RE: Maggie McKee, Fast-spinning star could test gravitational waves, New Scientist, 22 February 2005,
http://www.newscientist.com/article.ns?id=dn7052

"There is controversy over the gravitational wave idea [as a brake on
pulsars], but is it is eminently testable," says Chakrabarty. "If it's
right, Advanced LIGO will see gravitational waves at a certain level. If they don't see it, the theory is dead."
 

Dear Professor Chakrabarty,

I'm afraid LIGO was born dead, in much the same way as the Superconducting Super Collider. The so-called ripples of spacetime metric or gravitational waves cannot be detected *in principle*,

http://www.God-does-not-play-dice.net/Kopeikin.html#note_2

http://www.God-does-not-play-dice.net/Price.html

The sole difference between the two projects is that the Advanced LIGO, with "improved sensitivity", is relatively cheaper than the
Superconducting Super Collider and its current incarnation,

http://www.God-does-not-play-dice.net/LHC.html#summary

http://www.God-does-not-play-dice.net/PPARC.html

All this boils down to satisfying the obsessions of people like Barry
Barish,

http://psr.rice.edu/ligo_cost.html

"Robbie Vogt, a physicist at Caltech and LIGO's founding-father, was replaced by Barry Barish, a high-energy physicist with experience in managing large parts of the now-defunct Superconducting Super Collider."

With taxpayers' money, however.

I think this is pathetic.

Moreover, people like Bruce Allen have organized the so-called
Einstein@home project, and currently over 50,000 people around the world are helping in the hunt for the so-called gravitational waves. See

Maggie McKee, Thousands join hunt for gravitational waves, New
Scientist, 14 March 2005,
http://www.newscientist.com/article.ns?id=dn7139

Neither Bruce Allen nor Barry Barish or ANY of the LIGO scientists have mentioned the research by Prof. Angelo Loinger, who have proved that the hypothetical gravitational waves cannot exist *in principle*,

http://www.God-does-not-play-dice.net/Loinger.html

The proof has been delivered first by Hermann Weyl in 1944, but nobody from LIGO is interested. See the link above for references.

Let me stress that everything said in this email about GWs can be
immediately converted into rigorous mathematical proof. See again the papers by Prof. Angelo Loinger at the link above.

I will be happy if you raise your voice and write to NSF and other
government funding institutions in your country, which support the
obsession of LIGO people. If they want to verify their obsessions, let them do that with their own cash.

Last but not least, LIGO people should never involve Albert Einstein. He was an honest person, and would have never said half of the truth to the lay audience.

Sincerely yours,

Dimi Chakalov
--
http://www.God-does-not-play-dice.net
http://www.God-does-not-play-dice.net/download.html
 

===========

Subject: Advanced LIGO
Date: Tue, 22 Mar 2005 06:36:31 +0200
From: Dimi Chakalov <dimi@chakalov.net>
To: David Shoemaker <dhs@ligo.mit.edu>
CC: schutz@aei.mpg.de, jim@newton.uoregon.edu,
     cmw@howdy.wustl.edu, siemens@gravity.phys.uwm.edu,
     pullin@lsu.edu, shane@gravity.psu.edu,
     gwastro-sci@gravity.psu.edu, ballen@gravity.phys.uwm.edu,
     barish@ligo.caltech.edu, weiss_r@ligo.mit.edu,
     sanders_g@ligo.caltech.edu, kats@ligo.mit.edu,
     office-hannover@aei.mpg.de
 

Dear David:

In MOG-25, gr-qc/0503086 v1, p. 8, you wrote:

"A closing note on this choice is that, since the internal thermal noise is considered to be quite low for fused silica, any extra improvements in coating thermal noise will lead to similar improvements in the Advanced LIGO sensitivity. A nice challenge!"

I'm afraid thermal noise coating may not help you detect GWs,

http://www.God-does-not-play-dice.net/Chakrabarty.html

There is a really nice challenge from H. Weyl and A. Loinger at

http://www.God-does-not-play-dice.net/Loinger.html

Should you or your colleagues have questions, please don't hesitate.

