Golden age of Islam

WEBVTT
Kind: captions
Language: en

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- [Instructor] In other
videos we talk about the rapid

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spread of Islam, and one
of the interesting things

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about these early Islamic empires

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is they preserved much
of what they inherited

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from the Byzantine and
the Persian empires.

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The infrastructure including the roads,

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the bureaucracy.

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A lot of the culture.

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And they also began to
collect the knowledge

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from within the empire
and from the peoples

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that they encountered on
the borders of the empire

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including the Indians, and the Chinese.

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And they did this throughout
the Umayyad dynasty.

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But it really came to its full fruition

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during the Abbasid Caliphate.

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Now the Abbasid Caliphate,
one of the first things

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they did under the Calph al-Mansur

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is build Baghdad and move
the capital of the empire

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to Baghdad.

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Now one of al-Mansur's successors

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al-Rashid, is famous for making Baghdad

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a center of learning.

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According to the historian
John William Draper

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this is a sense of what life was like

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under al-Rashid's rule.

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During the period of the
Calphs the learned men

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of the Christians and
the Jews were not only

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held in great esteem, but were appointed

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to posts of great responsibilities

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and were promoted to
the higher ranking jobs

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in the government.

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He, Calph Haroon Rasheed, never considered

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to which country alerted person belonged

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nor his faith in belief
but only his excellence

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in the field of learning.

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And to get a sense of how much learning

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and how advanced the knowledge began to be

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especially under the rulership

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of al-Rashid, during this time

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he was a contemporary of Charlemagne

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who was the Frankish king.

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He was also the first holy Roman emperor.

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And so it's this region right over here.

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And they were trading gifts

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and this is a historical account

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Haroon al-Rashid sends

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Charlemagne this water clock.

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And it's so foreign to the Francs

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to Charlemagne, that he thinks that it's

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it must be some type of magic.

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That it can't be explained
by just normal means.

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And then things really
get invested in terms

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of collecting knowledge

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as we get into the rule of al-Rashid's son

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al-Ma'mun where he creates in Baghdad

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what is called The House of Wisdom.

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Which is this center of learning,

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of mathematics, astronomy, physics,

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medicine, geography, and map making,

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poetry, philosophy.

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And, over the next several hundred years

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these Abbasid Caliphs are going to

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sponsor scholars from India,

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learn it in Sanskrit and
the ancient Sanskrit text

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in Greek, Chinese, Persian
to translate as much

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of the knowledge and to collect it

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in libraries in cities, like Baghdad.

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To translate it into
Arabic, and to collect all

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of that knowledge in one place.

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And just to get a sense
of the type of advances

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that occurred during
this golden age of Islam

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which correlates strongly,
or is essentially during

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the Abbasid dynasty and it
ends with the Mongol invasion

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in the middle of the 13th
century right over here.

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There are scientists like Al-Kwarizmi.

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And Al-Kwarizmi is a Persian mathematician

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and physicist.

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And he's famous for being
the father of algebra.

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The word algebra that we now have today

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the subject you can learn a
lot about on (mumbling) Academy

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it comes from the Arabic word al-jabr

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and his book al-Kitab al-mukhtasar

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fi hisab al-jabr

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wal-muqabala

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which literally means, and
those of you who might speak

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Arabic, or Persian, or even Hindi

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or who might recognize Kitab as book.

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And then hisab is calculation.

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And al-jabr is an operation of completion

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and it's essentially it's
one of the operations

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we now do in algebra where you're doing

00:04:19.268 --> 00:04:21.545
the same thing to both
sides of the equation

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Balancing is also a
very similar operation.

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He also brought the Indian number system

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or the Hindu numerals.

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He brought them to the Islamic empire.

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And that was really the
bridge to bringing it

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to the west.

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Famously Pope Sylvester the second

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he was educated in Catalonia

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with the point of acquiring knowledge

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that was gained from the Arabs.

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Remember, the Arabs were in control

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over the Islamic empires.

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It was not the Abbasids

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it was actually the
remnants of the Umayyads

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who were in control of Spain at the time.

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But because of that,
this area was considered

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a center of learning.

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And Pope Sylvester, who
got his education there,

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he's the one that is
often given credit for

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being one of the first to introduce the

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decimal numeral system.

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This Hindu Arabic decimal system

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that we now use for our numeric system

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as opposed to something
like Roman Numerals.

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Well another very
interesting thing is not only

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the word algebra comes from al-jabr

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but the word algorithm is literally

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comes from his name.

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The name Al-Kwarizmi, Al-Kwarizmi in Latin

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they pronounce as algarithme.

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So other significant contributors to

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the science of all of human civilization

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are people like al-Marwazi.

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Al-Marwazi, once again, in Baghdad.

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And he would have been a contemporary

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of al-Kwarizmi.

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And he, if you've ever taken trigonometry,

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or if you're about to take trigonometry,

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he is accredited with coming up with

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the core trigonometric functions.

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We're talking about sine, cosine.

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Tangent and cotangent

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it might have been Marwazi or it might

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have been another mathematician

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named al-Buzjani who came

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a little bit after, or a lot

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depending on a human scale,

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but was also based in Baghdad.

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And together, they came up with the six

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the six trigonometric functions.

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They weren't contemporaries of each other

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but they both made
significant contributions

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to what we now call trigonometry.

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Including many of the
trigonometric identities

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that we now learn in high school.

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Now you also have
physicists, mathematicians,

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astronomers,

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like Alhazon.

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And he is credited as
getting one of the more

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sophisticated views of how
light and vision works.

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These are some quotes from Alhazon.

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From each point of every
color body illuminated

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by any light issue light
and color along every

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straight line that can
be drawn from that point.

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This is a fairly sophisticated
view of how light

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actually works.

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And he's also credited with
using and understanding

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the scientific method

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several hundred years before
the Renaissance in Europe.

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The duty of a man, the duty
of the man who investigates

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the writing of scientists.

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If learning the truth is his goal

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is to make himself an
enemy of all that he reads

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and attack it from every side.

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He should also suspect
himself as he performs

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his critical examination of it

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so that he may avoid falling
into either prejudice

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or leniency.

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And now another very
famous poet philosopher

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mathematician poly math of the time

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was Omar Khayyan.

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And in the west, he's most
famous for his poetry.

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Most famously the work of the (mumbling)

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the translation by Fitzgerald.

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But he was also a significant philosopher

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mathematician.

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This is a picture of some
of his work right over here.

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You can see that he did
his work in the 11th

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and the 12th centuries.

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And he did it from (mumbling).

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But he investigated Pascal's Triangle

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and the binomial theorem.

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And keep in mind, this was over 500 years

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before Pascal.

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So maybe it should actually be called

00:08:21.402 --> 00:08:23.163
Khayyam's Triangle.

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And just to get a sense of
his poetry, or a sense of

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the (mumbling) in general,
which I encourage you to

00:08:27.949 --> 00:08:28.937
look up and read.

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And this is at least
Fitzgerald's translation of it.

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And that inverted bowl we call the sky

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where under crawling
cooped we live and die.

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Lift not they hands to it for help

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for it rolls impotently on

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as thou or I.

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So as you can imagine, this Islamic world

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these empires between the eighth

00:08:53.912 --> 00:08:56.584
and 13th centuries, it was
actually a very powerful

00:08:56.584 --> 00:08:58.322
bridge of human knowledge

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taking knowledge from
the Indians, the Chinese,

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the Ancient Greeks, and providing a bridge

00:09:02.736 --> 00:09:05.711
during the Dark Ages in Europe.

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And get a sense of that, we have some text

00:09:08.230 --> 00:09:11.511
from some historians on that time period.

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This is some text from

00:09:13.986 --> 00:09:16.188
this is some text from

00:09:16.188 --> 00:09:18.656
the historian Phillip Hiti.

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And he wrote,

00:09:20.370 --> 00:09:23.073
During all the first
part of the Middle Ages

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no other people made as
important a contribution

00:09:26.128 --> 00:09:28.669
to human progress as did the Arabs.

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If we take this term to mean all those

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whose mother tongue was Arabic

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and not merely those living
in the Arabian peninsula.

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For centuries, Arabic was
a language of learning,

00:09:39.465 --> 00:09:41.652
culture, and intellectual progress

00:09:41.652 --> 00:09:43.990
for the whole of the civilized world

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with the exception of the Far East.

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From the ninth to the 12th
century, there were more

00:09:49.125 --> 00:09:51.959
philosophical medical historical religious

00:09:51.959 --> 00:09:54.271
astronomical and geographical works

00:09:54.271 --> 00:09:58.156
written in Arabic than in
any other human tongue.

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And we also have a frame,
a point of view from

00:10:01.975 --> 00:10:05.498
Bertrand Russell in his
History of Western Philosophy

00:10:05.498 --> 00:10:06.763
who wrote,

00:10:06.763 --> 00:10:09.584
Our use of the phrase the Dark Ages

00:10:09.584 --> 00:10:12.064
to cover the period from 699

00:10:12.064 --> 00:10:14.906
to 1000 marks our undue concentration

00:10:14.906 --> 00:10:16.377
on Western Europe.

00:10:16.377 --> 00:10:19.268
In China, this period
includes the time of the

00:10:19.268 --> 00:10:22.989
Tang dynasty, the greatest
age of Chinese poetry.

00:10:22.989 --> 00:10:25.638
From India to Spain, the
brilliant civilization

00:10:25.638 --> 00:10:27.096
of Islam flourished.

00:10:27.096 --> 00:10:29.796
What was lost to Christendom at this time

00:10:29.796 --> 00:10:34.228
was not lost to civilization,
but quite the contrary.

00:10:34.228 --> 00:10:37.922
To us it seems that Western
European civilization

00:10:37.922 --> 00:10:40.005
is civilization, but this

00:10:41.251 --> 00:10:42.668
is a narrow view.


Spread of Islam part 3

WEBVTT
Kind: captions
Language: en

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- [Instructor] Other
videos we have talked about

00:00:02.536 --> 00:00:05.084
the early history of Islam,

00:00:05.084 --> 00:00:09.053
which really revolves
around the life of Mohammed.

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Mohammed, as we talked about,
was born roughly in 570

00:00:13.824 --> 00:00:15.157
and dies in 632.

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On this timeline here, the
white period is before,

00:00:20.615 --> 00:00:21.942
according to Muslim traditions,

00:00:21.942 --> 00:00:24.612
that he started having
the revelations from God,

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and the brown period is when
he's having these revelations

00:00:27.498 --> 00:00:29.514
and he's starting to be the leader

00:00:29.514 --> 00:00:33.015
of this nascent Muslim community.

00:00:33.015 --> 00:00:35.625
Now what we see here in this dark brown

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is what was in control
of this Muslim community

00:00:38.925 --> 00:00:41.104
at the time of Mohammed's death.

00:00:41.104 --> 00:00:44.450
You see even by that
period they had control

00:00:44.450 --> 00:00:47.603
of a good chunk of the Arabian Peninsula.

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What's particularly surprising is how fast

00:00:50.190 --> 00:00:53.070
Islam spread shortly after that.

00:00:53.070 --> 00:00:55.551
The next period, after Mohammed dies,

00:00:55.551 --> 00:00:59.508
the leadership of the
community, of the ummah,

00:00:59.508 --> 00:01:01.820
goes to the kalifs, and
this actually becomes

00:01:01.820 --> 00:01:03.831
a contentious issue that we'll talk about

00:01:03.831 --> 00:01:04.920
in other videos.

00:01:04.920 --> 00:01:07.120
It's the seed of the eventual schism

00:01:07.120 --> 00:01:09.293
between the Sunis and the Shias.

00:01:09.293 --> 00:01:11.357
But this next period, the Rashidun,

00:01:11.357 --> 00:01:13.058
or the Rightly Guided Kalifs,

00:01:13.058 --> 00:01:16.336
kalif means successors,
essentially successors to Mohammed,

00:01:16.336 --> 00:01:20.757
under these four kalifs,
you see Islam spread

00:01:20.757 --> 00:01:24.154
from as far west as Tunesia and Egypt,

00:01:24.154 --> 00:01:26.571
all the way through Persia.

