For instance, the motion of a spacecraft, regarding its orbit and attitude , is described by the relativistic theory of classical mechanics, while the analogous movements of an atomic nucleus are described by quantum mechanics.
According to the NHS, the average Briton walks between 3,000 and 4,000 steps a day - significantly less than the Fitbit target. Yet many people do significantly more, and for them 10,000 steps might not be much of a target.
By the end of the week you will know your average daily steps. You might be surprised how many, or how few, steps you get in each day. A reasonable goal is to increase average daily steps each week by 500 per day until you can easily average 10,000 per day.