1. I have read that conservation of energy is not true in absolute, if that is true, could anyone tell me a couple of instances when energy is distroyed?

2.

3. Originally Posted by logic
I have read that conservation of energy is not true in absolute, if that is true, could anyone tell me a couple of instances when energy is distroyed?
To the best of my understanding - which a proper physicist may need to correct - it goes roughly as follows:

1) the conservation of energy is a purely empirical law. In other words it appears to be true based on observation, rather than being true due to some deeper logic. But it does appear always to be obeyed.....subject to the qualification in (2) below.

2) At the macro level it is always true, but the micro level can be a little more complex. At at the level of quantum effects (sub-atomic particles and the like) you can get fluctuations, arising from the Uncertainty Principle, which imply tiny, instantaneous and temporary deviations from strict conservation. None of this means there is either any "created" energy available to "do" anything with, or any permanent "destruction of energy", though, because these tiny deviations vanish and are almost immediately counterbalanced by deviations in the opposite sense, etc. So all you have is a sort of quantum flickering, around a mean energy value that always corresponds to that expected from conservation.

4. In general — it depends on what you mean by "energy", and what you mean by "conserved".
Is Energy Conserved in General Relativity?

The precise answers will depend on what you mean by energy and what situation you consider.
The Reference Frame: Why and how energy is not conserved in cosmology

Or, to put it another way: it's complicated.

5. To add, at the macro level it need not be true either - at universal scales the laws don't actually make sense.

(Oh I see Strange beat me to it Mental note to not keep a reponse unsubmitted without checking for updates to the thread made)

6. It is well accepted principle. General Relativity creates doubt but it is not final conclusion. In general conservation of energy and mass is true principle. If it is not true at micro level it would also be false for macto leve. But at the moment is seems true.

7. In the words of Richard Feynman, "It is important to realize that in physics today, we have no knowledge what energy is. We do not have a picture that energy comes in little blobs of a definite amount."

Mass and energy are equipment, they can be converted from each other but can not be destroyed i.e. mass-energy conservate them self

How law of mass & energy conservation apply ?
Simply, every thing that exists in Space is either energy or mass
How a physical existed thing can be destroyed i.e. its existence can be finish
This is how law of mass & energy conservation is essential and works

8. Originally Posted by RAJ_K
Simply, every thing that exists in Space is either energy or mass
How a physical existed thing can be destroyed i.e. its existence can be finish
This is how law of mass & energy conservation is essential and works
You always seem very keen on arguing based on your "common sense". If you read some of the linked articles, you will see this is not necessarily accurate.

Your argument here is simply based on incredulity ("I don't believe something can cease to exist") and is not convincing.

What about redshifted photons from distant galaxies? Red-shift means lower energy. Where has that energy gone?

9. I thought the red shift was simply attributable to the motion, i.e. due to the recession of the source, the energy dissipated by photons absorbed here on Earth is reduced, in a similar way to the energy dissipated by a bullet being reduced, if the gun were receding rapidly from the target when the trigger is pulled.

But I expect you'll tell me this is too simple.......

10. Originally Posted by exchemist
I thought the red shift was simply attributable to the motion, i.e. due to the recession of the source, the energy dissipated by photons absorbed here on Earth is reduced, in a similar way to the energy dissipated by a bullet being reduced, if the gun were receding rapidly from the target when the trigger is pulled.

But I expect you'll tell me this is too simple.......
It's too simple.

You are talking about a Doppler effect (where the "loss" of energy can be accounted fro by looking at the system as a whole).

Cosmological red-shift is due to the light being emitted and received in different frames of reference (specifically, with different scale factors). Apparently, if you try and model this using Doppler shift based on the (apparent) recessional velocity, you get the wrong answer. And, I gather, there is no general way of relating energy in one frame of reference to the other. Therefore it is hard to define what "conservation of energy" would even mean. But I am skating the shores of my ignorance here...

11. Originally Posted by Strange
Originally Posted by RAJ_K
Simply, every thing that exists in Space is either energy or mass
How a physical existed thing can be destroyed i.e. its existence can be finish
This is how law of mass & energy conservation is essential and works
You always seem very keen on arguing based on your "common sense". If you read some of the linked articles, you will see this is not necessarily accurate.

Your argument here is simply based on incredulity ("I don't believe something can cease to exist") and is not convincing.

What about redshifted photons from distant galaxies? Red-shift means lower energy. Where has that energy gone?
Photon 's energy in the original reference frame is constant, but in an accelerating reference frame it is oberved different.
That s OK.This doesn't violate the principle of conservation of energy--because if there are more observer they make their measurements in different reference frames .

And who accepted it that "law of mass & energy conservation " is invalid now ?

12. Originally Posted by RAJ_K
And who accepted it that "law of mass & energy conservation " is invalid now ?
Pretty much anyone who understands the mathematics of GR, as far as I can tell.