00:01:26.571 --> 00:01:28.527
Keep in mind, this is spreading,

00:01:28.527 --> 00:01:31.661
overtaking, conquering,
what used to be controlled

00:01:31.661 --> 00:01:33.779
by very powerful empires,

00:01:33.779 --> 00:01:37.006
the Byzantine Empire,
or Eastern Roman Empire,

00:01:37.006 --> 00:01:39.186
taking territory from them here,

00:01:39.186 --> 00:01:43.345
and then Sasanid Persia,
taking territory from them.

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This is less than 30 years.

00:01:46.140 --> 00:01:47.789
Then it spreads even more.

00:01:47.789 --> 00:01:50.610
During the next caliphate,
which is now dynastic,

00:01:50.610 --> 00:01:54.777
the Umayyad Caliphate, by
the end of that at 750 CE,

00:01:55.844 --> 00:01:58.926
you see Islam has now spread or conquered

00:01:58.926 --> 00:02:01.246
from modern-day Spain and Portugal,

00:02:01.246 --> 00:02:04.996
all the way to modern-day
India and Pakistan.

00:02:06.398 --> 00:02:08.108
We could continue this narrative,

00:02:08.108 --> 00:02:11.111
and we will continue to talk
about it in future videos.

00:02:11.111 --> 00:02:13.305
But what's really
interesting is to think about

00:02:13.305 --> 00:02:18.036
how and why it was able
to spread this rapidly.

00:02:18.036 --> 00:02:19.891
There's few instances in history

00:02:19.891 --> 00:02:23.932
where we see this type of
an empire form this quickly.

00:02:23.932 --> 00:02:27.963
To get some context on
that, we have this text here

00:02:27.963 --> 00:02:31.469
from the American
historian Ira Lapidus' book

00:02:31.469 --> 00:02:34.634
Islamic Societies to
the Nineteenth Century.

00:02:34.634 --> 00:02:38.154
Ira Lapidus writes,
"The expansion of Islam

00:02:38.154 --> 00:02:40.580
"involved different factors
in different regions.

00:02:40.580 --> 00:02:43.292
"In North Africa, Anatolia,
the Balkans, and India,"

00:02:43.292 --> 00:02:45.459
so these are regions that we
aren't showing on this map,

00:02:45.459 --> 00:02:48.718
those happened later on
outside of the period

00:02:48.718 --> 00:02:50.235
depicted in this map,

00:02:50.235 --> 00:02:53.588
"it was carried out by nomadic
Arab or Turkish conquerors."

00:02:53.588 --> 00:02:56.196
That is a similar form, method
that we're talking about

00:02:56.196 --> 00:02:57.480
though in this map.

00:02:57.480 --> 00:02:59.278
"In the Indian Ocean and West Africa,

00:02:59.278 --> 00:03:02.160
"it spread by peaceful
contacts among merchants

00:03:02.160 --> 00:03:04.206
"or through the preaching of missionaries.

00:03:04.206 --> 00:03:06.149
"In some cases, the diffusion of Islam

00:03:06.149 --> 00:03:09.496
"depended on its adoption
by local ruling families.

00:03:09.496 --> 00:03:12.474
"In others, it appealed to
urban classes of the population,

00:03:12.474 --> 00:03:14.346
"or tribal communities.

00:03:14.346 --> 00:03:17.261
"The question of why
people convert to Islam

00:03:17.261 --> 00:03:20.145
"has always generated intense feeling.

00:03:20.145 --> 00:03:22.851
"Earlier generations of European scholars

00:03:22.851 --> 00:03:25.056
"believed that conversion to Islam

00:03:25.056 --> 00:03:27.763
"were made by the point of the sword,

00:03:27.763 --> 00:03:30.255
"and that conquered people's
were given the choice

00:03:30.255 --> 00:03:31.794
"of conversion or death."

00:03:31.794 --> 00:03:35.401
So according to Ira Lapidus,
these early European scholars

00:03:35.401 --> 00:03:39.124
viewed it analogous to things
like the Spanish Inquisition,

00:03:39.124 --> 00:03:41.858
or some aspects of the Crusades,

00:03:41.858 --> 00:03:44.063
or some of what we saw in the New World

00:03:44.063 --> 00:03:48.160
with the conquistadors, where
it really was convert or die.

00:03:48.160 --> 00:03:49.560
But according to Lapidus,

00:03:49.560 --> 00:03:52.003
"It is now apparent that
conversion by force,

00:03:52.003 --> 00:03:54.058
"while not unknown in Muslim countries,"

00:03:54.058 --> 00:03:57.067
so there was some forced conversion,

00:03:57.067 --> 00:03:59.611
but according to Lapidus
was, in fact, rare,

00:03:59.611 --> 00:04:02.170
"Muslim conquerors
ordinarily wished to dominate

00:04:02.170 --> 00:04:05.262
"rather than convert, and most conversions

00:04:05.262 --> 00:04:07.495
"to Islam were voluntary.

00:04:07.495 --> 00:04:10.140
"In most cases, worldly
and spiritual motives

00:04:10.140 --> 00:04:12.119
"for conversion blended together."

00:04:12.119 --> 00:04:16.062
Other sources I've looked
at do hint at these

00:04:16.062 --> 00:04:19.036
early caliphates weren't that
interested in conversion.

00:04:19.036 --> 00:04:23.223
They were clearly Muslim, and
they were also Arab dominated,

00:04:23.223 --> 00:04:26.983
and they liked having this
elite Arab Muslim ruling class

00:04:26.983 --> 00:04:28.199
and they weren't that interested

00:04:28.199 --> 00:04:31.030
in spreading their religion.

00:04:31.030 --> 00:04:34.697
Only when we get into
the Abbasid Caliphate,

00:04:35.704 --> 00:04:37.863
where it becomes more multicultural

00:04:37.863 --> 00:04:40.731
and more Muslim and less Arab focused,

00:04:40.731 --> 00:04:43.983
that you start to have
more and more conversions.

00:04:43.983 --> 00:04:46.365
The sources I've seen have, by the end

00:04:46.365 --> 00:04:50.229
of the Omayyad dynasty, only about 10%-30%

00:04:50.229 --> 00:04:53.445
of the conquered people convert to Islam,

00:04:53.445 --> 00:04:55.861
but much more convert during what's often

00:04:55.861 --> 00:04:57.524
referred to as the Golden Age of Islam,

00:04:57.524 --> 00:04:59.440
when Islam is collecting the works

00:04:59.440 --> 00:05:02.424
of the ancient Greeks, and
the Chinese, and the Hindus,

00:05:02.424 --> 00:05:04.982
and getting scholars
from all around the world

00:05:04.982 --> 00:05:07.149
under the Abbasid dynasty.

00:05:08.708 --> 00:05:13.026
Now, when Lapidus talks
about in most cases worldly

00:05:13.026 --> 00:05:16.456
and spiritual motives for
conversion blended together,

00:05:16.456 --> 00:05:17.816
he's referring to these ideas that maybe

00:05:17.816 --> 00:05:20.701
for some people it just appealed to them.

00:05:20.701 --> 00:05:22.796
You have to remember,
people weren't going from

00:05:22.796 --> 00:05:25.961
being independent to being
subjugated in most cases.

00:05:25.961 --> 00:05:28.197
Even before the conquest of Islam,

00:05:28.197 --> 00:05:31.032
they were probably subjugated by a king

00:05:31.032 --> 00:05:33.591
or part of an empire
like the Byzantine Empire

00:05:33.591 --> 00:05:34.988
or the Persian Empire.

00:05:34.988 --> 00:05:37.784
So they're really switching
from one conqueror to another,

00:05:37.784 --> 00:05:39.473
and oftentimes people are hopeful

00:05:39.473 --> 00:05:41.906
that the new conqueror might
be better than the last.

00:05:41.906 --> 00:05:43.935
Oftentimes they're proven wrong.

00:05:43.935 --> 00:05:46.552
Sometimes it might actually be the case.

00:05:46.552 --> 00:05:48.363
There might have been some support

00:05:48.363 --> 00:05:51.023
that allowed it to spread this quickly.

00:05:51.023 --> 00:05:52.938
There's also worldly motives.

00:05:52.938 --> 00:05:56.027
If there's a Muslim ruling class,

00:05:56.027 --> 00:05:58.459
and if you want to be associated
with that ruling class,

00:05:58.459 --> 00:06:00.361
that might be a worldly motivation

00:06:00.361 --> 00:06:03.486
in order to actually convert.

00:06:03.486 --> 00:06:05.218
Now the other thing that we do know

00:06:05.218 --> 00:06:07.754
about these early Muslim empires,

00:06:07.754 --> 00:06:09.054
and many of the Muslim empires,

00:06:09.054 --> 00:06:13.225
is they did have this
notion of dhimmi status.

00:06:13.225 --> 00:06:17.688
Dhimmi is referring to the
idea of protected persons.

00:06:17.688 --> 00:06:20.617
It's often referred to
as people of the book,

00:06:20.617 --> 00:06:24.367
but it included Jews,
Christians, that Islam,

00:06:25.579 --> 00:06:27.112
according to Islamic tradition follows

00:06:27.112 --> 00:06:28.705
in the same tradition of.

00:06:28.705 --> 00:06:32.007
But then when you eventually
have Muslim conquest of India

00:06:32.007 --> 00:06:35.090
included Hindus and Buddists as well,

00:06:39.250 --> 00:06:41.042
and it also included Zoroastrians,

00:06:41.042 --> 00:06:45.056
who the early Muslims
considered to be monotheistic.

00:06:45.056 --> 00:06:46.683
The idea of dhimmi status is that

00:06:46.683 --> 00:06:48.141
they would have protected rights,

00:06:48.141 --> 00:06:50.396
they would have the same
property contract rights,

00:06:50.396 --> 00:06:52.741
but different political rights.

00:06:52.741 --> 00:06:54.903
The Muslim ruling class definitely had

00:06:54.903 --> 00:06:56.558
better political rights.

00:06:56.558 --> 00:06:57.996
They would pay a different tax

00:06:57.996 --> 00:07:00.982
than what the Muslims actually paid.

00:07:00.982 --> 00:07:04.821
Now in order to get context
from a religious point of view,

00:07:04.821 --> 00:07:08.133
you can look at some of the
religious texts of Islam,

00:07:08.133 --> 00:07:11.523
especially the Koran, and even the Hadith,

00:07:11.523 --> 00:07:13.689
which are the secondhand accounts

00:07:13.689 --> 00:07:17.106
of the life and practices of Mohammed.

00:07:17.106 --> 00:07:20.318
There you get an interesting perspective.

00:07:20.318 --> 00:07:24.047
On the side of religious tolerance,

00:07:24.047 --> 00:07:26.380
you have excerpts like this.

00:07:27.317 --> 00:07:28.555
"There shall be no compulsion

00:07:28.555 --> 00:07:30.610
"in acceptance of the religion."

00:07:30.610 --> 00:07:33.283
"Unto you your religion
and unto my religion."

00:07:33.283 --> 00:07:34.901
From and ethnic point of view,

00:07:34.901 --> 00:07:39.078
there also seems to be a
sense of nonsuperiority

00:07:39.078 --> 00:07:41.008
of one ethnicity over another.

00:07:41.008 --> 00:07:42.474
"Indeed, there is no superiority

00:07:42.474 --> 00:07:46.304
"of an Arab over a non-Arab,
nor of a non-Arab over an Arab,

00:07:46.304 --> 00:07:49.849
"nor or a white over a black,
nor a black over a white,

00:07:49.849 --> 00:07:51.730
"except by piety towards God."

00:07:51.730 --> 00:07:54.054
This is from Mohammed's farewell sermon.

00:07:54.054 --> 00:07:55.676
This is given by the Hadith,

00:07:55.676 --> 00:07:57.859
The Life and Sayings of Mohammed.

00:07:57.859 --> 00:08:00.379
Now on the other hand,
there definitely are

00:08:00.379 --> 00:08:03.261
more militant portions of the Koran.

00:08:03.261 --> 00:08:06.939
One of the most quoted
excerpts is this one.

00:08:06.939 --> 00:08:09.800
"And fight in the way of
God those who fight you,

00:08:09.800 --> 00:08:11.651
"but transgress not the limits.

00:08:11.651 --> 00:08:14.334
"Truly God likes not the transgressors.

