The center of the infinite universe

AI Thread Summary
The discussion highlights the misconception that the sun is the center of the galaxy, clarifying that it is located far from the galactic center. The participants explore the concept of an infinite universe, asserting that if the universe is indeed infinite, it cannot have a defined center or peripheries. They emphasize the uncertainty surrounding the overall shape of the universe, noting that it could be flat or curved, but no definitive observations can confirm this. The observable universe is limited by a horizon due to its expansion, making it impossible to ascertain the universe's total size or shape. Ultimately, the conversation underscores the complexities of understanding the universe's structure and the implications of its potential infinitude.
AnthonyFB
Messages
3
Reaction score
0
I just recently discovered that the sun may be the center of the galaxy and what not, but if the universe is infinite, there is no center. furthermore, dealing with the outer limits of the universe, what is the shape of the universe? it can be a sphere? wouldn't this mean that the terms circle, square, etc., being used to describe the shape of the infinite universe are erroneous and rather outdated?
 
Space news on Phys.org
AnthonyFB said:
I just recently discovered that the sun may be the center of the galaxy and what not,
No, our sun is pretty far out to the side. This link has an image that gets you an idea of where our sun lies:
http://www.star.le.ac.uk/educ/ourgalaxy.html

(note: this is, of course, not an actual image of our galaxy, because we're in it! It's another galaxy that has similar structure to our own.)

AnthonyFB said:
furthermore, dealing with the outer limits of the universe, what is the shape of the universe?
We don't know what the overall shape of our universe is. There is a horizon that limits our vision, due to how our universe has expanded with time. Because of this horizon, the most we can say is that our universe is significantly larger than the part of it we can see. But we don't know what the overall shape is.
 
Last edited by a moderator:
We can safely say the universe is at least 13.7 bly in all directions from earth. We cannot deduce if it is larger [due to the horizon thing chalnoth noted]. It may curve back upon itself, or be utterly flat out to infinity. There is no known experiment [or observation] known to date capable of resolving that issue. We do, however, know the observable universe is temporally finite.
 
To determine center we need peripheries. An infinite universe by definition has no peripheries. Therefore it can have no center. Actually, it's even questionable that such a universe could even exist at all.
 
https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
Why was the Hubble constant assumed to be decreasing and slowing down (decelerating) the expansion rate of the Universe, while at the same time Dark Energy is presumably accelerating the expansion? And to thicken the plot. recent news from NASA indicates that the Hubble constant is now increasing. Can you clarify this enigma? Also., if the Hubble constant eventually decreases, why is there a lower limit to its value?

Similar threads

Back
Top