For example, Luboš Motl (see link above) has said:
The energy conservation becomes vacuous or invalid in the general theory of relativity and especially in cosmology.
And:
Phil Gibbs is convinced that all relativists are wrong when they say that the energy conservation law is weakened, trivialized, corrected, or violated in general relativity in any way.

But they are right.
And:
Energy conservation explicitly fails in cosmology
And Sean Carroll:
Energy isn’t conserved; it changes because spacetime does.
Energy Is Not Conserved | Sean Carroll

And John Baez (see link in previous post).

13. It is error to add together energy from all observer in scaller fashion
and claim is not valid that energy is lost. Observer are not in same inertial
frame and straight forward addition of energy is not allowed.
If all
observers were instantaneously boosted by a velocity magnitude -v in the appropriate direction, it is immediately clear there was no energy lost associated with the photons that were transferred whilst the velocity difference existed. Keep in mind that energy is conserved within each reference frame, or (to put it another way) for two observers who are moving at the same speed with respect to the thing they observe.

14. Originally Posted by Strange
What about redshifted photons from distant galaxies? Red-shift means lower energy. Where has that energy gone?
Probably it is more convincing to quote the gravitational shift, Strange.
But we accept that we must accept that encergy is constantly being created in large amounts inside the atoms

15. Originally Posted by RAJ_K
It is error to add together energy from all observer in scaller fashion
No one is doing that.

Keep in mind that energy is conserved within each reference frame, or (to put it another way) for two observers who are moving at the same speed with respect to the thing they observe.
Yes, everyone agrees that conservation applies locally. It even applies between different frames of reference in flat space-time (ie. where special relativity can be used). It does not (necessarily) apply on cosmological scales.

16. Originally Posted by logic
Probably it is more convincing to quote the gravitational shift, Strange.
That is yet another souyrce of red-shift. But it is not what causes cosmological red-shift.

But we accept that we must accept that encergy is constantly being created in large amounts inside the atoms
What makes you say that? Where does that energy go? Does matter constantly get hotter? Or radiate more energy than it receives? Or continuously increase in mass?

17. Originally Posted by Strange
Originally Posted by RAJ_K
It is error to add together energy from all observer in scaller fashion
No one is doing that.

Keep in mind that energy is conserved within each reference frame, or (to put it another way) for two observers who are moving at the same speed with respect to the thing they observe.
Yes, everyone agrees that conservation applies locally. It even applies between different frames of reference in flat space-time (ie. where special relativity can be used). It does not (necessarily) apply on cosmological scales.
It also apply as assuming entire space a single unit, Mass and energy is conserved in entire space as whole .

18. Originally Posted by RAJ_K
It also apply as assuming entire space a single unit, Mass and energy is conserved in entire space as whole .
Thanks, but I'll stick with those able to prove that is not true, rather than your baseless assertions.

You have a habit of denying physics based on your imagination and how you want things to be. That is not how science works.

I have just noticed that you have added this "philosophy" to your signature: "If it doesn't make sense to me, it must be wrong." So very, very sad.

19. There is discussion of validity of law of mass and energy conservation as with time new facts arose and there is not final conclusion of doubts.
Yet is it valid and there should be no doubt.

20. Originally Posted by Strange
Originally Posted by RAJ_K
It also apply as assuming entire space a single unit, Mass and energy is conserved in entire space as whole .
Thanks, but I'll stick with those able to prove that is not true, rather than your baseless assertions.

You have a habit of denying physics based on your imagination and how you want things to be. That is not how science works.

I have just noticed that you have added this "philosophy" to your signature: "If it doesn't make sense to me, it must be wrong." So very, very sad.
Its because every existed theory that is clearly proved did surprised me and looked me very normal.

21. Originally Posted by Strange
What makes you say that? Where does that energy go? Does matter constantly get hotter? Or radiate more energy than it receives? Or continuously increase in mass?
If you accept that gravitational shift is destroying energy, you are implying theat gravity creates energy that annihilates energy.And then you must accept that electric field creates energy.

If nuclei stopped producing energy the world would collapse.
An asteroid falling on earth makes it really hot.

And you can't say it is PE. If an asteroid is rotating betwwen Mars and Jupiter , what is its PE?
If you push it toward Mars or Jupiter, it gets different energies.

22. Originally Posted by logic
If nuclei stopped producing energy the world would collapse.
Where do you get the idea that nuclei continually produce energy? Where does that energy go? Does matter constantly get hotter? Or radiate more energy than it receives? Or continuously increase in mass?

And what do your incomprehensible comments about potential energy of asteroids have to do with the nucleus?

23. [QUOTE=logic;426431]
If you accept that gravitational shift is destroying energy, you are implying theat gravity creates energy that annihilates energy.
It takes energy to destroy energy
And then you must accept that electric field creates energy too.

Moreover getting hot has nothing to do with creation of energy, you get hot on a fire, even if you are only transforming energy

24. Ah, OK, scale factors.....Thanks for the pointer...I'll need to read this up......

25. Originally Posted by logic
If you accept that gravitational shift is destroying energy
Where do you get that idea from? You appear to have a lot of basic misunderstandings of physics. Where do you get these odd ideas from?

you are implying theat gravity creates energy that annihilates energy.
Er, what? And no.

