
Re: Cardinality of turning wheel
Posted:
Mar 2, 2013 9:17 PM


On Sat, 2 Mar 2013, netzweltler wrote: > On 2 Mrz., 20:39, quasi <qu...@null.set> wrote: > > netzweltler wrote:
> > >What is the cardinality of the number of revolutions of a > > >turning wheel, if there is no beginning and no end to it? > > > > For a wheel revolving forever (both past and future), the > > set of revolutions is in onetoone correspondence with the > > set of integers, hence has cardinality aleph0. > > Is this still true, if the wheel is revolving at infinite speed, > meaning, that we can see at least one revolution no matter how small > the time we are watching it?
No. In that case the wheel, necessarily composed of purely virtual fantasy, would have spun, in it's eternal life, aleph_1 times.
Riddle of the day. How long is eternity? aleph_0 years, aleph_1 days, aleph_2 seconds?

