Another week, another hangout with Rhett. In which we actually fielded a couple of questions from readers on Twitter, about the reason for inertia and a kind of meta-question. More audience questions would, of course, be welcome.
A couple of links to things that came up:
Mach's Principle, a past attempt to explain the origin of inertia.
Newton's famous refusal to explain gravity, "Hypotheses non fingo." Sir Isaac was second to none in his mastery of snotty condescension.
Aatish Bhatia's post about a new meta-analysis of "active learning" studies showing that traditional lectures are less effective than active methods.
More like this
When I was talking about balancing a stick, I mentioned the moment of inertia. Moment of inertia is different than mass, but I like to call it the "rotational mass". What does mass do?
The playground outside SteedlyKid's day care, amazingly in this litigious age, has a merry-go-round, a rotating disc with a really good bearing. The kids can really get the thing flying, which is kind of terrifying at times.
Maybe you have seen this trick. Basically, you hold by supporting it with two fingers from the bottom. You then move your hand around to keep it balanced while the stick is vertical. It is really not as hard as it looks. Also, there are two things that can make your job easier.
If you live on flat terrain like I do, you might not get a chance to experiment with your car coasting down hills in neutral. It's kind of dangerous even if you can. But let's say you're on the top of your driveway and beginning from a stop you coast down to the street below.
I think one must find first the reltions between inertia and "pure" space.