And then you must accept that electric field creates energy too.
No.

Moreover getting hot has nothing to do with creation of energy, you get hot on a fire, even if you are only transforming energy
Well you got something right, at least.

Do you want to explain why you think nuclei continually create energy? What is the evidence for that? And where that energy goes?

26. Originally Posted by Strange
You never change, Strange, presumptuous!

I was only drawing the logical consequences from your original statement : where has that energy gone!
If you are implying that gravity has destroyed the missing energy, you must accept the whole chain of random statements.

Or are you saying that it doesn't take energy to make energy disappear?

27. Originally Posted by logic
I was only drawing the logical consequences from your original statement : where has that energy gone!
If you are implying that gravity has destroyed the missing energy
I am not saying any such thing.

1. Cosmological red-shift is not the same as gravitational red shift.

2. The whole point is that in GR there is no way to define energy universally and so the whole concept of "conservation" is meaningless. (How can you conserve something if there is no way of relating energy at point A to energy at point B.)

you must accept the whole chain of [I]random statements.
I'm afraid most of your statements make little sense to me. And you are strangely reluctant to explain...

Can you explain why you think nuclei continually create energy? What is the evidence for that? And where that energy goes?

28. As someone already showed to you cosmological shift is just Doppler.
If you think in gravitational shift energy is lost you must accept the logical consequences you do not grasp (even the the asteroid: where has that energy come from?and the nuclei)
I might accept this view but I do accept the consequences
If GR is agnostic than you have a problem making statements about the issue.
If you are saying that you can destroy energy without spending energy you have a bigger problem

I'll clarify my random examples when you take a clear stance

29. Originally Posted by logic
As someone already showed to you cosmological shift is just Doppler.
No, it isn't.

If you think in gravitational shift energy is lost
I don't. Why do you keep saying that?

even the the asteroid: where has that energy come from?
I assume you are talking about potential energy being turned into kinetic energy which is then turned into heat? That has nothing to do with the creation of energy (as you yourself said).

and the nuclei
What about the nucleus? Why do you think it continually generates energy? And where does that energy go? Why are you unable to explain? Is it because it is not true?

If GR is agnostic
What does that mean? I assume English is not your native language. I am struggling to make sense of most of your statements.

30. Originally Posted by Strange
What about redshifted photons from distant galaxies? Red-shift means lower energy. Where has that energy gone?
All right, Strange, I'll rewind the tape, assume I am the one who is not articulate, now :
what does that mean, where has that energy gone ?

31. Originally Posted by logic
Originally Posted by Strange
What about redshifted photons from distant galaxies? Red-shift means lower energy. Where has that energy gone?
All right, Strange, I'll rewind the tape, assume I am the one who is not articulate, now :
what does that mean, where has that energy gone ?
The whole point is that in GR there is no way to define energy universally and so the energy hasn't "gone" anywhere. The energy measured where the photon was emitted is different from the energy measured at the point it is received. There is no way of comparing the energy at the two locations. For a more detailed answer, you will need to read one or more of the articles linked in posts 3 or 11.

32. I simply would like to know what you intended by that!
I understood that energy has disappeared, was I wrong?
If I was right, what made energy disappear? and, can it be anything different from energy?

33. Originally Posted by logic
I simply would like to know what you intended by that!
I understood that energy has disappeared, was I wrong?
If I was right, what made energy disappear? and, can it be anything different from energy?
The Reference Frame: Why and how energy is not conserved in cosmology

General relativity allows the space and time to get curved. So it is no longer the case that the objects are moving in a translationally invariant background. Most backgrounds are not translationally invariant. That's a reason why Noether's argument fails in its simplest form.

For example, you may study the evolution of particles and fields - including electromagnetic fields - in the background of an expanding cosmology. I mean the Big Bang cosmology. Because the history of the Big Bang is not invariant under translations in time, Noether's theorem tells you that the energy of the objects will not be conserved in general.

And indeed, you can check that it's not conserved. For example, photons with wavelength "L" and energy "E" become photons with wavelength "K.L" and energy "E/K" if the Universe expands by a factor of "K". It can't be otherwise: note that the number of "peaks" of the wave arranged along the visible Universe can't change - e.g. because of a "Z_K" symmetry - so the wavelength has to grow proportionally. And the photon's energy is inversely proportional to the wavelength.

So the energy of radiation will go down as "1/K".
OK?

34. Originally Posted by Strange
Originally Posted by RAJ_K
It also apply as assuming entire space a single unit, Mass and energy is conserved in entire space as whole .
Thanks, but I'll stick with those able to prove that is not true, rather than your baseless assertions.

You have a habit of denying physics based on your imagination and how you want things to be. That is not how science works.

