Alternative theories to General Relativity - great opportunity

In summary, Gravity Probe B is a space mission that is set to launch on Monday, 19 April, 2004 after many years of development. It aims to provide tests for two unverified predictions of Albert Einstein's general theory of relativity. Some members of the forum have difficulties with general relativity and have proposed alternative theories, but this mission presents an opportunity to make history. The results of the mission are highly anticipated, with some predicting that it will confirm or challenge the predictions of general relativity. Some theories suggest that the graviton, if it exists, is a spin-2 boson and cannot be detected, while others propose that space is made up of equal numbers of gravitons and antigravitons forever
  • #1
Nereid
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Gravity Probe B is due to be launched on Monday, 19 April, 2004. Many years in development, it is intended to provide good tests of "two extraordinary, unverified predictions of Albert Einstein's general theory of relativity."

Many posters to PF have difficulties with GR; several have proposed alternative theories.

Now is your chance to make history!

What do you predict the results of Gravity Probe B will be? How do your predictions differ from those of GR?
 
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  • #2
The graviton as a boson cannot be detected. As a fermion, the graviton takes the properties of fermion and not distinquishable from other existing fermions. All existing bosons contain even multiples of the graviton and can have odd or even multiple of the antigraviton. The graviton and its antiparticle are distinguishable in theory but cannot be verified by any experiment.

Space is made up of equal number of graviton and antigraviton. Graviton is the ying and antigraviton is the yang of space. They are forever linked and require infinite energy to break this bond. The link is really a path to another universe.
 
  • #3
Antonio, a curious feature of physical predictions is that they involve numbers.

- Warren
 
  • #4
Antonio Lao said:
The graviton as a boson cannot be detected.

But the Gravity Probe B doesn't promise to be a test of quantum gravity. It promises to be a test of classical gravity.

As a fermion, the graviton takes the properties of fermion

The graviton, if it exists, is a spin-2 boson.

All boson, all de time.

and not distinquishable from other existing fermions.

Who said the various fermions were indistinguishable? They all have different quantum numbers.

The rest is just too bizzare, so I'll skip it.

To all: I think what is being sought after here is the predictions of an alternative theory that has field equations.
 
  • #5
The number all experiments are searching for is whether it's zero. When it's exactly zero then it's not a number anymore just like infinity. When it's not zero then further experiments are needed to keep the searching process lively.

Why spend all that money just for classical test of gravity? Maybe the scientists believe that classical testings can indirectly answer some quamtum gravity's question?
 
  • #6
Zero is most certainly a specific number. Its not like infinity.
 
  • #7
Thanks. I thought so too at first. But I can't seem to figure out why there is "zero" force? "Zero" force implies that force does not exist. To me, "zero" force can also implies the equilbrium of forces which vector addition is F1 + F2 = 0 implies the existence of a force -F1, F2 = -F1, whose magnitude is the same as F1 but the direction is "opposite."

So when an experiment fails to detect a force, it does not really mean that the force does not exist. It can also mean that there exist an "opposite" force equal in magnitude but "opposite" in direction.

When it comes to the idea mass being "zero" such as photon, and gluons except for W's and Z's, the "zero" mass of photon can implies two types of "vector" mass that when added equally is "zero." These are the potential mass and the kinetic mass. The mass of fermions are potential and the mass of pure boson are kinetic mass. Total mass = p-mass + k-mass.
 
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  • #8
I do have a pet theory regarding the cause of gravitation, but as yet I cannot find a way to apply this idea so that it makes a prediction that is diiferent from the predictions of standard GR. I suppose that makes it an interpretation or view, rather than a true theory. The crux of this idea is that gravity is indeed a warping of spacetime caused by the presence of matter. However, I propose the possibility that the phenomanon we refer to as matter is the intersection of hyperdimensional objects with our 3-dimensional universe.

My favorite analogy of this involves using the 2-dimensional surface of water as the symbolic representation of our universe. When an object passes through this suface, the surface is curved in a direction orthagonol to the two directions it normally posses. This curvature represents the imageb of gravity presentsed by GR.

