Theoretical physics: The origins of space and time

Nature ^ | 8/28/13 | Zeeya Merali

[LibWhacker]

Many researchers believe that physics will not be complete until it can explain not just the behaviour of space and time, but where these entities come from.

“Imagine waking up one day and realizing that you actually live inside a computer game,” says Mark Van Raamsdonk, describing what sounds like a pitch for a science-fiction film. But for Van Raamsdonk, a physicist at the University of British Columbia in Vancouver, Canada, this scenario is a way to think about reality. If it is true, he says, “everything around us — the whole three-dimensional physical world — is an illusion born from information encoded elsewhere, on a two-dimensional chip”. That would make our Universe, with its three spatial dimensions, a kind of hologram, projected from a substrate that exists only in lower dimensions.

This 'holographic principle' is strange even by the usual standards of theoretical physics. But Van Raamsdonk is one of a small band of researchers who think that the usual ideas are not yet strange enough. If nothing else, they say, neither of the two great pillars of modern physics — general relativity, which describes gravity as a curvature of space and time, and quantum mechanics, which governs the atomic realm — gives any account for the existence of space and time. Neither does string theory, which describes elementary threads of energy.

Van Raamsdonk and his colleagues are convinced that physics will not be complete until it can explain how space and time emerge from something more fundamental — a project that will require concepts at least as audacious as holography. They argue that such a radical reconceptualization of reality is the only way to explain what happens when the infinitely dense 'singularity' at the core of a black hole distorts the fabric of space-time beyond all recognition, ...

[LibWhacker]

A little light reading for your afternoon coffee break, hehehehe... But there are some fascinating graphics and videos at the source link!

[GraceG]

The “rubber sheet” analogy of gravity is broken.

The space that and object displaces has to go elsewhere and it it is expressed as negative energy in a sphere some distance from the massive object.

[null and void]

Is there a FReeper cosmologist?

I have a way of explaining inflation without breaking the speed limit. I’d like to fly it by someone skilled in the art in private so I don’t embarrass my self in public with an obvious mistake...

[PoloSec]

In the beginning GOD...just keep reading from there.

[jodyel]

http://www.geraldschroeder.com/AgeUniverse.aspx

Or read some of this guy’s stuff. Excellent reads.

[dr_lew]

Reminds me of NON SERVIAM by Stanislav Lem, reprinted with commentary in THE MIND'S I by Douglas Hofstadter.

From the story:

There is something unworthy in informing personoids that we have created them in enclosures that only simulate infinity, that they are microscopic "psychocysts," capsulations in our world.

[blueunicorn6]

I’m pretty sure that the rest of you were put here for my entertainment.

[kevao]

so I don’t embarrass my self in public with an obvious mistake...

And rob us of the great enjoyment we could have at your expense? You're no fun.

[kabumpo]

I love Lem.

[Salgak]

It's quite complicated: it's a wibbly-wobbly, timey-wimey sort of thing. . .

[cripplecreek]

“Imagine waking up one day and realizing that you actually live inside a computer game,”

Well I think its high time my user hooks me up.

[LibWhacker]

Speaking of which... Lol, I read your Freeper homepage. Pretty entertaining, thx!

[no-to-illegals]

Love these types of threads. I consider time to not be relevant, therefore my conclusion is the universe is one dimensional.

[null and void]

There will be plenty of opportunities, don’t you worry about it.

[<1/1,000,000th%]

Don’t hold your breath waiting for this one to get sorted out.

It took 50 years just to find the Higgs boson. And almost as long to solve the solar neutrino problem.

[<1/1,000,000th%]

Great post! This is a nice summary.

[PoloSec]

I read the article you linked.

Simplicity is what I strive for...in a nutshell God created a mature man, to have dominion over a mature earth.

[John Valentine]

The thing about cosmology is that no one is really an expert. The biggest difference between a duffer and a PhD theoretical Physicist when it comes to cosmology is that the Physicist knows how to make his ideas sound sophisticated - he knows the language of his trade. But the ideas are only marginally more likely to be right.

[Figment]

Sounds like someone on acid rambling...

[Pontiac]

In 2006, Ashtekar and his colleagues reported7 a series of simulations that took advantage of that fact, using the loop quantum gravity version of Einstein's equations to run the clock backwards and visualize what happened before the Big Bang. The reversed cosmos contracted towards the Big Bang, as expected. But as it approached the fundamental size limit dictated by loop quantum gravity, a repulsive force kicked in and kept the singularity open, turning it into a tunnel to a cosmos that preceded our own.

This year, physicists Rodolfo Gambini at the Uruguayan University of the Republic in Montevideo and Jorge Pullin at Louisiana State University in Baton Rouge reported a similar simulation for a black hole. They found that an observer travelling deep into the heart of a black hole would encounter not a singularity, but a thin space-time tunnel leading to another part of space.

I found this fascinating. I have for years thought that the singularity before the Big Bang must have been very much like a Black Hole. This reinforces that theory.

In these two simulations both the singularity prior to the Big Bang and the singularity of a Black Hole become tunnels. It could simply be that both simulations have a common or different mathematical errors that lead to this tunnel effect but I find it intriguing.