Equation of motion, Newtonian mechanics

Equation of motion (Newtonian mechanics) is:

F=ma

where
F: force
m: mass
a: acceleration

Every location in the universe is characterized by a gravitational field constant represented by the symbol g (sometimes referred to as the acceleration of gravity). Thus weight and mass can be related as follows:

Weight = mg

where
Weight: weight
m: mass
g: acceleration of gravity

Referance:
Mechanics: Newton's Laws of Motion (http://www.physicsclassroom.com/calcpad/newtlaws )

The Greatest Blessing

2.4 The Greatest Blessing
Mahāmaṅgala Sutta

Thus have I heard. On one occasion the Exalted One was dwelling at Anathapindika's monastery, in Jeta's Grove, near Savatthi. Now when the night was far spent, a certain deity whose surpassing splendor illuminated the entire Jeta Grove, came to the presence of the Exalted One and, drawing near, respectfully saluted him and stood at one side. Standing thus, he addressed the Exalted One in verse:

261.

Deva: 

Many deities and men, yearning after good, have pondered on blessings. Pray, tell me the greatest blessing!

262.

Buddha:

Not to associate with the foolish, but to associate with the wise; and to honor those who are worthy of honor — this is the greatest blessing.

263.

To reside in a suitable locality, to have done meritorious actions in the past and to set oneself in the right course — this is the greatest blessing.

264.

To have much learning, to be skillful in handicraft, well-trained in discipline, and to be of good speech — this is the greatest blessing.

265.

To support mother and father, to cherish wife and children, and to be engaged in peaceful occupation — this is the greatest blessing.

266.

To be generous in giving, to be righteous in conduct, to help one's relatives, and to be blameless in action — this is the greatest blessing.

267.

To loathe more evil and abstain from it, to refrain from intoxicants, and to be steadfast in virtue — this is the greatest blessing.

268.

To be respectful, humble, contented and grateful; and to listen to the Dhamma on due occasions  — this is the greatest blessing.

269.

To be patient and obedient, to associate with monks and to have religious discussions on due occasions — this is the greatest blessing.

270.

Self-restraint, a holy and chaste life, the perception of the Noble Truths and the realisation of Nibbana — this is the greatest blessing.

271.

A mind unruffled by the vagaries of fortune, from sorrow freed, from defilements cleansed, from fear liberated — this is the greatest blessing.

272.
Those who thus abide, ever remain invincible, in happiness established. These are the greatest blessings.

The Serpent Sutta Uraga Sutta

1.1 The Serpent Sutta Uraga Sutta

1.
Who removes arisen anger
as herbs a serpent’s venom spread;
a bhikkhu such leaves here and there
as a serpent sloughs its worn-out skin.

2.
Who lust pulls up remainderless
as in water, plants and blooms of lotuses;
a bhikkhu such leaves here and there
as a serpent sloughs its worn-out skin.

3.
Who craving dams remainderless
as drying of a river’s fierce and rapid flow;
a bhikkhu such leaves here and there
as a serpent sloughs its worn-out skin.

4.
Who destroys conceit entire
as a great flood a bridge of reeds so frail;
a bhikkhu such leaves here and there
as a serpent sloughs its worn-out skin.

5.
Who in rebirths no essence finds
as a seeker of flowers on Udumbara trees;
a bhikkhu such leaves here and there
as a serpent sloughs its worn-out skin.

6.
Who keeps no grudges inwardly
but this “being-not being” has gone beyond;
a bhikkhu such leaves here and there
as a serpent sloughs its worn-out skin.

7.
In who do thoughts no longer smoulder,
internally curtailed, remainderless;
a bhikkhu such leaves here and there
as a serpent sloughs its worn-out skin.

8.
Who neither goes too far nor lags behind,
all mind-proliferation gone beyond;
a bhikkhu such leaves here and there
as a serpent sloughs its worn-out skin.

9.
Who neither goes too far nor lags behind,
who of the world has Known, “All is not thus”;
a bhikkhu such leaves here and there
as a serpent sloughs its worn-out skin.

10.
Who neither goes too far nor lags behind,
who free of greed has Known, “All is not thus”;
a bhikkhu such leaves here and there
as a serpent sloughs its worn-out skin.

11.
Who neither goes too far nor lags behind,
who free of lust has Known, “All is not thus”;

a bhikkhu such leaves here and there

as a serpent sloughs its worn-out skin. 