I have just noticed that you have added this "philosophy" to your signature: "If it doesn't make sense to me, it must be wrong." So very, very sad.
Are you saying redshift of photon breaks the law of mass & energy conservation ?
It is clear redshift of photon does not breaks law of mass & energy conservation
Energy photon is saved for each reference frame no matter each may measure different energy value but
will remain same for each reference frame.

35. Originally Posted by RAJ_K
Are you saying redshift of photon breaks the law of mass & energy conservation ?
See post #33.

It is clear redshift of photon does not breaks law of mass & energy conservation
It is clear that, in the case of cosmological red shift, you are wrong.

36. Originally Posted by exchemist
Originally Posted by logic
I have read that conservation of energy is not true in absolute, if that is true, could anyone tell me a couple of instances when energy is distroyed?
To the best of my understanding - which a proper physicist may need to correct - it goes roughly as follows:

1) the conservation of energy is a purely empirical law.
Not quite. It did start as a generalization of observations (as most other "laws"), but it now has a much deeper basis, thanks to the work of Emmy Noether (a contemporary of Einstein). She showed that certain symmetries imply, and are implied by, conservation laws. Time-symmetry implies energy conservation; position-symmetry implies momentum conservation; and rotational symmetry implies angular momentum conservation. So there are now other ways to check on these various conservation laws. For example, if experiments in particle accelerators were to show violations in any of these symmetries, we would know that the corresponding conservation laws don't always hold.

37. Originally Posted by logic
I simply would like to know what you intended by that!
I understood that energy has disappeared, was I wrong?
Energy has disappeared.

If I was right, what made energy disappear? and, can it be anything different from energy?
The metric expansion of space made the energy disappear.

38. Originally Posted by Strange
Originally Posted by RAJ_K
Are you saying redshift of photon breaks the law of mass & energy conservation ?
See post #33.

It is clear redshift of photon does not breaks law of mass & energy conservation
It is clear that, in the case of cosmological red shift, you are wrong.
Yes Law of conservation of mass and energy does not apply what we observe about cosmological red shifting of photon but yet we have to see it detail what is matter behind it, there is no final conclusion its start , matter is not yet clear enough

39. Originally Posted by Strange
The metric expansion of space made the energy disappear.
What proof is there of that?

40. Originally Posted by logic
Originally Posted by Strange
The metric expansion of space made the energy disappear.
What proof is there of that?
"Proof"? What an odd question. This is science.

Anyway, this is what is described by relativity, which is an extremely well tested theory. About as close to "proof" as you get in science. See posts #3 and #33.

41. Originally Posted by Strange
"Proof"? What an odd question. This is science.
.
That is indeed a very odd answer, you have a very peculiar idea of science.

42. I'm getting a bit suspicious of Logic.
In his other thread, he's dropping some hints that he's got a pet hypothesis in cosmology to spell out what he thinks is Expansion.

He's also hinting at bordering on Tired Light... but going about it another way.
Originally Posted by logic
]you have a very peculiar idea of science.
No, he doesn't.

43. Originally Posted by Neverfly
I'm getting a bit suspicious of Logic.
In his other thread, he's dropping some hints that he's got a pet hypothesis in cosmology to spell out what he thinks is Expansion.

He's also hinting at bordering on Tired Light... but going about it another way.
Originally Posted by logic
]you have a very peculiar idea of science.
No, he doesn't.
I do not have any pet hypothesis, Neverfly.
I am saying that anybody who draws from GR the conclusion that expansion destroys energy is an idiot.
Because , granted that GR is right or that universe is expanding, the scientific conlusion is that energy is simply diluted in wider surface ( 1/r^2)
So the logical conclusion as to cosmological shift is that total energy is the same but diluted in wider stretching spaceThe same as in Doppler effect: the difference is that there one body is moving away, and here the 2 bodies are drifting apart because of expansion
And whoever denies that every and each scientific statement needs proof, is presumptuous and dogmatic

44. Originally Posted by logic
I am saying that anybody who draws from GR the conclusion that expansion destroys energy is an idiot.
So you are calling some of the greatest theoretical physicists around "idiots"?

And whoever denies that every and each scientific statement needs proof, is presumptuous and dogmatic
Exactly the opposite of dogmatic. Science is built on uncertainty and provisional results: theories that have passed all tests so far.

Can you name one thing that has been "proved" (rather than disproved, which is slightly easier) in science?

45. Originally Posted by logic
I do not have any pet hypothesis, Neverfly.
My suspicions are not always valid. I hope that you do not crank out a pet hypothesis.
Originally Posted by logic
I am saying that anybody who draws from GR the conclusion that expansion destroys energy is an idiot.
Wording is important on such topics. At the very start of this thread- you should find some interesting posts and links on this. Do not assume others are idiots if you have not yet gained a fuller knowledge base on the subject.
Originally Posted by logic
So the logical conclusion as to cosmological shift is that total energy is the same but diluted in wider stretching spaceThe same as in Doppler effect: the difference is that there one body is moving away, and here the 2 bodies are drifting apart because of expansion
You did say that you do not have a pet hypothesis, right?

