The Big Bang also has an information paradox
Information paradoxes are not unique to black holes
Information paradoxes are not unique to black holes
Suppose you were transported back in time to where it all began. No, I don’t mean your birth. Further back. Back to a time when there was, well, nothing. Literally nothing as far as we know, not even time itself. The time of the Big Bang.
As far as we know, the universe started as an infinitely dense, infinitely hot point of matter and energy which then rapidly expanded. If you were to travel back to that time, you would also be compressed into an infinitely dense and hot point as well, not unlike being pulling into a black hole singularity.
Another similarity between the Big Bang and black holes is that both have an information paradox. The one involving black holes is well known. If you throw information into a black hole, theoretically, it is never coming out and there is no way for us to extract that information in any other form by, say, observing the black hole’s event horizon.
The Big Bang information paradox is less talked about but actually similar. Simply stated, the Big Bang began as a singularity, not in space like a black hole, but in time.
Because of how the Big Bang started from exactly nothing, it has the reverse problem from black holes. Instead of information being lost, the Big Bang must have created information from nothing. In fact, it created all the information there is.
This seems obvious but it is problematic from a physics perspective because quantum physics does not allow information to be created or lost. It must be preserved somehow.
One way to resolve the problem might be to suggest that the Big Bang was not the beginning of everything. In fact, the Big Bang may have formed from a black hole in another universe. This would allow for continuity of information and preserve quantum physics.
If the Big Bang formed as a black hole in another universe, it would solve a couple other problems including:
The Horizon problem where parts of the Cosmic Microwave Background are overly correlated with one another between different parts of the night sky, indicating that they must have either mixed before the Big Bang or from rapid inflation.
The Flatness problem where the universe is perceived to be spatially flat, with Dark Energy as the main culprit. The Black Hole Big Bang resolves that because the Black Hole can impart a spatially flat topology on the universe it creates from its own structure.
Oddly enough, this idea also resolves both information paradoxes provided you assume that all black holes are connected, internally, to Big Bangs, whether big or small. The key is that the connection offers a place for the information to come from and a place for it to go.
Alternative explanations may help with black holes, indicating that information is somehow radiated back out from the black hole. This doesn’t help with the Big Bang unless you assume it is just the continuation of a cycle of universes (a Big Bounce) or some similar situation that does not have a definite and abrupt beginning.
Another possibility is that quantum physics is just wrong and that information can be lost. We already know that energy is not necessarily conserved in Einstein’s general relativity, which describes both black holes and the Big Bang. Could it be that the Big-E also scraps information continuity?
Some quantum theorists believe so and that quantum mechanics regularly jettisons information from moment to moment. Every time a quantum coin is flipped, such as a particle being emitted or not, or deciding to follow one path versus another, all the information contained in the other possible outcomes is lost completely. If you subscribe to a quantum mechanics that allows “non-unitary” evolution of wavefunctions, then you are already abandoning information preservation.
Perhaps the Big Bang is just another example of, not information loss, but information gain from nothing. And if it can happen once, it can happen over and over again. Information may be emerging from nothing all the time and disappearing again.
If so, then quantum theory needs some rework. Perhaps all our equations describe not the real world but a non-existent set of probable outcomes, only one of which is reality.