Change law of gravitation to remove dark energy and dark matter

In summary, there has been a discussion about the speed of stars in our solar system not matching the visible mass, and the proposal to change the law of gravitation F = 1/r^2 to fix this issue. This change would also involve including a repulsive force. However, there are concerns about whether this fix would violate other measurements, such as the detection of dark energy through the integrated Sachs-Wolfe effect. Some alternate gravity theories have been mentioned, but there is no clear consensus.
  • #1
Alain De Vos
36
1
The speed of star on the outer of are solar system is not according to the visible mass.
Change the law of gravitation F = 1/r^2 to fix this.
Galaxies far away are moving away with increasing speed.
Change the law of gravitation F = 1/r^2 to fix this, include a repulsive force to fix.
Would this fix violate other measurements , which ones ?
 
Space news on Phys.org
  • #2
Alain De Vos said:
Would this fix violate other measurements , which ones ?
Yes. If I understood it correctly, then dark energy can be measured by red and blue shifts of photons leaving / falling into the gravitational potentials in the CMB. That gravitation works as we think it does is proven by the visible matter and energy. The computer models with dark matter match the real world. However, I am not certain that this is a reliable description, my source was pop science.
 
  • #3
There are plenty of alternate gravity theories. I don't think any of them are completely satisfactory - they can explain some things but not others.
 
  • #4
Alain De Vos said:
The speed of star on the outer of are solar system is not according to the visible mass.
Change the law of gravitation F = 1/r^2 to fix this.
Galaxies far away are moving away with increasing speed.
Change the law of gravitation F = 1/r^2 to fix this, include a repulsive force to fix.
Would this fix violate other measurements , which ones ?
See, for example:

https://en.wikipedia.org/wiki/Modified_Newtonian_dynamics
 
  • Like
Likes Ibix
  • #5
fresh_42 said:
Yes. If I understood it correctly, then dark energy can be measured by red and blue shifts of photons leaving / falling into the gravitational potentials in the CMB.
I think you are thinking of the integrated Sachs-Wolfe effect, which is a result of dark energy modifying the gravitational potential wells of galaxy clusters, causing a change in the redshift of CMB photons as they pass through. This is not the same as the Sachs-Wolfe effect, which is derived from properties of the CMB alone.
 
  • #6
Alain De Vos said:
The speed of star on the outer of are solar system is not according to the visible mass.

What are you referring to here? Do you mean galaxy rotation curves? Our solar system is not a galaxy.
 
  • #7
Alain De Vos said:
Change the law of gravitation F = 1/r^2 to fix this.

What proposed model are you referring to? Can you give a reference?
 
  • #8
Didn’t they find some galaxies with no dark matter that behaved just like existing theory would predict?
 
  • #9
BWV said:
Didn’t they find some galaxies with no dark matter that behaved just like existing theory would predict?
Yeah - but...
How do they detect whether galaxies have dark matter or not, except by how the stars behave?
 
  • #10
DaveC426913 said:
Yeah - but...
How do they detect whether galaxies have dark matter or not, except by how the stars behave?
right, but observations of several galaxies behaving as theory would predict without needing dark matter supports the existence of dark matter and puts the kibosh on (some,most,all?) alt gravity hypothesis
 
  • Like
Likes DaveC426913
  • #11
BWV said:
Didn’t they find some galaxies with no dark matter that behaved just like existing theory would predict?
From previous discussion on here I gather that some modified gravity theories can handle that. Something to do with long-range effects from nearby galaxies, or something - I don't know the details.
 
  • #12
Alain De Vos said:
Change the law of gravitation F = 1/r^2 to fix this.
How do you want to change the laws? If there are any physics laws, and they are laws, they aren't changable. I have also read that the others that these laws are hipotetical and have something wrong. If we are speaking about something not fixed, we are speaking about teories, not laws. I think that here there is a misundrstanding
 
  • #13
vincenzosassone said:
I think that here there is a misundrstanding
Both "laws" and "theories" are words for things we've invented. We don't generally regard either as being changed, but we certainly develop newer theories (nothing new tends to get called a law these days) which supersede them.
 
  • Like
Likes vincenzosassone, berkeman and fresh_42
  • #14
Ibix said:
There are plenty of alternate gravity theories.

And the OP has not said which one he is asking about, which means we have no valid basis for discussion.

Thread closed.
 

1. How would removing dark energy and dark matter affect the law of gravitation?

If dark energy and dark matter were removed from the equation, the law of gravitation would still remain the same. However, the effects of gravity on the universe would be different as dark energy and dark matter play a significant role in shaping the structure of the universe.

2. What evidence supports the existence of dark energy and dark matter?

There is strong evidence for the existence of dark energy and dark matter from various observations, including the rotation of galaxies, gravitational lensing, and the cosmic microwave background radiation. These observations suggest that there is more mass and energy in the universe than what we can directly observe.

3. How does the presence of dark energy and dark matter affect the expansion of the universe?

The presence of dark energy and dark matter has a significant impact on the expansion of the universe. Dark energy is believed to be responsible for the accelerating expansion of the universe, while dark matter helps to slow down this expansion by providing additional gravitational pull.

4. What would happen to our understanding of the universe if dark energy and dark matter were removed?

If dark energy and dark matter were removed, our current understanding of the universe would need to be revised. Many theories and models in astrophysics and cosmology rely on the existence of dark energy and dark matter to explain various phenomena, such as the large-scale structure of the universe and the rate of expansion.

5. Is it possible to remove dark energy and dark matter from the law of gravitation?

No, it is not possible to remove dark energy and dark matter from the law of gravitation. These concepts are integral parts of our current understanding of gravity and the universe. Removing them would require a complete overhaul of our current theories and models, which would also need to be supported by strong evidence.

Similar threads

B Dark Energy, Dark Matter and the Speed of Light
    • Cosmology
Replies
23
Views
1K
I More extended equilibrium configurations due to dark energy?
    • Cosmology
Replies
19
Views
786
B What is Dark Matter or Energy?
    • Cosmology
Replies
13
Views
2K
I Tidal effects of galaxies orbiting one another with dark energy?
    • Cosmology
Replies
2
Views
798
I Bullet Cluster explained without 'dark substances'
    • Cosmology
Replies
16
Views
1K
I Is dark energy pushing or is it a mirror concept of gravity?
    • Cosmology
Replies
31
Views
3K
I The Evolution of Galactic Scale Cosmic Voids
    • Cosmology
Replies
1
Views
322
B Does dark energy or cosmic inflation explain flatness?
    • Cosmology
2
Replies
37
Views
3K
A Is the CMBR interpretation for dark matter a fudge?
    • Cosmology
2
Replies
35
Views
2K
I Effect of Dark Matter on fast moving bodies
    • Cosmology
Replies
10
Views
1K

Hot Threads

Recent Insights

Back
Top