00:08:14.334 --> 00:08:16.855
"And kill them wherever you overtake them

00:08:16.855 --> 00:08:19.731
"and expel them from wherever
they have expelled you,

00:08:19.731 --> 00:08:22.249
"and persecution is worse than killing.

00:08:22.249 --> 00:08:24.502
"And do not fight them
at the sacred mosque

00:08:24.502 --> 00:08:26.037
"until they fight you there.

00:08:26.037 --> 00:08:28.532
"But if they fight you, then kill them.

00:08:28.532 --> 00:08:31.325
"Such is the recompense
of the disbelievers.

00:08:31.325 --> 00:08:33.244
"And if they cease, then indeed

00:08:33.244 --> 00:08:35.242
"God is forgiving and merciful.

00:08:35.242 --> 00:08:37.469
"Fight them until there is no persecution

00:08:37.469 --> 00:08:40.349
"and until worship is
acknowledged to be for God.

00:08:40.349 --> 00:08:42.913
"But if they cease, then there is to be

00:08:42.913 --> 00:08:47.314
"no aggression except
against the oppressors."

00:08:47.314 --> 00:08:49.133
So a critical view of this is saying,

00:08:49.133 --> 00:08:53.300
look, this is clearly
advocating to kill other people,

00:08:54.887 --> 00:08:59.673
and fight those who are
considered to be disbelievers.

00:08:59.673 --> 00:09:02.012
That's clearly a critical view of this.

00:09:02.012 --> 00:09:05.594
You will not see this type
of language, for example,

00:09:05.594 --> 00:09:09.427
in more pacifist notions
of, say, the Gospels.

00:09:11.276 --> 00:09:15.164
It's definitely not the
modern notion that we have

00:09:15.164 --> 00:09:17.718
of passive resistance,
or peaceful resistance,

00:09:17.718 --> 00:09:22.118
and the notion of a Gandhi
or a Martin Luther King.

00:09:22.118 --> 00:09:23.817
Now those who would defend

00:09:23.817 --> 00:09:25.925
or see a little bit more nuance here,

00:09:25.925 --> 00:09:27.679
would say, look, you've got to,

00:09:27.679 --> 00:09:31.539
this is not talking about
killing disbelievers arbitrarily.

00:09:31.539 --> 00:09:35.471
This is talking about killing
those who are persecuting you.

00:09:35.471 --> 00:09:38.909
They would say, look, this
revelation is believed,

00:09:38.909 --> 00:09:40.217
according to Islamic tradition,

00:09:40.217 --> 00:09:43.353
to have come down when the Muslims

00:09:43.353 --> 00:09:46.506
were actively being persecuted
by Mohammed's tribe,

00:09:46.506 --> 00:09:47.411
the Quraysh.

00:09:47.411 --> 00:09:48.244
They were in Medina.

00:09:48.244 --> 00:09:49.655
They were essentially in exile.

00:09:49.655 --> 00:09:52.301
They were in fear for their
lives, Mohammed's own life.

00:09:52.301 --> 00:09:54.431
The Quraysh had attempted to kill him.

00:09:54.431 --> 00:09:56.279
They were torturing and killing

00:09:56.279 --> 00:09:57.742
that early Muslim community.

00:09:57.742 --> 00:09:59.698
In that context they're saying,

00:09:59.698 --> 00:10:02.542
"And fight the way of
God those who fight you."

00:10:02.542 --> 00:10:04.054
So it's really out of defense,

00:10:04.054 --> 00:10:05.679
trying not to be persecuted.

00:10:05.679 --> 00:10:07.104
"But transgress not the limits."

00:10:07.104 --> 00:10:09.535
Even there there are rules of law here,

00:10:09.535 --> 00:10:11.448
or rules of engagement.

00:10:11.448 --> 00:10:12.946
"And kill them wherever you overtake them

00:10:12.946 --> 00:10:15.518
"and expel them from wherever
they have expelled you,

00:10:15.518 --> 00:10:19.161
"and persecution is worse than killing."

00:10:19.161 --> 00:10:22.005
So this is creating a moral hierarchy

00:10:22.005 --> 00:10:25.594
that is very debatable,
especially in modern times.

00:10:25.594 --> 00:10:28.520
Is persecution worse than killing?

00:10:28.520 --> 00:10:30.206
"And do not fight them
at the sacred mosque."

00:10:30.206 --> 00:10:33.001
This really seems to be
referring to the Quraysh,

00:10:33.001 --> 00:10:35.032
because remember they're fighting over

00:10:35.032 --> 00:10:38.212
this notion of what even should
happen at the sacred mosque.

00:10:38.212 --> 00:10:39.669
"Until they fight you there.

00:10:39.669 --> 00:10:41.598
"But if they fight you, then kill them.

00:10:41.598 --> 00:10:43.609
"Such is the recompense
for the disbelievers.

00:10:43.609 --> 00:10:45.714
"And if they cease, then indeed God

00:10:45.714 --> 00:10:47.434
"is forgiving and merciful."

00:10:47.434 --> 00:10:49.775
So to some degree, those who would see

00:10:49.775 --> 00:10:52.100
the nuance in this passage,
they say, hey look,

00:10:52.100 --> 00:10:55.076
this is talking about killing
those who persecute you,

00:10:55.076 --> 00:10:58.311
but it actually seems to be a
little bit more conciliatory.

00:10:58.311 --> 00:11:01.770
Remember, the Koran is,
according to Islamic tradition,

00:11:01.770 --> 00:11:04.169
built on the traditions
of the Old Testament

00:11:04.169 --> 00:11:05.579
and on Christian traditions.

00:11:05.579 --> 00:11:07.785
Especially relative to the Old Testament,

00:11:07.785 --> 00:11:09.523
which tends to be much more absolute

00:11:09.523 --> 00:11:11.967
when someone is disliked by God,

00:11:11.967 --> 00:11:16.135
whole cities or peoples
are destroyed or killed,

00:11:16.135 --> 00:11:19.651
or God might command his
prophets and the leadership

00:11:19.651 --> 00:11:21.542
to kill other people just because

00:11:21.542 --> 00:11:23.529
they disbelieve God in the Old Testament.

00:11:23.529 --> 00:11:27.111
People who would defend this
passage or see nuance here

00:11:27.111 --> 00:11:29.388
says, look, this is about being persecuted

00:11:29.388 --> 00:11:33.513
and fighting persecution,
and if those persecutors stop

00:11:33.513 --> 00:11:35.725
then don't seek revenge.

00:11:35.725 --> 00:11:36.908
"And if they cease then indeed God

00:11:36.908 --> 00:11:38.732
"is forgiving and merciful.

00:11:38.732 --> 00:11:40.118
"And there is to be no aggression

00:11:40.118 --> 00:11:43.001
"except against the oppressors."

00:11:43.001 --> 00:11:45.388
I'll leave it to you to decide.

00:11:45.388 --> 00:11:47.921
I encourage you to look up
your own primary resources.

00:11:47.921 --> 00:11:49.585
Look up different translations.

00:11:49.585 --> 00:11:52.776
One of the tricky things
of not just the Koran,

00:11:52.776 --> 00:11:54.704
but including the Bible, which is believed

00:11:54.704 --> 00:11:56.604
to first be written in Aramaic,

00:11:56.604 --> 00:11:59.765
or the Old Testament, the
Torah, written in Hebrew,

00:11:59.765 --> 00:12:01.869
is that the translation itself can also

00:12:01.869 --> 00:12:03.427
give you various nuance.

00:12:03.427 --> 00:12:05.490
But make your own decisions about

00:12:05.490 --> 00:12:08.481
what you think is, or your own judgments

00:12:08.481 --> 00:12:10.867
of what we've talked about in this video.


Beginnings of Islam part 2

WEBVTT
Kind: captions
Language: en

00:00:00.000 --> 00:00:02.420
- [Lecturer] Where we left
off in the last video,

00:00:02.420 --> 00:00:06.587
we saw a Muhammed being
born into a tribal Arabia.

00:00:08.194 --> 00:00:11.454
He's born into a powerful
tribe, the Quraysh,

00:00:11.454 --> 00:00:14.436
who are in control of Mecca.

00:00:14.436 --> 00:00:16.504
But his early life is difficult.

00:00:16.504 --> 00:00:18.274
His mother dies when he's six.

00:00:18.274 --> 00:00:20.521
His grandfather who's taken charge of him,

00:00:20.521 --> 00:00:22.831
dies when he's eight years old.

00:00:22.831 --> 00:00:25.012
But he's able to, under
the care of his uncle,

00:00:25.012 --> 00:00:26.608
become a merchant.

00:00:26.608 --> 00:00:30.775
And at the age of 25, he marries
a wealthy merchant widower

00:00:32.555 --> 00:00:36.370
named Khadija who is 15 years his senior.

00:00:36.370 --> 00:00:40.537
Then we saw at age 40 in 610,
while meditating in a mountain

00:00:42.443 --> 00:00:45.826
outside of Mecca, he receives
the first revelations

00:00:45.826 --> 00:00:49.723
of the Quran, according
to Islamic tradition.

00:00:49.723 --> 00:00:52.850
And he's skeptical of it at
first, but he's reassured.

00:00:52.850 --> 00:00:57.052
And then he soon receives
many more revelations.

00:00:57.052 --> 00:01:00.658
And within roughly three
years, he starts to preach

00:01:00.658 --> 00:01:02.158
those revelations.

00:01:03.147 --> 00:01:05.380
Now as we mentioned in that last video,

00:01:05.380 --> 00:01:09.003
what he was preaching did not
sit well with his own tribe,

00:01:09.003 --> 00:01:11.586
those who ruled Mecca, the Quraysh.

00:01:11.586 --> 00:01:15.489
He was preaching a mono theistic tradition

00:01:15.489 --> 00:01:19.009
based on Judaism and Christianity.

00:01:19.009 --> 00:01:21.788
He was preaching that
there's no God but God.

00:01:21.788 --> 00:01:26.582
But Mecca's power, it's
economy was based on people

00:01:26.582 --> 00:01:31.553
making pilgrimages there to
worship the idols at the Kaaba.

00:01:31.553 --> 00:01:35.308
So the Quraysh did not
like Muhammed's revelations

00:01:35.308 --> 00:01:37.745
and they did not like these early Muslims,

00:01:37.745 --> 00:01:39.298
and they persecuted them.

00:01:39.298 --> 00:01:41.766
They killed them, they tortured them,

00:01:41.766 --> 00:01:45.933
and we saw in 615 the
migration of some of Muhammed's

00:01:48.457 --> 00:01:52.604
followers to Abyssinia,
the Kingdom of Aksum,

00:01:52.604 --> 00:01:54.919
modern day Eritrea and Ethiopia,

00:01:54.919 --> 00:01:57.527
to escape some of that persecution.

00:01:57.527 --> 00:01:59.406
Things got worse for Muhammed.

00:01:59.406 --> 00:02:02.220
We saw in that last video,
the death of his first wife

00:02:02.220 --> 00:02:06.010
and up to that point, his only wife.

00:02:06.010 --> 00:02:09.384
And this is where we start
to see a bit of turning point

00:02:09.384 --> 00:02:11.967
for Muhammed and his followers.

00:02:13.186 --> 00:02:17.750
In 620 and this is according
to Muslim traditions,

00:02:17.750 --> 00:02:20.079
there isn't historical evidence for this,

00:02:20.079 --> 00:02:23.011
and this is one of the
more metaphysical events

00:02:23.011 --> 00:02:25.478
that we'll talk about in this narrative.

00:02:25.478 --> 00:02:27.429
But according to the Islamic faith,

00:02:27.429 --> 00:02:31.262
in 620 Muhammed has a
night journey from Mecca

00:02:32.966 --> 00:02:36.711
to the farthest mosque,
which today is believed

00:02:36.711 --> 00:02:39.873
by many Muslims to be the Al-Aqsa mosque,

00:02:39.873 --> 00:02:42.804
which was built later in Jerusalem.

00:02:42.804 --> 00:02:44.387
So right over here.

00:02:49.083 --> 00:02:52.326
So a night journey according
to the Muslim faith,

00:02:52.326 --> 00:02:55.395
to Jerusalem where he
ascended with Gabriel

00:02:55.395 --> 00:02:57.978
to the heavens and he conversed

00:02:58.885 --> 00:03:01.635
with some of the prophets of old.

