Holographic Universe? Are we living on a hologram? Or inside a black hole? Our perception is that we live in a three dimensional world. What if our three dimensions, can be equally represented on a two dimensional surface? Does this mean we live in a hologram? Or could we be inside a black hole?
To understand the idea of the holographic universe, we have to start with two things, a black hole, and Stephen Hawking. A black hole is an object with so much gravity that even light cannot escape it. Near a black hole, there is something called the event horizon, that is the point beyond which light is stuck, it cannot escape the gravity. Space itself is falling inside the blackhole at the speed of light. The event horizon of a black hole forms a sphere around the black hole. We don’t really know much what happens inside the black hole. Things falling in seen to leave our universe and end up elsewhere.
Stephen Hawking, in 1981, proposed that this event horizon may be breaking one of the fundamental rules of physics - conservation of information. He showed that things that fall into the black hole seemingly disappear from this universe forever, that information is destroyed. This is the information paradox.
How is information destroyed? You can burn a book. Doesn’t that destroy information? Not exactly, the information is still available in the universe. If we had the right quantum tools to recapture all the energy and matter from the burning process, we could theoretically put all the information back together again. Nothing is lost in terms of quantum mechanics.
Stephen Hawking was saying something different. This was so earth shattering to quantum physicists. Two physicists that were shocked by Hawkings paper were Gerard t’ Hooft and Leonard Suskind. They proposed a solution to the information paradox, and in 1997, Argentinian physicist Juan Maldecena, put it in very precise mathematical terms.
What they showed is that even though information is lost inside the black hole, a perfect copy of it remains on the surface of the event horizon. This perfect copy is something like a hologram. This is the holographic principle – this is a property of quantum theory which resolves the black hole information paradox.
How do scientists come up with crazy concepts like this? Usually, breakthrough theories are derived from prior work done by other scientists. In this case, the scientist was Israeli physicist Jacob Bekenstein. In 1972, Bekenstein derived an equation that showed the maximum amount of entropy that any volume of space can have.
Information theory shows that this equation also represents the total amount of quantum information that can be held in any volume of space. Notice that the equation does not include volume, only the surface area. Total entropy or information in any given volume is related to surface area of the volume, not the volume itself. That’s surprising.
This equation acted as inspiration for scientists like ‘t Hooft, Suskind and Maldecena, to find further truths about the universe.
For a black hole, the holographic principle states that the description of all the objects which will ever fall in is entirely contained in surface fluctuations of the event horizon. This is where the concept of a hologram comes from because that’s what a hologram is, a 2 dimensional representation of a 3 dimensional object.
How is this related out our universe being a hologram, because we don’t seemingly live inside a black hole? These scientists extrapolated this holographic principle mathematically to show that our entire three dimensional universe can also be perfectly represented on the 2D surface of the universe. We are mathematically a projection of the information smeared on the two dimensional horizon of the universe. This horizon surrounds the entire universe and is located infinitely far away, so we could never reach it.
Does this mean we are living inside a black hole? No, that’s not what they are saying. They are just saying that any 3 dimensional space can be represented by a 2 dimensional surface. And just like anything on the inside of a black hole is a projection of this 2 dimensional surface on the event horizon, we too are a projection of this 2 dimensional surface of the universe.
So, are we really on the inside of the sphere or are we on the surface of the sphere? What you should understand is that the idea of a 2D surface is a mathematical construct. And even though it is rock solid mathematically, it doesn’t necessarily make it the fundamental nature of reality.
#Holographicuniverse
#Arvinash