Sincerely,

Dimi Chakalov
--
http://www.God-does-not-play-dice.net
http://www.God-does-not-play-dice.net/download.html
 
 

Note 1: Let me write a few brief notes on GWs, which are intended to graduate students studying GR, such as those taught by Prof. Marc Kamionkowski. If you are familiar with the subject, you may skip these problems, they are well-known since the inception of Einstein's GR.

In addition to the papers by Hermann Weyl and Angelo Loinger, note that the physicists above do not consider the so-called gravitational waves (GWs) as something resembling the empty waves (de Broglie waves propagating in Minkowski spacetime; cf. F. Selleri, On the direct observability of quantum waves, Found. Phys., 12 (1982) 1087-1112). On the contrary, they deeply believe that GWs are capable of interacting with physical bodies. Specifically, they believe the perturbation of spacetime metric might be sinusoidal in nature, and calculate the much-desired (and still unobserved) effect as due to the quadrupole radiation; more from Clifford Will here.

Here's a brief list of unsolved mysteries.

1. How could GWs propagate within themselves, and with respect to themselves? (Kip Thorne keeps quiet, since March 2003.) Hint: pin down the amplitude of GWs, bit don't "collapse" it à la von Neumann and Born, because you will need it to display the sinusoidal propagation of GWs within themselves and with respect to themselves.

2. What will be the duration of the interaction of GWs with LIGO? If it's "instantaneous", like the "collapse" in QM, we're talking parapsychology.

3. If it isn't instantaneous, please write down the conservation equations for the energy of GWs for this finite time interval, and explain the conversion of the "energy" of GWs into something that you know from classical physics and/or QFT. Hint: don't miss the graviton.

4. After completing all the tasks above, you will be able to say something on the nature of dark energy, since it is the only entity that can (supposedly) alter the spacetime metric. Only its physical nature is very, I mean, very dark.

Of course, there are compelling evidence that GWs exist, as the readers of Scientific American know very well. I'm not saying that GWs do not exist. On the contrary, both GWs and quantum waves are bona fine empty waves "traveling" in the global mode of spacetime. These empty waves can contact the local mode of spacetime only through the apex of Minkowski cone, however. Thus, they are unobservable with LIGO, LISA, tarot cards, crystal balls, or Big Bang Observer, regrettably. You need a brain to detect the "unzipped" virtual reality of gravity. It's an old story.
 

D. Chakalov
March 22, 2005
Last update: April 19, 2005
--
We haven't the money, so we've got to think!
Lord Rutherford, 1962 Brunel Lecture, 14 February 1962

=============
 
 

Note 2: Let me quote from AEI web site: "Additionally, the GW group plays an active role in LISA, a planned space-based gravitational wave detector (currently scheduled to fly in 2013) that will be built jointly by ESA and NASA. Karsten Danzmann (Director of the AEI Division of Laser Interferometry and Gravitational Wave Astronomy) is co-Chair of the LISA International Science Team, and both Schutz and Cutler are also on this team."

On Thursday, March 31, 2005, Bernard F. Schutz delivered an one-hour talk "The inevitability of gravitational waves" (15:45-16:45) at "SPACETIME IN ACTION: 100 YEARS OF RELATIVITY" (Pavia, March 29 - April 2 2005).

On the next day, A. Ashtekar gave his Public Lecture "Space and Time: From Antiquity to Einstein and Beyond". The last slide of Ashtekar's talk reads the following: "We already have fascinating glimpses through Quantum Geometry. Breakdown of the continuum is a radical paradigm shift because all physical theories presupposed it! In particular, it reshapes the question we can meaningfully ask about The Beginning and The End!"

Abby Ashtekar must have been really excited, since he seldom uses exclamation marks. Thirteen years ago, in July 1992, he explained the crux of the problem (gr-qc/9302024): "The probabilities for an exhaustive set of mutually exclusive alternatives should add up to one. In quantum mechanics, this is generally ensured by using an instant of time to specify such alternatives. What is one to do when there is no time and no instants? These are fascinating issues."

Needless to say, Ashtekar's "fascinating glimpses through Quantum Geometry", launched under the stipulation that the topology of time should be either cyclic or linear (slide 39, "Is Time Cyclic or Linear?"), didn't solve the problem above, but produced a number of exclamation marks and a peculiar statement (slide 42): "Quantum theory of Geometry developed primarily at the Center for Gravitational Physics and Geometry at PSU. Now used by research groups world-wide." Coincidently or not, his Public Lecture was reserved for April 1st.

