Friday, November 23, 2007
Where have I left off
University stresses me off right now. Stacks of work. Canteen food is crap - not as good as home food anyways.
This post will be about food I prepared for lunch and dinner today.
LUNCH -
DINNER -
By the way, I am so pissed off on my neighbour who spilled all my blueberries on the floor...
Wednesday, May 30, 2007
Thursday, May 17, 2007
Wednesday, May 16, 2007
This is hard! solution
First let u = 1 - 3x - 2x^2.
Then du/dx = -3 - 4x
So, force the numerator into -3 - 4x, like so:
1 + 2x = -1/2(-2 - 4x) = -1/2(-3 - 4x + 1) = - 1/2(-3 - 4x) - 1/2
Hence, the integral must be split into two integrals, one relatively easy to solve by chain rule since numerator is derivative of the denominator.
First one easily solved using chain rule (or by inspection), and the second one needs a bit more working. Can change the second integral to a standard form if you complete the square and take the factor of 1/sqrt2 out.
Then just use arcsine to finish it off!
Monday, May 14, 2007
This is hard!
I won't even bother solving it here using this stupid keyboard, but a tip: hyperbolics. And if you actually bother solving this - then how about writing the working and solution in LaTeX, and I could copy and paste it here so that everyone could enjoy the maths! :)
Saturday, April 28, 2007
Monday, April 23, 2007
Book recommedation
It talks about very interesting topics such as how chocoloate chip cookies contain more chemical energy per gram than TNT and yet it is not used as a weapon, or how the "flying disks" in the Roswell incident are just microphones to detect noise from nuclear bombs.
So, learn more physics without losing interest in it!
Buy from Amazon.com: http://www.amazon.com/Physics-Future-Presidents-Richard-Muller/dp/142662459X
Alternatively, you could watch Richard's lectures FOR FREE: http://webcast.berkeley.edu/course_details.php?seriesid=1906978373
You could thank me later. Back to more boring A-level physics revision.
Wednesday, April 18, 2007
Shock, horror, and sadness
By now, you should already know about the massacre in Virginia Tech University. Thirty-three people were killed, whom were either students or professors. We are unwillingly reminded that these horrific events could occur at any time, in any place...
Thursday, April 05, 2007
Rat monkey depression
This is the point when you either read on or leave this website or watch the video below, then leave.
Yes, I am depressed today. Even the video above doesn't cheer me up. I won't go into the reasons behind this depression - there are just too many, and they are probably irrational anyways. When you are depressed, well, when I am depressed, I am tired, unmotivated, bored. I feel like time is slowed down - everyone's minding their own business and probably having fun, while I sulk... in my bedroom... all day. I haven't done much today - I woke up very late, took a shower, ate, sat, ate. So yeah, not a good day today.
Depression. Depressed. Logically speaking, they should be happy words. Pressed is like stressed, and depressed seems like you are relieved. But no, it's a sad sad word. Anyways, when you are depressed, you also don't know what you talking about. You have bad dreams. I've dreamt about having to do essays for homework for two nights in a row - and they are english literature ones too! How screwed up is this? I don't even take english literature anymore - and for some twisted reason they haunt me in my dreams.
Let me check the dictionary to see whether I am actually depressed:
• noun
1 severe despondency and dejection, especially when long-lasting and accompanied by physical symptoms.
2 a long and severe recession in an economy or market.
3 the action of depressing.
4 a sunken place or hollow.
5 Meteorology a cyclonic weather system.
I think I could ignore two to five. But what the hell is despondency and dejection! God damn it!
despondent
• adjective in low spirits from loss of hope or courage.
dejection
• verb sadness or low sprits.
Well, I am kind of despondent in a way - low spirits definitely, don't know if I have loss of hope/courage though. Hope for what? I have nothing to hope for! Dejection - yes.
So I am definitely depressed. And this is going to last for quite a long time. Until something drastic happens - I mean when I win a lottery ten times in a row as opposed to experiencing a car crash.
Nobody said there was going to be a good ending!
Bye!
Edit: Not so depressed anymore. :)
Saturday, March 31, 2007
Magnetism: Ferro, Para, Dia
No interesting video clip to show. Just find your own magnet!
