What IS space?

[damocles]

lindagarrette

 

The wikipedia reference is quite good. You should read it. Spacetime is a continuum. It is not quantized.

 

However you look at it, space has to be itself quantized for there to be any kind of VOLUME. There has to be discrete intervals between the "points, strings, bits," (curly fries?) of space/time for quantum mechanics to make any sense. Yet at the same time the "intervals" must all be in contiguous contact to form a smooth boundary to give space a shape through which energy(bosons and leptons) can "flow".

 

http://arxiv.org/pdf/gr-qc/0508121

 

QUOTING the Abstract....

 

[

Due to quantum fluctuations, spacetime is probably ``foamy'' on very small scales. We propose to detect this texture of spacetime foam by looking for core-halo structures in the images of distant galaxies. We find that the Very Large Telescope interferometer will be on the verge of being able to probe the fabric of spacetime when it reaches its design performance. Our method also allows us to use spacetime foam physics and physics of computation to infer the existence of dark energy/matter, independent of the evidence from recent cosmological observations.

 

I may be misunderstanding these gentlemen?

 

edit: Long unnecessary quote deleted. Link was enough.

 

I don't believe that I misunderstand them.

[sergey500]

It ok people i got my answer, at the smallest scale, between particles there is uniform energy, that all. So it not nothing. First i was going for theory that there is particle that malees it self up and build the unioverse on, but that compleltly wrong. OK now i got answer

Thanks for your help...........unllees my theory makes no sense then TELLLLL MEEEE!!!!!!

[WebFeet]

It ok people i got my answer, at the smallest scale, between particles there is uniform energy, that all. So it not nothing. First i was going for theory that there is particle that malees it self up and build the unioverse on, but that compleltly wrong. OK now i got answer

Thanks for your help...........unllees my theory makes no sense then TELLLLL MEEEE!!!!!!

 

At the smallest scale we can measure, we have massless photons, which taking them as a particle rather than a wave , implies that at the smallest scale we have a medium which consists of particles and has between those particles, more particles. After all a photon is just unsigned energy.

 

This would tend to imply a medium consisting of particles, used to build everything in the Universe.

[nkt]

Why do you think a photon needs something to travel through? If you think of a ball or a bullet, they move rather better without anything in the way, so why should a photon require a medium?

 

Space is probably quantised, if you get down small enough. Everything has to be, really. A continuous analogue slider is limited by the granularity of the atoms and the tunneling effects in the materials, and so is only capable of being set to discrete levels. It is just that they are so close as to blur into one range at almost any resolution.

[WebFeet]

Why do you think a photon needs something to travel through? If you think of a ball or a bullet, they move rather better without anything in the way, so why should a photon require a medium?

 

The medium that a photon travels through enables distance to be defined.

 

IMO, a photon travels at inifinite velocity, except where it encounters other photons.

 

Photons are their own medium.

A bit like a drop of water in a pond. The environment of the pond determines how the drop of water reacts, but at the same time the drop of water is an integral part of that environment.

 

One of Maxwell's equations relates the speed of light to the permittivity and permeability of free space. The speed of light is determined by how much energy is contained in a section of free space and the rate at which that section will allow energy through.

 

If a photon is energy, then this could be interpretted as the speed of a photon is determined by the rate at which a section of free space will allow a photon to pass through it, which is in turn determined by how photons that section of free space contains.

 

The more photons you add, you less permeable and subsequently slower a photon can travel.

[infamous]

Let's preform a little thought experiment; Before the Big Bang, there existed a nothingness which nothing could exist within. As the great energy of the Big Bang was released, it created an energy matrix within which matter could exist. As this "energy bubble" expanded and cooled our present universe took on it's present character. At a point very distant in the future our universe will cool to the ultimate measure and Entropy will have reached it's limit. This raises a question in my mind; When this limit is reached, will this "energy bubble universe" cease to exist collapsing back into nothingness?????

[virtualmeet]

To paraphrase Einstein, Space is the thing that keeps everything from happening in the same place... :hihi:

 

Cheers,

Buffy

Yes buffy, and also according to string theory, space is also a substract for strings, the indivisible part of energy: strings use "space" to "move" between hyperspace.

According to string theory, everything made frome energy can be described by a sets of strings...so I'm thinking that, perhaps, the only way to describe "space" is to say that is the "incountable" part of our universe, since eveything else can be "countable" according to string theory... Or, if you want, apace is the "incountable" part of our universe (also, nature seems always be made from two opposites parts).

In short terms :

Space = !Strings

According to this view, space is no longer an "entity" in itself, it's existance is tied to the existance of strings: No strings ==> No space !!

[WebFeet]

Space = !Strings

According to this view, space is no longer an "entity" in itself, it's existance is tied to the existance of strings: No strings ==> No space !!

