Hm, I've been thinking about what people are actually talking about, and I came up with two statements:
''Absolutely measured, we know less about space than about the ocean.''
''Relatively measure, we can see less of the ocean than of space.''
Absolute/Relative:
Let's say there are two rooms in front of you. Room Space and Room Ocean. Room Space has 50 objects, 20 of which are identified. Room Ocean has 10 objects, 2 of which are identified.
Absolutely, Room Space contains more unidentified objects than Room Ocean: 30 versus 8.
Relatively, Room Ocean contains more unidentified objects than room Space: 80% versus 60%.
Knowing/Seeing:
When we look up to the universe with our naked eye, at night, we can already see tons of stars. Sometimes you can even see other planets of our solar system, or witness a meteor shower. And often enough, we can see the moon and its magnificent craters. Yet, at the same time;
We don't know what is below the atmosphere of Uranus and Neptune, or if there is life on Europe. We don't know how many other planets even come close to resembling Earth.
When we look into the ocean, you can't see much deeper than a few feet. Everything below that is too obscure. We can hear The Bloop, but what it is? The bottom of the ocean is even so dark and has so many treacherous areas that it's almost impossible to see every part of it. However;
We know a great number of species that live down there and what their life is like. We know various geographical areas and how some of them behave.
Conclusion: I think that ultimately, there are more things we don't know about space, than there are things we know about the ocean. But for now, it is much more difficult to look into the ocean, while we can see a great number of lightyears into space. So I repeat the statements I came up with:
''Absolutely measured, we know less about space than about the ocean.''
''Relatively measure, we can see less of the ocean than of that space.''
Please comment on my thought process if you disagree. Even on a forum I am always in pursuit of knowledge.