Model describes universe with no big bang, no beginning, and no end.

[Mr. Pedantic]

Model describes universe with no big bang, no beginning, and no end

(PhysOrg.com) -- By suggesting that mass, time, and length can be converted into one another as the universe evolves, Wun-Yi Shu has proposed a new class of cosmological models that may fit observations of the universe better than the current big bang model. What this means specifically is that the new models might explain the increasing acceleration of the universe without relying on a cosmological constant such as dark energy, as well as solve or eliminate other cosmological dilemmas such as the flatness problem and the horizon problem.

Shu, an associate professor at National Tsing Hua University in Taiwan, explains in a study posted at arXiv.org that the new models emerge from a new perspective of some of the most basic entities: time, space, mass, and length. In his proposal, time and space can be converted into one another, with a varying speed of light as the conversion factor. Mass and length are also interchangeable, with the conversion factor depending on both a varying gravitational “constant” and a varying speed of light (G/c2). Basically, as the universe expands, time is converted into space, and mass is converted into length. As the universe contracts, the opposite occurs.

“We view the speed of light as simply a conversion factor between time and space in spacetime,” Shu writes. “It is simply one of the properties of the spacetime geometry. Since the universe is expanding, we speculate that the conversion factor somehow varies in accordance with the evolution of the universe, hence the speed of light varies with cosmic time.”

As Shu writes in his paper, the newly proposed models have four distinguishing features:

• The speed of light and the gravitational “constant” are not constant, but vary with the evolution of the universe.
• Time has no beginning and no end; i.e., there is neither a big bang nor a big crunch singularity.
• The spatial section of the universe is a 3-sphere [a higher-dimensional analogue of a sphere], ruling out the possibility of a flat or hyperboloid geometry.
• The universe experiences phases of both acceleration and deceleration.

He tested one of the models against current cosmological observations of Type Ia supernovae that have revealed that the universe appears to be expanding at an accelerating rate. He found that, because acceleration is an inherent part of his model, it fits the redshift data of the observed supernovae quite well. In contrast, the currently accepted big bang model does not fit the data, which has caused scientists to search for other explanations such as dark energy that theoretically makes up 75% of the mass-energy of the universe.

Shu’s models may also account for other problems faced by the standard big bang model. For instance, the flatness problem arises in the big bang model from the observation that a seemingly flat universe such as ours requires finely tuned initial conditions. But because the universe is a 3-sphere in Shu’s models, the flatness problem “disappears automatically.” Similarly, the horizon problem occurs in standard cosmology because it should not be possible for distant places in the universe to share the same physical properties (as they do), since it should require communication faster than the speed of light due to their great distances. However, Shu’s models solve this problem due to their lack of big bang origin and intrinsic acceleration.

“Essentially, this work is a novel theory about how the magnitudes of the three basic physical dimensions, mass, time, and length, are converted into each other, or equivalently, a novel theory about how the geometry of spacetime and the distribution of mass-energy interact,” Shu writes. “The theory resolves problems in cosmology, such as those of the big bang, dark energy, and flatness, in one fell stroke.”

Link to the article in question.

[Schofield]

I didn't even read that (I'm about to however), but I already tell myself that there was no "beginning", and that there will be no "end".

[D.Sporky!]

Fascinating. I'm not sure how to visual the "3-sphere"ness though..

[Showd0wN]

I have to say this isn't really "new". I've seen this passed about recently but models such as this have been around for a while. It will be interesting to see when it is tested against other observations (Type Ia SN is not an entirely conclusive test, and there are plenty of models out there that fix the flatness/acceleration/etc. problem).

For the 3sphere: first read: stereographic projection then look at: a nice picture....

[Flash525]

I'll admit I haven't read all of that, but if there was no beginning, nor an end, why is there a beginning and an end for us? - if the Universe is indeed infinite, shouldn't we be infinite also?

[Mr. Matt]

Originally Posted by Aerilon

I'll admit I haven't read all of that, but if there was no beginning, nor an end, why is there a beginning and an end for us? - if the Universe is indeed infinite, shouldn't we be infinite also?

The universe isn't a cabon-based lifeform, with degrading protein chains and neural functions.

The fact that we live and we die is an important aspect of Earth's ecosystem. If all animals were to live indefinitely it would be disastrous. A similar ecosystem, of sorts, exists in the universe at large in the form of stars.

[Mr. Pedantic]

For the 3sphere: first read: stereographic projection then look at: a nice picture...

So that picture is the projection of a 3-sphere onto a 3D universe?

I have to say this isn't really "new". I've seen this passed about recently but models such as this have been around for a while. It will be interesting to see when it is tested against other observations (Type Ia SN is not an entirely conclusive test, and there are plenty of models out there that fix the flatness/acceleration/etc. problem).

The article said the model predicted periods of acceleration and deceleration. What causes these periods? Is it a regular oscillation, or does it occur more spontaneously?

[Showd0wN]

Yes, it's (sort of) analogous to a shadow. (If you look at the stereographic projection of a 2-sphere you'll see what I mean).

What causes these periods? Is it a regular oscillation, or does it occur more spontaneously?

In "standard" cosmological theories these are caused by the evolution of various (non-)interaction scalar fields. However in this theory the "new" idea is having varying constants (i.e. the speed of light) which change how the evolution of the universe proceeds. I'll leave this post as a placeholder in case you want a more detailed explanation and don't believe delving into the nuance would derail the thread (just let me know)

[NiteStryker]

If there was no beginning, where did everything come from?

This just seems like a theory for people who cant think outside the box.

[Mr. Pedantic]

In "standard" cosmological theories these are caused by the evolution of various (non-)interaction scalar fields. However in this theory the "new" idea is having varying constants (i.e. the speed of light) which change how the evolution of the universe proceeds. I'll leave this post as a placeholder in case you want a more detailed explanation and don't believe delving into the nuance would derail the thread (just let me know)

Another question: why is the big bang model being used instead of this one? Does the Big Bang model still describe the universe more accurately or more completely than this one? I haven't read the proper paper fully (seeing as I don't understand most of it) but the article has nothing but good to say about this new model and nothing but criticism for the Big Bang theory.

In "standard" cosmological theories these are caused by the evolution of various (non-)interaction scalar fields.

What scalar fields are these? Like time, etc?