What if we are not real? What if everything we feel, everything we say, everything we see is nothing but a projection… something like a hologram? These questions may sound meaningless but the possibility of something like that cannot be ignored. At least this is what the Holographic Principle says.
Probably most of the western folks have not heard of this but there is saying popular in Hindu religion: “Sab Maya Hai”. That’s a Hindi phrase which in English literally translates into: “Everything is nothing but illusion”. The Holographic Principle adheres to that age old Hindu saying. According to Holographic Principle, our very existence which includes everything from our emotions to our inventions to our outer space explorations is nothing but a holographic projection of information saved somewhere far at the boundary of the space on a two dimensional (2D) surface.
You may end up asking: what is information? The question is simple but the answer is far more complex than what we think. Everything around us and even we, the human beings, are outcomes of information.
Let us for instance assume that you are holding your phone in your hand. The phone is made of something. That something is made of atoms and sub-atomic particles. Now, these atoms and sub-atomic particles like electrons and protons must be arranged in a specific fashion to make up the material that is used for manufacturing the phone. This arrangement is information. Hopefully, you get a hang of what information is.
One of the basic principles of Physics is that information is never lost completely and that it keeps lingering around somewhere in nature once an object is destroyed. Similarly, once a person or an animal dies, the information that made up that living being stays and lingers around.
So now, the most logical question you can ask is: “what is the relation between information and our universe being a hologram or better put, what is the relation between information and Holographic Principle?”
To answer this question, we need to take a look at black holes and their properties.
- Black hole is gigantic sucker that sucks in everything that enters the event horizon or boundary of the black hole.
- Black holes even suck in light.
- Anything that falls into a black hole eventually falls into singularity.
- Anything that falls into singularity is destroyed.
Now we have a problem. Physics says that information is never lost. Again, anything that falls into a black hole is destroyed. So, if the basic principle of Physics is correct, even though the a object is destroyed inside a black hole, it’s information has to stay back.
This wouldn’t have been a problem if a black hole itself was never destroyed. Stephen Hawking proved it that a black hole eventually evaporates out or simply, dies because a black hole also gives out energy in form of radiations (known as Hawking radiation).
So, if a black hole eventually dies and evaporates out, where does the information about the objects that were sucked in by the black hole goes? Information is never lost!
This is where Stephen Hawking was challenged by physicist Leonard Susskind. Scientists proposed that when objects fall into a black hole, the information about the objects are stamped or plastered on the event horizon of the black hole and then the object is destroyed. Here the noteworthy points are:
- Event horizon is the boundary of a black hole.
- Event horizon is 2D by nature.
- Information is plastered on the boundary of a space (here the space is black hole).
Whatever has been said so far did not answer the question: what is the relation between information and Holographic Principle?
In 1993, Nobel laureate Gerard ‘t Hooft and physicist Leonard Susskind from Standford together came up with a ground-breaking theory where they said that: “the amount of information present inside a space is related not to the entire volume of the space but the surface area of the boundary that encloses the space.”
According to the two learned men, in the boundary of the enclosed space, one piece of information can stay in every one square Planck length.
To make things more simple: Imagine a flat 2D area and divide it into smaller squares (a grid) of equal size. Something like what you see in the image below:
If we keep making the small squares smaller and smaller and further smaller, what is the smallest square we can get?
In Quantum Physics, the smallest distance possible between two points is 10-33. This is the Planck length. Assuming that a line is no longer than one Planck length, we can get a square with area of one square Planck length using four such lines.
Thus, in the above image, imagine that each small square you see is of actually one square Planck length in area. According to Hooft and Susskind, only one information can be stored in one square Planck length of area.
What is the big deal here?
Imagine a room full of people, air, a few indoor plants, a big TV set, a few laptops, tables and chairs etc. This room has a volume and the space has a boundary with a surface area. Inside the room is a set of people and objects that contain information.
According to Hooft and Susskind, all the information present inside the room (volume measurable only in 3 dimensions) is also present on the surface area (measurable in 2 dimensions).
