There’s a mystery that I just cannot get my head around. What exactly is mathematics? Some would say it is a language. Yes, I would agree with that, but there’s more to it than that. My problem stems from my passion for quantum physics and the mysteries of the universe. You may or may not know that in Einstein’s time there were two principal branches of physics, the big picture that Einstein so eloquently described (it dealt with the sky at night, gravity, time, mass and energy) and the small picture, generally known as quantum physics (which deals with elementary…
General Interest
I had to go to the SARS Tax Practitioners’ Unit in Pretoria, then on to the Import Export Unit downtown Pretoria. The parking at Tax Practitioners is great, but downtown, it is positively dangerous and you can only find illegal parking “protected” by self appointed car guards. I’ve always had to take a chance, but when I mentioned it to Helen, she suggested I leave my car at Tax Practiitioners and Uber to Import Export, do my business, then Uber back to my car. Now why didn’t I think of that?
Is it my imagination or are the roads around Johannesburg getting fixed? I live in Fourways and work in Midrand. The first thing I noticed was that potholes were getting repaired, but it has gone beyond that, roads are being resurfaced all over the place and in many cases widened. I wonder whether Pretoria and Nelson Mandela Bay are getting the same treatment? Where is the money coming from? You don’t have to be a rocket scientist to figure out that the DA and other opposition parties are plugging the corruption leaks in the municipalities that they have taken over.…
Do you play cribbage? It is the best card game for two by far, or doesn’t anyone have time for card games any more? Here’s how we spiced the game up even more with jokers. Helen and I play about twice a week, usually when we’re taking something from the freezer that Helen cooked previously, or when I’ve brought in shushi from the local Japanese place. A game of cribbage has all of the elements essential to any good game – luck, skill and some really close finishes. We added an interesting variation, which worked out well. If you know…
We all have times when there are just a stack of jobs to do and we have to decide which ones we’re going to tackle first. A knowledge of queueing theory can help us decide. Suppose you have 5 jobs in the queue and each one will take a different amount of time – Job 1 – 7 hours; Job 2 – 3 hours; Job 3 – 5 hours; Job 4 – 1 hour; Job 5 – 12 hours If you do the longest job first, then the next longest and so on, doing the shortest job last, then the…
We needed to paint the garden wall and I had to break up the old trellis to separate it from the creepers which had intertwined with it. We were quoted about R15 000 for replacement trellisses and I figured I could do better. Here’s how – This is what I set out to achieve – D’you see the almost invisible trellis? First I pinned the wall 60cm apart horizontally and 40cm vertically Notice that this one is on a curved wall which solved another problem. Then, using 1.5mm braided stainless steel wire and electrical crimp unions I fitted the wire…
Can you fit a square peg in a round hole so that no light shines through? No. But you can fit a round peg in a square hole. Here’s how. Lets say the hole is 2cm by 2cm square. You need a round peg (or dowel) 2cm diameter. Cut it 2cm long. Turn it sideways and slip it into the hole. Perfect!
So you don’t believe in telepathy. Well, try this on for size. On Friday evening, my wife and I got to talking about our childhood (we don’t have television) and she couldn’t believe that I had never had a teddy bear. I was pretty sure that I hadn’t, but phoned my sister in the UK to confirm. She didn’t answer the call, but called me back the following morning. I jokingly told her why I had called her the previous evening. She confirmed that neither of us had a teddy bear when we were young, but that the reason she…
As you know I am a CA(SA) a Pr(Eng) and a member of Mensa (the society for the super intelligent). So I have to share with you what a total idiot I am as well. We have horizontal blinds in our house and the lifting chords on one of them wore out. My wife took it to be re-strung and I collected it all beautifuuly wrapped in bubble pack and adhesive tape. I stood the package on end, took my Stanley knife and cut the bubble pack from top to bottom. When we re-hung the blind we saw that I…
Some time back I posted an article on the fantastic power saving you achieve by switching your downlighters to 12v LEDs. Now I have one work of advice – DON’T I recently added eight new downlighters to my wife’s sewing room. For this I had to buy 8 electronic transformers (they’re actually drop down 220v AC to 12v DC converters) whereas when I converted the house to LEDs I simply used the old transformers (which are no longer available). I spent one and a half days fitting the new downlighters and when I finally switched on, most of them started…
