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Sound

Sound
Sound
               Sound is form of energy.
Production of Sound
               Sound is produced by all types of vibrating objects.
Nature of sound propagating
                         Sound is a example of mechanical wave. Which need medium for their propagation. The sound energy vibrates the participles of the medium parallel to the way of propagation.

The sound waves propagate through medium due to difference of pressure at different regions of the medium. The portion of the medium where the pressure is high called compression. And the region where pressure is low called rarefaction.
So the sound waves propagate in the form of compression and rarefaction. Sound wave is also called longitudinal waves.
Characteristics of sound
         Basically the sound possessed the following main characteristics.
    loudness of sound
    Intensity of sound
    Pitch of sound
    Quality of sound
Loudness of sound
             The differentiation between the faint and loud sound is called loudness of sound.
Loudness of sound depends upon the five main factors.
  1)       The amplitude of vibrating objects.
  2)       The direction of medium.
  3)       The distance between the observer and transmitter
  4)       The area of vibrating objects.
  5)       The temperature of the medium and condition of observer.
Intensity of sound
Definition
         The number of sound wave passes through cross sectional area (A). The cross sectional area held perpendicular to the way of propagation of the sound waves. The Intensity of sound is independent of the loudness of sound. Intensity of sound is denoted by (I).
Derivation
                The sound energy (E) passing through any cross sectional area (A) in given time (t). The cross sectional area (A) must be perpendicular to the way of propagation.
 Intensity of sound=Sound Energy/Area*time
 I=E/A*t
 Energy=Work
  E=W
 I=W/A*t
 I=W/t*1/A
As power=Work/time
 I=P*1/A
 I=P/A
Weber Fechnar Rule or Law
                          Weber Fisher law makes relation between the intensity (I) of the sound and its loudness (L). This stated As That
 The loudness (L) of the sound is directly proportional to the (Log ) of the Intensity (I).
 Mimetically
 Loudness Log (Intensity)
 L Log I
 L=constant Log I
 L=K log I
       Where If intensities varies by amount of 10, 100, 1000, 10000 ... Then loudness varies by amount of 1, 2, 3, 4. .... And (K) is the constant of proportionality which shows that the ratio between (L) and (I) are always constant.
Threshold of hearing
Threshold of hearing=Faintest audible sound
 I=10 -12Wm 2= 0 Decibel (db)
So we use Decibel denoted by (db) is the unit used to measure intensity of sound.
Intensity level or sound level
                The difference between the loudness of two sounds is known as the Intensity of sound level. It is denoted by Delta L
Pitch
          The differentiation between the grave (loud) and shrill sound is know as Pitch of the sound. Pitch of the sound depends upon the frequency.
  High frequency sounds have high Pitch.
  Low frequency sounds have low Pitch.
Example
            Women have higher Pitch. Where as men have low Pitch. The high Pitch sound moves fast ad travel high distance as compare to low Pitch.
Quality of sound
                            The differentiation between two same identical waves (same wave length, same amplitude, and same frequency) but the sounds are produced by two different instrument. This is due to the difference of the shape of the sound waves which is produced by two instruments.
Music and Noise
  Music
           The sounds which produce pleasant effect on the sense of hearing is known as music. OR The sound which changes gradually its frequency, wave length and amplitude is called music.
 Noise
            The sound which produced unpleasant effect on the sense of hearing is known as noise. OR The sound in changes suddenly is called noise.
Speed of sound
                      It is a devise which is used to find out the approximate value of speed of sound.
Resonance force
                     When two identical waves interact with each other and there frequencies match with each other, they reinforce each other and the resultant frequency is the sum of two waves which is known as resonance force.
Audible frequency Range
                         We know that sound is produced by a vibrating body. A simple pendulum also vibrates but it does not produce any sound. The reason is that its vibrations are very slow. A human ear can hear a sound only if its frequency lies between 20Hz and till 20,000Hz. Sounds of frequency beyond 20,000Hz are inaudible because the eardrum can not vibrate so rapidly. The audible frequency range differs a little for different persons. And it also decreases with age, Young children can hear sounds of 20,000Hz frequency, but old people can not hear sounds even above 15,000Hz frequency.
Ultrasonics
                  We know that human ear can not hear sounds of frequency less than 20Hz or more than 20,000Hz. Sounds of frequency higher than 20,000Hz, which are inaudible to human ear, can be produced and utilized many useful ways. Such sounds are called ultrasonics.

