Questions about time

[Perpetual Student]

Time Exists, Space Does Not

Wait... What?

This was discussed some months ago HERE.

 

[The Man]

I'm the one supplying the evidence and the logic here. You aren't. Instead you're the one dismissing it.

Yes. That's how they are defined. The second is "the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom". That relates to the NIST Caesium fountain clock where hyperfine transitions emit microwaves. There's a "resonant frequency" which is said to be 9,192,631,770 Hz. To define the second we do something similar to sitting in a boat counting oncoming ocean waves bobbing us up and down. When we get to to 9,192,631,770, we say that's a second, so the frequency is 9,192,631,770 Hz by definition. Then once we've got the second we then define the metre as "the distance travelled by light in 1⁄299,792,458th of a second". That's like saying how far the waves move whilst they bob us up and down 30.66 times. Note that if the waves were to move towards us slower, our second would be bigger, but the metre is unchanged because the slower light and the bigger second cancel each other out. Also note that we use the second and metre to measure the local speed of light, so we always measure 299,792,458 m/s regardless of gravitational potential.

Here we see what is perhaps Farsight’s fundamental problem, he provides a definition of a second as “"the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom". That relates to the NIST Caesium fountain clock” and then simply chooses to ignore that deffinition to claim later “our second would be bigger” just because he thinks it suits him to do so at that time.

Let’s do some math. As a second by the definition given is “9,192,631,770 periods” a 1% “bigger” length of time would be 9,284,558,088 periods and thus not a second by the given definition. It would seem Farsights intent on providing that definition is simply so he can ignore it just to claim whatever he wants like “our second would be bigger” whenever it suits him.

What use is a definition you deliberately ignore Farsight, other than simply to demonstrate that your ignorance is, well, deliberate?

 

[Johnny Brant]

Sorry if this has already been answered, but what is the definition of time?

 

[Farsight]

Here we see what is perhaps Farsight’s fundamental problem, he provides a definition of a second as “"the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom". That relates to the NIST Caesium fountain clock” and then simply chooses to ignore that deffinition to claim later “our second would be bigger” just because he thinks it suits him to do so at that time.

I'm not ignoring anything. You are. I gave a rowboat analogy. Waves come at you, and count how many times the boat bobs up and down. If the waves are coming at you slower, the same count gives you your bigger second.

Let’s do some math. As a second by the definition given is “9,192,631,770 periods” a 1% “bigger” length of time would be 9,284,558,088 periods and thus not a second by the given definition. It would seem Farsights intent on providing that definition is simply so he can ignore it just to claim whatever he wants like “our second would be bigger” whenever it suits him.

See above. Don't ignore it.

What use is a definition you deliberately ignore Farsight, other than simply to demonstrate that your ignorance is, well, deliberate?

Pot. Kettle.

 

[Farsight]

if that is referring to Godels model of the universe using the Einstein field equations then it is not really relevent as that only applies to a particular universe which demonstrably does NOT have the "rotation" properties our one has. It just is useful as a POSSIBLE solution to the field equations.

It's relevant in that it's telling you something about what Einstein and his buddy thought about time in 1949.

"People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion." - Albert Einstein

"The only reason for time is so that everything doesn't happen at once." - Albert Einstein

http://www.alberteinsteinsite.com/quotes/einsteinquotes.html

Not very convincing.

Paraphrased and interpreted at:

http://discovermagazine.com/2002/mar/featgodel

Einstein's claim is more subtle. He suggests that change is an illusion. Things do not become, they have not been, and they will not be: They simply are. Time is like space;

This is an airbrushed version that contradicts Godel's conclusion, which Einstein's agreed with. See A World without Time. Instead of demonstrating the possibility of time travel, Godel worked out that you just couldn't do it.

 

[DazzaD]

This is an airbrushed version that contradicts Godel's conclusion, which Einstein's agreed with. See A World without Time. Instead of demonstrating the possibility of time travel, Godel worked out that you just couldn't do it.

without reading the book does it refer to godels cosmological model?

 

[The Man]

I'm not ignoring anything. You are. I gave a rowboat analogy. Waves come at you, and count how many times the boat bobs up and down. If the waves are coming at you slower, the same count gives you your bigger second.

You are again specifically and deliberately ignoring the definition, giving a quantified definition of a second, in favor of your “analogy” that evidently invokes some unknown or as yet un-presented definition of a second so you can just try to claim that “if the waves were to move towards us slower, our second would be bigger”. The definition given makes no reference to the speed of the “waves” just how many constitute a second.

See above. Don't ignore it.

I haven’t and you’ve simply ignored the definition again to assert, apparently just by analogy, some undefined measure of a second that gets “bigger” than a, well, second by the given deffinition.

Pot. Kettle.

So you can’t or simply won’t answer the question? Let me try to make this simple for you. You have given a definition of a second that relates it to a spcific number of cycles from a specific atomic transition. Then you just want to claim that those cycles are or might be going “slower” (less cycles per second). Since the number of cycles per second is specifically defined you can’t have fewer cycles per second unless you just ignore the given definition, which you keep doing repeatedly. Again this seems to be your fundamental problem, you simply want to ignore a quantitative definition of a second that you are evidently aware of in favor of what I can only guess you feel is some intuitive concept (by analogy) of something going “slower”.

