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An odd question about times.

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  • User profile image
    Secret​Software

    How fast is time? Can we calculate the rate of change of time? Has time became faster in the last 3.4 million years?

    I tried to measure the speed of time in terms of earth rotations around itself and around the sun. If the earth started to rotate faster around itself and around the sun, does that mean that time rate of change between two distinct occurances has actually increased? (Shorter days and nights?)

    I know its abit of an odd question , but I wish to find a way to know how fast time is passing by mathimatically.

  • User profile image
    Bas

    SecretSoftware wrote:
    How fast is time? Can we calculate the rate of change of time? Has time became faster in the last 3.4 million years?

    I tried to measure the speed of time in terms of earth rotations around itself and around the sun.


    My guess is that, roughly, time has a speed of about 1s/s. In terms of rotations, about 24 hours per earth rotation, and 365,25 days per sun rotation.

  • User profile image
    PaoloM

    Time, in a relativistic universe, in subject only to variation in the speed of light. The conventions we use to calculate time (earth rotations and revolutions) can change - and do - over time, but the actual intervals, as you could measure by monitoring radioactive elements' decays, are pretty much immutable.

  • User profile image
    JohnAskew

    wikipedia wrote:
    Since 1967, the International System of Units (SI) has defined the second as 9,192,631,770 cycles of the radiation which corresponds to the transition between two energy levels of the ground state of the Caesium-133 atom.



    Time is relative.   heheehahaha.

    Time is what you make of it....

    (enter Austin Powers with inane play on words - till he gets sick of it)

    Time is money...

    Who has time to spare...


    I don't know how you'd want to formulate a mathematical expression of time.

  • User profile image
    Sven Groot

    If the rotation of the earth changed, that would not cause time to change. Days would be shorter, but a second is not defined in terms of the length of a terrestrial day. Currently a second is defined in terms of the radiation periods of a caesium atom (see here).

    And although movement affects time in accordance with special relativity, the Earth would have to speed up or slow down enormously for there to be any measurable effect.

  • User profile image
    Ping

    SecretSoftware wrote:
    How fast is time? Can we calculate the rate of change of time?


    According to the Relativety theory of Einstein, If we travel the same speed as light, the time will stop, if we travel faster than the light, the time will goes back,
    The speed of light is 3*108(i.e 300000000) m/s in vacuum condition, that's about the speed of time I think.
    Whereas
    GMm/R2 = 1/2 mv2 =mg

    v=gR1/2

    This is the escape velocity if you on the earth, (R=radius of earth)
    So if u reaches over this speed, you will be throw out of atmosphere.
    No one can reaches the speed of light.
    Ping Shen

  • User profile image
    W3bbo

    Ping wrote:
    
    SecretSoftware wrote:How fast is time? Can we calculate the rate of change of time?


    According to the Relativety theory of Einstein, If we travel the same speed as light, the time will stop, if we travel faster than the light, the time will goes back


    That's conjecture, it's never been proven (obviously).

  • User profile image
    jsampsonPC

    W3bbo wrote:
    
    Ping wrote:
    SecretSoftware wrote:How fast is time? Can we calculate the rate of change of time?


    According to the Relativety theory of Einstein, If we travel the same speed as light, the time will stop, if we travel faster than the light, the time will goes back


    That's conjecture, it's never been proven (obviously).


    Time going backwards? Uh, I don't think so. I don't think I could ever watch a broken mug repair in mid air, and float up to the top of a shelf, placing itself neatly in the path of a rolling baseball.

    But, the cool thing is about Gravity, and Time Dilation. That the force of gravity effects how fast time occurs, relatively speaking of course. People like Humphrey's and Hawking have written awesome stuff on this.

    If you could rest near the event-horizon of a black hole time would practically stop....according to your spectators...but to you, time for them would be buzzing at an obnoxiously fast pace...until they all die of course Smiley

  • User profile image
    JohnAskew

    I prefer the idea that the "big bang" is complemented with it opposition (Ctrl-Z?), whether that means time-reversal or just time/space-recycling ~the central black hole takes all in~. It's a matter of aesthetics for me... In my limited capacity for deep thinking the only other option would be that the big bang just runs out of fuel and all comes to a stop. Not inifite enough for me. I'm hard to please.
    Big Smile

  • User profile image
    Sven Groot

    Ping wrote:
    According to the Relativety theory of Einstein, If we travel the same speed as light, the time will stop, if we travel faster than the light, the time will goes back

    Actually the lorentz transformation which allows you to calculate time dilation has no value when you travel the speed of light. Although the function has a limit at infinity (that is, time dilation approaches infinity as you approach the speed of light), the value of the function at the speed of light is undefined.