Wave and Motion

Wave
          A mechanism by which energy can transfer from one region to another region through medium without the actual movement of the medium itself.
Basically waves are classified into two main groups.
       1) Mechanical wave
       2) Electromagnetic wave
Mechanical wave
  Such wave which need medium for their propagation. Like sound wave, water wave, string wave.
  Mechanical waves are divided into two types.
       1) Transverse wave
       2) Longitudinal wave or Compressional wave
Transverse wave
Such mechanical wave whose particles are perpendicular to the way of propagation. Like water wave or string wave.
Longitudinal wave or Compressional wave
                                 Such type of mechanical wave in which the particles of the medium is parallel towards the propagation. Like sound wave. It moves due to compression and rare faction. At the region of compression pressure is high where as the region of rare faction the pressure is low. So due to this P.D the wave moves.
Electromagnetic wave
            Such wave which don't need medium for their propagation, like light wave and radio wave.
Electromagnetic waves are transverse waves.
Characteristics of wave
      There are some characteristics associated with the wave motion.
           1)   Wave length
           2)   Amplitude
           3)   Time period
           4)   Frequency
           5)   Velocity
Wave length
  The distance between two consecutive crest or trough is known as wave length. It is denoted by (l). The unit used to measure wave length is meter (m).
Crest
  The portion of the wave above the equilibrium position is called crest.
Trough
  The portion of the wave below the equilibrium position is called trough.
Vibration
  A complete round trip of wave is called one vibration or one cycle.
Amplitude
  The peak value of wave on either side of the equilibrium position, or the maximum height of the wave from equilibrium position is called amplitude.
Time Period
  Time of one vibration or time interval needed for a wave to complete one vibration or one cycle. Time Period is denoted by (T) and its unit is second (s).
Frequency
  The number of vibration passing a point in unit time is called frequency. It is denoted by (f) the unit used to measured the frequency is hertz (Hz), cycle/second (c/s) or Vibration/second=vib/sec or the reciprocal of time period
Hook's Law
  Hook's Law is applied on elastic object like spring or rubber..... This is stated as, if the spring (elastic object) are stretched or compressed by external force (Fext). Due to external force object displaced or produce displacement (x) in the spring. So the external force has done work.
So the work is done and store is the spring in the form of elastic restoring force (Fr) and the elastic restoring pull back the spring to its original position. The magnitude of restoring force is directly proportional to the displacement and opposite in direction to that displacement.
Mathematically:
  Fr a -y
  Fr=constant (-x)
  Fr=k(-x)
  Fr=-kx
Simple Harmonic Motion (S.H.M)
  It is a type of vibrating motion in which the acceleration produced due to elastic restoring force (Fr) and it is directly proportional to the negative of the displacement (X) which is produced due to external force (Fext) and always directed towards the mean position
Conditions for S.H.M
     1)      The system must have restoring force.
     2)      The system must have inertia (m).
     3)      The plane over which attached to spring moving must be frictionless  
               and at the point of spring and firm support.  
Characteristics or feature of S.H.M
             Any system executing S.H.M have the following main characters or Features.
1)     At extreme position the P.E is maximum. Because displacement (X) is
         Maximum and K.E is zero. Because velocity is zero.
2)     At mean position the K.E is maximum. Because velocity is maximum  
         while the P.E is zero. Because displacement(X) is zero.
3)     The acceleration always directed towards the mean position and it is  
         directed in the direction of restoring force(Fr).  
4)      Displacement and acceleration are always in opposite direction.
Pendulum
Definition
                Simple pendulum is consisting of bob (hard steel sphere), inextensible string and firm support. One end of spring attached with bob and the other end with firm support. These three components are from the system of simple pendulum.
Explanation
              If the bob is displaced through displacement (X) by an external force (Fext) from point (O) to point (B) against the gravitational field. So the work done by external force stored in the pendulum in the form of gravitational potential energy. When the applied external force release and the bob moves towards the mean position, Due to change of G.P.E into K.E the bob do not stay to point (O.) due to inertia (mass) the bob moves to other G.P.E side of the mean position at point (A) and again don't stay there. and moves to point (O) and then to point (B) and the bob repeats its movement about the mean position in the regular interval of time. The acceleration produce and it is always directed towards the mean position and directly proportional to the displacement (X) produce due to external force. Therefore the Simple Pendulum also executes S.H.M like mass attached to spring.
It is experimentally proved the time period of simple pendulum as
  T=2pl/g
Where T=time period of pendulum
L=length of the string of pendulum
g=gravitational acceleration.
Properties of waves
           Basically any types of wave exhibit (to show) four basic properties which are as follows.
            1)    Reflection
            2)    Refraction
            3)    Diffraction
            4)    Interference
Reflection
              When the transmitted waves (water waves, light waves, sound waves-------) strike any plane surface.(In the case of light waves on plane mirror)with the some angle after stricking with the plane it bounce back to the same medium from which it transmitted in this case is known as reflection.
Refraction
                       The banding of waves when it enters from one medium to another medium is known as refraction. The waves bend towards normal when it enters from rare medium into dense medium to the reduction is the speed of the waves.
Diffraction
        The bending of waves around the corners of objects or obstacles is known as Diffraction.
Interference
               When two (or more than two) waves each gives own displacement to the same particle of medium. The resultant displacement is equal to some of all the individual displacement. This phenomenon is known as Interference of waves.
Constructive interference
                    When two identical waves (same amplitude, same wave length, and same frequency) moving along the same direction propagation along the same medium. If both waves are in phase when they interact and they produce Constructive interference pattern (arrangement) and the resulting waves are with individual waves reinforce each other.
Destructive Interference
                          When two identical waves generated in same medium propagating in same direction, If waves are out of phase. When they interact they produce interference pattern. Which is destructive in nature and they cancel the effect of each other and the resultant waves is zero (The medium through which wave generated came into its undisturbed level).

Stationary Waves or Standing Waves
              When two identical waves (same amplitude, same frequency, same wave) generated in the same medium but propagating in opposite direction, If both waves are out of phase when they interact with each other. They formed standing waves or stationary waves. Both waves lock each other and form Loops. The 1st loop is known as the 1st Harmonic or Fundamental harmonic, 2nd is called 2nd harmonic and so on.
Fandamental or 1st Harmonic
The frequency (f) of the standing wave divided by number of loops
    

Isaac Newton

Newton was an English physicist and mathematician, and the greatest scientist of his era.

Isaac Newton was born on 4 January 1643 in Woolsthorpe, Lincolnshire. His father was a prosperous farmer, who died three months before Newton was born. His mother remarried and Newton was left in the care of his grandparents. In 1661, he went to Cambridge University where he became interested in mathematics, optics, physics and astronomy. In October 1665, a plague epidemic forced the university to close and Newton returned to Woolsthorpe. The two years he spent there were an extremely fruitful time during which he began to think about gravity. He also devoted time to optics and mathematics, working out his ideas about 'fluxions' (calculus).

