Every day brings a fresh barrage of bewildering claims about science and technology. How non-scientists tell the difference between the hyperbole and those developments that are important? With a modest amount of critical thinking, an understanding of how science is practiced, and a qualitative understanding of the two most sacred principles in science — the first and second laws of thermodynamics — anyone can make the distinction. Critical thinking and the practice of science are not emphasized in undergraduate science courses for non-scientists, while exposure to the first and second laws is usually reserved for physical science and engineering majors. This book introduces non-scientists to these topics and provides detailed applications to a variety of topics.