But I can't seem to take it from "interpretation" to "theory". Can anyone think of a prediction based on this view that would be at variance with a classical GR prediction?
 
  • #9
I don't think the predictions of GR will be found to be wrong on this mission because
the probe is not testing predictions related to high mass densities and small distance scales.
GR must be incomplete - the current universe could not have come out of a singularity.
I don't think that the Earth drags space time with it as it moves -it is probably dragging vacuum particles with it through space and time just as a tennis ball has a layer of air attached to it.If GR is to be compatible with QM then matter must cause
particles to follow curved paths by exchange of force carriers, but not in itself curve space.Perhaps the Earth has a dense area of compressed vacuum particles on the front half which is colliding with the vacuum and a lower pressure area of rarefied vacuum particles on the back half.These areas would cause differences in measured gravitational force.
 
  • #10
Antonio Lao said:
Thanks. I thought so too at first. But I can't seem to figure out why there is "zero" force? "Zero" force implies that force does not exist. To me, "zero" force can also implies the equilbrium of forces which vector addition is F1 + F2 = 0 implies the existence of a force -F1, F2 = -F1, whose magnitude is the same as F1 but the direction is "opposite."

So when an experiment fails to detect a force, it does not really mean that the force does not exist. It can also mean that there exist an "opposite" force equal in magnitude but "opposite" in direction.
Ok, so you do understand that there is a difference between "zero force" and "no force," ie, "zero force" may mean either no forces are present or all forces are in equilibrium. Either way, zero is sill a number. So, what is the problem?
 
  • #11
I predict Gravity Probe B will discover the existence of the Icky Goo Medium which is invisible sticky stuff that keeps the stuff in space stuck to each other something like long strings of rubber cement that never dries cause there's no air in space. As far as numbers for my prediction; it goes for about $1.79 a bottle these days.
 
  • #12
The problem is "zero" does not tell us which is which. No force or equilibrium. It's a number with a double meaning or we can say with infinite meanings leading one to conclude the existence of infinite solutions. It's nonlinearity at its purest form.

The field equations of general relativity is nonlinear. There exist infinite solutions hence infinite models for the universe and the expansion model is just one of them and it seems to be the one which do agree with experiments.
 
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  • #13
Antonio Lao said:
The problem is "zero" does not tell us which is which. No force or equilibrium. It's a number with a double meaning or we can say with infinite meanings leading one to conclude the existence of infinite solutions.
How is that any different from any other number? A net force of 1N can be achieved in an infinite number of ways as well: 2-1=1, 3-2=1, 4-3=1, etc...
 
  • #14
Zero is useful in many ways to many people. But I won't need it for the research I'm working on.

If zero is used unwisely, it has the power to destroy logic. Please see page 217-219 of Charles Seife's book on Zero, the biography of a dangerous idea.
 
  • #15
Further investigations lead me to understand that the main purpose of GPB experiment is again to find the existence of the ether (a frame of rest).

The nonexistence of the ether was proved by MM null experiment.

The assertion is that there is no such thing as a "rest" frame of reference. Everything is in a state of motion (oscillation, vibration, spinning, etc). The GPB hopes to find the spinning of spacetime at the local infinitesimal region of spacetime.

But in my research, this spinning is more of a double spins configuration. If this two spin vectors are equal in magnitude and exactly opposite then GPB will still fail to detect the wobbles and precession. But if these two spins are not equal in magnitude or not exactly opposite in direction or both then there is a chance GPB will be able to detect the wobbles and precession of spacetime.
 
  • #16
I predict that the universe will turn out to have a large scale structure for gravity purposes equivalent to a 10^55 megatons explosion in a pre-existing vacuum, similar to a nuclear explosion in space (the universe obviously has a different mechanism during the first 3 minutes to a fission bomb, however I am here talking about later times). The universal gravitational constant will turn out to be G = 75% of the square of the Hubble constant divided into the product of the density of the universe and pi. The cause of gravity will be, as proved, the outward motion of matter in the big bang causing an opposite reaction of the fabric of the continuum of space, flowing around it to fill in the vacated volume. (http://members.lycos.co.uk/nigelbryancook/)

By analogy is the reaction of water to a moving underwater submarine, or the air displaced around a moving person filling in the vacated volume. The continuum of space flows around particles of matter like electrons, giving the very small waves of wave-particle duality.

