Physics is above all an investigative tool. Its dream is to measure, accurately and precisely, whatever it is that we're measuring. And it doesn't matter what we're measuring, as long as it's done well. When people think of physics they may well think of experiments that try to track the early minutes of the universe, or the time-bending journeys of subatomic particles so weird we're still only guessing if they exist. Sure, physics includes these things. In some ways, it's where physics comes into its own - measuring things that are off the human scale of experience. We as humans don't count stars when we look up at the night sky, at least not very well. But the human physicist can and will find a way to count them, if it will be useful. Physics can be applied to anything outside our own frail limits, usually in a way which implies great beauty and for many of us a childlike delight in this incredibly magnificent universe. But what about the things within our limits?

Let me find you some examples. Bushfires touch us in this country with more regularity than we'd like. They can be tragic, immediate, next-door. Suppose we want to watch for them in areas with not enough people to monitor them easily. Why not use a satellite? A 24-hour eye that can cover large amounts of land. Physicists everyday are working with the problem of using a camera several hundred kilometres away to give us information that can be meaningful in the here-and-now. We use these solutions and results, and others like them, to plan trips, to time gardening and laundry, or any other time you use a weather picture from the TV to organise your life. Here physicists are taking an immediate problem, using a solution outside the human scale, and translating the results back into our scale.

Another example. Archaelogy tells us about the way of life people had hundreds, thousands even millions of years ago. Their reconstruction of pictures comes from using sociological and other tools and ideas on data they've collected. But where does the data come from? A recent study in my department looked at lead pollution over historic periods. It came up with data showing that at a time period corresponding with the Roman Empire there were large amounts of lead pollution in the air, and that the lead emanated from mines in Southern Spain - some of which are still being worked today. In this case, the data wasn't interpreted any further. Archaeologists can take that and decide what to do with it, just like we decide what to do about what we see in the weather picture on the TV. The point is that the measurement has been made. Made accurately, made as well as it can be. And it means something to us as humans.

There are many other examples I could come up with, but for the sake of brevity won't. Suffice to say that physics is an investigative tool, and physicists are trained to approach problems in a way that no other discipline matches. Our solutions and ideas and approaches lead to many of the things that the people in this world who call themselves "ordinary" enjoy and even take for granted. In many ways physics is a tool for dealing with the society that we, Homo Consumer, have created, and it can give you insights into the everyday that you just wouldn't believe until they were harnessed for you. This is why so many of us work outside the confines of strict physics and under job titles other than "physicist" - its beauty is in its relevance to everything, and everybody, everywhere.