I Star with quadrupole in a binary system violates Newton's 3rd Law?

AI Thread Summary
In a binary star system where one star has a non-zero quadrupole moment, the other star experiences both the standard gravitational force and an additional quadrupole force. This situation raises questions about Newton's third law, as it appears that only one star feels the quadrupole force, creating an imbalance. However, calculations show that both stars actually experience forces from each other's quadrupole moments, ensuring that Newton's third law is upheld. Each star's gravitational influence is accounted for by considering the total forces acting on them, which includes the effects of their respective quadrupole moments. Thus, the application of Newton's third law remains valid in this context.
andromeda123
Messages
2
Reaction score
0
TL;DR Summary
If in binary system, one of the two stars has a non-zero quadrupole moment, then the other star feels an additional force. On the other hand, the second star feel only the usual gravity.
Assume that, in a binary system, one (and only one) of the two stars has a non-zero quadrupole moment. Then the other star feels the usual gravity force $F_g$ plus an additional force $F_q$ coming from the quadrupole potential. On the other hand, the first star feels only the usual gravity force $-F_g$. Applying Newton's third principle, however, results in an imbalance between action and reaction on the two stars, since only one of them feels a quadrupole force. How is it possible?
 
Last edited:
Astronomy news on Phys.org
phinds said:
??? Your "reference" is a link to where you can post a new thread. It has nothing in it.
Sorry, there is no reference, I have just deleted the link
 
andromeda123 said:
there is no reference
As far as I can tell, you are asking us to explain why something is true, but that something isn't true to begin with.
 
Yeah, you can be sure Newton's third law supercedes your intuition. If you go to calculate the gravitational forces, you will take every point in one star and apply its force to every point in the other star. Since you do that for both the total forces, they always obey Newton's third law. So both stars will feel an additional quadrupole term, one because of what you have, its quadrupole moment produces additional gravity on the other star, and the other because its own quadrupole mass distribution receives an additional force from the other star.
 
TL;DR Summary: In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect alien signals, it will further expand the radius of the so-called silence (or rather, radio silence) of the Universe. Is there any sense in this or is blissful ignorance better? In 3 years, the Square Kilometre Array (SKA) telescope (or rather, a system of telescopes) should be put into operation. In case of failure to detect...
Thread 'Could gamma-ray bursts have an intragalactic origin?'
This is indirectly evidenced by a map of the distribution of gamma-ray bursts in the night sky, made in the form of an elongated globe. And also the weakening of gamma radiation by the disk and the center of the Milky Way, which leads to anisotropy in the possibilities of observing gamma-ray bursts. My line of reasoning is as follows: 1. Gamma radiation should be absorbed to some extent by dust and other components of the interstellar medium. As a result, with an extragalactic origin, fewer...
This thread is dedicated to the beauty and awesomeness of our Universe. If you feel like it, please share video clips and photos (or nice animations) of space and objects in space in this thread. Your posts, clips and photos may by all means include scientific information; that does not make it less beautiful to me (n.b. the posts must of course comply with the PF guidelines, i.e. regarding science, only mainstream science is allowed, fringe/pseudoscience is not allowed). n.b. I start this...
Back
Top