 

[xtifr]

You are again specifically and deliberately ignoring the definition, giving a quantified definition of a second, in favor of your “analogy” that evidently invokes some unknown or as yet un-presented definition of a second so you can just try to claim that “if the waves were to move towards us slower, our second would be bigger”. The definition given makes no reference to the speed of the “waves” just how many constitute a second.

I don't think you understand. The analogies are what matter. The math is just an approximation, intended to give mathematicians an idea of how the analogy works. This is why you really don't need any math beyond some basic high-school algebra to completely understand relativity!

That's why anyone can sit in their armchair and ignore all math, logic, and experimental evidence, and totally intuit the universe! It doesn't matter that there were three defenders covering the receiver like a blanket, or that three other guys were in the process of tackling the quarterback. He still should have been able to throw the ball forty yards down the field to hit the one dime-sized spot where the catch could have been made! Anyone could do it! Or maybe I'm confusing "armchair quarterback" with "armchair physicist"...

 

[epepke]

I don't think you understand. The analogies are what matter. The math is just an approximation, intended to give mathematicians an idea of how the analogy works. This is why you really don't need any math beyond some basic high-school algebra to completely understand relativity!

Special relativity.

 

[Farsight]

without reading the book does it refer to godels cosmological model?

Yes. Try doing a search-inside. There's 4 results for cosmological model and 13 for rotating universe. It's worth reading.

What I find amazing is the way Godel's conclusion has been corrupted. It's a bit like Schrodingers cat I suppose.

 

[Tubbythin]

Treat one side of the angled path as a right-angled triangle and the hypotenuse is the lightpath where c=1 in natural units, the base is the speed v as a fraction of c, and the height gives the Lorentz factor γ = 1/√(1-v²/c²). If the moving mirror is going at .99c the Lorentz factor is 1/√(1-0.99²/1²) = 1/√(1-0.98) = 1/√0.2 = 1/0.142 = 7. So there's a sevenfold time dilation.

Again? v²/c² is unitless. So long as v and c have the same units it does not matter what system of units you use. How many times do you have to be told this before you stop repeating this nonsense about natural units?

 

[The Man]

I don't think you understand. The analogies are what matter. The math is just an approximation, intended to give mathematicians an idea of how the analogy works. This is why you really don't need any math beyond some basic high-school algebra to completely understand relativity!

That's why anyone can sit in their armchair and ignore all math, logic, and experimental evidence, and totally intuit the universe! It doesn't matter that there were three defenders covering the receiver like a blanket, or that three other guys were in the process of tackling the quarterback. He still should have been able to throw the ball forty yards down the field to hit the one dime-sized spot where the catch could have been made! Anyone could do it! Or maybe I'm confusing "armchair quarterback" with "armchair physicist"...

Unfortunately, xtifr, I understand the inclination all too well and as "armchair quarterback" is quite analogous to "armchair physicist" that’s all that really matters ain’t it.

 

[DazzaD]

Yes. Try doing a search-inside. There's 4 results for cosmological model and 13 for rotating universe. It's worth reading.

What I find amazing is the way Godel's conclusion has been corrupted. It's a bit like Schrodingers cat I suppose.

but then surely my previous comment applies...

Godel's conclusions about time travel only applied to his model universe which was demonstrably shown NOT to match with our observable universe

"is it rotating yet?" ... no...

 

[Farsight]

Read the book. His conclusion was that time isn't something that "passes", and that time travel is a no-no. And yet his conclusion has been corrupted into "Godel demonstrated the possibility of time travel". It's just like Schrodinger's cat. Schrodinger proposed his thought experiment to show just how silly the Copenhagen interpretation is, and yet it's now touted as a demonstration of quantum weirdness and the multiverse.

 

[Farsight]

I don't think you understand. The analogies are what matter. The math is just an approximation, intended to give mathematicians an idea of how the analogy works. This is why you really don't need any math beyond some basic high-school algebra to completely understand relativity!

It's not the analogies that matter, xtifr, it's understanding that matters. And the maths such as the Pythagoras' theorem in Simple inference of time dilation due to relative velocity helps to deliver the understanding. It helps you to understand that it's light moving between those parallel mirrors, not time flowing, and that the invariant Lorentz interval is there because light-path lengths are the same. Analogies help your understanding too, like the submarine scenario in The Other Meaning of Special Relativity by Robert Close. This talks about the wave nature of matter, and how when you're made of waves you always measure wave speed to be the same. When you change your speed or move to a place where the waves go faster or slower, you don't measure them going faster or slower. It's all so simple, and yet for some strange reason some people would rather cling to axiom and mystery than gain understanding.

