“It’s not rocket science, is it?!”
This now clichéd phrase, used to imply simplicity, has often annoyed me. There are two reasons for this, firstly, there isn’t really such a thing as rocket science; secondly, if there were such a thing, it would be relatively simple.
The subject often confused for rocket science is aerospace engineering, which is, to avoid insulting any engineers, an extremely complex and difficult subject. But engineering and science are two distinct disciplines. The main difference between the two fields was neatly described to me by an engineer-turned-biologist, who said:
“Scientists ask why, engineers ask how?”
A scientist uses scientific methodology to propose new theories; an engineer then uses these theories and applies them to a practical situation. Of course, there is a considerable amount of crossover in the subject matter, but the basic approach is where the difference lies.
Aerospace engineering was pioneered by Werner von Braun, who started out building rockets for the Nazis in WWII, before going on to work for NASA, designing the Saturn V launch vehicle, which was used to propel men to the Moon. It takes in to account everything required to build a functioning rocket, allowing it to be launched out of the Earth’s atmosphere, withstanding the harsh temperature and pressure changes, and still functioning correctly in outer space. It incorporates a huge number of areas of engineering, several of which have very complicated sounding names, like avionics and astrodynamics. Suffice to say, it takes a cleverer person than me to understand it.
So, what is rocket science? As far as I can tell, the only important ‘science’ involved in blasting a rocket into space is Newton’s third law of motion, which states that ‘every action has an equal and opposite reaction’.
That is to say, if an object applies a force to another object, the second object will apply the same force, back in the opposite direction. This is why, if you lean against a wall, it pushes back, supporting your weight.
So, if you fire up a dirty great engine and blast a huge amount of force downwards, the equal and opposite reaction will be to thrust the rocket upwards. If this force is great enough, the rocket will leave the atmosphere, boldly going where only a few men (and women) have gone before (not quite as catchy is it). The design of this engine and the amount of thrust required to push down, in order to lift the rocket are all questions of engineering, which is applying this scientific law to a practical situation.
So, when described as a science, this is a relatively simple concept. However, from an engineering point of view, it is extremely complex. Therefore, when someone says ‘it’s not rocket science, is it?!’ a perfectly valid response would be ‘it is that simple, but it certainly isn’t aerospace engineering!’ Unfortunately, this probably isn’t going to catch on.