Animal Plants: Life Adapted to a Vacuum

"These remarkable creatures combine the characteristics of animals and plants and so I call them animal-plants. ..." "All right. Don't get angry. Just explain how your creatures avoid getting dried up like mummies." "That is simple. Their skin is covered with a glassy layer, thin and flexible but absolutely impermeable to gases and liquids and all kinds of particles, so that the creatures are protected from any loss of material. . . . Their bodies have appendages which look like wings and a...

 Gedankenexperiment

However, the subject need not be an esoteric one for a gedankenexperiment to be fruitful. My own favorite is Galileo’s proof that, contrary to Aristotle’s view, objects of different mass fall in a vacuum with the same acceleration. One might think that a real experiment needs to be conducted to test that hypothesis, but Galileo simply asked us to consider a large and a small stone tied together by a very light string. If Aristotle was right, the large stone should speed up the smaller one...

 Constant Surveillance Builds a Better Identity

There are some who argue that individuality suffers under universal surveillance. When everything about you is known, and you have little or no control over how your identity is presented to others, you become just another person in a mass of similar persons. With no way to define yourself, individuality is eroded. We all become everyman and everywoman, or so the argument goes. To the contrary, the amount of detail provided to everyone around us in a transparent society helps to show all of t...

 The Bell Jar

A famous experiment in high school physics involves putting an electric buzzer in a bell jar, a glass container from which the air can be removed by a pump. When the air is removed, the sound of the buzzer disappears. As early as the seventeenth century, it was recognized that sound needed some medium to travel in. In a vacuum, such as exists inside the bell jar, there is nothing to carry the sound waves, so you don't hear the buzzer inside. To be more specific, sound is a pressure wave, or d...