We Explain the Seen in Terms of the Unseen
Now people might object at this point and go, "How dare you invoke in science things that cannot be seen, things that cannot be observed? This is completely antagonistic towards the scientific method!"
Surely, and I'll say to anyone who's thinking that right now, almost everything of interest that you know about science is about the unobserved. Let's consider dinosaurs. Dinosaurs are unobserved. You say, "Oh hold on, I've been to the museum, I've seen a dinosaur!"
Now you have seen a fossil, and a fossil isn't even a bone. It's an ossified bone; it has been metamorphosed into rock. So no one has ever seen a dinosaur. We have seen things that look like dinosaurs and interpreted them to be huge, reptilian, bird-like creatures. When we assemble their skeletons, we make up a story about what this thing was that walked the Earth tens or hundreds of millions of years ago.
In the same way, no one has ever seen the core of the sun, and no one will ever observe the core of the sun. But we know about stellar fusion. We know that hydrogen nuclei are being crushed together there to form helium, and in the process, producing heat.
We don't see the big bang. We don't see the movement of continents. Almost everything of interest in science we do not observe. Even many of the things that we say we have seen, we've actually just seen instruments detect those things. So we're watching the effects through instruments and then theorizing that there are other universes out there, where the photons are interacting with the photons that we can see.