he trusted someone that was a bad man. That was many moons ago . One night looking at old photo albums I ran across family events that made me think about my grandmother talking about her dad. So I did research and could not believe the devices he invented and that even today it's manufactured and used.
Comment: @debbieantley I can only  hope that my grandkids remember their granddad had some patents too.

My grandfathers patented invention


Using "$" in Groovy

Question: I see { } are used for closures, and then I believe when a $ is put in front of braces, it is simply doing a variable substitution within a string.  I can't find the documentation on how the $ works in the reference ... hard to search on it unfortunately, and the Groovy String documentation is lacking in introducing this.  Can you please point me to the documentation and/or explain the "$" operator in Groovy -- how all it can be used?   Does Grails extend it at all beyond Groovy?
Answer: In a GString (groovy string), any valid Groovy expression can be enclosed in the ${...} including method calls etc.
This is detailed in the following page.
Comment: One precaution that some of us may miss, do use double quotes to make it work i.e 'Hello ${varSam}' will not work but "Hello ${varSam}"
Comment: I never knew one could do so much in a GString.
Comment: Thanks for pointing that it's in the GString section.  The String section used ${} in one of its examples and didn't introduce it.
Answer: Grails does not extend the usage of $ beyond Groovy. Here are two practical usages of $
String Interpolation
Within a GString you can use $ without {} to evaluate a property path, e.g.
def date = new Date()
println "The time is $date.time"

If you want to evaluate an expression which is more complex than a property path, you must use ${}, e.g.
println "The time is ${new Date().getTime()}"

Dynamic Code Execution
Dynamically accessing a property
def prop = "time"
new Date()."$prop"

Dynamically invoking a method
def prop = "toString"
new Date()."$prop"()

As pointed out in the comments this is really just a special case of string interpolation, because the following is also valid
new Date().'toString'()

Comment: Isn't your 2nd usage just an example of the 1st?  As you can call methods by their string name like `new Date().'toString'()`? So it's just the first usage case to build a String which is then used to access methods/properties?
Comment: @tim - you're right, I guess what I'm really showing are two practical usages of string interpolation rather than two usages of $. I'll try and make this clearer
Comment: +1 from me :-)  Sorry I was being slightly pedantic, as it's a good example of where `$` is really useful
Comment: Cool - thanks for showing an example of dynamically accessing a property and dynamically invoking method
Comment: I'd like to mark yours as an answer as well, or raise the points, but it is not allowing me to.  Thanks for the grails clarification and examples.
Comment: if the string containing $variable, arrives from a select on the database, can it work?
Answer: $ is not an operator in Groovy.  In string substitution it identifies variables within the string - there's no magic there.  It's a common format used for inline variables in many template and programming languages.
All special Groovy operators are listed here: http://groovy-lang.org/operators.html
Answer: Work in side Jenkins File in pipeline
#!/usr/bin/env groovy
node{
          stage ('print'){
             def DestPath="D\$\\"
             println("DestPath:${DestPath}")
          }
}

Comment: Doesn't work. Jenkins complains about the "def".

Using "$" in Groovy


What is the difference between Symmetric authentication systems and Symmetric encryption systems?

Question: I know Symmetric encryption systems. Can someone explain the difference
Comment: Symmetric keys can be used for HMAC algorithms to prove data integrity of a stream cipher ie AES-CTR, what do you mean by symmetric authentication?
Comment: @SamG101 I think they mean HMAC/CMAC etc
Comment: Encryption aims at protecting confidentiality of some data, but does not necessarily provide authentication. Authentication aims at insuring that data comes from an authorized party and was not altered, but does not provide confidentiality. The concepts are orthogonal. The question is like asking what's the difference between a warm and a wear-resistant clothing.
Answer: In order to prove data integrity - I think this is what you mean rather that symmetric authentication - you can use a symmetric key with HMAC/KMAC.
These are varieties of message authentication codes, and these specific varieties use hash algorithms - SHA2/3/SHAKE. I'll use the example of AES-CTR with HMAC. To generate keys for this, use the HKDF-Expand, to derive the AES and HMAC keys individually.
The HMAC should have the input as the AES cipher text, (there is a question that talks all about Encrypt-Then-Mac, Encrypt-And-Mac, Mac-Then-Encrypt if you're interested: Should we MAC-then-encrypt or encrypt-then-MAC? ) and the HMAC key used to produce the tag. The tag is sent along with the ciphertext.
The HMAC proves the integrity of the AES data, because when the ciphertext is received, the recipient produces the HMAC from the recieved ciphertext. If the newly computed tag matches the tag that was sent along with the ciphertext, then the data integrity has been verified. If the tags dont match, it is evident that someone has tampered with the ciphertext during transmit.
Bit of extra info: there are varieties of the MAC algorithms:

