John Graham-Cumming: The greatest machine that never was

Computer science began in the ’30s … the 1830s. John Graham-Cumming tells the story of Charles Babbage’s mechanical, steam-powered “analytical engine” and how Ada Lovelace, mathematician and daughter of Lord Byron, saw beyond its simple computational abilities to imagine the future of computers.


Alan Turing: “It doesn’t matter how you make a computer”. A computer can be mechanical, electronic, or even built on cells.



Mental calculation hacks and estimation for engineers

As I was reading the chapter on math from Mind Performance Hacks, I realized that I have already been using some mental calculation hacks mentioned in the book without knowing they are actually hacks. (This is one of the amazing things reading this book,   understanding more about my own mind.) Some hacks that I’ve been using, also mentioned in the book –


If I want to add a list of numbers, I would first rearrange them to make 10s or 5s, then add them up in tens. This is especially useful for checking bills.

eg 24+25+33+12+16 = (24+16) + (33+12) + 29 = 40 + 45 + 25 = 110

Looking for friendly numbers

Work with numbers you are more comfortable with. Instead of multiplying 29 to 7, multiply 30 to 7 and subtract 7 from the result.

Working opposite

Multiplying is always easier than dividing for me. So if I need to divide 102 by 7, I would keep multiplying 7 by a number until it exceeds 102 (find out the number of sevens in 102).  Stop at 7×15 (105) because that exceeds 102, so there are 14 sevens (98) in 102 with a remainder of 4.

Some hacks are particularly interesting, especially the part on estimation which is so useful for engineers.

Estimate orders of magnitude [Hack #41] – I like the part on “How would you move Mount Fuji”. This reminds me of what my physics professor liked to do during lecture, he used such technique to solve really weird questions like how many water molecules in a glass of water we drink were also drank by Einstein.

As an engineering student, I love the magical sign . Approximation is so useful for calculations in engineering, especially when designing circuits and devices. We often make a lot of estimations, because unlike maths, there isn’t really a “correct” answer (or we couldn’t be bothered), anything less than around 10% error is considered good. In reality every component has a tolerance, normally it’s 10% or 5% tolerance, but even with the same tolerance different manufacturers also vary a lot, components don’t come at their rated values. Surely you can get everything with very low tolerance, but what are the cost? Engineers also worry about money, a lot! I learnt this because every time when I can’t think of anything for those pros and cons questions, I would just write “expansive” under cons or “low cost” under pros, I would definitely get something (another hack maybe?).

I was so happy when I was learning to design circuits (on paper, it was a university course) because I could finally calculate using a lot of nice looking whole numbers and not press the calculator until my fingers cramp (A level math and physics, yuck!). I remember one of my professors said that in engineering everything is based on assumptions and approximations. There is always an “ideal something” and then a “real something”. Just like my grades, I make a lot of assumptions when calculating my ideal grades, which are just estimations of my REAL grades, very bad estimations… :(

Secrets of a High Performer

I registered for a workshop without hoping to get much out of it. It’s the kind of event that nobody would care to go if not for the 1.5 hours course credit for a useless but compulsory 0-credit course. The instructor also mentioned this at the beginning of the workshop, which ironically was a very good starter to get everybody’s interest and a few laughs.

Surprisingly this workshop turned out to be quite motivational, I actually gained something out of it. The instructor talked about how to be a high performer in study and later on in career as well as in life. Especially now at this point in life I am feeling kind of lost and disappointed, so I find these tips really useful for me to regain some direction in life.

Set specific and achievable goal/dream

Like it or not there are certain things that are just not meant for you no matter how much you want to get them. So instead of sulking and getting more disappointed when you fail, why not just find some other goal or dream that you can achieve?

List potential values for accomplishing your goals

What motivates you to accomplish your goals? It can be tangible rewards (money!), personal attainment (higher status/degree) or interest and passion. Of course passion is very important, like every successful person would tell you to do it for passion and not for the money or fame. But hey, let’s face it, even if you think you are doing your dream job or degree, there is always some part of it that you hate to do but can’t escape. It’s very easy to get fixated on your dreads and lose the passion you started with. So having some extra rewards that motivate you is also good to keep up your passion.

