In Brief
- As the universe expands and distant galaxies recede from us, their light gets redshifted, thus becoming less energetic.
- This seeming violation of the principle of conservation of energy is actually not in contradiction with accepted physical laws.
- According to the author, the proper interpretation shows that the energy of individual photons is conserved. And phenomena taking place inside the galaxy generally conserve energy.
Energy can neither be created nor destroyed. This principle, called conservation of energy, is one of our most cherished laws of physics. It governs every part of our lives: the heat it takes to warm up a cup of coffee; the chemical reactions that produce oxygen in the leaves of trees; the orbit of Earth around the sun; the food we need to keep our hearts beating. We cannot live without eating, cars do not run without fuel, and perpetual-motion machines are just a mirage. So when an experiment seems to violate the law of energy conservation, we are rightfully suspicious. What happens when our observations seem to contradict one of science’s most deeply held notions: that energy is always conserved?
Skip for a moment outside our Earthly sphere and consider the wider universe. Almost all of our information about outer space comes in the form of light, and one of light’s key features is that it gets redshifted—its electromagnetic waves get stretched—as it travels from distant galaxies through our ever expanding universe, in accordance with Albert Einstein’s general theory of relativity. But the longer the wavelength, the lower the energy. Thus, inquisitive minds ask: When light is redshifted by the expansion of the universe, where does its energy go? Is it lost, in violation of the conservation principle?
This article was originally published with the title Is the Universe Leaking Energy?.
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Add CommentThe answers to the puzzles posed in Tamara Davis' article, 'Is the Universe Leaking Energy' can be found in my book, 'Einstein, the Aether & Variable Rest Mass,' available through Amazon, Barnes & Noble, Lulu.com, or my website, 'stenosphere.com'. My analysis is based upon the conservation of momentum, which follows from the presumed large scale homogeneity of the universe. It is concluded that the function presently thought to describe the expansion of space itself, actually describes the evolution of rest masses, which increase with time. Since emission frequencies are directly proportional to the electron rest mass, the red shift is seen to be a simple consequence of the fact that rest masses were in past epochs much reduced as compared with present values. Since this effect accounts for the red shift, it is clear that the universe is not expanding.
Reply | Report Abuse | Link to thisThe simple answer is that the universe is expanding, dispersing its energy throughout space and time. Universal mass-energy density is decreasing, but it is being conserved, thank you. Don't worry about the photons: they'll be fine.
Reply | Report Abuse | Link to thisThis disregarding the silly accelerating universe misunderstanding...
This is only one of the many proofs that light is an E.M.wave. That i was a a wave was known before Maxwell found its E.M.nature
Reply | Report Abuse | Link to thisAn expanding Universe is not the only way a photon can lose energy (assuming the Universe is, indeed, expanding). If a photon passes a mass, it will blue shift upon approaching the mass. As it leaves the mass, it will red shift. The red shift is greater than the blue shift because the photons trajectory has bent in toward the mass so dives up out of a deeper well than it dove into. Therefore when it reaches infinity it will have a net red shift. This interaction with masses passed in space could easily account for all or most of the red shift as a photon moves through space. You may see a discussion of this in http://charles_w.tripod.com/red.html .
Reply | Report Abuse | Link to thisI reply to the Leaking Light article:
Reply | Report Abuse | Link to thisI hope this article is complete(as I see another author has had to explain his position (as SA seems to be more like the Readers Digest in conserving paper and advertising space) and caused unnecessary use of paper it tried to save in the preceding issue).
Thank you to Dr. Davis for assisting my further musing on the Big-Bang Theory. I have long hated the words and theory as it is a poor and simplified Creationist Construct. I also have some heart-burn with your descriptions and use of some terms. I think Balance is a better descriptor than Symmetry in this case and is the key to an obvious clue I had previously discounted. Symmetry is exactly why Big-Bang is mostly incorrect. The fact that galaxies are moving away from a point in space at all different rates and directions says that there could not have been a singularity from which they emerged. Even our simple counting-mathematics would require a symmetric, balanced, and regular geometric output of expanding matter, indeed spherical. And I know of no such regularity Anywhere. In order for the observed behavior to be correctly described, an external influence on the bang must be in the equation, and I have heard no one admit that to the formula. It is My contention that a Bang is more likely describing (partially correct part)the behavior of a Black Hole and My assumption of the fabric of the universe is that there are several percent of all the objects in the sky in motion either expanding or collapsing. Time is also a problem in that it is not a useful way to measure the activity of the universe. Even the simple motion of a pendulum is easier to examine by its amplitude and energy in place of time. Counting math makes it so difficult to understand gravitation, friction, and chaotic motions. It is better to use energy level or motion(frequency) as a coordinate system rather than time. Time is regular and counting is too difficult to correctly describe a chaotic behavior. I think the measurement must follow the natural frequency of the material and if that is too complicated then you must reference your relationships based on a single common element, say Helium. If all relationships can de described through the exchanges of energy and light referenced to Helium you can then describe the actions of the concentrations of energy and corresponding absences(kinds of black holes and various kinds of suns). The models of plane and plain geometry fail to describe the universe: all the illustrations and images I have seen of planetary and galactic systems show a kind of oblate sphere, more like flying-saucer shape, and irregular. There is no way I can believe a spherical creation/explosion would Not lead to a spherical planetary system consequence. I have not seen or heard anyone describe a planetary system as a sphere and if the singularity of a Big-Bang were then saucer-shaped, why is that so? I have not heard that description or assumption so am not certain it was indeed spherical. My knowledge of magnetism suggests that matter behave in reaction to polarities of celestial bodies and systems and that would explain some of the behavior of materials and distortions of time: When youre looking along a pole versus a plane for time events, it will be distorted by the energy levels and you cannot easily relate one to the other. My contention is that because of the chaotic arrangement of magnetic fields and materials in the galaxies, time is only a confusing way to try to sort things out!
In Aether Wave Theory (dense aether theory) Universe appears like giant nested density fluctuations of hypothetical random gas, i.e. it's completelly random, ethernal, its energy doesn't dissapear or form. Red shift of visible light is ballanced by blue shift for radiowaves.
Reply | Report Abuse | Link to thisisoptera - Possibly, but the amount of lights' redshift is a function of the distance/time traversed, the net temporally varying spacetime expansion and the resulting density of the universe. As the universe expands, light is decreasingly likely to pass near enough objects that are massive enough to alter its spectrum.
Reply | Report Abuse | Link to thisIt seems to me that all extragalactic light would have been redshifted by similar 'flybys' of galactic objects, as well as all intragalactic light, as a function of its distance traversed. Of course, light from objects within our own Milky Way galaxy apparently do not exhibit significant redshift.
It seems most likely to me that the density of masses within the Milky Way galaxy is much greater than the density of galaxies in intergalactic spacetime. If most or even any significant amount of light's redshift were produced by the very near traversals of mass curved spacetime, required to redshift light, I would expect much more redshift of intragalacitc light than intergalactic light.
I'm not a physicist but isn't energy once dissipated lost forever? Isn't this the basis of entropy/enthalpy? Won't there be an final equilibrium of mass - energy at some point in the future?
Reply | Report Abuse | Link to thisdbtinc - Me neither, but if I recall correctly mass-energy can be converted but not created or destroyed. Dissipated energy may be more difficult to extract, but it still exists. If I immerse a hot iron into a bucket of water, I can still warm my foot with the dispersed energy.
Reply | Report Abuse | Link to thisI'm planning on writing a book called "Scientific American forums: the YouTube comments of smart people. A story of how the anonymity of the internet allows anyone to pretend to be an expert on anything, even subjects the smartest people in the world are struggling over daily, without any proof of credentials whatsoever". Think anyone will read it?
Reply | Report Abuse | Link to thisHas anyone wondered if HAARP might be an influencing factor??
Reply | Report Abuse | Link to thisThis is only a problem if the speed of light is constant.
Reply | Report Abuse | Link to thisIf the speed of light depends on the Gravitational Potential level, then as the Universe expands, the light is stretched & the Gravitational Potential level decreases, the speed of the light will increase (but so does the rate of time; so to a local observer it appears to be constant).
Thus the light will be at a lower frequency, but a higher speed - but the same total energy content.
See my papers on Energy Field Theory at www.wbabin.net for similar explanations of the kinematic effects of Relativity...
This article shows its author does not know the laws of physics.Light has the same velocity and energy before and after red-shifting. Why should it be different?Why considering the universe as the same laws hold in a laboratory . If light loses energy by red-shifting the military could use red-shifters as weapons
Reply | Report Abuse | Link to thisBut it would make more sense to say the universe loses energy by radiation The mean temperature of the universe is 2�K so it always radiates energy;Where does this energy go?
If the universe is expanding, which I would imagine requires some input of energy, then it makes sense that the energy "lost" in the redshift might be energy going into the continued expansion of the universe. If, however, the universe singularity is a black hole, and not the big bang, the redshift energy could be energy used to maintain some sort of equilibrium between the galaxies and the universe center.
Reply | Report Abuse | Link to thismorp - I don't know physics, but I thought that gamma rays are considered have more energy than radio waves, I think by virtue of their wave density or something. Based on this 'ranking', I think that a wave of higher energy will penetrate farther through matter - perhaps its 'effective mass' is greater...
Reply | Report Abuse | Link to thisIntresting idea SkepticizeMeCapn. I am my self is an expert in human cognition and sociology and I think it is a Great idea that worth more rigorous study.
Reply | Report Abuse | Link to thismorp - Also, I think it makes more sense to say that the univere's energy is being dispersed throughout the increasing spacetime. Energy density is diminished; the mean temperature decreases, but all its initial energy is still contained within the generally expanding universe.
Reply | Report Abuse | Link to thisThis does general dispersal of energy does not apply to the same extent for intragalactic spacetime, which is not generally expanding. EM radiation still disperses at distance in any case.
It is confusing to discuss the total energy of photons within an 'imaginary expanding membrane' without relating the measurement to a single reference frame. But no single comoving observer's frame is directly relevant to the motion of ALL photons in the membrane, the vast majority of which will never contact it. Moreover, all potential observer frames are in motion relative to each other. However, consider an aggregation of calculations in which each photon's energy is measured over time with respect to its own emitting galaxy's reference frame. Each photon's momentum will decay (redshift) over time relative to its emitter, but if its energy is calculated to be its [coordinate momentum x coordinate velocity] relative to its emitter, then this decrease in momentum is exactly offset by the increase in velocity as the photon traverses (at a local velocity of c) regions of ever higher Hubble recession velocity [H x D] relative to its emitter. From this perspective all photon energy is strictly conserved.