Space pressure towards us from all directions is slightly shielded by the planet Earth and other masses. Hence, the net space pressure pushes people downwards, causing things to fall; gravity! This proof predicted that the furthest stars would not be gravitationally slowed; later observed from supernova red-shifts.
 
  • #17
Is the reality of spacetime really four dimensional? The space part of spacetime contains dimensional levels that are bounded by zero-infinity.

The boundary between one dimension and two dimensions of space is a Sierpinski carpet.

The boundary between two dimensions and three dimensions of space is a Menger sponge.

Are physical area and volume just pigments of our imagination hence are all illusions?

Is one dimension of space the only physical reality?

Physical area (two dimensions) leads to wave nature of reality and physical volume (three dimensions) leads to particle nature of reality.

So the universe is just an infinitely long flexible line with waves and particles as kinks and knots along this line.
 
  • #18
Is one dimension of space the only physical reality?
It's certainly the simplest model and the most appealing!
It would mean angles are an illusion . But what do you replace them with?
 
  • #19
Angles (whether ordinary angles of plane geometry/trigonometry or solid angles of solid geometry and spherical trigonometry) are used to define rotation (implying the need of a coordinate system or frame of reference) and indirectly made to clarify the concept of direction. In wave physics, the angles take the form of phases. When some waves are in phase it means they have the same angle in an abstract multidimensional configuration space.

But if we assumed the quantization of one dimensional space as the existence of a Local Infinitesimal Motion (LIM) and together with the properties (there are eight of them) of the principle of a directional invariance, we can described higher dimensional objects (area and volume) without the use of angles and any coordinate system.
 
  • #20
I've done a calculation using George Luis le Sage's theory of pushing gravity.
It says that a photon will be blueshifted when it "falls" in the Earth's gravitational field
by 1.00001 times more on the side of the Earth shaded from the Sun than on the side of the Earth facing the Sun.Gravity probe B won't be able to measure the difference
but when the mossbauer effect can be measured 10 times more accurately, it will!
 

1. What is the main difference between General Relativity and alternative theories?

The main difference between General Relativity and alternative theories is the fundamental concept of gravity. In General Relativity, gravity is described as the curvature of space-time caused by massive objects, while alternative theories propose different mechanisms for gravity such as extra dimensions or modifications to the law of gravity.

2. Are there any experimental evidence for alternative theories to General Relativity?

There have been several experiments conducted to test alternative theories to General Relativity, but so far, none have provided conclusive evidence to disprove General Relativity. However, some alternative theories, such as Modified Newtonian Dynamics (MOND), have been successful in explaining certain observations that General Relativity cannot, such as the rotation curves of galaxies.

3. How do alternative theories to General Relativity affect our understanding of the universe?

Alternative theories to General Relativity challenge our current understanding of the universe by proposing different explanations for gravity and the structure of space-time. They also offer new perspectives on topics such as dark matter and dark energy, which are still not fully understood within the framework of General Relativity.

4. Can alternative theories to General Relativity be reconciled with other theories in physics?

While some alternative theories to General Relativity can be reconciled with other theories in physics, such as quantum mechanics, others may require significant modifications or may be incompatible with certain principles of other theories. This is an ongoing area of research and debate within the scientific community.

5. Is there a need for alternative theories to General Relativity?

There is ongoing debate about whether there is a need for alternative theories to General Relativity. While General Relativity has been incredibly successful in explaining a wide range of astronomical observations, there are still some unresolved issues, such as the discrepancy between theoretical predictions and observations of the expanding universe. Alternative theories provide a different perspective and may offer solutions to these unresolved issues.

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