A recent research reveals credible analysis of the orbital movements of
long-period, widely spaced binary stars, commonly known as wide binaries in
astronomy and astrophysics, that provides strong evidence for the breakdown
of normal gravity at the low acceleration limit.
Up to 26,500 broad binaries within 650 light years (LY) were employed in
the work by Kyu-Hyun Chae, professor of physics and astronomy at Sejong
University in Seoul, who used data from the Gaia satellite observatory. The
Astrophysical Journal's edition for August 1, 2023, has the study's
publication.
Chae's study concentrated on computing the gravitational accelerations
experienced by binary stars as a function of their spacing, or alternatively
the orbital period, through a Monte Carlo deprojection of observed
sky-projected movements to the three-dimensional space. This was a
significant advancement over previous research.
Considering that the gravitational field itself is an acceleration, Chae
argues, "From the beginning it seemed evident to me that gravity could be
evaluated most directly and effectively by computing accelerations. I came
up with this concept after my recent study with galactic rotation curves.
Galactic disks and wide binaries have certain similarities in their orbits,
however hydrogen gas particles in a galactic disk have approximately
circular orbits whereas wide binaries have very elongated orbits.
Chae also measured the frequency of concealed nested inner binaries at a
benchmark acceleration, which is different from prior research.
According to the study, general relativity and Newton's universal law of
gravity both predict that an orbit between two stars will vary from one
another when the accelerations are less than one millimeter per second
squared.
The measured acceleration is around 30 to 40% greater than the
Newton-Einstein prediction for accelerations less than 0.1 nanometer per
second squared. The significance is quite high and satisfies the traditional
standard for a scientific discovery, 5 sigma. Two separate acceleration bins
in a sample of 20,000 broad binaries with a distance limit of 650 LY each
exhibit variances with > 5 sigma significance in the same
direction.
The reported rise of accelerations at lower accelerations is a puzzle
because the measured accelerations higher than around 10 nanometer per
second squared correspond well with the Newton-Einstein prediction from the
same research. Intriguingly, this breakdown of the Newton-Einstein theory at
accelerations weaker than approximately one nanometer per second squared was
proposed 40 years ago by theoretical physicist Mordehai Milgrom at the
Weizmann Institute in Israel in a new theoretical framework known as
modified Newtonian dynamics (MOND) or Milgromian dynamics in current
usage.
Additionally, the Milgrom and the late physicist Jacob Bekenstein's AQUAL
MOND-type Lagrangian theory of gravity accurately predicts the boost factor
of roughly 1.4. It is interesting that the right boost factor necessitates
the Milky Way galaxy's external field effect, which is a singular prediction
of MOND-type modified gravity. As a result, the vast binary data reveal both
the breakdown of Newtonian dynamics and the appearance of modified gravity's
external field impact.
In response to the findings, Chae asserts that "it appears improbable that
a conspiracy or unidentified systematic might induce this
acceleration-dependent breakdown of the standard gravity in conformity with
AQUAL. I have investigated every potential systematic as outlined in the
lengthy text. The outcomes are accurate. I predict that future research will
use better and more comprehensive data to validate and improve the findings.
For the sake of transparency and to assist any interested scholars, I have
also made all of my codes available.
Wide binary dynamics cannot be influenced by dark matter, even if it
existed, unlike galaxy rotation curves where the observed enhanced
accelerations may, in theory, be attributed to it under the Newton-Einstein
standard gravity. According to the MOND framework, the weak acceleration
limit is where the conventional gravity just fails.
Wide binary dynamics has important ramifications for cosmology, theoretical
physics, and astrophysics. Einstein's general relativity was finally
inspired by anomalies in Mercury's orbits that were discovered in the
nineteenth century.
A new theory that extends general relativity to the low acceleration MOND
limit is now necessary to explain abnormalities in broad binaries. Despite
all of Newton's gravity's triumphs, general relativity is required to
explain relativistic gravitational phenomena like gravitational waves and
black holes. Similarly, despite all of general relativity's achievements, a
new theory is required to explain MOND events in the weak acceleration
limit. The ultraviolet disaster of classical electrodynamics, which gave
rise to quantum physics, may share some similarities with the
weak-acceleration catastrophe of gravity.
Wide binary anomalies are a catastrophe for conventional gravity and
cosmology, which rely on the ideas of dark matter and dark energy. There is
no longer a requirement for a significant amount of dark matter in galaxies
or even the cosmos because gravity follows MOND. Chae, who, like most
scientists, "believed in" dark matter up until a few years ago, is likewise
quite surprised by this.
A new physics revolution appears to be underway right now. According to
Milgrom, Chae's discovery is the product of an intricate study of
cutting-edge data that, in my opinion, was carried out extremely
painstakingly and thoroughly. However, we need independent investigations to
corroborate such a broad finding—which is in fact quite broad—preferably
with better future data.
"This anomaly will have enormous implications for astrophysics, cosmology,
and for fundamental physics at large if it is confirmed as a breakdown of
Newtonian dynamics, and especially if it indeed agrees with the most
straightforward predictions of MOND."
It is exciting that the departure from Newtonian gravity that my group has
claimed for some time has now been independently confirmed, and impressive
that this departure has for the first time been correctly identified as
accurately corresponding to a detailed MOND model, according to Xavier
Hernandez, professor at UNAM in Mexico who first proposed wide binary tests
of gravity ten years ago. The Gaia satellite's unparalleled precision, the
sizeable and carefully chosen sample that Chae utilizes, and his thorough
analysis make his findings sufficiently reliable to be considered a
discovery.
Professor Pavel Kroupa, who teaches at both Charles University in Prague
and the University of Bonn, has reached the same findings about the law of
gravity. The findings now strongly suggest that gravity is Milgromian rather
than Newtonian, he claims, citing both this test on broad binaries and our
experiments on open star clusters close to the sun. There are significant
ramifications for all of astrophysics.