Reply | Report Abuse | Link to thisjonmtkisco - Yeah, this relativistic stuff gets too complex for me, but aren't all observed, known photons in the universe detected in some local observer's frame of reference? All the light that has not been detected by anyone here in Earth's immediate neighborhood are completely unknown. Is the position of any distant light's emitter determinable in any meaningful terms, considering that there is so little information about the conditions of the universe at the moment of emission that can be determined?
Reply | Report Abuse | Link to thisOf course, we could just make a lot of assumptions, based on where we think the emitter is in our view of the sky and what it was like out there...
But I don't really know anything about it.
Nonsense, the red shifted light we observe is balanced by the blue shift observed by an observer, if any, on the far side.
Reply | Report Abuse | Link to thisburlcl...just because we are moving away from a galaxy to the north does not mean we are moving toward a galaxy to the south...space is expanding....both can and will be redshifted if far enough away....remember, the universe is not a sphere...
Reply | Report Abuse | Link to thisWe can rely on Einstein's physics and fractal size invariancy with black holes. Since simultaneous occuring events as described in the article vary depending on the observers, then the age of the universe will vary depending on how fast they are traveling through space since the big-bang. What is pulling the wool over our eyes? A false Belief that size matters for black holes, and that mini-atomic black holes have a different principle and are different then supernova and supermassive black holes. aligned 3-d Spins of black holes can form larger hierarchs, and are self-similar by all sizes, meaning they should support stars and planets in their own singularities of existance. visible matter observations reveal similarities wi hydrogen ions swarming in the same direction to form a star then a galaxy and continue into superclusters and the dark flow mass at 150 billion LY.
Reply | Report Abuse | Link to thisjtdwyer - There is no one way to know the exact distance to a very distant galaxy from which light received now on earth was emitted. But the distance parameters that cosmologists use in their calculations are much more than "assumptions". They are based on a highly detailed mathematical and cosmological model called the "Standard Model" or "Lambda-Dark Cold Matter model. (LCDM)" The accuracy of the Standard Model has been tested in many sophisticated ways. It has proved to be very consistent with observations of a number of cosmic phenomena, such as the Cosmic Microwave Background, the luminosity of distant stars which are regular enough to be used as "standard candles" (e.g., Cepheid variable stars, type 1a supernovae) and what particle physics tells us about the relative abundance of certain elements in the early universe (Hydrogen, Helium, etc). This is added to the assumption that the distribution of galaxies in the universe, at very large scales, is homogeneous and isotropic (the "Copernican Principle"). The "Friedmann-LeMaitre-Robinson-Walker (FLRW)" metric provides the mathematical basis for the Standard Model, and it is an exact solution to Einstein's equations for General Relativity. All of this fits in well with the measured redshifts of galaxies at various distances. The standard model is not entirely complete, and there are many profound open questions about it (the nature of dark energy, dark matter, inflation, etc.) but it would take something quite unexpected to fundamentally displace it in current cosmology. So yes, we can make solid assumptions about the distance to a galaxy at the time of emission, and derive the formula for the redshift from that. Much can be learned by reading some of the many articles on Wikipedia about cosmological subject matter.
Reply | Report Abuse | Link to thisI should mention that my original post suggests a non-standard way of calculating photon energy. Normally, photon energy is calculated as, simplistically stated, [momentum x c], with c being the locally measured speed of light. This provides a "local" energy figure, and is what leads to the dilemma that the energy of photons when measured locally seems to decline over time. My suggestion is that if the photon's energy is calculated using its coordinate velocity relative to its distant emitter, instead of using its local velocity c, the apparent paradox of decaying photon energy does not arise.
Reply | Report Abuse | Link to thisCoordinate velocities can be validly measured across large distances in curved spacetime. For example, there is no problem extending Hubble recession velocities to large distances, even when the Hubble velocity exceeds the speed of light (beyond the Hubble Sphere). And note that when Hubble velocity segments are summed in curved spacetime, no special relativistic adjustment factor is applied.
jonmtkisco - I apologize for my earlier comment: it was mostly tired babble. Your assessment is a very good perspective - thanks.
Reply | Report Abuse | Link to thisHowever, the standard cosmological models that determines distances primarily from redshift were initially calibrated more than 50 years ago, I think, for the relatively nearby galaxies then visible using available telemetry equipment.
If, as some data indicates, the more ancient light emissions from much more distant galaxies indicates that conditions were much different than they are now, it would not be surprising if those standard models did not correctly predict the distance that more ancient light has traversed.
If the unproven dark matter and dark energy hypotheses do not describe actual physical entities, a significant adjustment would be required to produce a representative model of the universe.
While I have no qualifying credentials in in this area, I have had more than 30 years experience with the world's largest information systems, and have identified and corrected many very difficult problems in complex systems. From my perspective some of the most crucial elements in the current standard model are product of misinterpretations. I've posted an essay addressing the 'discovery' dark matter at:
http://www.sciencewithoutfiction.com/uploads/Mass_Distribution-_Galaxy_Rotation_Problem.pdf
Very difficult problems that seem insolvable to the most knowledgeable subject area experts are often the result of commonly held misconceptions. There is no possibility that I can learn more about astrophysics than even informed amateurs, but I hope to help by applying my experience in perceptive problem identification.
jonmtkisco - Thanks for explaining. To the extent that I can comprehend, that the differential emission velocity accounts for the apparent discrepancy, I expect that you are correct and that this resolves the issue within the context of the article.
Reply | Report Abuse | Link to thisI realize that you are using the terminology of established methods when you refer to 'the Hubble recession velocity' but doesn't this observer-centric perspective promote the conception that all distant galaxies are actually receding away from Earth, when the Milky Way is also receding away from all other galaxies?
If it's considered that light from distant galaxies was emitted long ago, isn't it arguably more correct to consider that the Milky Way has been receding away from the approaching ancient light emission? While this may seem pointless, I think that referring to the recessional velocity of distant galaxies leads to misconceptions about what is more correctly an extension of the wavelength of ancient light as it traverses expanding spacetime.
I think it is just as valid to consider that the Milky Way is receding away from the ancient light emissions of all distant galaxies, and that if more distant galaxies are further away than standard cosmological models predict it is because their more ancient light emissions were subjected to greater spacetime expansion than those standard models presume, based on more recent light emissions.
But I'm rambling, and deviating from the context of established methods...
I thing this:
Reply | Report Abuse | Link to this(Sorry for my bad english)
The Universe is a Wave of THREE DIMENSIONS in a FOUR DIMENSIONS BRANE.
Imagine a lake. A Stone make ��Chop!! in the center of the lake. This is a Singularity: This is the Big Bang.
In the surface of the lake born a Wave. It is a Space of ONE dimension EXPANDING in a surface of TWO dimensions.
The wave is expanding at constant velocity. If several flies make surf in the wave, each one thing that the others are far, far away, they more far run more speed. As the galaxies run away, more speed the more far.
Our Universe is a Wave of THREE dimensions expanding across a brane of FOUR dimensions.
We are 3D persons, living and thinking in 3D and we not undertand the four dimensions, but the origin of universe, the place where ocurrs the Big-Bang (the stone that fall on the center of the lake) is not in our universe, but in the center of the wave of our universe, in a direction that we can't see or sign with our fingers.
Conclusions: Expansion of Universe is constant.
Energy amount is constant, but our Universe is more and more big. This make that the amount of energy by year/light cubic will be less and less.
The light that come from far galaxies travel to we while the wave is increasing and this make that the trayectory of the lights is a exponential curve, where the distances from far galaxies is bigger that all we thing.
Item plus: ��We can see galaxies so far that run away more speed than the light!!
jtdwyer - No, most of the observations that are being used to establish distances and support the Standard Model were made in the past few years. Particularly the WMAP satellite's mapping of the Cosmic Microwave Background, and the analyses of type 1a supernovae. The recent years have been a golden age of cosmic observation. It was only around 1998 that enough observations were obtained to tentatively conclude that the expansion is accelerating rather than decelerating as previously believed. We have far better observational data now than we did even 10 or 20 years ago.
Reply | Report Abuse | Link to thisFor the purpose of mathematical calculations, it doesn't matter whether the distant emitter galaxy is considered to be receding away from us, or we are receding away from it. It's the relative velocity as between us that's important. And besides, in the FRW metric, any purely comoving observer is entitled to treat themselves as being stationary, with everything moving away from them the Hubble flow. The issues you raise here are far too basic to trip up cosmologists. I urge you to study some cosmology before espousing new theories on this subject. You will quickly come to appreciate how solid data and expert analysis has advanced our understanding and strongly ruled out most alternative explanations.
Reply | Report Abuse | Link to thisjonmtkisco - I have examined the paper identifying the accelerating universe. As I understand, the distance to the galaxies in which type Ia SN were observed was determined was based on standard cosmological models which were based on the redshift of galactic light. Of course the (presumedly more precise) distance to the SNe was based on luminosity.
Reply | Report Abuse | Link to thisSo, for the more distant groups of SNe observed, the SNe distance estimates exceeded those of their host galaxies. For the nearer group SNe both distance estimation methods yielded comparable results.
From this it was concluded that the expansion of the universe is accelerating.
I suggest that considering that the most distant objects are receding away from us faster than nearer galaxies is a misconception.
I suggest that the data simply indicates that the more ancient light emissions were subjected greater rates of spacetime expansion than more recent ones: that the data indicates that the expansion of the universe has decelerated, in accordance with the most fundamental laws of physics.
Now that the accelerating universe is so firmly established, considering that the observational data supports the most fundamental laws of physics and expert astrophysicists very simply misinterpreted their observations may be heretical, but I think the more extraordinary claim demands the extraordinary evidence. It's too soon to casually dismiss the possibility that astrophysical procedures that have been calibrated for recent conditions may not apply correctly for the conditions of the early universe. No matter how expert the experts are.
jtdwyer - I'm not going to respond further on this point, but I'll mention that the Standard Model already incorporates an enormously faster expansion rate in the very early universe. Gravity caused the expansion to decelerate for the first 7GY or so until dark energy began to dominate over gravity, and the expansion began accelerating. The deceleration since the Big Bang (or the end of Inflation) far exceeded the recent acceleration. Recent observations are consistent with a period of decreasing deceleration followed by a period of increasing acceleration, as the Standard Model predicts. Recent observations are demonstrably inconsistent with the expansion behavior you advocate. There is lots of room for innovative ideas in this field, but first you have to understand the facts.
