Is the Universe very big?

[LewisM]

Originally Posted by blindman

Same family, isn't it?

Same family perhaps, but different person .

It's like saying that Flat Earthers have synapses and neurons - sure, they do, but they function like a dead persons.

[xelasnave]

Why would anyone expect a member of the royal family to go for a size appropriate box given they live in a huge palace.

And flat Earthers ...well if they were the only fools we have to include in a modern world that I could manage...but they are out there and we can see them ... its the quiet crazies that are the problem.
Alex

[baileys2611 (Simon Bailey)]

Originally Posted by LewisM

I think he's confusing the Queen with The Queen's Mother.

Queen died long ago when Freddie passed away.

[Kal (Andrew)]

Originally Posted by xelasnave

I sometimes sit and wonder about the Universe, not why its here or if it had a start, but just how big it must be...

I read the science and get a mind numbing number which tells me the observable Universe is approx 100 billion light years in diameter.

And although I am never really sure as to what science really says it seems to suggest the Universe may be infinite...

The Universe certainly goes on and past the 100 billion light year diameter maybe forever.

But how can a human mind comprehend such distances...for me I can only think of light speed or distance as going aroind the Earth in a rocket seven times in one second...of course that is impossible because we can not get near the speed of light and at seven times a second we far exceed escape velocity...
But that is my crude ruler that I use to get some idea...
So at that speed or velocity I try and imagine crossing the solar system and our gallaxy, then to M31...a mere two million years at around the Earth at seven times a second...the local group and on and on...even the observable universe seems beyond comprehension...and beyond to infinity...well I guess I ask...do others ever think about things like this and do you have a method to make it somehow managable and are you able to relate to something similar to my rocket orbiting the Earth and using it to grasp something of how big the universe may be.
Alex

Like you, I spend alot of time pondering these things

The thing to remember about space is that it is tied to time. You can't have time without space, you can't have space without time. So is time infinite? Well, we have a start point for our space and our time 13 odd billion years ago, so I would say no.

My personal belief is that there are multiple spacetimes. Whenever a star goes supernova and creates a black hole, it is creating a unique spacetime. Our universe that we sit in would also be within a larger universe created through some such event. I'm guessing that our universe is expanding as it is still "consuming" energy from the parent universe. Should the opposite happen, and we start decaying more energy into our parent universe, the universe will start contracting. This would explain why our universe has expanded at different rates of speed over time.

The cycle of energy would be infinite. Space and time within this cycle would come and go, and we are in just one bubble

[xelasnave]

I wonder about other species.
From simple to complex.
How they govern themselves...hobbies...wars...every thing.
Alex

[cannon_gray (Cannon Gray)]

Well, there are two answers to your question: "Really big" and "We can't actually know."

The first answer is regarding what we call the "observable universe." This is the part of the universe we can see and interact with, and it includes billions and billions of galaxies, each comprising billions and billions of stars, and many of those likely accompanied by some kind of planetary body or bodies.


The second answer is regarding whatever lies beyond the observable universe. Grossly simplified, our current understanding of physics suggests that information cannot travel faster than the speed of light. That means everything we can know about lies within two 4-dimensional cones, one pointing into the future and the other pointing into the past. This is called our light cone. We are pretty sure there is more universe beyond our light cone, but we literally cannot say with absolute certainty because that part is beyond what we can observe.
The universe is certainly huge, and it might be infinite, but we can't say for sure.

[xelasnave]

Originally Posted by cannon_gray

Well, there are two answers to your question: "Really big" and "We can't actually know."

The first answer is regarding what we call the "observable universe." This is the part of the universe we can see and interact with, and it includes billions and billions of galaxies, each comprising billions and billions of stars, and many of those likely accompanied by some kind of planetary body or bodies.


The second answer is regarding whatever lies beyond the observable universe. Grossly simplified, our current understanding of physics suggests that information cannot travel faster than the speed of light. That means everything we can know about lies within two 4-dimensional cones, one pointing into the future and the other pointing into the past. This is called our light cone. We are pretty sure there is more universe beyond our light cone, but we literally cannot say with absolute certainty because that part is beyond what we can observe.
The universe is certainly huge, and it might be infinite, but we can't say for sure.

Thank you for offering rather decent input on this matter.

Here is another question.

If we subscribe to The Big Bang Theory which seems to suggest that we are able to trace the evolution of the Universe from a hot dense state with the implication that at this point it was finite...my question..how can we entertain that the Universe could be infinite as clearly we can not double and double etc etc a finite Universe, no matter how large it may become from a doubling up process or any process that seeks to increase the size of something finite to something that is infinite? Can't be done.

I also wonder why folk insist that the Universe came from nothing and say " according to the Big Bang Theory the universe came from nothing when clearly the theory only ever mentions a universe that is very hot and very dense..certainly something as opposed to nothing...and given that reality why do folk consider that space and time started at a point when to say that is clearly an assumption that takes us way past the hot dense state outlined in the theory and which in any event can not be determined because the sums break down such that whatever is there is referred to as a singularity...which again is clearly a "something" and not nothing...why should we then say space and time began just a little before we can suggest by the theory? Nothing in the theory suggest the Universe came from nothing yet people just j7mp to that conclusion with no support and contrary to the theory. Does this not mean the Universe can only be eternal if we can not establish a point where it was nothing?
And ..how long is a piece of string?
Alex