    Furthermore, mass is affected similar to time, so as you approach c, you mass will also approach infinity. Thanks to Newton's simple first law (F=ma), this means that reaching the speed of light will require infinite force and thus infinite energy. This has in fact been observed in particle accelerators.

    In other words, it can't be done.

    It is generally accepted that special and general relativity are accurate descriptions of these effects while you travel below light speed. What happens at light speed and beyond (if this is even possible at all, which I doubt) is something we'll likely never know and it's unknown whether the Lorentz transformation still accurately describes the situation in those circumstances.

  • User profile image
    Sven Groot

    JohnAskew wrote:
    I prefer the idea that the "big bang" is complemented with it opposition (Ctrl-Z?), whether that means time-reversal or just time/space-recycling ~the central black hole takes all in~. It's a matter of aesthetics for me... In my limited capacity for deep thinking the only other option would be that the big bang just runs out of fuel and all comes to a stop. Not inifite enough for me. I'm hard to please.

    Have you been watching Red Dwarf? Tongue Out

  • User profile image
    vesuvius

    In some ways I hate getting roped into questions like this (but cannot resist it) as they are relative to the perception of the subject. The stuff that gets taught in school is what I shall elucidate upon, thus precluding the personal view. To resolve your question, I will introduce a definition of "relativity" from the compact version of the Oxford Dictionary.

     • noun 1 the absence of standards of absolute and universal application. 2 Physics a description of matter, energy, space, and time according to Einstein’s theories based on the importance of relative motion and the principle that the speed of light is constant for all observers.


    In a nutshell, time is NOT a constant, "The Speed of light is!".

    That is the answer to your question.

    When you look at the Moon or Jupiter you do not see it / them  as 20:58 GMT  (the time now presently here in England), but as the time the light has taken to travel from either celestial bodies. Time merely helps us all to get to work at the same time, or attack enemy x at time y. any celestial body outside the solar system has a different time-frame as the sun is no longer it's determinant.

    I like to think of Douglas Adams's Hitchhikers Guide to the Galaxy!

  • User profile image
    Cannot​Resolve​Symbol

    JohnAskew wrote:
    I prefer the idea that the "big bang" is complemented with it opposition (Ctrl-Z?), whether that means time-reversal or just time/space-recycling ~the central black hole takes all in~. It's a matter of aesthetics for me... In my limited capacity for deep thinking the only other option would be that the big bang just runs out of fuel and all comes to a stop. Not inifite enough for me. I'm hard to please.


    A gnab gib?  Tongue Out

  • User profile image
    Matthew van Eerde

    The discrepancy between absolute time (cesium atoms) and solar time (Earth going around the sun) can be, and is being, measured.  See Leap Second.

  • User profile image
    JohnAskew

    What about the "spooky action at a distance"? Where sub-atomic particles seemingly traverse the space/time continuum without a linear path? Could that be considered faster than the speed of light?

    :O

    What is Red Dwarf? I do watch the Discovery channel often...

    "Gnab Gib". That works.

  • User profile image
    vesuvius

    My dear chap, forget the abstruse realm of equations whose "fields" most normal people have no clue about, just have a closer look at the ubiquitous E=MC2 equation. Energy = (The mass of the object) multiplied by (The speed of light squared). Rearrange the equation.

    The reason that you cannot reach the speed of light is because you become heavier and heavier and heavier the faster you go. In fact the closer you get to the speed of light, the closer you approach infinite density. This means that you require infinite energy which is what we (unfortunately) do not have.

    That is the conundrum!

  • User profile image
    PaoloM

    vesuvius wrote:
    I like to think of Douglas Adams's Hitchhikers Guide to the Galaxy!

    Lunch time as a double illusion? Smiley

  • User profile image
    Sven Groot

    JohnAskew wrote:
    What is Red Dwarf? I do watch the Discovery channel often...

    It's a comedy Sci-Fi show from the BBC. They had this great episode called "Backwards" which touches on what you said. It's on YouTube (don't bother trying to read the text at the beginning, it's largely irrelevant).

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