So yeah. Anyone got any good resources for this course? Online and off are both appreciated.

-----

On a side note, this is kinda neat.

Long ago in a galaxy far away...

the technological terror known as the Death Star aimed its weapons at the peaceful planet, Alderaan, and, just for jollies, shattered it into countless fragments that still drift endlessly through the universe to this very day. You probably recall the exact scene of Alderaan's destruction from the movie, Star Wars. Surely the Death Star had enormous energy resources at its disposal. But the question that was undoubtedly gnawing at the minds of many a viewer after having seen the movie was, "Exactly how much energy does it take to fragment an entire planet?" Well thanks to what you've learned in last few sections, along with a little basic physics that I will tell you now, you have become equipped to answer this mystery.



... Check here for all the actual math work.



To give you some idea of how much energy that is, the total radiated output of the sun (not just what falls on the earth, which is only one part in 2.2 × 109 of the sun's total output, but what goes off in all directions into space as well) is 3.9 × 1026 watts. So it would take about 590,000 seconds for the sun to radiate that much energy. That's about 4 hours short of a week. Looking at it another way, according to Einstein's famous equation, E = mc2, (where c is the speed of light, about 3 × 108 in meters per second), the Death Star would have to convert 2.5 trillion tons of matter completely to energy in order to destroy the earth. I doubt if the Death Star even weighs that much.

What it boils down to is that the numbers having to do with things astronomical (such as gravitational binding energy of a planet) are -- well -- astronomical.

I hope that puts your mind at ease. The earth is way too tough a planet for the Death Star. So stuff that into your shiny black helmet, Darth Vader.