Thursday, August 26, 2010

A New Relativity Theory? : By Shamsul Alam

We know that the relativity theory published by Einstein i 1915.. One student said that he watched one documentary about this theory on Discovery Channel and according to that documentary, there is a new theory of relativity. Really? Teacher never knows??? hehe...I mean I never heard about this before.

So, below is the information about the relativity theory..that I always use to explain my students.

Geometry of Newtonian gravity

At the base of classical mechanics is the notion that a body's motion can be described as a combination of free (or inertial) motion, and deviations from this free motion. Such deviations are caused by external forces acting on a body in accordance with Newton's second law of motion, which states that the net force acting on a body is equal to that body's (inertial) mass multiplied by its acceleration.[13] The preferred inertial motions are related to the geometry of space and time: in the standard reference frames of classical mechanics, objects in free motion move along straight lines at constant speed. In modern parlance, their paths are geodesics, straight world lines in spacetime.

Ball falling to the floor in an accelerating rocket (left), and on Earth (right)
Conversely, one might expect that inertial motions, once identified by observing the actual motions of bodies and making allowances for the external forces (such as electromagnetism or friction), can be used to define the geometry of space, as well as a time coordinate. However, there is an ambiguity once gravity comes into play. According to Newton's law of gravity, and independently verified by experiments such as that of Eötvös and its successors (see Eötvös experiment), there is a universality of free fall (also known as the weak equivalence principle, or the universal equality of inertial and passive-gravitational mass): the trajectory of a test body in free fall depends only on its position and initial speed, but not on any of its material properties.[15] A simplified version of this is embodied in Einstein's elevator experiment, illustrated in the figure on the right: for an observer in a small enclosed room, it is impossible to decide, by mapping the trajectory of bodies such as a dropped ball, whether the room is at rest in a gravitational field, or in free space aboard an accelerating rocket generating a force equal to gravity.[16]

Do you know about that new theory? Did you watch that documentary?  Share with me so that I can learn something new?

Saturday, August 7, 2010

Master of Ceremony

I learned from what they asked.. They asked me to become Master of Ceremony for one big event (big event for me) It was a school SpeechDay. To me, it was very appreciated for being MC, together with my otai (seniors) Pn Syhamala and Pn Airine..

It was started at 9.30 am and alhamdulillah ended earlier at 11.30 am. Me and Zainul Haris were amatur in this event. We were trained to become MC for any programmes in school. Means we might get more and more tasks as MC next time.

What I learned from this task are :
  • I need more cheerful expression. (Maybe I was nervous to see our TPM's wife as our VVIP guest)
  • I need more gorgeous dress for big event like this time (from what Pn Syhamala told me, I have to buy new blue batik dress for the next event. I don't have it now because I prefer another color for batik. So, I don't have blue batik in my collections..)
  • I must wear cork shoes! No high heel shoes..haha.. No compromies!!

Other than that was ok, good, nice voice and you are versatile! Who knows physics teacher can be MC. heks!

~Pujian Ada Makna~
From the table of MC