It's Einstein versus Newton again

June 13, 2012
Researchers proved that the two predictions for the balls trajectory can rapidly diverge and become completely different if the motion of the ball is chaotic

A simple bouncing ball has reignited a debate long thought settled: whose landmark physics theory is correct – Albert Einstein’s general relativity theory or Sir Isaac Newton’s theory of gravity?

Associate Professor Lan Boon Leong and Liang Shiuan-Ni, researchers from the School of Science at Monash University Sunway campus, showed with a system comprising a steel and a concave lens that the predictions of the two theories do not always agree, as conventionally expected.

In a paper published in April, the researchers proved that the two predictions for the ball’s trajectory can rapidly diverge and become completely different if the motion of the ball is chaotic.

So if the predictions are different, who is right?

Developed by the researchers, the system had the ball bouncing on a lens which was attached to the oscillating membrane of a loudspeaker. In between impacts with the lens, the ball underwent free-fall motion due to gravity (as long as the setup was housed in a vacuum chamber).

“It is very difficult to accurately calculate the ball’s trajectory using the two theories for comparison with experiment because the parameters and initial conditions of the system must be known very accurately when the motion is chaotic," Dr Lan said.

“However, since general relativity has withstood other experimental tests over the century, one would expect the general-relativistic prediction to be empirically correct. This would mean that even for low-speed weak-gravity systems, general-relativistic mechanics must generally be used, instead of the standard practice of using Newtonian mechanics to correctly study their dynamics."

Dr Lan said this paradigm shift may well lead to new understandings and discoveries for such systems.

"On the other hand, if the Newtonian prediction is correct, Einstein would surely turn in his grave. His would need to be corrected in the low-speed weak-gravity limit," Dr Lan said.

"Either way, there is new physics to be explored."

Explore further: Do we need dark matter?

More information: 1. PDF:

2. Liang S-N, Lan BL (2012) Comparison of Newtonian and Special-Relativistic Trajectories with the General-Relativistic Trajectory for a Low-Speed Weak-Gravity System. PLoS ONE 7(4): e34720. doi:10.1371/journal.pone.0034720

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1 / 5 (5) Jun 13, 2012
2 theories.. yet there can be only one true one.

I can't wait for the standard model to be rebuilt.. it is painfully obvious that it is fundamentally lacking.
1 / 5 (3) Jun 13, 2012
I'm not sure if the rebuilding of Standard Model will help you in solving of macroscopic situations...;-) I presume by now, you've some idea of what the SM is about..
5 / 5 (3) Jun 14, 2012
S... I must agree with "water ripples"! :(

Stupid article. They don't even speak about results or anything. Bullshit...
5 / 5 (6) Jun 14, 2012
Poor Article. GR and Newton only produce similar results. Exceptionally similar results in low velocity, low mass situations.

If you devise a test sensitive enough you can still determine the difference between the two irrespective of how slow or little mass the system has.

Poor statements from a poor article.

The only novel concept here is that chaos can be exploited to distinguish between two very similar systems.
not rated yet Jun 14, 2012
IMO the point of this article is, under certain situations the Newtonian model is unstable and the relativistic not. The Newtonian mechanics is very idealistic. For example, when we hit the stone with the hammer, then the inertial force becomes infinite, if we neglect the elasticity of material during impact. In relativity there is always speed of light, which limits the inertial force in the system. Some mechanical systems are more sensitive to this idealization than the others. For example the double pendulum, the formal solution of which faces with instability because of high inertial forces in this system. The relativity vanishes these instabilities due the finite speed of propagation forces along hinges of pendulum. In reality the pendulum is way less chaotic because of elasticity of hinges and various looseness of its bearing.
not rated yet Jun 14, 2012
IMO when we consider the elasticity of the material, then we actually consider the relativistic effect on background, i.e. the finite speed of light in highly hyperdimensional system formed with nested systems of electrons revolving the atoms vibrating in the lattice. The speed of light is lowered into speed of sound in this system due the spontaneous symmetry breaking and decomposed to various tensor components there.
1 / 5 (5) Jun 14, 2012
By the way, we known that Einstein gravity gives a better prediction than Newton because of its relativistic effect, but the problem is that we do not know how and why it works, i.e. what is its mechanism? May be this unconventional view could give some hint.
5 / 5 (1) Jun 17, 2012
ill be shifting my paradigm once they've done a million steel ball rolls and THEN seek the headlines, before that its just hot air.
1 / 5 (1) Jun 17, 2012
Dr Lan is making a really poor argument. He seems to be saying that since both theories predicitions diverge (from each other) that we must accept one because its been tested in other situations. Which is stupid, because BOTH have been tested in other situations and the limitiations of Newtownian physics are well measured and negligible in low mass low speed (LMLS) situations.
The introduction of a chaotic system is irrelevent unless you can demonstrate that in chaotic sensitive dependenance on initial conditions (SDIC) situations GR gives better results than NM, which is not shown.
Im not arituclating the problem very well, but essentially this is worthless psuedoscience.

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