Reply | Report Abuse | Link to thisDoppler Shift Explanation Part 1 of 4.
Reply | Report Abuse | Link to thisThe author, Tamara Davis, explains that redshift can be thought of as a photon making many tiny little Doppler shifts along its directory. Doppler shifts do not represent a true loss of photon energy, only a change of perspective.
I thought it might be helpful to explain here some aspects of the cosmological redshift in more detail, in a way that I believe is consistent with the author’s approach. Looks like I need to do this in 4 parts due to size limits.
One question that arises is why the cosmological redshift makes many tiny Doppler shifts along its trajectory, instead of one end-to-end Doppler shift when it finally impacts the observer. The amount of redshift would be very different if calculated as a single end-to-end event.
The answer lies in the fact that the photon is constrained to maintain a local velocity of c in every region it passes through. As it travels ever farther away from the emitting galaxy, the photon passes through regions of progressively faster Hubble recession velocity [H x D, where H is the universal Hubble rate] relative to the emitter’s reference frame. Recession velocity increases in exact proportion to proper distance.
Consequently, the photon’s proper velocity relative to the emitter must incrementally increase by the same amount as the change in recession velocity between each tiny region it exits and each new region it enters. So the photon’s proper velocity is always changing. Each tiny increment of proper velocity change results in another increment of redshift. The accumulation of all these increments is the final redshift at the ultimate observer.
Doppler Shift Explanation Part 2 of 4.
Reply | Report Abuse | Link to thisIncremental Doppler shifts can be thought of as momentum decay that is actually required by energy conservation. As I described, the photon gains proper velocity relative to the emitter along its trajectory. For the photon to avoid gaining energy relative to the emitter's reference frame, its momentum must decay by the same ratio as its proper velocity increases. Momentum decay is the same thing as redshift. The photon's energy, relative to the emitter's reference frame, can be calculated as its [momentum x proper velocity]. From that perspective, the redshift causes photon energy to be strictly conserved. Although energy is normally calculated as [momentum x c], this provides only a localized energy figure, not one that relates back to the emission frame. Ms. Davis has taught us elsewhere that proper velocity, such as the Hubble velocity, can be validly defined across large distances in curved spacetime, and without special relativistic corrections, even when the proper velocity exceeds c.
This description shows that the redshift occurs mostly as a function of location, not of time. Location - that is, proper distance traveled from the emitter - dictates increasing proper velocity, which in turn dictates decaying momentum to conserve energy. (The Hubble rate does change as a function of time, but historically this has mostly reduced the amount of redshift, not added to it.)
Doppler Shift Explanation - Part 3 of 4
Reply | Report Abuse | Link to thisIncremental Doppler shifts also can be thought of as a physical stretching of the light waves themselves. Light’s wavelength is defined by the proper distance between successive wave crests of traveling light. In a train of wave crests, the first crest’s proper velocity away from the emitter is always just slightly faster than the second crest’s, because at each instant the first crest is always slightly farther away from the emitter than the second crest. Therefore the recession velocity relative to the emitter that the first crest must match with a local velocity of c is contemporaneously always faster than the recession velocity the second crest is required to match. And so on for subsequent wave crests.
It's like a line of evenly-spaced joggers following each other at a constant peculiar velocity over a series of moving sidewalks moving in the direction the joggers are running -- with each successive sidewalk moving slightly faster than the prior one. The line of joggers will progressively stretch apart. Note that this effect does not depend on any paradigm of stretching space -- the sidewalks do not stretch. Note that the radial distance between photons also increases in the same proportion as their wavelength, and for the same reason. Ms. Davis has noted that effect in some of her publications.
Doppler Shift Explanation - Part 4 of 4
Reply | Report Abuse | Link to thisMathematically, the incremental Doppler shifts are multiplied together to calculate the total redshift. The equation for this is the multiplicative series (1+H(t1)dt(1)(1+H(t2)dt(2)...(1+H(tObservation)dt(Observation). (This equation uses increments of light travel time (dt) instead of light travel distance (dD) because it is calculated more directly, and the two are identical when units of c and light years are used.)
It is easy to demonstrate that this equation is mathematically identical to the equation for calculating redshift based on the proportion by which the scale factor of the universe has expanded during the photon’s journey. The latter equation is used to support the alternate theory that redshift is caused by stretching space. The fact that the two equations give the same answer demonstrates that observations and math do not provide a basis for preferring one of these paradigms over the other.
It is interesting to note that the Doppler shift formula is in the same form as the classical (non-relativistic) Doppler shift formula for a stationary observer. This shows that the cosmological Doppler shift, when calculated in the FLRW coordinate system, does not include any element of special relativistic time dilation. This is because of a characteristic unique to the FLRW metric -- no time dilation occurs between comovers despite their potentially large recession velocities relative to each other. The clocks of all comovers run at the same rate and record the same elapsed time since the Big Bang. Many cosmologists are inclined to think that an equation that does not include the effects of special relativity is flawed. They may prefer to think of this equation as a special relativistic Doppler shift, but with the time dilation element eliminated due to the use of FLRW coordinates. The time dilation is the only difference between the classical and special relativistic Doppler shifts. Time dilation would appear in the equation if a different metric were used, such as the Schwarzschild metric.
Doppler Shift Explanation - Addendum
Reply | Report Abuse | Link to thisDoes the cosmic gravitational field contribute to the redshift? When FLRW coordinates are used, gravity plays only an indirect role: it acts to reduce the Hubble rate over time. (And since dark energy became dominant over gravity in the universe, the Hubble rate is now increasing, as the expansion accelerates.) A decreasing Hubble rate decreases the redshift, and an increasing Hubble rate increases it. Here’s a helpful way to think about why gravity causes redshift only through its effect on the Hubble rate. Gravity increases the photon’s proper velocity toward the observer; but it also decreases the recession velocity of the galaxies the photon passes along its trajectory, by the same ratio. As a result, the photon loses no additional momentum beyond what the Doppler equation already calculates, and the wavelength is not further stretched. Therefore no separate factor for gravity is required or allowed in FLRW coordinates.
Gravitational time dilation can cause redshift or blueshift. But keep in mind that gravitational time dilation occurs only as a result of a clock rate difference between an emitter and observer, not just because the photon gains or loses energy due to the gravitational ‘pull’. Since the clocks of all comovers run at the same rate in the FLRW metric, there is no opportunity for gravitational time dilation for a photon moving between them. However, if Schwarzschild coordinates are used instead of FLRW, gravitational time dilation does appear as a discrement element in the redshift formula.
jonmtkisco - Unfortunately you haven't responded to the specific issues I've raised.
Reply | Report Abuse | Link to thisI’ve not been surveying all the research literature but focusing my attention on research that originally concluded that the expansion of the universe is accelerating, “Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant”,
http://arxiv.org/abs/astro-ph/9805201v1
Perhaps this would assist you to explain the specific errors in my assertions rather than simply generally protest my ignorance. I’d be happy to finally understand the errors in my assessment.
It concluded that universal expansion began accelerating about 5G years ago because of its two groups of SN observations, the nearer galaxies, which did not exhibit the distance estimation discrepancies, were clustered at a distance of about 5Glya.
Alternatively, the standard cosmological models used to estimated the distance to the galaxies in which type Ia SN were observed may be only correct for light emitted in the past 5G years, since the universal conditions presumed have only existed for about 5G years.
That alternative, while it may seem critical of astrophysics, does not require an unidentified type of energy to produce sudden acceleration of the entire universe. The far less extraordinary explanation attributed to human error should be eliminated before unidentified universal energies are presumed to physically exist.
It is important to realize that the distance estimations of standard cosmological models for objects more than about 5Glya had never before been verified using independent measurement methods: they could only have been presumed to be correct. It has now been observationally determined that they were not correct for those distances.
Reply | Report Abuse | Link to thisPerhaps no has explained any of these theories to a photon.
Reply | Report Abuse | Link to thisPlease, think about this:
Reply | Report Abuse | Link to thisIf Universe is expanding, the light from far galaxies travel in a logaritmic curve.
For simplicity imagine a circle expanding. From each point of the circle begin two beans of light. The light travel to c velocity, and the curve grow, so fast as the universe is expanding. So, the light bean travel in a log curve, in each point of his travel the angle of the bean with the expansion of the circle is constant.
Another view: All the beans of light that we can see, travel from his source trought a log curve. The same log curve.
If expansion of universe is constant, if light velocity is constant, the time is NOT constant. This is because the Doppler efect give us the mistake idea that univers is expanding more fast.
Error: The expansion is constant. c is constant, but in a log curve will be us mistake.
Sorry for my BAD and MAD english.
This effect is entirely within the construct of an expanading Universe, as the energy is diisipated over a larger distance and longer period.
Reply | Report Abuse | Link to thisEnitrely compatible with advanced quantum gravity and harmonic quintessence. See Strinq quintessence and the formulation of advanced quantum gravity. Physics Essays 22:364-377. The formulation of harmonic quintessnece and a fundamental energy equivalence equation Physics Essays 23: 311-319
Consider my intuitive theory that the expanding universe is simply following the basic physical laws of gravity and accelerating towards a larger mass. Where would that mass come from?
Reply | Report Abuse | Link to thisWhy do we assume there was one Big bang? What if there were and are multiple Big Bangs all originating from the same point (Event Horizon). Consider each event happening at relative intervals that are billions of years apart.
If one were to observe the very first event, there would be the classic theory of a beginning Event Horizon (Singularity). This point would explode energy and mass into the void, which would then generally expand out along the lines of the inflating balloon.
Following basic laws of gravity, the total mass would eventually slow down and then start contracting back towards the original Event Horizon. Now we consider the second Big Bang. It follows the path of the first event but somewhere in time the mass of the second event (E2) runs into the mass of the returning first event (E1). The second event mass (EM2) continues through the first event mass (EM-1) but is minutely slowed by their mutual gravities. EM-2 goes out to a slightly shorter turn-around -point (TAP) and heads back to the original Event Horizon.
As each successive event occurs, at huge time intervals, the process is repeated.
Over an exceptionally vast amount of time, the intuitive result would be multiple collapsing balloons of mass and energy returning to the original Event Horizon.
