Skip to main content
How to Build a Projector for Casting Object Shadows onto Walls
Description
Discover how to build a simple home projector based on the principles of optics and the reflection of light from everyday objects. This experiment demonstrates how using a converging lens allows you to project images onto a wall, while providing an understanding of the relationship between the position of the object, the projector lens, and the resulting image.
Original title
איך לבנות מקרן המקרין דמויות של חפצים על הקיר?
גלו כיצד לבנות מקרן ביתי פשוט המבוסס על עקרונות האופטיקה והחזרת אור מחפצים יומיומיים. הניסוי מדגים כיצד שימוש בעדשה מרכזת מאפשר להקרין דמויות על הקיר תוך הבנת הקשר בין מיקום העצם, עדשת המקרן והתמונה המתקבלת.
Video transcript
This video has no captions on YouTube.
You can generate an approximate AI transcript from the video metadata.
Related Videos
2:31
No Subtitles
🇮🇱 Hebrew
Food Waste
Credit: מכון דוידסון לחינוך מדעיFood waste is a global crisis with far-reaching environmental and economic consequences, ranging from greenhouse gas emissions to the depletion of precious natural resources. Discover what truly happens to the food we throw away, how it fuels the climate crisis, and explore effective strategies to combat this phenomenon starting right in our own kitchens.3:07
No Subtitles
🇮🇱 Hebrew
The Hedgehog Incident
Credit: מכון דוידסון לחינוך מדעיImagine a hybrid creature that merges the traits of the animal and plant kingdoms; this video presents a visual model demonstrating what a cross between a hedgehog and a lush green lawn might look like. This serves as a unique opportunity to discuss the fundamental biological differences between animals and plants, as well as the distinct characteristics that define each of nature's kingdoms.3:51
No Subtitles
🇮🇱 Hebrew
Daniel Asks: Why Are We Afraid of the Dark
Credit: מכון דוידסון לחינוך מדעיThe fear of the dark is an ancient evolutionary survival mechanism designed to protect us from predators lurking in places we cannot see. Our brains tend to fill in missing visual information with our imagination, which triggers a sense of danger and anxiety in children and adults alike. Understanding the evolutionary roots of this fear helps us confront it in a more rational and calming manner.2:48
No Subtitles
🇮🇱 Hebrew
I'm Not Buying It
Credit: מכון דוידסון לחינוך מדעיIs our consumer behavior based on rational choices, or is it driven by cognitive biases and marketing manipulations? This video explores the psychological mechanisms that compel us to buy products we don’t need and the ways our brains respond to advertising and special offers. Discover the scientific explanations behind our shopping habits and learn how to identify the traps set for us on the way to the checkout counter.2:52
No Subtitles
🇮🇱 Hebrew
Capsules of Hope
Credit: מכון דוידסון לחינוך מדעיFecal transplants are a medical treatment designed to restore the gut's bacterial population, particularly in cases of resistant and life-threatening infections. The development of capsules containing "good" bacteria now allows patients to replace invasive traditional procedures with a simple pill. This process helps restore biological balance to the digestive system, offering new hope to patients suffering from chronic gastrointestinal issues.3:20
No Subtitles
🇮🇱 Hebrew
Edible Glitter
Credit: מכון דוידסון לחינוך מדעיDiscover how you can create edible glitter to decorate food using common household ingredients and an understanding of the scientific principles behind them. This video demonstrates the simple process of making food-safe glitter based on starch or sugar, all while maintaining a shimmering, festive appearance. Learn about the connection between the structure of a material and the way it reflects light.3:35
No Subtitles
🇮🇱 Hebrew
The Science of Laughter and the Surprising Humor of Brain Surgery
Credit: מכון דוידסון לחינוך מדעיWitness the fascinating process that unfolds within the brain during laughter and discover how electrical stimulation of specific regions can trigger uncontrollable outbursts, even in the midst of surgery. The video demonstrates the intricate connection between emotion, physiological response, and neural activity, offering a rare glimpse into an operating room where patients remain fully conscious.2:06
No Subtitles
🇮🇱 Hebrew
Floating Paintings
Credit: מכון דוידסון לחינוך מדעיDiscover how to bring your drawings to life using nothing more than a whiteboard, water, and an erasable marker. This experiment demonstrates the unique properties of dry-erase ink, which is insoluble in water and does not adhere strongly to surfaces. This lack of adhesion allows the drawing to detach in one piece and float on the water's surface, powered by the force of buoyancy.4:09
No Subtitles
🇮🇱 Hebrew
Daniel Asks: What is the Moon
Credit: מכון דוידסון לחינוך מדעיDaniel sets out on a journey through space to understand what the Moon—Earth’s constant companion—actually is and how it was formed. A simple and fascinating explanation of the celestial body closest to us, its relationship with other planets, and the unique characteristics that make it a natural satellite.3:42
No Subtitles
🇮🇱 Hebrew
Daniel Asks What Is a Shadow
Credit: מכון דוידסון לחינוך מדעיDiscover how shadows are formed through a simple demonstration that explains the interaction between a light source and an opaque object. Daniel demonstrates why a shadow takes the shape of the object blocking the light, what happens when light strikes at different angles, and how the familiar zones of darkness are created.3:23
No Subtitles
🇮🇱 Hebrew
Daniel Asks: What is a Falling Star
Credit: מכון דוידסון לחינוך מדעיDiscover the spectacular phenomenon of the "shooting star," which is not a star at all, but rather a tiny particle of dust or space rock entering Earth's atmosphere at breakneck speeds. This video explains how friction with the air generates immense heat and the shimmering trail of light we see in the night sky. It also provides a simple and fascinating breakdown of the differences between a meteoroid, a meteor, and a meteorite.3:18
No Subtitles
🇮🇱 Hebrew
Why Is the Ocean Salty?
