About a third of the way into the Sun, the density is the same as that of liquid water on earth. But, the Sun is mostly made of hydrogen, the lightest gas. The center of the Sun (mostly helium) is something like the density of iron. It is crazy to think that you could compress such a light gas so much that it becomes as dense as water or iron…
The nanomaterials I work with are so small that light can’t even see them, it would be like trying to pick up a grain of rice with 50 pairs of gloves on your hand. Light, like your hand would be completely insensitive to see or interact with things at the nanoscale
We only know what 4% of the Universe is made of. That 4% includes all the stars, galaxies and so on that we can see.
96% of the Universe is dark matter and dark energy, things we can’t see or detect (but they’re definitely there). We have no idea what these are. Most of the Universe is a total mystery to us.
When a telescopes take pictures distant stars they are SO far away and the light takes SO long to reach the telescopes that some of the stars you see don’t even exist any more! They have died in the time it took the light to reach the telescope. So telescopes are a bit like time machines allowing us see how stars looked in the past.
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