-2
$\begingroup$

Gravity makes things that are more dense fall. If we extrapolate this fact through the entire Universe, we can imagine Ordinary Matter falling more than Dark Matter, and Dark Matter falling more than Dark Energy.

From this perspective, can we think of Gravity as emanating from the repulsive “push” of Dark Energy, rather than an attractive “pull” from Matter?

$\endgroup$
  • $\begingroup$ "More massive objects would absorb more of that push, causing nearby objects to feel less push in that direction. This imbalance of push would lead to a net force towards a system’s center of mass." Please explain this $\endgroup$ – Matt Oct 9 '15 at 13:06
  • $\begingroup$ @MattS Let me reword it using our Solar System as an example: The more massive Sun absorbs / 'blocks' some of Dark Energy's expanding force from 'pushing' against less massive Planets. Because Planets are being pushed less from only 1 direction (the direction of the Sun), they will fall towards it. Of course, Planets also block some of Dark Energy's expanding force from pushing against the Sun, but the lesser mass of the Planets means they block much less force. Even so, the force Planets do block will cause the Sun (along with the Planets) to fall towards the Solar System's center of mass. $\endgroup$ – Asim Deyaf Oct 9 '15 at 14:53
  • 1
    $\begingroup$ Don't forget that Gravity affects everything, not only matter. You should explain for example how Dark energy causes light to bend near massive objects (which has been experimentally confirmed), if your conjecture was to be true ;) $\endgroup$ – Newbie Oct 9 '15 at 17:16
  • 3
    $\begingroup$ You should, instead edit this question to have the new text. Reposting is strongly discouraged, and edited questions get bumped to the top of the active queue. $\endgroup$ – dmckee --- ex-moderator kitten Oct 25 '15 at 19:18
  • 2
    $\begingroup$ Some older, related questions: physics.stackexchange.com/q/91120 physics.stackexchange.com/q/26692 $\endgroup$ – dmckee --- ex-moderator kitten Oct 25 '15 at 19:19
3
$\begingroup$

This is referred to as the Le Sage theory of gravity and is generally discredited because of a whole slew of problems with the concept, most notably drag

$\endgroup$
  • $\begingroup$ Yes, this is similar to Le Sage's Theory, except replace "Ultramundane Corpuscles" with Dark Energy. Regarding the drag problem, here's an excerpt from Wikipedia: "According to Le Sage's theory, an isolated body is subjected to drag if it is in motion relative to the unique isotropic frame of the ultramundane flux." Can Matter move relative to Dark Energy for drag to even be a factor? $\endgroup$ – Asim Deyaf Oct 25 '15 at 20:52
  • $\begingroup$ Here's an interesting excerpt from the "Coupling to Energy" section: "... any successful theory of gravitation must be nonlinear and self-coupling. Le Sage's theory does not predict any of these aforementioned effects, nor do any of the known variants of Le Sage's theory." If I'm not mistaken, Dark Energy is both nonlinear and self-coupling. Does this address the issue with Le Sage's Theory mentioned in the excerpt? $\endgroup$ – Asim Deyaf Oct 25 '15 at 22:26
  • $\begingroup$ Btw, I don't mean to sound like I'm pushing a theory here. On the contrary, I'm trying to understand the reason it's wrong so I can stop thinking about it. If any part of what I say is wrong or unclear, please don't hesitate to let me know. $\endgroup$ – Asim Deyaf Oct 25 '15 at 23:08
  • 1
    $\begingroup$ The bottom line is that nobody has discovered any "thing" that would make this theory of gravity work. The properties required are self contradictory. $\endgroup$ – user56903 Oct 26 '15 at 8:05
1
$\begingroup$

This can't be the sole answer to the problem of gravity, because a model like this would make modeling the solar system difficult -- if you eliminate the gravitational force from ordinary matter and replace it with a repulsive force from dark matter, where do you put the dark matter so that every planet and asteroid in the solar system obeys a $GM/r^2$ force law? We know that the answer can't be "in a shell at some great radius" due to Gauss's law, which also tells us that the answer can't be "distributed uniformly through the solar system", because this would give a different effective mass for Jupiter than it would for the Earth.

So, you still need ordinary gravity to explain the solar system. So, then we'd be using this repulsive dark matter to explain the stuff that ordinary dark matter does, but why would we posit an exotic gravitational force for something that we can already explain with ordinary dark matter obeying an ordinary gravitational force?

$\endgroup$
-3
$\begingroup$

Of course it could, that much is clear. The typical response from cosmologists is to introduce fudge factors such as dark matter, dark energy etc instead of acknowledging that relativity has been discredited. Realtivity is unfalsifiable because problems are explained away with the aforementioned fudge factors. Dark matter explains the drag and other problems observed at a large scale.

$\endgroup$
  • 2
    $\begingroup$ The problem is that most modified gravity schemes are much more complex than general relativity, and most of them STILL need dark matter and/or energy. TeVeS has a free undetermined function in its Lagrangian! $\endgroup$ – Jerry Schirmer Jan 31 '18 at 19:06

Not the answer you're looking for? Browse other questions tagged or ask your own question.