pen it down

It's sometimes a mystery to me why there are so many problems I can ponder in my head that seem as unsurmountable conundrums, only to seem quite simple to resolve once I write them down(or more likely type them out). According to the extended Church-Turing hypothesis, all computable problems can be solved with a Turing machine. And a human brain is surely Turing complete, right? It can simulate a Turing machine by following the procedure step by step. But aha! The assumption of an infinite memory tape is not held! A normal human brain that doesn't write anything down can't store and retrieve arbitrarily long bit strings at will. So an unassisted human brain is not Turing complete. But armed with a recording device - aha! Then the human is Turing complete, and can solve all kinds of (computable) problems. So I guess when people argue that writing is the greatest human invention, I could supply another (not particularly intuitive) reason to support that argument.

double happiness!

I'm really happy for my sister. Both my sister and her now-husband are so amazing! I'm glad that things are moving ahead in their lives. I'm also glad that I can now refer to the amazingly intelligent, considerate and decisive (and lucky) Oliver Wicker as my brother-in-law instead of "just" my sister's boyfriend(which has a somewhat transient feel to it, even though they've been together for so long!). And I can refer to Kitty as "my sister-in-law... sort of" instead of the awkward "my sister's boyfriend's sister" which somehow seems more distant than it feels. During the wedding reception(which was a high tea), I had the chance to sit with and talk to people around 9 years older than me. It's quite remarkable how... "steady" (forgive my diction) they seem! Conversation flows easily and casually even between strangers - they know what questions to ask to simulate a friendly chat, and how to respond in a witty manner. I wonder if it's because they are in the same age group and they have a better idea of what the concerns of people of that age are? Or perhaps making friendly conversation with people they've just met is a universal skill they've acquired over time? That seems like a really useful thing to learn. Sitting at that table I keep feeling that they know a great deal about life that I don't, but they are all pretty cautious about giving advice. For a while after the reception I felt like I was the most immature of the bunch of people at the reception (well maybe excepting the one year olds), and wondered: Do all x year-olds talk like x year-olds? I don't want to be sound young and immature! Is there any way around it? And my mom told me: It can only come with experience, through success, failure, or even suffering, and all that will take time. Of two people of the same age, one can sound like old when talking about one thing, but he'll probably sound younger when talking about another, as the time they have will tend to equalize the amount of experience they have, and no experience has greater intrinsic worth over another, be it success or failure. Oh well, I guess I can only wait then!

Brought about by change

I just identified the background music in NLB when they announce "Dear readers, the library will be closing in 15 mins, …) it's moonlight sonata! -------------------------------- Today, when I received some change from a waitress, I was reminded of this story by my primary school teacher: there was once a student who didn't really know etiquette. So everyday, when the student submitted a notebook containing his homework to his teacher, the teacher would toss it aside and walk away without any explanation. This made the student frustrated yet puzzled. Every day he would greet the teacher, or say something nice before submitting his homework, but the teacher did the same thing: toss it aside, and walk away. It was only one day when he finally, by chance, decided to try handing in his homework with both hands that the teacher finally accepted it. So, according to my teacher, the moral of the story is: it's more polite to hand things over with both hands. But the obvious thing in the mind of the student would be: Why doesn't the teacher just tell me what I'm doing wrong? Perhaps, the student could also have watched how other students were handing in their homework to try to figure out what he was doing wrongly. That reminds me of an article about reinforcement learning vs imitation vs instruction. The article found reinforcement learning to be less effective than both imitation and instruction for a certain task. It makes me wonder: if machines become conscious, would they get frustrated when we try to train them to do something by reinforcement learning? Would they think, "Yeh right, as if you know how to do it!" or "Why don't you just tell me what you want and not make me do this over and over again?" But I guess there will always be some amount of reinforcement learning to be done as long as there are unsolved problems - some people need to stay at the forefront to do less inefficient learning task of discovering new methods, while others can help to spread the knowledge in a more efficient way by making more people aware of the method, or by teaching it well. Perhaps the moral of the story is that Nature is kinda like that annoying teacher in that story, and we as students should help to make each others' lives a bit easier.