global warming definition. The term attached to the notion that the Earth's temperature is increasing due to the greenhouse effect. Note: Whether global warming is actually happening is a subject of scientific debate.
Like jet airplanes, space rockets work on a principle called action and reaction (another name for Newton's third law of motion). The massive force (action) generated by hot gases firing backward from a rocket's engines produces an equal force (reaction) that pushes the rocket forward through space.
If we develop a bicycle with a similar chain and sprocket arrangement in the front wheel so that it can work in a fashion as that of the rear wheels, it will definitely move backwards. But the thing is, instead of making it such a complex machine, we just turn back and move forward when actually we have to go backwards. Sounds much simpler and wiser.