Originally Posted by logic
And whoever denies that every and each scientific statement needs proof, is presumptuous and dogmatic
Strange was correct to call you out on this line. Proof only exists in mathematics but nothing in science is proven. The use of the scientific method leads to building a model of reality that is tested and compared with observation in order to refine the accuracy of the model. The scientific method does not provide proof- it provides hard evidence and models of reality.

46. Originally Posted by Neverfly
Do not assume others are idiots if you have not yet gained a fuller knowledge base on the subject.
You did say that you do not have a pet hypothesis, right?
The scientific method does not provide proof- it provides hard evidence and models of reality.
THat is all completely wide of the mark.
You fail to realize that I have no theory, I am just drawing the logical conclusion from your theory. I am sure this particilar issue was not covered by GR or Einstein.
You say universe is expanding, right, use your brain now, if it is expanding its surface is stretching, bodies drift apart and so does frequency, what is your conceptual problem?
With gravitational shift it's another story, because energy really disappears. That is what I stated from the beginning: if you want to maintain that energy can be destroyed you are more convincing if you quote that instance.
If you cannot accept that, I cannot help it!

47. http://www.mso.anu.edu.au/~charley/p...DavisSciAm.pdf
Originally Posted by logic
THat is all completely wide of the mark.
Perfectly possible- but look at your posts so far. If you think I am in error... show me to be.

Originally Posted by logic
You fail to realize that I have no theory, I am just drawing the logical conclusion from your theory. I am sure this particilar issue was not covered by GR or Einstein.
The cosmological constant fiasco Einstein struggled with had nothing to do with this, right?
Originally Posted by logic
You say universe is expanding, right, use your brain now, if it is expanding its surface is stretching, bodies drift apart and so does frequency, what is your conceptual problem?
Originally Posted by logic
With gravitational shift it's another story, because energy really disappears. That is what I stated from the beginning: if you want to maintain that energy can be destroyed you are more convincing if you quote that instance.
If you cannot accept that, I cannot help it!
See where I posted that you can read the information right at the outset of the thread.

48. Originally Posted by logic
I am sure this particilar issue was not covered by GR or Einstein.
I'm not sure which "particular issue" you are referring yo here, but everything discussed so far is covered by GR.

With gravitational shift it's another story, because energy really disappears.
No it doesn't. In this case, energy is conserved.

49. Originally Posted by Strange
I'm not sure which "particular issue" you are referring yo here, but everything discussed so far is covered by GR.
There is only one issue , here.!!
What you say is simply false: Einstein had to disrupt original GR and drop his "biggest mistake" when Hubble discovered the expansion.
You are pretending competence you do not have.
Please quote the great scientists who say that in cosmological shift energy is destroyed , and quote how and the logical basis of that preposterousconclusion

51. Originally Posted by logic
What you say is simply false: Einstein had to disrupt original GR and drop his "biggest mistake" when Hubble discovered the expansion.
Exactly. He "fudged" GR to make it fit a static universe, because that was the accepted view at the time. Later it was found that this "mistake" could be removed so that GR more naturally describes the universe we live in.

Please quote the great scientists who say that in cosmological shift energy is destroyed , and quote how and the logical basis of that preposterousconclusion
See posts #3 and #33.

52. Originally Posted by Strange
See posts #3 and #33.
I am not a native speaker and inarticulate, if you are are articulate state your case, else, please, abstain

53. Originally Posted by logic
Originally Posted by Strange
See posts #3 and #33.
I am not a native speaker and inarticulate, if you are are articulate state your case, else, please, abstain
I am simply pointing you to the standard view of cosmologists. If you think these "idiots" are wrong, maybe you can explain why.

54. Originally Posted by Strange
I am simply pointing you to the standard view of cosmologists*. If you think these "idiots" are wrong, maybe you can explain why.
I have done that quite clearly, you are supposed to be a writer and haven't been able to put forward a single**argument, so far.

*is that blogger a top cosmologist?
**the one you gave in post #9 is risible (if you consider that a logical/scientifical explanation)

55. Originally Posted by logic
Originally Posted by Strange
I am simply pointing you to the standard view of cosmologists*. If you think these "idiots" are wrong, maybe you can explain why.
I have done that quite clearly
You started off asking the question, which was answered by reference to articles by experts in the field. You then say these experts are "idiots". Forgive me if I don't find that a very convincing argument.

you are supposed to be a writer and haven't been able to put forward a single**argument, so far.
I am not an expert in the field. I have no argument to put forward. I am simply telling you what the accepted science says. If you want to reject that for no good reason <shrug> whevs.

*is that blogger a top cosmologist?
**the one you gave in post #9 is risible (if you consider that a logical/scientifical explanation)[/I]
Which blogger? (there is no link in post 9).

56. Originally Posted by Strange
I am not an expert in the field. I have no argument to put forward. I am simply telling you what the accepted science says. .
I know that, my friend,
After 2 years I know you well, Strange, you acquired a smattering in GR sometime, and you can only paste and copy links and draw fancyful conclusions.

