Reblogged from Small Dead Animals, this is a Very Interesting article about Inertia.
I didn't understand it, nor did my mad interlocutor, and anyone who claims otherwise is not being entirely honest. Despite a gyroscope's utter simplicity—it is, after all, nothing more than a wheel on an axle—it remains the most fascinating and mysterious device ever created. Spin up the wheel, place it on a pedestal, and there it stays, pointed at…?
That is the question. At what, exactly, is the gyroscope pointed? According to the law of inertia, objects tend to continue doing what they've been doing: If at rest, they remain at rest; if moving, they continue moving at the same speed in the same direction. The gyroscope also bends to inertia's will, but in confounding ways. Touch it, and the gyro opposes you by veering in unexpected directions. If it is spinning extremely rapidly, the gyroscope remains rigidly locked in the direction it has been set, its sights fixed on...Kiev—hence the term inertial guidance systems.
That is a fascinating point. One which it seems nobody is really paying much attention to. Much later in the article, the author says:
The greater obstacle is one of fashion. Today's cosmologists constantly wade into shallow philosophical waters if they align with tastes of the current scientific Pradas and Versaces. They worry about creating Big Bang models whose input parameters occur "naturally" rather than needing to be "fine-tuned" by hand. They consider the "cosmological constant problem"—why the "dark energy" driving the universe's expansion is some 125 orders of magnitude less than what you'd "expect"—to be the outstanding dilemma of their field. Physics or philosophy? Each year hundreds of papers are published on the string theory landscape and on the universe of universes—the multiverse. Each year dozens of conferences take place on particle physics or string theory. The only conference on Mach's Principle took place in 1993.
Inertia is unfashionable. Interesting.
As well, the article includes one of the first explanations I've ever seen on "frame dragging" that was understandable. Well worth reading the whole thing.