Will universe collapse?

[vitttorrio]

Hello! So i have a question: The universe is expanding, meaning objects not close to eachother are moving away (making more space). Gravitivity of objects like the sun, never disappear in the universe. But at some space their attraction is barely perceptible. So if some time, every galaxy is so much away from each other, nothing pulls eachother anymore (there are only objects standing around in space). Would that mean the universe had no stability anymore? So will the universe colapse at some point? I´m not very educated in physics yet, so could somebody correct this assumption?

Edited December 11, 2022 by vitttorrio
writing mistake

[Genady]

ChatGPT says:

[Mordred]

1 hour ago, vitttorrio said:

Hello! So i have a question: The universe is expanding, meaning objects not close to eachother are moving away (making more space). Gravitivity of objects like the sun, never disappear in the universe. But at some space their attraction is barely perceptible. So if some time, every galaxy is so much away from each other, nothing pulls eachother anymore (there are only objects standing around in space). Would that mean the universe had no stability anymore? So will the universe colapse at some point? I´m not very educated in physics yet, so could somebody correct this assumption?

We still don't know the fate of the universe. Collapse is one possibility however we could eventually get heat death instead due to expansion. Other scenarios is the big rip however that one isn't too likely.

If the cosmological constant aka dark energy stays constant then we're likely heading to heat death. However if at some point the cosmological constant does reduce then a collapse can occur.

I should note expansion isn't directly due to expansion per se but via the thermodynamic relations of the various particles residing in our universe. Photons and neutrinos as well as other relativistic particles (radiation) gas a different equation of state to matter.

https://en.m.wikipedia.org/wiki/Equation_of_state_(cosmology)

How those relations in the link above evolve over time is given by

[math]H_z=H_o\sqrt{\Omega_m(1+z)^3+\Omega_{rad}(1+z)^4+\Omega_{\Lambda}}[/math]

This equation is used to calculate the value of Hubbles parameter \[H_z\] at a given cosmological redshift compared to the value today \[H_0\] 

Edited December 11, 2022 by Mordred

[swansont]

1 hour ago, Genady said:

ChatGPT says:

!

Moderator Note

ChatGPT is not a scientific source and I think we’d provisionally consider this speculation since the credibility is not established

 

[Genady]

1 minute ago, swansont said:

!

Moderator Note

ChatGPT is not a scientific source and I think we’d provisionally consider this speculation since the credibility is not established

 

Fair enough.