What is time? We can measure it but how can we define it?

Question

We live by the clock, it never stops, but a heartbeat does. So how do we know time won't eventually stop?

Answer 1

It can't be measured nor can it be defined, it does not exist, time is a man made concept. Earth is a mere speck in the universe. Why does it need time zones?

Answer 2

Time is Relative to the observer - see first link...

NB. time is quite well defined = see 2nd link...

Answer 3

In the strictest sense, time might eventually stop, but the Earth and everything we know about the universe will be so long gone by then that we won't care.  Until then, rest assured that time is a very real dimension, different in some ways from the spatial dimensions but similar in many of the most important ways.  Reaching a point where time stops would be a bit like reaching a point in space where you couldn't go forward anymore... except at the fringes of the known universe, it just wouldn't make sense.

Answer 4

A relative term which suggests the fourth diemension of any thing in space.