Blog Archives

Richard Feynman’s Great Physics Lectures are Finally Available Online


Sometimes it takes decades for works that have had an immense impact to become easily and cheaply available, and this is especially true in the sciences. The difficulty of making a science or math text, with all of its special symbols and diagrams, browser-friendly poses a serious technical challenge. Since 1964, the “Feynman Lectures on Physics” have been a physics education classic, but now, the first volume is finally available online.

Richard Feynman is known not only as one of the great physicists of the twentieth century, but also as one of its great communicators who could explain the most complicated topic with rare clarity. His physics lectures, however, have traditionally been an expensive financial investment and used mainly at the undergraduate level. Now, ambitious high school students can try them out for free. We’ll be looking forward to the rest of the volumes becoming available in the near future.

Build Your Own Camera and Explore the Science and Engineering of Photography


As the number of gadgets and gizmos available for purchase grows, there is a decreasing number of opportunities for kids to build their own toys. It’s not only a matter of convenience; it’s become increasingly difficult for do-it-yourself projects to compete with cheap mass-produced products that incorporate fancy electronics. We’ve featured DIY resources and social networks in the past, but most of the instructions on these sites won’t help you build anything too fancy. Now, with the Bigshot that changes.

The project helps you build your own digital camera using a kit they provide, while exposing you to the science and engineering of photography. The accompanying site is extremely well-designed and is filled with educational materials covering everything from the camera construction process to the science of optics. Of course, the allure of building and owning your own digital camera is undeniable, and for $89 is worth exploring if you run a science club or simply want to excite the child engineers in your life.

How Transistors Work

Suppose you learned that transistors are a fundamental building block of modern electronics, and you decided to learn about how they function. If you looked at the first result in a google search you would see this Wikipedia article filled with technical details, but not that much beginner-friendly clarity. As with many such important concepts, explaining it at just the right level of detail to be both technical and accessible is a serious challenge.

To the rescue comes Derek Muller, creator of the Veritasium Youtube channel, who demystifies the idea behind transistors. His video features just the right type of animations and visual props to make a point without getting lost in technical details that would only be relevant to graduate students or scientists. If you’re interested in electronics, this six minute video is as good a starting point as any textbook or lecture.

The Five Second Rule: A Simple Everyday Question Leading To Quantum Mechanics and Biology

Sometimes the simplest question can lead down a deep rabbit hole to new worlds. How fast germs contaminate food that falls on the floor is a good example of such a question. When you start to think about it, you realize that you don’t quite now what it means for two objects to touch, and when you start analyzing the microscopic and then the quantum mechanical details, you cross multiple scientific disciplines.

This is the intellectual journey that Michael Stevens goes on in his video that debunks the “five second rule,” a popularly held belief that food that falls on a dirty floor is safe to eat if it is picked up quickly enough. One of the main benefits of this type of video is its ability to connect seemingly unrelated issues and motivate viewers to conduct their own thought experiments. You may think it’s a silly question, but you’re sure to be surprised by at least some aspects of the answer.

A Simple Animated Explanation of Free Falling and Zero Gravity

As children we first learn about the notion of weightlessness in outer space and the idea of zero gravity, but these concepts are actually a bit more nuanced than may appear. For example, why satellites orbit Earth instead of crashing into it because of Earth’s gravitational pull can be a mystery if you have never studied physics. The following TED Education animation does a good job of illustrating the basic principle behind orbiting objects without going into too many details.

If you’ve been exposed to high school physics, the Wikipedia article on weightlessness is uncharacteristically clear on some of the more advanced aspects of the subject. In particular, you may be surprised to learn that Einstein in developing his theory of relativity realized that gravitational interaction cannot be felt when all other forces are removed and this led him to consider the possibility that gravity is the result of the curvature of space. If you’re interested in the details of relativity and a modern interpretation of Newtonian mechanics, Leonard Susskind’s set of physics lectures is the best place to start.

10 Science Tricks for Entertainment and Further Exploration

In the era of iPhones and iPads, magic tricks involving everyday items may not be as exciting as they once were, but in a classroom they are still an effective teaching tool. Richard Wiseman has created a video featuring ten science-based stunts which are an excellent demonstrations of various principles of physics. Some of these tricks were once popularized by the great Martin Gardner and you can learn more about the science behind them in his books. Our favorite stunt, which is more mathematical than the others, involves cutting a hole in a small postcard so that a person can climb through it. Watch the video and start your next science conversation or class with one of the tricks in it. Any science knowledge gained from it is sure to be more memorable than a boring science textbook.

