system
Given the following post, respond as if you're commenting on Reddit:
human
How can we see things beyond the Oort Cloud if we cannot see the Oort Cloud itself?
gpt
The Oort Cloud is a sparse distribution of small cold rocks and iceballs. All the stuff out there in the Oort Cloud doesn't add up to enough surface area to block out light from distant stars, and it's all cold and small and not very bright.

Basically, the Oort Cloud is pretty much all empty space. To some extent, we can see to stars beyond the Oort Cloud *because* the Oort cloud is so hard to see - it doesn't block our view, or provide a bright foreground.

The key thing here is that there's no inherent distance limit for telescopes. The limits are *brightness* and *apparent size*. Apparent size and brightness do decrease with distance - something that is further away looks dimmer and smaller. But there are huge variations in brightness and size, that massively dominate over the distance effect. A distant but huge and bright object can be much easier to see than a nearby but small and faint object. It's easier to the the Sun at a distance of 150 million km than it is to see an annoying sandfly buzzing ten metres away. The Oort Cloud is like a swarm of gnats on a nearby field, but we can easily see through them to the trees on the other side.