Google is your friend. You should learn how to use it.jjson775 said:
You asked by how much the will expand before it begins to collapse. It will never begin to collapse. Then you asked by what factor the universe will expand in the future, but you didn't specify when in the future. So the problem is unanswerable as stated.jjson775 said:
What version of the Friedmann equation are you working with here?jjson775 said:
The problem statement specifies a density greater than the critical density.phyzguy said:
He ALSO didn't specify how far away he is talking about, which matters since the expansion "factor", as I envision him to be thinking of it, depends on distance as well as how far into the future. I don' t think he understands the answer in post #3.phyzguy said:
Ah. I missed that point. Well then, does that make it a well posed problem?haruspex said:
I think we need to see the specific Friedmann equation under consideration.phyzguy said:
See the rules for homework:jjson775 said:
"escaping" from what ? Kinetic energy relative to what ?jjson775 said:
Yes and yesPeroK said:
In my textbook, a large section of the universe is modeled as a sphere. The critical density is derived from the Hubble parameter H and the universal gravitational constant G. See formula above. The derivation considers a galaxy of mass m moving away from the center of the sphere. The kinetic energy of the galaxy is then equated to the potential gravitational energy.phinds said:
Scientists have observed that the light from distant galaxies is shifted towards the red end of the spectrum, known as redshift. This indicates that the galaxies are moving away from us, and the further the galaxy is, the greater the redshift. This is evidence that the universe is expanding.
The current expansion rate of the universe is known as the Hubble constant and is estimated to be 73.3 kilometers per second per megaparsec. This means that for every megaparsec (3.26 million light years) of distance, galaxies are moving away from each other at a rate of 73.3 kilometers per second.
Based on current observations and theories, it is believed that the expansion of the universe will continue forever. This is because the expansion is driven by dark energy, a mysterious force that is causing the expansion to accelerate. As long as dark energy continues to exist, the expansion will continue.
The distance between galaxies is expected to increase by a factor of around 2-3 over the next few billion years. This means that a galaxy that is currently 1 megaparsec away will be around 2-3 megaparsecs away in the future. However, as the expansion rate is accelerating, it is difficult to predict how much the distance will increase in the distant future.
The expansion of the universe is happening on a much larger scale than our solar system, so the effects on our solar system are minimal. However, the expansion is causing galaxies to move further apart, which means that in the distant future, our galaxy may no longer be able to interact with other galaxies. This could potentially have an impact on the formation of new stars and the evolution of our galaxy.
