How do metal detectors work? Metal detectors work by transmitting an electromagnetic field that energizes any metal near it. There are three different types of metal detector and they all work in slightly different ways. These different types are very low frequency (VLF) detectors, pulse induction (PI) detectors, and beat-frequency oscillator (BFO) detectors. VLF detectors […]
#388 How do metal detectors work? Read More »
What is the smallest thing an electron microscope can see? An electron microscope can see atoms that are 0.05 nanometers long. 0.05 nanometers is a very difficult number to imagine. How small is it? Well, a human hair is about 50,000 nanometers across. There are different types of microscopes. The basic type that students use
#387 What is the smallest thing an electron microscope can see? Read More »
How does body armor work? By breaking up the bullet and removing its kinetic energy. Armor has been around for a long time, but it has always had to adapt to the technology of weapons. In the Bronze Age, they had bronze armor because it was enough to stop a bronze sword blade. Then the
#386 How does body armor work? Read More »
How do LED lights produce different colors? By using different materials that produce light at different wavelengths. LED stands for Light Emitting Diode and they are very different to regular light bulbs. A lightbulb produces light by passing an electric current through a very thin metal filament. This filament has to have a very high
#383 How do LED lights produce different colors? Read More »
Why is glass transparent? Glass is transparent because light photons don’t have enough energy to excite the molecules in the glass. There are two things we need to look at here. What is glass and what is light? Glass is a non-crystalline amorphous solid. There’s a bit to unpack there. Non-crystalline refers to the structure
#381 Why is glass transparent? Read More »
What is a Scramjet? It is an air breathing jet engine that works at supersonic speeds. Right. There are three questions we need to unpack here. How does a jet engine work? How does a ramjet engine work? How does a scramjet engine work? A jet engine has fan turbines at the front of it
#377 What is a Scramjet? Read More »
How can paints be different colors? To make different colored paints, you need to add different materials for color pigments because different particles reflect different wavelengths of light. Our eyes pick up reflected light using photoreceptors that are sensitive to different wavelengths. These then travel to our brain, which associates them with a color. For
#376 How can paints be different colors? Read More »
How does a smoke detector work? There are two different types of smoke detectors, and they respond to different types of fires. There are photoelectric smoke detectors that respond to smoke from smoldering fires and there are ionization smoke detectors that respond to smoke from flaming fires. Photoelectric smoke detectors have a chamber that has
#372 How does a smoke detector work? Read More »
Why are steam burns worse than boiling water burns? Steam burns are more severe than boiling water burns because steam goes through a phase change when it touches your skin, and it can penetrate your pores. Water is made up of molecules and molecules are made up of atoms. These atoms each have electrons and
#367 Why are steam burns worse than boiling water burns? Read More »
Why does an elastic band stretch? Because it is made of long chains of polymers that would rather be tangled together than straight. Rubber is famous for its ability to expand and return to its original size without any damage. There are natural rubbers and synthetic rubbers. The English word “rubber” was first used in
#356 Why does an elastic band stretch? Read More »
