CONTENTSPART A: Introduction: does the inertia of a body depend upon its energy content?PART B: The Toolkit: mathematical and physical assumptions PART C: The Thought Experiment and the Word ProblemPART D: The Derivation. Solving the Word ProblemPART E: Conclusion: Einstein's Style or How to not be a Crack Pot>

The gap between hypothesis and observation is never more evident than efforts to figure out howblack holes produce so many high-power X-rays.>

Wizards exist in real life, beyond the films and books of Harry Potter. They cook willow bark extract in car battery acid and wood alcohol and convert it into a pleasant-smelling component of candy or of a rubbing compound. In their glassware, petroleum products turn into life-saving medicines. >

If you want to design new materials that are durable, lightweight and environmentally sustainable, it makes sense to look at old kinds: Natural composites, such as bone. Bone is strong and tough because its two constituent materials, soft collagen protein and stiff hydroxyapatite mineral, are arranged in complex hierarchical>

A Mojave rocket company, an asteroid hunter, and a web pundit walk into a conference.  The badge person says, "what is this some kind of joke?"Okay, we gotta get to space somehow.  Here's what's new in the private space race industry.  What ties these 4 newsbits together is it's all about having fun>

X-ray experiments have found chemical traces of the original 'dinobird' Archaeopteryx and dilute traces of plumage pigments in a 150 million-year-old fossil. Only 11 specimens of Archaeopteryx have been found, the first one consisting of a single feather. Until a few years ago, researchers thought minerals would>