<<I also don't know of the CI would prohibit closing a circuit that doesn't do anything>><br>If closing a circuit that doesn't do anything is assur then touching any two pieces of metal or wire is also assur as those two cases are identical in my mind.<br>
<br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">This is actually a machloket of later poskim interpreting the CI. i.e.<br>
can one plug in<br>
an appliance (according to CI) while the shabbat clock is off and then<br>
use it aqfter the<br>
preset shabbat clock goes on.<br>
When one plugged in the appliance nothing happened because there was<br>
no electricity<br>
and so there is nothing "live". However, if one considers it as<br>
closing a circuit is would<br>
still be prohibited since one closed a usable circuit even though<br>
currently there is no<br>
electricity.<br>
I think that this point point was even raised by RSZA according to the CI.</blockquote><div>This doesn't seem valid to me. When the timer is off and the appliance isn't plugged in, you just have a circuit that is broken in two places. once you plug in the appliance, until the timer ticks (if it is a mechanical timer for sure and even an electrical timer probably) the circuit remains broken and should not be considered boneh. <br>
</div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><br>
<br>
Similarly CI doesnt make any differentiation between actively closing<br>
the circuit and<br>
removing a resistor that allows electricity to flow through an existing circuit.<br></blockquote></div>This seems to me to be more analogous to the water flow case. The current already has a path to flow and you are just adding or removing resistance to it. (A practical example of this is a dimmer switch (on a non-incandescent bulb to avoid any bishul issues).) Is there any reason why this could be considered boneh?<br>