Economy as a science

First of all, what is the science and how could we define it?
The very definition of science is “ discipline which has for object the study of facts, tested relationships”. The scientific revolution was a period when discipline as biology, physics, astronomy, chemistry, etc used reason and knowledge instead of religion, superstition and beliefs. Indeed, since then, Science is based on hypothesis, which has to be tested and experienced. Like physics sciences, economy wants to be recognize as a science too. But, the definition of science, which treats of economy, has a first problem: the very name “science”. Indeed, some people use the word “ economic”, and other the word “ economy” and other again the word “ science of economy “ or “ economics sciences”. To tell the truth, expression the most exactly could be the economic science as we say political science or socials science. But if economy is a science why using these two words? So, we use only the term “ economy” to refer to as well the studied thing than the science which studies its, as well as the art to apply laws and recognized mechanisms front of problem to solve for humans activities. Economy is a science because it is part of human sciences. Human sciences encompasses administration, anthropology, geography, history, political science, psychology, science of religions, sociology and so economy. As science, the aim of economy is to be able to understand and to have certainties on the human behaviour regarding production, consumption and distribution. For it, economy researches consumer behaviour, formulates economic models and evaluates corporate strategies. Contrary to physics science, economists can almost never use controlled experiments to find facts, which can be tested. Indeed, economists just can explain the behaviour but they can’t say with certainty what it can be happen in the future. For example, the sub primes crisis wasn’t planned by economists. Also, economy