HMAC (Hash-based message authentication code)
KMAC (Keccak-based message authentication code)
CMAC (Cipher-based message authentication code)
OMAC (One-time message authentication code)
GMAC (Galois-based message authentication code)


Change global keyboard shortcuts

Question: I use Alt+Space in Emacs, but in Xfce it pops up window manager menu at the upper left corner of a window. How do i disable Alt+Space for Xfce and change global keyboard shortcuts in general?
Answer: Here, in Xfce4 Settings Manager or launch xfce4-settings-manager from terminal,
In Window Manager configuration, find the keyboard part, look for Window operations menu, and then hit on Clear button, which will remove that shortcut key, effects immedately
Comment: It also allows to update other shortcuts, for example to move window to next/prev workspace. Very handy!
Answer: Go to Menu → Settings → Settings Editor, select "xfce4-keyboard-shortcuts", select xfwm4 → custom → <Alt>Space, then press "Reset property" button. Every other key combination can be set and unset there too.
Settings Editor is the general way to configure everything in Xfce4, though not user friendly.
Comment: Indeed it is not user friendly. However, is there any user friendly way to configure shortkeys? Where I can just press the keys to configure them?
Comment: There seem to be many keybindings that are not accessible via the Settings Manager, this is the only way I know to find them. I don't think either SM or SE are particularly user friendly, because you have to search around for the problematic keybinding. It would be nice if they had the ability to use the key combination and be brought to the setting to change.

Change global keyboard shortcuts


How insecure is it to publish my direct EC2 URL?

Question: I have a domain resembling the following from EC2:
<code>http://ec2-55-55-55-555.us-east-2.compute.amazonaws.com/
</code>
How problematic is it to publish this to the public with regards to security?
Answer: I'd be fairly certain that AWS is being scanned constantly by attackers, so running a webserver on port 80 shouldn't be considered a secret.  This is true in general for any publicly available service.
25 years ago people hooked up services on dialup modems with little or no security (default passwords).  They believed that the obscurity of the phone number was enough to protect them if they didn't publish the phone number, unaware of wardialers that had existed since the early 80s, the name stemming from the 1983 movie Wargames.
This sort of practice is called security through obscurity, and has been highly frowned upon for decades.  Essentially if you think you're safe because nobody will visit an IP address unless they're explicitly told about it, think again.
Answer: The only information in the URL is the IP address, the fact you are running on AWS and the region you are running in. None of that is a secret as this information can be trivially discovered anyway.
However if you are going to use the domain for a publicly accessible service it's better to create an Elastic IP, assign it to the server and point a canonical DNS name for the service  at the IP address.
Otherwise the address will keep changing for users if you move the service to another instance, or even stop and restart the server if you are not in a Virtual Private Cloud.


