If P, then Q. P. Therefore, Q.
If P, then Q. Not Q. Therefore, not P.
~Detecting Cheaters by Bruce Schneier
Detecting Cheaters has been on my "to read" list for quite some time now, but only got around to reading it a few days ago. I found it quite interesting, so going to give a rehash of it
Some of you may recognise the above as a 'logic statement', and to some extent it is fairly obvious. Associating the above with a concrete example may make things easier to understand.
If you forgot your keys, then you need to call the locksmith.
So in the example above, P='forgot your keys', and Q='call the locksmith'. Does that all makes sense so far? Let me introduce what is known as the Wason selection task. The concept behind this task is quite simple - you are shown four cards, each containing some form of information on each side (eg. one side will be about forgetting/remembering your keys, the other about the locksmith). The cards are placed so you see (face-up):
(a) Forgot keys
(b) Remembered keys
(c) Need to call locksmith
(d) Don't need to call locksmith
Your task is simple, determine which two cards you need to flip in order to confirm that the "If you forgot your keys, then you need to call the locksmith" statement is true. So, which did you choose, (a) and (c)? If you did, then you're wrong, but don't worry, you're not alone. (a) is correct. You need to check that if you forgot your keys, the other side of the card says "need to call locksmith". However, (c) is incorrect. The above statement puts no restriction on "you needed to call a locksmith, because of something", 'something' can technically be anything and the above statement still holds true. The correct answer is (a) and (d). In order to confirm the above logic statement, you need to make sure (a) is true, and (d) is true. (a) as aforementioned, and (d) because you need to check, if you didn't need to call the locksmith, then you didn't forget your keys; if the flip side of that card had 'forgot your keys' then it goes against the "If P, then Q" statement. In other words:
You forgot your keys. Therefore, you need to call the locksmith.
You don't need to call the locksmith. Therefore, you didn't forget your keys
Confused? Let's try again...
If you ate dessert, then you ate your vegetables.
So, how do you confirm this statement? How do you make sure that if your little sister is eating that delicious chocolate tiramisu, she ate her brocoli? Again you have four cards to choose from (I'll mix up the options a bit, and don't cheat by comparing with the above!):
(a) Ate dessert
(b) Ate vegetables
(c) Didn't eat dessert
(d) Didn't eat vegetables
Which two would you choose? If you were like me when I first read Schneier's post the answer might've just 'lept' out at you, (a) and (d). You want to make sure if your sister (a) ate dessert, she really did eat her vegetables; and that if she (d) didn't eat her vegetables she shouldn't be eating dessert! Now, did you get that right? or at least was that easier to understand?
If I explained things properly, then you really should've found the latter example much easier to digest. The reason appears to stem from the fact that the latter example is related to cheating. We seem to be more adept at figuring out if someone 'cheated', for example, if they ate dessert without eating their vegetables, compared to figuring out if someone called a locksmith or not because they forgot their keys.
What strikes me here, is that without any "training" we can easily distinguish one scenario from another, when logically they are equal. This seems to mean that we are designed to be able to pick out when someone is getting something they don't deserve or haven't earnt, I guess you can say we're all designed to keep the playing field fair. Interesting thing is, as far as I know this isn't the only thing we're hard-wired with. I remember in psychology, we learnt that humans can be taught to fear spiders more easily than say, a wooden chair. So somehow we learn to fear things that are potentially more dangerous to us more easily. Evolutionarily, this all makes sense. Making sure someone doesn't get all the benefits without doing the work. Making sure that we quickly learn to 'fear' what may potentially kill us. Though that makes me wonder, how many other things are we, as humans more prone to being able to accomplish, learn and execute?
Not only could they not communicate, but they were left without a code to think in.
~ How Deaf People Think
This post is long overdue and thus it has been quite sometime since reading the article, but still something to think about. After reading this article, I realised that I had never quite thought of how one who has never heard sound would think in their mind. When random thoughts float around my mind, they are definitely quite literally a "voice" that is there blabbering away. It made sense that deaf people's inner "voice" would be how they normally communicate - sign language, but I still somehow find it mind boggling!
After reading the article, I thought to myself - what would I do if I did not have an inner voice? Would I still be able to think? I know this isn't the focus of the article, but the thought was probably triggered by the section about deaf people who were forced to communicate only via spoken language and therefore never really formed an inner voice. Luckily research has found that forcing deaf people to communicate exclusively with spoken language only is detrimental to their brain development.
It is good that with more knowledge people are (hopefully) not being forced to do something they are not naturally inclined to do. I for one cannot imagine not having an inner voice or some way to talk to myself and think in my head.
"Time (noun): [mass noun] the indefinite continued progress of existence and events in the past, present, and future regarded as a whole." -Oxford Dictionary
Time is a funny thing. We, as humans, all seem to be aware of the concept of time. What time did you wake up? What time is dinner? When will the train leave? How long is the movie? We have units to measure time - seconds, minutes, hours, days etc. Despite these well defined units of measurement, I feel time seems to be a very flexible and almost completely open to interpretation...
