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Are Some Things About the Universe Fundamentally Unknowable? (forbes.com)
StartsWithABang writes: As we peel back the layers of information deeper and deeper into the Universe's history, we uncover progressively more knowledge about how everything we know today came to be. The discovery of distant galaxies and their redshifts led to expanding Universe, which led to the Big Bang and the discovery of very early phases like the cosmic microwave background and big bang nucleosynthesis. But before that, there was a period of cosmic inflation that left its mark on the Universe. What came before inflation, then? Did it always exist? Did it have a beginning? Or did it mark the rebirth of a cosmic cycle? Maddeningly, this information may forever be inaccessible to us, as the nature of inflation wipes all this information clean from our visible Universe.
No, there are no limits on our ability to comprehend the universe as its own observer, and if there were, we would not be here to observe it.
Happiness in intelligent people is the rarest thing I know.
Ernest Hemingway
I'm not saying you're wrong, because I don't know, but that doesn't make logical sense. Everything we have ever known has had a cause. We might not know what that cause is, but there has to be a cause there. It may simply be inaccessible to us. If the universe is everything we have ever known, then it's by definition not possible to know what came before it. But that doesn't mean that there was no before. It just means it's imperceptible to us. If you want to say that it makes no difference if there was a before, that's another matter, but it's not the same thing.
We already know there are questions we can't answer. In fact, it isn't that hard to write down questions where barring extreme surprises, we can't answer them even given that they are essentially just simple computations. For example, does 2^(10^(10^500)) +1 have an even or odd number of distinct prime factors? That took two seconds to write down, but unless there's something very weird about numbers close to powers of 2 then we literally lack the computational power in the observable universe to answer that question. So we already have pretty hard physical limits on what we can know. This is just a question of whether there are also hard physical limits to questions that some people happen to care a lot about.
Everything we have ever known has had a cause.
I disagree, we are ever in search of causes, precisely because our body of facts great exceeds our body of explanations. Some facts, such as quantum randomness, seem to explicitly exceed our ability to link a previous state to the final state except by statistical description.
Taking it for granted that we can uniquely relate all effects that we have observed with prior causes -- and even that we will never encounter a future exception -- on what basis can we assume this would apply when the universe was in a fundamentally different situation? In fact, we know some of our existing assumptions must break down, and it is one of the standing problems to understand how. But how can you assign a probability to rules like cause and effect under unknown conditions? Inside the scope of a basketball game, you can estimate the probability that a player, or a group of players, will score. What good is that estimate if I tell you their next game will be a newly invented sport with unknown rules?
But I think it's fine to assume things like an ultimate cause or chain of causes. It's not science, because it's not subject to observational inquiry. However, it may still be true. I just don't think it's something we can state as having to be true.
When things get complex, multiply by the complex conjugate.
Related to this is the problem of our mental ability to conceive of that which we have never experienced. Can anyone understand imagine a 4D space as more than just a mathematical model? How about the behavior of time as something that dialates? We can do the math, but we can't wrap our minds around the reality because our brains just aren't wired that way. What if the whole "everything has a reason" could be in the same category as the constancy of time - something obviously true but wrong. And because our brain refuses to accept any other conclusion we rationalize things that have no reason by supplying reasons. Even logic might have this problem. If A implies B and B implies C, then A implies true. Obviously and undeniably true according to our brains. Are our brains correct? We have a model of logic is internally consistent and that seems to work for us. We judge everything against that model. If that model is wrong then we'll never know.
I often don't like the choices people make, but I like the fact that people make choices. That's why I'm a conservative.
This thought line reminds of two things that keep it in perspective:
1 The TED podcast of January 4 "Have we reached the end of physics?" by Harry Cliff. He points out that there are some things that we can never know (or prove with any foreseeable technology.) Big surprise!
2 Charles H. Duell was the Commissioner of US patent office in 1899. Mr. Deull's most famous attributed utterance is that "everything that can be invented has been invented." Whether this is a correct attribution is irrelevant to this discussion.
It is possible that at some point the rate of new discoveries and ideas will diminish, but history has shown the opposite- a snowballing increase in human knowledge in almost every area. Of course we will never know it all, never be able to prove all that we do know, but we will keep on striving.
...omphaloskepsis often...