Posts

Relocating to Hong Kong

Just over two years ago, I wrote a post about relocating to Sydney.  Little did I know then that I will be writing a similar post today with Hong Kong as my next destination.  Life is certainly an adventure and I really enjoy not knowing the surprises that are in store! Anyway, I will spend my last three weeks here wrapping up the 9-5 and enjoying the little things Sydney has to offer.  Hope this will not affect my blogging too much. -PTS

Another Earthquake in New Zealand

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A magnitude-6.3 earthquake today hit Christchurch, New Zealand. Although less powerful than the one that struck in September last year, it is much more devastating. Many buildings in the city were demolished, including its iconic cathedral. The casualty toll currently stands at 63, but is expected to climb above 100 in the next few days. Today's earthquake struck 45km west of the city and is only 5km below the surface. This aftershock is much closer than the quake that registered five months earlier. My condolences to those affected and I hope the city can rebuild from this unfortunate episode! -PTS

Watson Beats Human Champs on Jeopardy!

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It is official: IBM's Watson, a supercomputer equipped with terabytes of RAM, was crowned champion of champions on Jeopardy this week. It smashed the show's two most accomplished human Jeopardy contestants ever by a mile. Prior to this challenge, Ken Jen and Brad Rutter both won over $3M USD on Jeopardy! It is amazing how far artificial intelligence has come over the years.  I was especially impressed with Watson's ability to interpret the play of words often found in Jeopardy-styled clues (or answers). Apart from the occasional mishaps when it completely missed the mark, Watson did extremely well even in categories like "Familiar Sayings" that require a certain level of intuition.  Enjoy this clip on the final 10 minutes of the competition: In 1997, IBM's Deep Blue defeated fellow human grand masters like Garry Kasporav. Fourteen years later, we have a Jeopardy champ that does not require food or sleep.  One cannot help but wonder what next to expect in

Tropical Cyclones

Tropical Cyclone Yasi hit Queensland, Australia a few days ago, causing millions of dollars in damages.  The silver lining in this unfortunate episode, is that it missed areas of concentrated populations. It is worth noting that the sheer size of the weather system would have wreaked much more havoc  had it hit elsewhere.   What is a Tropical Cyclone A tropical cyclone is essentially a spiraling mass of wet air centred around an area of low atmospheric pressure most commonly known as the "eye". On the ocean, a cyclone is continually fed as evaporated water from the ocean surface condenses, releasing more heat as the air current rises. Owing to the  Coriolis effect , a cyclone spins counterclockwise in the Northern Hemisphere and clockwise in the Souther Hemisphere. Strength Categories According to the Saffir-Simpson Hurricane Scale, Yasi was a category 5 cyclone, the strongest of its kind. It reached wind speeds of 250km/h, and storm surges of greater than 18ft. Ca

The Physics of Whip Cracking

I tried my hands on whip cracking in an Aussie sheep farm tour late last year.  Interestingly, whip cracking in Australia has gained enough prominence to be a competitive sport! I must admit that the whip is not my forte, as I could only get it cracking 10% of the time (when I am not hitting myself with it).  Staring at defeat, I decided to learn the science behind this in hope of conquering it some day. It turns out a whip cracks because a sonic boom is created at its tip or topper. A sonic boom is created when an object travels at supersonic speeds such that its surrounding waves of air pressure are compressed into a single shock wave at the speed of sound. The logical question then: what is travelling so fast in the whip? Well, it's the tip. Why? Conservation of momentum! Let's picture this: when you apply a force to a whip, the initial loop motion and wave are applied to the thong, which has a much larger mass than the whip's tip. It is worth noting that momentum i

Prime Numbers and Encryption

Want to make   $250 000 ?  Find a big prime number, a really big one. It turns out there are organizations  ready to dough out good cash for a really large prime number.  This is because primes are used in   RSA cryptography . RSA Algorithm Let's look at the algorithm: 1.       Multiply two large prime numbers  p  and  q  to get the product  N 2.       Find two numbers  e  and  d , such that  ed = 1mod((p-1)(q-1)) , where  e  and  N  are relatively prime meaning they do not share any prime factors. 3.       Let's call  M  the original message and  C  the ciphered message:  a.       To encrypt: C = M e mod(N) b.       To decipher: M = C d mod(N)  In essence, using the public key   ( N,e)  will transform the original message   M   to the ciphered message  C . On the contrary, applying the private key  d  on the ciphered message   C  will result in the original message   M .  Security of Encryption The beauty of RSA is your public key can be published for anyone to

The Colours of Water - From The Caribbean to the South Pacific

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Last year, I took a number of vacations which involved cruising, diving, snorkelling and walking on glaciers. Thinking back on those trips, I could not help but notice that water and ice exhibited different colours in different settings.  I decided to dive deeper into the colours of water. Finally, here are my findings. Water’s True Colour The colour of an object mainly depends on the colour of light emitted from it. In the case of water its colour is also affected by factors like light source, absorption, scattering, and suspended materials. Absorption by water is stronger for red light, but weaker for blue light. Water is therefore, intrinsically blue. However, this effect is only apparent when the water is reasonably deep. This is why a glass of water appears colourless whereas a big aquarium looks bluish through the thickness of water. Why is the Sea Blue? I did two cruises last year, one in the Caribbean and the other in the South Pacific. Owing to the depth of the water, th