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Comment by stareatgoats | Hacker News Reader

Cosmology is not a done science. There are a great number of advances that have answered specific problems regarding the behavior of light and energy, mass and gravity and so forth, but our knowledge is not complete (and will likely never be).

Articles like this get traction because the lay person may have believed that the science was more mature than it is. (Some) scientists are also notoriously famous for exaggerating how much science "knows" - Stephen Hawkings claim to the mind of God comes to mind.

We need to relieve such scientists of the burden of needing to know it all, and be grateful for all the things still left to discover.

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Something not being a done science is one of the core assumptions of science to begin with. Any statement where further progress is excluded is not scientific in a strict sense.

In my opinion scientists (and everyone else) should be allowed, maybe even encouraged to fantasize. Fantasizing, play, shifting around assumptions can help progress. But the problem arises if we accept anything a scientists says as scientific truth.

Understanding that science is always evolving and that scientists often need play and fantasize, increases trust and accelerates progress. We need both to face the challenges of nature.

> Any statement where further progress is excluded is not scientific in a strict sense.

Then that is not a scientific statement.

Correct, the definition of words is not a science.

The study of the definition of words is Linguistics which is a science: https://en.wikipedia.org/wiki/Linguistics?wprov=sfti1

No, you are missing the point. The sentence contradicts itself. It is a statement that implies no further progress can be made about its claim.

Any statement about how science should work is indeed philosophy and not science, science is for obvious reasons incapable of defining itself.

No, the point is that the sentence contradicts itself. It is a statement that implies no further progress can be made about its claim.

The statement doesn't claim to be a scientific statement. It isn't contradicting itself.

So it implies itself to be non-scientific? I guess I can disregard it as nonsense then.

You can do whatever you want, but most of us don't try to operate in a system where the only knowledge that can exist is that which is verified by the scientific method. In fact, inherent to the scientific method is an underlying philosophy of science which does not come from science, nor could it without being at best circular reasoning.

Science and the scientific method is basically the best means by which we can understand the physical world, but it doesn't help us determine the nature of truth, ethics, or the nature of science. It works on various assumptions (e.g. physical matter actually exists, it is possible to gain knowledge about physical matter, there is such a thing as time, logic is a valid aapproach to determining truth) that it cannot validate.

> Cosmology is not a done science.

Cosmology will never be a done science. The universe is infinite but the human mind is finite.

Cosmology is not the study of the universe but only its large scale structure.

> The universe is infinite

Well, an open question in cosmology is whether the universe is actually infinite or not...

Strictly that's a question about philosophy, not cosmology. Cosmology just says the universe is unbounded and leaves it at that. In fact "The Universe", meaning all the matter or energy which we will ever even theoretically be able to obvserve, is definitely finite. The distance to the point of infinite redshift (where we're looking at the big bang, essentially) is finite. It doesn't make sense to talk about anything "farther" out.

Is that true? (Honest question) Whatever the “thing” was that exploded at the big bang (which I read once was the size of a grapefruit for what it’s worth) - could there not have been other similar “things”? And what about where that “thing” came from? I’ve read theories of the universe expanding, but then eventually falling back onto itself to recreate another “thing” that will explode again. Anyway, it feels like there might indeed be more.

A way that I heard this described, is that what we recognize as the observable universe right now was the size of a grapefruit at the beginning of the big bang. The stuff that expanded due to whatever the big bang actually did, that stuff could have been just the size of a grapefruit and nothing more, or itself infinite. But the part we can access given speed of light restrictions was the part that was the size of a grapefruit. There might actually be a lot more stuff out there ... we can just never get to it.

due to the isotropic principle we assume that the universe is infinite (because our vantage point is random, and since we don't see any orientation at the edge of the observable universe)

I picture the big bang as a bunch of heavy "black holes" approaching eachother discharging something that looks like lightening between them that grows more intense as they all pulled closer together. Eventually fusing into a persistent electromagnetic "explosion." Like a really bad welding accident.

> Cosmology just says the universe is unbounded and leaves it at that

I don't think that's right. The shape and topology of the universe is an open question in cosmology, and cosmologists haven't just "left it at that".

Let me be stricter: models consistent with general relativity don't discuss the idea of a universe being "infinite", and just in general theories in science don't predict the unobservable. Open universe topologies are unbounded. They aren't "infinite".

So is the set of all positive integers, but there is no unknown number in there, even though we haven’t seen them all.

There are plenty of unknown numbers :) For example, the number that is 1 if the Goldbach Conjecture is true, and 0 if it is false.

(BTW, if you want to know the difference between constructive and nonconstructive mathematics, it's that constructive mathematics doesn't let you say "well, it's definitely 0 or 1" because it leaves open the possibility that there's no proof of either termination or nontermination in the current theory... which is basically the philosophical distinction under discussion).

There is though, what’s the prime number after 314159265378979323846264338327950288419716939937510582090494459?

It's ....58209_7_494459... I checked against my memorized pi expansion. Oddly enough yours and mine stop at the same place!

You only need a hundred digits to know the circumference of the universe within the accuracy of the diameter of hydrogen!

In the book "When Einstein Walked with Gödel" by Jim Holt, It seems like that assumption is not as clear as it seems. I am not able to articulate it well enough and I don't have the book at hand.

If my recall is accurate then there is a bit of a question if there exists a "final number".

Is there such thing as any kind of done science? Sounds like an oxymoron to me.

> The universe is infinite ...

Yet we can describe most of what we observe with a tiny set of equations. What's more meaningful to science is that the universe is not bound to our models and assumptions. Even the assumption that the universe is ordered and so will remain ordered is not guaranteed. It's just a convenient and historically effective assumption that appears to be justified as far back as we can look. No science, therefore, is a done science.

> ...the human mind is finite.

A whiteboard is finite. It is bound in spacetime and no matter how small the writing, there is an upper limit to the amount of information that can be displayed on it at any one time. No matter how quick the erasing, there is an upper limit amount of information that can be displayed within the lifetime of the board.

Despite this, it can have an uncountably infinite variety of information impressed upon it.

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