Continuity of space (split from Paradox)

[Area54]

59 minutes ago, Strange said:

As far as we know, space is continuous so you could not do this. 

Is this correct? I thought from a quantum perspective space was necessarily granular and that until we have a ToE, or reach some similar insight, the matter (Accidental pun) will not be resolved.

[1x0]

1 hour ago, Strange said:

As far as we know, space is continuous so you could not do this. 

We can measure space with our physical reality based objective scalings.

1 meter is one meter does not matter I measure it in thin air or in dense rocks. Then does this mean that I could measure one meter in a black hole too? 

I mean a black hole has a measurable real size where our scaling unit (meter) could be measured. I understand that this reality will be relative to all observers. But does the relativistic recognition of the observer and its assumptions to measure reality changes the measurable reality itself?  

Thought experiment: 

There are 1 million technologically advanced intelligence in our galactic neighborhoods with 100 - 10 million lightyears away.

They got the common task to measure earth´s exact size and weight as well as its future path in space-time. 

What would be the difference between the measurements of the intelligence 100 light years away and the one 10 million lightyears away? 

If I could collect all 1 million measurement results originating from their individual perception in different physical realities and measure what reality really is (we know the size, the weight and the path of the earth) then could we estimate/recognize the general relativity caused torsion of the original information? 

Why could I not measure the exact meter in a black hole when I know how its mass impacts the presentation of energy and matter (it is denser).

I can observe a black hole and assume its size.   

We perceive on earth that a black hole is a 100K km wide physical object but if we would be in it it would be like 100K lightyears. The differences between the perceptions and reality itself should not mean the absolute incapability of exact measurements and convertibility. 

Space and the perception of space have to be relative (e.g to our general physical understanding) so the subjectively set objective measurement and relative perception should not change the exact physical extent of the space pointed out and described with a numeric expression of one Unit subjectively determined but objectively measurable.  

Edited February 11, 2018 by 1x0

[Strange]

41 minutes ago, Area54 said:

Is this correct? I thought from a quantum perspective space was necessarily granular and that until we have a ToE, or reach some similar insight, the matter (Accidental pun) will not be resolved.

I don’t think quantum theory says that space is (or needs to be) quantised - quantum field theory is based on special relativity, in which space is continuous. 

[Area54]

14 minutes ago, Strange said:

I don’t think quantum theory says that space is (or needs to be) quantised - quantum field theory is based on special relativity, in which space is continuous. 

This sort of thing is well above my pay grade, but these items appear to contradict you, at least as far as the possibility of non-continuity.

https://phys.org/news/2016-04-universe-space-time-discrete.html#jC

"In quantum gravity, quantum mechanics and classical physics are at odds: scientists are still uncertain how to reconcile the quantum granularity of space-time with the theory of special relativity."

http://www.phys.lsu.edu/faculty/pullin/sciam.pdf

This popular piece by Lee Smolin is accompanied by the heading "We perceive space and time to be continuous, but if the amazing theory of loop quantum gravity is correct, they actually come in discrete pieces."

http://sci.esa.int/integral/48879-integral-challenges-physics-beyond-einstein/

"Einstein's General Theory of Relativity describes the properties of gravity and assumes that space is a smooth, continuous fabric. Yet quantum theory suggests that space should be grainy at the smallest scales, like sand on a beach. "

 

There appear to be dozens, perhaps hundreds, of such articles.  I don't wish to take this thread so far off-topic, but I'd like to get this straight in my own mind.

[Strange]

You right; It is widely assumed that space-time will be discrete but currently there is no evidence for that nor any clear idea of how to describe it mathematically. 

(Wanted to say that before but typing on phone too tedious!)

[Area54]

37 minutes ago, Strange said:

You right; It is widely assumed that space-time will be discrete but currently there is no evidence for that nor any clear idea of how to describe it mathematically. 

(Wanted to say that before but typing on phone too tedious!)

Thank you. I generally stay clear of physics, but I thought I had picked up that smattering of knowledge somewhere along the way.

[MigL]

While LQG may require quantization of space-time because it is background independent ( like GR ,the background is the field ), and L Smolin has been focusing his research on LQG, other routes to quantum gravity, such as SString or M-theory work on a fixed background ( or stage, if you will, like QM ), and as such, don't require quantization of 'the stage'.
And there are many more active areas of research for a quantum gravity theory.
Very little in the way of testable predictions, though..

@1X0
relativity refers to relativity of measurements, NOT perception.
 

[1x0]

9 hours ago, MigL said:

relativity refers to relativity of measurements, NOT perception.

the perception is relative to the result of the measurements, which ones do not seem to be detailed enough, that we could make such a conclusion that the universe is finite or infinite. 

Edited February 12, 2018 by 1x0

[Strange]

2 hours ago, 1x0 said:

the perception is relative to the result of the measurements, which ones do not seem to be detailed enough, that we could make such a conclusion that the universe is finite or infinite. 

It is nothing to do with “not detailed enough” or “relative perception” (whatever that means).

[swansont]

6 hours ago, 1x0 said:

the perception is relative to the result of the measurements, which ones do not seem to be detailed enough, that we could make such a conclusion that the universe is finite or infinite. 

!

Moderator Note

The discussion here is whether space is continuous or discrete, and is based on relativity and other physics, i.e. it is mainstream physics. Perception has nothing to do with it. This is not the place for you to make assertions or raise other issues.