Why do we have so many beggars in Johannesburg? Why do we have so many street vendors selling counterfeit goods at our robots? Now if you were thinking of going into the begging business you would surely start off with a belief – “People give to beggars”. If they didn’t you wouldn’t go into the business would you? Same with counterfeit goods – “People buy cheap versions fo the real thing”. If they didn’t you wouldn’t go into the business would you? How about stolen goods? – “There’s always a market for stolen goods”. If there wasn’t, people wouldn’t steal…
We just installed a petrol generator from Adendorff Machinery Mart (to replace the diesel brute that my neighbour complained about). Now we only have 5Kw to play with instead of 25, so I drew up a chart of what can be on at any one time. It proves possible that we can still survive an extended power outage and we don’t switch off our fridge or two freezers. However, the geyser pretty much has to run entirely on its own except for lights and computers. We had to engage an electrician to make sure that everything that we wanted on…
My lovely wife, Helen, is passionate about sewing. This means that just about all the available storage space in the house is taken up by fabric and with the fabric comes thread (at least four reels of each colour). Reels are not an easy thing to store so they have ended up rattling around in drawers, so here’s what I did – That’s storage for about 3 000 reels! Now that meant that I had to drill about 3 000 blind holes properly spaced and of equal depth and I also had to cut 3 000 dowels, all exactly the…
I wonder about synchronicity, telepathy and coincidence. So very often I will, for come reason, be thinking of someone who has been out of my mind and my circle of activity for months or even years. Typically this would be in the early morning while I’m preparing to leave for the office. I’ll get to work and sometime in the morning that person will phone me. I believe that this happens too often to be coincidence. So if not coincidence, what is it? Some people will call it synchronicity. So what is synchronicity? It’s a term first introduced by Carl…
I’ve just replaced all of our downlighter globes with LEDs. There are about 50 of them, so at 4W each, that’s power consumption equivalent to two 100W globes. But there are a couple of catches that you should be aware of. Let’s look at the other plusses first. 1) They don’t get hot so the downlighter fittings will last much longer. 2) The transformers don’t get hot because the power is so low, so they’ll last much longer. 3) The fire risk drops dramatically for the same reason. Now the downsides. 1) You need to make a call – Cool…
How often we hear on the radio “Crime in the last year cost the country X billion rands” or “Nkandla cost the country R210 million rands” or “Something else cost the country Rxxxxx” Really? What do we mean when we say “Cost the country”? Money circulates through the economy of South Africa. I buy an ice cream, the ice cream business buys whatever goes into an ice cream, pays for electricity, factory premises, salaries etc. One of the ice cream maker’s employees spends part of her salary on a new dress, the dressmaker makes a profit, a criminal steals the…
Well, not stolen exactly. Borrowed? Some of them are my own, so you can have them in exchange. All of them have become so much a part of my everyday life (well, except one, number 10) that I’ve almost forgotten what a jump forward it was when I discovered them. 1) You can share an Excel workbook, but the problem is, every so often it updates itself with the changes made by the users and then you all have to wait while it is doing so. Also there are conflicts that build up between updates and they have to be…
We wanted to do something special with this odd space by our front door at home We asked Chris Bowden of Green Solutions Landscaping http://www.gsolutions.co.za/ if he could come up with any ideas for a distinctive water feature. This is what he built for us Now, not only did he read our needs perfectly, the entire job was performed with care, skill and passion. Well done Chris. . Should you wish to make an appointment, please feel free to visit Derek’s diary and book a time that suits you.
This is for those of you who are in some way learning to speak French. There are two tricks. One will enable you to know the gender of a noun without having to remember it (is it le thingy or la thingy?) and the other will get you speaking fluent bad French in no time flat. French was a compulsory subject at my school and they did their best to teach us all. I hated it and yes, I failed it at ‘O’ level. Many years later, when I was in my mid 30’s, I had to spend two weeks…
I was busy writing a Trust Deed and I got to the bit where I say “if there is less than five trustees then ….” and then I stopped. Should I say “if there are less than five trustees then….” My lovely wife agreed with my first choice – one would say “there are five” but “there is less than five”. I phoned my “linguist” daughter Claire Williams in Durban (she writes copy for Thompsons Travel). She was confident that I should say “there are less than five trustees then ….” so I asked her what should I say if…