Since the TAP would become shorter with each passing EM, eventually, the outgoing EMs will effectively start to merge with the outer EM balloons . Their combined mass will then accelerate their collapsing speed. As the following EMs come through the larger mass, those TAPs will be shortened again and the entire process is accelerated to another degree.
The EMs coming back would accelerate and level off to just under e .
Could it be that there is a humungus balloon of matter and energy collapsing towards us at near e velocity? Would such a vast gravitational field account for the outward acceleration of our observable universe? Could the fact that this acceleration started at a particular point in time imply the edge of the gravitational field reached our neighborhood 5 billion years ago?
What would the math look like? If everything is happening in the billions of light years, can this be disproved empirically? Mathematically?
I shouldn't be typing these things without my glasses. Please amend my previous post where it I put in "e". That should read "c" for the speed of light. Sorry for the gaff.
Reply | Report Abuse | Link to thisMas Libertad - I don't do math or physics, but I agree that if light (or spacetime, if you insist) curves, in conjunction with its independent linear velocity, when obliquely traversing the gravitational field of a sufficiently massive object, it may also curve when obliquely traversing the expanding universe.
Reply | Report Abuse | Link to thisWhile the conventional perspective is that spacetime expansion is omnidirected, I think this is an effect that can be produced by directional expansion from a singular focal point. If the universe were, for example, radially expanding from a singularity, spacetime would also be incidentally expanding laterally. As a result, all objects would appear to be omnidirectionally receding away from any included observer even thought the force producing expansion was solely radially directed.
Since light is independently radially directed away from its emission source, in a radially expanding universe most light must be obliquely directed relative to the immediate direction of expansion. This should produce a slight curvature to most light, aligned with the direction of expansion. As the universe expands the incidental lateral direction of expansion may reduce the effective curvature.
If redshift is considered to be the linear expansion of light’s wavelength by directionally aligned expansion of spacetime, to the extent that, in the early universe, light is not aligned with the local direction of expansion, it may be curved without incurring wavelength extension. This alternative affect of expansion in the conditions of the early universe could account for the observed greater distance traversed by ancient light emissions as a function of their redshift.
Eureka999 - I agree, as stated in comment #2:
Reply | Report Abuse | Link to this"The simple answer is that the universe is expanding, dispersing its energy throughout space and time. Universal mass-energy density is decreasing, but it is being conserved..."
However, I can't comment on the uncomprehended string theory.
Antineutrinos have different masses then neutrinos and dispute the special theory of relativity because charge, parity, and time symmetry is broken with neutrinos morphing into either an electron, muon, or tau. Mohapatra says a new fundamental direction of thinking about subatomic particles and the origin of matter is required. All forces of nature are streaming waves/particles and black hole entangled spins cause gravity to be instantaneous over great distances. dark matter is wormholes of white holes not mini-black holes or they would interact with normal matter.
Reply | Report Abuse | Link to thisIt's not leaking energy if you define the system boundaries as expanding at the speed of light.
Reply | Report Abuse | Link to thisjtdwyer: I see our Universe spanding trought a Fourth dimension. We hav'nt experience in think in 4D. It is the reason for put a sample more easy to understand.
Reply | Report Abuse | Link to thisImagine a lake. The surface is a brane of 2D.
In the middle of the lake fall a stone generating a wave. The wave is a circle, a space of 1D expanding trought the 2D brane.
If in the wave live several flies, they travel making surf in the wave. All the surfers see that the others run away. The more far run out more speed. So, the galaxies run away from us. The more far, run more speed.
The wave grow at velocity 2*PI*v (v=velocity of expansion of the wave in the surface of water)
Our Universe grow at velocity 2*PI*V (V=Velocity of expansion of Universe in the 4th dimension of space)
In a wave, a surfer can travel to left or to right. So, the movement of surfer, if constant, is a log curve (or log spiral).
In our universe, the max velocity is c (light velocity). All the light beans make a trayectory log spiral, but not in our universe. In our 3D universe the trayectory is right, but in the brane 4D is a log spiral.
Sorry, I write very bad english and I can't explain better, but I think I am in the right.
The fall of a Stone in the middle of the lake is like the Big-Bang, a perturbation in a Brane of 4D that generate a wave of 3D travel trought a brane of 4D.
We can't see trought the 4D, but can see the effects of the expansion of our universe. A universe that grow at constant velocity and is (2 * PI * 13.700 MM yl) 96.000 MM yl width, where galaxies are more and more far and the light shift to red, but not proportionaly to distance from the source, but proportionaly to lenght of trayectory log-spiral of the light from far galaxies to our eyes.
Addendum:
Reply | Report Abuse | Link to thisand the 4th dimension is NOT the time.
I Think that Universe is NINE or TEN dimensions, and the Time is'nt one of they.
Another addendum:
The shitft to red deppends of the lenght of the trayectory log-spiral of the light bean. No matter if in his way travel gravitacional fields or wide space.
Regards.
Mas Libertad - You may be right, but I'm just a simple old guy happy to live in four dimensions (described by others). Even in my simple universe, light emitted into the conditions of the early universe is likely curved over great distances. So, we do agree on at least one thing. Good luck!
Reply | Report Abuse | Link to thisI was disappoited with Dr Davis' article because she seemed to be stretching her explanation to fit the assumption that the law of the Conservation of Energy and Matter were absolutely true.
Reply | Report Abuse | Link to thisIf it is absolutely true, then there should currently be no energy, no matter and no univesrr to leak.
There is increasing evidence in quantum physics that there are non-material phenomena in our universe. Perhaps these anomolies she is presenting are clues to how the universe happened.
All of this this assumes that the red shift measured is due to an expanding universe. The alternative idea was that intervening hydrogen molecules absorb the energy from the photons. The further away the more energy absorbed the more the redshift. etc. Hence the universe is not expanding!
Reply | Report Abuse | Link to thisUnfortunately molecular hydrogen is very difficult to detect in the densities found in extra galactic space.
If this were the case then the energy would not be lost but may contribute to the microwave background radiation that is attributed to teh remnant bigbang.
I really have a problem with the big bang theory.
THE IMPRTANT THINGS IS THAT WE SHOULD KNOW THERE IS A ONE POWER THAT CONTROL THE ALL UNIVERSAL ENERGY AND MOVEMENT.
Reply | Report Abuse | Link to thisWilliam J - The hypothesis you're suggesting states that sparse molecular hydrogen, at indeterminable densities, absorbs and reemits all intergalactic light?
Reply | Report Abuse | Link to thisDoesn't it seem highly unlikely that intergalactic light would 'hit' a single atom 'suspended' in 'empty' space? If extragalactic molecular hydrogen densities were dense enough to significantly influence light's spectra wouldn't it be easily detectable?
Interesting idea.
Reply | Report Abuse | Link to thisI thought the intergalatic space was filled with almost undetectable hydrogen molecules which absorb the energy of the photons as they pass through. The further away the more the energy loss etc. Hence the universe is not expanding.
Either way the big bang seems a wrong headed theory.
heighway – stated:
Reply | Report Abuse | Link to this“It is concluded that the function presently thought to describe the expansion of space itself, actually describes the evolution of rest masses, which increase with time. Since emission frequencies are directly proportional to the electron rest mass, the red shift is seen to be a simple consequence of the fact that rest masses were in past epochs much reduced as compared with present values. Since this effect accounts for the red shift, it is clear that the universe is not expanding.”
From this I understand heighway to mean that the emission absorption band of atomic components in observed light is shifted by the emitter's electrons’ increased mass energy over time, and that the emitted wavelength of light is not altered during the billions of years spent traversing spacetime. However, it is established by the Doppler Effect that any relative differential motion of an emitter and an observer does produce shifts in the observed wavelength of emitted light as well as other wave energy.
Additionally, if the rest masses of elementary electrons were lower in earlier epochs, they must somehow be gaining mass energy as the universe temporally develops. This produces the opposite problem of perceived energy losses: photons are not losing energy; electrons are gaining energy. Surely I’ve misunderstood something fundamental?
I fell in love with this method of inquiry in 1955, shortly after Einstein's death. I am still very much enamoured by it. Please do not ever stop publishing these excellent missives. Thank you kindly.
Reply | Report Abuse | Link to thisWhen photons have to travel great distances through space, where supposedly, there is no friction, there should not be reduction in energy content of the photons and there for no red shift. The fact that we observe red shift, means that there is loss of energy. We don't know if this loss is due to ubiquitous dark matter in the universe. I wished, the author had addressed the possible role of dark matter in her article.
Reply | Report Abuse | Link to thisdoctorpatil007 - Energy wave length extension occurs in the Doppler Effect as a result of increasing distance between emitter and observer. In the case of light traversing intergalactic spacetime, the increased distance is produced by the expansion of intervening spacetime.
Reply | Report Abuse | Link to thisThere is no evidence supporting any interaction of distant light with any kind of intervening matter: any absorption and reemission of energy by intervening matter would further alter the spectroscopy of observed emissions: it would have been emitted by whatever particles might constitute dark matter rather that its emitting stellar object. In that case we would know what dark matter is, rather than still imagining what it might could be. Of course, if dark matter emitted energy it wouldn't be dark.
I don't think the observed redshift of distant light has anything to do with any imaginary dark matter.
Thanks for your answer. So in other words, the doppler effect is what the observer perceives of the source which basically remains unchanged.
Reply | Report Abuse | Link to thisCan you give me any example, where a galactic body that is coming closer to the earth where the red shift changes to blue.
doctorpatil007 - You're welcome. I should explain that I am not an authority on the subject, I am only expressing my opinion. A good place to begin your own investigation is wikipedia:
Reply | Report Abuse | Link to thishttp://en.wikipedia.org/wiki/Main_Page
then enter 'Doppler Effect' in the search dialog box.
When the distance between an emitter and observer is decreasing during emission, energy wavelengths are compressed, shifting their spectra towards blue.
In my opinion, light from more distant objects have been subjected to greater expansion rates, but the affect of expansion on the wavelength of light is also accumulative: light from more distant objects has been subjected to greater rates of spacetime expansion as it traversed increasing distances of expanding spacetime. Both conditions increase the observed redshift of distant light.
Any local motion, resulting from galactic cluster orbits for example, are minor in relation to the large scale effective relative motion imparted by spacetime expansion.
It cannot be correct that the first thing a photon meets, after travelling across the universe for billions of years, is the mirror of a telescope. What about all the elementary particles out there in space, not to mention gravitational influences as they pass galaxies and stars, stellar winds, the effects of supernovae, dark energy, dark matter, etc?. If, as is likely, photons collide with some of these particles they must lose some energy.
