To complete the thread about a maximum force value in nature, here are some
interesting points.

In the German newsgroup de.sci.physik the discussion has has made many waves.
The claim that c^4/4G is the highest force in nature has lead to a search
for counter-examples, but no counter-example was found to be realistic (IMHO).
However, a professor with relativity as his research topic is not convinced yet,
and the exchange is going on. On the other hand, he has not yet
given a counter-example.

The claim of a maximum force in nature is made by Schiller (physics/0309118)
and by Gibbons (hep-th/0210109) . Interestingly, Schiller also claims a
maximum POWER value in nature, given by c^5/4G (from Pmax=vmax Fmax).

A maximum power is also a maximum luminosity.
Also this value, he claims, is never surpassed in nature, neither by the
whole universe, nor by quasars, gravitational wave sources, mini black holes,
etc. He made this claim already in his textbook some time ago.

This limit might be even simpler to beat, with a suitable counter-example.
However, I have not been able to find one. (The German newsgroup now
offers 40 Euros for the first counter-example. I hope this does not count as
a commercial post. :-)

A maximum power means that engine output is limited. In simple words,
there is a maximum number of horse-powers possible in nature.
Is that true?

Tom Helmond