Thus, every one piece of information in all the information present inside the room is present in one square Planck length on the surface of the boundary that encloses the room (or space that contains the information).
In essence, all the information in a 3D space is actually present on a 2D surface.
So, how does that answer the actual question? We haven’t yet answered it. To answer it, we need to look further back in time. In 1982, a physicist named Alain Aspect from University of Paris found that under certain conditions, sub-atomic particles (example, electrons) communicate with each other instantaneously irrespective of the distance between them. Whether the particles are separated by a distance of 10 feet or a humongous distance of 10 billion miles, they just happen to mirror each other instantaneously. That was puzzling because for that to happen, the communication had to take place at a speed greater than the speed of light and Einstein said that no communication can take place at a speed faster than light. This became popular as fallacy of Quantum Entanglement.
Several theories were put forward to explain the Quantum Entanglement fallacy but all of them were proved to be wrong. Then came David Bohm, a physicist from University of London who proposed that objective reality as we see is not present at all. Instead, he said that the world or the universe as we see is actually a very detailed hologram and everything that looks separate is just an illusion. In fact, Bohm said that everything is interconnected and the nature or the universe is nothing but one seamless web.
So, why did Bohm say that the universe was nothing but a hologram?
To understand this, we need to understand how hologram works.
A hologram is actually a detailed 3D image of an object and this hologram is created using lasers. First, an object is placed and is bathed in a laser beam. The laser beam then reflects light. A second laser beam is then bounced off the reflected light from the first laser beam. When this is done, an interference pattern is formed which is then captured on a film.
The developed film actually looks like a swirl of dark lines and lights. Nothing can be deciphered from the 2D surface of the film just by looking at it. However, when a third laser beam is used for illuminating the developed film, a detailed 3D image is created which is known as hologram.
Funny thing about a hologram is that not only is it highly detailed but if the hologram is dissected right from the middle, we don’t really end up getting two cut off parts of a single image. What we instead get is actually two separate but complete holograms. The only problem with these two separate holograms is that they are just smaller in size but they are incredibly detailed and complete as the actual object that was photographed.
So essentially, a hologram is a complete and highly detailed 3D image created out of undecipherable information present on a 2D film surface.
Imagine what happens if you alter the swirls of dark lines and lights on the 2D film surface? Simple, the hologram will change. Going deeper, change in information on the 2D surface will actually change the entire hologram (or 2 or more smaller holograms, if the main hologram is dissected) and this change will be instantaneous because the information on the 2D film surface is not different from the 3D image. They are, in reality, exactly the same. So, changing one will change the other(s) instantaneously.
Coming back to Quantum Entanglement fallacy, what really happens is that under right conditions, the information on a 2D surface changes and thereby produces an instantaneous change in the sub-atomic particles irrespective of the distance between the two.
Later in 1993 a formal explanation was provided by Gerard ‘t Hooft and Leonard Susskind (as explained earlier) using Quantum Physics. This is what became popular as the Holographic Principle.
Later, the principle was expanded and applied to the whole universe and it essentially stated that what we see as a 3D universe is actually a holographic projection of information present on a 2D surface somewhere far on the boundary of the space or the cosmological horizon.
This expansion of the Holographic Principle was derived from:
- Information is never lost.
- Information is preserved on a two dimensional plane of event horizon when an object falls into a black hole by crossing the event horizon.
In 1997 it was Juan Maldacena – a physicist from Argentina who applied the Holographic Principle and developed AdS/CFT correspondence (anti-de Sitter space/conformal field theory correspondence) by proving a relation between the 5D anti-de Sitter space and its 4D boundary, thereby providing a mathematical proof that Holographic Principle is correct. Later on, the principle has been validated several times using mathematical calculations.
So, to our utter horror, we may be nothing more than 3D holograms acting out the information stored on a separate and far simpler 2D universe somewhere on the cosmological horizon.
Remember that the Holographic Principle is only theoretical physics and currently, we don’t have the technology to test the theory using experimental physics.