Reply | Report Abuse | Link to thisAll of these factors have the potential to slow photons and induce the perceived Hubble red shift.
This means that Hubble may have been at least partially wrong in his assumption that photons always have a constant speed and can therefore be used to measure intergalactic and cosmic distances.
Surely Einstein got it right when he said that both space and time are infinitely variable!. Hence the attributes of anything in spacetime -- including a photon -- must also vary according to where it is at any particular moment.
Jaboz55
Jaboz55 - IMO, light waves emitted from a small flashlight can be propagated through the Earth's atmosphere without colliding with any atoms or molecules, but I could be wrong.
Reply | Report Abuse | Link to thisAs I understand, light that 'collides' with other matter (in space) is diffracted and is not likely to be detected in sufficient quantities to be associated with an emission source: to the extent that is is detected by a telescope it is considered to be 'scattered light'. Light that is absorbed by matter may be reemitted by its new emitter.
Given the apparent low density of even detected 'virtual particles' in interstellar space, I think that photons emitted from distant galaxies are directly detected by powerful telescopes after a sufficient exposure or collection duration.
Personally, I think that material energy moves through space as energy waves and manifest as particles only when their wave energy is converted to rest mass, halting their propagation through space at least for a quantum of time.
I agree that redshift of intergalactic light has limited usefulness as a measure of distance. I think that statement is proven by the calibration of the redshift of galactic light to type Ia supernova observed within them. Since the SN peak emission luminosity is consistent, the traversal distance of its light can be precisely derived from it observed luminosity. The discrepancy between the two methods of distance estimation for galaxies more than 5 billion light years away certainly indicates that something changed around that time.
That something that changed could have been the rate of spacetime expansion, if Hubble's establishment of redshift as a product of spacetime expansion is correct.
Without a doubt this is a very complex subject and I may be oversimplifying at some level, but I think this is a usefully accurate perspective.
BTW, that distance estimates for both type Ia SN luminosity and redshift estimation methods were comparable for light emitted in the past 5 billion years is strong evidence that redshift is produced by spacetime expansion.
Reply | Report Abuse | Link to thisNo one has addressed my question! If the balance between energy and matter is zero (0) and the Universe began from a zero (0) energy state, from whence did energy and matter come? An all or a nothing logicalpropoition needs only a single contrar examole to disprove the all or nothing part of it.
Reply | Report Abuse | Link to thisPinch yoursekf and you will feel flesh and pain. The fact that the Universe exists is more then sufficient proof that this "Law" is insufficient. A slight diversion at some remote decimal place (say the 1,000th) is sufficient to explain this discrepancy. Please stop this mathematical nonsense and get logical.
Jay Powell
"When light is redshifted by the expansion of the universe, where does its energy go? Is it lost, in violation of the conservation principle?"
Reply | Report Abuse | Link to thisNo.
From the reference frame of the origin, the light is not redshifted; it's only our relative velocity to the source that modifies the light (or, more accurately, it's the velocity of the source that partially produces the initial frequency of the light, and our velocity that colors our perception of that initial frequency).
This difference in perspective is *exactly* what relativity implies. Because we're moving away from the source of the light, it has less energy relative to us. Kind of like a baseball: if someone throws a baseball at you, if you're moving away from them, it has less energy than if you're running toward them. It's the same with light, except that light doesn't have the luxury of moving faster or slower relative to you; it has to change its frequency instead.
The Universe is, indeed, "leaking energy", but not all of it - only the part that contains Mass. If we acccept the "Standard Model" we have a universe which has been expanding for some 13.4 Billion years at something less than the speed of Light. However, some 380,000 years after the universe came into existence the stage calle "Recombination" de-coupled Mass from Electro-Magnetic energy and allowed ELectromagnetic Radiation to escape the Mass. Since the Mass has been expanding ever since at LESS than the speed of Light, but Electromagnetic Radiation travells AT the speed of Light, it follows that the Universe is comprised of TWO SPHERES. One sphere, the inner sphere, consists of all the Energy and Mass still remaining (and expanding at LESS than the speed of Light). With another, vastly larger sphere, consisting only of the Electro-Magnetic energy (and NO MASS) which has been expanding AT THE SPEED OF LIGHT ever since de-coupling.
Reply | Report Abuse | Link to thisTo put it another way. If we define "The Universe" as "everything that came into existence at the moment of the Big Bang" then THAT universe is NOT "losing energy". If, on the other hand, you define "The Universe" as that which contains all the MATTER in the Universe. Then THAT Universe, IS losing energy.
(On a side note, I have often wondered if all the phisical "Laws" which we know of would still be valid in the region where only the expanding sphere of electro-magnetic energy exists?)
Doug Maitland,
Lincoln, Nebraska
Jay Powell - Nobody knows.
Reply | Report Abuse | Link to thisSo the article implies that enregy is equal to E=hy x the inverse of the Hubble constant. The difficult part is finding the age of the photon. They might lie a bit. Has any one ever given thought of the fact the light is red shifted is due to our being in an area of space that is contracting? Perhaps the whole universe is contracting. How would we know the difference?
Reply | Report Abuse | Link to thisQuantumDyslexia - As I understand, one of the fundamental assumptions of cosmology is that the universe is homogenous. While the galaxies in our local group may be converging as a result of localized gravitational effects, it is presumed that locally and universally, spacetime is expanding at a temporally consisitent rate as a result of the universal release of initial energy during the big bang. Without any assistance from the hypothesized dark energy, it is expected that the rate of expansion will temporally diminish as a result of the initial energy's dispersal throughout expanded spacetime.
Reply | Report Abuse | Link to thisI think that the redshift of observed light must indicate the total wavelength extension incurred by the temporally varying expansion of spacetime traversed. Since light is independently directed through curved expanding spacetime, it may traverse varying distances at varying rates of expansion. As a result, light of similar emission ages may exhibit somewhat varying amounts of redshift.
Calibration of redshift to precise diminishment of type Ia supernovae peak emission luminosity verified the light traversal distance estimates for light emitted during the past 5 billion years (although redshift calibration failed for more ancient light emissions).
IMO, since photons only materialize when light waves are detected the term 'photon age' is not technically relevant, although light emission age conveys the intended information.
According to the US Energy Information Administration Illinois has the most uclear plants and over 90 Mega Watts of output in 2008. That totally contradicts leading statement of The dirty Truth. You better explain yourself carefully adn fast to All readers.
Reply | Report Abuse | Link to thisEver think about allowing an amitaure article? I would like to submit one for review. Warren York, psientific@charter.net
Reply | Report Abuse | Link to thisI first conversed on this subject some thirty years ago and hope to offer a little insight:
Reply | Report Abuse | Link to thisAs the photon moves through space, it is surrounded by mass on all sides. Each local unit of mass would have its own gravitational bond to the photon while in its local gravitational field. As the photon passes large gravitational sources and approaches other large gravitational sources one would expect to see a red shift that is offset by a blue shift caused by the gravitational source it approaches. However as a photon passes outside the vast majority of mass in the universe as it moves from a dense area to a less dense area (due to the different speeds of recession of matter vs light), there is less matter in front than behind and a larger red shift per unit of distance would be assumed. Assuming a massive collection of matter from the big bang (BB), expanding uniformly at less than c with photons expanding equal to c it can be assumed that the mass of the big bang is surrounded by the photons of the same event. There must be a central BB mass surrounded by particles of increasing speed ending with a photon shell. Therefore the collective gravity of all the mass of the BB will be acting upon the photons that have surpassed in distance the massive portion of the BB. One then must consider the effect of the mass of the entire universe on each single photon located distant from the gravitational center. One can not simply assume that the identical effect will occur as that found with the interaction of mass and its effect on red shift within the mass of the BB because within that mass, gravity is both increasing its red shift and blue shift simultaneously depending on the location of the photon. One would expect some sort of different application of gravity when viewed as being dependent on the whole mass of the universe acting on the mass/energy of a single photon. One would expect within the central mass that each unit of gravity would reinforce each other. And one could surmise that outside the central mass of the BB the gravitational force would be exceedingly grand when applied to a single photon exiting the central mass of the BB.
One could assume that the entire mass and gravitational force of the universe applied to a photon would bring its wavelength to become essentially flat or infinite. In effect energy has been expended over distance leaving behind potential energy in what form I do not know. This expended energy source could be the creative mass comprising dark matter and the bond between energy and mass.
manofmetal - I haven't been thinking about this for long, but I think your statement:
Reply | Report Abuse | Link to this"However as a photon passes outside the vast majority of mass in the universe as it moves from a dense area to a less dense area (due to the different speeds of recession of matter vs light), there is less matter in front than behind and a larger red shift per unit of distance would be assumed."
...can be more simply stated as: the expansion of spacetime imparts an increase in the distance light traverses, extending its wavelength. The energy loss is not expended by the light but by spacetime itself: its energy is expended in its expansion and dispersal. It is time-distance itself that is changed.
Even ignoring gravitational effects, the density of matter in the early universe would seem to argue against complete transparency for early light emissions traversing spacetime unimpeded until we now detect them. In the expanding universe the density of mass diminishes and the effect of gravitation also diminishes with distance. The big questions revolve around light in the early universe...
Of course your perspective may more correct - I'm just guessing...
jtdwyer said: "the expansion of space time imparts an increase in the distance light traverses, extending its wavelength"
Reply | Report Abuse | Link to thisWhy would an increase in the distance light travels or the composition or formation/expansion of space time extend its wavelength ? It is accepted that gravitation impacts wavelength and that is sufficient to support the theory I mention. There is no need for an unknown force or additional theory.
manofmetal - Did I mention that I'm a pretty good guesser?
Reply | Report Abuse | Link to thisAccording to Wikipedia, redshifts are attributable to three different physical effects: the Doppler Effect, Cosmological Redshift and Gravitational Redshift.
http://en.wikipedia.org/wiki/Redshift
The effect of gravitation diminishes precipitously at intergalactic spacetime scales of distance, yet as I understand the relationship between the distance traversed in expanding spacetime and the redshift of distant light is highly predictable. I don't think these effects are attributable to gravitational redshift.
You are correct to question my independent, unsubstantiated assertions, but you should also check your own sources.
Jay, please release your preconceived notions for a moment and think a little "black hole" and Big Bang (BB) convergence.