In 1667, Newton returned to Cambridge, where he became a fellow of Trinity College. Two years later he was appointed second Lucasian professor of mathematics. It was Newton's reflecting telescope, made in 1668, that finally brought him to the attention of the scientific community and in 1672 he was made a fellow of the Royal Society. From the mid-1660s, Newton conducted a series of experiments on the composition of light, discovering that white light is composed of the same system of colours that can be seen in a rainbow and establishing the modern study of optics (or the behaviour of light). In 1704, Newton published 'The Opticks' which dealt with light and colour. He also studied and published works on history, theology and alchemy.

In 1687, with the support of his friend the astronomer Edmond Halley, Newton published his single greatest work, the 'Philosophiae Naturalis Principia Mathematica' ('Mathematical Principles of Natural Philosophy'). This showed how a universal force, gravity, applied to all objects in all parts of the universe.

In 1689, Newton was elected member of parliament for Cambridge University (1689 - 1690 and 1701 - 1702). In 1696,Newton was appointed warden of the Royal Mint, settling in London. He took his duties at the Mint very seriously and campaigned against corruption and inefficiency within the organisation. In 1703, he was elected president of the Royal Society, an office he held until his death. He was knighted in 1705.

Newton was a difficult man, prone to depression and often involved in bitter arguments with other scientists, but by the early 1700s he was the dominant figure in British and European science. He died on 31 March 1727 and was buried in Westminster Abbey

The Great Hazara General Musa Khan

Musa Khan was the Chief of Army Staff, Pakistan; he succeeded Field Marshal Ayub Khan, who was then President.He was the oldest son of Sardar Yazdan Khan. He was a Naik (junior officer) in Hazara Pioneers and went to the Indian Miliary Academy in Dehra Dun as a cadet and graduated with the first batch of the Indian commissioned officers. He was posted to the 6th Royal Battalion,the 13th Frontier Force Rifles as a Platoon Commander in 1936. He took part in the Waziristan Operations in 1936-1938 and in World War II, where he served in North Africa. He served with distinction in the Pakistani Army and became the commander-in-chief (C in C) of Pakistan Armed Forces during President Mohammad Ayub Khan’s regime (1958-1969). In the War of 1965, Indian Army attacked West Pakistan from Lahore border, with 600 tanks and 5 time bigger force then Pakistan Army, General Musa Khan defended the country with heart and soul. The Wahaga battle field became the graveyard of Indian tanks.

After he retired from the army, President Ayub Khan appointed him as Governor of West Pakistan (1967-1969) and after serving for a few years, he retired and settled in Karachi. In 1987, he was appointed as Governor of Balochistan Province by President Muhammad Zia-ul-Haq. In Balochistan, Governor (Retd) General Mohammad Musa dissolved the assembly in December 1988. However, the Balochistan High Court restored the assembly amid public condemnation of Governor's move that was believed to be taken with the consent of the President and Prime Minister.


Operation Gibralter

General Mohammed Musa, who commanded the Army in the 65 War, gave his account of how the Indians surprised the GHQ, the C-in-C and the Supreme Commander Field Marshal Ayub Khan on September 6, 1965. Narrates Musa Khan in his book "My Version":
India launched her ignominious, undeclared and blatant aggression on our homeland at about 0330 hours on 6 September. The Supreme Commander was informed about the invasion by Air Commander Akhtar of the Pakistan Air Force, who was on duty at the Air Defence Headquarters at Rawalpindi on night of 5th-6th September. Indian troop movements across the frontier had been reported to him by the border posts of the PAF Wireless Observer wing. The President then rang me up to ascertain whether or not GHQ had received any information about the Indian attack and the whereabouts of the field army that morning.

Lt. General Musa describes the genesis of the surprise Indian attack on 6th September in his own words:
The then Foreign Minister Mr Zulfiqar Ali Bhutto, and the Foreign Secretary, Aziz Ahmed spurred on by Major General Akhtar Hussain Malik, who was commander of our troops in Azad Kashmir, pressed the Government to take advantage of the disturbed situation in the valley and direct the Army to send raiders into Indian held Kashmir for conducting guerrilla activities there and to help, on a long term basis, the locals in organising a movement with a view to eventually starting an uprising against the occupying power.

Continues the former C-in-C in his book, the sponsors and supporters of the raids had at last succeeded in persuading the President to take the plunge that led to an all-out armed conflict with India' .......

The concept of sending infiltrators in the Indian held Kashmir, code named Gibraltar was the brain-child of the ministry of Foreign Affairs but General Musa assumed full responsibility for the development of the concept, its planning and coordination of the entire operation. He says:
After the Government finally decided that deep raids should be launched in Indian-held Kashmir, I directed Commander 12 Division, Major General Akhtar Hussain Malik, to prepare a draft plan for the operation, code-named 'Gibraltar' in consultation with GHQ and within the broad concept we had specified. GHQ approved it after making certain changes in it. With the help of sand model, he went over the final plan in Murree before it was put into effect on 7 August, 1965 under our overall control. The Supreme Commander and his Military Secretary were present. He also agreed with it. I was accompanied by the CGS (Major General Sher Bahadur) and the Directors of Military Operations and Intelligence Brigadiers Gul Hasan and Irshad Ahmed Khan respectively. No civil official attended this briefing.

Broadly the plan envisaged, on a short-term basis, sabotage of military targets, disruptions of communications, etc. and, as a long-term measure, distribution of arms to the people of occupied Kashmir and initiation of a guerrilla movement there with a view to starting an uprising in the valley eventually. The push towards Akhnur was not part of it. However, it was considered as one of the likely operations that we might have to undertake, as we felt our activities would have an escalating effect.

Nevertheless, when the Indians started attacking and capturing Azad Kashmir territory in Tithwal and Haji Pir Pass areas, we decided to hold them in these places and retaliate by threatening Akhnur through the Chamb valley in order to release the pressure in the north.

