Sunday, 21 January 2018

Just discovered Nassim Nicholas Taleb

"One should never do anything without skin in the game. If you give advice, you need to be exposed to losses from it."

Interesting stuff.

In short, averages do not represent probabilities - rather bet on the two extreme ends to deal with the possibilities of worst-case scenarios.

Saturday, 20 January 2018

Apple Mail doesn't open attachments on double-click

If your copy of Apple Mail since macos 10.11 doesn’t open attachments with double-click, do this


1. Open Terminal

2. Type

mv  ~/Library/Containers/  ~/Desktop ; sudo reboot

you can just copy/paste this.

3. Type your password (it won’t display), and press enter

Solution credit: Linc Davis, here:

Monday, 25 December 2017

random thoughts on cryptocurrency future

We saw huge profit-taking at Christmas which drove the currency down across all cryptocurrency coins by about 25%. I think this was just profit-taking and not a sudden lack of faith in the market.

However, we’re definitely seeing weaknesses in btc at the moment. Slow response times - over a day - and very high fees - I’ve seen up to about $30. It’s unacceptable and unusable.

Ask yourself the following questions.

1. Is the future of currency digital?
2. Is bitcoin technologically sound? (will it be ok as-is for the future or will it have to be hacked to a new better version)

If you said yes/no, (as I do), then you should stay in cryptos but divest of btc itself.

If you said no/no (as skeptics do), then sell all and get out.

If you said yes/yes, then hold and see whether btc survives.

[obviously: If you said no/yes, then you’re confused, or don’t know what bitcoin is].

My suspicion is btc will survive as a reference currency - like the USD in fiat markets - but that it has a limited use case because of technical problems.

5.5 billion people competing for 16 million coins mean that each coin is split so that each adult gets 0.003 btc. Meaning that if we take it that 0.003 btc is equivalent to say a month's wages, and the average wage is say 1000 usd, it means that the target price for btc is 0.003 = 1000 usd. Or $ 343 000 per btc. Just a guess. It's looking pretty bad right now.

Wednesday, 13 December 2017

List of useful mac apps

This is mostly a note to self so that I can share with others when they ask which apps I recommend.

Android File (*) get files off android device
Android (*) make android apps

audio (*) music deck (*) scrobbler (music recommendations) (*) scrobbler
Sound (*) editing sound files
To MP3 Converter (*) convert funny audio files to mp3

Bartender (*) get all the mini icons in the menu bar under a menu
Battery Health (*) show battery status

BTC (*) show current cryptocurrency values in menubar (*) best wallet app

Cleaner for (*) clean memory caches to improve performance for new files (*) keep clipboard history and strip font/formatting from copy/paste (*) best ftp client
Default Folder (*) force open/save dialogs to place you somewhere intelligent, e.g. the folder the file came from!

A Better Finder Rename (*) bulk file renames, e.g. to strip spaces or other funnies
Bitdefender Virus (*) mostly for PC viruses to help PC users out
Carbon Copy (*) best backup app, makes a bootable full copy.
CleanMyDrive (*) looks for garbage (*) best compression tool
StuffIt Archive (*) to open files from the above, listing files first
StuffIt (*) to just expand files from the above without ceremonies

NEVER INSTALL : mackeeper. It’s malware.

DjVu (*) to open DJVU files (like PDF) (*) to create document indexes for PDF (*) epub viewer and store, canadian
iBooks Creator (*) from Apple, try it.
Font (*) great app to convert OTF/TTF/PS fonts into other formats

graphics (*) batch resize or watermark images (*) similar to corel draw / adobe illustrator - very good (*) - similar to photoshop, much cheaper, very good


Pst Easy (*) - convert Outlook PST files to Apple mail files (*) screen sharing
Little Snitch (*) stop spyware from accessing websites - you approve/deny all interactions with internet. Basically lets you build a firewall on the fly. (*) far prefer to excel as it remembers stuff like copy/paste (*) far prefer to Word as it lets you create a spreadsheet inside a wordprocessing document. (*) tool to manage academic research papers

Combine (*) to tack JPGs and PDFs together into single documents, or split them into single pages
PDF OCR X Enterprise (*) convert bitmap PDFs to text-readable pdfs
PDF to
PDF to Word - Convert PDF to Microsoft
PDFKey (*) to remove passwords on PDFs (you still have to enter the password, but once you’ve entered it, it removes it)

+ PDF to (*) blogging app - saves you the bad interface of blog sites.
MindNode (*) mindmapper
MyPoint (*) to control PowerPoint from your phone
StakePoint (*) PM app

programming and maths
Daum Equation (*) to create math equations
MathMagic (*) ditto
QR (*) to make QR codes (*) to check the SEO-goodness of your website
XML Site (*) to create an XML map for google search

