I can't wait for this movie... some questions though about Stark's glowy pacemaker... why is it glowy?
Why Tony Stark's pacemaker is glowy (Spoiler)
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Stark's pacemaker is not a pacemaker at all but a magnet to keep pieces of shrapnel around his heart from moving further into his heart. This makes more sense when explained in the movie. Originally this magnet was powered by a car battery that Stark had to carry around with him while in captivity. He and a fellow captive built a miniature "arc reactor," a technically impossible energy source (I am betting vacuum energy) capable of an insane amount of power (3GW- compare to the Delorean needed only 1.21GW to travel through time). This is the source of power that keeps both his heart going and powers his mechanical suit.