 

[Kwalish Kid]

It's not the analogies that matter, xtifr, it's understanding that matters. And the maths such as the Pythagoras' theorem in Simple inference of time dilation due to relative velocity helps to deliver the understanding. It helps you to understand that it's light moving between those parallel mirrors, not time flowing, and that the invariant Lorentz interval is there because light-path lengths are the same. Analogies help your understanding too, like the submarine scenario in The Other Meaning of Special Relativity by Robert Close. This talks about the wave nature of matter, and how when you're made of waves you always measure wave speed to be the same. When you change your speed or move to a place where the waves go faster or slower, you don't measure them going faster or slower. It's all so simple, and yet for some strange reason some people would rather cling to axiom and mystery than gain understanding.

You mean the people that talk about this stuff for years but never bother to learn the actual physics?

Given that you cannot actually do any of this physics, don't you feel embarrassed to be pretending to be explaining it?

Don't you feel embarrassed to be resting claims on Robert Close? This is a guy that really seems to be mentally ill.

 

[W.D.Clinger]

My highlighting:

Read the book. His conclusion was that time isn't something that "passes", and that time travel is a no-no. And yet his conclusion has been corrupted into "Godel demonstrated the possibility of time travel". It's just like Schrodinger's cat. Schrodinger proposed his thought experiment to show just how silly the Copenhagen interpretation is, and yet it's now touted as a demonstration of quantum weirdness and the multiverse.

I've got a better idea: Let's read what Gödel himself wrote.

...it is theoretically possible in these worlds to travel into the past, or otherwise influence the past.

That's Gödel's own summary of property (6), in the first section (titled "The Main Properties of the New Solution"), in

Kurt Gödel. An example of a new type of cosmological solutions of Einstein's field equations of gravitation. Reviews of Modern Physics 21(3), July 1949, pages 447-450. Online at
http://link.aps.org/doi/10.1103/RevModPhys.21.447
​

Although it's conceivable that Gödel came up with his solution and proved it has the nine properties described in that first section only because Gödel wished to argue that "time travel is a no-no", that is not the impression I get from Gödel's final section, and it is certainly not the impression that's created by Gödel's final paragraph:

....Assuming galactical systems were formed by condensation of matter originally distributed uniformly...one obtains...for the average period of rotation of galactic systems 5 * 10⁴ years. This number is of the correct order of magnitude....Of course such comparison with observation has very little significance before an expansion has been combined with the rotation....The radius of the smallest time-like circles, in the solution given in this paper, is of the same order of magnitude as the world radius in Einstein's static universe.

That is how Gödel's paper ends. I look forward to seeing Farsight explain why he thinks Gödel was arguing against even the theoretical possibility of time travel.

 

[The Man]

Sorry if this has already been answered, but what is the definition of time?

Sorry, Johnny Brant, I meant to directly address your question before. As cited by Farsight before the standard quantitative definition of time (a second) is given by the Electromagnetic emissions required to induce a specific atomic state transition. Other than that, one can define time as the dimensional displacement between events that can occur at the same spatial coordinates (Farsight's purportedly analogous "boat"). I hope this helps.



Oh and when I said before that " The definition given makes no reference to the speed of the “waves” just how many constitute a second." that wasn't entirely accurate. As cycles per second that quantitative definition of a second also defines the angular frequency of that incident EM wave (the number of cycles times 2pi). So that particular "speed" (angular speed, the "speed" of the displacement of Farsight's "boat" in his analogy) does not vary by that given definition. The very point I've been trying to make. I apologies for that misstatement.

 

[xtifr]

It's not the analogies that matter, xtifr, it's understanding that matters.

Oh, non sequitors, where would we be without you?

And the maths such as the Pythagoras' theorem ...

Oh, that's right. I forgot. Einstein only tried to mislead us with his advanced math. The mundane, high-school math is all fine. It's only when you get to the calculus and beyond that you need to start ignoring the actual math that Einstein wrote and stick to the analogies to arrive at a true understanding. I mean, it's not really possible to describe relativity in terms of calculus, is it? Or at least, so I assume, since the one person ever to discover the true meaning of relativity refuses to perform any calculus or answer any questions involving calculus or anything more complex.

 

[Farsight]

I give you the maths and the analogy and the understanding for SR and the time dilation due to relative motion, and now you're changing the goalposts to GR? What's the matter with you? Don't you want to understand? Would you rather cling to woo like time travel? Besides, if you want to understand GR, you've got to read what Einstein said about the motion of light:

1911: If we call the velocity of light at the origin of co-ordinates cₒ, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = cₒ(1 + Φ/c²)
1912 : On the other hand I am of the view that the principle of the constancy of the velocity of light can be maintained only insofar as one restricts oneself to spatio-temporal regions of constant gravitational potential.
1913: I arrived at the result that the velocity of light is not to be regarded as independent of the gravitational potential. Thus the principle of the constancy of the velocity of light is incompatible with the equivalence hypothesis.
1915: the writer of these lines is of the opinion that the theory of relativity is still in need of generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned.

Note that he said all this in German, and he didn't use the word velocity. The word he used was geschwindigkeit. That's speed. And c is a speed, not a velocity. The principle was the constant speed of light, not the vector-quantity. It isn't time that goes slower in a gravitational field, it's light. Einstein spelled it out. But doubtless your next will post will say it doesn't matter what Einstein said. And you will hide your lack of understanding behind maths like some religious groupie hides behind Latin because he wants to believe in woo.