Home » Posts tagged 'clock'

Tag Archives: clock

Is time always a measurement of movement of matter

Is the oscillation of energy levels of caesium in atomic clocks a form of motion (i. e. is time always a measurement of movement of matter)?

asked Gary Wederspahn


The Oscillations in cesium clock is not mechanical. the radiation emission frequency between the two hyperfine levels of the atom is used as the standard for measuring time. Due to the fact that the standardisation of time is based on radiations, the atomic clocks are also called radio clocks.

Caesium clocks are the most accurate commercially produced time and frequency standards, and serve as the primary standard for the definition of the second in SI (the metric system). By definition, radiation produced by the transition between the two hyperfine ground states of caesium (in the absence of external influences such as the Earth’s magnetic field) has a frequency of exactly 9,192,631,770 Hz. That value was chosen so that the caesium second equalled, to the limit of human measuring ability in 1960 when it was adopted,

Very accurate clocks can be constructed by locking an electronic oscillator to the frequency of an atomic transition. The frequencies associated with such transitions are so reproducible that the definition of the second is now tied to the frequency associated with a transition in cesium-133:

1 second = 9,192, 631,770 cycles of the standard Cs-133 transition

Cs Atomic clock
Cs Atomic clock

Ref http://hyperphysics.phy-astr.gsu.edu/hbase/acloc.html#c2

The oscillation in an atomic clock is between the nucleus of an atom and the surrounding electrons. This oscillation is not exactly a parallel to the balance wheel and hairspring of a clockwork watch, but the fact is that both use oscillations to keep track of passing time. The oscillation frequencies within the atom are determined by the mass of the nucleus and the gravity and electrostatic “spring” between the positive charge on the nucleus and the electron cloud surrounding it.

Ref: http://web.mit.edu/scicom/www/atomicclock.html



Relativity, Black Hole and some doubts

In the model of the big bang I would like to pose the following question. My understanding is that

1. The expansion of the universe is accelerating and

2. The radiation or shock wave to keep the analogy going is something we can measure.

My question is this. While we can rewind the clock to a single moment when the universe was infinity dense how do we know that this was a moment at all. Let me elaborate. As the universe expands could time or space time not also expand and if so than when the big bang occurred is something we cannot measure merely by rewinding the clock. If we are experiencing time at a given rate when the universe is at its current size would time not be being effected by the expansion also and if so would that mean the there was simply no start and no end to the universe? Perhaps the big bang is not as accurate as we may wish and perhaps it is our ability to comprehend that is limited. I propose there is no start or end to the universe it has always and will always be as it, and we, cannot exist without time and as such these two objects or things form a symbiotic relationship with each other. While the universe expands so does time and its effects are reduced in line with its expansion. Does this sound plausible and if not why?

Question from Thermal Properties of matter

A clock has a pendulum made of brass . The clock record time correctly at 20 degree C. If temp is increased by 10 degree C, the clock will gain or lose time and by how much??? (Shubham Chauhan posted this question)

String Theory and Einstein

S.A. JEFFREY asks: “My clock converts a circular earth orbit into an eliptical one.
And the result is six minutes difference from sidereal time per year.
Approx we take this figure to 10,000 digits of pi accuracy as the formula uses Pi.
A cicular orbit can be in as many as 11 dimensions but these are unstable when an orbit is converted to an elipse it becomes stable in three dimensions plus one of time.
Thus you can reverse the equation to convert Einsteins 4D space time to 11 dimensions.
So you can convert String theory to Einsteins thoery and EInsteins theory back into string theory.
Some scientists believe Einsteins thoery cannot be expressed in 10 dimensions.
Others believe EInsteins thoery can be expressed in as many dimensions as you want to use……………….

What do you believe can my thoery work to unify Einsteins thoery and string theory.
And is my clock time more accurate or just an error of six minutes per year rather than a more accurate measurement of time……………………..…………….

Please help me with this problem.

I am not answering the question myself what I have provided is background to the problem.

The central question is whether Einsteins 4D space/time can be converted to ten dimensions or not.”

A Question From Relativity

Sreeram Asks:

“my question is on relativity.Let us say two persons,one is standing still and other is moving with uniform velocity in a straight line(in +ve x direction),both are carrying  a clock synchronized previously.For the moving person he is at rest and the other guy is moving away from him in the opposite direction(negative x direction).Both of them feel that clock of the other guy is moving slowly.let us say the moving guy never stops and he calls the other in telephone at some point of time and asks the
time in his clock.But he will find that clock with him,is actually faster.how can that happen?”


Please note that the theory of relativity can  be applied only for velocities compared to that of light in vacuum (3 lakh km/s). The situation will be very much different when we travel at such velocities. So far we are able to accelerate only subatomic particles to this speeds (LHC).



Visitors So Far @ AskPhysics

  • 2,043,857 hits

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join 3,931 other subscribers


%d bloggers like this: