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Why the search for a unified theory may turn out to be a pipe dream

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Einstein's last years were marked by a futile search for a grand unified theory (Image: Wikipedia Commons).

Unification is an ancient goal in physics. From the time that 19th century physicists like Maxwell and Clausius attempted to unite disparate physical phenomena, the search for a grand unified theory that would conjoin every known force and physical law has always been an implicit or explicit dream of physicists. The search for unification is in one sense a search for harmony, a desire to view the whole universe through the lens of a single elegant law or equation that would explain everything.

Most attempts at unification have been remarkably successful. First the pioneers of thermodynamics brought together mechanics and heat and then Faraday and Maxwell achieved the spectacular goal of weaving electricity, magnetism and optics together into a seamless tapestry. Even Einstein’s famous equation can be seen as a kind of unification, serving to underscore how fundamental quantities like matter and energy are just two sides of the same coin.

Unification thinking pervaded the twentieth century, from establishing wave-particle duality to creating a common framework for understanding special relativity and quantum mechanics. Pioneers of particle physics like Feynman, Weinberg and t’ Hooft brought us tantalizingly close to the ultimate goal of a “final” theory. But only tantalizingly so; famously, gravity remained intractable and its union with quantum theory has remained perhaps the greatest unsolved problem in physics for the last fifty years. Many of the world’s best minds from Einstein to Edward Witten have tried to solve the problem with scant success. String theory claims that it can achieve the task, but it is no closer than other theories to making hard, testable predictions to this effect.

From an experimental perspective one of the best bets for probing a quantum theory of gravity is to look for gravitons, particles that are thought to mediate the gravitational force. The fundamental problem with detecting gravitons is the extremely weak nature of the gravitational force. To address this problem researchers have designed exceedingly sensitive equipment that should in principle be able to detect even discrete gravitons. One of the triumphs of this effort is LIGO, the Laser Interferometer Gravitational Wave Observatory, which is using extremely sensitive interferometers to detect the minuscule shifts in space-time caused by the passage of a gravitational wave. LIGO is a marvel of both physics and engineering and has been really designed to detect gravitational waves which are a prediction of classical general relativity. A typical experiment will study the interference of a highly focused laser beam bouncing off two mirrored cavities at a given distance, waiting for a gravitational wave from a defined source to pass between them. Then, as Wikipedia puts it:

When a gravitational wave passes through the interferometer, the space-time in the local area is altered. Depending on the source of the wave and its polarization, this results in an effective change in length of one or both of the cavities. The effective length change between the beams will cause the light currently in the cavity to become very slightly out of phase with the incoming light. The cavity will therefore periodically get very slightly out of resonance and the beams which are tuned to destructively interfere at the detector, will have a very slight periodically varying detuning. This results in a measurable signal. Note that the effective length change and the resulting phase change are a subtle tidal effect that must be carefully computed because the light waves are affected by the gravitational wave just as much as the beams themselves.

Note the last statement that talks about the subtlety of the effect. But the subtlety may be even more amplified when it comes to detecting gravitons themselves. How subtle would the effect of discrete gravitons be? In a chapter in John Brockman’s recent book, Freeman Dyson from the Institute for Advanced Study in Princeton tries to quantify the subtlety (the chapter is reprinted as an essay in the IAS newsletter). In the process he also tells us that the effort to unify gravity and quantum mechanics might be doomed after all. The key effect here is the displacement of the two mirrors induced by the passage of a gravitational wave which causes a change in the interference of the laser beams, leading to a signal. Dyson’s calculations demonstrate that this change might be so small that it would be swamped by “background” quantum fluctuations in space-time. Well then, you might say, we will just make the mirrors heavy enough so that they won’t be perturbed by the quantum fluctuations. Dyson tells us just how heavy they will have to be:

“Because of ambient and instrumental noise, the actual LIGO detectors can only detect waves far stronger than a single graviton. But even in a totally quiet universe, I can answer the question, whether an ideal LIGO detector could detect a single graviton. The answer is no. In a quiet universe, the limit to the accuracy of measurement of distance is set by the quantum uncertainties in the positions of the mirrors. To make the quantum uncertainties small, the mirrors must be heavy. A simple calculation, based on the known laws of gravitation and quantum mechanics, leads to a striking result. To detect a single graviton with a LIGO apparatus, the mirrors must be exactly so heavy that they will attract each other with irresistible force and collapse into a black hole. In other words, nature herself forbids us to observe a single graviton with this kind of apparatus.”

When I met Dyson last year he told me that he had tried hard to find a flaw in the calculation, to no success. If true this limitation goes much beyond detecting discrete gravitons. It could mean that the world of gravity and the world of subatomic particles will forever stay separate from each other, being disallowed from sampling each other’s domains by a fundamental physical barrier. As Dyson puts it:

“If this hypothesis were true, it would imply that theories of quantum gravity are untestable and scientifically meaningless. The classical universe and the quantum universe could then live together in peaceful coexistence. No incompatibility between the two pictures could ever be demonstrated. Both pictures of the universe could be true, and the search for a unified theory could turn out to be an illusion.”

Should we feel chagrined if this indeed turns out to be the case? I don’t think so. The lack of a theory of a quantum gravity may mean an end to efforts at unification, but it would indicate that the universe is much more diverse than we think. Unity and diversity contribute equally to the beauty of the cosmos. Darwin’s theory is a perfect illustration of this fact; while providing a common mechanism for the evolution of species, it is also a testament to the astonishing variety of living creatures on our planet. If a unified theory of nature does turn out to be a pipe dream, we should celebrate the fact that whatever creating force was responsible for the evolution of the universe chose to make it more interesting than we imagined. The lack of a unifying theory would be a perfect embodiment of Haldane’s quote that “the universe is not only queerer than we suppose but it’s queerer than we can suppose”. Our failure at finding a unified theory would only mean our success in discovering that the universe is an inexhaustible source of riches. For this we should be grateful.

Ashutosh Jogalekar About the Author: Ashutosh (Ash) Jogalekar is a chemist interested in the history and philosophy of science. He considers science to be a seamless and all-encompassing part of the human experience. Follow on Twitter @curiouswavefn.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. barth 2:08 pm 05/3/2013

    Ash, your post was fascinating, and certainly presented a viewpoint I haven’t seen elsewhere, but it contained one omission that I fervently hope you can remedy. You say, “When I met Dyson last year he told me that he had tried hard to find a flaw in the calculation, to no success.” But you also say, earlier in the post, “To circumvent this problem researchers have designed exceedingly sensitive equipment that should in principle be able to detect even a single graviton. One of the triumphs of this effort is LIGO, the Laser Interferometer Gravitational Wave Observatory, which is using extremely sensitive interferometers to detect the minuscule shifts in space-time caused by the passage of a gravitational wave.”

    Obviously, scientists would not undertake a costly and time-consuming experiment if success were theoretically impossible. So their own calculations must be entirely different from Dyson’s. Since you apparently have ready access to authorities in the field, I think–for your readers’ sake–you must get a detailed response to Dyson’s analysis from scientists connected with, or at least very knowledgeable about, LIGO. Can they spot exactly where Dyson goes wrong? Or do Dyson’s calculations come as a revelation to them, and they suddenly realize the futility of LIGO?

    And may I close on a slightly personal note?: I’m dying to know the answer to my questions!!!

    Link to this
  2. 2. jtdwyer 4:24 pm 05/3/2013

    As I understand, gravitons are proposed to mediate an exchange of an unidentified quantum gravitational force between particles – based solely on the presumption that gravitation must be a material force or quantum interaction like electromagnetism and the strong and weak nuclear forces.

    However, general relativity does not describe gravitation as an exchange between particles or even objects of mass. It successfully describes gravitation as an interaction between objects of mass and an unidentified geometric property of spacetime, using a system of coordinates representing its dimensions.

    IMO, this distinction, along with the apparent local ‘weakness’ of gravitation, seem to indicate that the effects of gravitation are fundamentally distinct from the material force interactions. Certainly, bound mass-energy is a crucial component, but there seems to be a missing component directly associated with the dimensions of spacetime. I suspect this missing component is vacuum energy density.

    Consider that the accretion of matter and potential mass-energy is a two-way street: it also produces the extraction or evacuation of mass-energy from the vacuum – perhaps producing the dimensional distortion of spacetime…

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  3. 3. M Tucker 4:57 pm 05/3/2013

    It seems that we are talking about two distinct things: Gravitational waves and gravitons. The idea of gravitational waves come form general relativity while the idea of gravitons comes from quantum field theory. It might be that we discover that gravitational waves do exist while the proof of the existence of the graviton continues to elude us. The existence of one does not seem to depend on the other. It might be that gravity does not need a force carrying particle like the graviton. Gravity might simply be the effect observed when a mass warps space-time.

    However, I think physicists will continue to look for unification because of black holes.

    Link to this
  4. 4. gesimsek 5:20 pm 05/3/2013

    Looks like back holes exist because of the collapse of distinction between mass and energy under their own particular conditions.

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  5. 5. M Tucker 5:32 pm 05/3/2013


    With black holes I mean that general relativity predicted black holes and they were eventually found. The radiation escaping from black holes was finally explained by quantum mechanics. Also the problem of whether information is lost when a particle falls into a black hole was resolved by quantum theory. This intimate connection between general relativity and quantum theory is one reason modern physicists still pursue a unification theory.

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  6. 6. jtdwyer 6:47 pm 05/3/2013

    M Tucker,
    As I understand, Hawking’s famous black hole radiation hypothesis has never been definitively confirmed, either through experiments or observations. Please see

    Link to this
  7. 7. jtdwyer 7:00 pm 05/3/2013

    M Tucker,
    I certainly agree that there is no substance – only speculation regarding the existence of gravitons, including the hope that gravity waves, if they can ever be detected, will propagate at less than the speed of light. That then might could be explained if it were gravitons that were waving, and that they had some mass.

    I agree that what ever property of spacetime that is curved is what is waving in gravity waves, as predicted by general relativity. There’s little reason to even speculate that it might be those undetectable little gravitons, even if they did have mass. Please see
    “In physics, the graviton is a hypothetical elementary particle that mediates the force of gravitation in the framework of quantum field theory. If it exists, the graviton is expected to be massless (because the gravitational force appears to have unlimited range) and must be a spin-2 boson.”

    Link to this
  8. 8. jtdwyer 7:06 pm 05/3/2013

    I forgot – re. those waving gravitons, please see
    “However, experiments to detect gravitational waves, which may be viewed as coherent states of many gravitons, are underway (e.g., LIGO and VIRGO). Although these experiments cannot detect individual gravitons, they might provide information about certain properties of the graviton. For example, if gravitational waves were observed to propagate slower than c (the speed of light in a vacuum), that would imply that the graviton has mass.”

    Link to this
  9. 9. curiouswavefunction 7:43 pm 05/3/2013

    Yes, MTucker and jtdwyer, thanks for clarifying. I should have been clearer in the post; gravitational waves which are a prediction of *classical* general relativity are certainly (indirectly) detectable. Detecting individual gravitons in the manner of the double slit experiment in quantum theory is a different kettle of fish. Barth, good question; It’s something I too am interested in knowing, and I am in the process of getting in touch with a few colleagues who might know the answer.

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  10. 10. rloldershaw 11:48 pm 05/3/2013

    The Universe is highly unified. It is our incommensurable models that look like a quilt produced by a monkey.

    If we want a better understanding of nature then we will have to admit that some of our cherished assumptions (like strict reductionism, reversibility, absolute scaling for gravitation, etc.) must be wrong and begin to consider new ideas based on new fundamental principles.

    Here is one new idea that is highly unified, can make definitive predictions, and has had several predictions vindicated already.

    The odd thing is that failed theories like string theory and supersymmetry still get all the attention, while an elegantly unified new paradigm like Discrete Scale Relativity is almost totally ignored for 35 years.

    Do we want a better and more unified understanding of nature, or do we only want to ride our familiar hobby horses?

    Robert L. Oldershaw
    Fractal Cosmology

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  11. 11. Kantian 11:55 pm 05/3/2013

    Maxwell and Clausius were 19th century, not 18th century physicists.

