Airships demonstrate a law of increasing returns: doubling the length increases the surface area (and hence weight) by a factor of four while the volume (and hence lifting capacity) goes up by a factor of eight.
Thanks to a complete redesign of the internal architecture, the volume and weight of the new PS3 has been reduced by more than half compared to the very first PS3 model with a 60GB HDD, and by 20% and 25% respectively compared to the current PS3.