00:03:02.605 --> 00:03:04.843
And once again, this is
clearly a metaphysical thing,

00:03:04.843 --> 00:03:09.509
but it's significant
event in the Muslim faith.

00:03:09.509 --> 00:03:13.093
Now the Quraysh continued
to persecute Muhammed

00:03:13.093 --> 00:03:15.652
and the early Muslims in Mecca.

00:03:15.652 --> 00:03:19.181
We have some of them that are
now in the Kingdom of Aksum.

00:03:19.181 --> 00:03:22.560
And Muhammed learns that
there's a community,

00:03:22.560 --> 00:03:27.018
a growing community of Muslims
in the town of Yathrib,

00:03:27.018 --> 00:03:31.307
who are starting to follow
Muhammed or his revelations.

00:03:31.307 --> 00:03:34.115
And they come to him and they invite him

00:03:34.115 --> 00:03:37.329
to come to Yathrib because
there's actually a lot

00:03:37.329 --> 00:03:40.662
of fragmentation, there's waring tribes.

00:03:41.579 --> 00:03:45.942
And they're seeking an outsider
to help bring some peace

00:03:45.942 --> 00:03:48.424
and authority to this place
where there is already

00:03:48.424 --> 00:03:51.283
a burgeoning Muslim community.

00:03:51.283 --> 00:03:54.616
So in 622, you have the famous migration

00:03:55.775 --> 00:03:59.192
of Muhammed and his followers to Yathrib.

00:04:00.394 --> 00:04:02.472
Which is renamed Medina.

00:04:02.472 --> 00:04:04.932
And Medina literally means The City.

00:04:04.932 --> 00:04:08.059
And from then on it
really becomes the base

00:04:08.059 --> 00:04:10.892
of Muhammed and the early Muslims.

00:04:12.652 --> 00:04:14.793
And Muhammed, once he's in Medina,

00:04:14.793 --> 00:04:17.781
he is no longer just a prophet.

00:04:17.781 --> 00:04:21.563
He isn't just continuing
to have his revelations

00:04:21.563 --> 00:04:23.029
according to Islamic tradition.

00:04:23.029 --> 00:04:27.252
But he essentially rules
over Medina, and governs it.

00:04:27.252 --> 00:04:31.335
So he's starting to become
both a political ruler

00:04:32.259 --> 00:04:34.687
and a spiritual ruler.

00:04:34.687 --> 00:04:38.627
Now the Quraysh in Mecca
are still not happy.

00:04:38.627 --> 00:04:40.654
Because Muhammed is continuing to preach,

00:04:40.654 --> 00:04:43.998
and he's continuing to get
more and more followers.

00:04:43.998 --> 00:04:47.481
And so you start having, at
first, a series of skirmishes

00:04:47.481 --> 00:04:49.935
between the armies of the Quraysh,

00:04:49.935 --> 00:04:51.956
or the members of the Quraysh,

00:04:51.956 --> 00:04:53.636
and some of the early Muslims.

00:04:53.636 --> 00:04:55.457
But these skirmishes eventually

00:04:55.457 --> 00:04:57.874
emerge into full on conflict.

00:04:58.875 --> 00:05:02.459
And here are some of
the significant battles

00:05:02.459 --> 00:05:05.295
that occurred between the Quraysh tribe,

00:05:05.295 --> 00:05:07.749
remember that's Muhammed's own tribe,

00:05:07.749 --> 00:05:11.456
and the early Muslims, the
early followers of Muhammed

00:05:11.456 --> 00:05:13.546
and his revelations.

00:05:13.546 --> 00:05:18.459
So most famously perhaps,
you have the Battle of Badr.

00:05:18.459 --> 00:05:21.739
Because this is the first time
that you have a significant

00:05:21.739 --> 00:05:24.656
confrontation between a very small,

00:05:24.656 --> 00:05:27.210
you wouldn't even necessarily
call this an army,

00:05:27.210 --> 00:05:30.556
a small group of Muslims,
roughly a little over 300

00:05:30.556 --> 00:05:33.132
according to Muslim tradition,

00:05:33.132 --> 00:05:37.875
versus 900 or a little over
900 on the Quraysh side.

00:05:37.875 --> 00:05:40.967
And the Muslims are
outnumbered three to one.

00:05:40.967 --> 00:05:43.369
But this results in a Muslim victory.

00:05:43.369 --> 00:05:45.917
And so you can imagine the
early Muslims start to see

00:05:45.917 --> 00:05:47.149
this as a turning tide.

00:05:47.149 --> 00:05:49.827
They were able to defeat
the powerful Quraysh tribe.

00:05:49.827 --> 00:05:52.512
Now the Quraysh weren't happy with that.

00:05:52.512 --> 00:05:56.044
And roughly a year later
you have another battle

00:05:56.044 --> 00:05:58.711
outside of Medina on Mount Uhud.

00:06:00.849 --> 00:06:03.659
And once again, the Muslims,
which are now larger,

00:06:03.659 --> 00:06:05.518
but they continued to
be outnumbered even more

00:06:05.518 --> 00:06:08.330
than three to one, this
is closer to four to one

00:06:08.330 --> 00:06:09.312
right over here.

00:06:09.312 --> 00:06:12.479
And this results in a Quraysh victory.

00:06:13.440 --> 00:06:15.441
This is right over there.

00:06:15.441 --> 00:06:19.936
Outside, on the northern side
of what is now called Medina.

00:06:19.936 --> 00:06:23.796
But then a few years later
you have a significant battle.

00:06:23.796 --> 00:06:27.040
Where the Quraysh have
built a confederacy.

00:06:27.040 --> 00:06:30.951
And they wanna end the
teachings of Muhammed,

00:06:30.951 --> 00:06:33.288
they wanna end these
Muslims who are threatening,

00:06:33.288 --> 00:06:37.663
who's preachings are
threatening the pilgrimage,

00:06:37.663 --> 00:06:41.323
the legitimacy of the
Quraysh tribe in Mecca.

00:06:41.323 --> 00:06:45.695
And so they laid siege
to the city of Medina.

00:06:45.695 --> 00:06:49.259
And as a defensive measure,
the Muslims in Medina,

00:06:49.259 --> 00:06:51.676
create a trench around the city.

00:06:51.676 --> 00:06:54.626
And that's why this is called
the Battle of the Trench.

00:06:54.626 --> 00:06:57.899
And once again, according
to Islamic tradition,

00:06:57.899 --> 00:07:01.054
the Muslims are outnumbered three to one.

00:07:01.054 --> 00:07:05.221
So this is right over here,
the Battle of the Trench.

00:07:06.330 --> 00:07:08.731
In which the Muslims are victorious.

00:07:08.731 --> 00:07:12.418
And this is a significant
blow to the legitimacy,

00:07:12.418 --> 00:07:15.822
the prestige of the Quraysh tribe.

00:07:15.822 --> 00:07:19.217
A year later, you have
the Treaty of Hudaybiyyah,

00:07:19.217 --> 00:07:22.751
between the Quraysh and the Muslims.

00:07:22.751 --> 00:07:25.384
And this is significant
because it's starting

00:07:25.384 --> 00:07:28.360
to put these early Muslims
on the same footing

00:07:28.360 --> 00:07:30.378
as the powerful Quraysh tribe.

00:07:30.378 --> 00:07:34.773
It has some allowances for the
Muslims to make pilgrimages

00:07:34.773 --> 00:07:35.856
to the Kaaba.

00:07:37.111 --> 00:07:41.278
But then as we go into 630,
there's an incident in which

00:07:42.800 --> 00:07:47.451
one tribe kills some
members of another tribe.

00:07:47.451 --> 00:07:49.940
Remember we're still in
a very tribal society.

00:07:49.940 --> 00:07:53.081
And the other tribe, the one
that had some members killed,

00:07:53.081 --> 00:07:56.507
was aligned, was friendly
with the early Muslims.

00:07:56.507 --> 00:07:59.185
So the early Muslims
did not appreciate this.

00:07:59.185 --> 00:08:01.645
They send an ultimatum to the Quraysh.

00:08:01.645 --> 00:08:06.215
And the Quraysh essentially
say well that doesn't matter,

00:08:06.215 --> 00:08:08.770
we don't really take what
you have to say seriously.

00:08:08.770 --> 00:08:11.142
And they take one of the
options of the ultimatum,

00:08:11.142 --> 00:08:15.590
which is making the Treaty
of Hudaybiyyah null and void.

00:08:15.590 --> 00:08:18.240
So now that the treaty is
not there, and once again,

00:08:18.240 --> 00:08:20.446
this is according to Muslim traditions,

00:08:20.446 --> 00:08:23.904
which are our main accounts
that we have of this time.

00:08:23.904 --> 00:08:26.821
We then have in 630, 10000 Muslims,

00:08:28.021 --> 00:08:29.550
which is a very significant number.

00:08:29.550 --> 00:08:32.164
Remember only six years ago,
we're talking about only 300

00:08:32.164 --> 00:08:34.182
Muslims in the Battle of Badr.

00:08:34.182 --> 00:08:36.932
But 10000 Muslims march on Mecca.

00:08:38.731 --> 00:08:41.682
And they're able to take
the city peacefully.

00:08:41.682 --> 00:08:45.073
And what this results in is
essentially most of the city,

00:08:45.073 --> 00:08:46.740
converting to Islam.

00:08:47.632 --> 00:08:51.007
And famously Muhammed goes into the Kaaba

00:08:51.007 --> 00:08:53.424
and destroys the idols there.

00:08:54.753 --> 00:08:56.850
And according to Islamic tradition,

00:08:56.850 --> 00:09:00.600
makes the Kaaba a center
of the Muslim faith.

00:09:01.585 --> 00:09:04.157
And it is even today.

00:09:04.157 --> 00:09:08.324
Now from that point, the
spread of Islam continues.

00:09:09.810 --> 00:09:13.370
You have Muhammed and his
armies, this green area

00:09:13.370 --> 00:09:15.441
is essentially what they
were able to conquer

00:09:15.441 --> 00:09:17.858
in the remainder of his life.

00:09:22.077 --> 00:09:25.466
He lives for another two years after

00:09:25.466 --> 00:09:28.216
the acceptance of Islam by Mecca.

00:09:30.104 --> 00:09:34.271
And they're able to conquer
most of this dark green area

00:09:36.146 --> 00:09:38.949
here and as we'll see,
shortly after his death,

00:09:38.949 --> 00:09:41.485
most of Arabia and even Persia,

00:09:41.485 --> 00:09:42.914
and within a few hundred years,

00:09:42.914 --> 00:09:46.047
a large chunk of the world were able

00:09:46.047 --> 00:09:48.877
to be conquered by these Muslim armies.


Life of Muhammad and beginnings of Islam part 1

WEBVTT
Kind: captions
Language: en

00:00:00.067 --> 00:00:01.468
- [Teacher] I'm now
going to give an overview

00:00:01.468 --> 00:00:04.514
on the beginnings of Islam.

00:00:04.514 --> 00:00:07.192
And regardless of whether you are a part

00:00:07.192 --> 00:00:11.619
of an Islamic culture, you
are a practicing Muslim,

00:00:11.619 --> 00:00:14.649
or you believe in the Islamic traditions,

00:00:14.649 --> 00:00:16.971
it's valuable to learn about
the beginnings of Islam

00:00:16.971 --> 00:00:20.984
because, today, nearly one-fourth
of the world's population

00:00:20.984 --> 00:00:22.939
either is a practicing Muslim

00:00:22.939 --> 00:00:26.272
or has grown up in an Islamic tradition.

00:00:27.629 --> 00:00:30.671
Now, the beginnings of
Islam really are centered

00:00:30.671 --> 00:00:33.046
on the life and the revelations

00:00:33.046 --> 00:00:36.429
of the Muslim prophet, Muhammad.

00:00:36.429 --> 00:00:39.471
Now, the term, Islam, means surrender

00:00:39.471 --> 00:00:42.401
and, as we'll see, a lot of
the revelations of Muhammad

00:00:42.401 --> 00:00:44.784
are about surrendering to God,

00:00:44.784 --> 00:00:48.852
about the oneness of God,
about not worshiping idols.