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  12. 12. Bee 4:31 am 05/4/2013

    This article pains me considerably because I spend my time giving seminars explaining why Dyson’s pessimism is misleading. To find evidence for quantum gravity one doesn’t need to detect single gravitons. The phenomenology of quantum gravity is a thriving research area, thank you very much. One also doesn’t need to detect photons to find evidence for the quantization of electrodynamics. That atoms are stable is ample evidence, and it’s all around us. For basically the same reason, evidence for quantum gravity does not necessitate exciting or detecting quantum fluctuations of space-time, it is sufficient to detect their consequences, which can be at low energies.

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  13. 13. jtdwyer 6:18 am 05/4/2013

    I’d be very interested to know what consequences provide evidence for the existence of quantum gravitational effects, aside from you declarations. Can you please provide some references or supporting material?

    Again, to be consistent with quantum field theory wouldn’t a very large number of gravitons be required to transfer some gravitational force from one particle to another in order to mediate a gravitational attraction effect between massive objects?

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  14. 14. Chryses 8:04 am 05/4/2013

    Assuming for the moment that Prof. Dyson’s argument is verified, physicists, first theoretical, and then experiment, could focus their energies on a “Two Field” theory rather than the historical “Unified Field” theory. Were that effort to prove more fruitful than the prior ideal, it would be a change in Physics akin to the “two clouds” of Lord Kelvin’s 1900 speech to the British Association for the Advancement of Science.

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  15. 15. abolitionist 8:06 am 05/4/2013

    It is pleasing to visit a redoubt of thoughtful commentary and criticism here at the SciAm blogs.

    Link to this
  16. 16. syzygyygyzys 10:55 am 05/4/2013

    It is most likely that I don’t have enough understanding to ask a meaningful question on this subject. So please accept my apologies for intruding. But maybe someone here can improve my understanding?

    Doesn’t describing something as a “wave” imply that the wave exists in some medium? I recognize that not everything can be intuitive, but if someone can explain this to me in a non mathematical form, I would be grateful.

    For example if light is a wave that can be red shifted, is space actually “nothing”? Same question for gravity waves. Again, if you view my question as coming from insufficient education to understand the answer, I’m sorry to intrude on the conversation. It’s just something I have wondered about.

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  17. 17. Thony C. 11:14 am 05/4/2013

    “From the time that 18th century physicists like Maxwell and Clausius…”

    Sorry to be a pedant (well actually I’m not sorry!) but James Clerk Maxwell FRS FRSE (13 June 1831 – 5 November 1879) and Rudolf Julius Emanuel Clausius (born Rudolf Gottlieb; 2 January 1822 – 24 August 1888) are both as one can clearly see from their birth and death dates 19th century!

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  18. 18. Chryses 12:03 pm 05/4/2013


    “Doesn’t describing something as a “wave” imply that the wave exists in some medium? …”

    Yes, it does. That medium was in classical, determinant, Newtonian physics assumed to exist, and was labeled the “ether.” This medium was inferred to be the stationary frame of reference through which you, I, the Earth, and all the Cosmos moved. There were strong arguments why it should exist, for example Maxwell’s equations represent light as an electromagnetic wave, and it would need something to support its propagation. The ether had however, once you think about it some unusual properties. It had to be fluid enough to enable use to move through it without noticing its presence, and at the same time solid enough to support the propagation of light.

    As the Earth was assumed to be travelling through the ether, and at the same time is orbiting the sun, the Earth “had” to be travelling in opposite directions relative to the stationary ether every six months. So, in a manner similar to measuring the difference in the speed of a water wave when it is travelling with the flow of the water through which it moves, and comparing that speed to the speed of the same wave travelling in the opposite direction (drop a stone into a smoothly flowing stream), the physicists Michelson and Morley attempted to measure this delta for light travelling through the ether. This experiment produced the most important null result ever recorded and reproduced.

    Albert Einstein’s rethinking of the facts caused him to propose that there was, in fact, no ether. Yes, that was, and remains, unintuitive. But that theory fit the facts – the actual measurements, not what the measurements should have been – what they were then and remain today.

    One way to think about this is to think of the “wave” of light to be composed of many, many particles that may be described in their aggregate as a wave as they/it move(s) through space, but actually interacts with matter individually as “particles”. This “duality” is not unprecedented in physics, as thermodynamics uses aggregate mathematical descriptions to very accurately describe the behavior of the multitude of independent molecules that make up a gas.

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  19. 19. curiouswavefunction 2:05 pm 05/4/2013

    Fixed the anachronism, thanks.

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  20. 20. rloldershaw 3:21 pm 05/4/2013


    Briefly, Einstein showed that the classical stationary aether was a dubious conception, but there are other forms of aether that do not conflict with special or general relativity, such as a plasma of nearly infinitesimally small charged particles moving randomly and with velocities approaching c.

    Discrete Scale Relativity/Fractal Cosmology

    Link to this
  21. 21. jtdwyer 3:40 pm 05/4/2013

    syzygyygyzys, Chryses,
    “Doesn’t describing something as a “wave” imply that the wave exists in some medium? …”

    It may seem so to some, but no ethereal medium is necessary or even possible – massless quantum particles ‘perpetually’ self propagate through a vacuum at the characteristic velocity c by oscillating in relation to its direction of linear propagation. A quantum wave packet has a specific length, dispersed in spacetime, depending on its wave properties. Please see
    “On Coherence Lengths of Wave Packets,”
    “Quantum wave-packet size effects on neutron time-of-flight spectroscopy,”

    In fact, when light propagates (or more properly, is transmitted) through a medium, be it a cloud of hydrogen gas, the atmosphere, water or glass, its effective propagation speed is slowed to some extent. This is not because the propagation speed of light between atoms varies, but because the photons’ energy is absorbed by electrons then, depending on the material, is reemitted a short time later.

    In contrast, EM neutral neutrinos with almost no mass can propagate through the Earth, for example, at nearly the speed of light because they almost never interact with its atoms. They are propagating in the vacuum in between the atoms that comprise the Earth’s interior. I think this precludes any possibility that any medium is involved in quantum energy wave propagation through a vacuum.