You can never make a sound , logical argument. And whoever dares to question your apodictical statements is a non-native, inarticulate, ignorant man who has a pet theory to grind.
(The blogger is in post #3 I suppose, in post #9 *you botched up an argument.)

But you can't even quote properly, because I begged you many times to quote the explanations of that statement , you were not even able to do so.
Does GR say that in cosmological shift energy is destroyed? NO! (show me where!), if not, ...who says so?, where exactly? does he justify if?, how? ( is it by chance what you hint at in post# 9?).
C'mon, Strange, I call your bluff once more.

P.S in an oscillation, energy is not an absolute quantity, but relative to time, if you produce a sound with k frequency for n seconds you produce nk total energy.
If you move toward the source at adequate speed you can experience nk energy in only one second. Only a fool would conclude that energy has been created (or viceversa destroyed). So if you change * a frame of reference you may (or may not) have a change of energy but that change,( if and only if the change of frame is relevant), is most probably apparent

57. Originally Posted by logic
But you can't even quote properly, because I begged you many times to quote the explanations of that statement , you were not even able to do so.
What is the point of me quoting from something I have provided a link to? I assume you can read it for yourself. I am just answering the original question asked, with references to sound scientific sources. You appear to disagree with the answer, but refuse to say why. I don't really care.

Originally Posted by logic
Does GR say that in cosmological shift energy is destroyed? NO! (show me where!), if not, ...who says so?, where exactly? does he justify if?, how? ( is it by chance what you hint at in post# 9?).
For example, Luboš Motl has said:
The energy conservation becomes vacuous or invalid in the general theory of relativity and especially in cosmology.
And:
Phil Gibbs is convinced that all relativists are wrong when they say that the energy conservation law is weakened, trivialized, corrected, or violated in general relativity in any way.

But they are right.
And:
Energy conservation explicitly fails in cosmology
The Reference Frame: Why and how energy is not conserved in cosmology

And Sean Carroll:
Energy isn’t conserved; it changes because spacetime does.
Energy Is Not Conserved | Sean Carroll

Can you provide any references to cosmologists who say that energy is conserved (or even well defined) on cosmological scales? (Hint: read the quotes above!)

58. You are not quoting Einstein, but two modest physicists, in the first place.

But what is relevant here is that they say that the law of conservation is generally not valid in GR., Fair enough: in theory everything is possible I do not care, but that should be substantiated with at least a couple of real , verifiable examples.

That, anyway, does not mean that the law is never valid, Strange. Here is where you go astray. You are living in the same Universe now, I suppose, and you can experience many instances in which energy is conserved.
Your logical disconnect/ fallacy is here: you should show that redshift is one of those instances of real loss of total energy.

In order to do so you cannot base your judgement on any local measurement, you should find out the amount of total energy nk emitted, and then compare it with the total amount of energy nk' now existing. Which neither you not you couple od friends , nor anyone can do. Can you understand that?

So your statement is not a statement by Einstein, not a statement by any cosmologist, not a statement by Carrol/Motl, but a statement (ungrounded conclusion) by Strange and Neverfly.

If you care , you may try to justify your other statement that in gravitational shift energy is not destroyed, what gets that energy?

59. Originally Posted by logic
You are not quoting Einstein, but two modest physicists, in the first place.
So what? Why does it matter what Einstein might have said about the matter? This isn't a religion where we have to refer back to "the prophet".

Lubos Motl could hardly be described as modest. (But he has little to be modest about). The others are leading cosmologists.

But what is relevant here is that they say that the law of conservation is generally not valid in GR.,
Exactly.

but that should be substantiated with at least a couple of real , verifiable examples.
Energy lost by photons (and neutrinos) due to cosmological red shift?

That, anyway, does not mean that the law is never valid, Strange.
Of course not. No one would say such a thing. It is obviously valid, locally. It is a fundamental conservation law (see Noether's theorem for details).

60. Originally Posted by Strange
Energy lost by photons (and neutrinos) due to cosmological red shift?
.
If the issue at hand is a real verifiable example, tell me by whom, when, how and where it has been verified, it is so simple!

61. Originally Posted by logic
If the issue at hand is a real verifiable example, tell me by whom, when, how and where it has been verified, it is so simple!
What do you mean by "verifiable example"? Are you suggesting that we don't see photons red-shifted by the expansion of the universe? Or the CMB at a much lower temperature than when it was emitted?

(I'll withdraw the neutrinos as I'm not sure we have measured neutrinos that we know to be the equivalent of the CMB).

62. On the one hand you say energy is created (i.e. not conserved):
Originally Posted by logic
But we accept that we must accept that encergy is constantly being created in large amounts inside the atoms
But you also say that anyone who denies conservation of energy is an idiot. So, logically, does this make you an idiot?

63. Originally Posted by Strange

But you also say that anyone who denies conservation of energy is an idiot. So, logically, does this make you an idiot?
I was listing the absurd logical consequences of your statement.

