The problem disclosed by Zeno’s Paradox is still there and the exactly same idea is still working well. Let’s see one of the modern versions of Zeno’s Paradox
1+1/2 +1/3+1/4+...+1/n +... (1)
=1+1/2 +(1/3+1/4 )+(1/5+1/6+1/7+1/8)+... (2)
>1+ 1/2 +( 1/4+1/4 )+(1/8+1/8+1/8+1/8)+... (3)
=1+ 1/2 + 1/2 + 1/2 + 1/2 + ...------>infinity (4)
Such an antique proof (given by Oresme in about 1360), though very elementary, can still be found in many current higher mathematical books written in all kinds of languages.
Here, with limit theory and technique, we see a “strict mathematically proven” modern version of ancient Zeno’s Paradox:
1, in Harmonic Series, we can produce infinite numbers each bigger than 1/2 or 1 or 100 or 100000 or 100000000000000000000 or… from infinite infinitesimals in Harmonic Series by “brackets-placing rule" to change an infinitely decreasing Harmonic Series with the property of Un--->0 into any infinite constant series with the property of Un--->constant (such as Un’ >10000000000000000000000000) ;
2, the “brackets-placing rule" to get 1/2 or 1 or 100 or 100000 or 100000000000000000000 or… from infinite items in Harmonic Series corresponds to different runners with different speed in Zeno’s Paradox while the items in Harmonic Series corresponds to those steps of the tortoise in Zeno’s Paradox. So, not matter what kind of runner (even a runner with the speed of modern jet plane) held the race with the tortoise he will never catch up with it.
Lacking the systematic cognition to “infinitesimal”, no one in the world now can answer following question scientifically and this is the very reason for many “suspended infinite related paradox families” in present classical infinite related mathematics:
Are “dx--->0 infinitesimal” in calculus and “Un--->0 infinitesimal” in Harmonic Series the same things? If ”yes”, why we have totally different operations on them? If ”no”, what are the differences and how to treat them differently and why?
--------Could anyone tells how many items of “Un--->0 infinitesimal” in Harmonic Series you use to produce the first Un’ >10000000000000000000000000, how many items of “Un--->0 infinitesimal” in Harmonic Series you use to produce the second Un’ >10000000000000000000000000, how many items of “Un--->0 infinitesimal” in Harmonic Series you use to produce the third Un’ >10000000000000000000000000?