    That fundamental particles self-propagate as an energy wave is wholly distinct from a compressive energy wave propagating through a material medium, such as the Earth, the atmosphere, water or even glass. There is no self-propagating fundamental particle involved in the propagation of a sound wave – as I understand it’s a flow of (externally applied) kinetic energy compressing/decompressing the density of a material media. Please see

    Link to this
  22. 22. Chryses 4:38 pm 05/4/2013


    Granted, and I may be mistaken, but I think syzygyygyzys was referring @16 to the medium which 19th Century physicists thought was needed to facilitate the passage of Maxwell’s electromagnetic radiation, and that was the ether I attempted to describe.

    I’ve read your commentary here before, and you’re more familiar with the particulars than am I: were not these “alternate ethers” proposed following, and in response to Special (1905), and then General Relativity (1916)?

    Link to this
  23. 23. rloldershaw 5:24 pm 05/4/2013


    Yes these alternative aethers were periodically proposed and used, for example, as an alternative assumption in modeling quantum mechanics phenomena.

    However, even though Einstein stated that it was only the old classical stationary aether that was falsified, it became dogma that aether was anathema and all aethers were tarred with the same brush. That has changed a bit in recent years and the idea of an alternative aether has appeared more frequently in the physics literature lately.

    Here is a way to visualize what I referred to before. Cosmic rays constitute a low-density relativistic plasma of charged (and uncharged) particles that pervades the Galaxy and probably the entire observable universe.

    Now imagine a self-similar plasma of relativistic particles that are smaller and less massive than CRs by factors of 10^17 and 10^56, respectively. This would constitute a subquantum aether that is not ruled out by existing observations. It would be very hard to observe the individual particles, although there is some empirical evidence for this aether and it is mentioned in the link I put in post #10. At any rate, their collective effects might well play an important role in quantum phenomena and other enigmas, unsolved problems,…

    In my opinion, gravitons are pure fiction.

    Robert L. Oldershaw
    Discrete Scale Relativity/Fractal Cosmology

    Link to this
  24. 24. bwiley1 6:55 pm 05/4/2013

    I like this article because it poses a simple thought worth considering – what if there really is no unification? We obviously don’t know the answer, but it is a fun question worthy of some brain cycles.

    When I think of the word “gravity”, I try to replace it with the words “curvature” or “acceleration”. The statement that gravity may not have a quantum foundation becomes: Curvature may not have a quantum foundation. Acceleration may not have a quantum foundation. Hmmm.

    As to gravity waves, we understand the various fundamental particles all possess particle-wave duality and when it comes to “wave” we aren’t talking about some physical wavy or waving manifestation of something. Those waves are probability waves, representing higher (peak) and lower (trough) probabilities of finding the associated particle in a given quantum state.

    So back to gravitons and their associated gravity waves. Aren’t gravity waves probability waves associated with a graviton’s quantum state? How would the quantum uncertainty associated therewith ever manifest itself as a perfectly smooth curvature of physical spacetime? By definition, probability and uncertainty don’t allow consistent, perfect, smooth curvature. Or is that the conundrum we are trying to unify?

    Fun stuff.

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  25. 25. m 11:04 pm 05/4/2013

    Ill comment on the aether.

    Assuming the aether is a transmission medium so negating the need to gravitons are we propose them then the medium must be able to be interacted with matter/waves.

    Using Tesla principle if enough waves going through the aether intersect then at that interseection point you would get further interactions with matter.

    These further interactions with matter while slightly appearing chaotic would be able to be detected, something would move slightly.

    Now due to the fact everything is emitting gravitational waves as proposed, then there are intersection points everywhere and thus slight variations could conceivably be detected close to the center of say our galaxy, as we dont know where the center of the universe is I bet.

    NOw while most intersection points perhaps do not muster enough energy to move matter, its also possible these virtual particles are created from these energy convergences.

    All worth a good conversation.

    Link to this
  26. 26. m 11:06 pm 05/4/2013

    * for gravitons as we propose them

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  27. 27. syzygyygyzys 11:14 pm 05/4/2013

    Thanks everyone.

