I been trying to find this out online, but i've not been able to find an answer. I've seen that they have found a few new ways recently to produce entangled pairs. My question is this, whats the furthest distance that an entangled pair has been separated in the lab, but yet has still remained entangled when observed / measured?

I heard from my teacher, that its not possible to see Atoms, because they are "energy levels",

but I saw here and there silhouette pictures from atomic structures.

Most artist renderings of the Big Bang depict an explosion that goes in one direction and can best be described as the muzzle blast from a shotgun where the gases and debris take off in one direction.  Why is this?  Would not the Big Bang expand in all directions simultaneously just like when a supernova occurs?

Everybody has heard the expreession "There are more stars in the universe than grains of sand on all the beaches and deserts on Earth".  This is said from classrooms to TV shows and used to illustrate the unimaginable vastness of space. Science seems to know how may stars on average there are and the approximate number of galaxies and someone must know the average number of grains in a kilo and hence on a 100,000 tonne, small beach and so on from there.

Has anyone who knows sand and geography done the math? Are we really only talking surfers paradise and throw in a small desert or does this overused phrase has some validity?

At our current technological level, if humanity pulled its economic resources together to fund such a project, which would be the most feasible planet in our solar system to terraform (as in, would it be easier to warm up mars or cool down venus)?

I assume that most of the water on our planet came from the inter-solar "soup" which formed into our planets whether through the initial formation of our planet or through impacts from moisture laden comets.  If so, where did that water come from? 

Since all heavy elements were formed inside of stars, what was the process where such large amounts of oxygen and hydrogen teamed up to form water?  Water seems to be a competent of all planetary bodies (obviously, some more than others), and the stuff is still whizzing by us periodically in the form of comets.

How could such huge amounts of water come into existance?

Thank-you.