The simple truth emerging from the preceding statement of General Musa is clear in that, while the concept of 'Gibraltar' did originate from the ministry of Foreign Affairs, General Musa, whatever he might say after the event, went along with it in a half heartedly and non serious manner leading to the downfall of President of Pakistan General Ayub Khan via Tashkent Agreement.

The loser in the final analysis was Pakistan, described so feelingly by General K.M. Arif in an analysis carried by "Daily Dawn", 6th September 1990.

How and why Pakistan blundered into war .......... At that time, the policy making in the country was highly personalised. The institutions were weak and by-passed. Pakistan's Foreign Office with Mr. Aziz Ahmed as the Foreign Secretary and Mr. Z.A. Bhutto as the Foreign Minister called the martial tunes. It had miscalculated that despite operation Gibraltar, the fighting was likely to remain confined inside the disputed state of Jammu and Kashmir. The Foreign Office is on record to have assessed that India was not in a position to risk a general war with Pakistan......for inexplicable reasons the General Headquarters based its operational plan in Kashmir on a wishful logic. The misplaced ego, the high ambition and the naive approach of a selected few , plunged Pakistan into an armed conflict. The outcome of the war, or the lack of it, eclipsed Ayub Khan's position.


At a briefing arranged at SSG Parachute Training School at Peshawar in the presence of two senior officers, Lt. Col. Abdul Matin, the Commander of No. 1 Commando Battalion, now retired and the brilliant Operations Staff Officer Maj. E. H. Dar, (Late Major General E. H. Dar) the Air Force Chief was told that only a pre-emptive operation like the Israeli crippling raids against the front line Arab State's air bases as in 1956 Arab-Israel War, could have probability of success. To this, the Air Chief observed that a decision to carry out pre-emptive operation as suggested could only be taken by the Government (meaning President Ayub Khan). Technically the observation made was correct but in that case the operation should have been based on the hypothesis of pre-emptive alone. There was also objection by the Military Operations Experts to the dropping of Para commandoes in Kashmir with no equivalent of French Maquis to hide, feed and organise their escape and was tantamount to suicide.

General Musa Khan, Field Marshal Ayub Khan's C-in-C, was the archetype of the loyal commander. But after him Ayub appointed another favorite, Yahya Khan. Zulfikar Ali Bhutto set up a ' Liberation Cell ', which included people like:
Mr Aziz Ahmed
Mr Nazir Ahmed
Mr Ayub Buksh Awan
Mr NA Farooqi
Mr Ahmed
Mr Altaf Goher (although the latter did not attend any of the meetings)


General Musa, Commander in Chief of the Pakistan Army at that time, confirms the existence of this 'Cell', which was set up in August of 1964. The majority of the members of this 'Cell' were from the 'Qadiani sect’, he pointed out.

When this ambitious plan was first sent to the GHQ, General Musa opposed it and wrote the following points to the President Ayub Khan:
Guerrilla war in Kashmir can only be successful if the people of Kashmir take part in it, and in my opinion we need more time to prepare people for this.
During the guerrilla war if India realized that it is losing the war in Kashmir, she will attack Pakistan.
As long as Pakistan is not in a position to defeat India militarily, we should not venture such operation in Kashmir.
In order to defeat India we need more army, better arms and better training.

General Musa asked for money to set up two more army divisions to face the challenge. General Ayub in principle agreed with this idea, but the Finance Minister Mr Shoaib persuaded him against this by saying that the Pakistan economy cannot afford it. And this idea was dropped. It is ironic that no such army was raised before the start of the ‘Operation Gibraltar’ or during its operations, but after the war, in the same month, two divisions were set up.

According to Brigadier (R) Farooq, General Musa was a simple man. He gave his opinion about the 'Operation' and then did not make it a matter of pride and remained quiet. if he and General Sher Bahadur who also opposed the idea, had resigned then there would have been no 'Operation Gibraltar'.

A top level meeting was held at the Headquarters of the 12th Division in May 1965. Once again, General Musa opposed the plan, and to this President Ayub Khan said: "Musa I have been assured by the Foreign Office that India would not be involved in a full scale war". When both General Musa and General Sher Bahadur said that if we are to start a guerrilla war at that level, it is very likely that India would react and attack Pakistan. President Ayub Khan reacted by saying: "We will have to take heart sometime".

Apart from the assurance to which President Ayub Khan made reference that India would not attack Pakistan, Pakistani planners of this ‘Operation’ were led to believe that India is not in a position to launch attack against Pakistan until 1966 or 1967. It was emphasized that we do not waste any more time, and start our action as soon as possible.

Musa Says in his book, 'My Version' that the Kashmiris of the Valley were not taken into confidence about the ‘Operation’ that was to be started to liberate them. He wrote:
We had not even consulted the public leaders across the cease fire line about our aims and intentions, let alone associating them with our planning for the clandestine war...

The people of the area to be 'liberated' must have to be taken into confidence, if the people organizing this gigantic task really meant business. Without the help of the local people outside army cannot win a war or even survive. Not only the people of Kashmir living on the other side of the cease fire line were not taken into confidence, also the people of Azad Kashmir, even the Azad Kashmir Government was not taken into confidence. When the ‘Operation’ was put into practice then the planners realized the need to have some Kashmiri support. They already had set up a Liberation Council, and compelled by circumstances they announced that Choudhry Ghullam Abbass was leading this Liberation Council.

Choudhry Ghulam Abbass was already very annoyed with this, he immediately rejected that in a news statement in the Daily Nawa E Waqat the following day:
I have nothing to do with all this, and I did not know anything about an ‘Operation’.