PARA | Paramagnetism is a form of magnetism which occurs only in the presence of an externally applied magnetic field. Paramagnetic materials are attracted to magnetic fields, hence have a relative magnetic permeability greater than unity (or, equivalently, a positive magnetic susceptibility). However, unlike ferromagnets which are also attracted to magnetic fields, paramagnets do not retain any magnetisation in the absence of an externally applied magnetic field.
Elements/compounds could be paramagnetic if they have unpaired electrons. The following are some examples of paramagnetic elements:
Aluminium Al [13] (metal)
Barium Ba [56] (metal)
Oxygen. O [8] (non-metal)
Platinum Pt [78] (metal)
Sodium Na [11] (metal)
Strontium Sr [38] (metal)
Uranium U [92] (metal)
Technetium Tc [43] (artificial)
Compounds
Many salts of the d and f transitional metal group show paramagnetic behaviour. Examples are:
Copper sulphate
Dysprosium oxide
Ferric chloride
Ferric oxide
Holmium oxide
Manganese chloride
The below video clip shows a liquid oxygen bridge suspended by a strong u-shaped magnet. This demonstrates the fact that magnetic force > gravitational force.
DIA | "This is a live frog. An object does not need to be superconducting to levitate. Normal things, even humans, can do it as well, if placed in a strong magnetic field. Although the majority of ordinary materials, such as wood or plastic, seem to be non-magnetic, they, too, expel a very small portion (0.00001) of an applied magnetic field, i.e. exhibit very weak diamagnetism. The molecular magnetism is very weak (millions times weaker than ferromagnetism) and usually remains unnoticed in everyday life, thereby producing the wrong impression that materials around us are mainly nonmagnetic. But they are all magnetic. It is just that magnetic fields required to levitate all these "nonmagnetic" materials have to be approximately 100 times larger than for the case of, say, superconductors. This experiment was conducted at the Nijmegen High Field Magnet Laboratory."
A large black superconducting disk was cooled with liquid nitrogen. When the disk goes into the superconducting state it expels magnetic field. This is called perfect diamagnetism. If you place a magnet above the disk when it is superconducting then it will levitate. This is known as the Meissner effect.
[99% Wikipedia and YouTube.]
Friday, March 30, 2007
Chemistry degrees
Bristol
Friday February 16, 2007
"It is 9am on a Monday morning and 60 or so third-year chemistry students are already in their seats, files and pencil cases at the ready. Dr Chris Russell - young and dressed in a brown-striped shirt and chinos - will be our guide to inorganic chemistry for the next 50 minutes. And he's off, chalk flying!
Russell talks about "planar ML3 and ML2 fragments", "ligands" and "non-bonding orbitals" with clarity and enthusiasm. It is all entirely familiar to me - and yet utter gobbledegook.
Russell draws pretty, floaty diagrams on the blackboard with Ls and Ms and dots. L must stand for "ligand", whatever that is. But M? There is a periodic table on a wall of the lecture hall, but there is no M on it. Then Russell mentions "transitional metal chemistry", and the truth dawns: M stands for "metal", and I am, by any measure, the dumbest person in the room.
I studied at Bristol's school of chemistry from 1988 to 1991. I chose chemistry for a bunch of non-reasons - it was like, you know, one of my A-levels, and I was like, 18, and did not have a clue what I wanted to do with my life. In the event, it proved to be the exact opposite of a doss: both difficult and staggeringly time-consuming. It was a 9-to-5 business, five days a week.
Back in my day, the course was divided into three disciplines: copying, swotting and lab survival. In lectures there was no time for comprehension: our task was to accurately copy down reams of scribbled diagrams and equations from the blackboard. If you skipped a lecture, it would take at least 50 minutes to copy someone else's notes, and then you could never be sure that they hadn't made some awful error. (I wonder now why we never used a photocopier, but then this was at a time when undergraduates had no access to computers: I saw my first one two years after leaving university.)
Then there was the swotting: revising for exams became the time when you had to make sense of your notes, and that took out months of our lives. And finally there were the labs, where we spent our afternoons - a quite literally explosive mixture of deadly chemicals, teetering glassware, open flames and blind panic. It was all deeply Victorian, and we work-shy children of the 1970s were made to feel like proper no-marks most of the time.