Bluetooth on a read-only system

Question: Oi, I am trying to say hello here... why are you deleting my "Hello all"...
Anyway, as the title suggests, I need some help with bluetooth on a read only system. After some playing around and following various guides, I came to the conclusion that I need to pair my phone and the rpi while the system is RW and not RO. After that, even if it is RO it will work without any issues. So the question is, where is that list of paired devices physically located, is it possible to move it to a different place (like an RW folder). Otherwise I will need to temporarily mount my root folder as RW, pair and then change it back to RO.
Thank you for reading me.
Comment: Hello @papatrexas. So a) Jessie is pretty old (just a warning) b) You may find a list of the files used by `bluetoothd` here: https://linux.die.net/man/8/bluetoothd (and by typing `man bluetoothd` in the terminal).
Comment: Oh, thanks mate.I will probably do the same thing I've done with samba to work on RO.
Answer: After user96931's suggestion, I did the following,
Made a folder named bluetooth in a partition that is ReadWrite (you need to have something like that)
sudo mkdir /home/bluetooth

Changed owner and perms
sudo chown nobody /home/bluetooth/

sudo chmod 777 /home/bluetooth/

Deleted the original /var/lib/bluetooth folder (didn't care about keeping any settings or paired devices)
Add a link from /home/bluetooth to /var/lib/bluetooth.
sudo ln -s /home/bluetooth/ /var/lib/bluetooth

Bluetooth on a read-only system


Exactly how does an oscillating electric field produce an oscillating magnetic field?

Question: Let's say we have a capacitor which is connected to a sinusoidal voltage source, that means that the electric  field within the capacitor is a sinusoidal function(assuming that the capacitor is a parallel plate capacitor ),  but how does this model generate any magnetic field? If it does,  then doesn't that mean that light is generated within the capacitor?
Comment: https://en.wikipedia.org/wiki/Displacement_current
Comment: @CountIblis So,  doesn't that totally mean that light is produced inside a capacitor?
Comment: Yes, but that doesn't depend on that capacitor per se, all you need is the oscillating current in  the wire.
Comment: @CountIblis But that's a different thing, since the light is produced from an intentional magnetic field
Answer: According to the Maxwell equation $$ curl{\vec H} = \vec j + \epsilon \frac{∂\vec E}{∂t}$$ An oscillating electric $\vec E∝ exp{(i\omega t)}$ field creates a displacement current density $j_D=\epsilon \frac{∂\vec E}{∂t}=i\omega\vec E$ that is equivalent to a current in creating a magnetic field that encircles the sum of convection and displacement current. Therefore, in a capacitor with an oscillating electric field producing a displacement current $j_D$, a magnetic field encircles the displacement current in the capacitor just like the corresponding conduction current in the wire leads to the capacitors. In a normal capacitor it is practically impossible to have field oscillations in the light frequency range. Therefore you will have no light generation. But you could have radio frequency wave generation. This is, e.g., the case in an oscillating dipole antenna which is similar to an open capacitance-inductance electric oscillator.
Comment: Radio waves are still light
Answer: There is a correction to the Ampère Law that says that a variation of the flux of the electric field in a surface produce a circulation of a magnetic field around the surface. This is translated to:
$$
\oint_{\partial A}B\,d\ell= \varepsilon_0\mu_0 \,\frac{d}{dt}\int\int_A \hat{n}_A \cdot \vec {E} \,dA
$$
As the electric field oscilates, if you look at a surface parallel to the plates you would see a circulation of the magnetic field. This circulation oscilates in the same frequency. And there would be production of light, dissipating the energy delivered into the capacitor. To make this system stationary you need to provide this energy all the time. Is impossible for this light being a visble light though. The capacitor need to be very thin and oscilating very fast. To produce visible light you always new to oscilate small things, like excitations of electron-hole pair in semiconductors or vibrations of electrons in atoms and molecules.


What should I do about ChatGPT content in questions (not answers)?

