:New Scientist: “Our world may be a giant hologram”

Here’s an article in New Scientist that poses a very challenging idea:

“For many months, the GEO600 team-members had been scratching their heads over inexplicable noise that is plaguing their giant detector. Then, out of the blue, a researcher approached them with an explanation. In fact, he had even predicted the noise before he knew they were detecting it. According to Craig Hogan, a physicist at the Fermilab particle physics lab in Batavia, Illinois, GEO600 has stumbled upon the fundamental limit of space-time – the point where space-time stops behaving like the smooth continuum Einstein described and instead dissolves into ‘grains’, just as a newspaper photograph dissolves into dots as you zoom in. ‘It looks like GEO600 is being buffeted by the microscopic quantum convulsions of space-time,’ says Hogan.”

(Fair enough. Finding the cause of anomalous “noise” was got Penzias and Wilson the Nobel Prize for discovering the Cosmic Background radiation.)

It’s not surprising that there’s a fundamental graininess to the space-time continuum. That’s pretty much the direct implication of the Plank Constant being non-zero.

What’s interesting here is by detecting the granularity, and getting a “scale” for it.

Add to this the application of the holographic principle as a tool for describing the fundamental working of the Universe:

The idea that we live in a hologram probably sounds absurd, but it is a natural extension of our best understanding of black holes, and something with a pretty firm theoretical footing. It has also been surprisingly helpful for physicists wrestling with theories of how the universe works at its most fundamental level.

The holograms you find on credit cards and banknotes are etched on two-dimensional plastic films. When light bounces off them, it recreates the appearance of a 3D image. In the 1990s physicists Leonard Susskind and Nobel prizewinner Gerard ‘t Hooft suggested that the same principle might apply to the universe as a whole. Our everyday experience might itself be a holographic projection of physical processes that take place on a distant, 2D surface.

This is actually useful when we talk about looking at quantum fluctuations on the “surface” of a black-hole event horizon.

Since, at least mathematically, we can treat the observable Universe as an expanding black-hole, it means that we can, in principle, apply the holographic idea to the “surface” of the expanding observable Universe…

So…

If space-time is a grainy hologram, then you can think of the universe as a sphere whose outer surface is papered in Planck length-sized squares, each containing one bit of information. The holographic principle says that the amount of information papering the outside must match the number of bits contained inside the volume of the universe.

Since the volume of the spherical universe is much bigger than its outer surface, how could this be true? Hogan realised that in order to have the same number of bits inside the universe as on the boundary, the world inside must be made up of grains bigger than the Planck length. “Or, to put it another way, a holographic universe is blurry,” says Hogan.

This is good news for anyone trying to probe the smallest unit of space-time. “Contrary to all expectations, it brings its microscopic quantum structure within reach of current experiments,” says Hogan. So while the Planck length is too small for experiments to detect, the holographic “projection” of that graininess could be much, much larger, at around 10-16 metres. “If you lived inside a hologram, you could tell by measuring the blurring,” he says.

So that’s why this particular experiment underway is so interesting. It holds out the promise of being able to detect the graininess that we should be able to see if we live in a giant “hologram”.

Which means that events that occur on the out-bounds of space-time have measurable consequences in the interior, though we don’t really understand how or what the consequences would be yet. At this point there’s just a recognition that a causal connection can be made.

Heh. The heavens do control our lives on earth… just not exactly the way Astrologers have imagined.

Read the full article here.

Author: Nicholas Knisely

Episcopal bishop, dad, astronomer, erstwhile dancer...

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