But is the circumference of the outer circle or inner circle 1m? The wire has a nonzero width.

If you ride 20 mph on a road with 35 mph traffic, going the opposite direction is a 55 mph closing speed. With traffic is only a 15 mph difference.

Not to mention people typically only scan for what they expect to see. My city has some bike lanes that go in both directions on one way streets. No way I use the bike lane going in the opposite direction because few people will be looking in the oncoming direction when at intersections.

Walking in the opposite direction makes sense because there is minimal difference in the closing speeds and a person can step sideways off the road to avoid danger.

If last measurement within half a pound, show previous measurement.

Most digital bathroom scales will repeat your last measurement if it hasn't changed by more than half a pound. I pick up a 1 lb soap bottle off the counter first, then measure again without it for my weigh in.

Customers really hate seeing if a scale has a little inaccuracy in back to back measurements, so they all build in this bullshitting.