General Musa confirms the above position, he said:
Because of the haste with which the ‘Operation’ was launched, even Azad Kashmir leaders were not taken into confidence by the advocates of Guerrilla raids. Helplessly they remained in the background. Their co - operation was also very necessary and would have been very helpful. They could have assisted the mujahideen in various ways by themselves.

K. H Khurshid, who was the secretary to Mohammed Ali Jinnah, and also Prime Minister of Azad Kashmir Government commented:
I firmly believe that Ayub Khan was not fully aware of the reasons for the war of 1965. Foreign Office, Home Ministry and some senior officers from the Ministry of Kashmir Affairs which included A. B Awan, Nazir Ahmed, Aziz Ahmed and Zulfikar Ali Bhutto, prevailed on him and assured him that it is only a small programme which would not lead to a war with India. Ayub Khan who offered India ‘joint defence’ would not have agreed to a full scale war with India.... These men wanted to weaken Ayub’s hold on the government, and this is the real reason why he was so angry with them after the war.

Ayub Khan was assured by his advisors and the Foreign Minister, Z.A. Bhutto, that India would not cross the international boundary to attack Pakistan. The Indian leaders and ministers were clearly saying that if Pakistan did not stop its adventure in Kashmir, then the conflict could spread to other areas. But Pakistani leaders did not take these threats seriously until the direct Indian attack on the Pakistani cities of Lahore and Sialkot in order to release the pressure on the retreating Indian forces in Kashmir.

Some critics say that the operation was "deliberately mis-planned to topple or weaken Ayub Khan". This has been very controversial, but whatever its real motives, it resulted in a full scale war between India and Pakistan. The Security Council arranged a cease fire on 23 September 1965.



General Musa Khan is the author of his autobiography, Jawan to General and "My Version". He died in 1991.

Genghis khan and Mongols

The knights at their tournaments, in their finery, armor and emblems of ancestry, believed they were the foremost warriors in the world, while Mongol warriors thought otherwise. Mongol horses were small, but their riders were lightly clad and they moved with greater speed. These were hardy men who grew up on horses and hunting, making them better warriors than those who grew up in agricultural societies and cities. Their main weapon was the bow and arrow. And the Mongols of the early 1200s were highly disciplined, superbly coordinated and brilliant in tactics.

The Mongols were illiterate, religiously shamanistic and sparsely populated, perhaps no more than around 700,000 in number. Their language today is described as Altaic -- derived from the Altay mountain range in western Mongolia - a language unrelated to Chinese. They were herdsmen on the grassy plains north of the Gobi Desert and south of Siberian forests. Before the year 1200, the Mongols were fragmented, moving about in small bands headed by a chief, or khan, and living in portable felt dwellings, called by the Mongols " ger." The Mongols endured frequent deprivations and sparse areas for grazing their animals. They frequently fought over turf, and during hard times they occasionally raided, interested in goods rather than bloodshed. They did not collect heads or scalps as trophies and did not notch wood to record their kills.

From his late teens to age thirty-eight in 1200, a Mongol named Temujin (Temüjin) rose as khan over various families. He was a good manager, collecting people of talent. He was vassal to Ong Khan, titular head of a confederacy better organized than other Mongol clans. Temujin joined Ong Khan in a military campaign against Tatars to their east, and following the success of this campaign Ong Khan declared Temujin his adoptive son and heir. Ong Khan's natural son, Senggum (Senggüm), had been expecting to succeed his father and plotted to assassinate Temujin. Temujin learned of this, and those loyal to Temujin defeated those loyal to Senggum. Temujin was now established as the head of what had been Ong Khan's coalition. And in 1206, at the age of 42, Temujin took the title Universal Ruler, which translates to Genghis Khan, and he addressed his joyous supporters thanking them for their help and their loyalty.

Like peoples elsewhere, Genghis Khan's subjects saw themselves at the center of the universe, the greatest of people and favored by the gods. They justified Genghis Khan's success in warfare by claiming that he was the rightful master not only over the "peoples of the felt tent" but the entire world. Genghis Khan continued organizing. He improved his military organization, which was also to serve as a mobile political bureaucracy, and he broke up what was left of old enemy tribes, leaving as ethnically homogeneous only those tribes that had demonstrated loyalty to him. He created a body of law that he was to work on throughout his life. The kidnapping of women had caused feuding among the Mongols, and, as a teenager, Temujin had suffered from the kidnapping of his young wife, Borte. After devoting himself to rescuing her, he made it law that there was to be no kidnapping of women. He declared all children legitimate, whomever the mother. He made it law that no woman would be sold into marriage. The stealing of animals had caused dissension among the Mongols, and Genghis Khan made it a capital offense. A lost animal was to be returned to its owner, and taking lost property as one's own was to be considered thievery and a capital offense. Genghis Khan regulated hunting -- a winter activity -- improving the availability of meat for everyone. He introduced record keeping, taking advantage of his move years before to have his native language put into writing. He created official seals. He created a supreme officer of the law, who was to collect and preserve all judicial decisions, to oversee the trials of all those charged with wrongdoing and to have the power to issue death sentences. He created order in his realm that strengthened it and his ability to expand. 
Conquests in Northern China

Genghis Khan moved to secure his borders. To his south he made an alliance with the Uighurs, who were closer than the Mongols were to the Silk Road and to wealth. He married his daughter to the Uighur Khan, and the Uighur Khan brought to the wedding party a caravan laden with gold, silver, pearls, brocaded fabrics, silks and satins. The Mongols had only leather, fur and felt -- a humiliation for a master of the entire world. 

