Korean scientists have developed a new method for determining the parameters of the motion of bodies in wide binary systems, which is based on an extremely accurate determination of their radial velocities. It can confirm the correctness of modified Newtonian dynamics, an alternative theory of gravity that is still considered marginal.
Wide binary systems
It’s quite possible that dark matter really doesn’t exist. At least, this rather unobvious at first glance conclusion can be drawn from a recently published paper by Korean scientists. In general, it reviewed the results of a new technique for investigating wide binary systems, but it has rather unexpected consequences.
Wide binary systems consist of two luminaries separated by several tens or even hundreds of astronomical units of space. All gravitational interaction means centripetal acceleration that a body receives. For the Earth’s surface, for example, it is 9.8 m/s2. For wide binary systems, however, this parameter can be 1 nm/s2.
At the same time, it is extremely difficult to determine the motion parameters of two celestial bodies and their motion vectors in a wide binary system, because we see them practically in a frozen state. However, a paper recently published in The Astrophysical Journal describes a method for determining these parameters from only one measurement.
However, for this purpose, it is also necessary to know the radial velocity of the stars with high accuracy. And that’s an opportunity scientists now have thanks to the third release of data from the Gaia telescope. Their accuracy is still a bit lacking, but close to what the researchers need for their calculations and they have taken advantage of it.
Modified Newtonian dynamics
All this complicated stuff is done for one purpose: to calculate how many nanometers per second squared the acceleration is actually there for the components of binary systems. This is very important in view of the fact that it is suspected that this number will turn out to be different from what the classical formula of Newtonian celestial mechanics suggests.
Indeed, the new technique shows with a high confidence of 4.2δ that this acceleration is 40-50% larger than predicted by classical theory. And this is exactly as much as it should be according to its alternative — modified Newtonian dynamics.
Regarding how much we can trust the results obtained, scientists will figure out thanks to the following studies. But the Modified Newtonian Dynamics is worth mentioning separately. It was developed about 40 years ago, but until now it remains a marginal theory, that is, most physicists do not reject it directly, but do not recognize it either.
The point is that it is more complicated than the traditional formulas for gravitation, but the difference with them provides a small one. Predominantly it would have to be visible on large scales. Indeed, the discrepancy in the rotation of stars in galaxies is well explained by it.
However, the modified Newtonian dynamics still needs to be tested on smaller scales. And there are problems with that, because it would require too much precision. Not to mention that some prevailing theories will have to be heavily revised.
After all, if we calculate the gravitational influence by modified Newtonian dynamics, dark matter turns out to be unnecessary. What the world around us is like can be explained without it.
According to phys.org