 

I think the other way around works better.

 

!Space = Strings (?)

No Strings != No Space

[virtualmeet]

I think the other way around works better.

 

!Space = Strings (?)

No Strings != No Space

Oh yes, this is an opposite view to what I have said :hihi:

[WebFeet]

As this "energy bubble" expanded and cooled our present universe took on it's present character.

I've always had a problem with this.

 

How does energy cool ?

 

The only way that an energy bubble can cool, is by dissipating its heat (energy). Where does it get dissipated? Into the void surrounding the bubble, resulting in the bubble expanding.

So isn't it correct to say that expansion and cooling are one and the same thing ?

Basically, the density of the energy bubble/cloud kept reducing.

 

Here's my view on the whole creation thing.

 

In the beginning there was a single pythagorian point containing all the energy in the Universe. This pythagorian energy point had a single identity and subsequently had no dimensions. The concept of a pythagorian point is usually viewed as the smallest thing imaginable - basically a coordinate. However, if there is nothing else to measure it against, it can be huge, in fact it could be the size of the Universe.

The Big Bang doesn't have to come from something small. A single uniform energy particle the size of the Universe.

 

Somewhere within this particle, there is flaw in the uniformity. This sets up a difference in potential between one side of the particle and the other. The result is Particle Mitosis. The particle splits to become two energy particles with seperate identities.

This Mitosis will continue until all the particles are the same size and have ceased to move. At which point we are back to having a single identity for all the energy - and the whole process starts over again.

 

If the energy between us and a distant galaxy were going through this Particle Mitosis, then it would give the impression that the space between us was increasing exponentially, making it look as though the galaxy was accellerating away from us.

[Qfwfq]

Everything has to be, really.

:hihi:

 

Why in the universe does everything have to be quantized?

[lindagarrette]

Let's preform a little thought experiment; Before the Big Bang, there existed a nothingness which nothing could exist within. As the great energy of the Big Bang was released, it created an energy matrix within which matter could exist. As this "energy bubble" expanded and cooled our present universe took on it's present character. At a point very distant in the future our universe will cool to the ultimate measure and Entropy will have reached it's limit. This raises a question in my mind; When this limit is reached, will this "energy bubble universe" cease to exist collapsing back into nothingness?????

Yes. It's called "the big rip' theory.

[Iron4ever]

Yes. It's called "the big rip' theory.

 

Here is a big rip of my own from MSNBC that may explain this theory a little better.

 

The universe is expanding at an ever-increasing pace, and something unknown is vacuuming everything outward.

 

What would happen if the rate of acceleration increased?

 

The big rip theory states that a phenomenal pace would overwhelm the normal, trusted effects of gravity right down to the local level. Even the nuclear forces that bind things in the subatomic world will cease to be effective.

 

The expansion could become so fast that it literally rips apart all bound objects. It rips apart clusters of galaxies. It rips apart stars. It rips apart planets and solar systems. And it eventually rips apart all matter.

 

Driving the known acceleration of the universe’s expansion is a mysterious thing is called dark energy, thought of by scientists as anti-gravity working over large distances.

 

The Big Rip theory has dark energy’s prowess increasing with time, until it’s an out-of-control phantom energy. Think of our car accelerating an additional 10 mph every half mile, then every hundred yards, then every foot.

 

Before long, the bumpers are bound to fly off. Sooner or later, our hypothetical engine will come apart, regardless of how much we spend on motor oil.

 

There are many unknowns. It is not clear if the dark energy driving expansion is a force not currently described by physics, or if it is merely a different manifestation of gravity over huge distances. The repulsion could be a response to dark matter, unseen stuff that is known to comprise 23 percent of the universe, based on firm observations.

 

Dark matter has unknown properties, and it may be related to dark energy. Einstein considered that gravity might work repulsively, in a manner consistent with his theory of general relativity.

 

Dark energy, being quantified only recently, tends to be discussed as some strange new force, in addition to the four fundamental forces: gravity, electromagnetism, and the strong and weak nuclear forces that govern atoms. But the repulsion is possibly just the way gravity behaves in the presence of dark energy. In that sense, it is not a new force.

[damocles]

Damocles to various:

 

Quote:

Originally Posted by infamous

As this "energy bubble" expanded and cooled our present universe took on it's present character.

 

There is some truth embedded in this statement.

 

Origtinally posted by Webfoot.

 

I've always had a problem with this.

 

How does energy cool ?

 

The only way that an energy bubble can cool, is by dissipating its heat (energy). Where does it get dissipated? Into the void surrounding the bubble, resulting in the bubble expanding.

So isn't it correct to say that expansion and cooling are one and the same thing ?

Basically, the density of the energy bubble/cloud kept reducing.