12.

Who neither goes too far nor lags behind,

who free of hate has Known, “All is not thus”;

a bhikkhu such leaves here and there

as a serpent sloughs its worn-out skin.

13.

Who neither goes too far nor lags behind,

who delusion-free has Known, “All is not thus”;

a bhikkhu such leaves here and there

as a serpent sloughs its worn-out skin.

14.

In whom are no latent tendencies at all—

whose roots of evil completely are expunged;

a bhikkhu such leaves here and there

as a serpent sloughs its worn-out skin.

15.

In whom is no anxiety at all

to cause return to this existence here;

a bhikkhu such leaves here and there

as a serpent sloughs its worn-out skin. 

16.

In whom no attachment formed at all

to cause return to all existences;

a bhikkhu such leaves here and there

as a serpent sloughs its worn-out skin.

17.

Who’s left behind five hindrances,

serene then, crossed doubt, lacking inner barbs;

a bhikkhu such leaves here and there

as a serpent sloughs its worn-out skin.

How to learn

Learn abstract or logical concepts

When you try to learn something complicated, abstract or logical concepts, explain the
something with your word.

Quote from Richard Feynman:

The only way to have real success in science, the field I’m familiar with, is to describe the evidence very carefully without regard to the way you feel it should be. If you have a theory, you must try to explain what’s good and what’s bad about it equally. In science, you learn a kind of standard integrity and honesty.  

I don't know who said this, but this is good quote as well:

You do not really understand something unless you can explain it to your grandmother.

If you can't explain it, it means you don't fully understand it. Hence if you can explain it, (ideally) without looking at any text or memo, it means you fully understand it.

Explain

If you can explain the something with your word, that means you understand what it is. The intention of this is to memorize the concept as "Episodic memory" rather than "Semantic memory" because episodic memories are usually easier to recall.  

1. Suppose we want to learn how to use "cd command" (which is a command used for command line).
2. Read the explanation and try to understand what it says.

For example,

CD (Change Directory) is a command used to switch directories in MS-DOS and the Windows command line...
 -cited from Computer Hope http://www.computerhope.com/cdhlp.htm

3. Without looking at the explanation, try to explain what you have read just now "with your words".

If I explain "cd" with my words:

cd is a command used to move to other directories from a current directory in the windows command line and other similar systems... 

(Just verbal explanation is also ok, but it's better if you write it down because you can refer to it later and it is good to memorize the explanation. Markdown (How to use Markdown) is good to make a clean-looking explanation easily.)

4. If you could explain the thing with your words, it means you have understood the concept.
5. Go to another page of the textbook and learn another thing.

"cd" is already learned because you could explain the thing without looking at its explanation. So go to another page of the textbook and maybe learn "ls" command...

We used "cd command" for example here, but this "thing to learn" can be anything; mathmatical concept, programming language and so on.

In short, to learn something abstract, explain it. Explain correctly but with your word.

(But explain with honesty. Honesty is important when you write reports or research papers and so on in your future.)

Mindmap

When you get used to learning by explaining, you can also try Mindmap. You can make notes of variety of things with shorter time if you use mindmap. Also, it contains colors, images, relationships expressed by connectors, so it is good to organize and memorize things. 

I use mindmap to take notes during meetings, but it is very good to organize what is discussed in the meetings. I think this is also good to take notes during lectures.

Some mindmap tools can be used for free. Maybe like xmind8 or Freeplane?

Memorizing foreign words

Let's say, we will memorize Japanese words and their meanings. For example, this word 行く(iku, yuku), which has a lot of meanings.

行く means to go, move to, (with で) go with, to continue etc.

But actually you don't need to memorize all of the meanings. Because you can guess the meaning from the first meaning "to go". Almost all of the other meanings come from the metaphor of "to go".

So what you need to do is memorize the first meaning "to go". If you know the first meaning, actual meaning of 行くcan be guessed from the context. In fact, this is what native speakers do. They don't memorize all of the meanings like dictionary.

So, to memorize foreign words, my recommendation is always memorize only one or two meanings for each word. Not more than two. It makes memorization easier and also makes imagination of the meanings easier.

Memorizing foreign words 2

It is very important to repeat "forgetting" and "recalling" to memorize. Let's say, we want to memorize these 4 french words: acheter, écouter, tante, bras. 

