It is very simple. You just have to trust persons who are experts in their fields, such as those at the astronomical observatories to give you the answers. You just have to trust your instructors. If you don't know little or anything about anything you have to do some study to learn about it. Most engineers and scientists started out in first grade, too, like anyone else. They just continued on studying and learning farther than other persons.
There you go, trust authority, trust your teachers, professors, doctors, government, the pope, the media, Coca Cola, McDonald's, Walmart, Hitler, Stalin and Mao.
I'll trust them enough to listen to what they're saying, but that's it, if I have questions, I'll ask them, and if I spot what I think are holes in what they're saying, I'll call them out.
I'm not going to trust their claims without something I can empirically verify.
Most teachers don't verify anything they've been taught, so they actually don't know anything.
Engineers can often use what they've been taught, so I take little issue with that.
That's actually probably the best form of verification, being able to use something.
If you can use it than they must be right about something, althou they may not be verifying everything they're teaching.
The trouble is no one, except for NASA and some other government space agencies can supposedly use 'factoids' like the sun is 149.6 (I love how specific they are about something they've never been to, and can never go to. Not 150 million kilometers, 149.6, how do you like that? Next year they'll say it's actually 149.8, and a few decades from now they'll say it's actually 188.295. Derrr, can we all just agree it's really, fragging far??? But that's just it, maybe it's much, much closer...or further than they think or say they know.) million kilometers away, so you can't verify it that way, by using it to do something the way an engineer does, so how can you verify it?