00:00:48.852 --> 00:00:52.314
And to put Muhammad in
perspective, on a timeline,

00:00:52.314 --> 00:00:55.621
I have other significant
biblical figures, here,

00:00:55.621 --> 00:00:57.583
and these are important
not just to get a reference

00:00:57.583 --> 00:01:00.857
towards Christianity and Judaism,

00:01:00.857 --> 00:01:03.179
but because, according
to Islamic tradition,

00:01:03.179 --> 00:01:05.789
Islam is built on top of the teachings

00:01:05.789 --> 00:01:09.956
of Abraham, or the teachings
of Moses and the Torah,

00:01:10.865 --> 00:01:13.477
and the teachings of Jesus.

00:01:13.477 --> 00:01:16.658
Muslims believe that the
Quran is the Final Testament,

00:01:16.658 --> 00:01:17.658
so to speak.

00:01:19.016 --> 00:01:20.641
To get some context,

00:01:20.641 --> 00:01:24.344
Muhammad was born is 6th Century Arabia,

00:01:24.344 --> 00:01:27.212
and 6th Century Arabia
was an interesting place.

00:01:27.212 --> 00:01:28.802
In many other videos, we've talked

00:01:28.802 --> 00:01:31.461
about various empires
around the Mediterranean,

00:01:31.461 --> 00:01:34.294
around the Mesopotamia and Persia.

00:01:36.325 --> 00:01:37.997
And even on this map,
in the time of Muhammad,

00:01:37.997 --> 00:01:39.065
you see significant empires,

00:01:39.065 --> 00:01:41.691
the Byzantine Empire,
the Eastern Roman Empire.

00:01:41.691 --> 00:01:43.619
You have Sasanid Persia.

00:01:43.619 --> 00:01:47.144
But Arabia was never really consolidated,

00:01:47.144 --> 00:01:50.515
or ruled, by a formal, or most of Arabia,

00:01:50.515 --> 00:01:54.017
by a formal government or a formal empire.

00:01:54.017 --> 00:01:56.842
The rule of law in most of Arabia,

00:01:56.842 --> 00:01:59.582
and the world in which
Muhammad was born into,

00:01:59.582 --> 00:02:03.960
was a tribal world
where you were protected

00:02:03.960 --> 00:02:06.897
by your tribe and it was really the laws

00:02:06.897 --> 00:02:11.108
of vendetta and revenge that
kept certain things in check,

00:02:11.108 --> 00:02:15.275
but also would lead to a lot
of wars and a lot of violence.

00:02:16.138 --> 00:02:18.425
And within Arabia, there were many folks

00:02:18.425 --> 00:02:21.583
who are Bedouins, who were nomadic people,

00:02:21.583 --> 00:02:23.383
who traveled through the desert

00:02:23.383 --> 00:02:28.003
allowing their livestock to
graze on whatever suitable land

00:02:28.003 --> 00:02:30.209
they found, but you
also had settled people

00:02:30.209 --> 00:02:31.800
in places like Mecca.

00:02:31.800 --> 00:02:34.437
You had people who'd settled
and started agriculture

00:02:34.437 --> 00:02:35.863
around oases.

00:02:35.863 --> 00:02:39.555
Remember, most of the Arabian
Peninsula is really desert.

00:02:39.555 --> 00:02:42.645
And, Muhammad was born into a fairly,

00:02:42.645 --> 00:02:45.685
or a very prominent family in Mecca.

00:02:45.685 --> 00:02:48.100
He was born to the Quraysh tribe,

00:02:48.100 --> 00:02:52.396
and the Quraysh tribe was
essentially in control of Mecca,

00:02:52.396 --> 00:02:55.779
and Mecca was a very
powerful city to control

00:02:55.779 --> 00:02:59.780
because it was a religious
center for the region.

00:02:59.780 --> 00:03:02.715
This is the Kaaba, which exists today,

00:03:02.715 --> 00:03:06.292
and is the center of Islamic worship.

00:03:06.292 --> 00:03:09.351
And, at the time, it
housed hundreds of idols

00:03:09.351 --> 00:03:12.537
which were important to the
various tribes and people

00:03:12.537 --> 00:03:14.507
of Arabia at the time.

00:03:14.507 --> 00:03:16.632
And so, you can imagine
as they did the pilgrimage

00:03:16.632 --> 00:03:19.372
towards Mecca to worship their idols,

00:03:19.372 --> 00:03:24.248
it also benefited the economy
of Mecca in a significant way.

00:03:24.248 --> 00:03:26.616
And not only was Muhammad
born into this powerful tribe,

00:03:26.616 --> 00:03:28.857
he was born into one of
the most powerful clans

00:03:28.857 --> 00:03:29.960
within that tribe,

00:03:29.960 --> 00:03:33.849
and within one of the most
powerful houses within that clan.

00:03:33.849 --> 00:03:36.543
But even though he was born
into this very powerful family,

00:03:36.543 --> 00:03:41.280
clan, and tribe, his early
life was quite difficult.

00:03:41.280 --> 00:03:45.123
His father died right before he was born.

00:03:45.123 --> 00:03:48.675
His mother dies at the
age of six years old,

00:03:48.675 --> 00:03:51.050
and, then, his grandfather,

00:03:51.050 --> 00:03:54.294
who then takes custody of him,

00:03:54.294 --> 00:03:58.461
and by most accounts, he
doesn't get a lot of privileges.

00:03:59.424 --> 00:04:00.784
When you're a member of a tribe,

00:04:00.784 --> 00:04:02.665
you're essentially orphaned.

00:04:02.665 --> 00:04:05.880
The tribe is doing, essentially,
just the base necessities

00:04:05.880 --> 00:04:07.380
to keep you alive.

00:04:08.261 --> 00:04:11.117
But then his grandfather dies
when he is eight years old,

00:04:11.117 --> 00:04:13.439
and he becomes, he goes under the custody

00:04:13.439 --> 00:04:15.982
of his uncle, Abu Talib.

00:04:15.982 --> 00:04:20.394
Now, as he grows older,
he does learn a skill.

00:04:20.394 --> 00:04:22.925
He essentially becomes a merchant.

00:04:22.925 --> 00:04:26.524
He goes on trading journeys
with his uncle, Abu Talib,

00:04:26.524 --> 00:04:28.904
to places like Syria.

00:04:28.904 --> 00:04:32.619
And, as he does that,
according to Islamic tradition,

00:04:32.619 --> 00:04:35.440
he gets a very favorable reputation.

00:04:35.440 --> 00:04:39.620
He gets these titles like,
Al-Amin, the trustworthy one,

00:04:39.620 --> 00:04:42.282
or Al-Sadiq, the truthful.

00:04:42.282 --> 00:04:46.354
Now, he continues doing
that until the age of 25.

00:04:46.354 --> 00:04:49.581
At 25 years old, something
very interesting happens.

00:04:49.581 --> 00:04:54.133
A very wealthy widow, arguably
one of the wealthiest people

00:04:54.133 --> 00:04:58.242
in all of Mecca, who runs
a vast trading enterprise,

00:04:58.242 --> 00:05:00.204
Khadija, who is 40 years old,

00:05:00.204 --> 00:05:02.410
she employs Muhammad and, apparently,

00:05:02.410 --> 00:05:04.860
is so impressed by his honesty,

00:05:04.860 --> 00:05:07.610
by his ability to be trustworthy,

00:05:09.454 --> 00:05:11.823
that she propose to him,

00:05:11.823 --> 00:05:13.946
and, remember, she's 40.

00:05:13.946 --> 00:05:16.885
This would be her third
marriage, and he is 25,

00:05:16.885 --> 00:05:19.659
and he accepts the proposal.

00:05:19.659 --> 00:05:22.562
Now, this is significant because
as we'll see in this video

00:05:22.562 --> 00:05:26.486
and the next, Khadija is the
first one to follow Muhammad,

00:05:26.486 --> 00:05:29.586
or believe in Muhammad's revelations.

00:05:29.586 --> 00:05:33.429
So, he continues to work with his wife,

00:05:33.429 --> 00:05:36.215
arguably work for his wife,

00:05:36.215 --> 00:05:40.357
and, then, in 610, he's now 40 years old,

00:05:40.357 --> 00:05:42.274
he is praying in a cave

00:05:43.465 --> 00:05:45.956
on the outskirts of Mecca,

00:05:45.956 --> 00:05:48.243
and while he's praying, he is purported

00:05:48.243 --> 00:05:51.250
to get his first revelation from God,

00:05:51.250 --> 00:05:53.909
according to Islamic traditions.

00:05:53.909 --> 00:05:56.076
And that first revelation,

00:05:57.237 --> 00:06:00.399
and this is the mountain where
it is purported to happen,

00:06:00.399 --> 00:06:02.489
the Mountain of Light, Jabal an-Nour.

00:06:02.489 --> 00:06:04.532
This is the cave, Cave Hira.

00:06:04.532 --> 00:06:07.968
The first revelation is,
"Proclaim, in the name of thy Lord

00:06:07.968 --> 00:06:10.139
"and Cherisher, Who created man,

00:06:10.139 --> 00:06:12.589
"out of a clot of congealed blood.

00:06:12.589 --> 00:06:15.155
"Proclaim, and thy Lord is most bountiful,

00:06:15.155 --> 00:06:16.664
"who taught by the pen,

00:06:16.664 --> 00:06:20.426
"taught man that which he knew not."

00:06:20.426 --> 00:06:23.886
And so Muhammad, according
to Islamic accounts,

00:06:23.886 --> 00:06:26.790
he's kind of very concerned by this.

00:06:26.790 --> 00:06:28.866
He does not view himself as a preacher.

00:06:28.866 --> 00:06:31.363
He does not view himself as someone

00:06:31.363 --> 00:06:34.924
who should be a prophet,
and he goes to Khadija,

00:06:34.924 --> 00:06:37.500
and he's worried, and Khadija takes him

00:06:37.500 --> 00:06:40.186
to her Christian cousin,
who reassures Muhammad,

00:06:40.186 --> 00:06:43.460
who tells Muhammad that he
believes that he is a prophet

00:06:43.460 --> 00:06:46.502
in the tradition of Abraham and Moses.

00:06:46.502 --> 00:06:48.963
And so, that, to some degree,

00:06:48.963 --> 00:06:50.716
makes Muhammad feel a little bit better,

00:06:50.716 --> 00:06:53.294
and he doesn't have some
revelations for awhile,

00:06:53.294 --> 00:06:54.861
and he becomes concerned.

00:06:54.861 --> 00:06:56.370
But then, he eventually starts

00:06:56.370 --> 00:06:58.530
to have many, many revelations,

00:06:58.530 --> 00:07:00.608
but he keeps it to himself, at first.

00:07:00.608 --> 00:07:02.617
But, roughly three years later, he starts

00:07:02.617 --> 00:07:05.275
to publicly preach these revelations.

00:07:05.275 --> 00:07:07.319
So, these revelations which really talk

00:07:07.319 --> 00:07:10.002
about the oneness of God.

00:07:10.002 --> 00:07:11.986
There's no God but God.

00:07:11.986 --> 00:07:15.132
It's very appealing especially to some

00:07:15.132 --> 00:07:17.582
of the economically lower strata,

00:07:17.582 --> 00:07:18.882
but you could also imagine,

00:07:18.882 --> 00:07:23.049
it's very, very threatening
to the establishment of Mecca.

00:07:24.118 --> 00:07:27.195
You have to remember, the
establishment of Mecca,

00:07:27.195 --> 00:07:31.028
it revolves around the
worship of these idols,

00:07:32.025 --> 00:07:34.927
and now you have this
guy of the Quraysh tribe,

00:07:34.927 --> 00:07:37.737
the tribe that worships Hubal,

00:07:37.737 --> 00:07:39.550
the tribe that is in charge of Mecca,

00:07:39.550 --> 00:07:41.638
that benefits from all these people

00:07:41.638 --> 00:07:43.240
worshiping these various idols.

00:07:43.240 --> 00:07:45.864
He's know saying that,
"Idol worship is a sin."

00:07:45.864 --> 00:07:48.151
He's saying that there's not God but God,

00:07:48.151 --> 00:07:51.239
that all of these idols are false idols.

