Nothing is particularly screwy in our own close-up neighborhood of space (at least outside Washington). A galaxy in the local Virgo super-cluster is about 50 million light-years away, so its light took that long to get here. That's short compared with its age, so its image is therefore a current, accurate snapshot. Also, the distance from here to the Virgo galaxies grows by 700 miles every second, thanks to the universe's expansion. This red-shifts their light, making them slightly dimmer. The effect is barely noticeable, since their recession is less than one percent of light speed. Even if we jump 20 times farther and observe any of the 60 million galaxies that float within one billion light-years of Saugerties, we see them essentially how they look today.
But now the fun begins. Because the speed of the expanding universe increases with distance, weird stuff happens to truly faraway objects. Take one of the newfound distant galaxies. We can say that it's old, because we see it as it was when its light started traveling to us 13 billion years ago. Its image is ancient. We can also say that it's young, because we're viewing a picture of a newborn galaxy.
But is it really 13 Gly away, as the news articles claim? Does it even make sense to compare where we are now with where that galaxy was 13 billion years ago? When the image that we're seeing left that galaxy, it was much closer to us. It was then only 3.35 Gly away. So it should logically display the size of a galaxy at that nearer distance, when its light left, rather than the distance that its image had to cover in order to get here. A photograph's dimensions don't change just because it took a long time to get delivered.
Amazingly, that galaxy indeed looks larger than we'd expect for something so far away. It measures just one-fourth the angular size of nearby Virgo galaxies of the same type. If it were 13 Gly away, it should appear 1/260 the size of Virgo galaxies. Holy cow! It's like a funhouse mirror. The galaxy appears much closer than it is!
In size, that is; but when it comes to brightness, the opposite is true: It's far dimmer than we'd expect a 13 Gly object to be. Space has been stretching all the time that its image traveled, dramatically red-shifting and weakening it. It now exhibits the ultra-faintness of a galaxy at the impossible distance of 263 billion light-years.
Let's put all this together: It's the oldest galaxy image we've ever seen, making it also the youngest. It looks way too big for its distance, but also way too faint. Could things get any weirder?
You bet. Science articles say it's 13 Gly from here because distance is often expressed that way. But that's merely how long its light took to reach us. During all that time, that galaxy has meanwhile been madly receding. It's now actually 30 billion light-years away.
Using all this logic, let's consider the universe's boundaries. If the first star clusters or protogalaxies formed 100 million years after the Big Bang, they'll display angular sizes as if they're just 1.2 billion light-years away. But their brightnesses would indicate an inconceivable distance of 1.2 trillion light-years: utterly undetectable. Their actual distance today is 38 billion light-years. These parameters roughly mark the edges of the observable starry universe.
But objects do not end there. Most galaxies were never positioned for their light to be able to arrive here at all. At least 98.4 percent of the universe lies "over the horizon" in a zone that can never be observed. This can be a frustrating limitation. For example, something massive is disrupting the universe's smooth expansion in our region of space. Some sort of "great attractor" lies in the direction of Centaurus. Many astronomers think that it's located outside our observable reality. It tugs on our visible universe from a place beyond.
That "place beyond" constitutes nearly all of the Cosmos. And where does that end? No one's sure, but the modern figures for the overall density and expansion rate indicate that the universe is, was and always will be infinite in extent. If so, everything that we can ever see represents zero percent of the universe.