64. Originally Posted by Strange
What do you mean by "verifiable example"? Are you suggesting that we don't see photons red-shifted by the expansion of the universe?
I think that's enough, Strange!

65. Originally Posted by logic
I think that's enough, Strange!
Good. I'm glad you are satisfied with the evidence.

66. Originally Posted by logic
I was listing the absurd logical consequences of your statement.
You are very keen to demand I explain standard science (which you can easily look up) and yet you are unwilling to explain why or how you have invented the idea that nuclei "continuously create energy".

67. Logic doesn't seem to know much about any details regarding GR or cosmology. Anyone who demands 'proof' doesn't appear to understand how the scientific method works. He applies 'reason' and 'logic', based upon weak and faulty knowledge, and makes unsupported assertions.

68. Originally Posted by logic
I have read that conservation of energy is not true in absolute, if that is true, could anyone tell me a couple of instances when energy is distroyed?
Those FAQ pages are nice. I'd like to add to it from something I read recently

A friend of mine printed out a great GR book for me that's online at http://bookos.org/dl/1447929/d5d28c and by Hans Stephani.

Regarding gravitational energy on page 237 he writes
Over large spatial regions when the gravitational field is properly included there is no energy balance equation. It is incorrect to regard this as a violation of energy conservation; there exists in general no local covariant quantity 'energy' to which the property of conservation or non-conservation can be ascribed. None of the foundations of physics are thereby destroyed; energy is only a (very important) auxiliary quantity for describing interactions, but the interaction of all parts of the Universe is quite essential for the theory of gravity.

69. As I said- suspicious.

Cranks often start out by asking a simple question, then declaring they have no pet hypothesis even after they present it, then try to prove Relativity wrong.

This guy has learned to cover his ass a lot, is all.

70. And then wanders off when he is shown to be wrong ...

71. Originally Posted by PhyMan

Over large spatial regions when the gravitational field is properly included there is no energy balance equation. It is incorrect to regard this as a violation of energy conservation; there exists in general no local covariant quantity 'energy' to which the property of conservation or non-conservation can be ascribed. None of the foundations of physics are thereby destroyed; energy is only a (very important) auxiliary quantity for describing interactions, but the interaction of all parts of the Universe is quite essential for the theory of gravity.
You seem most competent member on the issue and sound like a professional physicists. Could you please explain the reason why we cannot assume that in cosmological shift energy is conserved? ( it that is true)

72. Yet there is no conclusion, we have to look it into deep
Some people are always ready to declare quick conclusion and displace the very tested and fundamental laws

73. Originally Posted by logic
Could you please explain the reason why we cannot assume that in cosmological shift energy is conserved? ( it that is true)
Why do you keep asking the same damn question that has been answered multiple times? Are you waiting for someone to spew the answer you want?

In case you missed it, here it is again: Energy is a frame-dependent quantity. There is no universal frame that spans the universe. Ergo, there is no proper way to perform the accounting necessary to compute conservation for the entire universe, and thus one cannot say that redshift does or does not imply a failure to conserve energy.

That's it. Period. Don't like the answer? Tough.

74. Logic strongly reminds me of theorist.

75. Originally Posted by AlexG
Logic strongly reminds me of theorist.
I have the same feeling of deja vu/deja lu. I wonder if socks and puppets are involved...

76. No, despite his appalling spelling and grammar, theorist was obviously a native English speaker (and English, I think). But I'm fairly sure logic is not a native speaker. He reminds more of fiveworlds who also strings together random poorly-understood facts in order to support bizarre opinions.

77. Originally Posted by AlexG
Logic strongly reminds me of theorist.
If you don't mind me asking, who's that and why does he remind you of them?

78. Originally Posted by PhyMan
Originally Posted by AlexG
Logic strongly reminds me of theorist.
If you don't mind me asking, who's that and why does he remind you of them?
Theorist had/has a style in which he would begin with questions, and then shift to pretending not to understand the answers, to rejecting those answers outright and then providing his own nonsensical answers. He was absolutely impervious to learning, but would arrogantly declare his ill-formed, illogical beliefs as true.

Logic's style is a little similar, although I see Strange's point. Perhaps logic is a long-lost cousing of theorist...

79. Originally Posted by tk421
Originally Posted by PhyMan
Originally Posted by AlexG
Logic strongly reminds me of theorist.
If you don't mind me asking, who's that and why does he remind you of them?
Theorist had/has a style in which he would begin with questions, and then shift to pretending not to understand the answers, to rejecting those answers outright and then providing his own nonsensical answers. He was absolutely impervious to learning, but would arrogantly declare his ill-formed, illogical beliefs as true.

Logic's style is a little similar, although I see Strange's point. Perhaps logic is a long-lost cousing of theorist...
This forum is full of such characters, what does it take to get rid of them?

80. Originally Posted by xyzt
This forum is full of such characters, what does it take to get rid of them?
I don't think it's possible. I used up a whole case of Wacknut-B-Gone(tm), to no effect.