Question: I came across a question today that pasted a ChatGPT answer into the question. How can I handle such a case?
Comment: If the content isn't helpful to the post, and it's noise, edit it out. The user in question, however, is misusing the code fence/block markdown; answers from ChatGPT isn't code and shouldn't be identified as code. Text from ChatGPT should be in a quoteblock.
Comment: *"how about if the ChatGPT answer does add some relevant info?"* If it's not properly attributed then, at the bare minimum, it's not following the referencing guidelines and at worst it's malicious plagiarism. Though [ChatGPT answers are currently banned](https://meta.stackoverflow.com/questions/421831/temporary-policy-chatgpt-is-banned?cb=1), so if you see a ChatGPT answer at the moment, then you should probably be flagging it as such.
Comment: @Larnu it seems all ChatGPT content is banned, whether it's in questions or answers.
Comment: An example of ChatGPT-generated code in [a question](https://stackoverflow.com/questions/76521808/warning-maximum-update-depth-exceeded-useeffect-problem/76522091#comment134975665_76522091): *"I've done prompt engineering to compose this code"*
Comment: @Larnu revised the question to make it more general. In this case it was noise, how about if the ChatGPT answer does add some relevant info?
Comment: You were asking about answers in your [comment](https://meta.stackoverflow.com/questions/421960/what-to-do-about-chatgpt-content-in-questions-not-answers?noredirect=1#comment937975_421960), @bad_coder , hence why I mentioned answers.
Comment: @Larnu yes, I said the user posted an answer in the question - I'm unaware of ChatGPT also generating questions :P
Answer: We do not need to go to every existing rule and every existing answer and inject "ChatGPT" into it. The only thing that is special about it is that it is being abused on a large scale because it is easy to do so.
The answer to this question is exactly the same as the answer to the question "I came across a question today that pasted an answer into the question. How to handle such a case?". Well:
What is the appropriate action when the answer to a question is added to the question itself?
I'm sure there are numerous meta posts which answer permutations of it, like "... and the answer is bad".
Comment: The answer to this question isn't the same as in the other cases, I just looked carefully at the ChatGPT announcement and the last paragraph states all ChatGPT content is banned whether it's in answers or questions. So this raises the issue of whether editing out the content is enough or the question should be closed/deleted due to the specific ban - a matter of policy that hasn't been addressed yet.
Comment: Also, quoting the announcement: *"If a user is believed to have used ChatGPT after this temporary policy is posted, sanctions will be imposed to prevent users from continuing to post such content"* I'm unsure if it's moderator flag worthy.
Answer: TL;DR:

Edit out the answer from the question.
Flag the question for moderator attention with an explanation along the lines of: "This question had an AI generated answer inside it. I edited it out but according to policy flagging as this is banned".
Leave a comment on the question explaining that answers don't go in the question and that content from CGPT is strictly not allowed.

The way I see it, there are three aspects to address here.
First of all, to remove the specific-case issue: in the example you gave, the use of CGPT is purely noise and shouldn't even warrant a special treatment, IMO. It is semantically the same as if it had something like: "Even Wikipedia couldn't help me: <quote from Wikipedia>". That's just noise and could (should) be edited out.
Now in case you meant this as a more general question, we have two aspects:

Answers shouldn't be posted in questions. This is a Q&A site and posts should stick to the format. Follow the same guideline as What is the appropriate action when the answer to a question is added to the question itself? (*caveat coming up)

Content produced by CGPT is currently banned. While a bit hidden away in all the commotion, the guideline seems to be to flag for moderator attention.

(*promised caveat:) Combining (2) with (1) it's probably best not to actually post the answer as a CW (or any other form), and modify the comment you would leave with the guideline about CGPT.


Can you customise blogger invitations so they have to identify themselves as being in a particular group

Question: When I send out invitations to a private blog can they be asked to fill something in so we can distinguish comments from 'small', 'diaspora', 'African counterparts' and 'other key stakeholders'. Is there any way we can do this?
Answer: There is no functionality for this within Blogger's(*) invitation-to-participate process:  you cannot customize this email at all.
But I guess that as an adiministrator you could set up a Google Form, and when someone accepts the invitation, send them a follow-up email welcoming them and asking them to complete the form, and then manually using the results to update a profile you have for them.
Yes, this is more work.   But since you can only ever invite up to 100 people to each private blog, it may be manageable.
(*)  since you used the Blogger tag, I've assumed that you mean Google's Blogger product.   I don't know what options other blogging products may have.


any command line com port query tools?