Genghis Khan needed booty to pay troops securing his northern border and subduing an old enemy there, the Merkits . He acted on his mandate as the rightful ruler of the entire world and attacked the rulers of farmers and herders in northwestern China, the Tangut, who had much in goods like the Uighur Khan. In warriors the Mongols were outnumbered two to one, and they had to learn a new kind of warfare, against fortified cities, including cutting supply lines and diverting rivers. Genghis Khan and his army were victorious, and in 1210 Genghis Khan won from the Tangut recognition as overlord.

Also in 1210, the Jin dynastry of Jurchen people, who ruled that part of northern China that included Beijing, sent a delegation to Genghis Khan demanding Mongol submission as vassals. The Jin dynasty controlled the flow of goods along the Silk Road, and defying them meant a lack of access to those goods. Genghis Khan and the Mongols discussed the matter and chose war. Genghis, according to the scholar Jack Weatherford, prayed alone on a mountain, bowing down and stating his case to "his supernatural guardians," describing the grievances, the tortures and killings that generations of his people had suffered at the hands of the Jurchen. And he pleaded that he had not sought war against the Jurchen and had not initiated the quarrel. [note] 



In 1211, Genghis Khan and his army attacked. The Jurchen (Jin) dynasty had a large and effective army but they were hard pressed by both the Mongols and by a border war with the Tangut. They were also under attack by Chinese from south of the Yangzi River, the Southern Song emperor wishing to take advantage of the Jurchen-Mongol conflict to liberate northern China. But the Jurchen drove the Chinese armies into retreat. The Mongols were benefiting from China having failed during the previous century to make itself a strong military power. They benefited too from the Jurchen (Jin) dynastry ruling conquered people. The Mongols used divide and conquer tactics, using benevolence toward those who sided with them and terror and bloodshed against those who did not. They ravaged the countryside, gathering information and booty and driving populations in front of them, clogging the roads and trapping the Jurchen within their cities, where the Jurchen (Jin) dynasty was subject to revolts. The Mongols used conscripted labor in attacking cities and in operating their newly acquired Chinese siege engines. 

Against the Jurchen the Mongols had an advantage in diet, which included a lot of meat, milk and yogurt, and they could miss a day or two of eating better than Jurchen soldiers, who ate grains. Genghis Khan and his army overran Beijing and pushed into the heartland of northern China. Military success helped as people acquired the impression that Genghis Khan had the Mandate of Heaven and that fighting against him was fighting heaven itself. The Jurchen emperor recognized Mongol authority and agreed to pay tribute. 

After six years of fighting the Jurchen, Genghis Khan returned to Mongolia, leaving one of his best generals in charge of Mongol positions. Returning with Genghis Khan and his Mongols were engineers who had become a permanent part of their army, and there were captive musicians, translators, doctors and scribes, camels and wagonloads of goods. Among the goods were silk, including silken rope, cushions, blankets, robes, rugs, wall hangings, porcelain, iron kettles, armor, perfumes, jewelry, wine, honey, medicines, bronze, silver and gold, and much else. And goods from China would now come in a steady flow. 

The Mongols were happy to be back from China, their homeland higher in elevation, less humid and cooler. As eaters of meat and sparsely populated they felt superior to people in northern China, but they liked what China had to offer, and at home there was change. The continuing flow of goods from China had to be administered and properly distributed, and buildings had to be built to store the goods. Success in war was changing the Mongols - as it had the Romans and the Arabs.
Into Afghanistan and Persia 

Genghis Khan wanted trade and goods, including new weapons, for his nation. A Mongol caravan of several hundred merchants approached a recently formed Khwarezmid Empire, between Persia to Central Asia. The sultan there claimed that spies were in the caravan. Genghis Khan sent envoys. The sultan received them by having the chief of the envoys killed and the beards of the others burned, and he sent these others back to the Mongols. Genghis Khan retaliated, sending his army westward. In the coldest of months the Mongols rode across the desert to Transoxiana with no baggage, slowing to the pace of merchants before appearing as warriors before the smaller towns of the sultan's empire. Their strategy was to frighten their opponents into surrendering without battle, benefiting his own troops, whose lives he valued. Those frightened into surrender were spared violence, those who resisted were slaughtered as an example for others, which sent many fleeing and spreading panic from the first towns to the city of Bukhara. People in Bukhara opened the city's gates to the Mongols and surrendered. Genghis Khan told them that they, the common people, were not at fault, that high-ranking people among them had committed great sins that inspired God to send him and his army as punishment. The sultan's capital city, Samarkand, surrendered. His army surrendered, and he fled. 

Genghis Khan and his army pushed more deeply into the sultan's empire -- into Afghanistan and then Persia. It is said that the caliph in Baghdad was hostile toward the sultan and supported Genghis Khan, sending him a regiment of European crusaders who had been his prisoners. Genghis Khan, having no need for infantry, freed them, with those making it to Europe spreading the first news of the Mongol conquests. Genghis Khan had 100,000 to 125,000 horsemen, with Uighur and Turkic allies, engineers and Chinese doctors -- a total of from 150,000 to 200,000 men. To show their submission, some offered food to the Mongols, and Genghis Khan's force guaranteed them protection. Some cities surrendered without fighting. In cities the Mongols were forced to conquer, after killing its fighting men, Genghis Khan divided the survivors by profession. He drafted the few who were literate and anyone who could speak various languages. Those who had been the city's most rich and powerful he wasted no time in killing, remembering that the rulers he had left behind after conquering the Tangut and Jurchen had betrayed him soon after his army had withdrawn. 

