When we look at the sky, there is a line where there is way more stars than usual. This line goes all the way around the sky. This was called the milky way by the Greeks because it was like a road sparkled with milk drops. At some point, we deduced that we were in a group of stars arranged in a flat disk. Later, we realized that some weird space clouds (nebulae) were much further away than we thought and were actually other huge groups of stars like our own that we named galaxies, still after milk.
There are more details me course. Even along the line in the sky drawn by the milky way, there is one side where there is much more stars and dust than the other. We deduced that we were at the edge of the disk and the bright region was the center of our galaxy. Also, the amount of gas and dust that block certain types of light that teach us that our galaxy has arms.
That’s definitely the more PG-13 version of why the ancient Greeks called it the Milky Way lol. Alternate version from Wikipedia:
In Greek mythology, Zeus places his son born by a mortal woman, the infant Heracles, on Hera’s breast while she is asleep so the baby will drink her divine milk and thus become immortal. Hera wakes up while breastfeeding and then realizes she is nursing an unknown baby: she pushes the baby away, some of her milk spills, and it produces the band of light known as the Milky Way.
Great explanation, although I want to clarify that not all nebulae are galaxies. Nebulas are massive clouds of dust and gas that are found within galaxies. Other galaxies were previously thought to be nebulas in space outside of the Milky Way, called extragalactic nebulae. However, in the early 1900s it was proven that these were actually other galaxies and not nebulas, so the term is no longer used.
While there are nebulae in other galaxies, they are not easily visible to us, so the word nebula generally refers to those contained within the Milky Way.
Cool. I was trying to figure out if there was a bovine with the root word Andromeda in it. Because there are dromedary animals. But even do that only got me as far as one Galaxy.
Imagine being on the surface of Saturn. You’d see the rings. I mean, you’d be dead, but you get my point I hope. If not, picture Saturn being the size of rock, but the rings were still there. You’d still see them, yet you’d be “in” Saturn.
We’re on the Earth — how do we see the Earth? By seeing other parts of the Earth that aren’t ourselves. The same is somewhat true for the Milky Way. And like on Earth, you can’t see the whole thing without leaving it, because we only get to see the stuff that isn’t blocked by other things.
Because we are inside it. You can literally just look up at the sky and there it is! It does help that we are more toward the edge of it, than towards the center.
As for like a zoomed out image of the entire thing? Math as well as microwave and other radiation maps taken with powerful telescopes and instruments either on Earth or in orbit. Most of the images of space you might see are doctored in a way to make them look better to human eyes; they were actually constructed from data that wasn’t necessarily visual. All the different colors of a rainbow nebula, for example, mean something, and the nebulas do not actually look that cool when seen with the naked eye.
To add to that about the nebulas, they don’t look like they do I’m scifi either. Gas clouds or plasma clouds visible to the human eye. If you piloted a ship through most nebula it would look no different than the rest of space around you. Space is BIG yall