Let's go back to Bernard F. Schutz' talk "The inevitability of gravitational waves". I sent him two very polite requests, by email, for a copy from the paper (if any) of his talk, but he didn't reply. Judging from Bernard Schutz' slides 5, 6, 10, and 18, his talk hasn't been essentially different from his article on gravitational radiation published five years ago [Ref. 1], hence I will comment on the latter.

In addition to the tasks mentioned above, in order to detect these mythical gravitational waves, we need to sort out a number of "fascinating issues". All of them en bloc.
 

T1. Localization of energy in GR: "Energy is localized only in regions, not at points" [Ref. 1]. It is real energy, as Bernard Schutz says, but he failed to explain the puzzle known as "non-locality" of gravitational energy. More from Hermann Weyl and Laszlo Szabados.
 

T2. The shift from dipole to quadropole approximation is highly deceptive: "As in electromagnetism (Sic! - D.C.), the amplitude of the radiation is proportional to the second time-derivative of Q_jk" [Ref. 1]. However, unlike electromagnetism, you need to single out the "projection" of the transverse axis [Ref. 1] on your region (T1) affected by those mythical tidal forces. This isn't some "xy-plane", as stated by Bernard Schutz. This is 3-D space. How do you measure the duration of the metric perturbation of 3-D space? With respect to what? Truly fascinating tasks, à la Ashtekar.
 

T3. Define the "region" (T1) in which your wristwatch can read this "second time-derivative of Q_jk" (T2), and prove that you are not trying to "measure" the dark energy but the "real energy" of GWs. Alternatively, prove that you are indeed trying to measure the “dark side of the Universe”, as stated by Bernard Schutz in his talk "The inevitability of gravitational waves", slide 18: "96% of the Universe is incapable of emitting light or other electromagnetic radiation, so GWs are our only window into what Kip Thorne calls the “dark side of the Universe”."
 

If you're still alive and well, and do not encounter any catastrophic events by measuring the "wobbling" dark energy, shave and pack your luggage, since you'll be very soon invited in Stockholm to collect your Nobel Prize.

Again, I'm not saying that gravitational waves do not exist. It's not that simple. Please read above.
 

D. Chakalov
April 27, 2005, 20:11:54 GMT
 
 
 

[Ref. 1] Bernard F. Schutz, Gravitational Radiation, AEI-2000-020, gr-qc/0003069 v1. Accepted by Encycopedia of Astronomy and Astrophysics, 2000.

"In general relativity, Einstein used the principle of equivalence as the basis for a geometrical description of gravity. In the four-dimensional world of space-time, the trajectory of a particle falling freely in a gravitational field is a certain fixed curve. Its direction at any point depends on the velocity of the particle. The equivalence principle implies that there is a preferred set of curves in space-time: at any point, pick any direction, and there is a unique curve in that direction that will be the trajectory of any particle starting with that velocity. These trajectories are thus properties of space-time itself.

"Moreover, if there were no gravitational field, the trajectories would be simple straight lines. Even in a gravitational field, a small freely falling particle does not "feel" any acceleration: its internal state is the same as if there were no gravity. Therefore Einstein postulated that a gravitational field made space-time curved, and that the preferred trajectories were locally straight lines that simply changed direction as they moved through
the curved space-time, in much the same way as a great circle on a sphere changes direction relative to other great circles as one goes along it. For weak gravitational fields of slowly moving bodies, Einstein’s theory reduces to Newton’s in the first approximation.

"For gravitational waves, one could make a very simple detector just by monitoring the distance between two nearby freely falling particles. If they are genuinely free, then any changes in their separations would indicate the passage of a gravitational wave. Because this measures a tidal effect, the bigger the separation of the particles, the bigger will be the change in their separation, at least for particles that are separated by less than a gravitational wavelength. Most modern gravitational wave detectors are designed to be as big as cost and practicality allows.
...

