I've been receiving a lot of
email in the last week or two from people interested in the
idea that our universe is really a hologram. In my book and
this blog I've talked before about the connection between
the way of visualizing reality I'm proposing here and the
idea of the Holographic
Universe, a
connection that has also been noted in a few of the reviews
of my book. Now, here's
a link to
a recent story in New Scientist magazine that shows why
people's excitement about this idea has been re-ignited: the
article, written by Marcus Chown and published January 15
2009, is about new discoveries just announced by the GEO600 experiment.
GEO600 is a German project that has been looking for
gravitational waves for the past seven years. Here's some
excerpts from the article:

GEO600 has not detected any gravitational waves so far, but it might inadvertently have made the most important discovery in physics for half a century.

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.

If this doesn't blow your socks off, then Hogan, who has just been appointed director of Fermilab's Center for Particle Astrophysics, has an even bigger shock in store: "If the GEO600 result is what I suspect it is, then we are all living in a giant cosmic hologram."

The idea that our reality is
not continuous, but granular, broken down into planck-unit-sized
"grains" of spacetime is something I've been saying since I
launched my project. The idea, though, that proving the
existence of this granularity would be direct evidence that
our universe is a hologram is a not a connection I've talked
about before. This New Scientist article goes on to describe
the groundbreaking work in the 90's of such physicists as
Jacob Bekenstein, Leonard Susskind, Gerard 't Hooft, and
Juan Maldacena, some of which I've talked about in my book,
and in previous blogs like Why
Stop at Ten Dimensions, Hypercubes
and Plato's Cave,
and Why
Do We Need More Than 3 Dimensions?.
Here's a few more excerpts from the article:

What's more, work by several string theorists, most notably Juan Maldacena at the Institute for Advanced Study in Princeton, has confirmed that the idea is on the right track. He showed that the physics inside a hypothetical universe with five dimensions and shaped like a Pringle is the same as the physics taking place on the four-dimensional boundary.

According to Hogan, the holographic principle radically changes our picture of space-time. If GEO600 really has discovered holographic noise from quantum convulsions of space-time, then it presents a double-edged sword for gravitational wave researchers. One on hand, the noise will handicap their attempts to detect gravitational waves. On the other, it could represent an even more fundamental discovery.

More importantly, confirming the holographic principle would be a big help to researchers trying to unite quantum mechanics and Einstein's theory of gravity. Today the most popular approach to quantum gravity is string theory, which researchers hope could describe happenings in the universe at the most fundamental level. But it is not the only show in town. "Holographic space-time is used in certain approaches to quantising gravity that have a strong connection to string theory," says Cramer. "Consequently, some quantum gravity theories might be falsified and others reinforced."

Hogan agrees that if the holographic principle is confirmed, it rules out all approaches to quantum gravity that do not incorporate the holographic principle. Conversely, it would be a boost for those that do - including some derived from string theory and something called matrix theory. "Ultimately, we may have our first indication of how space-time emerges out of quantum theory." As serendipitous discoveries go, it's hard to get more ground-breaking than that.

Regular readers of this blog
will note the important idea that our universe actually
comes from the fifth dimension, another drum that I've been
beating from the outset, and which I've talked about in a
number of blogs, such as Time
is a Direction, The
Fifth Dimension Isn't Magic,
and Flatlanders
on a Line. Speaking
in terms of spatial
dimensions, this article's comment that we live in a
universe with five dimensions and shaped like a Pringle is
extremely important.

Is Our Universe Flat or
Curved?

In our four-dimensional universe, it appears that space-time
is essentially flat. If it were truly flat, then parallel
lines would never meet and our universe would have no
boundaries in any direction. NASA's WMAP
project has
returned results showing that the universe is flat within a
2% margin of error. What does this mean? It means that for
most intents and purposes our universe is truly flat. But in
the largest picture of all, I believe that the above two
ideas are going to be shown to be equivalent - our universe
is very close to flat, but there is still a very slight
curvature, and the 13.7 billion year "boundary" that
cosmology shows us as being our line of time back to the big
bang will still show that we are only witnessing a tiny
region of a much larger whole, an idea that is central to
this project and which we've talked about in recent entries
like Dreaming
of Electric Sheep and Imagining
the Omniverse. So,
in the same way that Euclidean geometry makes sense in our
local frame of reference--a square building really is
constructed from lines at 90 degree angles and parallel
lines don't ever meet--if we look at the entire planet we
can see that a square that encompasses a hemisphere must
have angles that are slightly larger than 90 degrees and
parallel lines really can meet each other as they traverse
the globe. That "pringles potato chip" shape they are
referring to, then, is like the horizon we see all around us
as we are in the middle of the ocean: all we need to do is
widen our frame of reference beyond the boundaries of 4D
space-time to see how that horizon is created by a very
subtle curvature that for any local observations is so small
as to be inconsequential, but in the biggest picture of all
it gives us a way to visualize how the holographic
information that defines our universe from the fifth
dimension is "just over the horizon" of our 4D spacetime.

You are a Hologram

The cover of this New Scientist issue we're quoting from
here sums it up this way - "YOU ARE A HOLOGRAM - projected
from the edge of the universe". While this phrase gives us
one way to think about the fifth dimension as coming from
the boundary of our 4D spacetime, I've talked many times
about other ways of visualizing how each additional
dimension is "around" or "outside" the previous one - so
rather than thinking about the hologram that creates our
universe as being something that is far far away, I think
it's more useful to think about the hologram as being "just
around the corner in time" - which is the phrase I use in my
song "The
Unseen Eye".

As we discussed in "What
Would a Linelander Really See",
the term "extra dimensions" is often used by physicists
rather than "higher dimensions" when talking about the
dimensions beyond spacetime: I think this is a useful
distinction, because saying "higher" somehow sets the idea
up in our minds that we should be gazing skyward as we think
about these additional dimensions. In blog entries like Unlikely
Events and Timelessness and Time
in 3 Dimensions,
we've talked about how "events that are so unlikely they
will talk longer than the life of the universe to occur" is
another useful way of visualizing how we can derive the
information that represents dimensions beyond 4D space-time,
another useful branch to this discussion.

Information Becomes Reality

Are we embedded in a fifth-dimensional hologram which is at
right angles to the fourth dimension? Imagining what the
phrase "at right angles to the fourth dimension" means has
been one of the main ideas behind this project. If you've
been following along, I hope that by now you have grown more
used to thinking about the fifth dimensional probability
space as it relates to Everett's Many Worlds Interpretation,
the universe as a hologram, and the digital
physics concept
that information
equals reality -
I believe these ideas will eventually be shown to all fit
together in the big picture of timelessness.