A Nobel Encounter

Attended the last day of the Physics Symposium yesterday, listened to a the lecture given by a Nobel Laureate, Robert Laughlin. Was profoundly affected by what the said about physicist's view of the world being too tainted by their unverifiable believes, such as the belief that the world has to follow nice and cushy simple rules. He cautioned that this might not be the case, and that the laws of physics might well arise as a consequence of the collective behavior of stuff...

As an aspiring physicist, who has chosen to do physics because of the plausibiilty that we are on the verge of the holy grail of knowledge, that is the fundamental laws of the universe, hearing this proposition for the first time was alarming, as it has very disturbing implications.

One of which is that the universe is complex even at the deeper levels (in such a case, there would be no such thing as the deepest, or most fundamental principle). Prof Laughin educated us that smashing particles in the very controlled environment of the particle accelerator yielded as diverse a result as smashing rocks together, thus implying that we may not be any nearer to the fundamental laws of nature.

So I approached Prof Laughin and expressed this concern to him. Laughin responded by relating a story about how he had a discussion with a Marxist friend who believed in the simple, elegant laws of Marxism, although it does not agree with the reality. The moral of his story is that one should not be blinded by personal believes, to the extent that one misses hard experimental facts. And to quote him verbatim,

"True Physics is Experimental.
If you want to be a Real Physicist,
You'd have to be an Experimentalist!"

Well, I guess I'll bear these words of wisdom in mind when I approach physics in future. Though I might still hold on to the hope that the world is fundamentally elegant as there is no compelling proof that it isn't, and this hope is a very strong motivation to understand nature.

Alright, enough talk about a Laureate,

lau·re·ate (lôr'ē-ĭt, lŏr'-)
adj.

1. Worthy of the greatest honor or distinction: “The nation's pediatrician laureate is preparing to lay down his black bag” (James Traub).
2. Crowned or decked with laurel as a mark of honor.
3. Archaic. Made of laurel sprigs, as a wreath or crown.

n.

1. One honored or awarded a prize for great achievements especially in the arts or sciences: a Nobel laureate.
2. A poet laureate.

[Middle English, from Latin laureātus, adorned with laurel, from laurea, crown of laurel, from feminine of laureus, of laurel, from laurus, laurel.]
lau're·ate·ship' n.

I also attended a lecture on Quantum Infomatics given by Prof Artur Ekert (He's from Cambridge!) . It was a very stimulating lecture, the most engaging in this series I attended. At the very least, I gained an idea about how all these quantum mechinical experiments are performed technically. Though there are many parts I don't quite understand...

From what I gather, a useful quantum phenomen is Entanglement. Entanglement provides a way to generate random numbers, which can be recieved by only 2 parties. And thus can act as a secret key by which one can encrypt infomation.

Exactly how Entanglement is performed still eludes me. I know that entangled particles are created by a novel process that neccessarily produces identicle particles(how?!). For most discussions, the particle in question was a photon. And some property of the particle is random, this property must be able to represent a value. For the case of the photon, it is the polarity(why?!). When the entangled photons are created, it's polarity is random and not known, the value it represents exists as a superposition of all the possible values, until one photon is measured, then because of the quantum phenomenom, the superposition of states of the other particle also collapses. I'm not exactly sure how this would prevent potential evesdroppers though, I asked the Prof, and he said that the answer would lie in some kind of protocol could exploit this phenomenom...

As for the technical aspects, I was vaguely told that an entangled pair of photons can be created by sending a pulse of light into a crystal, which would excite an electron that would subsequently fall 2 energy levels and in the process release a pair of entangled photons. How it can be made to fall 2 energy levels and create entangled photons, still baffles me. I also learnt that the photons are typically transmitted through optical fibres, and that entangled photons have been routinely transmitted up to a distance of 30 km.


Still on the topic of quantum physics, Prof Laughin mentioned a few times about asking the right question...

Then it occured to me regarding Schrodinger's Cat:
Instead of simply asking

"whether the cat is dead or alive",

you extended the question to

"if the cat is dead, when did it die?"

Would one be able to determine such a property as an event in the quantum context?

I reckon it would be as difficult to answer as the question

"if it is alive, when will it die?"