Hopefully Interesting

See also parts  I ,   II ,  III ,  IV ,  V , and  VI . Space is sort of hard to get to.  You've got one of the Space Shuttle Main Engines (SSMEs), which are really efficient rockets which'll give you a v e  of 4.4 km/s in vacuum.  That's pretty efficient for burning stuff and about as well as we can do for a rocket that can take off from Earth.  But lets say we do want to take off from Earth.  Well, plugging that into the rocket equation we see that you need a mass ratio of  8.5 to 1 to get the 9.4 km/s you need to reach orbit.  Especially when the big tank you need to hold the hydrogen for your rocket probably has a mass ratio of 10 to 1 before you add in the engines or the shuttle and payload.  Thankfully the shuttle also had its boosters which finished burning early then the big casings that contained all that solid fuel were dropped into the ocean where they couldn't slow the rest of the shuttle down. Being able to drop heavy pieces of your rocket when you'r

When I was younger there were a lot of wondrous devices that were predicted in some science fiction books I read that I thought I might never get to use.  For instance when I was reading some Tom Clancy book or other in high school some government servant pulled out his pocket device that combined a cell phone, a GPS, and a PDA.  This was of course a super expensive device that was only available to top government officials and the very wealthy.  It was, of course, basically an iPhone but with less features.  There was another novel I read in college, Snow Crash , where the protagonist managed to get access to a piece of software normally reserved for the rich and powerful.  It was a 3D model of the Earth overlaid with satellite imagery that you could manipulate and zoom in on any location smoothly plus a lot of extra information.  It was basically Google Earth except with a few more features. Every technology has an adoption curve.  Once indoor plumbing was for the rich only but now