Color is a visual phenomenon. Some would say that the essence of color is the qualia of seeing color (see Mary the color scientist). Qualia or no, it’s incorrect to make a direct association between color perception and the wavelength or frequency of light. They are related, of course. A source that produces monochromatic light…
Tag: physics
The definition of insanity
The definition of insanity is doing the same thing over and over and expecting different results. This well-circulated quote is often attributed to Albert Einstein. I find it somewhat strange in that that is clearly not “the definition of insanity”. Insanity has multiple definitions. “Sane” and “insane” come from the Latin word for health. In…
Most people can’t identify steam
Have you ever noticed that when you take a pot of boiling water off the heat, it stops bubbling but starts steaming profusely? The answer is technically no, because despite appearances that is not what is happening. Steam or water vapor, that is H2O in a gaseous state, is usually invisible. The visible white smoky…
Why do sunsets look like that?
During the day, the sky is blue and the sun appears a bright yellow. As the sun sets, it dims and reddens while the sky turns pink and orange. What causes that? You may have heard before that the sky’s blue color is due to something called Rayleigh scattering. As it turns out, the way…
How does a double boiler work? Phases and phase transitions in the kitchen
Phases of matter and chemical mixtures Under most normal circumstances, chemical compounds exist in one of three states or phases: solid, liquid, and gas. At normal atmospheric pressure, there is a specific temperature at which a given substance will transition from one phase to another. Many substances in the kitchen which are solid at room…
A casual intro to topics in relativity
Special relativity is a theory of motion developed primarily by Albert Einstein in the early 20th century. Its precursor was Galilean relativity, which basically states that velocities are relative. One of the key features special relativity is the speed of light c being a constant. This means its speed is not relative, and this has…
What is the Second Law of Thermodynamics?
The Second Law of Thermodynamics is one of the most misunderstood scientific laws. Stated briefly, the law says that entropy increases over time in an isolated system. The misunderstanding can come partly from not knowing what an isolated system is, but mostly comes from not knowing what entropy is. What is entropy? First, entropy is…
Feelin’ the vibes (literally)
Has this ever happened to you? You’re driving your car and pull up to a stoplight, and another car pulls up beside you absolutely blasting the bass from their sound system. That’s got to be an aftermarket subwoofer, you think to yourself. Even though the sound is muffled and you can’t hear a melody, the…
Why rockets don’t need to push against anything (it’s rocket science)
How can a rocket work in empty space without something to push against? While you may or may not be aware of the answer yourself, this question is perplexing to many people. I invite you to consider why this situation is confusing. I assure you it is not a matter of mere ignorance, and you…
thoughts on mind 