It has long been suspected by general relativists that physicists who do not specialize in general relativity (GR) believe that special relativity (SR) is incapable of modeling dynamics within accelerated reference frames. Consequently, many physicists may conclude that certain phenomena, such as time dilation due to acceleration, can only be…

In traditional introductory physics courses, concepts of distance, displacement, speed, velocity, scalars, and vectors are generally taught near the beginning of the course. However, students often contend with preexisting notions, such as the idea that speed and velocity are synonyms, which present some of the first conceptual hurdles that they…

Student misconceptions of the double-slit experiment (Fig. 1) are abundant. The most common ones that we observe include: (1) belief that constructive interference requires both pathlengths to be integer multiples of the wavelength ("L[subscript 1] = n[subscript 1][lambda]" and "L[subscript 2] = n[subscript 2][lambda]") rather…

The conical pendulum is a classic introductory physics problem for teaching circular motion--a topic about which students frequently carry alternative conceptions. As teachers provide lessons to untangle these conceptions, it is good to allow students to practice their new knowledge in varied settings. This is one possible experiment that builds…

The concept of redshift is very often used in teaching physics and astronomy, as well as in science public outreach. Redshift is an interesting topic, used to describe many physical processes such as the Doppler effect or the expansion of the universe. Nevertheless, there are unfortunately also misconceptions about redshift. When facing the…

In the past decade, we have witnessed the emergence of a large number of different computer-based animations and simulations that have the goal to foster better learning of different physics topics. Past studies have shown many benefits of animations and simulations, but for their efficient usage it is very important that teachers are well…

Many high school and first-year university courses include discussion of the magnetic effect of currents. Frequently discussed textbook examples include long, straight wires, circular current loops, and solenoids, partly because these examples are tractable mathematically. The solenoid naturally leads to discussion on magnetic materials since it…

The nature and cause of the phases of the moon are widely misunderstood. Perhaps the problem is a general decline in scientific literacy, or maybe it is the loss of direct and regular observation of the moon in society generally. Many people do not see the moon as a half-illuminated sphere. Adults are often surprised to realize that the moon can…

The floating and sinking phenomenon related to buoyant force can readily be observed in everyday life and easily demonstrated to young students. However, many students believe that the buoyant force is determined by the object's attributes, such as the shape (e.g., ship) or material (e.g., wood). As a result, students find it challenging to…

Every so often an article appears in the popular press pointing to the apparent confusion surrounding the topic of aerodynamic lift and alleging that even the "experts" don't fully understand it. This makes attention-grabbing copy, but it overstates the case. Actually, the science of lift is not in dispute. It is well understood in terms…

Before reading this essay, go to your kitchen and find a bottle of Italian salad dressing. Get one that has been sitting still for a while at a fixed temperature--that is, one in thermal equilibrium. You will find an oil-rich layer at the top of the bottle and a vinegar-rich layer at the bottom (see Fig. 1). But think for a moment before spreading…

Research in physics teaching has supported the use of analogies as an effective instructional tool that can be used to facilitate students' understanding of physics concepts. The effectiveness of analogies lies in that they allow students to form cognitive links between what they already know and what they are learning, harmoniously integrating,…

The success of films such as "Avengers: Endgame," "Black Panther," and "Captain Marvel" has established the superhero genre in modern popular culture. Many students will have seen these films, or at the very least they are familiar with a number of the superhero characters. In the physics classroom, content based on…

For many students, introductory physics is an enormous hurdle to cross in their educational careers. Studies show that many students struggle with basic vector concepts and hold misconceptions of fundamental principles like Newton's laws, ideas essential to the understanding of higher-order physics concepts and for achieving success in engineering…

The photoelectric effect is one of the key experiments taught during first- or second-year university and high school modern physics courses. It is usually the first experiment to introduce light quantization and the concept of photons as "packets of energy." Here, we want to point out a widespread mistake concerning the interpretation…