1 Introduction to Science and the Realm of Physics, Physical Quantities, and Units

 

Why Study Physics?

What comes to mind when you hear the word physics? Maybe you picture a whiteboard full of confusing equations, or long lists of formulas to memorize. You wouldn’t be alone—many students approach physics with hesitation or even fear. But as you begin to explore this subject, you may find that physics is much more connected to your daily life—and your future career in the health sciences—than you ever expected.

Take a moment to consider the human body. Every movement you make, every heartbeat, every breath you take, and every medical device used in a hospital—all involve physics. Whether it’s understanding how a blood pressure cuff works, how ultrasound images are created, or how forces affect the movement of joints and muscles, physics gives us the tools to describe, predict, and improve the world around us.

While physics helps explain the motion of stars and galaxies, the same principles apply here on Earth in every hospital room, physical therapy clinic, or operating table. For instance, gravity—the force that keeps planets in orbit—is also what allows intravenous (IV) fluids to flow from a bag into a patient’s bloodstream. The principles that govern lasers in astronomy are the same ones used in laser surgery and optical scanning.

Now think about the technology used in healthcare today: X-ray imaging, MRIs, pacemakers, ventilators, and robotic surgical tools. These are all built on physics concepts. Even routine health monitoring tools like thermometers and pulse oximeters depend on a physical understanding of temperature, light, and pressure. And beyond devices, physics is also central to understanding biomechanics, fluid flow in the circulatory system, and energy transfer in metabolism and exercise.

Professionals in many health-related fields—from physicians and nurses to physical therapists, radiologic technologists, respiratory therapists, and biomedical engineers—use physics every day. For example, a respiratory therapist must understand how pressure and volume relate in the lungs, and a nurse might adjust the angle of a hospital bed based on how gravity affects blood flow.

In this course, you’ll start by exploring the history and foundations of physics—from ancient natural philosophy to the groundbreaking work of scientists like Isaac Newton. You’ll also become familiar with the systems of measurement and standards that allow scientists around the world to communicate accurately, and you’ll learn how to express uncertainty in a way that makes your observations meaningful and reliable.

Physics is not just a collection of formulas—it’s a way of thinking critically about how the world works. Whether you’re analyzing forces in a patient’s gait, understanding how heat is transferred in the body, or learning how sound travels through tissue in an ultrasound, physics will give you a deeper, more confident grasp of the science behind your future profession.