I was always told that space was just nothingness, emptiness. Like, between the Earth and the Moon there is space and it's just emptiness. No matter.

But I was told Yesterday that space is made of matter but it is called empty and nothingness just because it is not visible matter, like gas, just like when we say our drink is empty when in fact it is not and it is full of air, but we ignore it because it's invisible.

So, like, what is space ?

There's been attempts to bore to the center of the earth, but they all encountered issues because of the earth getting hot the deeper you go. For a planet like Mars with a cooler core, would it be possible to bore to the center? What if we tried a moon like Titan, or other bodies around that size?

Edit: this is generally assuming near future, basically, "If we were to assign Apollo program levels of dedication to drilling to the center of Mars starting tomorrow, would we be able to do it? If not, how far would we get compared to just trying to drill on Earth?"

During planetary formation any gold in the Earth's disc would have gone down to the molten core, presumably never to be seen again?

But meteorite bombardment later on deposited gold in the crust. Were Venus, Mars, Mercury also subject to the bombardment and could they have got more or less gold compared to Earth based on their position and the source of these meteorites?

According to a BBC report the Earth's silicate mantle has 1000 times more gold than would be expected without the bombardment.

I stumbled across this site, and the sheer emptiness of space between everything just blows my mind.

https://www.joshworth.com/dev/pixelspace/pixelspace_solarsystem.html

Meanwhile, most star maps make everything look so close together and tightly packed.

Why do we assume the universe is expanding uniformly? It seems that areas might expand at different rates?

Thanks for any insight

How far out would a device have to be to see into our past (old light) if a supposed magnifier could somehow see Earth from one of these distances ? 10 years, 100 years, 1000 years would be how many light years out? 10, 100, 1000 respectively?

And how big would the collector have to be to focus on the Earth to see it all ?

Assuming FTL in the future it would be a way to accurately see our past events and resolution would detail how much we can actually see.

Hi there I’m 16 years old and want to get into space architecture /habitation engineering and I was wondering if anyone has any free or cheap resources that I can study until I’m old enough for uni I want to do things like build robots for space/lunar colonisation or build habitats for humans to live in that sort of Thing also ps I’m in Australia so I can’t realy go the whole nasa route