Credit: מכון דוידסון לחינוך מדעיThe salinity of the oceans stems primarily from the erosion of rocks on land by slightly acidic rain, which dissolves minerals and carries them through rivers into the sea. As water evaporates from the ocean surface, these salts are left behind, their concentration steadily increasing over billions of years. Additional sources of salt include hydrothermal vents on the seafloor and underwater volcanic activity.2:33
No Subtitles
🇮🇱 Hebrew
Can you play tennis while sitting down
Credit: מכון דוידסון לחינוך מדעיThis video explores the physics of wheelchair tennis, showcasing the unique challenges faced by Paralympic athletes. While the rules closely mirror those of conventional tennis, players must master the art of maneuvering their chairs while simultaneously striking the ball—a feat that demands explosive power, agility, and extraordinary technique. You will discover how the science and engineering behind the chair empower players to achieve impressive levels of precision and power on the court.2:18
No Subtitles
🇮🇱 Hebrew
Craters in Space
Credit: מכון דוידסון לחינוך מדעיDiscover how impact craters are formed across the celestial bodies of our solar system, from our Moon to the most distant planets. This video demonstrates the physical processes that occur during asteroid and meteorite collisions, explaining why the Moon’s surface is far more scarred than that of the Earth. It is a window into the violent and fascinating history of our cosmic neighborhood.1:07
No Subtitles
🇮🇱 Hebrew
What are Greenhouse Gases
Credit: מכון דוידסון לחינוך מדעיGreenhouse gases are atmospheric components that trap heat near the Earth's surface—a process without which our planet would be too frozen to sustain life. However, human activity is increasing the concentration of these gases, leading to accelerated global warming and significant climate change. Discover the physical mechanisms behind the greenhouse effect and its profound impact on our world.3:19
No Subtitles
🇮🇱 Hebrew
Pickled cucumbers
Credit: מכון דוידסון לחינוך מדעיDiscover the fascinating science behind the crunch of a pickle and the chemical processes that occur during the pickling process. This video explores how the use of calcium chloride preserves the cucumber’s cellular structure and prevents it from softening, alongside detailed explanations of the interactions between enzymes and pectin.3:32
No Subtitles
🇮🇱 Hebrew
Submarine Bath Bomb
Credit: מכון דוידסון לחינוך מדעיDiscover what happens when you drop a bath bomb into water and explore the chemical reaction behind its vibrant, colorful display. This process demonstrates how solid substances like citric acid and baking soda react with one another in a liquid to release carbon dioxide gas. It is a simple and engaging science project that explores states of matter, solubility, and exothermic processes.2:34
No Subtitles
🇮🇱 Hebrew
The Fish Miracle
Credit: מכון דוידסון לחינוך מדעיBy adding simple ingredients to water, one can create a striking simulation of glowing fish moving within a glass vessel. The experiment demonstrates fundamental chemical principles of density and molecular interaction to produce a visual effect reminiscent of bioluminescent creatures. It is a compelling way to make science accessible through a hands-on, immersive experience.4:07
No Subtitles
🇮🇱 Hebrew
The Cartesian Diver Mystery
Credit: מכון דוידסון לחינוך מדעיDiscover how to build a simple Cartesian diver using only a water bottle and a straw to demonstrate the fundamental physical principles of pressure and buoyancy. The experiment illustrates how squeezing the bottle compresses the volume of air inside the diver, causing it to sink or float in accordance with Archimedes' principle. It serves as an engaging, visual way to understand the relationship between density and pressure changes within a closed container.2:31
No Subtitles
🇮🇱 Hebrew
Preparing Human Cells for Microscopic Observation
Credit: מכון דוידסון לחינוך מדעיLearn how to prepare a slide of human epithelial cells from the oral cavity for microscopic observation. The video demonstrates the steps of gentle scraping, placing the sample on a microscope slide, and staining the nuclei with Methylene Blue to clearly distinguish the cell structure and its nucleus.Cookies & Privacy 🍪
We use cookies to improve your experience
For more information, see our Privacy Policy