00:07:51.239 --> 00:07:54.258
And so, the Quraysh tribe,
Muhammad's own tribe,

00:07:54.258 --> 00:07:57.985
begins to significantly
persecute the early Muslims.

00:07:57.985 --> 00:08:01.386
So much so, that many of
the early Muslims have

00:08:01.386 --> 00:08:05.682
to migrate from Mecca
to the Kingdom of Axum,

00:08:05.682 --> 00:08:07.075
which was ruled by a Christian king,

00:08:07.075 --> 00:08:10.523
who protects them the Quraysh tribe.

00:08:10.523 --> 00:08:14.656
This is now modern-day
Ethopia, or Eritrea.

00:08:14.656 --> 00:08:18.823
And so, things are not going
well for these early Muslims.

00:08:21.177 --> 00:08:23.116
They're being targeted
by the Quraysh tribe.

00:08:23.116 --> 00:08:24.107
They're being killed.

00:08:24.107 --> 00:08:25.468
They're being tortured.

00:08:25.468 --> 00:08:27.964
And then, things get
even worse for Muhammad.

00:08:27.964 --> 00:08:32.469
In 619, you have the death
of his wife, Khadija.

00:08:32.469 --> 00:08:35.487
And, just to get a sense
of how powerful Khadija was

00:08:35.487 --> 00:08:39.841
to Muhammad, we have
this quote that we get

00:08:39.841 --> 00:08:42.999
from the Hadith, which are
accounts of Muhammad's life

00:08:42.999 --> 00:08:45.332
and sayings, and it tell us,

00:08:46.729 --> 00:08:49.456
"God Almighty never
granted me anyone better

00:08:49.456 --> 00:08:50.905
"in this life than her.

00:08:50.905 --> 00:08:53.320
"She accepted me when people rejected me,

00:08:53.320 --> 00:08:55.816
"she believed in me
when people doubted me,

00:08:55.816 --> 00:08:58.905
"she shared her wealth with
me when people deprived me,

00:08:58.905 --> 00:09:01.946
"and God granted me
children only through her."

00:09:01.946 --> 00:09:06.277
This is, once again,
according to the sayings

00:09:06.277 --> 00:09:08.195
or the life of Muhammad

00:09:08.195 --> 00:09:12.109
as accounted for by one of the Hadith.

00:09:12.109 --> 00:09:13.553
And not only did his wife,

00:09:13.553 --> 00:09:16.018
who up to that time was his only wife,

00:09:16.018 --> 00:09:17.771
die and was a significant figure,

00:09:17.771 --> 00:09:21.904
but in that same year,
his uncle also dies.

00:09:21.904 --> 00:09:24.342
So, you can imagine this year, 619,

00:09:24.342 --> 00:09:26.060
often referred to as the Year of Sorrows,

00:09:26.060 --> 00:09:28.835
it's a fairly low point for Muhammad.

00:09:28.835 --> 00:09:30.147
He's been preaching for about,

00:09:30.147 --> 00:09:31.958
or he's been getting these revelations

00:09:31.958 --> 00:09:34.826
and preaching for around nine years, now,

00:09:34.826 --> 00:09:37.576
and things are not looking good.


Molecular dipoles

WEBVTT
Kind: captions
Language: en

00:00:00.140 --> 00:00:02.607
- [Instructor] In chemistry
we're going to see situations

00:00:02.607 --> 00:00:07.173
where a molecule, an entire
molecule itself might be neutral

00:00:07.173 --> 00:00:10.951
but because of the differences
in electronegativities

00:00:10.951 --> 00:00:13.601
and how the molecules are structured,

00:00:13.601 --> 00:00:17.653
you might have a partially
positive charge on one side

00:00:17.653 --> 00:00:20.747
and a partially negative
charge on another side.

00:00:20.747 --> 00:00:24.723
And the most famous example
of that is a water molecule.

00:00:24.723 --> 00:00:28.024
A water molecule, the
three-molecule water molecules

00:00:28.024 --> 00:00:31.496
depicted here with the
white oxygen molecule

00:00:31.496 --> 00:00:34.388
in the center and the two
hydrogens right over here.

00:00:34.388 --> 00:00:36.498
And this is the shape
of the water molecules.

00:00:36.498 --> 00:00:39.251
Sometimes you'll see it
with this electron pairs

00:00:39.251 --> 00:00:41.918
on the other end from the oxygen

00:00:44.147 --> 00:00:45.879
from those hydrogens.

00:00:45.879 --> 00:00:48.085
But what's interesting
at least in the course

00:00:48.085 --> 00:00:51.502
of this discussion about a water molecule

00:00:52.518 --> 00:00:55.343
is even though the entire
molecule is neutral,

00:00:55.343 --> 00:00:59.510
you have a total of 10 protons
and 10 electrons in total

00:01:00.649 --> 00:01:01.985
even though it's neutral

00:01:01.985 --> 00:01:05.929
because of this shape
and because the oxygen

00:01:05.929 --> 00:01:10.116
is more electronegative,
you can end up with a

00:01:10.116 --> 00:01:12.339
more positive charge on one end

00:01:12.339 --> 00:01:15.502
and a more negative
charge on the other end.

00:01:15.502 --> 00:01:18.127
And just to reinforce this,
we look at the periodic table

00:01:18.127 --> 00:01:20.526
and we know in general as
we get all the top right,

00:01:20.526 --> 00:01:22.686
we get more and more electronegative.

00:01:22.686 --> 00:01:26.353
An oxygen is one of the
most electronegative

00:01:27.249 --> 00:01:30.676
of the elements, it's a good
bit more electronegative

00:01:30.676 --> 00:01:32.693
than hydrogen right over here.

00:01:32.693 --> 00:01:36.241
So in this situation,
in this water molecule

00:01:36.241 --> 00:01:38.404
the electrons and the covalent bond

00:01:38.404 --> 00:01:41.039
between the hydrogen and the oxygen

00:01:41.039 --> 00:01:44.451
are actually gonna spend more time

00:01:44.451 --> 00:01:46.021
around the oxygen.

00:01:46.021 --> 00:01:48.518
I could draw it something like this.

00:01:48.518 --> 00:01:49.782
They're gonna spend more time around here

00:01:49.782 --> 00:01:52.569
because oxygen likes to hug the electrons

00:01:52.569 --> 00:01:54.428
more than the hydrogen does.

00:01:54.428 --> 00:01:57.406
So what it would do is it form a,

00:01:57.406 --> 00:01:59.392
you could say partial negative charge

00:01:59.392 --> 00:02:02.277
at the side of the molecule
away from the hydrogens

00:02:02.277 --> 00:02:05.892
and a partial positive charge on the sides

00:02:05.892 --> 00:02:07.786
where the hydrogens are.

00:02:07.786 --> 00:02:11.517
In this situation where
you have a separation

00:02:11.517 --> 00:02:15.608
of positive and negative
charges within a molecule,

00:02:15.608 --> 00:02:18.615
this is called a molecular dipole.

00:02:18.615 --> 00:02:20.532
Let me write that down.

00:02:22.804 --> 00:02:24.221
Molecular dipole.

00:02:25.340 --> 00:02:29.517
And in a Physics class you
might study the general idea

00:02:29.517 --> 00:02:33.289
of a dipole and this is an electric dipole

00:02:33.289 --> 00:02:34.649
where you have a separation

00:02:34.649 --> 00:02:37.797
of your positive and negative charges.

00:02:37.797 --> 00:02:40.177
In this case we show the molecular dipole

00:02:40.177 --> 00:02:42.480
because it's a course
across the short space

00:02:42.480 --> 00:02:44.392
of an actual molecule.

00:02:44.392 --> 00:02:47.061
This should not be confused
with a magnetic dipole

00:02:47.061 --> 00:02:49.903
which we might also talk
about in other videos.

00:02:49.903 --> 00:02:54.220
Now in a water molecule the
dipole is a permanent dipole.

00:02:54.220 --> 00:02:56.950
Because we're not changing
electronegativities here,

00:02:56.950 --> 00:03:00.014
the oxygen just likes to
hug those electrons more.

00:03:00.014 --> 00:03:02.178
So this situation, let me write this,

00:03:02.178 --> 00:03:04.428
this is a permanent dipole.

00:03:06.622 --> 00:03:09.977
Because of this permanent
dipole mixes water molecules

00:03:09.977 --> 00:03:12.386
that's what allows these water molecules

00:03:12.386 --> 00:03:14.549
to be attracted to each other.

00:03:14.549 --> 00:03:16.650
So this molecule right over here,

00:03:16.650 --> 00:03:18.662
this end is going to
be partially negative,

00:03:18.662 --> 00:03:22.373
this part and it's gonna
be partially positive.

00:03:22.373 --> 00:03:24.173
This lower case delta here

00:03:24.173 --> 00:03:27.625
is how we denote that partial charge.

00:03:27.625 --> 00:03:28.610
Those look like eight

00:03:28.610 --> 00:03:30.431
so let me write them a little bit neater.

00:03:30.431 --> 00:03:34.614
So partially negative
and partially positive.

00:03:34.614 --> 00:03:38.253
Right over here this would
be partially positive,

00:03:38.253 --> 00:03:41.503
partially positive, partially negative.

00:03:42.367 --> 00:03:45.385
Because of this permanent
dipole of the water molecules,

00:03:45.385 --> 00:03:48.449
you can have attraction, the
partially negative chart sides

00:03:48.449 --> 00:03:51.780
are gonna be attracted to the
partially positive charges.

00:03:51.780 --> 00:03:56.155
These are the famous
hydrogen bonds of water.

00:03:56.155 --> 00:03:57.655
So that is of H2O,

00:04:00.090 --> 00:04:01.859
so that's going to be,

00:04:01.859 --> 00:04:05.263
either most of the attraction
that you see over there.

00:04:05.263 --> 00:04:09.330
Now all molecular dipoles
don't have to be permanent.

00:04:09.330 --> 00:04:13.119
So here is a depiction of
some methane molecules.

00:04:13.119 --> 00:04:14.369
Methane is CH4.

00:04:18.622 --> 00:04:21.451
You see in methane that
the carbon is bonded

00:04:21.451 --> 00:04:24.432
somewhat symmetrically, you
have this tetrahedral shape

00:04:24.432 --> 00:04:28.151
where the hydrogens
are evenly distributed,

00:04:28.151 --> 00:04:30.650
they're getting as far away
as they can from each other

00:04:30.650 --> 00:04:32.945
so there's not, it's a very symmetrical

00:04:32.945 --> 00:04:34.755
and three-dimensions shape.

00:04:34.755 --> 00:04:37.527
Also carbon and hydrogen's
electronegativities

00:04:37.527 --> 00:04:38.777
aren't that far apart.

00:04:38.777 --> 00:04:41.007
Carbon is a little bit
more electronegative.

00:04:41.007 --> 00:04:44.368
But because they are close
and there's this symmetry

00:04:44.368 --> 00:04:49.153
to the actual molecule, there
isn't a permanent dipole

00:04:49.153 --> 00:04:51.250
in this situation.

00:04:51.250 --> 00:04:54.527
However, you have to
remember these electrons

00:04:54.527 --> 00:04:58.032
that are buzzing around
between these bonds

00:04:58.032 --> 00:05:00.907
and around the nuclei
of the different atoms,

00:05:00.907 --> 00:05:03.764
they aren't just staying in one place.

00:05:03.764 --> 00:05:06.431
At any given time you might have

00:05:07.732 --> 00:05:10.982
some of the electrons more on this side

00:05:13.882 --> 00:05:15.299
of this molecule.

00:05:18.071 --> 00:05:21.499
So you'll have a temporary
partial negative charge there,

00:05:21.499 --> 00:05:24.746
maybe a temporary partially
positive charge there.

00:05:24.746 --> 00:05:28.913
And that might be the exact
same time that this molecule

00:05:30.022 --> 00:05:34.360
right over here has, this
molecule right over here

00:05:34.360 --> 00:05:37.351
maybe its electrons happened
to be more distributed more

00:05:37.351 --> 00:05:41.518
in that direction so it's
partially negative there

00:05:42.743 --> 00:05:45.125
and partially positive here.