 

Here's my view on the whole creation thing.

 

In the beginning there was a single pythagorian point containing all the energy in the Universe. This pythagorian energy point had a single identity and subsequently had no dimensions. The concept of a pythagorian point is usually viewed as the smallest thing imaginable - basically a coordinate. However, if there is nothing else to measure it against, it can be huge, in fact it could be the size of the Universe.

The Big Bang doesn't have to come from something small. A single uniform energy particle the size of the Universe.

 

Somewhere within this particle, there is flaw in the uniformity. This sets up a difference in potential between one side of the particle and the other. The result is Particle Mitosis. The particle splits to become two energy particles with seperate identities.

This Mitosis will continue until all the particles are the same size and have ceased to move. At which point we are back to having a single identity for all the energy - and the whole process starts over again.

 

If the energy between us and a distant galaxy were going through this Particle Mitosis, then it would give the impression that the space between us was increasing exponentially, making it look as though the galaxy was accellerating away from us.

 

There is some ongoing mathematical speculation on your description of the "cosmic egg" that suggests local exothermic discontinuity within the "particle" gave rise to Space when the binding forces differentiated and mass first appeared as a spatial property. I don't buy into this explanation yet. What little I understand about cosmology causes me to side with those who speculate that the eruption from flat space was "non-local".

 

Originally Posted by lindagarrette

Yes. It's called "the big rip' theory.

 

http://www.google.com/url?sa=U&start=1&q=http://www.space.com/scienceastronomy/big_rip_030306.html&e=10342

 

I await more observations to test the supposition. To be valid, the Cosmological Constant has to be a variable of increasing value synchronous in asymmetry with time's directional asymmetry(the actual spatial inflation). As inflation speeds up, the ticks between events should slow down(Increased size of distance between "intervals".) for the hypothesis to hold up.

 

 

Originally Posted by nkt

Everything has to be(edit; insert "quantized", D.), really.

 

That supposition is still subject to testable negation, but I tend to agree that our space/time is packaged in "quanta".

 

Qfwfq Quote:

Why in the universe does everything have to be quantized?

 

Gravitation and this new "dark inflator" if it smears homogeneically across volume may be the binding force exceptions that supports the above negation. I predict that bosons that correspond to the suspected "forces" will be detected, though, through observation by their predicted macro-effects upon space/time from upcoming interferometer experiments that cannot be explained by any other practical theorectical means. If there are associated force particles involved, then there will most assuredly be a quantized event(interval) connected with those particles linked with those binding forces. Such observations will likely re-inforce the "holographic model" of quantized space/time hypotheses.

 

Suggested reading;

 

http://scholar.google.com/url?sa=U&q=http://arxiv.org/pdf/gr-qc/0201022

 

http://scholar.google.com/url?sa=U&q=http://arxiv.org/pdf/gr-qc/0003090

 

http://scholar.google.com/url?sa=U&q=http://arxiv.org/pdf/gr-qc/0006061

 

http://scholar.google.com/url?sa=U&q=http://arxiv.org/pdf/gr-qc/0111068

[CraigD]

Why in the universe does everything have to be quantized?

Let me begin by qualifying that I’m expressing a belief, something for which there is considerable evidence, but far from any sort of formal proof. My primary reason for holding it is that I find it, in many ways, including intellectually and emotionally, satisfying.

 

I believe that the universe is both finite and countable. Put in more conventional terms, I subscribe to the Holographic Principle.

 

The ultimate implication of this principle is that the universe at any measurable point in its history must be representable by a single very large integer. Thus, physical continuity, in the ordinary mathematical sense, is prohibited. Quantization is the common term describing how physical quantities – space, mass, etc. – are mapped to this integer.

 

Everything must be quantized, therefore, to avoid the necessity of a mapping to a non-finite set.

 

Many more qualified people than I have written about the consequences of the principle, but these are the terms by which I apprehend it.

 

Given that I matriculated from college in Math, with much focus on topology, which can best be described as the study of continuity, and from High School with a concentration on Philosophy, much focused on Platonic Forms, it’s odd that I’d adopt this belief, but I have.

[C1ay]

IMO, there is space and there is matter. Space is what matter occupies.

[CraigD]

IMO, a photon travels at inifinite velocity, except where it encounters other photons.

How do you reconcile your opinion with the observations that

• the speed of light in a vacuum is a constant?
  
• it is experimentally possible to measure this speed using only a single photon?

This aside, if the speed of light depends on the interaction of photons, would you not expect for measurements of the speed of light to show a great deal of variation? For example, would there not be a measurable difference in the speed of light when measured in open air during the night, than when measured by the same apparatus during the day?

 

Your position certainly has a kind of formal beauty, but I can’t see how it’s supported by experimental evidence.