University science is now in real crisis - particularly the non-telegenic, non-ology bits of it such as chemistry. Since 1996, 28 universities have stopped offering chemistry degrees, according to the Royal Society of Chemistry.
The society predicts that as few as six departments (those at Oxford, Durham, Cambridge, Imperial, UCL, and Bristol) could remain open by 2014. Most recently, Exeter University closed down its chemistry department, blaming it on "market forces", and Bristol took in some of the refugees.
The closures have been blamed on a fall in student applications, but money is a factor: chemistry degrees are expensive to provide - compared with English, for example - and some scientists say that the way the government concentrates research funding on a small number of top departments, such as Bristol, exacerbates the problem. The upshot is that Britain is turning out fewer and fewer chemists - even though there are jobs for them. Against this backdrop, it seems quite important that chemistry teaching is making an attempt to pull itself into the present; that it is as engaging as it can be; that it is no longer quite the dusty experience that it was in the early 90s.
Back in lecture theatre two, Russell is talking about "delta symmetry orbitals". You can see that he cares. He is one of the most popular lecturers here, the students tell me later.
All these students, I realise, have arrived with the notes for this lecture already in their possession - printed out from a website that also provides them with sample exam questions and workshop material. Their only job here is to annotate their notes if asked to. What a brilliant leap forward. The death of the science of copying. Later, a professor tells me that the real problem now is to keep the students' attention for the full 50 minutes.
Suddenly, a word that normal people and even journalists have heard of ... "Polonium is named after Poland," says Russell. "But that's by the way," he adds. We're back to ligands.
At 10am I have a physical chemistry tutorial with three first-year students. We sit around a little table. The students seem very young, and sweet, the bloom still fresh on them. Professor Andrew Orr-Ewing is quietly spoken, calm and super-clear. We work through a set of questions that cover the "particle in a box theory" and "tunneling effects". I sit frozen with terror, in case Orr-Ewing asks me a question and it becomes clear that I have forgotten everything I learned here. When he asks the students questions, I flinch for them, but they seem to know their stuff . There is no way I would have been so sharp in my first year here - what has happened to undergraduates?
Lisette Voûte is 21 and a third year; she is doing a four-year version of the course and will emerge next year with an MSci. She is of the opinion that chemistry's rigours are an excellent foundation for life, and says, "It's a great degree to have."
She is positive about the way it is taught, and says you can now complain if lecturers are rubbish. But then Voûte went into this knowing what she would be up against, and she knows what she wants to do at the end of it: she is the exact opposite of the hopelessness that was me at 21. Maybe all those debts and top-up fees have made students more wised-up. Then I meet another student, who asks not to be named. Why did he do chemistry? He is not sure. Does he like it? No - it is "baffling", and if he'd had any idea how hard it would be, he wouldn't have done it. What will he do next? He doesn't know. This could be me, 16 years ago. "But these are meant to be the best years of your life, right?" he says.
"God no!" I say. "I was miserable at university. I made a mess of everything. My private life was a car crash. I didn't like my course. I felt totally useless. Of course I'm a million times happier now!" He looks at me - an ancient person, on the verge of Zimmer-dom - and I can see that he is not convinced.
Later, when I meet up with my former organic chemistry lecturer, Dr Lionel Hart, I ask him if students have changed since he first started teaching? "No, not at all," he says. "They're just the same."
Bristol's school of chemistry, once a monument to 60s concrete, has had a face-lift since my time here - from the outside, it looks less like a Doctor Who set than it did. There is a new reception area. And the department has just been fitted out with state-of-the-art labs - though it turns out that even the old labs are pretty fancy these days. Someone has decided that wooden benches encrusted with decades' worth of toxins are not a brilliant idea in a human-rich setting, and they have all been replaced with gleaming white counters and computers. Lab specs have changed too. Out go the NHS clear plastic ones, in come bendy ones with blue piping. The labs still stink of solvents though - which really can't be a good thing.
Meanwhile Dr Paul Wyatt, the director of undergraduate studies, has come up with a computer programme that will soon allow undergraduates to practise experiments in a virtual setting before they get into the lab. This will be another big step forward - especially as doing your experiments first on the computer will be heavily compulsory.
