There don’t appear to be any isolated poles in our universe, or at least none have been found. That’s just the way it is. As a result of this situation, the only way to create magnetism is through its relationship with electricity. When you use electricity to create magnetic fields, you effectively create equal pairs of poles—as much north pole as south pole.
No. Blue light causes the photoconductor to conduct. When you use white light in a xerographic copier, it’s the blue and green portions of the light that usually do the copying. The red is wasted.
They assemble 4 colors, yellow, cyan, magenta, and black together to form the final image. The photoconductor creates charge images using blue, red, green, and white illumination successively and uses those images to form patterns of yellow, cyan, magenta, and black toner particles. These particles are then superimposed to form the final image, which appears full color. Naturally, the photoconductor used in such a complicated machine must be sensitive to the whole visible spectrum of light.
As one of my readers (Tom O.) points out, most modern color copiers are essentially scanners plus color printers. They use infrared lasers to write the images optically onto four light-sensitive drums, one drum for each of the four colors (some systems reuse the same drum four times).
I don’t know. That question has puzzled me for years. The mixture should find its molecules clinging together. They must contain something that keeps the oppositely charged systems separate from one another so that they don’t aggregate.
Actually, if you drive fast over a real speed bump, it’s not good for your wheels and suspension. The springs in your car do protect the car from some of the effects of the bump, but not all of them. However, imagine driving over a speed bump on a traditional bicycle—one that has no spring suspension. The faster you drive over that bump, the more it will throw you into the air.
First, magnets don’t involve charges, they involve poles. So the question should probably be “are all metals magnetically poled?” The answer to this question is that they are never poled—they never have a net pole. They always have an even balance of north and south pole. However, there are some metals that have their north and south poles separated from one another. A magnetized piece of steel is that way. Only a few metals can support such separated poles and we will study those metals in a few weeks.
Yes. The light sensitive particles in black-and-white photographic paper don’t respond to red light because the energy in a photon of red light doesn’t have enough energy to cause the required chemical change. In effect, electrons are being asked to shift between levels when the light hits them and red light can’t make that happen in the photographic paper. However, most modern black-and-white films are sensitive to red light because that makes roses and other red objects appear less dark and more realistic in the photographs.
Yes. Particles of light, photons, cause chemical changes in the film. You can work with some black-and-white films in red light because red light photons don’t have enough energy to cause changes in those films. However, color film and most modern black-and-white films require complete darkness during processing. If you expose them to any visible light, you’ll cause chemistry to occur.
They are generally more conducive. Black light is actually ultraviolet light and its photons carry more energy than any visible photon. They can cause chemical changes in many materials, including skin.
If the ball was pitched straight and true, the same way every pitch, good batters could hit every one. There is enough time in the wind-up and pitch for the batter to determine where and when to swing and to hit the ball just right. But the pitches vary and the balls curve. That limits the batter’s ability to predict where the ball is going. There aren’t any physical laws that limit a batter’s ability to hit every ball well, but there are physiological and mental limits that lower everyone’s batting average.