When people ask me what is physics? I'll say something like "it is the study of the physical universe." Then maybe point to something nearby, say a light and explain how and why it works. I'll says physics describes all that you see around you in simple concepts. Then maybe talk about motion and Galileo and his studies of motion using inclined planes, maybe the Leaning tower of Pisa. Talk about Kepler and his study of Brahe's astronomical data to describe the motion of the planets. Then talk about Newton and his law of gravity. Further this with Newton and his three laws of motion. Stress how conceptually simple they are yet how powerful they are maybe giving an example of folks going to the moon and back. Newton second law, F = ma, then one can talk about forces and studies that show there are four forces and then what is mass, and what objects are made of like atoms and their structure. Always trying to emphasize how simple all of this is and how this was obtained from experiments. However most of the time it never works out this way since people either get bored or in most cases they start to ask lots of questions and hopefully I can answer them using simple concepts from physics. People are curious about the world around them. What I try to remember to say every now and then is that people have figured out and can explain just about everything they see around themselves and much more and how incredible it is for me to say this, and aren't humans amazing in that we can do such stuff! If you think about it this is quite an achievement of humans. If someone says physics is hard and people like Einstein do it, one can talk about these truly insightful people who figured out these laws and concepts. What makes people think that physics is hard is the mathematics that physicists use. But the ideas and concepts can be explained without math. We are very fortunate that we have physicists who can describe physics and its concepts very well to the public in books, television, movies, and the internet. I've learned a lot physics these days reading blogs from practicing physicists. I've mentioned some of these blogs in an earlier post.
If they say that the physics and math is hard, I might point to a woman who is outside our listening range and say figuring her out is hard compared to physics. That might draw a laugh but its very true. Figuring out a person is much more difficult than figuring out physics. Answering the question "will she go out with me?" is more harder to figure out than known physics. Understanding a person or a group of people is much more difficult than physics. Physics can describe the interactions among two particles very well. Try that with trying to figure out the interaction between two people. A much more difficult problem. Physics is easy compared to that.
As mentioned physics can describe the physical world very well. Applying the tools that physicist use in studying the physical universe to the study of an individual person or to the many body problem of the group dynamics of people is a worthwhile task. The two person interaction problem is much more difficult probably than trying to understand what a large group of people do. Physicists have researched such things as traffic flow and obtained scaling laws of cities are some thing that come to mind. Physicists starting back in the 50's used game theory to try and understand economics and in war gaming. I've read and heard for many years that Wall St. loves physicists. There was even a story going around about an experimental nuclear physicist who went to work on Wall St during his sabbatical and came back wealthy. I have no idea if its true but it is certainly plausible. Physicsist in the social sciences makes all kinds of sense. A recent post by one of my favorite physics bloggers Sabine Hossenfelder talks about this subject here. If one looks in jobs sections on various physics web sites there are faculty positions in physics department being offered to study big data. A cynical part of me says these are government supported positions to get physicists to work on big data projects so that their techniques can then be applied by the NSA in spying on us. But physicsist using their talents to help understand human behavior makes all the sense in the world. Such a project is that of physicists and others that they have set up at New York University to study New York City using all of the data that they can get from a variety of monitors all around the city such as traffic lights, taxi flow patterns, subway schedules, any sort of data they can use to help understand New York City dynamics. This was mentioned in the Back Page section of the March 2014 issue of APSNEWS.
But physics is easy compared to the human-human interaction.