Metaphors Bind Concepts Together in Our Minds

We are told in school, quite correctly. that a metaphor suggests what a thing is like by comparing it to something else. And by the power of its suggestion. it so fixes a conception in our minds that we cannot imagine the one thing without the other: Light is a wave; language, a tree; God, a wise and venerable man; the mind, a dark cavern illuminated by knowledge. And if these metaphors no longer serve us, we must, in the nature of the matter, find others that will. Light is a particle; langu...

 An Eloquent Description of Science and Wonder

As I gathered information for this book, I was continually reminded of the reality that science, rooted as it is in the certainties of the physical world, is a process that necessarily unfolds over time. In school, science classes tend to work according to this linear model; there's a “beginning, middle, and end” to science investigations, no matter how hard teachers may fight the “cookbook” reductionism that threatens true scientific inquiry. Yet, in probing further, I came to unders...

 Energy from the Sun to Earth

It is a feature of the way the world is made that two protons together have less mass than two protons separately. This is a startling but indisputable fact. Weigh two protons separately, then weigh them together: the numbers don't match. The numbers differ by about 1 percent. This curious difference is not to be explained by some law of nature; it is a law of nature, as basic to the way the world works as any fact in our possession. The mass discrepancy is equivalent to an amount of energy g...

 Why Nothing Can Go Faster Than the Speed of Light

Einstein's equation gives us the most concrete explanation for the central fact that nothing can travel faster than light speed. You may have wondered, for instance, why we can't take some object, a muon say, that an accelerator has boosted up to 667 million miles per hour—99.5 percent of light speed—and "push it a bit harder," getting it to 99.9 percent of light speed, and then "really push it harder" impelling it to cross the light-speed barrier. Einstein's formula explains why such eff...