00:05:45.125 --> 00:05:49.500
So when you have just
these random dipoles form,

00:05:49.500 --> 00:05:52.310
at just a certain moment in
time, just based on that moment

00:05:52.310 --> 00:05:54.265
how the electrons are distributed,

00:05:54.265 --> 00:05:56.503
we call that a temporary dipole.

00:05:56.503 --> 00:05:57.920
Temporary dipole.

00:05:59.237 --> 00:06:00.787
And those temporary dipoles

00:06:00.787 --> 00:06:04.267
can create this temporary
forces between molecules.

00:06:04.267 --> 00:06:05.747
We studied that in other videos,

00:06:05.747 --> 00:06:07.773
the famous London dispersion forces.

00:06:07.773 --> 00:06:10.407
Right at the moment that this
one is partially negative

00:06:10.407 --> 00:06:12.893
and this one is partially positive,

00:06:12.893 --> 00:06:15.107
maybe that's right at the
moment that this one is

00:06:15.107 --> 00:06:17.107
partially negative at this side

00:06:17.107 --> 00:06:19.148
and partially positive at this side.

00:06:19.148 --> 00:06:21.236
So the electrons are spending
a little bit more time here

00:06:21.236 --> 00:06:23.790
and so they might be
attracted to each other.

00:06:23.790 --> 00:06:26.776
Not only could it just
be a temporary thing,

00:06:26.776 --> 00:06:28.253
it could also be induced.

00:06:28.253 --> 00:06:30.653
If this one just happens
to be in that state

00:06:30.653 --> 00:06:32.635
and is partially positive on this side,

00:06:32.635 --> 00:06:34.655
well, the electrons here on this molecule

00:06:34.655 --> 00:06:35.780
will be naturally attracted

00:06:35.780 --> 00:06:37.894
so it might be an induced dipole.

00:06:37.894 --> 00:06:40.657
And you could have, to be more explicit

00:06:40.657 --> 00:06:43.286
induced dipoles because
of an external force

00:06:43.286 --> 00:06:46.543
of the environment like an electric field,

00:06:46.543 --> 00:06:48.184
you could have an induced dipole.

00:06:48.184 --> 00:06:52.253
Let's say you have a molecule
of H2O right over here

00:06:52.253 --> 00:06:56.420
and let's say you have a
molecule of neutral methane

00:06:58.011 --> 00:06:59.259
right over here.

00:06:59.259 --> 00:07:02.377
And that neutral methane, it's
electrons are moving around

00:07:02.377 --> 00:07:05.238
but it has no permanent dipole.

00:07:05.238 --> 00:07:07.859
But as it gets near this water molecule,

00:07:07.859 --> 00:07:10.993
right over here, well it
has a permanent dipole

00:07:10.993 --> 00:07:12.789
where it has a positive charge here

00:07:12.789 --> 00:07:15.706
so maybe the methane molecules electrons

00:07:15.706 --> 00:07:20.159
might be attracted more
to that positive charge.

00:07:20.159 --> 00:07:22.191
So this situation where you take something

00:07:22.191 --> 00:07:26.136
that otherwise would only
maybe have temporary dipoles

00:07:26.136 --> 00:07:28.651
but because it's electrons
might be attracted to something

00:07:28.651 --> 00:07:30.407
or repelled from something.

00:07:30.407 --> 00:07:32.990
Here you could have an induced,

00:07:33.867 --> 00:07:36.617
you could have an induced dipole.

00:07:37.489 --> 00:07:40.274
And dipoles actually don't
just happen to be with

00:07:40.274 --> 00:07:42.244
multi atom molecules.

00:07:42.244 --> 00:07:44.665
You can even have not permanent dipoles

00:07:44.665 --> 00:07:47.140
but you could have induced
or temporary dipoles

00:07:47.140 --> 00:07:48.612
from a single atom.

00:07:48.612 --> 00:07:51.641
Let's say we were to
take an atom of argon.

00:07:51.641 --> 00:07:55.257
The noble gases are famously non reactive.

00:07:55.257 --> 00:07:59.250
So let's say that this
is one atom of argon.

00:07:59.250 --> 00:08:01.908
Let's say that's its electron cloud.

00:08:01.908 --> 00:08:04.152
Let's say that's its nucleus there

00:08:04.152 --> 00:08:07.007
and this is a huge over simplification.

00:08:07.007 --> 00:08:09.479
You could imagine at
just some random point

00:08:09.479 --> 00:08:12.387
the electrons are just a
little bit more distributed

00:08:12.387 --> 00:08:13.823
on that side.

00:08:13.823 --> 00:08:17.858
So you have this temporary
dipole that would form

00:08:17.858 --> 00:08:19.738
where you're more negative here

00:08:19.738 --> 00:08:22.956
and more positive right over here.

00:08:22.956 --> 00:08:25.105
Of course if this is next to something

00:08:25.105 --> 00:08:27.354
they might be able to
interact with each other.

00:08:27.354 --> 00:08:29.878
If this is, maybe you
can even induce this.

00:08:29.878 --> 00:08:31.572
It might not be random,
it might be induced

00:08:31.572 --> 00:08:33.511
by a polar molecule nearby,

00:08:33.511 --> 00:08:35.651
something with a permanent dipole.

00:08:35.651 --> 00:08:38.859
Or it might be induced
by a magnetic field.

00:08:38.859 --> 00:08:42.250
I'll leave you there but this
idea of molecular dipoles

00:08:42.250 --> 00:08:44.370
whether they're permanent,
induced or temporary,

00:08:44.370 --> 00:08:47.409
it's a really neat idea
because it actually explains

00:08:47.409 --> 00:08:50.381
a lot of the properties of molecules,

00:08:50.381 --> 00:08:52.694
their boiling points,
their freezing points,

00:08:52.694 --> 00:08:55.874
how hard it is to get them
to again to a gaseous state

00:08:55.874 --> 00:08:57.631
versus a liquid versus a solid state.

00:08:57.631 --> 00:08:59.860
And we'll see a lot of that in Chemistry.


Multi-step unit conversion examples

WEBVTT
Kind: captions
Language: en

00:00:00.355 --> 00:00:03.516
- [Instructor] Brooklyn
purchased three pounds of pasta

00:00:03.516 --> 00:00:07.886
and 12 ounces of cheese to
make macaroni and cheese.

00:00:07.886 --> 00:00:11.377
What is the total weight, in ounces,

00:00:11.377 --> 00:00:13.497
total weight in ounces,

00:00:13.497 --> 00:00:16.785
of the pasta and cheese combined?

00:00:16.785 --> 00:00:20.210
So they give us the weight
of the pasta in pounds,

00:00:20.210 --> 00:00:24.030
and they give us the weight
of the cheese in ounces,

00:00:24.030 --> 00:00:25.783
and we want to add the total weight,

00:00:25.783 --> 00:00:28.081
but they have to all be in ounces.

00:00:28.081 --> 00:00:28.914
So let's first,

00:00:28.914 --> 00:00:32.233
let's first convert these
three pounds of pasta

00:00:32.233 --> 00:00:35.623
into a certain amount of
ounces of ounce, of pasta.

00:00:35.623 --> 00:00:38.523
So we already know that one
pound is equal to 16 ounces.

00:00:38.523 --> 00:00:39.651
They tell us that.

00:00:39.651 --> 00:00:41.567
So what would three pounds be?

00:00:41.567 --> 00:00:44.401
So, if I had

00:00:44.401 --> 00:00:46.121
three pounds,

00:00:46.121 --> 00:00:48.184
how many ounces would that be?

00:00:48.184 --> 00:00:50.746
I encourage you to pause the
video and think about it.

00:00:50.746 --> 00:00:54.256
Well, let's see, if you're
having three times the pounds,

00:00:54.256 --> 00:00:58.150
you're also going to have
three times the ounces.

00:00:58.150 --> 00:01:01.170
So, if one pound is 16 ounces,
if you have three times

00:01:01.170 --> 00:01:02.708
as many pounds, you're
gonna have three times

00:01:02.708 --> 00:01:04.162
as many ounces.

00:01:04.162 --> 00:01:07.537
So 16 times three is 48,

00:01:07.537 --> 00:01:09.869
48 ounces.

00:01:09.869 --> 00:01:13.434
So Brooklyn, the three pounds
of pasta that she purchased,

00:01:13.434 --> 00:01:17.244
that can also be viewed as 48 ounces.

00:01:17.244 --> 00:01:20.692
48 ounces of pasta.

00:01:20.692 --> 00:01:22.471
So she has 48 ounces of pasta,

00:01:22.471 --> 00:01:24.293
and 12 ounces of cheese.

00:01:24.293 --> 00:01:27.382
So what is the total weight,
in ounces, of them combined?

00:01:27.382 --> 00:01:29.251
Well it's going to be 48

00:01:29.251 --> 00:01:30.084
ounces

00:01:30.973 --> 00:01:32.502
48 ounces

00:01:32.502 --> 00:01:34.574
plus the 12 ounces of cheese.

00:01:34.574 --> 00:01:38.556
48 ounces of pasta plus
12 ounces of cheese,

00:01:38.556 --> 00:01:43.180
give us a total of 60
ounces of pasta and cheese,

00:01:43.180 --> 00:01:44.806
combined.

00:01:44.806 --> 00:01:45.856
Let's do another example,

00:01:45.856 --> 00:01:47.273
with other units.

00:01:48.488 --> 00:01:50.299
So we are told,

00:01:50.299 --> 00:01:53.344
David is making a wall out of bricks.

00:01:53.344 --> 00:01:57.666
Each brick is 2/3 of a foot long.

00:01:57.666 --> 00:01:59.688
Each brick is 2/3 of a foot long.

00:01:59.688 --> 00:02:04.075
There are 20 bricks lined up
end to end to make the wall.

00:02:04.075 --> 00:02:07.752
What is the total length
of the wall in inches?

00:02:07.752 --> 00:02:09.918
We've got to pay attention to the units.

00:02:09.918 --> 00:02:13.094
So they give us the length
of each brick in feet.

00:02:13.094 --> 00:02:15.367
So, we know

00:02:15.367 --> 00:02:16.938
that each brick here,

00:02:16.938 --> 00:02:18.253
let me draw a brick.

00:02:18.253 --> 00:02:22.141
The length here is 2/3 of a foot.

00:02:22.141 --> 00:02:24.167
2/3 of a foot.

00:02:24.167 --> 00:02:26.735
So what would this length be in inches?

00:02:26.735 --> 00:02:29.289
Well, once again, we can look
at the conversion between

00:02:29.289 --> 00:02:30.581
foot and inches.

00:02:30.581 --> 00:02:35.148
If I go from one foot to 2/3 of a foot,

00:02:35.148 --> 00:02:38.115
well I've multiplied by 2/3.

00:02:38.115 --> 00:02:40.794
So, if one foot is 12 inches,
and if I want to know how many

00:02:40.794 --> 00:02:43.577
inches 2/3 inches,

00:02:43.577 --> 00:02:45.944
or 2/3 of a foot is in inches,

00:02:45.944 --> 00:02:48.654
well, I would multiply by 2/3 again.

00:02:48.654 --> 00:02:50.910
In either case, you could
view this as multiplying both

00:02:50.910 --> 00:02:55.263
sides of this conversion, by 2/3.

00:02:55.263 --> 00:02:59.430
And so, 2/3 of a foot
is 2/3 times 12 inches.

00:03:00.279 --> 00:03:04.557
And so 12 times two over three,

00:03:04.557 --> 00:03:07.276
that would be 24 over three.

00:03:07.276 --> 00:03:11.557
So this is going to be
equal to 24 over three

00:03:11.557 --> 00:03:12.839
inches.

00:03:12.839 --> 00:03:16.385
I'll just write I-N for
short, right over here.

00:03:16.385 --> 00:03:20.641
24 over three, which is
equal to eight inches.

00:03:20.641 --> 00:03:24.093
So each brick is, either you
could view it as 2/3 of a foot

00:03:24.093 --> 00:03:27.482
long or you could view it as eight inches.

00:03:27.482 --> 00:03:29.101
Eight inches long.

00:03:29.101 --> 00:03:30.813
And there are 20 bricks lined

00:03:30.813 --> 00:03:32.664
up end to end to make the wall.

00:03:32.664 --> 00:03:35.142
So what is the total length
of the wall in inches?