At first, we check the first two words and carefully read them.

acheter: buy

écouter: listen

Then carefully read next two words:

tante: aunt

bras: arm

Then you should have forgotten the first two french words and its meanings. Try to recall them.

If you have successfully recalled that they were acheter (buy) and écouter (listen), then you should have forgotten the next two french words. Try to recall them. 

If you have successfully recalled they were tante (aunt) and bras (arm), then go to the next 4 words. If you have failed, go back to the first words.

Memorizing mathematical formulae

This page might help. Also my recommendation is to install an app for mathematical formulae and try to memorize in bus, train or in bed. If you use your phone to study, you don't need to use your desk, which makes you less tired.

Moreover, if you study in bus or train, you can avoid wasting time that is spent for commuting. Study and try to memorize everyday. It is how I studied.

For solution for Math problems, I think the important thing is to understand the strategy. Look at the math problem, and if you can explain how to solve the problem, ot means that you know enough for the math problem.

Motivate yourself

When you don't feel like studying, it is very hard to start studying on a desk. In my opinion, it is almost impossible to study and get a meaningful result when you aren't motivated. You might think, even if you aren't motivated, you can force yourself to be at desk and start studying. It might be possible for a very short period to force yourself to study even if you aren't motivated, but from my experience, it won't last long. 10 or 15 minutes later, you just leave the desk for something else.

What I want to emphasize here is motivating yourself is very important. For example, when I want to study something for programming, I watch something that motivates myself at first. Check information on exciting new programming tools (maybe something like K8S), watch youtube videos which are provided by exciting programmer, or read some interesting anecdotes of programming on internet. Anything is OK to motivate you.

But without being motivated, you can't keep studying for a long time. Don't forget to motivate yourself. Motivation doesn't appear out of nowhere.

  

Decline

I have heard that at one time the Blessed One was staying near Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s monastery. Then a certain deva, in the far extreme of the night, her extreme radiance lighting up the entirety of Jeta’s Grove, went to the Blessed One.

On arrival, having bowed down to him, she stood to one side.
As she was standing there, she addressed him with a verse:
About the man in decline we ask Gotama, having come to question the Blessed One:
What is the way leading to decline?

The Buddha:
Easily known is the one of good prospects; easily known, the one in decline.
The one of good prospects loves the Dhamma,
the one in decline detests it.

The deva:
We know, indeed, that that is so.
That’s the first one in decline.
May the Blessed One tell the second:
What is the way leading to decline?

The Buddha:
The wicked are dear to him,
the good he doesn’t hold dear.
He approves of the ideas of the wicked:
That is the way leading to decline.

The deva:
We know, indeed, that that is so.
That’s the second one in decline.
May the Blessed One tell the third:
What is the way leading to decline?

The Buddha:
Prone to sleep, prone to company,
the man with no initiative,
lazy & known for his anger:
That is the way leading to decline.

The deva:
We know, indeed, that that is so.
That’s the third one in decline.
May the Blessed One tell the fourth:
What is the way leading to decline?

The Buddha:
Though capable, one doesn’t support
one’s mother or father —old, their youth over & done:
That is the way leading to decline.

The deva:
We know, indeed, that that is so.
That’s the fourth one in decline.
May the Blessed One tell the fifth:
What is the way leading to decline?

The Buddha:
Whoever deceives with a lie a brahman, contemplative, or other mendicant:
That is the way leading to decline.

The deva:
We know, indeed, that that is so.
That’s the fifth one in decline.
May the Blessed One tell the sixth:
What is the way leading to decline?

The Buddha:
The man of great wealth, with gold & food, enjoys his luxuries alone:
That is the way leading to decline.

The deva:
We know, indeed, that that is so.
That’s the sixth one in decline.
May the Blessed One tell the seventh:
What is the way leading to decline?

The Buddha:
The man proud of his birth,
proud of his wealth,
proud of his clan,
despises his own relatives:
That is the way leading to decline.

The deva:
We know, indeed, that that is so.
That’s the seventh one in decline.
May the Blessed One tell the eighth:
What is the way leading to decline?

The Buddha:
The man debauched with women,
debauched in drink,
debauched in gambling,
squanders his earnings:
That is the way leading to decline.

The deva:
We know, indeed, that that is so.
That’s the eighth one in decline.
May the Blessed One tell the ninth:
What is the way leading to decline?

