You are saying that distance and time are one and the same thing. This can certainly be arranged by adopting a suitable unit system.
We could regard the speed of light, c, to be a natural unit of speed which can be given the value 1.
If we then look at the equation distance = c x time, when c is made equal to 1, distance becomes equal to time.
Your spat appears to be with one person in particular.
I'm staying well out of it, as I am not an engineer!
So...
The 9192631770 cycles of frequency -- really is -- the definition of one second of time!
In order to know what 1 second is, you have to count the 9192631770 cycles. Then you have 1s duration.
The time on a plastic watch is just a convenience, not to be taken seriously, same as a ruler for measuring length.
No wanking involved.
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Of course, @Bonsai, when we say that 'space' is expanding, we really mean that 'spacetime' is expanding and that's not explainable in terms of people's everyday experience of time, distance and geometry.
In spacetime, 3D Euclidian geometry does not apply. Instead we use Riemannian geometry in which time is regarded as a spacetime distance.
It was Riemannian geometry that provided Einstein with a mathematical basis for his general theory of relativity.
In spacetime, 3D Euclidian geometry does not apply. Instead we use Riemannian geometry in which time is regarded as a spacetime distance.
It was Riemannian geometry that provided Einstein with a mathematical basis for his general theory of relativity.
Oh I know.
I am still unconvinced that time is not a principal parameter of the universe. Every aspect of an electronic circuit is affected by time - frequency, filter calculations, even calculating the heat generated by a circuit is dependent on time.
Show me how to design an analog filter without time and I will be convinced. That means NO time dependent variables; NO frequency, NO capacitance or inductance, etc.
I hope this illustrate how silly it is to dismiss time as a basic parameter of the universe. The very concept of a frequency without referencing time is meaningless; same with capacitance,and inductance. The very concept of an analog filter without frequency is ludicrous. So SHOW ME.
But that's my bias as an engineer. I really want to be shown that I'm wrong. Then I will have really learned something!
Over on NASA's Hubblesite, I read that 30 years of the space telescope's measurements of the cosmic expansion rate can be used to predict that the Universe will double in size in 10 billion years.
https://hubblesite.org/contents/news-releases/2022/news-2022-005
Hubble looks at supernovae to measure the expansion rate of 73 which is greater than the cosmic microwave background measure of 67.
https://hubblesite.org/contents/news-releases/2022/news-2022-005
Hubble looks at supernovae to measure the expansion rate of 73 which is greater than the cosmic microwave background measure of 67.
It simply doesn’t have to be fundamental to the entire universe to work as a fundamental here. In our neck of the woods, Newtonian mechanics works perfectly well, even though incomplete. You fall at 32 ft per second squared and you can calculate the result.
I dont care if the rate is different somewhere else millions of light years away. I care about the ground.
I dont care if the rate is different somewhere else millions of light years away. I care about the ground.
Attachments
To my mind time is fundamental to the way the universe works. Without it there is no causality, no before, present and after. Without time, how does energy dissipate? How does a logic circuit work where events have to take place in sequence?
Even though Einstein pondered on illusory nature of time, it remains deeply embedded in SR and as space time in GR.
Even though Einstein pondered on illusory nature of time, it remains deeply embedded in SR and as space time in GR.
But you would wonder about the effect of gravity. The usual eg that gets mentioned
How does this connect with General Relativity and GPS? As predicted by Einstein's theory, clocks under the force of gravity run at a slower rate than clocks viewed from a distant region experiencing weaker gravity. This means that clocks on Earth observed from orbiting satellites run at a slower rate
That requires a correction to be applied. So time can't be defined without defining gravity??
Using GPS and a microwave ranging system, the GRACE system measures changes in the speed and distance between the two satellites which in turn reflects changes in the gravitational pull of the Earth. The result is a highly accurate and detailed map of Earth's gravity anomalies.
This effect is called time dilation. The faster you travel through space, the slower you travel through time. This is another way of saying you can never travel faster than the speed of light as the clock would stop altogether.
A weak effect in practice but in relationship to the universe we are moving in a number of directions not just down to the plant's rotation.
Complex numbers
https://www.varsitytutors.com/hotmath/hotmath_help/topics/polar-form-of-a-complex-number
The polar form may be gain and phase - that can be expressed in complex form. Sums done and then transformed back to polar.
I meant, AjohnL, I was staying out of the time versus frequency argument.
To extend your argument, a photon which travels at the speed of light has no movement in time. From a photon's perspective it will cross the Universe in zero time, i.e., instantaneously.
To extend your argument, a photon which travels at the speed of light has no movement in time. From a photon's perspective it will cross the Universe in zero time, i.e., instantaneously.
Galu have you watched Dr. PhysicsA on YouTube? He does a fantastic 2-hour lecture on the derivation of the GR equations - with acknowledgments to Leonard Susskind
Part 1:
If you haven't seen Leonard Susskind's lecture in post #2105, you've really missed something.
I shall attempt to watch those lengthy lectures at a later date.
I'm occupied at the moment as my wife is giving me a lecture! 😉
I'm occupied at the moment as my wife is giving me a lecture! 😉
There has to be different expansions. Otherwise we would have found an apple size atom somewhere in universe. Expansion of universe is actually very hard to swallow fact. It doesn't make any sense.
"The views of space and time which I wish to lay before you have sprung from the soil of experimental physics, and therein lies their strength. They are radical. Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality." - Hermann Minkowski (Einstein’s former teacher) in 1908
Yes indeed, the expansion of spacetime is not explainable in terms of people's everyday experience of time, distance and geometry.
I'm not sure I follow you there. Perhaps you need to rephrase it? The space inside an atom does not expand with the Universe.
Those of us who follow the Standard Model of Physics do not worry too much about Gravity and Time:
And String Theory is frankly ludicrous. Does anyone believe in hidden dimensions? I know I don't. 4D is it!
All you need to know is that U(1) X SU(2) X SU(3) explains most of it.
https://en.wikipedia.org/wiki/Mathematical_formulation_of_the_Standard_Model
The degrees of Freedom are N^2 - 1.
Thus only one Electromagnetic Force, 3 X (Combined) W and Z Bosons and 8 Quark Colour charges.
Time resides in QED, IMO. But I could be wrong on this. Severely difficult Mathematics. 🙁
And String Theory is frankly ludicrous. Does anyone believe in hidden dimensions? I know I don't. 4D is it!
All you need to know is that U(1) X SU(2) X SU(3) explains most of it.
https://en.wikipedia.org/wiki/Mathematical_formulation_of_the_Standard_Model
The degrees of Freedom are N^2 - 1.
Thus only one Electromagnetic Force, 3 X (Combined) W and Z Bosons and 8 Quark Colour charges.
Time resides in QED, IMO. But I could be wrong on this. Severely difficult Mathematics. 🙁
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