"The question of energy in gravitational waves is still a delicate one. There is no question that waves carry energy (and momentum) away from their sources. Nevertheless, it is not possible in general relativity to localize the energy in the radiation to regions smaller than about a wavelength. Indeed the equivalence principle shows that "point" particles feel nothing, no matter how strong the wave. The wave only acts by stretching space-time, producing a tidal distortion in the separations between particles (see the discussion of polarization below).

"For this reason, energy is localized only in regions, not at points. It is nevertheless real energy: the nonlinearity of general relativity allows waves to create gravitation themselves.
...

"Energy flux carried by waves

"The energy in the waves can also be estimated from these equations and general physical principles. Quite generally, in classical field theories, the energy flux of a propagating sinusoidal plane wave is proportional to the square of the time-derivative of the fundamental field. In electromagnetism, the Poynting flux is proportional to the square of the time-derivative of the vector potential.

"In general relativity, the flux is therefore proportional to the square of the time-derivative of h(t). The proportionality constant must be built only out of c, G, and pure numbers.
...

"The calculation and equations in this section have been framed within a modified Newtonian model of gravity with a propagation speed of c, and one would expect some differences from general relativity. The most important difference is in the direction in which the tidal forces act. In the simple model, wave accelerations act in the z-direction, which was the direction of propagation of the wave. This is called a longitudinal wave.

"In general relativity, gravitational waves are transverse waves: if the wave propagates in the z-direction then the tidal forces act only in the xy-plane. We will discuss later the exact form that their action in this
plane takes.
....

p. 6: "Quadrupole approximation

"Again in electromagnetism, the dipole moment is defined as the integral

[XXX]

where [p] is the charge density and x_i is a Cartesian coordinate. If this integral is time-dependent, then the amplitude of the electromagnetic waves will be proportional to its first time-derivative dd_i/dt, and the radiated energy will be proportional (as we remarked earlier) to the square of the time derivative of this amplitude, i.e. to [XXX].

"In the post-Newtonian approximation to general relativity, the calculation goes remarkably similarly. The monopole moment is now the total mass-energy, which is the dominant source of the gravitational field for
non-relativistic bodies, and which is constant as long as the radiation is weak. (Radiation will carry away energy, but in the post-Newtonian approximation that is a higher-order effect.) The dipole moment is given by the same equation as above, but with [p] interpreted as the density of mass-energy.

"However, here general relativity departs from electromagnetism. The time-derivative of the dipole moment is, since the mass-energy is conserved, just the integral of the velocity v_i:

[XXX]  (10)

"But this is the total momentum in the system, and (to lowest order) this is constant. Therefore, there is no energy radiated due to dipole effects in general relativity.

"The gravitational field far from the source does contain a dipole piece if d_i is non-zero, but this is constant because it reflects the fact that the source has non-zero total momentum and is therefore moving through space.

"To find genuine radiation in general relativity one must go one step beyond the dipole approximation to the quadrupole terms.
...

"A gravitational wave in general relativity is represented by a matrix h_jk rather than a single scalar h, and its source (in the quadrupole approximation) is Q_jk.

"As in electromagnetism, the amplitude of the radiation is proportional to the second time-derivative of Q_jk, and it falls off inversely with the distance r from the source. 

"A factor of G/c⁴ is needed in order to get a dimensionless amplitude h, and a factor of 2 to be consistent with the definition in Equation (8). The result for h_jk is:

[XXX]   (12)

"General relativity describes waves with a matrix because gravity is geometry, and the effects of gravity are represented by the stretching of space-time. This matrix contains that distortion information. Here is the information about the transverse action of the waves that the quasi-Newtonian model of the last section did not get right.
....

p. 11: "Observations of the gravitational waves emitted by a wobbling horizon or by a particle in orbit around a black hole have the potential to test the uniqueness theorem and thereby to verify the predictions of general relativity about the strongest possible gravitational fields.
...

p. 13: "If gravitational wave astronomy follows the example of other fields, like X-Ray Astronomy and Radio Astronomy, then at some level of sensitivity it will begin to discover sources that were completely unexpected. Many scientists think the chance of this happening early is very good, since the processes that produce gravitational waves are so different from those that produce the electromagnetic radiation on which most present knowledge of the universe is based, and since more than 90% of the matter in the universe is dark and interacts with visible matter only through gravitation."