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?
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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.
Is Energy Conserved in General Relativity?In general — it depends on what you mean by "energy", and what you mean by "conserved".
The Reference Frame: Why and how energy is not conserved in cosmologyThe precise answers will depend on what you mean by energy and what situation you consider.
Or, to put it another way: it's complicated.
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 itMental note to not keep a reponse unsubmitted without checking for updates to the thread made)
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.
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
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?
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...
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 ?
Pretty much anyone who understands the mathematics of GR, as far as I can tell.
For example, Luboš Motl (see link above) has said:
And: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 Sean Carroll:Energy conservation explicitly fails in cosmology
Energy Is Not Conserved | Sean CarrollEnergy isn’t conserved; it changes because spacetime does.
And John Baez (see link in previous post).
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.
No one is doing that.
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.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.
That is yet another souyrce of red-shift. But it is not what causes cosmological red-shift.
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?But we accept that we must accept that encergy is constantly being created in large amounts inside the atoms
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.
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.
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.
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?
[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
Ah, OK, scale factors.....Thanks for the pointer...I'll need to read this up......
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?
Er, what? And no.you are implying theat gravity creates energy that annihilates energy.
No.And then you must accept that electric field creates energy too.
Well you got something right, at least.Moreover getting hot has nothing to do with creation of energy, you get hot on a fire, even if you are only transforming energy
Do you want to explain why you think nuclei continually create energy? What is the evidence for that? And where that energy goes?
So far your communication style (random incorrect statements with no apparent connection between them) appears to contradict your username.
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?
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.)
I'm afraid most of your statements make little sense to me. And you are strangely reluctant to explain...you must accept the whole chain of [I]random statements.
Can you explain why you think nuclei continually create energy? What is the evidence for that? And where that energy goes?
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
No, it isn't.
I don't. Why do you keep saying that?If you think in gravitational shift energy is lost
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).even the the asteroid: where has that energy come from?
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?and the nuclei
What does that mean? I assume English is not your native language. I am struggling to make sense of most of your statements.If GR is agnostic
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.
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
OK?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".
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.
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.
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
So you are calling some of the greatest theoretical physicists around "idiots"?
Exactly the opposite of dogmatic. Science is built on uncertainty and provisional results: theories that have passed all tests so far.And whoever denies that every and each scientific statement needs proof, is presumptuous and dogmatic
Can you name one thing that has been "proved" (rather than disproved, which is slightly easier) in science?
My suspicions are not always valid. I hope that you do not crank out a pet hypothesis.
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.
You did say that you do not have a pet hypothesis, right?
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.
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!
http://www.mso.anu.edu.au/~charley/p...DavisSciAm.pdf
Perfectly possible- but look at your posts so far. If you think I am in error... show me to be.
The cosmological constant fiasco Einstein struggled with had nothing to do with this, right?
See link I pasted above.
See where I posted that you can read the information right at the outset of the thread.
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
Last edited by logic; June 2nd, 2013 at 05:47 AM.
Explain why you started this thread asking the question, please.
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.
See posts #3 and #33.Please quote the great scientists who say that in cosmological shift energy is destroyed , and quote how and the logical basis of that preposterousconclusion
Last edited by logic; June 2nd, 2013 at 07:05 AM.
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.
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.you are supposed to be a writer and haven't been able to put forward a single**argument, so far.
Which blogger? (there is no link in post 9).*is that blogger a top cosmologist?
**the one you gave in post #9 is risible (if you consider that a logical/scientifical explanation)[/I]
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
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.
For example, Luboš Motl has said:
And: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.
The Reference Frame: Why and how energy is not conserved in cosmologyEnergy conservation explicitly fails in cosmology
And Sean Carroll:
Energy Is Not Conserved | Sean CarrollEnergy isn’t conserved; it changes because spacetime does.
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!)
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?
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.
Exactly.But what is relevant here is that they say that the law of conservation is generally not valid in GR.,
Energy lost by photons (and neutrinos) due to cosmological red shift?but that should be substantiated with at least a couple of real , verifiable examples.
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).That, anyway, does not mean that the law is never valid, 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? 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).
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.
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.
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.
And then wanders off when he is shown to be wrong ...
Last edited by logic; June 4th, 2013 at 03:27 AM.
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
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?
Strange already linked you to numerous sources with the answer. I gave you a pointer to Noether's theorem(s). You have the answer.
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.
Logic strongly reminds me of theorist.
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.
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...
Have you seen a place where you learn with no joke flashing in αη∂ out sometimes?
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.![]()
Plucked from an orifice? Or from that most unimpeachable of sources, youtube?
Schools out for the summer? Heat makes the nuts sprout?
Where did that guy come from with speed of light reducing with time?
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.
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
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.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.")
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.
And that consensus is the result of examining the evidence, kojax.Metric expansion stands on strong consensus.
Bullshit.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.
Αη∂ what do you suppose xyzt?
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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