The Mongols did not torture, mutilate or maim, but their enemies did. Captured Mongols were dragged through streets and killed for sport and to entertain city residents. Nor did the Mongols did not partake in the gruesome displays of stetching, emasculation, belly cutting and hacking to pieces that European rulers often resorted to elicit fear and discourage potential enemies -- as was soon to happen to William Wallace on orders from England's King Edward I. The Mongols merely slaughtered, preferring to do so at a distance. [COMMENT]





The city of Nishapur revolted against Mongol rule. The husband of Genghis Khan's daughter was killed, and, it is said, she asked that everyone in the city be put to death, and, according to the story, they were. 
Into Azerbaijan, Armenia and Eastern Europe

While Genghis Khan was consolidating his conquests in Persia and Afghanistan, a force of 40,000 Mongol horsemen pushed through Azerbaijan and Armenia. They defeated Georgian crusaders, captured a Genoese trade-fortress in the Crimea and spent the winter along the coast of the Black Sea. As they were headed back home they met 80,000 warriors led by Prince Mstitslav of Kiev. The battle of Kalka River (1223) commenced. Staying out of range of the crude weapons of peasant infantry, and with better bows than opposing archers, they devastated the prince's standing army. Facing the prince's cavalry, they faked a retreat, drawing the armored cavalry forward, taking advantage of the vanity and over-confidence of the mounted aristocrats. Lighter and more mobile, they strung out and tired the pursuers and then attacked, killed and routed them. 

In 1225, Genghis Khan returned to Mongolia. He now ruled everything between the Caspian Sea and Beijing. He looked forward to the Mongols benefits of caravan trade and drawing tribute from agricultural peoples in the west and east. He created an efficient pony express system. Wanting no divisions rising from religion, he declared freedom of religion throughout his empire. Favoring order and tax producing prosperity, he forbade troops and local officials to abuse people. Soon again, Genghis Khan was at war. He believed that the Tangut were not living up to their obligations to his empire. In 1227, around the age of sixty-five while leading the fighting against the Tangut, Genghis Khan, it is said, fell off his horse and died. 

In terms of square miles conquered, Genghis Khan had been the greatest conqueror of all time -- his empire four times larger than the empire of Alexander the Great. The Mongol nation believed that he had been the greatest man of all time and a man sent from heaven. Among the Mongols he was known as the Holy Warrior, and not unlike the Jews, who continued to see hope in a conquering king (messiah) like David, Mongols were to continue to believe that one day Genghis Khan would rise again and lead his people to new victories.
Mongols to the Gates of Vienna

Late in the life of Genghis Khan, members of his family fought over who was to be his heir. To end the dispute, Genghis Khan chose his third son, Ogedei (pronounced oh-go-day). And in 1229, after Genghis Khan's death, a great Mongol assembly confirmed the succession of Ogedei as the Great Khan. Ogedei Khan began his rule aiming to live up to his mandate as ruler of the world. In earnest he began drafting conquered people into his armies. Around one in ten young men from agricultural societies went into the Mongol infantry or to assist in siege warfare against fortified cities. And tent dwellers (nomadic herdsmen) joined the Mongol cavalry.

In 1231, Ogedei sent an army to police Korean defiance of an agreement made in 1218 to pay annual tribute. In 1232, the Koreans rebelled and a struggle ensued that was to last for decades. Ogedei Khan also sent his armies against the Jurzhen, and in 1234 his armies completed the conquest of northern China. In the mid-thirties Ogedei sent armies against Slavic principalities in Eastern Europe, but resistance by the Asiatic tribes between the Volga and Ural rivers was greater than he had expected, delaying his plans of conquest west of the Ural Mountains. Finally, in 1237, his army pushed against the Russians, conquering the cities of Vladimir, Kolmna and Moscow in 1238. In December 1240, Ogedei's army entered the city of Kiev and reduced the city to ashes. The Mongols would dominate Russia into the 1400s. 

In Hungary and Poland the Mongols were outnumbered but tactically superior. They defeated several Hungarian armies. In early April, 1241, at the Battle of Lenica (Liegnitz) in Poland, they defeated an army that is said to have included heavily armored Teutonic knights. Dying in the battle was the most powerful of Polish dukes, Henryk II (Henry II). In December the Mongols crossed the Danube River and approached Vienna. Then, mysteriously to Europeans, the Mongols retreated from central Europe. To the Europeans it seemed they had been saved by a miracle. A myth was to rise among the Poles that their brave warriors saved Europe from the Mongols. In reality, the Mongol withdrawal was in response to Ogedei's death, on December 11. High ranking Mongol army leaders believed they had to return to confirm the selecting of a new ruler.
From Ogedei to Mongke the Reformer 

Ogedei was like some other sons of great men -- something less than his father. He was a profligate spender of money, burdening his conquered subjects with unpredictable increases in taxes for his sudden needs of money. And torn between duty and tiring of it, Ogedei drank so heavily that a functionary was assigned to count the number of wine goblets that he had emptied daily. He died at the age of fifty-six after binge drinking during a hunting trip. 

However burdensome the position, there was no shortage of young men from Genghis Khan's extended family eager to become the next Great Khan. Ogedei's widow, Toregene, began administering Ogedei's estate, ruling her late husband's realm in his name and acting as regent for her eldest son, Guyuk, in his late thirties. Military operations slowed, including a reprieve of the fighting in Korea. Fighting began among men in the extended family. In 1246, Guyuk was able to buy support and win selection as Ogedei's successor. He showered gifts on people whose support he continued to seek, from princes to lowly scribes, as if money was in endless supply. 

In 1246, Guyuk Khan received an envoy from Pope Innocent IV. In a letter carried by the envoy the pope ordered the Mongols to “desist” from their invasion of Europe. The pope offered a synopsis of the life of Jesus and Christianity's tenets, hoping to convert the great khan, and he described himself as having been delegated by God as having all earthly power and as the only person authorized by God to speak for Him. Guyuk Khan replied that God had given the Mongols, not the pope, control of the world, from the rising sun to the setting sun. God, he claimed, intended the Mongols to spread His commandments in the form of Genghis Khan’s Great Laws. And he sent back to the pope the demand that he, the pope, submit.

