[Avodah] zilzul shabbat

[Eli Turkel via Avodah]

REMT wrote
> True; but not putting a light on or off *has* been a defining feature
> of the Shabbos experience since the mitzva of Shabbos was given, so
> accomplishing it by any means might properly be considered a zilzul
> Shabbos.  (Of course, by this argument, putting an electric light on or off
> should be prohibited even if the use of electricity is not a m'lacha.)

In particular using an preset switch to turn lights and off should
be prohibited.
While RMF originally did object he later changed his mind when it became
the norm.
In fact even the kosher lamp might be prohibited



Can someone come up with a definition of zilzul shabbat?
Is every modern way of doing any melacha that does not technically
violate hilchot shabbat zilzul?

The gemara allows using the sun for cooking on shabbat - why isn't that
zilzul shabbat?

-- 
Eli Turkel