The Universe

Your 1st post and you dare ask such a simple question?

Welcome aboard! I can't wait to hear what the brainiacs come up with on this one.

My take is, predetermined by what?

If it has a predetermined size, what's on the other side of the wall?

These are the questions that drive good men mad.

Do we know the size of the universe?

No, we do not. We estimate the size of the observable universe (about 46 billion light years) but we do not have information beyond the objects whose light has reached us. Whether or not the universe "outside" of the part that we observe is finite or infinite has made for some rather entertaining dinner party conversation, but it is a question that has not been empirically settled.

No, we do not know the size of the universe. We never will.

"We" won't be around long enough. This planet won't exist long enough.

So, I think I'll have another drink.

Since not even light can bounce back from its "boundary", there is no point in asking the question, as the Universe is unmeasureable.

There is always a point in asking a question, whether its the reply you want is a different matter.

From the replies so far, as no one seems to know (or is unable to find out) the size of the universe, I think I am entitled to the assumption that the universe is a defined size and therefore is it possible that my theory is correct about the non-existance of Dark Matter etc.

The universe is not a defined size.

It might be a finite, undefined, size but an exact definition does not exist for this hypothetical size.

You are entitled to as many assumptions as you'd like to make.

Whoa there, you need to slow down a bit before declaring your ideas about physics and cosmology correct. (What you presented is not a scientific theory. It doesn't even classify as a hypothesis.)

Spend some time at BAUT, Physics Forums, and Science Forums. You will find numerous relevant discussions, often involving researchers actually studying and publishing papers on these subjects.

If the universe is a vehicle of predetermined size, whose make and model is unknown (because we're inside it and cannot stand back and admire the fins) then there is a still a way to answer the question.

All you have to do is find the glove box, and read the license and registration.

The currently receding galaxies are attached to each other by invisible strings. When these strings become taut, the expansion will stop. As you can imagine, the strings must be really, really, really strong. Hence the name "superstrings."

I don't know the size of the universe, but Paul Lutus's answer is that the universe is infinite; see for yourself here. He also proffers explanations of the theories involving dark matter, dark energy, and multiple universes, among others.

I have no affiliation with Mr. Lutus, nor cause to promote him, but thought you and other CR4'ers might find his website informative and interesting.