Reply | Report Abuse | Link to thisThe path: Your an observer outside our universe as the expansion of the universe progresses. You see that post BB the universe has condensed and expanded such that there is a more dense mass and a less dense mass due to the fact that light escaping the BB is faster than mass escaping the BB. In effect there is a massive spherical portion with high gravitational force due to the mass and a less dense area comprised of photons and particles.
Hence: One must admit that the gravity of the entire universe "reaches out" through space and interacts with the photons and particles in the outer sphere. Imagine now that a string of gravity (or wave) is able to interact with a photon in such a manner that the photon in the outter sphere is red shifted such that the length of the wave is essentially flat. At that point the photon would have 0 energy and could be described as "the photon that expended all its energy over the distance A,B in the time x light years. The gravitational force could likewise be said to have expended its force (though possibly not all) over the same distance A,B. Imagine now what must exist along the path that photon took to reach its current state. (Dark Matter?) Along that path would be the remnants of the gravitational force and the energy of the photon. In effect the energy/mass of the photon and the force of gravity sufficient to balance the complete mass/energy dissipation exists along this path.
One only need "assume" that there is a propensity for energy/mass/gravity/time to exist to reach the next conclusion. That conclusion would be that the Dark Matter that comprises the path of the depleted photon can re-condense into matter again, in a reverse big bang powered by the residual mass/energy/gravity/time (megt) that could have a propensity to exist. Lets assume at some point all the mass of the universe decays into particles and photons that go through this process. We would then have a universe comprised of nothing but dark matter with "0" net energy, "0" time line and a propensity to exist.
With 0 time expended the "megt" would simply remain stable until it re-condenses into another BB. Like our current imagined vision of Dark Matter the megt would possess great mass, though, like a black hole it would be difficult to detect except by the loss of radiation and the apparent disappearance of mass. In effect one could say that the megt would be what is "outside" the universe.
Jay, please release your preconceived notions for a moment and think a little "black hole" and Big Bang (BB) convergence.
Reply | Report Abuse | Link to thisThe path: Your an observer outside our universe as the expansion of the universe progresses. You see that post BB the universe has condensed and expanded such that there is a more dense mass and a less dense mass due to the fact that light escaping the BB is faster than mass escaping the BB. In effect there is a massive spherical portion with high gravitational force due to the mass and a less dense area comprised of photons and particles.
Hence: One must admit that the gravity of the entire universe "reaches out" through space and interacts with the photons and particles in the outer sphere. Imagine now that a string of gravity (or wave) is able to interact with a photon in such a manner that the photon in the outter sphere is red shifted such that the length of the wave is essentially flat. At that point the photon would have 0 energy and could be described as "the photon that expended all its energy over the distance A,B in the time x light years. The gravitational force could likewise be said to have expended its force (though possibly not all) over the same distance A,B. Imagine now what must exist along the path that photon took to reach its current state. (Dark Matter?) Along that path would be the remnants of the gravitational force and the energy of the photon. In effect the energy/mass of the photon and the force of gravity sufficient to balance the complete mass/energy dissipation exists along this path.
One only need "assume" that there is a propensity for energy/mass/gravity/time to exist to reach the next conclusion. That conclusion would be that the Dark Matter that comprises the path of the depleted photon can re-condense into matter again, in a reverse big bang powered by the residual mass/energy/gravity/time (megt) that could have a propensity to exist. Lets assume at some point all the mass of the universe decays into particles and photons that go through this process. We would then have a universe comprised of nothing but dark matter with "0" net energy, "0" time line and a propensity to exist.
With 0 time expended the "megt" would simply remain stable until it re-condenses into another BB. Like our current imagined vision of Dark Matter the megt would possess great mass, though, like a black hole it would be difficult to detect except by the loss of radiation and the apparent disappearance of mass. In effect one could say that the megt would be what is "outside" the universe.
jtdwyer said
Reply | Report Abuse | Link to this"in the distance light traverses, extending its wavelength"
" redshifts are attributable to three different physical effects: the Doppler Effect, Cosmological Redshift and Gravitational Redshift."
manofmetal said:
"Why would an increase in the distance light travels or the composition or formation/expansion of space time extend its wavelength ?"
I don't deny cosmological redshift, I only deny that distance traveled causes redshift. Sorry for the confustion.
I don't believe it is the composition or formation of space time that extends wavelength, I believe it is the "perception" of a redshift that may not really exist due to a co moving frame of reference. Does the perception of a redshift because of our motion equal a redshift when we are in the same frame of reference as the photon.
manofmetal - I have to view things simply, and I don't do math. As I understand, at cosmological scales the observed redshift of light is considered to be linearly related to distance traversed. Some astrophysicists like to illustrate the effect with a Slinky: spacetime expansion continuously increases the distance between objects (relative locations), including (virtual, undetected) photons representing light waves dispersed throughout spacetime. At least that describes my working conception.
Reply | Report Abuse | Link to thisI also have my own ideas regarding the original 'discovery' of dark matter. I'll simply refer you to my essay posted at:
http://www.sciencewithoutfiction.com/uploads/Mass_Distribution-_Galaxy_Rotation_Problem.pdf
The extension of the slinky represents the expansion of the cosmos, not the distance a photon travels. And the cosmological implications do not apply within a solar system. So light traveling from the sun to the earth is not influenced by the cosmological red shift even though it is a longer distance than light traveling from the moon to the earth. Distance is not the determining factor.
Reply | Report Abuse | Link to thisHere is a good explantion as it relates to distance and energy loss of a photon. The original theory was called the "tired light" theory and was based on light red shifting due to loss of energy over distance. http://en.wikipedia.org/wiki/Tired_light
Reply | Report Abuse | Link to thismanofmetal - I thought this discussion was in response to the question:
Reply | Report Abuse | Link to this"When light is redshifted by the expansion of the universe, where does its energy go? Is it lost, in violation of the conservation principle?"
I certainly agree that all I've said does not apply to intragalactic light emissions. Sorry for that confusion.
Thanks very much for the 'tired light' reference - I wasn't familiar with that early proposal, which has now been generally dismissed by astrophysicists, correct?
In the form of an cosmological explanation of the background radiation and certain other phenomena it is not the preferred theory. It is important to note that certain aspects of the theory are applicable under limited conditions. Read the wiki reference in detail and the arguments that disprove the cosmological aspects and you will see that most of the theory is not applicable. However you will also see that some aspects are not in dispute. Regardless tired light fails.
Reply | Report Abuse | Link to thisI have a sense of incongruity towards dark things. A clean universe is needed now. Dark things are like the Aether of older days. The most famous Alternative is "Modified Gravitational Theory as an Alternative to Dark
Reply | Report Abuse | Link to thisEnergy and Dark Matter by J. W. Moffat". He is studying the nonsymmetric gravitational theory (NGT). The "3D"-nonsymmetric gravity may be the key. I imagine the two dimensional galaxy.
http://www.geocities.jp/imyfujita/galaxy/galaxy01.html
Thank you.
imyfujita - I strongly agree with your sentiments about dark theories presented as a proxy for actual physical processes.
Reply | Report Abuse | Link to thisMy difficulty with the dark matter hypothesis is that, as you stated, it was expected that the inverse-squares law would apply to stars independently orbiting a central galactic mass, "just like planets orbit the Sun" (Vera Rubin).
However, the Newtonian gravitational equation applies only to a two-body gravitational problem. In the Solar system, since 98% of total mass resides within the Sun, all planetary orbits can be estimated as a two-body problem: all planets are effectively independently orbiting the Sun.
IMO, stars within the galactic disc of spiral galaxies do not independently orbit any central mass: they are loosely bound to effective form a rotating singular object of mass.
Your two dimensional galaxy solution may be correct, but it seems to me to accept the presumption that the inverse-squares law applies to individual stars in the galactic disc of spiral galaxies. I have difficulty with this. I am also incapable of evaluating the mathematics. Sorry, but I cannot adequately evaluate your proposal.
Just in case you missed my essay, please refer to:
http://www.sciencewithoutfiction.com/uploads /Mass_Distribution-_Galaxy_Rotation_Problem.pdf
Thanks.
As far as I know light has no mass, if so how it loses something it does not already have. if space has mass why cant we measure it? If space has no mass how can we say it is expanding?
Reply | Report Abuse | Link to thisgesimsek - As I understand, photon (detected light) particles are considered to have zero rest mass, although I think they can be considered to have some small effective mass when in motion (as light waves). I'm not a physicist and can't explain very well (as far as I know, no one may really understand it very well).
Reply | Report Abuse | Link to thisI'd explain the expansion of spacetime as the expansion of the dimensional space in which galaxies reside: the distances between galaxies is increasing.
If you haven't already, I'd suggest going to Wikipedia, the free online dictionary, and searching for terms like 'spacetime'.
if light had any mass it should have been infinite at maximum speed according to relativity, I think.
Reply | Report Abuse | Link to thisgesimsek - That's correct, but only if it had non-zero rest mass, as I understand. Rest mass is generally considered to be 'Mass'.
Reply | Report Abuse | Link to thisI get fuzzy on this part, but I think that the term 'effective mass' applies to matter in motion, like momentum or something... This might be a good opportunity for you to check with Wikipedia: search for 'rest mass' and 'effective mass'...
It was an interesting article and, as the discussion here indicates, quite a topic!
Reply | Report Abuse | Link to thisI noticed that the author plays ultimate, whih I
It was an interesting article and, as the discussion here indicates, quite a topic!
Reply | Report Abuse | Link to thisI noticed in the print edition bio of the author that she plays ultimate. (I noticed, because I do as well.) But I have to say "tsk tsk" to the editors!!! The print edition uses WHAM-O's trademark... without capitalization or attribution. This is why the sport is called "ultimate disk" and not "ultimate fr.....".
Sorry -- should have been "ultimate disc." But at least I did not violate anyone's trademark!
Reply | Report Abuse | Link to thisi think photon's effective mass cannot be bigger than its rest mass otherwise it would go faster than light, which contradicts relativity.
Reply | Report Abuse | Link to thisgesimsek - Thanks for being insistent and making me look. It's of course much more complex subject than I have been presuming in my discussions as a lame layman. Please see:
Reply | Report Abuse | Link to thishttp://en.wikipedia.org/wiki/mass
http://en.wikipedia.org/wiki/Rest_mass
In the first reference it is stated:
"In special relativity, relativistic mass is a formalism which accounts for relativistic effects by having the mass increase with velocity." Beyond that I cannot justify any of my prior statements regarding relativistic mass.
