Many people associate physics with famous figures like Einstein or impressive high-tech experiments like the Large Hadron Collider. But physics isn't just something that takes place on a blackboard or in a lab, it's all around you. If you've ever wondered what causes lightning, how lenses form images or why magnets stick to your fridge, you've asked questions that can be answered by physics.
Over the past few centuries, discoveries in physics have made new technologies possible, and many of these technologies now play an integral role in your everyday life. If you use a microwave, a car, a cell phone, a refrigerator, a laser pointer or a blender, you're using machines that were made possible by discoveries in physics. From jet aircraft to generators, motors to magnetic resonance imaging (MRI), physics-based inventions are ubiquitous in modern life.
Electricity and Magnetism
Try to name all the devices in your home that rely on electricity, and you'll find it's a very long list. In the 19th century, research by physicists like Michael Faraday and Andre-Marie Ampere made it possible for humans to generate and use electricity for practical purposes. Physics is essential for designing and understanding the electric devices you have all around your house, including the computer you are using right now.
The light bulbs, microwave oven and cell phone in your home rely on electromagnetic radiation to operate. These devices were all made possible by 19th- and 20th- century advances like Maxwell's equations, a set of equations that combined many different observations about electricity and magnetism into a single coherent theory. The way your fluorescent light bulbs and the MRI machine at your local hospital work can be explained by a branch of physics called quantum mechanics, which deals with the behavior of matter at the atomic and molecular level.
Your refrigerator, your car and the power turbine at the local electric power plant are all heat engines; they either use heat to do work (or in the case of your refrigerator do work to transfer heat). The branch of physics that deals with the way heat engines work is called thermodynamics. But thermodynamics isn't just relevant to heat engines. You can use thermodynamics to understand why heat always flows from hot objects to cold ones (and never the other way around), why food coloring and water mix but water and oil don't and why table salt dissolves but limestone doesn't. These are just a few of the ways physics is relevant to your everyday life.