Monday, 18 March 2013

petty townhouse rules

It has recently occurred to me that most townhouse complexes in affluent areas (not to mention blocks of flats), have bylaws prohibiting inhabitants/residents from drying their laundry "on display" in the sun.

It has also occurred to me that this forces residents to use tumble-dryers, which both damage clothes after repeated use (implying costs to households), and which use enormous amounts of electricity (2000 watts per hour, or 2 units of electricity per hour), also implying costs to households, environmental costs, Eskom load problems.

If one considers that South Africa, as a sunny nation, has the benefit of allowing one to dry laundry in the sun, and yet these bylaws prohibit it, it may be worth considering the environmental impact, and the impact on Eskom's ability to deliver power, of this prohibition. It is my view that the relevant bylaws should be scrapped, and that sun-drying of laundry should be encouraged.

Let's work a quick calculation to see what I mean.

Suppose the affluent population of SA is about 10 million people. Suppose, furthermore, that of that 10million, there are four persons per household (I got this figure from Wikipedia). That means 2.5 million households, roughly, with tumble-dryers. Now, let's calculate the power wasted: 2 units per hour. Let's assume, furthermore, that an average household runs four loads of washing per week, ie four hour sessions of tumbling, or 16 hours per month. At two units per hour, that's 32 units of power per household per month. Assuming again 2.5 million tumbledryers, you're looking at 80 million units of power, or 80 MW wasted per month. Eskom can only produce 34 000 MW. Granted, this is only 0.23 % of Eskom's capacity, but it's still something. Have I made a mistake in this rough calculation? Is this something to be concerned about?

Thursday, 14 March 2013

open letter to Apple for Mar 2013


I was thinking the other day that power plugs, USB plugs, etc., are a bit of a nuisance when we have things like RFID, bluetooth, wifi, and induction etc., available. Then I was thinking about my electric toothbrush, which doesn't make metal-to-metal contact with its charger; instead, the charger that it sits in is a proximity induction type (ie moving magnet near a wire creates a current).
So I was thinking it might be cool to remove the metal contacts on the charger cable for MacBooks and replace it with a sealed plastic plug, that just induces the charging current in the MacBook. This is good for a number of reasons, not the least of which is that my toddler won't get a shock from sucking the power cable anymore!
Plus, if you get rid of USB ports, etc., you could potentially eventually make a waterproof iPad that I can use to read in the bath, which is what I miss most about paper books.
Here's a sample of something already using this idea:
Thanks for listening.

Wednesday, 13 March 2013

installing apache, php, mysql on Mac OS X 10.8

php 7 nightmare

OK so Centos 6 insists on installing php 5.3 and even if you download other RPMs and install them, they do not replace the existing 5.3 whic...