I didn't say the rate of technological advancement was linear. The rate of technological advancement is not the same as the rate at which the amount of energy that can be stored in a battery increases over time. The chart I included used the readily available information about how much energy was stored in batteries over time. It's fact. You don't understand what Kurzweil means when he says that technology advances at an exponential rate. It doesn't mean that everything increases at an exponential rate. That's frankly ridiculous. The way you prove me wrong is by showing a chart that demonstrates that the amount of energy stored in batteries is increasing exponentially. Not by showing a chart of a different phenomenon.