    Link to this
  28. 28. aloysi 7:09 am 05/5/2013

    To resolve all the confusions occurring in current physics, we have to realize the real meaning of energy or what is energy or how to work it. Because the universe is made up of energy and mass and all we know that energy can neither create or destroyed, it can be convert in one to another form. So the fundamentals of our universe is the same constant amount of energy and mass which will never less or more. So all the phenomenon’s occurring in our universe is through the conversion or transformations of this constant amount of energy. Now we have to know that how the energy is transforming in one to another form. Once we realize it clearly we can explain our surroundings too.
    For that we have to know what is energy or what we are calling energy. Simply we can say that which can do a work is energy. We can say the universe is always under the influence of energy and work. The universe is expanding ( in a uniform motion ) through the work done by the big bang. Now we are having the very famous equation E = mc2, where E is energy , m is mass and c is velocity of light. By this equation we will get the amount of energy stored in a matter or a particle. According to this equation we can say a mass can accommodate a constant amount of energy at normal stage. Here the mass is the tool to measure the amount of energy stored in a particle.
    Now we will try to know that what is energy. For that we have to know that what is happening in a matter or a particle or anything which we can observe in our surroundings. To explain this we will tell you some examples which we can see in our daily life. Now I am considering me as a source of energy. Now I want to through a stone little far away. So I took the stone and threw it away. We will see what is happening now. To take it or lift it I am using my energy on that object or applying a force on it. Once I lift that object the force applied by me do the work and the energy which I use to apply the force is converted into potential energy to that object. So the quantum energy which I use is emitting as in the form of force and by the work done it is converted as potential energy. When I threw it my force ( because I am a source of energy ), work done will convert the applied force as kinetic energy and the force will carry the object a force is need to do work and work will convert it into another form. Here we can say that work is the mediator to convert energy to another form and energy is releasing as in the form of force as quanta. Once a mass release force it will lose the same amount of force and energy. But the mass remains as same. Now we can say that energy as the force stored by the mass. And a moving object will increase only gravity due to the applied force but not increase mass because gravity is proportional to the stored force. Force between two objects we may say G*F1+F2 divided by the distance.
    Now we will see how is creating electrical energy in a hydroelectric project. The force which is having the water fall will do the work on the turbine will create the mechanical energy and he same mechanical energy release the force to do work on a magnetic force created by the magnetic field. The work done by the external mechanical force one the magnetic field will create or convert the mechanical force to electrical force and stored as electrical energy. Once electrical energy act on other mechanism the work done will convert it into another form as the result of the applied force by the electrical energy.
    Now we can say that an energy is emitting a force in the form of quanta to do the work and according to the force emitting of force the same amount of force will lose the source and the energy on the source will be seen to less the same amount of energy. The force release by an energy can carry a mass (ENERGY).
    As I said before a mass can accommodate a constant amount of energy on it at normal condition, but it varies according to the surroundings where the object is. That means the energy of an object will depend upon the absorption or emitting of force of the same object in accordance with its physical surroundings. For example if we heat an object the force experience around will increase and the mass will absorb the quanta of force from its surroundings and increase the energy. Once we remove the heated energy the body will emit the absorbed force by the heat in the form of the work done on these two stage will be equal. So energy is storing in a mass as quanta in the form of force. So the energy stored in an object will be (mc2)-m. energy of a mass is proportional to the force or E=F stored on it.
    Now we will see what is happening when an object falls from high to the surface of earth. Work done by these two objects stored force will create the gravity and attract each other. Once these two bodies attract each other and move closer through gravity as a result of the work done by the stored force and collide in the surface. At this stage the work done by these two bodies will be almost maximum and the absorption and emition of the force are will tend the body to move more closer to the center of the body. At this stage through the gravity a winding energy will be created between these two objects. The force between these two bodies will be (F1+F2) divided by the distance. Here F of the body will be (mc2)-m. so the work done by these force (gravity) will create the winding force between them. The same winding force act as strong and weak interactions of the particles. So the force stored in a mass is creating the weak and strong interactions. And the surroundings where the force store on that particle will determine the properties of the particle or the matter.
    Now we will observe the universe. According to me the universe is not expanding but it is on a uniform motion. There must be two independent empty space in the universe. One is in the outer end and another will be at the inner end. The outer end is uniformly occupying an empty space and the inner end will create an empty space after that due to the uniform motion of the universe. Each particles in the universe at the same uniform motion. The area occupied by the outer end of the universe will be equal to the empty area created by the inner end due to the work done by the universe. Otherwise the dark energy cannot accelerate the occupation of the universe on an empty space. If the universe is expanding from the center, the distance from the center will increase and the force is not enough to accelerate. So the universe must be at a uniform motion. So everything which is happening in the universe is concentrated and in a uniform method that we can sat like this way .
    E=mc2 or E = m* stored force
    Energy—–emit or absorb—–force—-to do — work—-transform or store —–as energy.

    Link to this
  29. 29. mudphud 9:21 am 05/5/2013

    Perhaps I misunderstood something, but although LIGO was thought in theory to be able to detect gravitons, it’s main purpose is to detect gravity waves. The article concludes we will never be able to detect gravitons, but the quotes from Dr. Dyson merely say that the method used by LIGO will never be sensitive enough to detect gravitons, or rule out their existence. That doesn’t mean they can’t be detected, just that if they can be, another method will be needed. Hopefully at some point someone will propose another theory that includes a prediction of graviton behavior that can be tested.

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  30. 30. david123 10:53 am 05/5/2013

    Ash, Barth asked a good question and a couple of people — mudphud most recently — provided a reasonable response. But I would really like to get your take on Barth’s question in comment 1. Thanks.

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  31. 31. david123 10:55 am 05/5/2013

    curiouswavefunction, I will be interested in reading what your colleagues say about this.

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  32. 32. rloldershaw 11:05 am 05/5/2013

    According to Discrete Scale Relativity gravitation works exactly as General Relativity proposes on all fundamental cosmological Scales (…, Subquantum, Atomic, Stellar, Galactic, Metagalactic,…) of nature’s infinite self-similar hierarchy.

    We don’t see any “gravitons” whizzing between the Sun and our planetary system, do we?

    Discrete Scale Relativity claims that the concept of “gravitons” is a product of our mistaken belief in strict reductionism and our lack of understanding of nature’s discrete fractal (self-similar) scaling.

    These mistaken assumptions also lead to the vacuum energy density crisis, the failure to identify the galactic dark matter, the incommensurability of GR and QM, and many other problems.

    Robert L. Oldershaw
    Discrete Scale Relativity/Fractal Cosmology

    Link to this
  33. 33. bigbopper 11:38 am 05/5/2013


    Einstein’s 1905 paper on the photoelectric effect solved the conundrum of how light could travel through space empty of any medium: he introduced the concept of light as a particle (photon) with wave-like properties (energy equals Planck’s constant times frequency). Particles don’t need a medium to travel in. This concept was not widely accepted until 1923 when Compton showed that photons have momentum as given by the de Broglie equation (momentum equals Planck’s constant divided by wavelength).

    This is the fundamental wave/particle duality.

    Link to this
  34. 34. bigbopper 11:41 am 05/5/2013

    To jtdwyer:

    Gravity can be quantized: see Loop Quantum Gravity. This leads to quantization of space itself (minimum lengths, areas, and volumes given by the Planck length, area, and volume). What is lacking is experimental validation that this theoretical construct actually describes physical reality. A work in progress with no guarantee of eventual success.

    Link to this
  35. 35. N a g n o s t i c 12:41 pm 05/5/2013

    I occaznally unify everythin with a misture of vodka, pineapple and sativa

    Link to this
  36. 36. jocelynread 2:48 pm 05/5/2013

    Single graviton detection is not part the LIGO program; the LIGO detectors would not expect to be able to measure a solitary graviton even in an ideal scenario. However, LIGO can *directly* detect gravitational waves produced by an astrophysical event, which would be made up of gazillions of gravitons acting on the detector; this is independent of the details of a quantum gravity theory underlying General Relativity.

    Link to this
  37. 37. rloldershaw 4:47 pm 05/5/2013

    But from the scientific point of view, it is important to bear in mind that not a single gravitational wave and certainly not a single “graviton” has ever been observed. There has been a huge effort to do so, but so far no luck at all. Sort of reminds one of “WIMPs”, magnetic monopoles, axions, extra dimensions, …

    We should not treat these hypothetical entities as real physical objects until we have some solid observational evidence that they are more than theoretical pipe dreams.