The Mongol Empire was subject to the same succession problems as other empires. Guyuk's short reign, from 1246 to 1247, ended with Guyuk dying mysteriously amid royal family squabbling. The selection of the new Great Khan went in 1251 to another of Genghis Khan's grandsons: Mongke. A plot by rivals to assassinate him at his coronation was uncovered, and this was followed by torture, purges, trials, confessions and much letting of blood -- purges within the royal family as well as among government officials. 

Mongke Khan attempted to establish efficiency in governing all of his subjects. The postal relay system was freed of being jammed by elites using it for their personal benefit. He established predictable taxation that permitted planning by growers. He demanded that local rule not interfere with productive work. The death penalty was to apply to officers who seized vegetables from the gardens of Chinese peasants. Princes were forbidden to issue orders without approval from the imperial court. Officials, civil and military, were forbidden to enter areas where they had no jurisdiction. Military campaigning was to be done without devastating agricultural land or devastating cities, actions seen as reducing potential tax revenues for the imperial treasury. Private property was to be respected. Theft and brigandage were to be punished, with death the punishment even for minor offenses.

Under Mongke Khan's, women could own property and pursue litigation. They served as auxiliaries in the military, remaining hidden in the encampment during combat but joining the fight if an emergency made that necessary. Clergymen and monks were exempted from labor on community projects. As under Genghis Khan, people were allowed to worship as they chose. Buddhism, Islam and Christianity flourished. And, in 1252, Mongke's regime made official the worship of Genghis Khan.
Baghdad and the Limits of Empire

In the 1250s, France's king, Louis IX was concerned about the Holy Land and hoped for an alliance with the Mongols in order to destroy Islam. The Mongols were not interested, but they did begin expanding from Persia toward Mesopotamia. To complete the rule of the world, Mongke sent one of his brothers, Hulegu, westward, and Mongke planned to lead the conquest of the whole of China. As Hulegu and his army were passing through Persia, they destroyed the Muslim sect known in Europe as the Assassins (Hashshashin), opening the Mongol's route to Baghdad, the largest and richest city in the Muslim world. 

Some Christians in Baghdad used the coming of the Mongols as an opportunity to free themselves from Muslim rule or to avenge past wrongs, and Mongol military leaders, as was their habit, used such conflicts to their advantage. Within Hulegu’s army were Christians and Shi’a Muslim, and they are said to have been the most fervent participants in attacking Baghdad’s Sunni Muslim inhabitants. In 1258, Baghdad was destroyed and many Sunni inhabitants butchered, while Christians and Shi’a Muslims were spared. The conquest of Baghdad ended the Abbasid caliphate there and Baghdad as an Islamic spiritual capital.

In 1259, Hulegu's army entered the great Syrian city of Damascus , Christians there greeting the Mongol army with joy. The Mongol army then headed southward toward Egypt , and they learned that even great empires under God had limits. In 1260, their advance was stopped by the Mamelukes of Egypt, near Nazareth. Taking revenge on the Christians for having allied themselves with the Mongols, the Mamelukes destroyed Crusader strongholds in the Middle East, the beginning of the end of the Crusaders there, leaving them only at the Mediterranean coast, at Acre, Tyre and Tripoli. 
Kublai Khan in China and to Japan

After two years of preparation, Mongke's army invaded China's Sichuan province. There, in 1259, Mongke died in battle. He was the last of the great khans ruling from Karakorum and the last to exercise authority over the entire Mongol empire. Another fight ensued over who was to become the Great Khan, and succeeding Mongke was a brother, to be known as Khubilai Khan, who had been fighting alongside Mongke in China. 

Others declared themselves the Great Khan and established independent kingdoms, bringing the division that had plagued other empires. From his capital, Beijing, Kublai Khan pursued the subjugation of southern China, attracted by its wealth, including grain surpluses and towns along China's southern coast that were prospering from seaborne trade. Kublai tried to persuade the Song emperor to subjugate himself peacefully, and when this did not happen Kublai drove his army of various ethnicities (including Chinese and Persians) deeper into China, while his navy, manned by Jurchen and Koreans, sailed south along China's coast. The drive took sixteen years, the conquest ending around 1276 -- the year after a tradesman from Venice, Marco Polo, arrived at Beijing.

Kublai Khan interfered little in China's economy, and Confucianists were left without much influence, giving Chinese merchants a temporary break with which to pursue trade. The Mongols assimilated little with the Chinese, Kublai not wanting his army of occupation fusing with the Chinese. Nevertheless, a little mixing between conquerors and the conquered took place -- mainly Mongol soldiers taking Chinese women.

After consolidating his rule in China, Kublai Khan sent envoys to demand tribute from Japan, and he threatened reprisals if the Japanese did not. From the palace at Kyoto the Japanese answered, claiming as other rulers did that their nation had divine origins. Therefore, they argued, Japan was not to be subject to anyone, and they began preparing a defense. Kublai believed that he could not permit the appearance of Japan defying him. In 1274, from southern Korea, he launched an assault -- a Mongol, Chinese and Korean force -- with 600 to 900 ships, 23,000 troops, catapults, combustible missiles, bows and arrows. Bad weather compelled the invasion force to return from Japan's southern-most major island: Kyushu. 

In the summer of 1281, Kublai Khan tried again, this time sending some 4000 ships. For fifty-three days the Japanese held the invaders to a narrow beachhead on Kyushu. Then a hurricane struck. The Mongols withdrew again, only half of his force making it back to China. The Japanese interpreted the hurricane as a god wind -- kami-kaze. Khubilai had found in the Far East the limits that Hulegu had found in the Middle East. His attempt to invade the Japanese was the last until 1945, at Okinawa, when kamikaze would also be a word of significance.