It will still be lab though. And it will still be really hard. On the train home, it occurs to me that perhaps the building blocks of chemistry are, necessarily, inescapably hard and dry. However many computer tricks they come up with, however shiny the labs, perhaps undergraduate chemistry is simply un-sex-uppable. There is stuff you need to learn if you are going to be a chemist, and there is a lot of it, and it is difficult. And that's the deal, even though, these days, that is not the sort of deal people relish. Perhaps only Voûte's view - that courses such as chemistry are "good" degrees to have - can save us from becoming a nation with no idea what an atom is."
Source
Thursday, March 29, 2007
Tuesday, March 27, 2007
Tuesday, March 20, 2007
Why base 10?
Obviously, because we have 10 fingers. But that's kind of selfish of us - and should I also say not very mathematical. Tens do not occur often in nature anyways - it just so happens that we have 10 fingers.
Interestingly, before base 10 was universally used, base 11, 12, and 20 have been used. This is shown in our languages. E.g. eleven, twelve, as opposed to oneteen, twoteen; or vingt and quatre-vingt in french.
Base 2 is singled out as the one with the smallest possible base. Only digits 1 and 0 are used. Every other number could be represented by 1's and 0's. So that 1 + 1 = 10 and 1 * 1 = 1. The obvious disadvantage of this binary system is that long expressions are needed to represent even small numbers. E.g. 79 is expressed as 1001111, which is really 7*10^1 + 9*10^0 = 1*2^6 + 0*2^5 + 0*2^4 + 1*2^3 + 1*2^2 + 1*2^1 + 1*2^0. But multiplication is very easy. And other possible problems may also be easily solved with binary. Is this what God uses?
Sunday, March 04, 2007
American view?
Tuesday, February 27, 2007
Monday, February 26, 2007
Friday, February 23, 2007
What if...
Wednesday, February 21, 2007
A collection of science jokes: Part 1
The biologist said: "I want to study the coral structure of the sea". So he went into the sea never to be seen again.
The physicist said: "i want to study the physics of the sea wave".' So he went into the sea and was carried away by the current never to be seen again
The chemist took out a pen and paper and wrote down: "Both biologist and physicist are soluble in water."
-
An pair of atoms are walking down a street. One says to the other "I think I've lost an electron!" "Are you sure?" said the other. "Im positive!"
Another atom finds the electron and says "I'll keep an Ion it for you"
-
An atom says to a shopkeeper, "How much are these neutrons?" He replies "Oh them, they're free of charge"
-
My names Bond. Ionic Bond. Taken, not shared.
-
There is this farmer who is having problems with his chickens. All of the sudden, they are all getting very sick and he doesn't know what is wrong with them. After trying all conventional means, he calls a biologist, a chemist, and a physicist to see if they can figure out what is wrong. So the biologist looks at the chickens, examines them a bit, and says he has no clue what could be wrong with them. Then the chemist takes some tests and makes some measurements, but he can't come to any conclusions either. So the physicist tries. He stands there and looks at the chickens for a long time without touching them or anything. Then all of the sudden he starts scribbling away in a notebook. Finally, after several gruesome calculations, he exclaims, "I've got it! But it only works for spherical chickens in a vacuum."
-
Q: What is the name of the molecule CH2O?
A: Seawater
-
To end with a historical note:
In the 1980's, in an effort to increase public awareness about the importance of chemistry, the American Chemical Society posted billboards with a picture of C6H10 and the title, "It takes alkynes to make a world."
Saturday, February 17, 2007
Friday, February 16, 2007
Derivation of the most beautiful identity
I want to share this with you. The derivation of one of my favourite identites in mathematics so far:
Let f(x) = cos x = a + bx + cx^2 + dx^3 + ex^4 + fx^5 + ...
