IS economics a science or not?

I was reading a blog post cant remember where which said that economics is not a science and shouldn't be treated like one by speculative investors.. I think that they where right! If you think about it science is a all bout reproducing the same results from multiple tests.. but this is not the same in economics because there are tons of different factors that are dynamic and influenced by human behavior.... Yeah psychology is the study of human behavior but it is hardly reliable.