Jean-Pierre Luminet ( astrophysicien à l’observatoire de Paris-Meudon, directeur de recherches au CNRS, auteur de L’Univers chiffonné ).

have u heard about his theory of "Crumpled Universe"

" A crumpled space is a multiconnexed space of finished volume, whose size is smaller than observed universe (apparent ray: approximately 15 billion LY). Crumpled spaces create a topological mirage which gears down the images of the sources of light."
translation from:
http://www.unesco.org/courier/2001_05/fr/doss14.htm

any comment ?

Another French article--here comes BabelFish again...this time I'll fix the holes I can.

This space which crumples us....

With the entire place flat and infinite, the universe could be folded up on itself and our perception deceived by geared down luminous rays. In this set of mirrors, how can one determine the form of universe?

Which is the form of the universe? The problem is more complicated than it seems. If the immediate space, that which surrounds us, is correctly described by the Euclidean geometry , the microscopic space (on very small scale) and the cosmological space (on a very large scale) differ from it deeply. Indeed, according to laws' of quantum mechanics, microscopic space is as chaotic and fluctuating as foam on the surface of the oceans. In the same way, cosmological space is curved.

???????? us by curved space? Modern cosmology is, to a great extent, resulting from the general theory of relativity formulated by Albert Einstein at the beginning of the 20th century. According to is its equations, is any space deformed? curved? by the distribution of the matter in its centre. This curve appears through one the most fundamental forces of the universe: gravity.

If we study the form of space on a sufficiently high scale (that is, with scales higher than 1025 meters), one knows that is curved overall by a quasi uniform distribution of the matter (galaxy cluster). Its curve is thus itself uniform, c?est-with-statement constant d?un not with l?autre of l?espace. Moreover, the universe has a total dynamics: it can theoretically be expanding or contraction. At present, the observations indicate qu?il is expanding. The models with constant space curve, resulting from the theory of relativity, were discovered by Alexandre Friedmann and George Lemaître in the years 1920. In the simplest model, a space of positive curve (known as of spherical type) dilates initially starting from the big-bang, reaches a maximum size, then contracts for ??????? in a big-crunch. It could be also that space is of null curve (known as of Euclidean type) or negative (of hyperbolic type, that is,-with-statement in saddle of horse). In these two cases, the universe is expanding perpetual but the rate expansion slows down in the course of time.

In fact, recent observations suggest that space is close Euclidean, that is,-with-statement flat and in conformity with our perception. But they indicate also qu?il is expanding accelerated. The "engine" of this expansion answers another law: the "cosmological constant", that can be interpreted as vacuum energy. There remains crucial questions to solve. Do we lay out, with relativistic cosmology, one satisfactory description of the form of space on a large scale? One could believe it at first sight, but it is nothing. Even the question of the finitude or infinitude of space is not clearly distinct. Indeed, if a spherical universe is inevitably finished, an Euclidean universe or of negative curve is, him, compatible with finished or infinite spaces. This stage, we need one new approach to progress: that of the topology, which treats certain invariant forms of spaces. Euclidean space is not so simple as it appears to be. A surface without curve, for example, is not necessarily the plan. It is enough to cut out a band in the plan and then to stick the ends to obtain a cylinder.

But it presents a fundamental difference with the plan: it is finished in a direction. This type of property concerns topology and not the curve. By cutting out the plan and by resticking it, we havenot changed his local form, its curve, but we changed radically his total form, its topology.

We perceive phantom images In a flat space or simply connected (in the vocabulary of topology), two unspecified points are joined by only one geodesic, while in a multiply connected space , an infinity of geodesics join two points (see diagram). This property confers on spaces multiconnexes an exceptional interest in cosmology. Indeed, the luminous rays follow the geodetic ones of space-time. When we observe a remote galaxy, we think of seeing a single specimen in a given direction and at a given distance. However, if space is multiply connected, that means that the luminous rays are geared down. Consequently, they create multiple images of the galaxy observed. As all our perception of space comes from the analysis of these trajectories, if we live in a space multiconnexe we are plunged in a vast optic illusion which reveals the universe to appear vaster than it is. Remote galaxies, that we believe original, are actually multiple images of only one galaxy.

A crumpled space is thus a multiply connected space of finished volume, whose size is smaller than the observed universe (apparent ray: approximately 15 billion light years). Crumpled spaces create a topological mirage which gears down the images of the sources of light. The astronomers know the gravitational mirages well: in the vicinity one massive body, located on the line of sight one more remote object, the curve of space gears down the ways of the luminous rays coming from [arrière-plan]. We thus perceive phantom images gathered in the direction of the intermediate body called "lens". This type of mirage is due to the local curve of space around the lens. In the case of the topological mirage, this is not a particular body which deforms space, it is space itself which plays the role of the lens. Consequently, the phantom images are distributed in all the directions and all the sections of the past. This total mirage would enable us to see the objects not only under all their possible orientations, but also with all the phases of their evolution.


A cooled vestige of the big-bang

If space is crumpled, it is in a subtle way and on a very large scale, if not we would have already identified phantom images of our own galaxy or other well-known structures. However, this n?est not the case. How, then, to detect the topology of the universe? Two methods of analysis statistical were developed recently. One, cosmic crystallography, tries to locate certain repetitions in the distribution of the remote objects. Does the other study the distribution of the fluctuations of temperature of the fossil radiation? a cooled vestige of the big-bang?, what would make it possible, if space is crumpled, to highlight particular correlations. The experimental projects of cosmic crystallography and detection of these correlations are in hand. For instance, the observations are not sufficient to draw the conclusions on the total topology of space. But the next years open attractive prospects: major surveys counting a very great ????? number of remote galaxies and quasars, and measurements of the fossil radiation, thanks to the satellites Map and Planck. We will be able to perhaps then allot a form to espace.

<font size=-1>[ This Message was edited by: Zathras on 2002-12-20 16:10 ]</font>

ACK! Actually this article was previously translated:

http://www.unesco.org/courier/2001_05/uk/doss14.htm

So feel free to ignore the above translation.

OK. I saw this guy live in a conference.
he sepent a big effort to simplify his theory, but still difficult.
I remember, he gave this illustration:

Astrophysician asked God: tell me what's astronomy ?
God: here, enter this dark room. u'll find a candle in the middle. light it.

at that time he saw a lot of stars everywhere.
BUT what he didn't know: God put complicated mirrors at walls, ground, top ...

ie. part of the stars we see in sky, may be just illusion (virtual stars).

That's an interesting analogy. What we need to do is to find two galaxies that are actually the same. But there are a number of problems with this.
1) If the light ray is coming from a different direction, the two images of the galaxy may be at different angles relative to us. ie, one image shows it face-on while the other shows it edge-on.
2) If the light rays are travelling through a different distance to get to us, we may be seeing the galaxy at a different age so it's form might be different.
We would in practice never be able to be sure we were seeing the same galaxy.
Perhaps it's like Heisenberg said, or at least implied by his principle, "The only thing we can be certain about is uncertainty."

More importantly, it's described as happening on the cosmological scale, but could that mean that space-time ruffles distort our image of what we see in our own galaxy?