Question: I want to make a chat program that uses SMS as its base engine. To do this I need to communicate with my GSM phone via Bluetooth attached to COM7 on my computer. I can do this fine using HyperTerminal, Tera Term etc.
But to have an unobtrusive, friendly interface I need a command line tool to send AT commands, (and receive responses) to/from my mobile phone through my COM port. I have been searching for days to no avail. Is there anything that I have missed?
Answer: It's probably not exactly what you want but I wrote a python framework for communicating via AT-commands. It supports data cables, bluetooth on Linux and Windows (written in Python 2).
A sample program built with that framework is RecNPlay. With RecNPlay you are able to record (, save) and playback keystrokes on your mobile phone.
You could take RecNPlay as an example and program your own tool to communicate. The library RecNPlay is built on is called PyGSMLib and provides python-wrappers to a lot of AT-commands and supports 'AT unsolicited results'.
Sample python program which listens to Nokia specific GPRS events (like connect, disconnect from mobile, disconnect by network):
<code>device = sys.argv[1]

sconn = None
comm = None
try:
    sconn = Serial(device, 9600, timeout=3)
    print "Initializing V250 connection...",
    comm = V250Communicator(sconn)
    print "ok"
    gsm = NokiaController(comm, True)
    gsm.nokiaEnableGprsEventReporting()
    def listen(msg):
        print "Unknown: %s" % str(msg)

    comm.setUnsolicitedResultListener(listen)
    import os
    os.sys.stdin.readline()
finally:
    if sconn:
        sconn.close()
</code>

any command line com port query tools?


In The Matrix Resurrections, can Neo see the real image of Trinity or only her Digital Self Image (DSI)?

Question: Can Neo see Trinity like she actually looks like or just her DSI? And what about how Trinity sees Neo?
Answer: Neo seems startled when he sees a reflection in the table that shows her as a blond woman. It seems likely that he sees her as she should be, rather than the altered DSI that the new Matrix is attempting to present to everyone else.

It's not clear how Trinity sees Neo, but we can probably assume that much the same holds true for her as for him since she has a very similar set of superpowers. Note also that she isn't startled by his appearance when she sees him later on (jacked in) and not subject to the same controls over his DSI as before.


What is meant by topology of DNA?

Question: I couldn't find anything on internet that would give a clear-cut idea about what it could be.
Comment: Lehninger has got a good section on dna topology along with the function of topoisomerases.
Answer: Topology is the study of flexible geometries. That is, what properties do objects have when you're allowed to stretch and bend them (but not allow them to break or pass through themselves). This is the origin of the saying that to a topologist there's no difference between a doughnut and a coffee cup. Topologically, they're the same object. If the doughnut and coffee cup were made of really elastic putty, you could  remold one into the other without cutting it, or allowing it to pass through itself.
So what does this have to do with DNA? Well, while DNA is stiff on short scales (dozens of base pairs), when you get long stretches of DNA it's very flexible. You can bend and wrap the DNA up. But there's a limit on what you can do without breaking it or letting it pass through itself. (For circular DNA) You can't get knots, and the intrinsic double-helical "twist" of the DNA can't be changed.
There are various enzymes in the cells (helicases, topoisomerases) which are responsible for controlling this coiling and twisting. The way they work is to (temporarily) make a break in the DNA, pass the DNA strands through the cut, and then reclose the strands. That is, they change the topology of the DNA. This is how you get "overwinding", "underwinding" and "supercoiling"
So "the topology of DNA" is talking about the properties and geometry of DNA that it has if you treat it as an unbroken floppy noodle: how it's wrapped up and how it's twisted.

What is meant by topology of DNA?


Are children eligible for British citizenship when one of the parents acquire settled status?