Analyse the situation, set realistic action plan stick to it

Just believing that you can succeed is not enough, make systematic and realistic action plan on how to achieve your goals. More importantly, ADJUST your plan if it’s not working well.

Find meaning in what you do

Apparently people who know exactly what they want and why they do something (can be anything, money, fame or passion), and act consistently are happier. To think of it, quite often I would come to a frustrated point where I ask myself why am I doing this, and frankly speaking, many of the things I did turned out to be utterly meaningless. But then I read about the philosophy of Albert Camus and the Myth of Sisyphus, it is only when we identify that life is meaningless and ACCEPT it, could we begin to live. In a way the realization that life is meaningless is also in itself finding a meaning, as opposed to not knowing why. I like Camus’ last line in the Myth of Sisyphus – “One must imagine Sisyphus happy”. (This is not from the workshop, only my own interpretation.)

Pause and reflect, or simply take a break.

This is so true for busy Hong Kong people. They are definitely on the top list for walking the fastest on streets.

Be grateful and have a positive mind

This is a personal one, definitely also my most important take away from the class. Appreciate the little things in life. Nobody likes to be around a person who is always complaining. Replace negative thoughts with positive ones.

Identify with peers and explore new relationships

Research has shown that peers are the most influential than any other groups, and peer learning is the most effective type of learning especially in university. So… ho professors! Please talk less so that we could study better!

Mind Performance Hacks – Memory

I’m reading Mind Performance Hacks from the O’Reilly Hacks Series. I just finished the first part about Memory, there’s a number-shape system thing I find pretty interesting. Apparently there are a whole lot of ways to remember NUMBERS, and you can use those memory tricks to remember pretty much everything in your life.

I remember watching a TED talk by Daniel Tammot, who explained how he perceives numbers as different shapes and colors. He has a condition called synesthesia, it’s not something he learnt. People with synesthesia have their senses mixed up, so they could perceive number 5 as salty or an apple as loud for example. And of course Daniel Tammot broke the record of the compulsory test for memory experts – reciting pi (everybody’s favorite pi, I could remember… let me see… 8 digits!)

Unfortunately people like me don’t have synesthesia, but I just learnt a new hack to associate numbers with shapes, [hack #2] from the book. Basically it goes like this – for every digit (0-9), come up with a shape that resembles it, so you can use that shape to remember the number. There is a list given in the book, I came up with my own list (not very different) that’s easier for me to remember.

0 – hole

1 – sword

2 – swan

3 – heart

4 – flag

5 – hook

6 – little wormly guy

7 – axe

8 – woman’s hourglass figure

9 – tadpole

Now if you want to remember a list of things or points to speak in a meeting, imagine a scenario or story using the shapes associated with the numbers. So this is what I want to buy today at the supermart

1. Snacks
A sword slashing snacks raining from the sky (fruit ninja style)

2. Beer
A drunk swan swimming in a lake of beer

Pretty absurd, but according to the book the more absurd or surreal (even offensive) your story is the better you can remember it. “Strong emotional reactions help people remember things”.

There are many other ways the book mentions, like associating numbers with sounds, letters, places etc. But I find most of them are too difficult to remember (I might as well remember the numbers themselves).

Honestly I haven’t tried using this method to remember anything, I don’t know whether it works for me. It takes some practice to get used to it. But memory block is one of my main problems when it comes to exams, I really need to find a good memory hack. Yea, can’t escape from memorizing heaps of information and formulae for EVERY exam even in university. No matter how the professors swear that they are not testing you on memory, seriously, don’t believe them! They only say that because they can’t remember anything themselves. We are still not allowed to bring wikipedia or google to exam halls, aren’t we? So yes, we are still being tested on MEMORY and we better be good at it!

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