A cosmologist suggests a novel way to uncover the nature of spacetime on the smallest scales.
Cosmologist Craig Hogan ... has become enamored of a noise he claims is generated by something even tinier — a minuscule graininess in the otherwise smooth structure of spacetime.
Call it Hogan’s noise. Many physicists are skeptical, but if his hunch about the existence of this subatomic clatter proves correct, it could have a mind-boggling implication: that the entire universe is nothing more than a giant hologram.
What’s more, it would mean that the structure of spacetime on subatomic scales might soon be revealed.
Really interesting! Cool find. And "Hogan's noise" is testable, too. I didn't get a feeling, though, if the proposed test will falsify the theory altogether, or just limit some free parameter in the theory.
Re: Science News: Hogan’s Noise
Posted: Fri Feb 26, 2010 9:06 pm
by bystander
The way I read it, the FermiLab experiment could falsify the entire theory. I'm not sure I understand how the GEO600 experiment relates (the noise detected may or may not be Hogan's noise )
Re: Science News: Hogan’s Noise
Posted: Fri Feb 26, 2010 10:15 pm
by neufer
http://www.sciencenews.org/view/feature/id/56605/title/Hogan%E2%80%99s_noise wrote:
<<In most models that try to apply quantum theory to spacetime, the universe is indeed grainy, Schutz notes. But that graininess is usually the same everywhere in the cosmos. In contrast, Hogan’s model suggests the graininess isn’t UNIFORM. It gets amplified the farther an observer resides from grains in a remote region of spacetime. That concept “would be a major revolution” in quantum gravity research, Schutz says.>>
The physics blogosphere is buzzing about a new paper by cosmologist Craig Hogan -- the subject of a long feature by Ron Cowen in Science News -- proposing that our universe is a hologram, made up of pixels of spacetime. The so-called holographic principle has been around since the 1990s: it basically holds that the 2D surface area enclosing a 3D volume of spacetime pretty much encodes all the information contained within that volume -- just like a standard hologram.
Re: ScienceNews: Hogan’s Noise
Posted: Fri Jun 25, 2010 9:28 am
by wonderboy
I want this in laymans terms, because I struggle to get my mind round it! I like to think I can understand most things, but this has totally stumped me
Paul.
Re: ScienceNews: Hogan’s Noise
Posted: Sat Jun 26, 2010 2:52 am
by Beyond
Might the "sound" be coming from energy? more specificly the conversion of energy to strings?
So just for the purpose of trying to get my head around this, and for others. I need to pose a few questions that may or may not relate to the above. Here goes:
Since 3d virtual reality came out I have often wondered about the possibility that my life, as a human being, the world, in fact the whole Universe works in the same way a computer program works for the VR computer games. Behind the scenes there are very complex computations going on that we can't understand totally or see. And what we see as people through our eyes are the pixels. This is mind blowing guys.
But in a pc game, when i pick up a item, that item is not real. its an optical allusion made to look like what i think it is, so when i pick up this real cup of tea off my table, is it not real? and is there a program that makes me think its a cup of tea?
To have a holographic Universe, Is it to complex to have come into being by accident?
Am I living in a physical virtual reality?
If so, Who and where is the programmer?
<<Researchers at Fermilab are building a “holometer” so they can disprove everything you thought you knew about the universe. More specifically, they are trying to either prove or disprove the somewhat mind-bending notion that the third dimension doesn’t exist at all, and that the 3-D universe we think we live in is nothing more than a hologram. To do so, they are building the most precise clock ever created.
The universe-as-hologram theory is predicated on the idea that spacetime is not perfectly smooth, but becomes discrete and pixelated as you zoom in further and further, like a low-res digital image. This idea isn’t novel; recent experiments in black-hole physics have offered evidence that this may be the case, and prominent physicists have proposed similar ideas. Under this theory, the universe actually exists in two dimensions and the third is an illusion produced by the intertwining of time and depth. But the false third dimension can’t be perceived as such, because nothing travels faster than light, so instruments can’t find its limits.
This is theoretical physics at its finest, drowning in complex mathematics but short on hard data. So Fermilab particle astrophysicist Craig Hogan and his team are building a “holometer” to magnify spacetime and see if it is indeed as noisy as the math suggests it might be at higher resolution. In Fermilab’s largest laser lab, Hogan and company are putting together what they call a “holographic interferometer,” which – like a classic interferometer – will split laser beams and measure the difference in frequencies between the two identical beams.
But unlike conventional interferometers, the holometer will measure for noise or interference in spacetime itself. It’s actually composed of two interferometers – built one atop the other – that produce data on the amount of interference or “holographic noise.” Since they are measuring the same volume of spacetime, they should show the same amount of correlated jitter in the fabric of the universe. It will produce the first direct experimental insight into the fundamental nature of space and time, and there’s no telling what researchers delving into that data might find out about the holographic nature of the universe.
So enjoy the third dimension while you still can. Construction on the first instrument is already underway, and Hogan thinks they will begin collecting data on the very nature of spacetime itself by next year.>>
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