Question: I am getting settled status (ILR) this August. My daughter is Indian, and was born three years ago in the UK. Is she eligible for British citizenship once I acquire ILR? Or is she eligible only at the same time as myself, when I apply for citizenship a year later?
Comment: Strictly speaking, "settled status" means that you're participating in the EU settlement scheme.  The term that encompasses all the various statuses that lead to children being UK citizens from birth, including citizenship, ILR, settled status, and some others, is "settled in the UK."  It's confusing.  Whether you're truly getting settled status or another form of ILR doesn't affect the answer to this question (aside from the question of which bullet point to call attention to), but it might have other implications for you.
Answer: Your daughter can register as a British citizen when you acquire ILR: From https://www.gov.uk/apply-citizenship-born-uk/under-18 (emphasis added):

If you're under 18
You can register to become a British citizen if one of your parents considered the UK as their home and did any of the following after you were born:

became a British citizen
got indefinite leave to remain in the UK
got 'settled status' (also known as 'indefinite leave to remain under the EU Settlement Scheme')
got indefinite leave to enter the UK
got permanent residence status

You must have been born in the UK and be under 18 when you apply.

If for some reason you don't acquire ILR as you expect to do, your daughter can register as a British citizen after she turns 10 (subject to a condition limiting her absences from the UK to less than 90 days each year).  Details are shown at https://www.gov.uk/apply-citizenship-born-uk/uk-until-10
The fee is heavy, currently £1013, but it seems to be the same for both routes.


Superconductive magnet as a source of energy?

Question: Could we charge a superconductive magnet and use it as a source of energy?
Answer: Yes. The energy expended in producing the magnetic field can be recovered during the field's collapse, which occurs after the current producing the field is shut off.
For example, the amount of energy stored in the superconducting magnets that steer the particle beams in CERN's Large Hadron Collider is equal the the kinetic energy of a fully-loaded jumbo jet going 500 MPH. Shutting the magnets down requires dissipating all that energy, and if anything goes wrong during that process, parts of the collider will get blown to pieces in an instant.
Note that the energy stored in the magnetic field of a superconducting magnet did not get there for free. When running, those magnets and the machinery needed to support them consume as much electrical power as a small city, for which CERN pays the bill.
Comment: @Barfieldmv Heating the supercooled magnets also blows them up (if not done in a controlled and slow way). That's what happened back in 2008 when it was first turned on and it took two years to fix.
Comment: the net energy from a lightning strike isn't big enough to justify the cost of collecting it. because of the huge amount of bother in maintaining the liquid helium for the superconducting magnets, I see them as appropriate only in research and experimental settings. this would change when high-temperature superconductivity becomes real.
Comment: this has in fact been considered as a way to temporarily store electrical power, but there are other ways (like ultracentrifuge flywheels) that do not require refrigeration and are portable.
Comment: regarding safety, any energy storage methodology that exhibits similar energy density to gasoline is going to have hazards associated with it. For example, getting into a crash with a flywheel storage system will break the flywheel loose and it will either explode into a million pieces or take off a tremendous speed and strike something expensive. in the case of high-capacity batteries, simply shooting an arrow through  it will short-circuit it internally, after which it will explode with great force.
Comment: Or even worse then blowing things up would be heating up the supercooled magnets.
Comment: What are best applications of those magnets? What do you think of using superconducting magnet for storing energy from lightning strike? (https://patents.google.com/patent/US5367245)
Comment: Let's assume the HTS technology is real. Would it be possible then to build a HTS electro-magnet for storing energy in EVs? How would such magnet stand compared to standard lithium batteries? How's safe to carry a HTS magnet in a vehicle?
Answer: Yes, in the same sense that you can store energy in a battery and then use the battery as a source of energy. See for example this Wikipedia article.


Libreoffice Calc - Fill with Sum is not working

Question: I want to add 2 columns of data and output the sum into a third column, with a =sum(a1+b1).  With many rows of data, I try dragging down the highlighted cell to Fill the rest of the output column with the sum function.  However, the top number is propagated to the rest of the rows, even though the function in the cell appears to be correct (for example =sum(a3+b3)).  Is this a bug?  My data is not text, no leading spaces, etc.  Thanks.
Answer: No, it is not a bug.
If you get the result you expected from keyeing F9 you might want to go to Tools, Calculate and check AutoCalculate.
As an aside =a1+b1 should be sufficient instead of =sum(a1+b1).
Comment: Yes, thank you!  The toggle was actually located in Tools -> Cell Contents.  This should be on by default! :)