Question: How is a rocket invented

Bernerd Fulanda answered on 12 Jul 2017:

Dear Haso
One of the first devices to successfully employ the principles essential to rocket flight was a wooden bird; Somewhere around the year 400 B.C., Archytas mystified and amused the citizens of Tarentum by flying a pigeon made of wood. Escaping steam propelled the bird suspended on wires. The pigeon used the action-reaction principle, which was not stated as a scientific law until the 17th century.
About 300 years after the pigeon, another Greek, Hero of Alexandria, invented a similar rocket-like device called an aeolipile. It, too, used steam as a propulsive gas.
During the latter part of the 17th century, the scientific foundations for modern rocketry were laid by Sir Isaac Newton (1642-1727). Newton organized his understanding of physical motion into three scientific laws which explain how rockets work and why they are able to work in the vacuum of outer space. Newton’s laws soon began to have a practical impact on the design of rockets. About 1720, a Dutch professor, Willem Gravesande, built model cars propelled by jets of steam. Rocket experimenters in Germany and Russia also began
During the end of the 18th century and early into the 19th, rockets experienced a brief revival as a weapon of war. The success of Indian rocket barrages against the British in 1792 and again in 1799 caught the interest of an artillery expert, Colonel William Congreve. Congreve set out to design rockets for use by the British military.
and therefore WAR became the main driver for rocket science