    Robert L. Oldershaw
    Discrete Scale Relativity/Fractal Cosmology

    Link to this
  38. 38. barth 5:09 pm 05/5/2013

    Little did I suspect that I would have to turn sleuth in pursuit of an answer to the questions I posed in Comment #1!!!!

    There really are two issues raised by Ash’s post:

    First, two contradictory assertions are referenced in the post regarding the ability of scientists to detect single gravitons, one by Freeman Dyson, who seems to deny the possibility, even theoretically, and the other by—well, it’s not clear what Ash’s source is for his own statement, “To address this problem researchers have designed exceedingly sensitive equipment that should in principle be able to detect even discrete gravitons” Are there “researchers” actually claiming that their equipment, in principle, should be able to detect single gravitons?

    So what have I learned about all this since reading Ash’s provocative post? First of all, Ash links to the newsletter for IAS (Institute for Advanced Studies in Princeton) which contains a piece by Dr. Dyson on this subject. A careful reading of this brief article reveals that Ash didn’t mention an important qualifier that Dr. Dyson included. After Dr. Dyson explained his basis for ruling out, theoretically, the detection of a single graviton by even an idealized LIGO-type apparatus, Dyson then uttered some crucial words that Ash omitted: “I propose as a hypothesis, based on this single thought-experiment, that single gravitons may be unobservable by any conceivable aapparatus.” So it turns out that Dr. Dyson was more cautious than Ash suggested, since Dr. Dyson himself recognized that his calculations regarding an idealized LIGO’s inability to detect a single graviton, EVEN IF CORRECT, would not provide a firm basis for his philosophical conjectures about the futility of pursuing a unified theory. There’s a very important intermediate step that must be taken first– proving that single gravitons are unobservable by ANY CONCEIVABLE APPARATUS.

    So, next, I did a little research on whether THAT question has been addressed. And, happily, it turns out that a pair of physicists, provoked by Dr. Dyson’s assertions, investigated this very issue!! In a paper entitled, “Can Gravitons Be Detected?” Tony Rothman of Princeton and Stephen Boughn of Haverford College did an exhaustive analysis. And after 17 pages densely filled with equations whose complexity might have given shivers to Feynman, we have this conclusion: “In sum, we can say that to detect a single graviton was a priori going to be a difficult proposition, but it was not obvious that it was fundamentally impossible. Although, as we stated at the outset, we have found no basic principle ruling out graviton detection, reasonable physics appears to do so…..Certainly, if a “no graviton” law appears elusive, we do feel entitled to predict that no one will ever detect one in our universe.”

    If their analysis is correct, does this confirm Dr. Dyson’s hypothesis that “single gravitons may be unobservable by any conceivable apparatus”? Annoyingly, we must acknowledge that there is a distinction between theoretically impossible and “no one will ever detect one in our universe”. I think it’s only the former that might confirm Dr. Dyson’s hypothesis and justify his sense that a unified theory is impossible. And yet, Rothman and Boughn say only that a “no graviton” law is “elusive”, not that it’s been shown not to exist. And so, demonstrating graviton detection’s “theoretical impossibility” may still occur—how many hundreds of years did it take for Fermat’s Last Theorem to be proven?

    And of course, THAT–the impossibility of a unified theory– is the second, and to me, the more compelling issue raised by Dr. Dyson and Ash’s post. If Dr. Dyson’s hypothesis were confirmed, could you conclude that a unified theory was impossible? I noted one commenter, Bee, who is a theoretical physicist with a blog of her own, is very upset at Dr. Dyson’s speculations, and says, in part, (Comment #12) “This article pains me considerably because I spend my time giving seminars explaining why Dyson’s pessimism is misleading. To find evidence for quantum gravity one doesn’t need to detect single gravitons. The phenomenology of quantum gravity is a thriving research area, thank you very much. One also doesn’t need to detect photons to find evidence for the quantization of electrodynamics.”

    So, even if a “no graviton” law were to be proven, Bee clearly feels it would not present the slightest obstacle to quantum gravity.

    Is she right? Or is Dr. Dyson right?

    Link to this
  39. 39. rloldershaw 8:09 pm 05/5/2013

    In my personal opinion, Bee’s arguments are more convincing here.

    The fact that Dyson is something of a maverick climate change denier does not induce confidence in his reasoning or judgment.

    I do think we are desperately in need of radical new ideas in theoretical physics, but they need to be adequately tested empirically BEFORE we scientifically and emotionally buy into them.

    Discrete Scale Relativity

    Link to this
  40. 40. curiouswavefunction 9:18 pm 05/5/2013

    Thanks all – and especially Barth – for your comments. The post should have been clearer that LIGO is set up for detecting *classical* gravitational waves. As far as I can tell Dyson’s argument is about detecting discrete gravitons which would be a logical consequence of any quantum theory of gravity. Also thanks for pointing out the 2006 paper by Rothman and Boughn. I agree that the hypothesis is a hypothesis, but to me it does seem to at least appear as a strike against discrete graviton detection (it does not prove it’s impossible). And the issue – as a few theoretical physicist friends of mine pointed out – is that detecting gravitons through interferometry is not the only way of validating quantum gravity; detecting Hawking radiation is another way. It’s worth noting that the post is really about two things; pointing out Dyson’s calculation and asking what it would mean for unification. I agree that not being able to detect gravitons using interferometry is not going to hobble efforts for a unified theory per se; what the calculation does is to point out the kind of scenarios that might thwart the search for unification.

    I think the Wikipedia page puts it well: “Unambiguous detection of individual gravitons, though not prohibited by any fundamental law, is impossible with any physically reasonable detector. The reason is the extremely low cross section for the interaction of gravitons with matter. For example, a detector with the mass of Jupiter and 100% efficiency, placed in close orbit around a neutron star, would only be expected to observe one graviton every 10 years, even under the most favorable conditions. It would be impossible to discriminate these events from the background of neutrinos, since the dimensions of the required neutrino shield would ensure collapse into a black hole. Experiments to detect gravitational waves, which may be viewed as coherent states of many gravitons, are underway (e.g., LIGO and VIRGO). Although these experiments cannot detect individual gravitons, they might provide information about certain properties of the graviton. For example, if gravitational waves were observed to propagate slower than c (the speed of light in a vacuum), that would imply that the graviton has mass.”