An object with non-zero rest mass cannot be accelerated to the speed of light because its mass is increased by acceleration, increasing the amount of force required to overcome its current inertia to accelerate to a higher velocity at greater momentum, if I haven't misrepresented the processes in effect too much.
Somewhere I had become confused about effective mass, which seems to apply only to solid state electronics.
I have to repeat that I'm not a physicist and can't do math. However, as I understand, classically, mass generally relates to an object's energy at rest (often imprecisely considered its weight), which is also involved in assessing its inertia, and momentum as force is applied.
As I understand, a photon's total energy upon detection includes its momentum, which provides for the Photovoltaic Effect (transferring its energy to an electron (system), producing work)... But I tend to think in general, rather conceptual terms.
I hope this helps somewhat more than it confuses: I recommend that you refer to a more authoritative source for further clarification. Thanks for helping me to clarify my own improper generalizations.
If I look at a weak gravitational system, I can propose that the energy of a photon emitted by an atom, is
Reply | Report Abuse | Link to thisE=mgH + h(change in frequency)
As the photon gains altitude (H) the frequency drops and in that sense the energy of the photon has decreased. However, it has gained energy due to its position. If it is absorbed at altitude H by a different atom and re-emitted back to its source of origin in our simple system, it would return to the original frequency that it had when it started. Hence, in this sense energy is conserved.
I dont think we should worry much about energy and mass equations. Currently scientists cannot explain where the mass of particles come from and they just assume it in their formulas. Even in cosmic scale they say there is an expansion due to a dark energy, which is yet to be observed. I wont be suprised if they finally say all is virtual and there are just laws but no matter.
Reply | Report Abuse | Link to thisgesimsek - If astrophysics community ever generally recognizes that the requirements for dark matter and dark energy were generated by widely accepted gross misinterpretations of observational data, cosmologists won't feel so comfortable with their models again for quite some time. However, the alternative: continuing the current delusional state, is, in the long term, even more damaging to the credibility of science.
Reply | Report Abuse | Link to thisThe long established laws of physics aren't perfect or complete, but they are far more dependable than the apparent consensus conceptions of astrophysicists.
Our spacetime continuum is the central proton of an identical larger-scale continuum, and so ad infinitum. So, the energy leakage into the smaller-scale continuum is precisely offset by the energy influx from the larger-scale continuum.
Reply | Report Abuse | Link to thisRead more: http://eschatopaedia.webs.com/electronandproton.htm
See also: http://2012wiki.com/index.php?title=The_End_of_the_World
Our spacetime continuum is the central proton of an identical larger-scale continuum, and so ad infinitum. So, the energy leakage into the smaller-scale continuum is precisely offset by the anergy inflow from the larger-scale continuum. This means that despite the energy leakage from our universe, its total energy is conserved.
Reply | Report Abuse | Link to thisRead more: http://eschatopaedia.webs.com/electronandproton.htm
See also: http://2012wiki.com/index.php?title=The_End_of_the_World
Rather than attempting an explanation in this venue, I propose that you send me your email address so that I can send the entire section of my book on cosmology to you as a PDF file.
Reply | Report Abuse | Link to thisTo maintain privacy, google my name, 'Jack Heighway' - The first item will be the website for my book. Click on 'contact' , enter your email address and I'll send the file to you.
I think Dr.Davis and her colleagues need to be more consistant in illustrating the red shift phenomena. She (or the SA artist) shows a continuous wave going from the police car to the observer. On the next page the illustration shows light as a point photon traveling in spacetime. Both examples are highly misleading. EM radiation travels as quanta of energy not as a continuous wave. To accept continuity would mean having to re-adopt the ether as a medium of transmission. But a quanta of light of nanometer "wavelength" would be an incredibly small bundle of energy and to suggest that a radar gun or other sensor can parse out a shift in a nanometer sized particle bouncing off a car or any other object moving in spacetime is almost ludicrous. However, radar guns work and stars or galaxies do red-shift. Intelligent lay-persons require physicists to re-think the whole concept of EM transmission and come up with a more acceptable and consistant explanation of the red-shift.
Reply | Report Abuse | Link to thisNot to attempt to address all you issues, I would point out that radar guns, for example, do not just emit a quantum of EM radiation but, for a specific interval, continuously emit EM radiation. I agree that light cannot be a continuous wave occupying the the separation distance between the emission source and eventual observer, I think a beam of light or EM wave could occupy the spacetime traversed for the duration of continuous emission.
Reply | Report Abuse | Link to thisIMO, when interacting with matter of sufficient mass to absorb the light's momentum, light's material energy is manifested as photons, quantisized particles of material energy, until all emitted energy directed to the detector has been absorbed.
Modifying my previous statement: "I agree that light cannot be a continuous wave occupying the the separation distance between the emission source and eventual observer..."; I think that in the example of a radar gun continuously transmitting, the EM signal can fill the space from the transmitter to the reflector and back to the receiver.
Reply | Report Abuse | Link to thisHowever, this only occurs for a 'continuous' transmission. I the case of a supernova explosion, the EM wave generated must permeate spacetime, radiating from the imploded star, until the emission ceases. From the perspective of an observer on Earth, the light would be seen as the sudden appearance of a new star which would, after a period of time, disappear. The light wave observed would have permeated spacetime for a distance of the observable emission duration * c for the period from it emission until its reception or detection, when its energy and momentum would be manifested as a number of quantisized photon particles.
Whether a radar gun emits one microwave photon/sec or 10**10/sec, each photon is an independent oscillating quanta of energy, in phase or out of phase with others in the radar beam. There is no continuity or correlation between them other than their being part of the transmitted beam front in space-time. However, the radar gun could be seen as calculating the perceived change in average energy between the trillions of photons transmitted in the beam-front at T1, and their average energy shift received as a returned beam front at T2. There would be no real loss of energy in this average difference calculation, and one could argue that if there was a net loss of photon energy to the Universe, it could be offset by the energy spent in accelerating or decelerating the radar gun's target, especially if the radar gun, its power supply, the target and its power supply was considered as a closed, local system.
Reply | Report Abuse | Link to thisskeptik2 - IMO, any radar beam energy loss is absorbed by the beam target - nothing to worry about there.
Reply | Report Abuse | Link to thisI am intent on describing all emitted EM energy as a wave form, until it is detected, manifesting as a stationary photon, or in the case of a heavier particle, a stationary, massive particle. I consider that even atomic nuclei manifest their energy as wave forms when 'jiggling' and as particles of spinning, stationary mass when not.
Re. your statement: "EM radiation travels as quanta of energy not as a continuous wave"; I agree that the wave is not continuous but I assert that energy traverses spacetime only as a cohesive wave form, potentially containing the energy of many stationary, potentially massive particles, and that stationary particles are manifested only upon detection.
IMO, massless photons traverse spacetime as continuously self-propagating wave forms. Unlike an energy wave in air, water or a saw, EM radiation also self-propagates in a vacuum either between or along material structures. an energy wave passing through a medium does so by energizing atoms, which then energize neighboring atoms producing a wave front. The wave form is produced in and of the medium material. Light energy disperses across spacetime: it is its own wave material.
Of course, you may be correct and I incorrect, but I think it cannot be argued that a detected wave can continue to be a wave, only whether a propagating photon is actually a wave...
By the way, I insist that material energy propagates as a wave and materializes as a stationary particle because I envision that matter's emission energy manifests intermittently either as propagation or as mass: it is the same energy either providing motion of configured to resist motion.
Reply | Report Abuse | Link to thisIMO, mass is not properly a characteristic property of particles: it is independent as is applied energy. No Higgs boson exists.
Dear SciAm,
Reply | Report Abuse | Link to thisI find the timing of your publication of Tamara Davis's "Is the Universe Leaking Energy?" in your July 2010 somewhat obscure. On the one hand, there is little in the article that could not have been written 40 years ago. On the other hand, the article reproduces many of the usual confusions that swirl around the issues of conservation and localization of energy in General Relativity. As it happens, it was realized recently ("Gauge-invariant localization of infinitely many gravitational energies from all possible auxiliary structures," _General Relativity and Gravitation_ 42:601-622 (2010)) that gravitational energy localization and conservation make perfectly good sense in terms of Noether's theorem, once one gives up the traditional but arbitrary quest for the One True Energy. Davis starts well in mentioning Noether's theorem, but goes astray in thinking that the space-time metric/gravitational metric needs a time translation symmetry in order to yield energy conservation. As Peter Bergmann noted clearly in 1958, there are uncountably infinitely many time translations in General Relativity, which lead to correspondingly many conserved energies. One needs only to accept this mathematics, rather than evaluate it by preconceived but arbitrary or irrelevant assumptions. The equivalence principle is true but irrelevant, while the assumption of One True Energy, which lies behind the wish for a tensor transformation law that gravitational energy-momentum pseudo-tensors do not have, is motivated primarily by lack of imagination and reluctance to listen to the mathematics. I pity the instructors whose students, on exposure to this article, conclude that either they cannot understand physics, or that physics does not make much sense. Various authors, taking too seriously this message of confusion, have concluded either that energy-nonconserving processes are permitted by General Relativity or that General Relativity is flawed. But gravitational energy really is conserved (in the sense of a partial divergence, so integration yields global conservation laws). Indeed the conservation laws are logically equivalent to Einstein's equations. The main surprise is that there are many distinct energies (and momenta). That outcome is clear if one holds loosely to preconceptions and listens carefully to the mathematics. The alternative is to have nothing intelligible to say to those who take seriously the claim of no conservation laws and derive erroneous conclusions.
Sincerely,
J. Brian Pitts, Ph.D., Ph.D.
First of all let me say I’m not a scientist and I have a couple of questions that must occur to just about all lay people who read about the Big Bang but are too embarrassed to ask.
Reply | Report Abuse | Link to thisThe first question is: why couldn’t the phenomena of red-shift be explained by postulating that photons loose momentum as they travel through space, perhaps leaving behind some minute particle of matter?
The second question is: at what scope does expansion of the universe take place? We know the atoms are not flying apart from each other also I think planet earth is still holding together. So what are exactly the conditions that hinder expansion and why were they not present while the Big Bang was going on?
Please answer only if you are actually qualified and know the answers.
I think we have to think of the possibility of photons slowing slightly as they pass through the "ether" of Einstein's original theory, which he abandoned. We KNOW they slow going through GLASS (it is how a lens works), so it is not impossible that photons slow down over space, and thus the red shift is expressed over distance that way.
