LOGBOOK N°77 DECEMBER 2043

PARADOX INFORMATION

It’s been a while since I wrote in my logbook and well, things have not been doing well in space. This journey can bring us some bad surprises…

However, today, I have time to continue my logbook and more precisely continue what I started last time, the story that revolves around information. I managed to write a logbook and try to share it with you myself but, will it ever reach you? In the hypothesis where my journey ends up at the bottom of a black hole if we may say, in theory, we would be able to have access to everything by catching and assembling each atom that has been disassembled and put it in the position where it was. By doing so, we would be able to retrieve what has been destroyed.

So, you may wonder what the link is with losing information if we could in theory reconstruct it. Well, black holes in all their mystery bring us problem. It’s what we call the information paradox. 

In fact, it’s paradoxical because the laws of physics say that nothing -particularly information- can disappear, but it can change its form. However, British scientist Hawking came up with a theory saying that black holes are ‘evaporating’. Extremely slowly, but surely. What could potentially be a problem is that the information that is suck in would be lost forever. Indeed, as mentioned previously, black holes can suck in literally everything. And, by saying that, also information that is present in the Universe. So, all the indication about the creation of the Universe would disappear into the black hole. 

But, why is it so important? Information is crucial to understand how things are made, how the world is what it is now. As, you may probably know, everything in the Universe is made up of the same atoms. Take the same number of atoms from an object and change their arrangement and you will get something totally different. So, if it weren’t because of the arrangement of atoms, everything in the Universe would be the same. 

How exactly do black holes evaporate and what does eventually evaporate? Before the discovery of the Hawking radiation, scientists thought that everything including information is trapped in the black hole, so is in theory secured. However, in the 1970’s, Hawking with his theory of black holes evaporating their mass shakes all this up. In fact, a black hole has to evaporate especially when its temperature pass over the cosmic microwave background one’s. To put it simple, the cosmic microwave background (CMB) is an electromagnetism radiation which can be observe in every direction of the Universe and showed up a few years after the Big Bang. At that time, the Universe was smaller than now and the CMB was hotter. Now, its temperature has decreased because of the expansion of the Universe and stagnates now at 3 Kelvin (-270,15°C). So, that is why, black holes are evaporating because of thermal diffusion. Just to set up everything, basically thermal diffusion result in hot things -here mass of black holes, temperature: 10 billion degrees to say the least- “going” or “traveling” to cold things (CMB at -270,15°C). But to make this diffusion possible, a black hole has to emit particles that carry thermal energy. And those types of particles don’t carry information because the process is unpredictable. Hence, information could be lost forever. Doesn’t sound good…

Regardless of what it is, what could be the various scenarios to this… Information is lost forever.  Or from what Hawking came up with a few years later, there is a potential solution for this information paradox. In fact, the information could be stored on the surface of the black hole (the event horizon) and not inside. So, due to the evaporation of the black hole, the information could be get back. Another possibility is that black hole could split a part of itself and create a new Universe and so the information could be stored here. 

I have to end my logbook now. But keep in mind that every theory is just a theory and needs to be proven.