    The even more fascinating question as far as I am concerned is the following; do you actually believe a theory if its predictions don’t violate any theoretical law but its practical realization is proven to be impossible?

    Link to this
  41. 41. RSchmidt 10:21 pm 05/5/2013

    “The even more fascinating question as far as I am concerned is the following; do you actually believe a theory if its predictions don’t violate any theoretical law but its practical realization is proven to be impossible?” I think the rational answer is, I would believe it is possible. Anything more or less would be faith.

    Link to this
  42. 42. rloldershaw 11:44 pm 05/5/2013

    A prediction that is inherently untestable is not a valid scientific prediction.

    If that is a theory’s only prediction, then the theory cannot be falsified or verified, and therefore the theory is not useful to science.

    Science needs strict predictions/testing or the poor dears wander off into the la-la land of pretty delusions.

    Link to this
  43. 43. m 3:37 am 05/6/2013


    What you are talking about is a hypothesis.

    If for instance a theory gives you an outcome, repeatable and verifiable yet the understanding of say one step in the how it does it is not (well) understood, it is then still a theory. Later on the missing step can be filled in. If the missing step does more than expected then the theory can be expanded to encompass additional variables.

    Link to this
  44. 44. Colour_field splash 10:37 am 05/6/2013

    It may not be possible to make a direct experimental observation of a graviton but an analogous representation of the aether by a fluid dynamical representation may be of use.
    I have used this alternative model to give substance to how a graviton evolves from the field of a circularly polarized electromagnetic field. Thus illuminating the sought after unification of the electromagnetic and gravitational fields.
    The experiments can be viewed on my youtube channel
    The fourth of these videos String theory demonstrated 4: Colour-field splash – a theoretical sketch gives a theoretical sketch of how a graviton may be
    formed from a highly energized circularly polarized photon. The demonstration has a strong link to the Kaluza-Klein fifth dimension, a requirement
    to make general relativity unify electromagnetism with gravity.
    In current theoretical models the extra dimensions are held in a small cylindrical space at each point of space while in my analogous description this
    equates to the small cylindrical nozzle through which the paint flows.

    Link to this
  45. 45. M Tucker 2:47 pm 05/6/2013

    “The even more fascinating question as far as I am concerned is the following; do you actually believe a theory if its predictions don’t violate any theoretical law but its practical realization is proven to be impossible?”

    I would need to keep an open mind. Even though a “practical realization is proven to be impossible” with current technology and understanding I am constantly amazed by the ingenious experiments scientist have so far come up with. Keeping an open mind does not mean to me constructing some sort of belief system to support the reality of an unproven theory. It simply means that I am open to the possibility that it might some day be proven correct. Examples for me are the multiverse, gravitons, the eventual discovery of a more fundamental particle than quarks and leptons to unify the 3 generations of the standard model, Hawking radiation, and proof that information is not lost when a particle enters a black hole.

    I have been keeping an open mind about inflation but the more information we get about the background radiation the more convinced I am becoming that something like Guth’s theory might actually be true.

    Theorists have come up with some very elegant experiments to prove many theories correct in the past so that is why my mind is open.

    Link to this
  46. 46. ars-chemia 5:51 pm 05/8/2013


    According to your paper at arXiv:astro-ph/0011480v2 because of scaling in the cosmos there should be no dwarf stars with a mass of about 0.71 solar mass units because there are no stable nuclei with a mass of 5 atomic mass units. However, extending this out, there are no stable nuclei with a mass over about 200 atomic mass units which would correspond to stars with about 29 solar mass units. But we observe stars with masses of this and higher. How does DSR or SSCM deal with this anomaly?

    Doesn’t this sort of put a nail in the coffin for your theory? Just because things seem to be correlated does not mean that they are.

    Link to this
  47. 47. 3:40 pm 05/9/2013

    What about the argument by heuristic and analogy about the computational basis of reality, that the Dedekind cuts prove the real numbers really exist, and Church’s Thesis, that we need at least two inherently incompatibly different forces to generate a non trivial universe in which the complexity of life and consciousness can exist; in other words the attempt to unify the gravity equations with the unified strong / weak / electromagnetic force equations in a simple point to point distance symmetric to dimensionality single equation is futile????

    Link to this
  48. 48. pkp23 9:25 pm 05/9/2013

    We have debated this at LIGO for a while. The issue at stake might be the “energy” in the graviton, which might or might not depend on the frequency of the gravitational wave, much like photons. There are probably other ways to detect the effects of these gravitons other than LIGO, such as pulsar timing (essentially integrating over stellar scales). My point is that we do not know enough about gravitons to be absolutely certain of this.

    Besides let us detect a whole slew of gravitons first :) . We are almost there, but lets see if even simple things like the plus and cross polarizations containing all the power are accurate or not. We can take it from there. Also my hope is that theory will get there much before experiment has to go through the drastic measure of detecting single gravitons ;) .

    Link to this
  49. 49. Plain-2009 3:12 am 05/10/2013

    What is it that you (or we?) try to unite?

    What we have been able to do so far is to describe faintly the world around us using the powerful language of mathematics.

    But one of these days we will be opening the door to a new hall in the building of physical sciences.

    Take it easy.

    The quest should continue. Nobody around here is tired.

    We do not know how soon that may happen.

    The search should continue.