Richard Feynman on the Differences between Mathematics and Physics

As previously discussed, mathematics is not a science in the same way as physics, chemistry, and biology, yet because it is treated as a scientific discipline in school, students rarely understand it’s role. If you’re a math teacher, ask your students the following question: “Biology is the study of living organisms, physics is the study of matter, motion, energy, and forces, but what does math study?” You are certain to elicit a great deal of confusion.

In the following video, Richard Feynman, one of the great physicists of the twentieth century, attempts to answer the question by differentiating between the mental models of mathematicians and those of physicists (and by extension other scientists). Feynman, whose mathematical abilities stood out even among other elite physicists, was supremely qualified to compare the different approaches and to elucidate the peculiar nature of mathematical research. His lecture was recorded almost half a century ago, and lacks the polish of more modern science productions, but it more than makes up for it in both substance and Feynman’s impassioned lecture style. This is a must-see lecture for high school students who have an interest in a math or science career.

Vacuum Cleaners, Cannons, and the Quantum Mechanics of Empty Space

The force exerted by air molecules is something that we take for granted every day, but it is a surprisingly powerful force with equally surprising applications. For example, a vacuum cleaner “sucks” dirt in by creating a partial vacuum that allows the air outside the vacuum cleaner to push dirt into it. Similar reasoning can be used to create a vacuum cannon that relies on air pressure to eject a projectile at great (even supersonic) velocity. The following video from the Sixty Symbols Youtube channel illustrates this and provides further technical details.

If you’re interested in learning more about vacuums, Sixty Symbols has a follow up video that reveals their surprising quantum mechanical nature. You may be surprised to learn that a complete vacuum cannot really exist and that empty space actually contains energy. The conversational nature of the video doesn’t allow for a rigorous treatment of the subject, but instead offers an enticing glimpse into the exciting world that research scientists get to explore.

Two Minutes of Thermodynamics: Heat Versus Temperature

Sometimes a simple drawing or animation is all that it takes to understand a previously confusing idea. A good illustration of this principle is the following video by Henry Reich which does a good job of explaining the difference between heat and temperature. These two concepts are clearly related but students often erroneously equate them, especially when they first start thinking about them in science class.

A similar, but much older animation from the Eureka! Science series also addresses this thermodynamics issue, but from a slightly different perspective. If you have five minutes to spare, you won’t regret getting a better grasp of this fundamental area of physics.

A Book on Modern Mathematics for Elementary School Students

modern math for elementary school

Sadly, professional mathematicians play a mostly decorative role in shaping mathematics education. Research is simply a much more attractive activity than the politics of education reform and curriculum development. There are not enough incentives to lure most mathematicians away from their academic responsibilities and to push them into improving the quality of mathematics instruction, unless of course, those mathematicians are parents concerned with the quality of their children’s education. That is the story of Oleg Gleizer, a mathematician and parent who could not find a suitable mathematics program for his five year old son and decided to take matters into his own hands.

The result of his effort is the book Modern Math for Elementary Schoolers [PDF], which bridges the gap between the requirements of school mathematics and a deeper conceptual understanding of the subject. This is not a replacement for a good textbook because it does not cover all of the standard topics, but it is a vital supplement that opens the doors of high level mathematical thinking to elementary school students. For example, the first chapter introduces number partitions, parity, and other basic properties of numbers using Young diagrams, which are important objects in advanced mathematics. This approach actually makes the topic more visual and easier to understand even though advanced ideas lurk in the background. Other topics that are deeply yet playfully explored in the book include straight line geometry (and its connection to physics), straight edge and compass constructions, modular arithmetic, and algorithms.

In effect, Modern Math for Elementary Schoolers [PDF] is a lively guide and collection of problems for parents and teachers who want to weave a non-superficial mathematics, computer science, and physics narrative into their teaching. Contrary to the title of the book, a significant part of the material in the book will be relevant to students of any age. If you’re looking for something similar to Math from Three to Seven, this book fits the bill perfectly.

Photo Credit: faungg