[Avodah] Explaining boneh/electricity to a non-religious person

[Zev Sero]

rabbirichwolpoe at gmail.com wrote:

> This might explain why during crises [think 9/11] many frum Jews
> left their radios on all shabbos which lich'ora is a hashma'os kol
> problem.

Please explain what you mean here by "hashma'os kol problem".  I'm
aware of two unrelated issues on shabbos that can be called "hashmoas
kol":

1. The prohibition on using a noise-making device.  A radio is surely
not included in that prohibition, since one doesn't use it to make
noise - one simply turns it on and it makes noise on its own.  Kal
vachomer leaving it on before shabbos can't be included.

2. The prohibition on having ones mill running on shabbos, or any
similar machine that makes noise heard by passersby, who will think
that one is breaking shabbos.  This doesn't apply if there are no
Jews within a techum shabbos.  It also would seem not to apply to
any machine that is not audible from outside ones property, such as
a radio.  And it surely wouldn't apply if a Jewish passerby's first
thought would be that it was on from before shabbos, or was on a timer
(e.g. a clock radio in the morning). 

Did you mean one of these two issues, or something else?

-- 
Zev Sero                      The trouble with socialism is that you
zev at sero.name                 eventually run out of other people’s money
                                                     - Margaret Thatcher