Project Management and similar
Flowchart Designer (*) mind mapper (*) PM app
Project Viewer (*) to open MS Project files (*) to control CPU fan speed (*) twitter client (*) find and delete duplicate images in bulk, keeping highest quality ones

Video (*) convert any video to any other video
Air Video (*) play streaming video from your mac to your ipad
AVI to Any (*) convert AVI (*) rotate a video (e.g. if you film with your phone sideways) (*) to play FLV files
MKV to Any (*) convert MKV files
MP4 to Any (*) convert MP4 files
To M4A Converter
WMA to Any
Wondershare Video Converter
Xilisoft Video Joiner (*) to join video clips easily and quickly
Xilisoft Video Splitter (*) to split...

Thursday, 16 November 2017

some crypto currency news and readings

Apologies for the link farm type of article, this is mostly to share with people interested with latest interesting stuff.

Academic certificates in blockchain:


Programming contracts in Ether:

Hedging cryptos:

Mastercard supports blockchain:



Why bitcoin stopped responding last weekend:

Amex supports XRP:

More scams, mostly because of last weekend:

POS software:

Tuesday, 7 November 2017

Correct English


Please note this page contains the author's opinions only and may differ from the Rules and Regulations of the University. Please consult the University Rules, which overrule these.

Nice page:

On this page I list common errors people make in their usage of English, and provide the corrections. You'll notice that I can't make up my mind whether English is capitalised or not. I have the same problem with "earth." Anyone want to correct me?

PS If you don't think learning to spell is important, please consider the below:


Apostrophe, possessive and plural forms. This is used to indicate a missing letter which was historically present. Hence, the word "don't" contains an apostrophe because it is a contraction of "do not." the apostrophe replaces the O. Other examples are "let's", which is short for "let us", and "he's", which is short for "he has" or "he is". E.g., "He's got a car" means "he has got a car". Similarly, in the past, i.e., about 1000 years ago, English used -as for plural and -es for possessive (genitive). Since the loss of the vowel in these suffixes, we now use the apostrophe to denote the E in -es (genitive). e.g., John's apple's red colour—meaning, the red colour of the apple of John. If John has more than one apple, it would be apples (without an apostrophe) to indicate the presence of more than one apple, however, if we still want to talk about the red colour of John's apples, we have to add an apostrophe to indicate that we're not putting the -es of possessive form, but we know it should be there. So it would be: John's apples' red colour. American usage retains the second S, i.e., John's apples's red colour.

Why you should hodl (hold) before a fork

The trouble with buying additional bitcoin just before a fork is that the price inflations will counteract the value of the new coin.


Look at the previous case. BCH (bitcoin cash) came out as about $300-400 after the first fork in July. That was about 10% the value of the btc.


So if you panic-buy before a fork, you should not buy more than 10% of what you hold.


For example if you buy 0.1 btc now, it will cost R 10 000, or about $ 700. But after the fork, the value might collapse all the way back to $4500 or so. Meaning you lose about R 5500 / $ 400 value.


However, assuming 0.1 of the new coin is worth 0.1 of $ 300, you’ll make $30 from the new coins. $30 doesn’t compensate for the post-fork losses of R 5500 / $400.


In other words, when a fork comes up, hold or sell. (You can buy back when the market hysteria dies down at a lower cost).

Here’s an example of a fast buy/sell cycle.

Suppose you buy 1 BTC at $ 4000 at time X

Suppose a fork comes up and the price of 1 BTC goes to $ 7000 (like it just did), at time Y, just before the fork

The value increase is $ 3000.

Now, if you sell 1 BTC, you gain $ 3000 on your initial investment of 1 BTC.

Suppose after the fork, the price crashes down to $ 5000 - not as low as you originally bought at, but lower than the pre-fork hysteria price of $ 7000.

You wait for the crash to finish and the price to stabilise, and buy back at $ 5000.

You still have $ 2000 in the bank that you can keep or use to buy additional BTC.

If you decide to take your $ 2000 profit into BTC, you can get 0.4 BTC.

That means by selling just before a fork, you can come out at 1.4 BTC instead of 1 BTC with no actual material losses.

At the next fork, your 1.4 BTC won’t be a mere $ 7000, assuming the hysteria carries 1 BTC to $ 7000 again. Your 1.4 BTC will then be $ 9800.

Sell just before the fork, wait for the post-fork crash, and buy back at a lower price.

Rinse and repeat.


Just discovered Nassim Nicholas Taleb

" One should never do anything without skin in the game. If you give advice, you need to be exposed to losses from it." https://e...