00:03:35.142 --> 00:03:36.417
Well, it's going to be eight brick,

00:03:36.417 --> 00:03:39.139
each brick is eight inches, times 20.

00:03:39.139 --> 00:03:40.647
Times 20.

00:03:40.647 --> 00:03:42.588
And eight times two is 16,

00:03:42.588 --> 00:03:47.374
so eight times 20 is 160

00:03:47.374 --> 00:03:48.673
inches.

00:03:48.673 --> 00:03:50.202
Let's do one more of these.

00:03:50.202 --> 00:03:53.887
And this time, let's
deal with some volume.

00:03:53.887 --> 00:03:58.054
So this says, Blanca buys
two gallons of green paint.

00:03:59.311 --> 00:04:03.547
She uses five quarts to
paint her front porch

00:04:03.547 --> 00:04:06.164
and 0.5 quarts

00:04:06.164 --> 00:04:09.027
to paint the front porch swing.

00:04:09.027 --> 00:04:12.279
How may quarts of paint
does Blanca have left?

00:04:12.279 --> 00:04:14.801
So we're given the
original amount in gallons,

00:04:14.801 --> 00:04:17.204
but we want to know how
many quarts she has left.

00:04:17.204 --> 00:04:20.441
So let's convert the amount
she originally has into quarts.

00:04:20.441 --> 00:04:23.364
So they tell us one gallon
is equal to four quarts.

00:04:23.364 --> 00:04:24.614
So two gallons,

00:04:25.779 --> 00:04:27.183
two gallons

00:04:27.183 --> 00:04:29.529
is going to be equal to

00:04:29.529 --> 00:04:32.522
two gallons

00:04:32.522 --> 00:04:34.782
is going to be twice as many quarts,

00:04:34.782 --> 00:04:36.865
is gonna be eight quarts.

00:04:38.199 --> 00:04:39.104
So that's what she starts with.

00:04:39.104 --> 00:04:40.107
And one way to think about this,

00:04:40.107 --> 00:04:41.257
I just took this conversion,

00:04:41.257 --> 00:04:43.801
well if I'm a have twice as many gallons,

00:04:43.801 --> 00:04:46.212
then I'm gonna have twice as many quarts,

00:04:46.212 --> 00:04:48.681
if I want to express
that volume in quarts.

00:04:48.681 --> 00:04:49.893
So, one way of thinking about it,

00:04:49.893 --> 00:04:51.754
she starts with eight quarts.

00:04:51.754 --> 00:04:54.171
She starts with eight quarts.

00:04:55.339 --> 00:04:56.825
Eight quarts.

00:04:56.825 --> 00:05:00.603
She uses five quarts to
paint her front porch.

00:05:00.603 --> 00:05:03.494
So minus five quarts,

00:05:03.494 --> 00:05:04.957
on the front porch,

00:05:04.957 --> 00:05:05.963
is what she used.

00:05:05.963 --> 00:05:08.968
And she used .5 quarts
to paint the porch swing.

00:05:08.968 --> 00:05:13.718
So minus 0.5 quarts.

00:05:13.718 --> 00:05:15.892
That looks like a "g."

00:05:15.892 --> 00:05:18.212
0.5 quarts.

00:05:18.212 --> 00:05:19.956
Well, what is that going to be?

00:05:19.956 --> 00:05:22.834
Well, eight minus five is three,

00:05:22.834 --> 00:05:25.764
minus .5 is 2.5.

00:05:25.764 --> 00:05:30.130
So she is going to be
left with 2.5 quarts.

00:05:30.130 --> 00:05:31.674
And we have answered the question

00:05:31.674 --> 00:05:33.506
in terms of the units they care about.

00:05:33.506 --> 00:05:35.173
In terms of quarts.


Metric system unit conversion examples

WEBVTT
Kind: captions
Language: en

00:00:00.596 --> 00:00:03.786
- [Instructor] Tomas dropped
off two packages to be shipped.

00:00:03.786 --> 00:00:06.703
One package weighed 1.38 kilograms,

00:00:08.953 --> 00:00:12.286
and the other package weighed 720 grams.

00:00:13.293 --> 00:00:15.253
So the first one they give in kilograms,

00:00:15.253 --> 00:00:18.213
and the second one they give us in grams.

00:00:18.213 --> 00:00:23.213
What was the combined weight
of both packages in grams?

00:00:23.213 --> 00:00:25.642
So what I wanna do is, I'm
gonna convert both of these

00:00:25.642 --> 00:00:29.493
to grams, and then add 'em up
to get the combined weight.

00:00:29.493 --> 00:00:33.616
Well, we already know the
second one is 720 grams,

00:00:33.616 --> 00:00:36.430
but what's the first
one in terms of grams?

00:00:36.430 --> 00:00:38.263
Well, let's see, 1.38,

00:00:39.875 --> 00:00:42.522
I could write kilograms like that.

00:00:42.522 --> 00:00:46.075
Well, if one kilogram is 1,000 grams,

00:00:46.075 --> 00:00:49.148
and that's what the prefix
kilo means, it means 1,000,

00:00:49.148 --> 00:00:51.769
well, to go from one to
1.38, I'm multiplying

00:00:51.769 --> 00:00:52.602
by 1.38,

00:00:54.566 --> 00:00:57.594
so I'm also, if I want
it in terms of grams,

00:00:57.594 --> 00:01:01.177
I'll take 1,000 grams
and multiply by 1.38.

00:01:02.039 --> 00:01:05.214
So this is going to be 1,000 times 1.38

00:01:05.214 --> 00:01:06.464
is 1,380 grams,

00:01:10.367 --> 00:01:13.005
which I could've just denoted with a G,

00:01:13.005 --> 00:01:14.658
but now let's add those together.

00:01:14.658 --> 00:01:16.620
This is the first package,
and then the second package

00:01:16.620 --> 00:01:17.703
is 720 grams,

00:01:20.779 --> 00:01:22.779
and so if I were to add,

00:01:24.434 --> 00:01:28.288
this is going to be,
let's see, got a zero,

00:01:28.288 --> 00:01:29.770
10,

00:01:29.770 --> 00:01:32.759
well let's see, four plus seven is 11,

00:01:32.759 --> 00:01:34.984
and then one plus one is two.

00:01:34.984 --> 00:01:37.317
We get 2,100 grams in total.

00:01:39.762 --> 00:01:43.929
Let's do another one of these
unit conversion examples.

00:01:45.217 --> 00:01:48.424
Julia and her friends are
making kites out of paper.

00:01:48.424 --> 00:01:51.138
For each kite, they need a piece of paper

00:01:51.138 --> 00:01:53.221
that is 0.65 meters wide.

00:01:56.040 --> 00:01:59.778
How many centimeters, how
many centimeters of paper

00:01:59.778 --> 00:02:02.863
will they need to make four kites?

00:02:02.863 --> 00:02:05.706
So they tell us how wide the paper

00:02:05.706 --> 00:02:08.618
is in meters for each kite,

00:02:08.618 --> 00:02:10.610
but they want the answer in centimeters,

00:02:10.610 --> 00:02:12.534
and they want it for four kites.

00:02:12.534 --> 00:02:14.617
So, let's think about this a little bit.

00:02:14.617 --> 00:02:16.700
Each kite is 0.65 meters,

00:02:18.154 --> 00:02:19.154
0.65 meters.

00:02:21.182 --> 00:02:23.603
So to go from one to 0.65,

00:02:23.603 --> 00:02:25.436
you'd multiply by 0.65

00:02:27.708 --> 00:02:28.991
on the meters,

00:02:28.991 --> 00:02:30.750
and so to go to 100 centimeters

00:02:30.750 --> 00:02:32.409
to the number of
centimeters you would need

00:02:32.409 --> 00:02:34.979
for the width of a kite, you'd similarly

00:02:34.979 --> 00:02:36.396
multiply by 0.65.

00:02:38.493 --> 00:02:40.910
Well, 65 hundredths times 100

00:02:41.890 --> 00:02:43.390
is going to be 65,

00:02:45.014 --> 00:02:47.014
65 centimeters per kite.

00:02:48.110 --> 00:02:50.928
So this 0.65 meters wide per kite,

00:02:50.928 --> 00:02:53.928
in centimeters it is 65 centimeters.

00:02:55.472 --> 00:02:57.170
Now, they don't want just how much paper

00:02:57.170 --> 00:02:58.419
will they need to make one kite,

00:02:58.419 --> 00:03:00.790
they want four kites.

00:03:00.790 --> 00:03:03.491
So we would multiply this times four.

00:03:03.491 --> 00:03:04.940
This is how much we need per kite,

00:03:04.940 --> 00:03:06.684
so let's multiply that times four.

00:03:06.684 --> 00:03:10.320
And so let's see, four times five is 20.

00:03:10.320 --> 00:03:12.694
Four times six is 24,

00:03:12.694 --> 00:03:13.944
plus two is 26.

00:03:15.549 --> 00:03:17.549
260 centimeters of paper

00:03:18.434 --> 00:03:21.389
for the width of the four kites.

00:03:21.389 --> 00:03:23.330
Let's do one more of these.

00:03:23.330 --> 00:03:26.113
This is a volume conversion.

00:03:26.113 --> 00:03:29.925
Omar is pouring five liters of water

00:03:29.925 --> 00:03:31.768
into two goldfish bowls.

00:03:31.768 --> 00:03:35.281
He spills 200 milliliters of water,

00:03:35.281 --> 00:03:38.093
and then divides the
remaining water evenly

00:03:38.093 --> 00:03:39.839
between the two bowls.

00:03:39.839 --> 00:03:42.256
How many milliliters of water

00:03:43.314 --> 00:03:45.514
does Omar pour into each bowl?

00:03:45.514 --> 00:03:47.976
So we want our answer at
the end in milliliters,

00:03:47.976 --> 00:03:49.567
and so let's just convert the amount

00:03:49.567 --> 00:03:51.694
that he starts with into milliliters.

00:03:51.694 --> 00:03:54.204
So he starts with five,

00:03:54.204 --> 00:03:56.454
he starts with five liters.

00:03:58.460 --> 00:04:00.789
So how many milliliters
is that going to be?

00:04:00.789 --> 00:04:03.787
Well, they tell us one
liter is 1,000 milliliters,

00:04:03.787 --> 00:04:05.122
so if we have five liters,

00:04:05.122 --> 00:04:07.147
we're multiplying our quantity times five,

00:04:07.147 --> 00:04:10.936
that's gonna be five
times, it's going to be

00:04:10.936 --> 00:04:14.306
five times as many milliliters,

00:04:14.306 --> 00:04:18.306
so that's 1,000 times
five is 5,000 milliliters,

00:04:21.979 --> 00:04:23.752
so that's what he starts with.

00:04:23.752 --> 00:04:26.282
Now, before he splits
this 5,000 milliliters

00:04:26.282 --> 00:04:28.282
between these two bowls,

00:04:29.526 --> 00:04:31.402
he spills 200 milliliters,

00:04:31.402 --> 00:04:33.394
so let's subtract out what he spills,

00:04:33.394 --> 00:04:36.874
'cause he, that's not going
to be able to be split.

00:04:36.874 --> 00:04:37.874
Milliliters.

00:04:38.961 --> 00:04:41.507
And so, that's going to give us,

00:04:41.507 --> 00:04:44.889
so we're gonna have 4,800 milliliters

00:04:44.889 --> 00:04:47.639
to split between those two bowls,

00:04:48.694 --> 00:04:51.004
and so each bowl, that's what they ask us,

00:04:51.004 --> 00:04:53.566
how many milliliters of water
does he pour into each bowl?

00:04:53.566 --> 00:04:55.362
Well, see, if he's gonna
split this into two bowls,

00:04:55.362 --> 00:04:57.359
each bowl's gonna get half of this,

00:04:57.359 --> 00:05:01.567
and so each bowl is going
to get half of 4,800,

00:05:01.567 --> 00:05:03.213
so we just divide that by two,

00:05:03.213 --> 00:05:07.130
so each bowl is going to
get 2,400 milliliters,

00:05:08.467 --> 00:05:11.800
2,400 milliliters and 2,400 milliliters.

00:05:14.805 --> 00:05:17.555
That's how much each bowl is going,

00:05:17.555 --> 00:05:21.722
that's how much Omar is
going to pour into each bowl.