> Time is one of them, space (or area on earth’s surface) is another, and energy is a third
I would combine the last two and call them "mass" and that currency is just an abstraction for how much mass you "own".
> The most common trade is when a person can trade their time and their body’s energy.
With this example I would say they are trading time and sometimes mass. They are trading time by the duration they work for and in certain jobs taking time off the years of their life. They may also move somewhere for a job even though they don't like the place and they spend their time in an non-ideal location.
They mass comes into effect when they are using their own car and gas to get to work, if they have to pay for their own work clothes, etc.
I would combine the last two and call them "mass" and that currency is just an abstraction for how much mass you "own".
> The most common trade is when a person can trade their time and their body’s energy.
With this example I would say they are trading time and sometimes mass. They are trading time by the duration they work for and in certain jobs taking time off the years of their life. They may also move somewhere for a job even though they don't like the place and they spend their time in an non-ideal location.
They mass comes into effect when they are using their own car and gas to get to work, if they have to pay for their own work clothes, etc.