We are all human, yet we are all different from each other, we are all unique; or as someone put it "You are unique, just like everyone else." However, for the majority of us, no matter how "unique" we are, we are still human...which means most of us are susceptible to quirks in how our brain works.
So what is all this random rambling about? Well for those that are unaware, I enjoy understanding and learning how the human mind works - especially when it doesn't quite work as expected, such as when we see optical illusions. So here are a few that I would like to share.
Impossible Motion: Magnet-Like Slopes
Our brain doesn't always decipher what we see with our eyes in the real world properly. It tries to be too smart and often fails. But that's ok, since it means we can see awesome optical illusions!
You've probably heard of this before - as humans we can be very "blind" to how our environment changes around us. Some rather big changes can occur and we don't notice at all.
Another change blindness example - just for fun
Leaning Tower Illusion
So what about a still image, no videos, just a plain old image. How will your eyes (or should I say brain) trick you now?
That's it for now - hope you enjoyed the random selection above What I find most interesting is that for many of these "brain quirks" even though you know what is happening, even though you know the trick you still can't un-trick your brain to see what is really there.
Another hot week in Sydney and another week closer to the end of 2009!
Sunday, 22 November 2009
#326 - Hot weather makes me feel lazy.
Today was a super hot and humid day in Sydney and I just simply felt like doing nothing at all. The day was indeed a very lazy day, just sat at my desk doing not much at all. In fact halfway through the day I just decided to lie down and sleep, though not much longer afterwards I woke up because it was too hot. Tried googling to see if there was any explanations to why hot weather makes people sleepy or lazy, but unfortunately didn't come up with anything useful other than a random comment on a forum saying "Cold weather makes me sleepy too. Being awake makes me feel sleepy."
This week has come and gone, and somehow I don't feel as productive as I would have wanted to be. Maybe it is the stinky hot weather or maybe the time just slipped away, but either way yet another week has passed by. Hopefully I'll be able to use my time more effectively this coming week. As for the the Week 47 musings...
Sunday, 15 November 2009
#319 - Two things: Fast decision making can be critical at times and people can sometimes think very irrationally...
I was standing at the train station today waiting for the train and looking at a group of three people who were just talking to each other. Suddenly one of them accidentally drops their phone (an old Nokia 3315), all three look down at the phone, then one of them stepped forward to pick the phone up. Except when he stepped forward he kicked the phone down onto the train tracks. Now all three were staring at the train tracks. At the same time the announcement overhead starts "The train arriving at platform three...", the group looks to their right and indeed a train is coming.
So what do they do? One of them is just standing there seemingly still deciding whether he should go and grab the phone or not; the other jumps down to grab the phone while the other is yelling "leave the phone!". Luckily the guy that jumped down to grab the phone jumped back up before the train passed - he had probably only 1 or 2 seconds to spare. The fast decision made by the guy that jumped down meant that he was able to get the phone and be safe (had he hesitated he would not have made it in time), but on the other hand, I feel that it was a rather silly decision to make - risk your life for a phone.
Yet another week has flown by and we find ourselves already halfway through November! This post is a day late due to my lack of Internet/computer use over the weekend. For those who are curious as to why it is Musing #46...read on
Sunday, 8 November 2009
#312 - There is actually a ISO standard (ISO 8601) that covers the "representation of dates and times"
In my attempt to give my weekly musings a bit more structure, I looked up what day and week of the year we were in. The day of the year was simple enough, but the week was actually more complicated that I thought it was! I always assumed that 1st January will be Week 1..but then thinking about it, if 1st January is a Friday, will it still be Week 1? According to ISO 8601, if 1st January is a Friday, Saturday or Sunday it is actually Week 52 or Week 53 of the previous year (ISO 8601 week starts on Monday). To confuse things even further, the system followed by USA is different to ISO 8601 - weeks start Monday, and there are partial weeks at the start/end of the year. If you're wondering, 09/11/2009 is Week 46 and the reason I start on Sundays for these posts is so I can have Sunday to write them up, and it's no fun to come up with the musing for the day and write about it on the same day.
The image above probably looks very normal - a set of everyday chess pieces (without pawns). White pieces on top covered by black clouds, and black pieces at the bottom covered by white clouds. If they don't look like chess pieces, try clicking on the picture to enlarge it - my friend thought they were teeth when he saw it on my msn display pic!
So, if we are imaginative, and assume the chess pieces are real, it would make sense that we can use them and play a normal game of chess...right? Well, not quite - because the chess pieces are identical. They are the same - pixel for pixel. If you don't believe me 'cut and paste' the chess pieces and they will magically "change colour". Even if you believe me you can give it a go, quite mind blowing if you ask me!
Was going to post this up last week, but then saw the free penguin/tux and I just had to post that first Anyway, this is the first of hopefully many cool optical illusions that I will post up. I love optical illusions, and I'm going to try and post up "rare" illusions on my blog - so stay tuned!
In my opinion, this illusion is extra cool because nothing was done deliberately to get the illusion effect. The photo was actually taken by Marty, and every now and then it appears on her laptop slideshow screensaver (everytime it appears I point at it and go psycho )