Reply | Report Abuse | Link to thisWhere does the energy go? Into the dark energy & matter (ether) out there, perhaps, as it passes "through" it much like it does going through ordinary glass - but over a much more expansive time-frame.
I want to add, light waves slow down if moving through a medium, so they do not have to be expressed as particles, but can still exist as waves. Dark matter is a medium we were not aware of until recently, and light may be slowing down as it passes through it, just like light does when it passes through glass [or water] on Earth. (It's how the lens works.) I think that might have to be acknowledged soon.
Reply | Report Abuse | Link to thisthis is one of the topics i discuss in my recently published book : The Short Range Antigravitational Force and the Hierarchically Stratified Space-time Geometry in 12 Dimensions. the universe has a complex hierarchical structure of space-time geometry comprised of three strata each of which has its own values for the fundamental parameters and stratum specific variations in the nature and range of the fundamental forces. baryonic matter oscillates through all 3 strata ( comprised of 12 dimensions- 9 space and 3 time). dark matter oscillates through the lowest two substrata (and its 8 dimensional structure- 6 space and 2 time), and dark energy operates within the lowest substrata and its 4 dimensional structure. the continued expansion of the universe is fueled by the continuous inter-stratum conversion of maximum wavelength electromagnetic energy(and perhaps neutrinos) into dark energy. the book goes into more detail about these issues. christina knight
Reply | Report Abuse | Link to thisMatter moving away from us near the edge of the visable universe is doing so against the pull of gravity which would pull all the matter in the universe together if it could. The energy of that matter is, therefore, being raised with respect to us just like a weight being lifted against the Earth's gravity is. That is where the "lost" energy of the red-shifted photons is. It is simply being left behind with the matter that emitted them.
Reply | Report Abuse | Link to thisThe energy of a photon is hc/�. As � increases because of redshift, the photon's energy decreases. The question is whether this violates the principle of conservation of energy. On the other hand, expansion of space increases the gravitational potential of galaxies as they move farther apart. Dark energy was postulated to account for that increasing energy. Dark energy is presumed to preexist (perhaps in another universe, and leaks into our universe). So why didn't they assume that the increase in gravitational energy is balanced by the redshift of light energy?
Reply | Report Abuse | Link to thisI'm going to have to ask whether the redshift actually decreases the energy of the light, or whether that is just an apparent effect of changing coordinate systems. I'll get back to you on that after I've had time to think about it.
EDIT: It's all about the difference between the comoving coordinate system and a non-comoving coordinate system. Actually, I'm not sure what the correct name is for this non-comoving coordinate system, but I shall call it Euclidean coordinates. In Euclidean coordinates, the relative velocity due to expansion is real; in comoving coordinates it is only "apparent" velocity. In Euclidean coordinates, energy is conserved; the wavelength of a photon is constant, so its energy is constant. In comoving coordinates, energy is not conserved; the wavelength of a photon lengthens, so it loses energy. The term energy does not carry the same meaning in both systems.
In Euclidean coordinates, the rate of change of distance for a radial photon is �r/�t = c. In comoving coordinates, �r/�t = c(1+H�r). In comoving coordinates, radial speed is not the same as rate of change of distance.
When I say Euclidean coordinates, I'm referring to a coordinate system defined by hypothetical infinitely rigid massless tape measures whose centers are motionless at the origin, relative to comoving space. The tape measures do not bend or stretch as space expands, so objects which are comoving with the origin have real radial velocity. At small distances, v = H�r. (H� is the Hubble constant.) Special relativity does contract the radial dimension of comoving objects in Euclidean coordinates; time dilation and mass increase are also real. Consequently, at greater distances, the rate of expansion is Hc = H�/ �. This makes the math rather difficult for me; it involves hyperbolic trig functions.
Points on the tape are accelerating, relative to comoving space, at the rate, a = �H��. If a radial tape thru the origin were real, it would be subjected to a real tension; � = +(�a)�r; � being the mass per unit length. (Anybody care to calculate how long a carbon nanotube tape could be without snapping because of the expansion of space?)
Now that Ive established the difference between coordinate systems, lets look at how a radial photon behaves in each system. Suppose a photon is emitted from a Hydrogen atom at the origin of a Euclidean coordinate system; several billion years later, it is absorbed by another hydrogen atom which is comoving with the origin. (I cant give the exact number of years because I dont know how to do the math.) Lets say the wavelength of the photon in comoving coordinates is twice what it was when emitted. In Euclidean coordinates, the photons energy has not changed, but the mass of the absorbing hydrogen atom is twice its rest mass. In comoving coordinates, the energy of the photon is half as much, but the absorbing atoms mass is equal to the rest mass.
My first post, here, above. My Greek characters, etc., didn't work. I copied & pasted from my response at Yahoo!Answers. The special characters did work there. http://answers.yahoo.com/question/index;_ylt=Akti8HJJXO1WnzUejhLJxW3ty6IX;_ylv=3?qid=20100811084629AAWB8Fc&show=7#profile-info-94125d45439fc64e204f1084ebe7f709aa
Reply | Report Abuse | Link to thisMy first post, here, above. My Greek characters, etc., didn't work. I copied & pasted from my response at Yahoo!Answers. The special characters did work there. http://answers.yahoo.com/question/index;_ylt=Akti8HJJXO1WnzUejhLJxW3ty6IX;_ylv=3?qid=20100811084629AAWB8Fc&show=7#profile-info-94125d45439fc64e204f1084ebe7f709aa
Reply | Report Abuse | Link to thisPhractal Phil, Adam_Smith - To better understand the basis for the proposed requirement for some dark energy accelerating the expansion of the universe, I strongly suggest you refer to “Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant”, 1998, Riess, et al, archived at:
Reply | Report Abuse | Link to thishttp://arxiv.org/abs/astro-ph/9805201v1
In summary, this is the initial report introducing the evidence for an accelerating universe. In it, observations of more distant galaxies, unlike nearer galaxies observed, seemed to indicate that galaxies nearer the spatial periphery of the observed universe are receding away from their observers (us) more rapidly than galaxies that are nearer to their observers.
More specifically, the relationship between independently estimated distance based on supernovae luminosity and the redshift of galactic light was found, for distant galaxies only, to be inconsistent with standard cosmological models, exceeding their predictions.
It was concluded from this data that the expansion of the universe began accelerating about 5 billion years ago.
However, those more ancient light emissions indicating greater rates of expansion reflect the expansion rate of the earlier universe. Those precise observations only confirm the expected deceleration of the universe. It's kinda like looking through the wrong end of the telescope...
In any event, whether expansion is now accelerating or not, in any expanding universe there was an initial application of energy that produced its initial expansion (with or without an inflationary period). That initial expansion energy obviously overcame the then stronger effects of gravitation (in a smaller, denser universe) and has continued to do so ever since, without the help of any dark energy that is proposed to have become effective about 5Gya.
Reply | Report Abuse | Link to thisThis initial expansion energy must be considered in any accounting of universal energy. It's not just redshift vs. gravity vs. dark energy...
Only 118 responces to this simple question. Is entergy conserved? We might want to consider that what we call laws of entergy in a local area may not apply to areas such as distant areas. Yes i thing we all can say that on earth and in the milky way. Most of the known laws we are aware of might very well be the norm. But why would we consider that the whole universe is reflective of our own tiny part. We here light. And think if light rays and waves. Yet what is light. Is it raditaion. Or is it light. Or is it both? Actually the story is just now being wrote on what light is. Sometimes even wise people become blind to the simple overt observations.
Reply | Report Abuse | Link to thisHow can there be conservation of entergy. It is a easy study really. We are in a open system. Not a closed system. And there is were the problem is. As light approaches th edges of the univers, were the waves die. Were the wave length becomes zero. What then. Well the entergy was lost in flight and also in death of the light wave. Thus it is expended. But lets think about all the red shifts and the blue shifts and the journey. First off we humans think of light as being something we can see like a brick wall. There are forms of light. And types of bodies that affect light. And there is the unseen universe. Duel froms of entergy conservation laws. What you see is not all there is there. I point you to the Bible for a second. A great reference book. For everything under the sun and time to be born and a time to die. Lets apply that to light. Light is born in a star. Due to a reaction with in the star. Then after birth it is send into the universe. "a example only" So if light was born it also dies. Absorbed amounts to death. But not all light is absorbed. Some just runs out of steam. Death is death.
But is there conservation in the from we think of. I think it is somewhat but not 100 percent we have a entergy leak in my thinking. And with out that leak the universe would not be able to function. Consider is light was restrictive and had no decay. The universe as we know it could not move. It would become ridiged and fixed. It is the ability to move that allows the system to work. When you put you hand in a bucked of ice it becomes hard to move your hand. The same thing applies to the universe. There is cause and affect. Light is more important then many may think. And light is folded and woven, but i will let you folks find out why that is important and how it applies.
A POSSIBLE EXPLANATION FOR LOSS OF ENERGY IN THE UNIVERSE:
Reply | Report Abuse | Link to thisPhotons are being observed leaving the universe. Theoretically, this is not possible. The most likely explanation is that they are "feeding" an alternate universe or universes. Since photons are exiting our universe, this alternate universe is most likely sub-atomic in nature(with galaxies, solar systems, planetary bodies, and possibly life) relative to us and existing in our own universe, perhaps on Earth (a micro-chip, etc) and may be entering this alternate universe in the form of tachyons (superluminal particles), hence, traveling backwards in time, re-entering normal space-time relative to the alternate universe in which they enter. As such, our own universe may in fact be shrinking as this universe expands. Relative to us, we would appear to be expanding. Eventually, a form of "Archimede's Principle" (or conservation of momentum and energy) may occur, and a 50/50 balance will occur (making the universes parallel), or our universe will collapse into the other, which technically cannot occur as the smaller universe exists in ours, therefore time will halt momentarily in both universes, a burst of energy occurs, and the process reverses, creating a type of continuum.
Robert T. Permar
Dunno, but I for one am impressed at the number of apparent "laymen" who even pay attention to stuff like this, much less try to solve these formidable sorts of problems. And historically, a lot of discoveries have originated from the work of "amateurs" working outside the "mainstream". But if nuthin' else, isn't it great to know that some folks are actually using the internet (and their brains) for something better besides downloading mp3's, watching "viral videos" of talking dogs, or even trollish complaints!
Reply | Report Abuse | Link to this