I have many problems with Day of the Advent. Some episodes of Big O tend to stretch the laws of physics, but Day of the Advent completely ignores them. I'm a physics major, so this sort of thing bothers me.
When I see a gigantic falling object crashing into earth from orbit, I know that it has several properties, such as mass, ever-increasing velocity, and a constant acceleration of 9.81 m/s^2...
Recall the equation for Kinetic energy is 1/2(mass)(velocity^2).
Think about that for a second. The Earth's atmosphere extends about 1000 km upwards (
http://www.rcn27.dial.pipex.com/cloudsrus/atmosphere.html), So something in freefall, weighing 1000N, with a cross-sectional area of 5 sq meters, would reach a terminal velocity of 22.68 m/s (calculated here
http://exploration.grc.nasa.gov/education/rocket/termvr.html)
The kinetic energy released in the impact would be: 26215.49 Joules.
1000N = 101.93 kg
Packs quite a punch, doesn't it; considering its close to the weight of a large human, and bit bigger surface wise.
HOWEVER.... The object in Day of the Advent did not enter the atmosphere from free-fall... it entered on an angle, and therefore would have been falling for a longer time. Considering it was oblong and slightly aerodynamic, its terminal velocity would be much bigger. I don't have exact measurements, but if I had to guess, it was probably coming in at 50-70 m/s. For an object of its size (It was, after all, about the combined size of Big O's arms), its impact with the ground would have been immense. Not to mention that its momentum component (mass * acceleration) would have been behind it the entire way.
Now, given all this information, Big O simply could not have destroyed the falling object. Big O's piston punches would have to be immeasurably powerful in order to accomplish this feat. There would have to be enough force in just one of those punches to not only equal, but overpower the entire kinetic energy AND momentum behind that satellite. Sorry, I just don't see that happening... ever.
Also, this is completely ignoring the notion that the impact of the satellite hitting Big O's fist would have been THE SAME AS IF IT HIT THE GROUND. IT STILL SLAMMED INTO SOMETHING, DIDN'T IT?
The shockwave would have still taken out most of the city. And yet, the buildings and people partying at Big O's feet are completely unscathed...
There's also the issue of if Big O can equal the force of a gigantic falling satellite FROM ORBIT, why didn't it destroy Bonaparte with a single punch? What about when Big Duo Inferno punched out Big O... are you telling me that Big Duo Inferno had more force behind it than a gigantic satellite falling from orbit? Don't even get me started about Big Fau's force field...
Apart from the blatant and utter abuse of physics in this episode, the plot is also pretty lacking :/
It could have been done SOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO much better.