Virtual Nerd

There is nothing more pleasing to us here at Virtual Nerd than science popping up in movies, and the science in Iron Man is both fun and literally unbelievable. In one part of the movie, Tony Stark, a weapons mogul and science uber-genius, makes a miniature arc reactor that supposedly outputs 3 Giga Joules of energy every second. So you might wonder, just how much energy is that, and how come we don’t invest our tax dollars in arc reactor technology, instead of drilling in Alaska?

Well, lets do a fun and quick calculation to just get an estimate. You may have learned and forgotten that power is energy divided by time, and comes in units of Watts:

So this reactor that Tony built is a 3 Giga Watt reactor. Now Giga means billion, so that’s a lot. A burning question might be:

How does the arc reactor compare to nuclear power?

Well, in the US last year all the nuclear power plants combined generated 700,000 million killowatt hours of energy. To convert back to the average power of all these plants we need to divide this number by the number of hours in a year, which is 24*365. That gives us about 100 GigaWatts of power generated by all the nuclear plants in the US. That means Tony needs to make just about 50 arc reactors to replace all the nuclear plants in America. And 50 arc reactors would probably fit into a large hiking backpack, so and we can only scratch our heads and wonder why this hasn’t happened yet. I guess we’ll have to wait and see if Steve Jobs announces the iArc reactor at MacWorld next year.