(don't mix up e in ex^4 with e = 2.7182821828...; in this case e is just any constant)
so
f(0) = cos 0 = 1 = a, thus a = 1
f'(x) = -sinx = b + 2cx + 3dx^2 + 4ex^3 + 5fx^4 + ...
f'(0) = -sin0 = 0 = b; thus b = 0
f''(x) = -cosx = (2*1)c + (3*2)d + (4*3)ex^2 + (5*4)fx^3 + ...
f''(0) = -cos0 = -1 = (2*1)c; thus c = -1/(2*1) = -1/2!
f'''(x) = sinx = (3*2*1)d + (4*3*2)ex + (5*4*3)fx^2 + ...
f'''(0) = sin0 = 0 = (3*2*1)d; thus d = 0
f''''(x) = cosx = (4*3*2*1)e + (5*4*3*2)fx + ...
f''''(0) = cos0 = 1 = (4*3*2*1)e; thus e = 1/4!
...
and so on.
Therefore substuting the constants into the original polynomial equation,
(i) cos x = 1 - x^2/2! + x^4/4! - x^6/6! + x^8/8! + ...
You can check this by substitution a value in x, such as 1 (radians).
Similarly, you can work out an expansion for
(ii) sin x = x - x^3/3! + x^5/5! - x^7/7! + x^9/9! + ...
(iii) e^x = 1 + x + x^2/2! + x^3/3! + x^4/4! + x^5/5! + ...
Now using expansion (iii), you can expand e^(ix), where i = √(-1)
(iv) e^(ix) = 1 + ix + (ix)^2/2! + (ix)^3/3! + (ix)^4/4! + (ix)^5/5! + ...
= 1 + ix - x^2/2! - i(x)^3/3! + x^4/4! + i(x)^5/5! + ...
Separating the imaginary parts and real parts,
e^(ix) = (1 - x^2/2! + x^4/4! - x^6/6! + ...) + i(x - x^3/3! + x^5/5! - x^7/7! + ...)
= cos x + isin x
Wow!
so you get Euler's identity
And a special case of it, is when x = π
e(iπ) = cosπ + isinπ = -1 + i(0) = -1
Rearrange, then you get
an equation connecting the fundamental numbers i, π, e, 1, and 0 (zero), the fundamental operations +, ×, and exponentiation, the most important relation =, and nothing else.
Wow! Wow! Aren't you excited? (Nerd... if you actually read through all of the above and understood it.)
Gauss is reported to have commented that if this formula was not immediately obvious, the reader would never be a first-class mathematician.
It doesn't stop here though.
This opens a lot of branches in mathematics. One example is the hyperbolic function, which links circular and exponential functions - something you usually think as very separate branches of mathematics.
Friday, February 09, 2007
Fried rice kung fu!
Yum...
If only I could produce that fried rice everyday, I could save money at university (+ avoid eating crappy food). I could also sell my fried rice. I could take over the university canteen. Hahaha
I better start cooking now! Hai ya! Hai ya! Hai ya!
Video from averagebetty.
Get the fried rice recipe from the fried rice demon.
Thursday, February 08, 2007
Tuesday, February 06, 2007
Tutoring - Day #1 and #2
And, well so far it was crap. Better than expected. Actually you know what - maybe for a nine year old, it's quite good. He's polite but extremely hyperactive - so it seems that more than half of what I say to him goes out the other ear. What I mean by hyperactive: throwing basketballs, blowing air with his basketball pump, playing with his sportsband - you love basketball - I get it!
Right now, I am teaching him English, Maths and General studies. Wow! I must say kids these days learn a lot of things! Too much too soon, in fact. For example, in general studies, he already learns about annular solar eclipses and refraction of light! And in maths - manipulation (addition/multiplication all of that) of decimals and fractions? That's what we did in secondary school - not in primary?!
My rule of thumb: Less is MORE.
So yeah, he's not doing very well - and I can understand why. Duh? How can he absorb all that information. There must be something wrong with the syllabus. And the teaching at school too. He says (let's call him David from now on) that he must follow exactly what the textbook (word for word) says or else the teacher will mark him wrong. What kind of learning is that? Copy and paste? Okay, you might be smarter than most people your age (compared to say, the ones in international school - he goes to a local school) in terms of lots of knowledge - but as soon as I change the wording of a question (from the textbook) he would be like "Huh? I don't know! It's not even in the textbook!" And by the way, I am not blaming the students - I am blaming the teachers and education board in general.
Maybe I am expecting too much. But maybe I'm not. Education nowadays is getting worse, and creativity and thinking-out-of-the-box are deminishing. A lot.
