...a belief that the observable world objectively exists and is rationally intelligible, explicable, governed by laws, predictable.

Well, that is certainly an old fashioned point-of-view.

I think you'd get considerable disagreement from the Experts.

 

Back to the topic:

https://www.sciencealert.com/at-1-3...-officially-the-biggest-thing-in-our-universe

 

Well, that is certainly an old fashioned point-of-view.

I think you'd get considerable disagreement from the Experts.

Show me a scientist who doesn't believe anything.

 

Science is defined as "the study of" and makes no assertion of proof, facts, truth...etc., that's what scientists do.

Hi,

While I agree with that, you would never guess that from the way most articles and even theories themselves are presented. It usually comes out as, "It's this way", or, "It's that way", or, "Scientists have discovered that...".
Maybe that's the only problem not science itself.

I guess I never realized that science is like archeology. In archeology the assigned dates for finds are not always correct and so later have to be corrected, sometimes by thousands of years maybe more. That could end up being a never-ending process as well.

I guess we are lucky the journey itself can be very interesting.

 

Show me a scientist who doesn't believe anything.

Everyone believes something. Even things that aren't so.

 

I'd rather focus on the scientific method, and leave the definition of the word "science" to philologists ...

I don't blame you, but then what exactly is the "scientific method".
Maybe we are getting too far off topic now though.

 

Back to the topic:

https://www.sciencealert.com/at-1-3...-officially-the-biggest-thing-in-our-universe

Hi,

See maybe it is wording like that that leads us to believe that that is the end of the story. "Officially" seems to add an air of complete and static knowledge. What happens if something bigger is found next.

 

What astonished me when I was young and reading about relativity, is that nobody back then (not even Einstein) said "spacetime is curved" that was never the way Einstein expressed it, all they said is the equations connecting space, time, energy, gravitation happen to be the same equations that describe curved 4D manifolds.

We have no idea really why that model fits, it's incredibly mysterious.

 

The modern definition is: whatever the Experts say.

What's an 'Expert' ?
It's someone who knows the most recent information about a topic. That sort of circles us back I think.

Maybe we should all just agree that the universe is BIG, period
It is pretty amazing how BIG it is even if we just accept the current definition as being completely accurate. How many Earth's can we fit in the Universe if we filled it up somehow with planets the size of Earth, assuming some moderate estimate of its size.

 

What happens if something bigger is found next?

It really is turtles all the way down.

 

What's an 'Expert' ?
It's someone who knows the most recent information about a topic. That sort of circles us back I think.

Maybe we should all just agree that the universe is BIG, period
It is pretty amazing how BIG it is even if we just accept the current definition as being completely accurate. How many Earth's can we fit in the Universe if we filled it up somehow with planets the size of Earth, assuming some moderate estimate of its size.

A very interesting theoretical physicist was the late John Barrow, this is a brief talk about cosmology and infinity:

 

How many Earth's can we fit in the Universe if we filled it up somehow with planets the size of Earth, assuming some moderate estimate of its size.

You couldn't.

1. Such a Universe would go unstable long before it was populated with Earths.

2. Space is a manifestation of matter (gravity). More matter would make more space.

 

You couldn't.

1. Such a Universe would go unstable long before it was populated with Earths.

2. Space is a manifestation of matter (gravity). More matter would make more space.

You certainly like to contradict. You like to use your imagination for contradiction more than agreement. You can't see the Forest for the Trees as they say. You can't see other points of view your're too busy looking for something to contradict. Have fun with that.
If you start with a Universe of a given volume, of course you can think of it as being filled with spheres. What the heck is wrong with that. Nothing.

 

It really is turtles all the way down.

Makes no sense.

 

You certainly like to contradict. You like to use your imagination for contradiction more than agreement. You can't see the Forest for the Trees as they say. You can't see other points of view your're too busy looking for something to contradict. Have fun with that.
If you start with a Universe of a given volume, of course you can think of it as being filled with spheres. What the heck is wrong with that. Nothing.

I truly don't know what you are upset about.

I answered your question about a relativistic universe in a thread strongly influenced by relativity theory in the best way I could using what little knowledge I have about relativity and its effect on the overall size of the Universe.

Your thought experiment -- how many Earths can fit in the Universe? -- is an interesting question. When you apply relativity (and quantum mechanics) to the question, the answer is the same as "How many licks does it take to get to the Tootsie Roll center of a Tootsie Pop?": "The world may never know."

Or, "Three."

 

Makes no sense.

It's a Steven Hawking thing.

"Most people, Hawking writes, would find this cosmology ridiculous, but if we take the turtles as symbols of more and more fundamental laws, the tower is not so absurd. There are two ways to view it. Either a single turtle is at the bottom, standing on nothing, or it’s turtles all the way down. Both views are held by leading physicists."

 

It's a Steven Hawking thing.

"Most people, Hawking writes, would find this cosmology ridiculous, but if we take the turtles as symbols of more and more fundamental laws, the tower is not so absurd. There are two ways to view it. Either a single turtle is at the bottom, standing on nothing, or it’s turtles all the way down. Both views are held by leading physicists."

Which, in my understanding, means "there's either a physical (and theoretical) infinite, or there isn't" ... my personal opinion is that we're living in a finite universe, defined by a finite number of fundamental laws ... and I simply don't believe in a so-called "multiverse" mainly because: 1.- It's just a mathematical quirk, and 2.- By definition, the other universes would be so completely isolated from each other as to be inaccessible, so it would be just the same as if they wouldn't exist.

 

...my personal opinion is that we're living in a finite universe...

And, yet, relative to us and our perceptions, the Universe has no observable end.

No matter how far you look, you can always look farther.

 

The universe is (if I recall) regarded roughly as a "sphere" but with a 3D surface not a 2D surface (leaving time aside for the time being) so it has no boundary in the sense the surface of a ball has no boundary Despite the absence of any boundary, a ball nevertheless has a finite surface area and by analogy "space" has a finite volume.

In principle, if we were to travel at the speed of light (well any speed really I suppose) we'd eventually return to our starting point, much as we would if we followed a geodesic path on the surface of a ball.

For all we know, one of the stars we can see in the remotest part of the sky, is our own sun!

 

...if we were to travel at the speed of light...

...the size of the Universe would compress to zero -- in the direction of travel.

Edit: and no matter how long or far you traveled, you would always be at your starting point.