Yup, it’s time for another article. Just to let the internet know that I still exist. By the looks of the title, you may think that this article might just be about those cool stuff known as holograms. Well, I’m pretty sure that most of you don’t know about holograms but if you have seen some cool sci-fi movies or read some books, you probably have a vague idea about what a hologram is. They are those weird projector-like gadgets where we see the image of someone. In many films, we also see them communicating via holograms. Well, these may be science-’fiction’. But the principle of holography is a valid scientific principle and not just any fairytale.
In fact, that vague idea is very important so that I can discuss the principle of holography. And why am I suddenly doing that? First of all (as can be assumed from the title), our universe can possibly be a hologram. Before going further, I wanna assure the ones going through an existential crisis that there’s no reason to worry about. I am not saying that you’re non-existent, at least not in this theory. Let that be a talk for a later time. Secondly(and the more important reason), I had to write ‘something’. Then, without further ado, let’s hop into the next section!
The Principle Of a Hologram
When you go to the theaters to watch a film, you might have noticed a projector, projecting the image to the white screen where you see the movie. Here, the projector projects a 2D movie into a 2D screen. And hence, we see 2D characters moving on a 2D screen. But what is different in a hologram? The principle of holography is based on the interference of light. When you record a video, you store it in your camera/mobile phone. Afterwards, you play it and you can watch the video whenever you want.
A hologram works the same way. The wavefronts are recorded in the holographic device and later are re-constructed to be shown as holograms. The hologram is the final product. But it is still unclear why a hologram is so different from a video. That is because a hologram is a 3D projection of a 2D image. Just like in sci-fi movies, where you see an image in 3D space popping out from the projector of the gadget(Hopefully, that didn’t sound like a filmmaking article).
The Holographic Universe and Black Holes
In simple words, a hologram is a 3D projection of a 2D image. But, why is it still important? (Although ‘black holes’ are enough to make them important)Well, while fighting over the black hole information paradox(just google it), our scientists discovered that on the area of the event horizon of a black hole(2D surface), you could store enough information to describe any 3D objects inside it, just like a hologram.
In a CD, all the information is encoded in the disk. The information is then decoded so you can watch the video. The surface of the black hole works the same way. All the information necessary to define the 3D objects are encoded in the 2D surface. Also, the entropy of the black hole is proportional to the area of its event horizon. Usually in our daily lives, entropy is proportional to the volume of the object. But it seems that in the case of black holes, equations in 2D space are more suitable to understand it.
What if this concept of a hologram could be extended to the entire universe? What if, in reality, the universe is actually two-dimensional and what we see is only a 3D projection of it? All of this might be too much hypothetical but the holographic principle giving rise to a holographic universe could potentially solve one of the biggest mysteries in physics, the theory of quantum gravity. It was observed that a 2D universe can unify the theory of general relativity and quantum mechanics. Now, that would be cool as hell!
It is necessary to clarify that the holographic principle of the universe can probably never be verified. So, there’s no possible reason to prove that we live in a 2D world. Although existentialists can leave a huge sigh of relief. Personally, for me, the theory makes me more confused as an individual. The theory might not have any impact on our lives, but the ones who like to think, the ones who like to question reality, and the ones who truly strive to understand it, will continue to do so, and they will continue to tell themselves that we might be in a 2D universe.
But does it really matter? Will anyone really take you seriously if you tell them that the universe is 2D? On the other hand, does anything matter in life? If you think about it, nothing makes sense. So, why not just follow the thing that makes sense to us? Even if the world doesn’t understand, let’s continue to try to achieve our understanding of the ‘nonsense’ that we want to know about. And let’s continue to love physics.