Is space made up of individual units?

[CosmicVoyager]

Greetings,

Is space made up of individual units like pixels on a computer screen?

And the amount of space in the universe is increasing?

If so, I'm curious how to calculate how often a new pixel comes into existence between any two existing pixels? Or if a new pixel comes into existence every certain number of pixels across, how often does that happen?

Thank

 

[Dmitry67]

In superstring theories, in fact, there is a minimum distance.
But it is incorrect to imagine it as pixels on a screen.

 

[Chalnoth]

Greetings,

Is space made up of individual units like pixels on a computer screen?

And the amount of space in the universe is increasing?

If so, I'm curious how to calculate how often a new pixel comes into existence between any two existing pixels? Or if a new pixel comes into existence every certain number of pixels across, how often does that happen?

Thank

If space-time is divided in some manner, it won't be divided in any sort of ordered fashion (if it were ordered, that would set a preferred rest frame, which would mean that relativity couldn't work). So the space-time points available for matter to occupy would have to be randomly distributed. And with a random distribution, there is no problem with new positions popping into or out of existence.

 

[CosmicVoyager]

If space-time is divided in some manner, it won't be divided in any sort of ordered fashion (if it were ordered, that would set a preferred rest frame, which would mean that relativity couldn't work). So the space-time points available for matter to occupy would have to be randomly distributed. And with a random distribution, there is no problem with new positions popping into or out of existence.

I have been thinking space was like a grid, and did not understand how saying space curves explained anything since no matter how you twist the grid everything still follows the grid lines. Curving space would not affect anything any more than a bending a flexible computer display would.

- So what is the structure of space? Are the units moving around like molecules in a liquid? What are the properties of space? What substance is it like?

- Does the creation of new space consume something else? Photons moving through expanding space lose energy, right? Is that energy being converted into space?

 

[Chalnoth]

I have been thinking space was like a grid, and did not understand how saying space curves explained anything since no matter how you twist the grid everything still follows the grid lines. Curving space would not affect anything any more than a bending a flexible computer display would.

This is insufficient. Basically, there are many geometries that cannot be represented by a grid without tearing or singularities. A simple example is a sphere: it is not possible to wrap a flat surface so that it covers an entire sphere without tearing or singularities. This is a pretty general rule. It is possible to write down grids that somewhat accurately describe space-time over a limited area, but for most geometries it isn't possible to write down a single grid that describes the entire space-time. This does indicate that the fundamental nature of space-time, whatever it is, cannot be a grid.

- So what is the structure of space? Are the units moving around like molecules in a liquid? What are the properties of space? What substance is it like?

Well, we don't know. This would require a theory of quantum gravity, which we don't have yet.

- Does the creation of new space consume something else? Photons moving through expanding space lose energy, right? Is that energy being converted into space?

Highly unlikely. It is more likely that the space-time points simply arise as a result of the amount of mass-energy nearby, similar to how photons simply appear out of the vacuum as a result of nearby electric charge.

 

[granpa]

curved space is possible with a grid
the layout of the grid can't change but the 'distance' between any 2 neighboring elements can change.

 

[Tanelorn]

For some reason I came away from my Physics class 30 years ago thinking that space and time were quantized. Something about the smallest possible distance being Plancks constant h. I hadnt questioned that until now.

 

[Chalnoth]

For some reason I came away from my Physics class 30 years ago thinking that space and time were quantized. Something about the smallest possible distance being Plancks constant h. I hadnt questioned that until now.

Yes, well, that is a general expectation of quantum gravity. It isn't, however, possible for space-time to be quantized in a regular way.