No wonder why most children nowadays don't want to go to school.
Well, I guess this is where I come in. We'll see how things go.
Saturday, February 03, 2007
Uneventful day?
And I was planning to stay at home. Watching TV, taking a very very long bubble bath, whatever.
But then my neighbour, whose son I tutor, called me to go to her place to help her son with some homework. So I left home, sigh, but I thought to myself this should be quick. And sure it was quick.
Joyfully, I went back home. And then crap! I forgot to bring the keys! And usually there was somebody at home! But NOBODY this time! CRAP! I was at that moment the unluckiest person on earth! This unlocking-myself-out-of home-accidentally actually happened a few times. But come on - a weekend. For the whole day?!?
And.... well nothing good after that.
I walked around to pass time...
and froze to death.
Sunday, January 28, 2007
Tennis + question
In the spirit of tennis, here's a question for you:
One thousand and twenty four tennis players compete in a singles competition (one player play against another - loser cannot play any further, winner stays in the game and play another winner, etc.). Assuming all players play, how many games are there until there is a champion?
Monday, January 15, 2007
Time and money
...since I don't have enough money to buy...
Actually, I don't even know how much the first watch costs, might not even afford it.
Ok, just checked the price for the first watch: $2000 US!! I can only wonder how much the Cartier costs. That's it! I will rely on the sun to keep track of time from now on!
Sigh... time > money
Tuesday, January 09, 2007
Gold is not forever with aqua regia
Aqua regia, a mixture of hydrochloric acid and nitric acid, can dissolve gold because each of its two component acids carries out a different function. The nitric acid is a good oxidising agent. Chloride ions from the hydrochloric acid from coordination complexes with the gold ions, removing them from solution. Reducing the concentration of the Au3+ ions shifts the equilibrium towards the oxidised form.
Au(s) + 3NO3-(aq) + 6H+(aq) ---> Au3+(aq) + 3NO2(g) + 3H2O(l)
Au3+ (aq) + 4Cl-(a) ---> AuCl4-(aq)
Friday, January 05, 2007
Calories and so on
As a rough guide, 1 joule is the amount of energy required to lift a one kilogram object up by a height of 10 centimetres on the surface of the Earth.
Or
The energy required to lift a small apple (102 g) one meter against Earth's gravity.
Or
In chemical energy stored in food.
Goodies: Celery (Apium graveolens dulce)
It is sometimes grouped as a low-calorie fibre bulk food. Not only does eating it will result in very few calories (actually negative, because digesting it requires more energy than the celery contains), it has a lot of vitamin C and fibre.
Baddies: Bacon (Sus scrofa domesticus)
Ewww.... I hate bacon. Not only does it tastes gross, it is full of fats: saturated, and worse unsaturated. Out of unsaturated fats, there are cis and trans fats (cis-trans or geometric isomerism - if you take chemistry).
Now it's the trans fats that we all talk about. Even your grandparents know what they are. Trans fats are bad for you! And indeed they are. It's all down to geometric isomerism. The C=C double bond in the trans isomer of the fat cause its rigidity and high density and make them hard to remove out of your body. I say they stay in your body forever (well a very long time)!
Anyways, some biology, some chemistry, some physics for you. What a happy post!
Wednesday, January 03, 2007
Foreign languages: oui or nein?
When I was fifteen or so, I attended language lessons solely because of exams. By then, I hated and dreaded language lessons!
As soon as I dropped languages at A-level, I was so relieved and happy! No more essays, stupid grammar, loads of vocabulary to learn, weird accents - extremely hard work really!
But unexpectedly, I kind of miss it now...
So, I am planning to brush up my foreign languages with the following podcasts. Feel free to do so too - these are for beginners. I will probably take up a foreign language at university too. I feel that knowing more languages open up so many more opportunities.
Podcasts
Deutsch (it's hilarious!): http://mygermanclass.com/
Français: http://frenchecole.libsyn.com/
Online dictionaries
Deutsch: LEO
Français: ARTFL
Tuesday, January 02, 2007
Exam frenzy
Monday, January 01, 2007
Happy New Year Everyone!
Fireworks | Laughter | Balloons | Champagne | Jumping people
We all deserve one!