Monday, April 16, 2007 5:23 pm
today was an ok day...
i mean there was maths...so naturally, i thought it wld suck.
but wasn;t so bad. :D
i got 19/20 for some maths test. stupid expansion/factorisation/solving quadratic eq. -.-
heng i did the bonus question. if not only 17. :)
and then she was like going through earlier wrkshts.
the only annoying thing during that time was xin zhan whom was sent out of class.
i sit at the corner of class. so the window is like a good friend to me. -.-
haha. for PE.
ran me 2.4 km. sucked lor.
13 05
thought i cld get better.
haha. jog 5 lap an' chiong the last one.
wei hao beat me by one sec. :(
nat, i think u should be able to beat me.
dang. haha. maybe.
today got guitar lesson.
i thought it wld suck. but quite alrite:)
i learnt some chords i was supposed to know LONG time ago,
but who cares... at least i learned smthg.
and.. haha i rather sing than play that damned varnished hollow chunk of wood.
then for chinese.
lao shi damn pissed cause nobody called her into the class.
she was like " ni men lei, wo bu lei meh?"
i was like whadafuck la. we did 2.4 km.
and like... bleah. we WERE tired.
then got the stupid lang du ce yan.
like i was almost goona get away with it.
then she chose me as the last reader.
%&^^%(!!
got 6 upon 10.
i dun give a crap la.
okayy.
now the cheem stuff. :))
Theory of relativitySpecial relativity
Main article: Special relativity
Special relativity is a theory of the structure of spacetime. It was introduced in Albert Einstein's 1905 paper "On the Electrodynamics of Moving Bodies". Special relativity is based on two postulates which are contradictory in classical mechanics:
The laws of physics are the same for all observers in uniform motion relative to one another (Galileo's principle of relativity),
The speed of light in a vacuum is the same for all observers, regardless of their relative motion or of the motion of the source of the light.
The resultant theory has many surprising consequences. Some of these are:
Time dilation: Moving clocks tick slower than an observer's "stationary" clock.
Length contraction: Objects are shorter along the direction in which they are moving.
Relativity of simultaneity: two events that appear simultaneous to an observer A will not be simultaneous to an observer B if B is moving with respect to A.
Mass-energy equivalence: per the relationship E = mc², energy and mass are equivalent and transmutable.
The defining feature of special relativity is the replacement of the Galilean transformations of classical mechanics by the Lorentz transformations. (See Maxwell's equations of electromagnetism and introduction to special relativity).
General relativity
Main article: General relativity
General relativity is a theory of gravitation developed by Einstein in the years 1907–1915.
The development of general relativity began with the equivalence principle, under which the states of accelerated motion and being at rest in a gravitational field (for example when standing of the surface of the Earth) are physically identical. The upshot of this is that free fall is inertial motion: In other words an object in free fall is falling because that is how objects move when there is no force being exerted on them, instead of this being due to the force of gravity as is the case in classical mechanics. This is incompatible with classical mechanics and special relativity because in those theories intertially moving objects cannot accelerate with respect to each other, but objects in free fall do so. To resolve this difficulty Einstein first proposed that spacetime is curved. In 1915, he devised the Einstein field equations which relate the curvature of spacetime with the mass, energy, and momentum within it.
Some of the consequences of general relativity are:
Time goes slower at lower gravitational potentials. This is called gravitational time dilation.
Orbits precess in a way unexpected in Newton's theory of gravity. (This has been observed in the orbit of Mercury and in binary pulsars).
Even rays of light (which are weightless) bend in the presence of a gravitational field.
The Universe is expanding, and the far parts of it are moving away from us faster than the speed of light.
Frame-dragging, in which a rotating mass "drags along" the space time around it.
Technically, general relativity is a metric theory of gravitation whose defining feature is its use of the Einstein field equations. The solutions of the field equations are metric tensors which define the topology of the spacetime and how objects move intertially.
im lazy to go find more cheem stuff. so thats it. :D
see yeah.
the day maths didn't screw up my day, since THAT day. :))
rain or shine,no matter what the clime,i'll bide my time,cause you'll always be mine.(come on go online!!)