    Link to this
  50. 50. scienature 8:56 am 05/10/2013

    In the end of 28. mudphud ,9:21 am 05/5/2013 ,he said that “Hopefully at some point someone will propose another theory that includes a prediction of graviton behavior that can be tested.”
    In the end of 28 mudphud, 9:21 am 05/5/2013, he said that “Hopefully at some point someone will propose another theory that includes a prediction of graviton behavior that can be tested”
    I fully agree with this statement. Because in my view, the so-called grand unified theory, but is a branch of the big bang theory. The big bang theory is untenable. Because it is based on the Doppler shift explanation, that light away from the observed redshift is the reflection of. But now the highest redshift value has reached 8.6, which means that the light velocity of that galaxies is close to the speed of light or exceed the speed of light. But this is not possible! Furthermore, often finded that there was collisions between the giant galaxies, like our own Milky way galaxy.It has been a collision between with another galaxy. If there was a big bang, all the stars will be away from each other, how will be these collisions with them? It is a myth!
    So I find. Think of distant galaxies and red shift is gravitational redshifts, redshift is the result after a long time of the tourism the vilosity of photons in the neutrino field. Gravity is the object in the neutrino field mutual occlusion. Is actually the thrust performance of neutrino flow is the mutual attraction. The neutrino field, as I see it, is saying by Einstein as”inertial system”. Test method is very simple: in the earth’s equator, measured a body`s weight at noon and midnight (use spring balance, rather than balance). If the determination of the minimum and maximum value appeared in the very front, the neutrino faster than the speed of light, if than punctual came late, the neutrino speed slower than the speed of light. Of course if and punctuality of coincidence, the two is the same speed.

    This experiment also indirectly proved that the gravitational source between the earth and the sun is the neutrino field.

    Link to this
  51. 51. scienature 9:13 am 05/10/2013

    This experiment is best in the vernal equinox or autumnal equinox.

    Link to this
  52. 52. scienature 11:13 am 05/12/2013

    I think that to the Dyson still should be a good think about it , and then make a decision . Judging from the Michelson – Morley experiment device , you know , the completion of an apparatus like that will not lead to the emergence of a black hole , it is impossible ! You know, quantum mechanics, there are a lot of law is the lack of proper understanding of representation of fact , often mistaken for those who can not pick them up the actual test case ! Here is a very obvious example.

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  53. 53. Quinn the Eskimo 11:14 pm 05/12/2013

    Each poster presents the truth. With supportive arguments and many with references. Others dispute, equally eloquently and concisely.

    Surely we are in the dark ages of Physics. Otherwise why would we need the bright light of the LHC???

    Link to this
  54. 54. Dr. Strangelove 3:12 am 05/14/2013

    “do you actually believe a theory if its predictions don’t violate any theoretical law but its practical realization is proven to be impossible?”

    IMO you can believe it if it’s the best explanation for observed phenomena. Scientists believe the theory of evolution though you cannot conduct experiments to prove it. If two or more theories equally explain observed phenomena and it’s impossible to verify by experiments which one is true, you have to apply Occam’s razor. Choose the simplest one with minimum assumptions.

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  55. 55. Dr. Strangelove 4:02 am 05/14/2013

    BTW theories exist only in our mind. They are just representations of reality. Only observations are objective reality. We don’t discover theories, we invent them. So strictly speaking, scientific theories are impossible to prove. You can only disprove them.

    Link to this
  56. 56. verdai 3:13 pm 06/15/2013

    similar to the Darks.

    Link to this
  57. 57. Author Frank DiMeglio 5:17 pm 11/17/2013

    Here are the reasons why the search for a unified theory has come up empty handed:


    A falling man feels no gravity. The Universe is either contracting OR expanding.

    CLEARLY, the problem with Einstein’s theory of gravity is as follows.

    Einstein never could explain gravitational and inertial equivalency and balancing. The modern physicists, in fact, admit that none of them can quite explain it. T…hat is a fact that is admitted to.

    Einstein could never unite gravity and electromagnetism. Einstein never truly, basically, and fundamentally incorporated or explained instantaneity in his ideas either.

    Ultimately, position and position relative to distance in/of space have to BOTH be accounted for. Visible and invisible space must be in fundamental and ultimate equilibrium and balance.

    Regarding outer space, it is black; there is weightlessness; and we are not touching anything. Think about it. Outer space precludes and destroys our being, experience, and vision. In fact, we do not and CANNOT fully, directly, and truly/really/actually EXPERIENCE OUTER SPACE AS IT IS (including seen, felt, AND touched).

    Now, the falling man doesn’t involve space as it is seen, felt, AND touched in conjunction with balanced and stabilized distance in/of space either.

    Physics and physical experience is fully and truly understood as it is seen, felt, AND touched. Indeed, we always begin with typical, shared, necessary, foundational/fundamental, ACTUAL/REAL, and ordinary experience(s) in establishing physical fundamentals and truths.

    The fundamental equivalency and balancing of gravity, inertia, and electromagnetism fundamentally and certainly involves us. This ALSO involves instantaneity in conjunction with half inertia and half gravity, stabilized and balanced distance in/of space, invisible and visible space in FUNDAMENTAL equilibrium and balance, and the MIDDLE distance in/of space. It all makes perfect sense.

    The above paragraph perfectly (and consistently) desribes the fundamental, theoretical, and ultimate requirements of unification of physics and physical experience. In fact, I have thoroughly and clearly proven that this fundamental, linked, natural, necessary, ultimate, and theoretical unification of physics (including actual physical experience) takes place in/as dream experience.

    Dream experience grows and increases, and dream experience is seen, felt, AND touched. Importantly, there is no outsmarting the genius of dreams.

    In dreams, we are conscious and alive in conjunction with the linked, separate, fundamental, and necessary experience of our growth and becoming other than we are. This necessarily and clearly involves a fundamental balance of being and experience in conjunction with the essential mastery of physics and physical experience.

    Importantly, dream experience IS possible/potential AND actual.
    Moreover, dreams fundamentally involve (and balance) the super important relation of something and nothing.

    What I have proven is NOT a theory. It is truth. It is the ultimate, fundamental, natural, extensive, balanced, actual, AND theoretical unification of physics and physical experience.

    Do any of you think that any of the mainstream, modern, academic physicists can contradict or disprove what I have written here? Not hardly. Can they show that it is inconsistent or incomplete? Can they contradict it with something that is truly, fundamentally, and extensively its equal? No, they can’t; and they never will be able to.

    Link to this
  58. 58. chosenygrace 4:34 am 02/25/2014

    “Darwin’s theory is a perfect illustration of this fact”

    God this God that say the atheists of Christians, yet anti-Christian atheists never shut up about evolution, injecting it into everything where it doesn’t belong, trying to score points with their “peers”, mocking Christians by making these statements they know to be absurd and false. The theory is not a perfect anything of A FACT, because it is a theory, and one that was disproved. Grow up, mockers. You are conniving morons with narcissistc personality disorder, practiced at being malicious.

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