The Buddha:
One uncontent with his own wives,
misbehaves with prostitutes & the wives of others:
That is the way leading to decline.

The deva:
We know, indeed, that that is so.
That’s the ninth one in decline.
May the Blessed One tell the tenth:
What is the way leading to decline?

The Buddha:
His youth past, a man takes a young woman
with timbara-fruit breasts, and, jealous of her, doesn’t sleep:
That is the way leading to decline.

The deva:
We know, indeed, that that is so.
That’s the tenth one in decline.
May the Blessed One tell the eleventh:
What is the way leading to decline?

The Buddha:
To place in authority a woman given to drink & squandering or a man of that sort:
That is the way leading to decline.

The deva:
We know, indeed, that that is so.
That’s the eleventh one in decline.
May the Blessed One tell the twelfth:
What is the way leading to decline?

The Buddha:
One of meager means but great craving,
born into a noble family, who aspires to kingship:
That is the way leading to decline.
Contemplating these ones in decline in the world,
the wise one, consummate in noble view,
heads to a world auspicious.



Citation from www.dhammatalks.org
https://www.dhammatalks.org/Archive/Writings/SuttaNipata160803.pdf

sutta nipata

The Serpent

Dhaniya the Cattleman

The Greatest Blessing

Decline

Dhaniya the Cattleman

Dhaniya the cattleman:
“The rice is cooked,
my milking done.
I live with my people
along the banks of the Mahi;
my hut is roofed, my fire lit.
So if you want, rain-god,
go ahead & rain.”

The Buddha:
“Free from anger,
my rigidity gone,
I live for one night along the banks of the Mahi;
my hut’s roof is open, my fire out.
So if you want, rain-god,
go ahead & rain.”

Dhaniya:
“No mosquitoes or gadflies are to be found.
The cows range in the marshy meadow where the grasses flourish.
They could stand the rain if it came. So if you want, rain-god, go ahead & rain.”

The Buddha:
“A raft, well-made, has been lashed together.
Having crossed over, gone to the far shore,
I’ve subdued the flood.
No need for a raft is to be found.
So if you want, rain-god, go ahead & rain.”

Dhaniya:
“My wife is composed, not wanton, is charming, has lived with me long.
I hear no evil about her at all. So if you want, rain-god, go ahead & rain.”

The Buddha:
“My mind is composed, released, has long been nurtured, well tamed.
No evil is to be found in me. So if you want, rain-god, go ahead & rain.”

Dhaniya:
“I support myself on my earnings. My sons live in harmony, free from disease.
I hear no evil about them at all. So if you want, rain-god, go ahead & rain.”

The Buddha:
“I’m in no one’s employ, I wander the whole world on the reward [of my Awakening].
No need for earnings is to be found. So if you want, rain-god, go ahead & rain.”

Dhaniya:
“There are cows, young bulls, cows in calf, & breeding cows, & a great bull,
the leader of the herd. So if you want, rain-god, go ahead & rain.”

The Buddha:
“There are no cows, no young bulls, no cows in calf or breeding cows, no great bull, the leader of the herd. So if you want, rain-god, go ahead & rain.”

Dhaniya:
“The stakes are dug-in, immovable.
The new muñja-grass halters, well-woven, not even young bulls could break.
So if you want, rain-god, go ahead & rain.”

The Buddha:
“Having broken my bonds like a great bull,
like a great elephant tearing a rotting vine,
I never again will lie in the womb. So if you want, rain-god, go ahead & rain.”

The great cloud rained down straightaway, filling the lowlands & high.
Hearing the rain-god pour down, Dhaniya said:
“How great our gain that we’ve gazed
on the Blessed One!
We go to him,the One with Eyes, for refuge.
May you be our teacher, Great Sage.
My wife & I are composed.
Let’s follow the holy life
under the One Well-Gone.
Gone to the far shore
of aging & death,
let’s put an end
to suffering & stress.”

Māra:
“Those with children delight because of their children.
Those with cattle delight because of their cows.
A person’s delight comes from acquisitions, for a person with no acquisitions doesn’t delight.”

The Buddha:
“Those with children grieve precisely because of their children.
Those with cattle grieve precisely because of their cows.
A person’s grief comes from acquisitions,
for a person with no acquisitions doesn’t grieve.”


Citation from www.dhammatalks.org
https://www.dhammatalks.org/Archive/Writings/SuttaNipata160803.pdf