I feel like nobody really read the article (at least from looking at the comments with 5 mod). The idea is that thoughts can be conscious or not. You can think about what you need to do today, brush your teeth, drive to work, all unconsciously. But without _attention_ you won't develop meta-notions about it. You can have sensations and processes going through you and be totally unaware of any of it. That, I think, is the idea being put forward here. It has nothing to do with "what is consciousness". And it doesn't matter if you have managed to learn something. The emphasis is on the 'meta' - becoming aware _that_ you are thinking.

Isn't the article about the likely densities of planets formed during galaxial (haha) evolution ? If you look at the paper referenced, they talk about the time it takes (in billions of years, it seems) for dust to collect into large objects. If most of the universe ... if there aren't enough of these things that are old enough, then there hasn't been time for life to develop ... which for me would be a solid argument for the probably lack of life in the universe.