81. Have you seen a place where you learn with no joke flashing in αη∂ out sometimes?

82. Just yesterday I made a great discovery. If the fact that the speed of light is reducing over time is applied to E=mc2, then E=mc12-mc22 must be true. This implies that, as time goes by, all mass loses energy (which explains why atomic clocks cannot be used to verify the change in the speed of light). Now, this energy goes nowhere; it ceases to exist! So, to prove this theory, the speed of light must be measured using orbital clocks twice at an interval, and the resulting measurements can be inputted to my formula along with the mass of any object to find exactly what amount of energy is lost within the time-frame between measurements of the speed of light. This is the theory of constant universal energy loss.

83. Originally Posted by Garkonn
If the fact that the speed of light is reducing over time
Where did you get this "fact" from?

84. Plucked from an orifice? Or from that most unimpeachable of sources, youtube?

85. Schools out for the summer? Heat makes the nuts sprout?

86. Where did that guy come from with speed of light reducing with time?

87. Originally Posted by Strange
Originally Posted by logic
Originally Posted by Strange
The metric expansion of space made the energy disappear.
What proof is there of that?
"Proof"? What an odd question. This is science.

Anyway, this is what is described by relativity, which is an extremely well tested theory. About as close to "proof" as you get in science. See posts #3 and #33.
I'm not sure that characterization is exactly accurate if you mean to apply it to the metric expansion of space. There many other hypothesis in physics which stand on stronger evidence than metric expansion does.

All the evidence we have for metric expansion is the observation that light is being red shifted according to distance. There have been increasingly accurate measurements taken, which prove, beyond any reasonable doubt that..... light is being red shifted according to distance. Massive telescopes in space have looked very far into space and confirmed that..... light is being red shifted according to distance. Not one shred of evidence exists that metric expansion is the cause. There are plenty of arguments from incredulity (- eg. "If it's not metric expansion, then what is causing it?" "You can't tell me? Ok, then it must be metric expansion.")

Metric expansion stands on strong consensus. And dogmatically reinforced by the insistence that there needs to be one theory to explain 3 separate phenomena - which is just dogma. There are many other situations in science where separate phenomena were explained by separate theories, but it appears that in this one case requires the three to converge into one. Why? I don't know. I guess it's because somebody important said so.

88. Originally Posted by kojax
All the evidence we have for metric expansion is the observation that light is being red shifted according to distance.
I've noticed from your posts that you have a relatively poor grasp of physics, but I see now that the problem goes beyond a lack of education. It appears that you have a dogmatic resistance to what is known. That's serious, especially since you frequently provide answers with an assurance that is belied by their unreliability. When you assert things such as

Not one shred of evidence exists that metric expansion is the cause. There are plenty of arguments from incredulity (- eg. "If it's not metric expansion, then what is causing it?" "You can't tell me? Ok, then it must be metric expansion.")
one must assume that you either haven't heard about the CMB, or that you ignore it because what it implies is at odds with some unstated dogmatic belief you hold.

The evidence points to a past that was hotter than it is now. Redshift, the CMB (both its exquisite conformance to a blackbody spectrum, as well as its tiny deviations from it), light-element nucleosynthesis -- to name a few -- all point toward metric expansion. Sure it's possible that these are all the result of separate processes that miraculously point toward a single conclusion, but it's Occam's Razor that leads one to treat them all as a consequence of a single mechanism, not dogma. If data were to arise that occasions a revisiting of the Razor, we'd revisit it. That's not the attitude of a dogmatist. It's the attitude of a scientist. You, on the other hand, prefer to pretend that metric expansion is invoked "just because," presumably for reasons that are quite personal to you. It's fine for you to believe as you wish, but it is a completely false characterization to declare that there is no evidence for metric expansion.

Metric expansion stands on strong consensus.
And that consensus is the result of examining the evidence, kojax.

And dogmatically reinforced by the insistence that there needs to be one theory to explain 3 separate phenomena - which is just dogma. There are many other situations in science where separate phenomena were explained by separate theories, but it appears that in this one case requires the three to converge into one. Why? I don't know. I guess it's because somebody important said so.
Bullshit.

89. Originally Posted by tk421
Originally Posted by xyzt
This forum is full of such characters, what does it take to get rid of them?
I don't think it's possible. I used up a whole case of Wacknut-B-Gone(tm), to no effect.
This is getting intolerable, the forum is drowning in crackpots.

90. Αη∂ what do you suppose xyzt?

91. Originally Posted by xyzt
Originally Posted by tk421
Originally Posted by xyzt
This forum is full of such characters, what does it take to get rid of them?
I don't think it's possible. I used up a whole case of Wacknut-B-Gone(tm), to no effect.
This is getting intolerable, the forum is drowning in crackpots.
Yes, this has been my feeling for a while now. Every so often when I get particularly exasperated by it I post here about it, but whatever we try to do, they just keep coming.

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